U.S. patent application number 15/432278 was filed with the patent office on 2017-06-01 for camptothecin conjugates of anti-cd22 antibodies for treatment of b cell diseases.
The applicant listed for this patent is Immunomedics, Inc.. Invention is credited to David M. GOLDENBERG, Serengulam V. GOVINDAN.
Application Number | 20170151356 15/432278 |
Document ID | / |
Family ID | 45096373 |
Filed Date | 2017-06-01 |
United States Patent
Application |
20170151356 |
Kind Code |
A1 |
GOVINDAN; Serengulam V. ; et
al. |
June 1, 2017 |
Camptothecin Conjugates of Anti-CD22 Antibodies for Treatment of B
Cell Diseases
Abstract
Disclosed herein are compositions and methods of use comprising
combinations of anti-CD22 antibodies with a therapeutic agent. The
therapeutic agent may be attached to the anti-CD22 antibody or may
be separately administered, either before, simultaneously with or
after the anti-CD22 antibody. In preferred embodiments, the
therapeutic agent is an antibody or fragment thereof that binds to
an antigen different from CD22, such as CD19, CD20, CD21, CD22,
CD23, CD37, CD40, CD40L, CD52, CD80 and HLA-DR. However, the
therapeutic agent may an immunomodulator, a cytokine, a toxin or
other therapeutic agent known in the art. More preferably, the
anti-CD22 antibody is part of a DNL complex, such as a hexavalent
DNL complex. Most preferably, combination therapy with the
anti-CD22 antibody or fragment and the therapeutic agent is more
effective than the antibody alone, the therapeutic agent alone, or
the combination of anti-CD22 antibody and therapeutic agent that
are not conjugated to each other. Administration of the anti-CD22
antibody and therapeutic agent induces apoptosis and cell death of
target cells in diseases such as B-cell lymphomas or leukemias,
autoimmune disease or immune dysfunction disease.
Inventors: |
GOVINDAN; Serengulam V.;
(Summit, NJ) ; GOLDENBERG; David M.; (Mendham,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Immunomedics, Inc. |
Morris Plains |
NJ |
US |
|
|
Family ID: |
45096373 |
Appl. No.: |
15/432278 |
Filed: |
February 14, 2017 |
Related U.S. Patent Documents
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Application
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14337336 |
Jul 22, 2014 |
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15432278 |
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13774526 |
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14337336 |
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13213245 |
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8420086 |
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13774526 |
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13164275 |
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13213245 |
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12629404 |
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13164275 |
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12026811 |
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7591994 |
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12629404 |
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11388032 |
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8877901 |
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12026811 |
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10734589 |
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7585491 |
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11388032 |
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61375068 |
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61207890 |
Feb 13, 2009 |
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60668603 |
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60728292 |
Oct 19, 2005 |
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60751196 |
Dec 16, 2005 |
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60433017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07K 16/3061 20130101;
A61K 9/19 20130101; C07K 16/2803 20130101; C07K 2319/70 20130101;
A61K 51/1027 20130101; C07K 2317/732 20130101; C07K 16/2863
20130101; C07K 2317/734 20130101; A61K 2039/505 20130101; A61K
47/6859 20170801; A61K 39/39558 20130101; A61K 51/1096 20130101;
A61K 2039/507 20130101; C07K 16/30 20130101; C07K 2317/565
20130101; C07K 2317/51 20130101; A61K 47/6803 20170801; C07K
2317/73 20130101; C07K 2317/35 20130101; A61K 47/6867 20170801;
A61K 47/26 20130101; A61K 47/6849 20170801; C07K 16/2833 20130101;
A61K 51/1069 20130101; A61K 47/6809 20170801; A61K 47/6889
20170801; C07K 16/1063 20130101; C07K 16/2887 20130101; C07K
2317/55 20130101; C07K 2317/77 20130101; A61K 47/6883 20170801;
A61P 35/02 20180101; C07K 2317/24 20130101; A61K 47/6851 20170801;
C07K 2317/31 20130101 |
International
Class: |
A61K 51/10 20060101
A61K051/10; A61K 47/26 20060101 A61K047/26; A61K 39/395 20060101
A61K039/395; A61K 9/19 20060101 A61K009/19; C07K 16/28 20060101
C07K016/28; C07K 16/30 20060101 C07K016/30 |
Claims
1-24. (canceled)
25. A method of treating a B cell lymphoma or B cell leukemia
comprising administering to a human with a B cell lymphoma or B
cell leukemia, an immunoconjugate consisting of (i) an anti-CD22
antibody or antigen binding fragment thereof; and (ii) at least one
therapeutic agent attached by a chelating agent to the anti-CD22
antibody or fragment thereof, wherein the therapeutic agent is an
alpha-emitting radionuclide, wherein the anti-CD22 antibody or
fragment thereof comprises the light chain complementarity
determining region (CDR) sequences CDR1 (KSSQSVLYSANHKYLA, SEQ ID
NO:1), CDR2 (WASTRES, SEQ ID NO:12), and CDR3 (HQYLSSWTF, SEQ ID
NO:3) and the heavy chain CDR sequences CDR1 (SYWLH, SEQ ID NO:4),
CDR2 (YINPRNDYTEYNQNFKD, SEQ ID NO:5), and CDR3 (RDITTFY, SEQ ID
NO:6).
26. The method of claim 25, wherein the radionuclide is Th-227.
27. The method of claim 25, wherein the radionuclide has a decay
energy in the range of 2,000 to 10,000 keV.
28. The method of claim 25, wherein the radionuclide has a decay
energy in the range of 3,000 to 8,000 keV.
29. The method of claim 25, wherein the radionuclide has a decay
energy in the range of 4,000 to 7,000 keV.
30. The method of claim 25, wherein the anti-CD22 antibody or
fragment thereof is epratuzumab.
31. The method of claim 25, further comprising administering to
said individual an anti-B cell antibody or antigen-binding fragment
thereof that binds to an antigen selected from the group consisting
of CD19, CD20, CD21, CD22, CD23, CD37, CD40, CD40L, CD52, CD80 and
HLA-DR.
32. The method of claim 31, wherein the anti-B cell antibody or
fragment thereof binds to CD20.
33. The method of claim 32, wherein the anti-B cell antibody is
selected from the group consisting of GA101, BCX-301, DXL 625, L26,
B-Ly1, MEM-97, LT20, 2H7, AT80, B-H20, HI20a, HI47, 13.6E12, 4f11,
5c11, 7d1, rituximab and veltuzumab.
34. The method of claim 32, wherein the anti-B cell antibody is
rituximab or veltuzumab.
35. The method of claim 32, wherein the anti-B cell antibody or
fragment thereof comprises the light chain
complementarity-determining region (CDR) sequences CDR1
(RASSSVSYIH; SEQ ID NO:7), CDR2 (ATSNLAS; SEQ ID NO:8), and CDR3
(QQWTSNPPT; SEQ ID NO:9) and the heavy chain variable region CDR
sequences CDR1 (SYNMH; SEQ ID NO:10), CDR2 (A1YPGNGDTSYNQKFKG; SEQ
ID NO:11), and CDR3 (STYYGGDWYFDV; SEQ ID NO:12).
36. The method of claim 30, wherein the B cell lymphoma or leukemia
is selected from the group consisting of mantle cell lymphoma,
multiple myeloma, Hodgkin's lymphoma, non-Hodgkin's lymphoma,
diffuse large B cell lymphoma, Burkitt lymphoma, follicular
lymphoma, acute lymphocytic leukemia, chronic lymphocytic leukemia
and hairy cell leukemia.
37. The method of claim 36, wherein the disease is mantle cell
lymphoma.
38. The method of claim 25, further comprising killing B cells by a
mechanism selected from the group consisting of homotypic adhesion,
loss of mitochondrial membrane potential, production of reactive
oxygen species, increased phosphorylation of ERKs and JNK,
downregulation of pAkt and Bcl-xL, and enlargement of
lysosomes.
39. The method of claim 25, wherein the anti-CD22 antibody is a
G1m3 allotype.
40. The method of claim 25, wherein the anti-CD22 antibody is a
chimeric, humanized or human antibody.
41. The method of claim 25, wherein the anti-CD22 antibody or
fragment thereof comprises human IgG1, IgG2, IgG3, or IgG4 constant
regions.
42. The method of claim 30, further comprising storing the
immunoconjugate prior to administration at a pH in the range of 5.5
to 7.5 in a solution comprising a buffer selected from the group
consisting of 2-(N-morpholino)ethanesulfonic acid (MES),
N-(2-acetamido)-2-iminodiacetic acid (ADA),
1,4-piperazinediethanesulfonic acid (PIPES),
N-(2-acetamido)-2-aminoethanesulfonic acid (ACES),
N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES),
N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), and
N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) or
HEPES.
43. The method of claim 42, wherein the buffer is 25 mM MES, pH
6.5.
44. The method of claim 42, wherein the solution further comprises
trehalose and polysorbate 80.
45. The method of claim 44, further comprising lyophilizing the
solution and storing the lyophilized antibody at 2-8.degree. C.
46. The method of claim 30, wherein the B cell lymphoma or leukemia
is selected from the group consisting of mantle cell lymphoma,
multiple myeloma, Hodgkin's lymphoma, non-Hodgkin's lymphoma,
diffuse large B cell lymphoma, Burkitt lymphoma, follicular
lymphoma, acute lymphocytic leukemia, chronic lymphocytic leukemia
and hairy cell leukemia, and wherein the method further comprises
administering veltuzumab.
47. The method of claim 25, wherein the chelating agent is selected
from the group consisting of NOTA, DOTA, TETA.
48. The method of claim 30, wherein the chelating agent is selected
from the group consisting of NOTA, DOTA, TETA.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/774,526, filed Feb. 22, 2013, which was a divisional of
U.S. patent application Ser. No. 13/213,245 (now issued U.S. Pat.
No. 8,420,086), filed Aug. 19, 2011, which claimed the benefit
under 35 U.S.C. 119(e) of provisional U.S. Patent Appl. Ser. No.
61/375,068, filed Aug. 19, 2010. U.S. patent application Ser. No.
13/213,245 was a continuation-in-part of U.S. patent application
Ser. No. 13/164,275 (now issued U.S. Pat. No. 8,080,250), filed
Jun. 20, 2011; which was a divisional of U.S. patent application
Ser. No. 12/629,404 (now issued U.S. Pat. No. 7,999,083), filed
Dec. 2, 2009; which was a continuation-in-part of U.S. patent
application. Ser. No. 12/026,811 (now issued U.S. Pat. No.
7,591,994), filed Feb. 6, 2008; which was a continuation-in-part of
U.S. patent application Ser. No. 11/388,032, filed Mar. 23, 2006;
which was a continuation-in-part of U.S. patent application Ser.
No. 10/734,589 (now issued U.S. Pat. No. 7,585,491), filed Dec. 15,
2003. Those applications claimed the benefit under 35 U.S.C. 119(e)
of U.S. Provisional Patent Appl. Ser. Nos. 61/207,890, filed Feb.
13, 2009; 60/751,196, filed Dec. 16, 2005; 60/728,292, filed Oct.
19, 2005; 60/668,603, filed Apr. 6, 2005 and 60/433,017, filed Dec.
13, 2002. The text of each priority application is incorporated
herein by reference in its entirety.
SEQUENCE LISTING
[0002] The instant application contains a Sequence Listing which
has been submitted in ASCII format via EPS-Web and is hereby
incorporated by reference in its entirety. Said ASCII copy, created
on Aug. 18, 2011, is named IMM317US.txt and is 59,124 bytes in
size.
FIELD OF THE INVENTION
[0003] The present invention concerns compositions and methods of
use of immunoconjugates, comprising one or more camptothecin
moieties attached to an anti-CD22 antibody or antigen-binding
fragment thereof. Preferably, the anti-CD22 antibody is epratuzumab
and the camptothecin is SN-38. The immunoconjugate is of use to
treat B cell diseases, such as hematologic tumors, B cell leukemia
or lymphoma (e.g., mantle cell lymphoma, multiple myeloma,
Hodgkin's lymphoma, non-Hodgkin's lymphoma, diffuse large B cell
lymphoma, Burkitt lymphoma, follicular lymphoma, acute lymphocytic
leukemia, chronic lymphocytic leukemia, and hairy cell leukemia),
autoimmune disease, immune dysfunction disease and type 1 or type 2
diabetes. The immunoconjugate may be used alone or may be combined
with another anti-B cell antibody or fragment thereof, such as
antibodies against CD19, CD20. CD21, CD23, CD37, CD40, CD40L, CD52,
CD80 or HLA-DR. Alternatively, the immunoconjugate may be used in
combination with another therapeutic agent, such as an
immunomodulator, a cytotoxic agent, a drug, a toxin, an
anti-angiogenic agent, a proapoptotic agent or a radionuclide. The
anti-CD22 immunoconjugate may also be administered as part of a
dock-and-lock (DNL) complex, as described in detail below. In most
preferred embodiments, the combination of anti-CD22 antibody and
other therapeutic agent is significantly more efficacious for
treating a B cell disease than either agent administered alone or
the sum of effects of the agents administered separately.
BACKGROUND
[0004] An aim of targeted drug therapy is to use monoclonal
antibodies (MAbs) for the specific delivery of toxic agents to
human cancers. Conjugates of tumor-associated MAbs and suitable
toxic agents have been developed, but have had mixed success in the
therapy of cancer, and virtually no application in other diseases,
such as autoimmune diseases. The toxic agent is most commonly a
chemotherapeutic drug, although particle-emitting radionuclides, or
bacterial or plant toxins have also been conjugated to MAbs,
especially for the therapy of cancer (Sharkey and Goldenberg, CA
Cancer J Clin. 2006 July-August; 56(4):226-243).
[0005] The advantages of using MAb-chemotherapeutic drug conjugates
are that (a) the chemotherapeutic drug itself is structurally well
defined; (b) the chemotherapeutic drug is linked to the MAb protein
using very well defined conjugation chemistries, often at specific
sites remote from the MAb antigen binding regions; (c)
MAb-chemotherapeutic drug conjugates can be made more reproducibly
than chemical conjugates involving MAbs and bacterial or plant
toxins, and as such are more amenable to commercial development and
regulatory approval; and (d) the MAb-chemotherapeutic drug
conjugates are orders of magnitude less toxic systemically than
radionuclide MAb conjugates.
[0006] Early work on protein-drug conjugates indicated that a drug
preferably is released in its original form, once it has been
internalized into a target cell, for the protein-chemotherapeutic
drug conjugate to be a useful therapeutic. Trouet et al. (Proc.
Natl. Acad. Sci. USA 79:626-629 (1982)) showed the advantage of
using specific peptide linkers, between the drug and the antibody,
which are cleaved lysosomally to liberate the intact drug.
MAb-chemotherapeutic drug conjugates prepared using mild
acid-cleavable linkers, such as those containing a hydrazone, were
developed, based on the observation that the pH inside tumors was
often lower than normal physiological pH (Willner et al., U.S. Pat.
No. 5,708,146; Trail et al. (Science 261:212-215 (1993)). The first
approved MAb-drug conjugate, Gemtuzumab Ozogamicin, incorporated a
similar acid-labile hydrazone bond between an anti-CD33 antibody,
humanized P67.6, and a potent calicheamicin derivative. Sievers et
al., J Clin Oncol. 19:3244-3254 (2001); Hamann et al., Bioconjugate
Chem. 13: 47-58 (2002). In some cases, the MAb-chemotherapeutic
drug conjugates were made with reductively labile hindered
disulfide bonds between the chemotherapeutic drugs and the MAb (Liu
et al., Proc Natl Acad Sci USA 93: 8618-8623 (1996)).
[0007] Yet another cleavable linker involves cathepsin B-labile
dipeptide spacers, such as Phe-Lys or Val-Cit, similar to the
lysosomally labile peptide spacers of Trouet et al. containing from
one to four amino acids, which additionally incorporated a
collapsible spacer between the drug and the dipeptide (Dubowchik,
et al., Bioconjugate Chem. 13:855-869 (2002); Firestone et al.,
U.S. Pat. No. 6,214,345 B1; Doronina et al., Nat Biotechnol. 21:
778-784 (2003)). The latter approaches were also utilized in the
preparation of an immunoconjugate of camptothecin (Walker et al.,
Bioorg Med Chem Lett. 12:217-219 (2002)). Another cleavable moiety
that has been explored is an ester linkage incorporated into the
linker between the antibody and the chemotherapeutic drug.
Gillimard and Saragovi have found that when an ester of paclitaxel
was conjugated to anti-rat p75 MAb, MC 192, or anti-human TrkA MAb,
5C3, the conjugate was found to exhibit target-specific toxicity.
Gillimard and Saragovi, Cancer Res. 61:694-699 (2001).
[0008] The conjugates of the instant invention possess greater
efficacy, in many cases, than unconjugated or "naked" antibodies or
antibody fragments, although such unconjugated targeting molecules
have been of use in specific situations. In cancer, for example,
naked antibodies have come to play a role in the treatment of
lymphomas (CAMPATH.RTM. and RITUXAN.RTM.), colorectal and other
cancers (ERBITUX.RTM. and AVASTIN.RTM.), breast cancer
(HERECEPTIN.RTM.), as well as a large number now in clinical
development (e.g., epratuzumab). In most of these cases, clinical
use has involved combining these naked, or unconjugated, antibodies
with other therapies, such as chemotherapy or radiation
therapy.
[0009] A variety of antibodies are also in use for the treatment of
autoimmune and other immune dysregulatory diseases, such as tumor
necrosis factor (TNF) and B-cell (RITUXAN.RTM.) antibodies in
arthritis, and are being investigated in other such diseases, such
as the B-cell antibodies, RITUXAN.RTM. and epratuzumab, in systemic
lupus erythematosus and Sjogren's syndrome, as well as juvenile
diabetes and multiple sclerosis. Naked antibodies are also being
studied in sepsis and septic shock, Alzheimer's disease, and
infectious diseases.
[0010] There is a need to develop more potent immunoconjugated
antibodies against B cell diseases, such as cancer, autoimmune
disease, immune dysfunction disease, type 1 and type 2 diabetes.
There is a further need to develop more effective antibody
conjugates with intracellularly cleavable linkers. In the case of
delivering drug/toxin or radionuclide conjugates, this can be
accomplished by direct antibody conjugation or by indirect methods,
referred to as pretargeting, where a bispecific antibody is used to
target to the lesion, while the therapeutic agent is secondarily
targeted by binding to one of the arms of the bispecific antibody
that has localized at the site of the diseased cell (Goldenberg et
al., J Clin Oncol. 2006 Feb. 10; 24(5):823-34; Goldenberg et al., J
Nucl Med. 2008 January; 49(1):158-63).
[0011] Because signaling pathway redundancies can result in lack of
response to a single antibody, diverse strategies to use
combination therapy with antibodies that bind to different epitopes
or different antigens on the same target cell have been proposed.
Combinations such as anti-CD20 and anti-CD22 (Stein et al., Clin
Cancer Res 2004, 10:2868-2878), anti-CD20 and anti-HLA-DR (Tobin et
al., Leuk Lymphoma 2007, 48:944-956), anti-CD20 and anti-TRAIL-R1
(Maddipatla et al., Clin Cancer Res 2007, 13:4556-4564),
anti-IGF-1R and anti-EGFR (Goetsche et al., Int J Cancer 2005,
113:316-328), anti-IGF-1R and anti-VEGF (Shang et al., Mol Cancer
Ther 2008, 7:2599-2608), or trastuzumab and pertuzumab that target
different regions of human EGFR2 (Nahta et al., Cancer Res 2004,
64:2343-2346) have been evaluated preclinically, showing enhanced
or synergistic antitumor activity in vitro and in vivo.
[0012] The first clinical evidence of an apparent advantage of
combining two antibodies against different cancer cell antigens
involved the administration of rituximab (chimeric anti-CD20) and
epratuzumab (humanized anti-CD22 antibody) in patients with
non-Hodgkin lymphoma (NEHL). The combination was found to enhance
anti-lymphoma efficacy without a commensurate increase in toxicity,
based on 3 independent clinical trials (Leonard et al., J Clin
Oncol 2005, 23:5044-5051). Although these results are promising, a
need exists in the field for more effective antibody-based
combination therapies.
SUMMARY
[0013] The present invention concerns compositions and methods of
use of combination therapy with at least one anti-CD22 antibody or
fragment thereof and one or more therapeutic agents. The
therapeutic agent may be selected from the group consisting of an
immunomodulator, a cytotoxic agent, a drug, a toxin, an
anti-angiogenic agent, a proapoptotic agent, a radionuclide a
second antibody or fragment thereof, an siRNA or other inhibitory
oligonucleotide or any other known therapeutic agent. Preferably,
the therapeutic agent is conjugated to the anti-CD22 antibody or
fragment thereof to form an immunoconjugate. However, one or more
additional therapeutic agents, such as a second antibody or
fragment thereof, may also be separately administered, either
before, simultaneously with or after the immunoconjugate. In most
preferred embodiments, the one or more therapeutic agents may
comprise a camptothecin, such as SN-38.
[0014] Although camptothecin (CPT) and its analogs and derivatives
are preferred chemotherapeutic moieties, other chemotherapeutic
agents of use may include taxanes (e.g., baccatin III, paclitaxel),
epothilones, anthracycline drugs (e.g., doxorubicin, epirubicin,
morpholinodoxorubicin, cyanomorpholino-doxorubicin,
2-pyrrolinodoxorubicin, see Priebe W (ed.), ACS symposium series
574, American Chemical Society, Washington D.C., 1995; Nagy et al.,
Proc. Natl. Acad. Sci. USA 93:2464-2469, 1996), benzoquinoid
ansamycins exemplified by geldanamycin (DeBoer et al., Journal of
Antibiotics 23:442-447, 1970; Neckers et al., Invest. New Drugs
17:361-373, 1999), and the like. Preferably, the antibody is
conjugated to at least one chemotherapeutic moiety; preferably 1 to
about 5 chemotherapeutic moieties; most preferably about 6 to 12
chemotherapeutic moieties.
[0015] With regard to the CPT group of drugs, issues of
insolubility in aqueous buffers and the lability of the
.delta.-lactone moiety of the E-ring of their structures under
physiological conditions are relevant. One approach has been to
acylate the 20-hydroxyl group with an amino acid, and couple the
.alpha.-amino group of the amino acid to poly-L-glutamic acid
(Singer et al. in The Camptothecins: Unfolding Their Anticancer
Potential, Liehr J. G., Giovanella, B. C. and Verschraegen (eds),
NY Acad Sci., NY 922:136-150, 2000). This approach relies on the
passive diffusion of a polymeric molecule into tumor sites. This
glycine conjugation has also been reported as a method of making a
water-soluble derivative of CPT (Vishnuvajjala et al., U.S. Pat.
No. 4,943,579) and in the preparation of a PEG-derivatized CPT
(Greenwald, et al. J. Med. Chem. 39: 1938-1940, 1996). In the
latter case, the approach has been devised in the context of
developing water-soluble and long acting forms of CPT, whereby
CPT's in viva half-life is enhanced, and the drug is gradually
released from its conjugate while in circulation in viva. An
example of a water soluble CPT derivative is CPT-11. Extensive
clinical data are available concerning CPT-1 l's pharmacology and
its in viva conversion to the active SN-38 (Iyer and Ratain, Cancer
Chemother Pharmacol. 42:S31-43, 1998; Mathijssen et al., Clin
Cancer Res. 7:2182-2194, 2002; Rivory, Ann NY Acad Sci.
922:205-215, 2000). The active form SN-38 is about 2 to 3 orders of
magnitude more potent than CPT-11.
[0016] In one embodiment, the invention relates to a process of
preparing immunoconjugates, wherein a drug is derivatized with a
first linker, which contains a reactive moiety that is capable of
combining with a second linker that contains an antibody-coupling
group; wherein the first linker also possesses a defined
polyethylene glycol (PEG) moiety for water-solubility, and
optionally an intracellularly-cleavable moiety cleavable by
intracellular peptidases or by the low pH environment of endosomal
and lysosomal vesicles. Also optionally there is an amino acid
spacer between the drug and the first linker. The second linker may
also contain a reactive group capable of reacting with drug-(first
linker) conjugate by the copper (+1) ion-catalyzed acetylene-azide
cycloaddition reaction, referred to as `click chemistry`.
Preferably, the defined PEG moiety is a low molecular weight PEG
with a defined number of monomeric subunits, as discussed
below.
[0017] Another embodiment relates to a process of preparing
conjugates as discussed in the paragraph above, wherein the second
linker has a single antibody-coupling group, but multiples of the
reactive group capable of reacting with drug-(first linker)
conjugate, thereby amplifying the number of drug molecules
conjugated to the antibody.
[0018] A further embodiment relates to a process of preparing
conjugates, wherein the linker is first conjugated to a drug,
thereby producing a drug-linker conjugate; wherein said drug-linker
conjugate preparation involves the selective protection and
deprotection of a more reactive group in a drug containing multiple
functional groups; wherein said drug-linker conjugate is optionally
not purified; and wherein said drug-linker conjugate is
subsequently conjugated to a monoclonal antibody or fragment.
[0019] In one embodiment, the intracellularly-cleavable moiety is a
carbonate comprising an activated hydroxyl group of the
chemotherapeutic moiety and a substituted ethanolamine moiety or a
4-aminobenzyl alcohol, and the latter is attached, via its amino
group, to a cross-linker terminating in the antibody-binding group;
and wherein the substituted ethanolamine moiety is derived from a
natural L amino acid, with the carboxylic acid group of the latter
replaced with a hydroxymethyl moiety; and wherein the 4-aminobenzyl
alcohol is optionally substituted with a C.sub.1-C.sub.10 alkyl
group at the benzylic position.
[0020] In a preferred embodiment, the intracellularly-cleavable
moiety is a carbonate comprising an activated hydroxyl group of the
chemotherapeutic moiety and a substituted ethanolamine moiety, and
the latter, via its amino group, is attached to an L-amino acid or
a polypeptide comprising up to four L-amino acid moieties; wherein
the N-terminus is attached to a cross-linker terminating in the
antibody-binding group; and wherein the substituted ethanolamine
moiety is optionally derived from an L amino acid, with the
carboxylic acid group of the latter replaced with a hydroxymethyl
moiety.
[0021] In another preferred embodiment, the
intracellularly-cleavable moiety is a carbonate comprising an
activated hydroxyl group of the chemotherapeutic moiety and a
4-aminobenzyl alcohol or substituted 4-aminobenzyl alcohol
substituted with a C.sub.1-C.sub.10 alkyl group at the benzylic
position, and the latter, via its amino group, is attached to an
L-amino acid or a polypeptide comprising up to four L-amino acid
moieties; wherein the N-terminus is attached to a cross-linker
terminating in the antibody-binding group.
[0022] In certain embodiments, an amino group of a chemotherapeutic
moiety is coupled to the activated hydroxyl group of a substituted,
and amine-protected, ethanolamine moiety or a 4-aminobenzyl
alcohol, and the latter is attached, via its amino group, to an
L-amino acid or a polypeptide comprising up to four L-amino acid
moieties; wherein the N-terminus is attached to a cross-linker
terminating in the antibody-binding group; wherein said substituted
ethanolamine moiety is optionally derived from an L amino acid,
with the carboxylic acid group of the latter replaced with a
hydroxymethyl moiety; and wherein the 4-aminobenzyl alcohol is
optionally substituted with a C.sub.1-C.sub.10 alkyl group at the
benzylic position. The bifunctional drug derivative is then
conjugated to an antibody to obtain an immunoconjugate as discussed
above. Upon targeting the disease site with the immunoconjugate,
the immunoconjugate is endocytosed and catabolized to release the
drug-linker moiety; wherein the free amino group of the substituted
ethanolamine moiety assists in the liberation of free drug by
nucleophilic attack at the carbonyl group of the carbamate
moiety.
[0023] In certain embodiments, the anti-CD22 antibody or fragment
thereof is administered as part of a trivalent, tetravalent or
hexavalent construct made by the dock-and-lock (DNL) technique
(see, e.g., U.S. Pat. Nos. 7,521,056; 7,527,787; 7,534,866;
7,550,143; 7,666,400; 7,858,070; 7,871,622; 7,901,680; 7,906,118
and 7,906,121, the Examples section of each of which is
incorporated herein by reference.) The DNL technique takes
advantage of the specific, high-affinity binding interaction
between a dimerization and docking domain (DDD) sequence from the
regulatory subunit of human cAMP-dependent protein kinase (PKA),
such as human PKA RI.alpha., RI.beta., RII.alpha. or RII.beta., and
an anchor domain (AD) sequence from any of a variety of AKAP
proteins. The DDD and AD peptides may be attached to any protein,
peptide or other molecule.
[0024] Because the DDD sequences spontaneously dimerize and bind to
the AD sequence, the DNL technique allows the formation of
complexes between any selected molecules that may be attached to
DDD or AD sequences. Although the standard DNL complex comprises a
trimer with two DDD-linked molecules attached to one AD-linked
molecule, variations in complex structure allow the formation of
dimers, trimers, tetramers, pentamers, hexamers and other
multimers. In some embodiments, the DNL complex may comprise two or
more antibodies, antibody fragments or fusion proteins which bind
to the same antigenic determinant or to two or more different
antigens. The DNL complex may also comprise one or more other
effectors, such as a cytokine, toxin or PEG moiety.
[0025] Many examples of anti-CD22 antibodies are also known in the
art and any such known antibody or fragment thereof may be
utilized. In a preferred embodiment, the anti-CD22 antibody is an
hLL2 antibody (also known as epratuzumab) that comprises the light
chain CDR sequences CDR1 (KSSQSVLYSANHKYLA, SEQ ID NO:1), CDR2
(WASTRES, SEQ ID NO:2), and CDR3 (HQYLSSWTF, SEQ ID NO:3) and the
heavy chain CDR sequences CDR1 (SYWLH, SEQ ID NO:4), CDR2
(YINPRNDYTEYNQNFKD, SEQ ID NO:5), and CDR3 (RDITTFY, SEQ ID NO:6).
A humanized LL2 anti-CD22 antibody suitable for use is disclosed in
U.S. Pat. No. 6,187,287, incorporated herein by reference from Col.
11, line 40 through Col. 20, line 38 and FIG. 1, 4 and 5. However,
in alternative embodiments, other known and/or commercially
available anti-CD22 antibodies may be utilized, such as 1F5; HIB22
(ABBIOTEC.RTM., San Diego, Calif.); FPC1, LT22, MEM-1, RFB4
(ABCAM.RTM., Cambridge, Mass.); bu59, fpc1, mc64-12 (ABD
SEROTEC.RTM., Raleigh, N.C.); IS7 (ABNOVA.RTM., Taipei City,
Taiwan) and any other anti-CD22 antibody known in the art.
[0026] The anti-CD22 antibody may be selected such that it competes
with or blocks binding to CD22 of an LL2 antibody comprising the
light chain CDR sequences CDR1 (KSSQSVLYSANHKYLA, SEQ ID NO: 1),
CDR2 (WASTRES, SEQ ID NO:2), and CDR3 (HQYLSSWTF, SEQ ID NO:3) and
the heavy chain CDR sequences CDR1 (SYWLH, SEQ ID NO:4), CDR2
(YINPRNDYTEYNQNFKD, SEQ ID NO:5), and CDR3 (RDITTFY, SEQ ID NO:6).
Alternatively, the anti-CD22 antibody may bind to the same epitope
of CD22 as an LL2 antibody.
[0027] The anti-CD22 antibody may optionally be administered in
combination with an anti-CD20 antibody or fragment thereof. Many
examples of anti-CD20 antibodies are known in the art and any such
known antibody or fragment thereof may be utilized. In a preferred
embodiment, the anti-CD20 antibody is an hA20 antibody (also known
as veltuzumab) that comprises the light chain
complementarity-determining region (CDR) sequences CDR1
(RASSSVSYIH; SEQ ID NO:7), CDR2 (ATSNLAS; SEQ ID NO:8), and CDR3
(QQWTSNPPT; SEQ ID NO:9) and the heavy chain variable region CDR
sequences CDR1 (SYNMH; SEQ ID NO:10), CDR2 (AIYPGNGDTSYNQKFKG; SEQ
ID NO: 11), and CDR3 (STYYGGDWYFDV; SEQ ID NO:12).
[0028] A humanized anti-CD20 antibody suitable for use is disclosed
in U.S. Pat. No. 7,435,803, incorporated herein by reference from
Col. 36, line 4 through Col. 46, line 52 and FIGS. 1, 2, 4, 5 and
7. However, in alternative embodiments, other known and/or
commercially available anti-CD20 antibodies may be utilized, such
as rituximab; ofatumumab; ibritumomab; tositumomab; ocrelizumab;
GA101; BCX-301; DXL 625; L26, B-Ly1, MEM-97, LT20, 2H7, AT80, B-H20
(ABCAM.RTM., Cambridge, Mass.); HI20a, HI47, 13.6E12
(ABBIOTEC.RTM., San Diego, Calif.); 4f11, 5c11, 7d1 (ABD
SEROTEC.RTM., Raleigh, N.C.) and any other anti-CD20 antibody known
in the art.
[0029] The anti-CD20 antibody may be selected such that it competes
with or blocks binding to CD20 of an hA20 antibody comprising the
light chain complementarity-determining region (CDR) sequences CDR1
(RASSSVSYIH; SEQ ID NO:7), CDR2 (ATSNLAS; SEQ ID NO:8), and CDR3
(QQWTSNPPT; SEQ ID NO:9) and the heavy chain variable region CDR
sequences CDR1 (SYNMH; SEQ ID NO:10), CDR2 (AIYPGNGDTSYNQKFKG; SEQ
ID NO: 11), and CDR3 (STYYGGDWYFDV; SEQ ID NO:12). Alternatively,
the anti-CD20 antibody may bind to the same epitope of CD20 as a
hA20 antibody.
[0030] The anti-CD22 antibody may be conjugated to or separately
administered with one or more therapeutic agents. The therapeutic
agent may be selected from the group consisting of aplidin,
azaribine, anastrozole, azacytidine, bleomycin, bortezomib,
bryostatin-1, busulfan, calicheamycin, camptothecin,
10-hydroxycamptothecin, carmustine, celebrex, chlorambucil,
cisplatin, irinotecan (CPT-11), SN-38, carboplatin, cladribine,
cyclophosphamide, cytarabine, dacarbazine, docetaxel, dactinomycin,
daunomycin glucuronide, daunorubicin, dexamethasone,
diethylstilbestrol, doxorubicin, doxorubicin glucuronide,
epirubicin glucuronide, ethinyl estradiol, estramustine, etoposide,
etoposide glucuronide, etoposide phosphate, floxuridine (FUdR),
3',5'-O-dioleoyl-FudR (FUdR-dO), fludarabine, flutamide,
fluorouracil, fluoxymesterone, gemcitabine, hydroxyprogesterone
caproate, hydroxyurea, idarubicin, ifosfamide, L-asparaginase,
leucovorin, lomustine, mechlorethamine, medroprogesterone acetate,
megestrol acetate, melphalan, mercaptopurine, 6-mercaptopurine,
methotrexate, mitoxantrone, mithramycin, mitomycin, mitotane,
phenyl butyrate, prednisone, procarbazine, paclitaxel, pentostatin,
PSI-341, semustine streptozocin, tamoxifen, taxanes, taxol,
testosterone propionate, thalidomide, thioguanine, thiotepa,
teniposide, topotecan, uracil mustard, velcade, vinblastine,
vinorelbine, vincristine, ricin, abrin, ribonuclease, onconase,
rapLR1, DNase I, Staphylococcal enterotoxin-A, pokeweed antiviral
protein, gelonin, diphtheria toxin, Pseudomonas exotoxin, and
Pseudomonas endotoxin.
[0031] The therapeutic agent may comprise a radionuclide selected
from the group consisting of .sup.103mRh, .sup.103Ru, .sup.105Rh,
.sup.105Ru, .sup.107Hg, .sup.109Pd, .sup.109Pt, .sup.111Ag,
.sup.111In, .sup.113mIn, .sup.119Sb, .sup.11C, .sup.121mTe,
.sup.122mTe, .sup.125I, .sup.125mTe, .sup.126I, .sup.131I,
.sup.133I, .sup.13N, .sup.142Pr, .sup.143Pr, .sup.149Pm,
.sup.152Dy, .sup.153Sm, .sup.15O, .sup.161Ho, .sup.161Tb,
.sup.165Tm, .sup.166Dy, .sup.166Ho, .sup.167Tm, .sup.168Tm,
.sup.169Er, .sup.169Yb, .sup.177Lu, .sup.186Re, .sup.188Re,
.sup.189mOs, .sup.189Re, .sup.192Ir, .sup.194Ir, .sup.197Pt,
.sup.198Au, .sup.199Au, .sup.201Tl, .sup.203Hg, .sup.211At,
.sup.211Bi, .sup.211Pb, .sup.212Bi, .sup.212Pb, .sup.213Bi,
.sup.215Po, .sup.217At, .sup.219Rn, .sup.221Fr, .sup.223Ra,
.sup.224Ac, .sup.225Ac, .sup.225Fm, .sup.32P, .sup.33P, .sup.47Sc,
.sup.51Cr, .sup.57Co, .sup.58Co, .sup.59Fe, .sup.62Cu, .sup.67Cu,
.sup.67Ga, .sup.75Br, .sup.75Se, .sup.76Br, .sup.77As, .sup.77Br,
.sup.80mBr, .sup.89Sr, .sup.90Y, .sup.95Ru, .sup.97Ru, .sup.99Mo
and .sup.99mTc.
[0032] The therapeutic agent may be an enzyme selected from the
group consisting of malate dehydrogenase, staphylococcal nuclease,
delta-V-steroid isomerase, yeast alcohol dehydrogenase,
alpha-glycerophosphate dehydrogenase, triose phosphate isomerase,
horseradish peroxidase, alkaline phosphatase, asparaginase, glucose
oxidase, beta-galactosidase, ribonuclease, urease, catalase,
glucose-6-phosphate dehydrogenase, glucoamylase and
acetylcholinesterase.
[0033] The therapeutic agent may be an immunomodulator selected
from the group consisting of a cytokine, a stem cell growth factor,
a lymphotoxin, a hematopoietic factor, a colony stimulating factor
(CSF), an interferon (IFN), erythropoietin, thrombopoietin and
combinations thereof. Exemplary immunomodulators may include IL-1,
IL-2, IL-3, IL-6, IL-10, IL-12, IL-18, IL-21, interferon-.alpha.,
interferon-.beta., interferon-.gamma., G-CSF, GM-CSF, and mixtures
thereof.
[0034] Alternatively, the therapeutic agent may be an
anti-angiogenic agent selected from the group consisting of
angiostatin, endostatin, baculostatin, canstatin, maspin, anti-VEGF
binding molecules, anti-placental growth factor binding molecules
and anti-vascular growth factor binding molecules.
[0035] In certain embodiments, the anti-CD22 antibody or fragment
may comprise one or more chelating moieties, such as NOTA, DOTA,
DTPA, TETA, Tscg-Cys, or Tsca-Cys. In certain embodiments, the
chelating moiety may form a complex with a therapeutic or
diagnostic cation, such as Group II, Group III, Group IV, Group V,
transition, lanthanide or actinide metal cations, Tc, Re, Bi, Cu,
As, Ag, Au, At, or Pb.
[0036] In some embodiments, the anti-CD22 antibody or fragment
thereof may be a human, chimeric, or humanized antibody or fragment
thereof. A humanized antibody or fragment thereof may comprise the
complementarity-determining regions (CDRs) of a murine antibody and
the constant and framework (FR) region sequences of a human
antibody, which may be substituted with at least one amino acid
from corresponding FRs of a murine antibody. A chimeric antibody or
fragment thereof may include the light and heavy chain variable
regions of a murine antibody, attached to human antibody constant
regions. The antibody or fragment thereof may include human
constant regions of IgG1, IgG2a, IgG3, or IgG4.
[0037] Exemplary known antibodies of use include, but are not
limited to, hR1 (anti-IGF-1R), hPAM4 (anti-mucin), hA20
(anti-CD20), hA19 (anti-CD19), hIMMU31 (anti-AFP), hLL1
(anti-CD74), hLL2 (anti-CD22), hMu-9 (anti-CSAp), hL243
(anti-HLA-DR), hMN-14 (anti-CEACAM5), hMN-15 (anti-CEACAM6), 29H2
(anti-CEACAM1, ABCAM.RTM.), hRS7 (anti-EGP-1) and hMN-3
(anti-CEACAM6).
[0038] In alternative embodiments, antibodies or fragments of use
may bind to one or more target antigens selected from the group
consisting of carbonic anhydrase IX, alpha-fetoprotein,
.alpha.-actinin-4, A3, antigen specific for A33 antibody, ART-4,
B7, Ba 733, BAGE, BrE3-antigen, CA125, CAMEL, CAP-1, CASP-8/m,
CCCL19, CCCL21, CD1, CD1a, CD2, CD3, CD4, CD5, CD8, CD11A, CD14,
CD15, CD16, CD18, CD19, CD20, CD21, CD22, CD23, CD25, CD29, CD30,
CD32b, CD33, CD37, CD38, CD40, CD40L, CD45, CD46, CD52, CD54, CD55,
CD59, CD64, CD66a-e, CD67, CD70, CD74, CD79a, CD80, CD83, CD95,
CD126, CD132, CD133, CD138, CD147, CD154, CDC27, CDK-4/m, CDKN2A,
CXCR4, colon-specific antigen-p (CSAp), CEA (CEACAM5), CEACAM1,
CEACAM6, c-met, DAM, EGFR, EGFRvIII, EGP-1, EGP-2, ELF2-M, Ep-CAM,
Flt-1, Flt-3, folate receptor, G250 antigen, GAGE, gp100, GROB,
HLA-DR, HM1.24, human chorionic gonadotropin (HCG) and its
subunits, HER2/neu, HMGB-1, hypoxia inducible factor (HIF-1),
HSP70-2M, HST-2, Ia, IGF-1R, IFN-.gamma., IFN-.alpha., IFN-.beta.,
IL-2, IL-4R, IL-6R, IL-13R, IL-15R, IL-17R, IL-18R, IL-6, IL-8,
IL-12, IL-15, IL-17, IL-18, IL-23, IL-25, insulin-like growth
factor-1 (IGF-1), KC4-antigen, KS-1-antigen, KS1-4, Le-Y, LDR/FUT,
macrophage migration inhibitory factor (MIF), MAGE, MAGE-3, MART-1,
MART-2, NY-ESO-1, TRAG-3, mCRP, MCP-1, MIP-1A, MIP-1B, MIF, MUC1,
MUC2, MUC3, MUC4, MUC5, MUM-1/2, MUM-3, NCA66, NCA95, NCA90,
antigen specific for PAM-4 antibody, placental growth factor, p53,
PLAGL2, prostatic acid phosphatase, PSA, PRAME, PSMA, PIGF, IGF,
IGF-1R, IL-6, RS5, RANTES, T101, SAGE, S100, survivin, survivin-2B,
TAC, TAG-72, tenascin, TRAIL receptors, TNF-.alpha., Tn antigen,
Thomson-Friedenreich antigens, tumor necrosis antigens, VEGFR, ED-B
fibronectin, WT-1, 17-1A-antigen, complement factors C3, C3a, C3b,
C5a, C5, an angiogenesis marker, bcl-2, bcl-6, Kras, cMET, an
oncogene marker and an oncogene product (see, e.g., Sensi et al.,
Clin Cancer Res 2006, 12:5023-32; Parmiani et al., J Immunol 2007,
178:1975-79; Novellino et al. Cancer Immunol Immunother 2005,
54:187-207). Reports on tumor associated antigens include Mizukami
et al., (2005, Nature Med. 11:992-97); Hatfield et al., (2005,
Curr. Cancer Drug Targets 5:229-48); Vallbohmer et al. (2005, J.
Clin. Oncol. 23:3536-44); and Ren et al. (2005, Ann. Surg.
242:55-63).
[0039] Also disclosed is a method for treating and/or diagnosing a
disease or disorder that includes administering to a patient a
therapeutic and/or diagnostic composition that includes any of the
aforementioned antibodies or immunoconjugates or fragments thereof.
Typically, the composition is administered to the patient
intravenously, intramuscularly or subcutaneously at a dose of
20-5000 mg. In preferred embodiments, the disease or disorder is a
B-cell lymphoma or leukemia, an immune dysregulation disease, an
autoimmune disease, organ-graft rejection or graft-versus-host
disease. More preferably, the disease is a B-cell lymphoma or
leukemia. Exemplary malignancies that may be treated using the
claimed methods and compositions include, but are not limited to,
indolent forms of B-cell lymphomas, aggressive forms of B-cell
lymphomas, acute lymphocytic leukemia, chronic lymphocytic
leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma, mantle cell
lymphoma, diffuse large B-cell lymphoma, follicular lymphoma,
marginal zone lymphoma, Burkitt's lymphoma and multiple myeloma
[0040] Exemplary autoimmune diseases include acute immune
thrombocytopenia, chronic immune thrombocytopenia, dermatomyositis,
Sydenham's chorea, myasthenia gravis, systemic lupus erythematosus,
lupus nephritis, rheumatic fever, polyglandular syndromes, bullous
pemphigoid, pemphigus vulgaris, diabetes mellitus (e.g., juvenile
diabetes), Henoch-Schonlein purpura, post-streptococcal nephritis,
erythema nodosum, Takayasu's arteritis, Addison's disease,
rheumatoid arthritis, multiple sclerosis, sarcoidosis, ulcerative
colitis, erythema multiforme, IgA nephropathy, polyarteritis
nodosa, ankylosing spondylitis, Goodpasture's syndrome,
thromboangitis obliterans, Sjogren's syndrome, primary biliary
cirrhosis, Hashimoto's thyroiditis, thyrotoxicosis, scleroderma,
chronic active hepatitis, polymyositis/dermatomyositis,
polychondritis, pemphigus vulgaris, Wegener's granulomatosis,
membranous nephropathy, amyotrophic lateral sclerosis, tabes
dorsalis, giant cell arteritis/polymyalgia, pernicious anemia,
rapidly progressive glomerulonephritis, psoriasis, or fibrosing
alveolitis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The following Figures are provided to illustrate exemplary,
but non-limiting, preferred embodiments of the invention.
[0042] FIG. 1. Preclinical in vivo therapy of athymic nude mice,
bearing Capan 1 human pancreatic carcinoma, with MAb-CL2A-SN-38
conjugates.
[0043] FIG. 2. Preclinical in vivo therapy of athymic nude mice,
bearing BxPC3 human pancreatic carcinoma, with MAb-CL2A-SN-38
conjugates.
[0044] FIG. 3. Preclinical in vivo therapy of athymic nude mice,
bearing LS174T human colon carcinoma, with hMN-14-CL2A-SN-38
conjugate.
[0045] FIG. 4. Epratuzumab-SN-38 in combination with veltuzumab for
treatment of follicular B cell lymphoma (WSU-FSCCL) (Experiment
A).
[0046] FIG. 5. Epratuzumab-SN-38 in combination with veltuzumab for
treatment of follicular B cell lymphoma (WSU-FSCCL) (Experiment
B).
[0047] FIG. 6. Epratuzumab-SN-38 used alone for treatment of 697
cell line (ALL).
[0048] FIG. 7. Dose-response data for epratuzumab-CL2A-SN38 vs.
control MAb-CL2A-SN38 for SC Ramos lymphoma in nude mice.
DETAILED DESCRIPTION
Definitions
[0049] As used herein, the terms "a", "an" and "the" may refer to
either the singular or plural, unless the context otherwise makes
clear that only the singular is meant.
[0050] An "antibody" refers to a full-length (i.e., naturally
occurring or formed by normal immunoglobulin gene fragment
recombinatorial processes) immunoglobulin molecule (e.g., an IgG
antibody) or an immunologically active (i.e., antigen-binding)
portion of an immunoglobulin molecule, like an antibody
fragment.
[0051] An "antibody fragment" is a portion of an antibody such as
F(ab').sub.2, F(ab).sub.2, Fab', Fab, Fv, scFv, single domain
antibodies (DABs or VHHs) and the like, including half-molecules of
IgG4 (van der Neut Kolfschoten et al. (Science 2007; 317(14
September): 1554-1557). Regardless of structure, an antibody
fragment binds with the same antigen that is recognized by the
intact antibody. For example, an anti-CD22 antibody fragment binds
with an epitope of CD22. The term "antibody fragment" also includes
isolated fragments consisting of the variable regions, such as the
"Fv" fragments consisting of the variable regions of the heavy and
light chains and recombinant single chain polypeptide molecules in
which light and heavy chain variable regions are connected by a
peptide linker ("scFv proteins"). As used herein, the term
"antibody fragment" does not include fragments such as Fc fragments
that do not contain antigen-binding sites.
[0052] A "chimeric antibody" is a recombinant protein that contains
the variable domains including the complementarity determining
regions (CDRs) of an antibody derived from one species, preferably
a rodent antibody, while the constant domains of the antibody
molecule are derived from those of a human antibody. For veterinary
applications, the constant domains of the chimeric antibody may be
derived from that of other species, such as a cat or dog.
[0053] A "humanized antibody" is a recombinant protein in which the
CDRs from an antibody from one species; e.g., a rodent antibody,
are transferred from the heavy and light variable chains of the
rodent antibody into human heavy and light variable domains.
Additional FR amino acid substitutions from the parent, e.g.
murine, antibody may be made. The constant domains of the antibody
molecule are derived from those of a human antibody.
[0054] A "human antibody" is, for example, an antibody obtained
from transgenic mice that have been genetically engineered to
produce human antibodies in response to antigenic challenge. In
this technique, elements of the human heavy and light chain locus
are introduced into strains of mice derived from embryonic stem
cell lines that contain targeted disruptions of the endogenous
heavy chain and light chain loci. The transgenic mice can
synthesize human antibodies specific for human antigens, and the
mice can be used to produce human antibody-secreting hybridomas.
Methods for obtaining human antibodies from transgenic mice are
described by Green et al., Nature Genet. 7:13 (0.1994), Lonberg et
al., Nature 368:856 (1994), and Taylor et al., Int. Immun. 6:579
(1994). A fully human antibody also can be constructed by genetic
or chromosomal transfection methods, as well as phage display
technology, all of which are known in the art. (See, e.g.,
McCafferty et al., Nature 348:552-553 (1990) for the production of
human antibodies and fragments thereof in vitro, from
immunoglobulin variable domain gene repertoires from unimmunized
donors). In this technique, antibody variable domain genes are
cloned in-frame into either a major or minor coat protein gene of a
filamentous bacteriophage, and displayed as functional antibody
fragments on the surface of the phage particle. Because the
filamentous particle contains a single-stranded DNA copy of the
phage genome, selections based on the functional properties of the
antibody also result in selection of the gene encoding the antibody
exhibiting those properties. In this way, the phage mimics some of
the properties of the B cell. Phage display can be performed in a
variety of formats, for their review, see, e.g. Johnson and
Chiswell, Current Opinion in Structural Biology 3:5564-571 (1993).
Human antibodies may also be generated by in vitro activated B
cells. (See, U.S. Pat. Nos. 5,567,610 and 5,229,275).
[0055] A "therapeutic agent" is an atom, molecule, or compound that
is useful in the treatment of a disease. Examples of therapeutic
agents include but are not limited to antibodies, antibody
fragments, drugs, toxins, enzymes, nucleases, hormones,
immunomodulators, antisense oligonucleotides, chelators, boron
compounds, photoactive agents, dyes and radioisotopes.
[0056] A "diagnostic agent" is an atom, molecule, or compound that
is useful in diagnosing a disease. Useful diagnostic agents
include, but are not limited to, radioisotopes, dyes, contrast
agents, fluorescent compounds or molecules and enhancing agents
(e.g., paramagnetic ions). Preferably, the diagnostic agents are
selected from the group consisting of radioisotopes, enhancing
agents, and fluorescent compounds.
[0057] An "immunoconjugate" is a conjugate of an antibody, antibody
fragment, antibody fusion protein, bispecific antibody or
multispecific antibody with an atom, molecule, or a higher-ordered
structure (e.g., with a carrier, a therapeutic agent, or a
diagnostic agent). A "naked antibody" is an antibody that is not
conjugated to any other agent.
[0058] As used herein, the term "antibody fusion protein" is a
recombinantly produced antigen-binding molecule in which an
antibody or antibody fragment is covalently linked to another
protein or peptide, such as the same or different antibody or
antibody fragment or a DDD or AD peptide. The fusion protein may
comprise a single antibody component, a multivalent or
multispecific combination of different antibody components or
multiple copies of the same antibody component. The fusion protein
may additionally comprise an antibody or an antibody fragment and a
therapeutic agent. Examples of therapeutic agents suitable for such
fusion proteins include immunomodulators and toxins. One preferred
toxin comprises a ribonuclease (RNase), preferably a recombinant
RNase.
[0059] A "multispecific antibody" is an antibody that can bind
simultaneously to at least two targets that are of different
structure, e.g., two different antigens, two different epitopes on
the same antigen, or a hapten and/or an antigen or epitope. A
"multivalent antibody" is an antibody that can bind simultaneously
to at least two targets that are of the same or different
structure. Valency indicates how many binding arms or sites the
antibody has to a single antigen or epitope; i.e., monovalent,
bivalent, trivalent or multivalent. The multivalency of the
antibody means that it can take advantage of multiple interactions
in binding to an antigen, thus increasing the avidity of binding to
the antigen. Specificity indicates how many antigens or epitopes an
antibody is able to bind; i.e., monospecific, bispecific,
trispecific, multispecific. Using these definitions, a natural
antibody, e.g., an IgG, is bivalent because it has two binding arms
but is monospecific because it binds to one epitope. Multispecific,
multivalent antibodies are constructs that have more than one
binding site of different specificity. For example, a diabody,
where one binding site reacts with one antigen and the other with
another antigen.
[0060] A "bispecific antibody" is an antibody that can bind
simultaneously to two targets which are of different structure.
[0061] As used herein, "CPT" is an abbreviation for camptothecin,
and represents camptothecin itself or an analog or derivative of
camptothecin. The structures of camptothecin and some of its
analogs, with the numbering indicated and the rings labeled with
letters A-E, are given in formula 1 in Chart 1 below.
##STR00001##
[0062] Camptothecin Immunoconjugates
[0063] Methods are devised in the following ways for the
preparation of immunoconjugates of chemotherapeutic drugs with
antibodies (MAbs). The disclosed methods represent a preferred
embodiment of the invention. (1) Solubility of the drug may be
enhanced by placing a defined polyethyleneglycol (PEG) moiety
(i.e., a PEG containing a defined number of monomeric units)
between the drug and the targeting vector, wherein the defined PEG
is a low molecular weight PEG, preferably containing 1-30 monomeric
units, more preferably containing 1-12 monomeric units. (2) A first
linker connects the drug at one end and terminates with an
acetylene or an azide group at the other end. This first linker
comprises a defined PEG moiety with an azide or acetylene group at
one end and a different reactive group, such as carboxylic acid or
hydroxyl group, at the other end. Said bifunctional defined PEG is
attached to the amine group of an amino alcohol, and the hydroxyl
group of the latter is attached to the hydroxyl group on the drug
in the form of a carbonate. Alternatively, the non-azide (or
acetylene) moiety of said defined bifunctional PEG is attached to
the N-terminus of an L-amino acid or a polypeptide, with the
C-terminus attached to the amino group of amino alcohol, and the
hydroxy group of the latter is attached to the hydroxyl group of
the drug in the form of carbonate or carbamate, respectively. (3) A
second linker, comprising an antibody-coupling group and a reactive
group complementary to the azide (or acetylene) group of the first
linker, namely acetylene (or azide), reacts with the drug-(first
linker) conjugate via acetylene-azide cycloaddition reaction to
furnish the final bifunctional drug product that is useful for
conjugating to the disease-targeting antibodies. (4) The
antibody-coupling group is designed to be either a thiol or a
thiol-reactive group. (5) Methods are devised for selective
regeneration of the 10-hydroxyl group in the presence of the C-20
carbonate in preparations of drug-linker precursor involving CPT
analogs such as SN-38. (6) Other protecting groups for reactive
hydroxyl groups in drugs such as the phenolic hydroxyl in SN-38,
for example, such as t-butyldimethylsilyl or t-butyldiphenylsilyl
are also used, and these are deprotected by tetrabutylammonium
fluoride prior to linking of the derivatized drug to a
targeting-vector-coupling moiety. (7) The 10-hydroxyl group of CPT
analogs is alternatively protected as an ester or carbonate, other
than `BOC`, such that the bifunctional CPT is conjugated to an
antibody without prior deprotection of this protecting group, and
the protecting group is readily deprotected under physiological pH
conditions after the bioconjugate is administered.
[0064] In the acetylene-azide coupling, referred to as `click
chemistry`, the azide part may be on L2 with the acetylene part on
L3. Alternatively, L2 may contain acetylene, with L3 containing
azide. `Click chemistry` is a copper (+1)-catalyzed cycloaddition
reaction between an acetylene moiety and an azide moiety, and is a
relatively recent technique in bioconjugation (Kolb H C and
Sharpless K B, Drug Discov Today 2003; 8: 1128-37). Alternative
methods of copper-free click chemistry are described below. Click
chemistry takes place in aqueous solution at near-neutral pH
conditions, and is thus amenable for drug conjugation. The
advantage of click chemistry is that it is chemoselective, and
complements other well-known conjugation chemistries such as the
thiol-maleimide reaction. In the following discussion, where a
conjugate comprises an antibody or antibody fragment, another type
of binding moiety, such as an aptamer, avimer or targeting peptide,
may be substituted.
[0065] An exemplary preferred embodiment is directed to a conjugate
of a drug derivative and an antibody of the general formula 2,
MAb-[L2]-[L1]-[AA].sub.m-[A']-Drug (2)
where MAb is a disease-targeting antibody, such as an anti-CD22
antibody; L2 is a component of the cross-linker comprising an
antibody-coupling moiety and one or more of acetylene (or azide)
groups; L1 comprises a defined PEG with azide (or acetylene) at one
end, complementary to the acetylene (or azide) moiety in L2, and a
reactive group such as carboxylic acid or hydroxyl group at the
other end; AA is an L-amino acid; m is an integer with values of 0,
1, 2, 3, or 4; and A' is an additional spacer, selected from the
group of ethanolamine, 4-hydroxybenzyl alcohol, 4-aminobenzyl
alcohol, or substituted or unsubstituted ethylenediamine. The L
amino acids of `AA` are selected from alanine, arginine,
asparagine, aspartic acid, cysteine, glutamine, glutamic acid,
glycine, histidine, isoleucine, leucine, lysine, methionine,
phenylalanine, proline, serine, threonine, tryptophan, tyrosine,
and valine. If the A' group contains a hydroxyl, it is linked to
the hydroxyl group or amino group of the drug in the form of a
carbonate or carbamate, respectively.
[0066] In a preferred embodiment of formula 2, A' is a substituted
ethanolamine derived from an L-amino acid, wherein the carboxylic
acid group of the amino acid is replaced by a hydroxymethyl moiety.
A' may be derived from any one of the following L-amino acids:
alanine, arginine, asparagine, aspartic acid, cysteine, glutamine,
glutamic acid, glycine, histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, proline, serine, threonine, tryptophan,
tyrosine, and valine.
[0067] In an example of the immunoconjugate of the preferred
embodiment of formula 2, m is 0, A' is L-valinol, and the drug is
exemplified by SN-38. The resultant structure is shown in formula
3.
##STR00002##
[0068] In another example of the immunoconjugate of the preferred
embodiment of formula 2, m is 1 and represented by a derivatized
L-lysine, A' is L-valinol, and the drug is exemplified by SN-38.
The structure is shown in formula 4.
##STR00003##
[0069] In this embodiment, an amide bond is first formed between
the carboxylic acid of an amino acid such as lysine and the amino
group of valinol, using orthogonal protecting groups for the lysine
amino groups. The protecting group on the N-terminus of lysine is
removed, keeping the protecting group on the side chain of lysine
intact, and the N-terminus is coupled to the carboxyl group on the
defined PEG with azide (or acetylene) at the other end. The
hydroxyl group of valinol is then attached to the 20-chloroformate
derivative of 10-hydroxy-protected SN-38, and this intermediate is
coupled to an L2 component carrying the antibody-binding moiety as
well as the complementary acetylene (or azide) group involved in
the click cycloaddition chemistry. Finally, removal of protecting
groups at both lysine side chain and SN-38 gives the product of
this example, shown in formula 3.
[0070] While not wishing to be bound by theory, the small MW SN-38
product, namely valinol-SN-38 carbonate, generated after
intracellular proteolysis, has the additional pathway of liberation
of intact SN-38 through intramolecular cyclization involving the
amino group of valinol and the carbonyl of the carbonate.
[0071] In another preferred embodiment, A' of the general formula 2
is A-OH, whereby A-OH is a collapsible moiety such as 4-aminobenzyl
alcohol or a substituted 4-aminobenzyl alcohol substituted with a
C.sub.1-C.sub.10 alkyl group at the benzylic position, and the
latter, via its amino group, is attached to an L-amino acid or a
polypeptide comprising up to four L-amino acid moieties; wherein
the N-terminus is attached to a cross-linker terminating in the
antibody-binding group.
[0072] An example of a preferred embodiment is given below, wherein
the A-OH embodiment of A' of general formula (2) is derived from a
substituted 4-aminobenzyl alcohol, and `AA` is comprised of a
single L-amino acid with m=1 in the general formula (2), and the
drug is exemplified with SN-38. The structure is represented below
(formula 5, referred to as MAb-CLX-SN-38). The single amino acid AA
is selected from any one of the following L-amino acids: alanine,
arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic
acid, glycine, histidine, isoleucine, leucine, lysine, methionine,
phenylalanine, proline, serine, threonine, tryptophan, tyrosine,
and valine. The substituent R on 4-aminobenzyl alcohol moiety (A-OH
embodiment of A') is hydrogen or an alkyl group selected from
C1-C10 alkyl groups.
##STR00004##
[0073] An embodiment of MAb-CLX-SN-38 of formula 5, wherein the
single amino acid AA is L-lysine and R=H, and the drug is
exemplified by SN-38 (formula 6; referred to as
MAb-CL2A-SN-38).
##STR00005##
[0074] Other embodiments are possible within the context of
10-hydroxy-containing camptothecins, such as SN-38. In the example
of SN-38 as the drug, the more reactive 10-hydroxy group of the
drug is derivatized leaving the 20-hydroxyl group unaffected.
Within the general formula 2, A' is a substituted ethylenediamine.
An example of this embodiment is represented by the formula `7`
below, wherein the phenolic hydroxyl group of SN-38 is derivatized
as a carbamate with a substituted ethylenediamine, with the other
amine of the diamine derivatized as a carbamate with a
4-aminobenzyl alcohol, and the latter's amino group is attached to
Phe-Lys dipeptide. In this structure (formula 7), R and R' are
independently hydrogen or methyl. It is referred to as
MAb-CL17-SN-38 or MAb-CL2E-SN-38, when R=R'=methyl.
##STR00006##
[0075] In a preferred embodiment, AA comprises a polypeptide
moiety, preferably a di, tri or tetrapeptide, that is cleavable by
intracellular peptidase. Examples are: Ala-Leu, Leu-Ala-Leu, and
Ala-Leu-Ala-Leu (SEQ ID NO: 13) (Trouet et al., 1982).
[0076] In another preferred embodiment, the L1 component of the
conjugate contains a defined polyethyleneglycol (PEG) spacer with
1-30 repeating monomeric units. In a further preferred embodiment,
PEG is a defined PEG with 1-12 repeating monomeric units. The
introduction of PEG may involve using heterobifunctionalized PEG
derivatives which are available commercially. The
heterobifunctional PEG may contain an azide or acetylene group. An
example of a heterobifunctional defined PEG containing 8 repeating
monomeric units, with `NHS` being succinimidyl, is given below in
formula 8:
##STR00007##
[0077] In a preferred embodiment, L2 has a plurality of acetylene
(or azide) groups, ranging from 2-40, but preferably 2-20, and more
preferably 2-5, and a single targeting vector-binding moiety.
[0078] A representative SN-38 conjugate of an antibody containing
multiple drug molecules and a single targeting vector-binding
moiety is shown below. The `L2` component of this structure is
appended to 2 acetylenic groups, resulting in the attachment of two
azide-appended SN-38 molecules. The bonding to MAb is represented
as a succinimide.
##STR00008##
[0079] In preferred embodiments, when the bifunctional drug
contains a thiol-reactive moiety as the antibody-binding group, the
thiols on the antibody are generated on the lysine groups of the
antibody using a thiolating reagent. Methods for introducing thiol
groups onto antibodies by modifications of MAb's lysine groups are
well known in the art (Wong in Chemistry of protein conjugation and
cross-linking, CRC Press, Inc., Boca Raton, Fla. (1991), pp 20-22).
Alternatively, mild reduction of interchain disulfide bonds on the
antibody (Willner et al., Bioconjugate Chem. 4:521-527 (1993))
using reducing agents such as dithiothreitol (DTT) can generate
7-to-10 thiols on the antibody; which has the advantage of
incorporating multiple drug moieties in the interchain region of
the MAb away from the antigen-binding region.
[0080] In a preferred embodiment, the chemotherapeutic moiety is
selected from the group consisting of doxorubicin (DOX),
epirubicin, morpholinodoxorubicin (morpholino-DOX),
cyanomorpholino-doxorubicin (cyanomorpholino-DOX),
2-pyrrolino-doxorubicin (2-PDOX), CPT, 10-hydroxy camptothecin,
SN-38, topotecan, lurtotecan, 9-aminocamptothecin,
9-nitrocamptothecin, taxanes, geldanamycin, ansamycins, and
epothilones. In a more preferred embodiment, the chemotherapeutic
moiety is SN-38. Preferably, in the conjugates of the preferred
embodiments, the antibody links to at least one chemotherapeutic
moiety; preferably 1 to about 12 chemotherapeutic moieties; most
preferably about 6 to about 12 chemotherapeutic moieties.
[0081] Furthermore, in a preferred embodiment, the linker component
`L2` comprises a thiol group that reacts with a thiol-reactive
residue introduced at one or more lysine side chain amino groups of
said antibody. In such cases, the antibody is pre-derivatized with
a thiol-reactive group such as a maleimide, vinylsulfone,
bromoacetamide, or iodoacetamide by procedures well described in
the art.
[0082] In the context of these embodiments, a process was
surprisingly discovered by which CPT drug-linkers can be prepared
wherein CPT additionally has a 10-hydroxyl group. This process
involves, but is not limited to, the protection of the 10-hydroxyl
group as a t-butyloxycarbonyl (BOC) derivative, followed by the
preparation of the penultimate intermediate of the drug-linker
conjugate. Usually, removal of BOC group requires treatment with
strong acid such as trifluoroacetic acid (TFA). Under these
conditions, the CPT 20-O-linker carbonate, containing protecting
groups to be removed, is also susceptible to cleavage, thereby
giving rise to unmodified CPT. In fact, the rationale for using a
mildly removable methoxytrityl (MMT) protecting group for the
lysine side chain of the linker molecule, as enunciated in the art,
was precisely to avoid this possibility (Walker et al., 2002). It
was discovered that selective removal of phenolic BOC protecting
group is possible by carrying out reactions for short durations,
optimally 3-to-5 minutes. Under these conditions, the predominant
product was that in which the `BOC` at 10-hydroxyl position was
removed, while the carbonate at `20` position was intact.
[0083] An alternative approach involves protecting the CPT analog's
10-hydroxy position with a group other than `BOC`, such that the
final product is ready for conjugation to antibodies without a need
for deprotecting the 10-OH protecting group. The 10-hydroxy
protecting group, which converts the 10-OH into a phenolic
carbonate or a phenolic ester, is readily deprotected by
physiological pH conditions or by esterases after in vivo
administration of the conjugate. The faster removal of a phenolic
carbonate at the 10 position vs. a tertiary carbonate at the 20
position of 10-hydroxycamptothecin under physiological condition
has been described by He et al. (He et al., Bioorganic &
Medicinal Chemistry 12: 4003-4008 (2004)). A 10-hydroxy protecting
group on SN-38 can be `COR` where R can be a substituted alkyl such
as "N(CH.sub.3).sub.2--(CH.sub.2).sub.n--" where n is 1-10 and
wherein the terminal amino group is optionally in the form of a
quaternary salt for enhanced aqueous solubility, or a simple alkyl
residue such as "CH.sub.3--(CH.sub.2).sub.n--" where n is 0-10, or
it can be an alkoxy moiety such as "CH.sub.3--(CH.sub.2)n-O--"
where n is 0-10, or "N(CH.sub.3).sub.2--(CH.sub.2).sub.n--O--"
where n is 2-10, or
"R.sub.1O--(CH.sub.2--CH.sub.2--O).sub.n--CH.sub.2CH.sub.2--O--"
where R.sub.1 is ethyl or methyl and n is an integer with values of
0-10. These 10-hydroxy derivatives are readily prepared by
treatment with the chloroformate of the chosen reagent, if the
final derivative is to be a carbonate. Typically, the
10-hydroxy-containing camptothecin such as SN-38 is treated with a
molar equivalent of the chloroformate in dimethylformamide using
triethylamine as the base. Under these conditions, the 20-OH
position is unaffected. For forming 10-O-esters, the acid chloride
of the chosen reagent is used.
[0084] In a preferred process of the preparation of a conjugate of
a drug derivative and an antibody of the general formula 2, wherein
the descriptors L2, L1, AA and A-X are as described in earlier
sections, the bifunctional drug moiety,
[L2]-[L1]-[AA].sub.m-[A-X]-Drug is first prepared, followed by the
conjugation of the bifunctional drug moiety to the antibody.
[0085] In a preferred process of the preparation of a conjugate of
a drug derivative and an antibody of the general formula 2, wherein
the descriptors L2, L1, AA and A-OH are as described in earlier
sections, the bifunctional drug moiety is prepared by first linking
A-OH to the C-terminus of AA via an amide bond, followed by
coupling the amine end of AA to a carboxylic acid group of L1. If
AA is absent (i.e. m=0), A-OH is directly attached to L1 via an
amide bond. The cross-linker, [L1]-[AA].sub.m-[A-OH], is attached
to drug's hydroxyl or amino group, and this is followed by
attachment to the L1 moiety, by taking recourse to the reaction
between azide (or acetylene) and acetylene (or azide) groups in L1
and L2 via click chemistry.
[0086] In a preferred process of the preparation of a conjugate of
a drug derivative and an antibody of the general formula 2, wherein
the descriptors L2, L1, AA and A-OH are as described in earlier
sections, the purified conjugate is contained in the pH range of
5.5 to 7.5 in any of the following Good's biological buffers
derived from: 2-(N-morpholino)ethanesulfonic acid (MES),
N-(2-acetamido)-2-iminodiacetic acid (ADA),
1,4-piperazinediethanesulfonic acid (PIPES),
N-(2-acetamido)-2-aminoethanesulfonic acid (ACES),
N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES),
N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), and
N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) or HEPES.
The most preferred buffer is 25 mM MES, pH 6.5. In a further
preferred process of preparation of the specified conjugates, the
conjugate solution is formulated with excipients such as trehalose
and polysorbate 80 and lyophilized, and the lyophilized
preparations are preferably stored at 2-8 deg.
[0087] In one embodiment, the antibody is a monoclonal antibody
(MAb). In a further embodiment, the antibody may be a multivalent
and/or multispecific MAb. The antibody may be a murine, chimeric,
humanized, or human monoclonal antibody, and said antibody may be
in intact, fragment (Fab, Fab', F(ab).sub.2, F(ab').sub.2), or
sub-fragment (single-chain constructs) form, or of an IgG1, IgG2a,
IgG3, IgG4, IgA isotype, or submolecules therefrom.
[0088] In a preferred embodiment, the intracellularly-cleavable
moiety may be cleaved after it is internalized into the cell upon
binding by the MAb-drug conjugate to a receptor thereof, and
particularly cleaved by esterases and peptidases.
[0089] Preparation of Antibodies
[0090] The complexes described herein may comprise one or more
monoclonal antibodies or fragments thereof. Rodent monoclonal
antibodies to specific antigens may be obtained by methods known to
those skilled in the art. (See, e.g., Kohler and Milstein, Nature
256: 495 (1975), and Coligan et al. (eds.), CURRENT PROTOCOLS IN
IMMUNOLOGY, VOL. 1, pages 2.5.1-2.6.7 (John Wiley & Sons
1991)).
[0091] General techniques for cloning murine immunoglobulin
variable domains have been disclosed, for example, by the
publication of Orlandi et al., Proc. Nat'l Acad. Sci. USA 86: 3833
(1989). Techniques for constructing chimeric antibodies are well
known to those of skill in the art. As an example, Leung et al.,
Hybridoma 13:469 (1994), disclose how they produced an LL2 chimera
by combining DNA sequences encoding the V.sub.k and V.sub.H domains
of LL2 monoclonal antibody, an anti-CD22 antibody, with respective
human and IgG.sub.1 constant region domains. This publication also
provides the nucleotide sequences of the LL2 light and heavy chain
variable regions, V.sub.k and V.sub.H, respectively. Techniques for
producing humanized antibodies are disclosed, for example, by Jones
et al., Nature 321: 522 (1986), Riechmann et al., Nature 332: 323
(1988), Verhoeyen et al., Science 239: 1534 (1988), Carter et al.,
Proc. Nat'l Acad. Sci. USA 89: 4285 (1992), Sandhu, Crit. Rev.
Biotech. 12: 437 (1992), and Singer et al., J. Immun. 150: 2844
(1993).
[0092] A chimeric antibody is a recombinant protein that contains
the variable domains including the CDRs derived from one species of
animal, such as a rodent antibody, while the remainder of the
antibody molecule; i.e., the constant domains, is derived from a
human antibody. Accordingly, a chimeric monoclonal antibody can
also be humanized by replacing the sequences of the murine FR in
the variable domains of the chimeric antibody with one or more
different human FR. Specifically, mouse CDRs are transferred from
heavy and light variable chains of the mouse immunoglobulin into
the corresponding variable domains of a human antibody. As simply
transferring mouse CDRs into human FRs often results in a reduction
or even loss of antibody affinity, additional modification might be
required in order to restore the original affinity of the murine
antibody. This can be accomplished by the replacement of one or
more some human residues in the FR regions with their murine
counterparts to obtain an antibody that possesses good binding
affinity to its epitope. (See, e.g., Tempest et al., Biotechnology
9:266 (1991) and Verhoeyen et al., Science 239: 1534 (1988)).
[0093] A fully human antibody can be obtained from a transgenic
non-human animal. (See, e.g., Mendez et al., Nature Genetics, 15:
146-156, 1997; U.S. Pat. No. 5,633,425.) Methods for producing
fully human antibodies using either combinatorial approaches or
transgenic animals transformed with human immunoglobulin loci are
known in the art (e.g., Mancini et al., 2004, New Microbiol.
27:315-28; Conrad and Scheller, 2005, Comb. Chem. High Throughput
Screen. 8:117-26; Brekke and Loset, 2003, Curr. Opin. Pharmacol.
3:544-50). Such fully human antibodies are expected to exhibit even
fewer side effects than chimeric or humanized antibodies and to
function in vivo as essentially endogenous human antibodies. In
certain embodiments, the claimed methods and procedures may utilize
human antibodies produced by such techniques.
[0094] In one alternative, the phage display technique may be used
to generate human antibodies (e.g., Dantas-Barbosa et al., 2005.
Genet. Mol. Res. 4:126-40). Human antibodies may be generated from
normal humans or from humans that exhibit a particular disease
state, such as a hematopoietic cancer (Dantas-Barbosa et al.,
2005). The advantage to constructing human antibodies from a
diseased individual is that the circulating antibody repertoire may
be biased towards antibodies against disease-associated
antigens.
[0095] In one non-limiting example of this methodology,
Dantas-Barbosa et al. (2005) constructed a phage display library of
human Fab antibody fragments from osteosarcoma patients. Generally,
total RNA was obtained from circulating blood lymphocytes (Id.)
Recombinant Fab were cloned from the .mu., .gamma. and .kappa.
chain antibody repertoires and inserted into a phage display
library (Id.) RNAs were converted to cDNAs and used to make Fab
cDNA libraries using specific primers against the heavy and light
chain immunoglobulin sequences (Marks et al., 1991, J. Mol. Biol.
222:581-97). Library construction was performed according to
Andris-Widhopf et al. (2000, In: Phage Display Laboratory Manual,
Barbas et al. (eds), 1.sup.st edition, Cold Spring Harbor
Laboratory Press, Cold Spring Harbor, N.Y. pp. 9.1 to 9.22). The
final Fab fragments were digested with restriction endonucleases
and inserted into the bacteriophage genome to make the phage
display library. Such libraries may be screened by standard phage
display methods. The skilled artisan will realize that this
technique is exemplary only and any known method for making and
screening human antibodies or antibody fragments by phage display
may be utilized.
[0096] In another alternative, transgenic animals that have been
genetically engineered to produce human antibodies may be used to
generate antibodies against essentially any immunogenic target,
using standard immunization protocols as discussed above. Methods
for obtaining human antibodies from transgenic mice are described
by Green et al., Nature Genet. 7:13 (1994), Lonberg et al., Nature
368:856 (1994), and Taylor et al., Int. Immun. 6:579 (1994). A
non-limiting example of such a system is the XENOMOUSE.RTM.) (e.g.,
Green et al., 1999, J. Immunol. Methods 231:11-23) from Abgenix
(Fremont, Calif.). In the XENOMOUSE.RTM. and similar animals, the
mouse antibody genes have been inactivated and replaced by
functional human antibody genes, while the remainder of the mouse
immune system remains intact.
[0097] The XENOMOUSE.RTM. was transformed with germline-configured
YACs (yeast artificial chromosomes) that contained portions of the
human IgH and Ig kappa loci, including the majority of the variable
region sequences, along accessory genes and regulatory sequences.
The human variable region repertoire may be used to generate
antibody producing B cells, which may be processed into hybridomas
by known techniques. A XENOMOUSE.RTM. immunized with a target
antigen will produce human antibodies by the normal immune
response, which may be harvested and/or produced by standard
techniques discussed above. A variety of strains of XENOMOUSE.RTM.
are available, each of which is capable of producing a different
class of antibody. Transgenically produced human antibodies have
been shown to have therapeutic potential, while retaining the
pharmacokinetic properties of normal human antibodies (Green et
al., 1999). The skilled artisan will realize that the claimed
compositions and methods are not limited to use of the
XENOMOUSE.RTM. system but may utilize any transgenic animal that
has been genetically engineered to produce human antibodies.
[0098] Antibody Cloning and Production
[0099] Various techniques, such as production of chimeric or
humanized antibodies, may involve procedures of antibody cloning
and construction. The antigen-binding V.sub..kappa. (variable light
chain) and V.sub.H (variable heavy chain) sequences for an antibody
of interest may be obtained by a variety of molecular cloning
procedures, such as RT-PCR, 5'-RACE, and cDNA library screening.
The V genes of an antibody from a cell that expresses a murine
antibody can be cloned by PCR amplification and sequenced. To
confirm their authenticity, the cloned V.sub.L and V.sub.H genes
can be expressed in cell culture as a chimeric Ab as described by
Orlandi et al., (Proc. Natl. Acad. Sci., USA, 86: 3833 (1989)).
Based on the V gene sequences, a humanized antibody can then be
designed and constructed as described by Leung et al. (Mol.
Inmmunol., 32: 1413 (1995)).
[0100] cDNA can be prepared from any known hybridoma line or
transfected cell line producing a murine antibody by general
molecular cloning techniques (Sambrook et al., Molecular Cloning, A
laboratory manual, 2.sup.nd Ed (1989)). The V.sub..kappa. sequence
for the antibody may be amplified using the primers VK1BACK and
VK1FOR (Orlandi et al., 1989) or the extended primer set described
by Leung et al. (BioTechniques, 15: 286 (1993)). The V.sub.H
sequences can be amplified using the primer pair VH1BACK/VH1FOR
(Orlandi et al., 1989) or the primers annealing to the constant
region of murine IgG described by Leung et al. (Hybridoma, 13:469
(1994)). Humanized V genes can be constructed by a combination of
long oligonucleotide template syntheses and PCR amplification as
described by Leung et al. (Mol. Inmmunol., 32: 1413 (1995)).
[0101] PCR products for V.sub..kappa. can be subcloned into a
staging vector, such as a pBR327-based staging vector, VKpBR, that
contains an Ig promoter, a signal peptide sequence and convenient
restriction sites. PCR products for V.sub.H can be subcloned into a
similar staging vector, such as the pBluescript-based VHpBS.
Expression cassettes containing the V.sub..kappa. and V.sub.H
sequences together with the promoter and signal peptide sequences
can be excised from VKpBR and VHpBS and ligated into appropriate
expression vectors, such as pKh and pG1g, respectively (Leung et
al., Hybridoma, 13:469 (1994)). The expression vectors can be
co-transected into an appropriate cell and supernatant fluids
monitored for production of a chimeric, humanized or human
antibody. Alternatively, the V.sub..kappa. and V.sub.H expression
cassettes can be excised and subcloned into a single expression
vector, such as pdHL2, as described by Gillies et al. (J. Immunol.
Methods 125:191 (1989) and also shown in Losman et al., Cancer,
80:2660 (1997)).
[0102] In an alternative embodiment, expression vectors may be
transfected into host cells that have been pre-adapted for
transfection, growth and expression in serum-free medium. Exemplary
cell lines that may be used include the Sp/EEE, Sp/ESF and Sp/ESF-X
cell lines (see, e.g., U.S. Pat. Nos. 7,531,327; 7,537,930 and
7,608,425; the Examples section of each of which is incorporated
herein by reference). These exemplary cell lines are based on the
Sp2/0 myeloma cell line, transfected with a mutant Bcl-EEE gene,
exposed to methotrexate to amplify transfected gene sequences and
pre-adapted to serum-free cell line for protein expression.
[0103] Antibody Allotypes
[0104] Immunogenicity of therapeutic antibodies is associated with
increased risk of infusion reactions and decreased duration of
therapeutic response (Baert et al., 2003, N Engl J Med 348:602-08).
The extent to which therapeutic antibodies induce an immune
response in the host may be determined in part by the allotype of
the antibody (Stickler et al., 2011, Genes and Immunity 12:213-21).
Antibody allotype is related to amino acid sequence variations at
specific locations in the constant region sequences of the
antibody. The allotypes of IgG antibodies containing a heavy chain
.gamma.-type constant region are designated as Gm allotypes (1976,
J Immunol 117:1056-59).
[0105] For the common IgG1 human antibodies, the most prevalent
allotype is G1m1 (Stickler et al., 2011, Genes and Immunity
12:213-21). However, the G1m3 allotype also occurs frequently in
Caucasians (Id.). It has been reported that G1m1 antibodies contain
allotypic sequences that tend to induce an immune response when
administered to non-G1m1 (nG1m1) recipients, such as G1m3 patients
(Id.). Non-G1m1 allotype antibodies are not as immunogenic when
administered to G1m1 patients (Id.).
[0106] The human G1m1 allotype comprises the amino acids D12 (Kabat
position 356) and L14 (Kabat position 358) in the CH3 sequence of
the heavy chain IgG1. The nG1m1 allotype comprises the amino acids
E12 and M14 at the same locations. Both G1m1 and nG1m1 allotypes
comprise an E13 residue in between the two variable sites and the
allotypes are sometimes referred to as DEL and EEM allotypes. A
non-limiting example of the heavy chain constant region sequence
for an nG1m1 (G1m3) allotype antibody is shown in Example 1 below
for the exemplary antibody veltuzumab (SEQ ID NO:14).
[0107] With regard to therapeutic antibodies, veltuzumab (G1m3) and
rituximab (G1m17,1) are, respectively, humanized and chimeric IgG1
antibodies against CD20, of use for therapy of a wide variety of
hematological malignancies and/or autoimmune diseases. Table 1
compares the allotype sequences of the heavy chain constant region
sequences of rituximab vs. veltuzumab. The light chain constant
region sequences of the two antibodies are identical. As shown in
Table 1, rituximab (G1m17,1) is a DEL allotype IgG1, with an
additional sequence variation at Kabat position 214 (heavy chain
CH1) of lysine in rituximab vs. arginine in veltuzumab. It has been
reported that veltuzumab is less immunogenic in subjects than
rituximab (see, e.g., Morchhauser et al., 2009, J Clin Oncol
27:3346-53; Goldenberg et al., 2009, Blood 113:1062-70; Robak &
Robak, 2011, BioDrugs 25:13-25), an effect that has been attributed
to the difference between humanized and chimeric antibodies.
However, the difference in allotypes between the EEM and DEL
allotypes likely also accounts for the lower immunogenicity of
veltuzumab.
TABLE-US-00001 TABLE 1 Allotypes of Rituximab vs. Veltuzumab Heavy
chain position and associated allotypes 214 356/358 431 Complete
allotype (allotype) (allotype) (allotype) Rituximab G1m17,1 K 17
D/L 1 A -- Veltuzumab G1m3 R 3 E/M -- A --
[0108] In order to reduce the immunogenicity of therapeutic
antibodies in individuals of nG1m1 genotype, it is desirable to
select the allotype of the antibody to correspond to the EEM
allotype, with a glutamate residue at Kabat position 356, a
methionine at Kabat position 358, and preferably an arginine
residue at Kabat position 214. Surprisingly, it was found that
repeated subcutaneous administration of G1m3 antibodies over a long
period of time did not result in a significant immune response.
[0109] Known Antibodies
[0110] In various embodiments, the claimed methods and compositions
may utilize any of a variety of antibodies known in the art.
Antibodies of use may be commercially obtained from a number of
known sources. For example, a variety of antibody secreting
hybridoma lines are available from the American Type Culture
Collection (ATCC, Manassas, Va.). A large number of antibodies
against various disease targets have been deposited at the ATCC
and/or have published variable region sequences and are available
for use in the claimed methods and compositions. See, e.g., U.S.
Pat. Nos. 7,312,318; 7,282,567; 7,151,164; 7,074,403; 7,060,802;
7,056,509; 7,049,060; 7,045,132; 7,041,803; 7,041,802; 7,041,293;
7,038,018; 7,037,498; 7,012,133; 7,001,598; 6,998,468; 6,994,976;
6,994,852; 6,989,241; 6,974,863; 6,965,018; 6,964,854; 6,962,981;
6,962,813; 6,956,107; 6,951,924; 6,949,244; 6,946,129; 6,943,020;
6,939,547; 6,921,645; 6,921,645; 6,921,533; 6,919,433; 6,919,078;
6,916,475; 6,905,681; 6,899,879; 6,893,625; 6,887,468; 6,887,466;
6,884,594; 6,881,405; 6,878,812; 6,875,580; 6,872,568; 6,867,006;
6,864,062; 6,861,511; 6,861,227; 6,861,226; 6,838,282; 6,835,549;
6,835,370; 6,824,780; 6,824,778; 6,812,206; 6,793,924; 6,783,758;
6,770,450; 6,767,711; 6,764,688; 6,764,681; 6,764,679; 6,743,898;
6,733,981; 6,730,307; 6,720,155; 6,716,966; 6,709,653; 6,693,176;
6,692,908; 6,689,607; 6,689,362; 6,689,355; 6,682,737; 6,682,736;
6,682,734; 6,673,344; 6,653,104; 6,652,852; 6,635,482; 6,630,144;
6,610,833; 6,610,294; 6,605,441; 6,605,279; 6,596,852; 6,592,868;
6,576,745; 6,572,856; 6,566,076; 6,562,618; 6,545,130; 6,544,749;
6,534,058; 6,528,625; 6,528,269; 6,521,227; 6,518,404; 6,511,665;
6,491,915; 6,488,930; 6,482,598; 6,482,408; 6,479,247; 6,468,531;
6,468,529; 6,465,173; 6,461,823; 6,458,356; 6,455,044; 6,455,040,
6,451,310; 6,444,206, 6,441,143; 6,432,404; 6,432,402; 6,419,928;
6,413,726; 6,406,694; 6,403,770; 6,403,091; 6,395,276; 6,395,274;
6,387,350; 6,383,759; 6,383,484; 6,376,654; 6,372,215; 6,359,126;
6,355,481; 6,355,444; 6,355,245; 6,355,244; 6,346,246; 6,344,198;
6,340,571; 6,340,459; 6,331,175; 6,306,393; 6,254,868; 6,187,287;
6,183,744; 6,129,914; 6,120,767; 6,096,289; 6,077,499; 5,922,302;
5,874,540; 5,814,440; 5,798,229; 5,789,554; 5,776,456; 5,736,119;
5,716,595; 5,677,136; 5,587,459; 5,443,953, 5,525,338, the Examples
section of each of which is incorporated herein by reference. These
are exemplary only and a wide variety of other antibodies and their
hybridomas are known in the art. The skilled artisan will realize
that antibody sequences or antibody-secreting hybridomas against
almost any disease-associated antigen may be obtained by a simple
search of the ATCC, NCBI and/or USPTO databases for antibodies
against a selected disease-associated target of interest. The
antigen binding domains of the cloned antibodies may be amplified,
excised, ligated into an expression vector, transfected into an
adapted host cell and used for protein production, using standard
techniques well known in the art.
[0111] Exemplary known antibodies that may be of use for therapy of
cancer or autoimmune disease within the scope of the claimed
methods and compositions include, but are not limited to, LL1
(anti-CD74), LL2 and RFB4 (anti-CD22), RS7 (anti-epithelial
glycoprotein-1 (EGP-1)), PAM4 and KC4 (both anti-mucin), MN-14
(anti-carcinoembryonic antigen (CEA or CEACAM5, also known as
CD66e)), Mu-9 (anti-colon-specific antigen-p), Immu-31 (an
anti-alpha-fetoprotein), TAG-72 (e.g., CC49), Tn, J591 or HuJ591
(anti-PSMA (prostate-specific membrane antigen)), AB-PG1-XG1-026
(anti-PSMA dimer), D2/B (anti-PSMA), G250 (an anti-carbonic
anhydrase IX MAb), hL243 (anti-HLA-DR), R1 (anti-IGF-1R), A20
(anti-CD20), A19 (anti-CD19), MN-3 or MN-15 (anti-CEACAM6),
alemtuzumab (anti-CD52), bevacizumab (anti-VEGF), cetuximab
(anti-EGFR), gemtuzumab (anti-CD33), ibritumomab tiuxetan
(anti-CD20); panitumumab (anti-EGFR); rituximab (anti-CD20);
tositumomab (anti-CD20); GA101 (anti-CD20); and trastuzumab
(anti-ErbB2). Such antibodies are known in the art (e.g., U.S. Pat.
Nos. 5,686,072; 5,874,540; 6,107,090; 6,183,744; 6,306,393;
6,653,104; 6,730,300; 6,899,864; 6,926,893; 6,962,702; 7,074,403;
7,230,084; 7,238,785; 7,238,786; 7,256,004; 7,282,567; 7,300,655;
7,312,318; 7,585,491; 7,612,180; 7,642,239; and U.S. Patent
Application Publ. No. 20040202666 (now abandoned); 20050271671; and
20060193865; the Examples section of each incorporated herein by
reference.)
[0112] Specific known antibodies of use include, but are not
limited to, hPAM4 (U.S. Pat. No. 7,282,567), hA20 (U.S. Pat. No.
7,251,164), hA19 (U.S. Pat. No. 7,109,304), hIMMU31 (U.S. Pat. No.
7,300,655), hLL1 (U.S. Pat. No. 7,312,318,), hLL2 (U.S. Pat. No.
7,074,403), hMu-9 (U.S. Pat. No. 7,387,773), hL243 (U.S. Pat. No.
7,612,180), hMN-14 (U.S. Pat. No. 6,676,924), hMN-15 (U.S. Pat. No.
7,541,440), hR1 (U.S. patent application Ser. No. 12/689,336), hRS7
(U.S. Pat. No. 7,238,785), hMN-3 (U.S. Pat. No. 7,541,440), 15B8
(anti-CD40, U.S. Pat. No. 7,820,170), AB-PG1-XG1-026 (U.S. patent
application Ser. No. 11/983,372, deposited as ATCC PTA-4405 and
PTA-4406) and D2/B (WO 2009/130575). Other known antibodies are
disclosed, for example, in U.S. Pat. Nos. 5,686,072; 5,874,540;
6,107,090; 6,183,744; 6,306,393; 6,653,104; 6,730.300; 6,899,864;
6,926,893; 6,962,702; 7,074,403; 7,230,084; 7,238,785; 7,238,786;
7,256,004; 7,282,567; 7,300,655; 7,312,318; 7,585,491; 7,612,180;
7,642,239; and U.S. Patent Application Publ. No. 20040202666 (now
abandoned); 20050271671; and 20060193865. The text of each recited
patent or application is incorporated herein by reference with
respect to the Figures and Examples sections.
[0113] Anti-TNF-.alpha. antibodies are known in the art and may be
of use to treat immune diseases, such as autoimmune disease, immune
dysfunction (e.g., graft-versus-host disease, organ transplant
rejection) or diabetes. Known antibodies against TNF-.alpha.
include the human antibody CDP571 (Ofei et al., 2011, Diabetes
45:881-85); murine antibodies MTNFAI, M2TNFAI, M3TNFAI, M3TNFABI,
M302B and M303 (Thermo Scientific, Rockford, Ill.); infliximab
(Centocor, Malvern, Pa.); certolizumab pegol (UCB, Brussels,
Belgium); and adalimumab (Abbott, Abbott Park, Il.). These and many
other known anti-TNF-.alpha. antibodies may be used in the claimed
methods and compositions. Other antibodies of use for therapy of
immune dysregulatory or autoimmune disease include, but are not
limited to, anti-B-cell antibodies such as veltuzumab, epratuzumab,
milatuzumab or hL243; tocilizumab (anti-IL-6 receptor); basiliximab
(anti-CD25); daclizumab (anti-CD25); efalizumab (anti-CD11a); GA101
(anti-CD20; Glycart Roche); muromonab-CD3 (anti-CD3 receptor);
Benlysta (Human Genome Sciences); anti-CD40L (UCB, Brussels,
Belgium); natalizumab (anti-.alpha.4 integrin) and omalizumab
(anti-IgE).
[0114] Type-1 and Type-2 diabetes may be treated using known
antibodies against B-cell antigens, such as CD22 (epratuzumab),
CD74 (milatuzumab), CD19 (hA19), CD20 (veltuzumab) or HLA-DR
(hL243) (see, e.g., Winer et al., 2011, Nature Med 17:610-18).
Anti-CD3 antibodies also have been proposed for therapy of type 1
diabetes (Cernea et al., 2010, Diabetes Metab Rev 26:602-05).
[0115] Macrophage migration inhibitory factor (MIF) is an important
regulator of innate and adaptive immunity and apoptosis. It has
been reported that CD74 is the endogenous receptor for MIF (Leng et
al., 2003, J Exp Med 197:14(7-76). The therapeutic effect of
antagonistic anti-CD74 antibodies on MIF-mediated intracellular
pathways may be of use for treatment of a broad range of disease
states, such as cancers of the bladder, prostate, breast, lung,
colon and chronic lymphocytic leukemia (e.g., Meyer-Siegler et al.,
2004, BMC Cancer 12:34; Shachar & Haran, 2011, Leuk Lymphoma
52:1446-54); autoimmune diseases such as rheumatoid arthritis and
systemic lupus erythematosus (Morand & Leech, 2005, Front
Biosci 10:12-22; Shachar & Haran, 2011, Leuk Lymphoma
52:1446-54); kidney diseases such as renal allograft rejection
(Lan, 2008, Nephron Exp Nephrol. 109:e79-83); and numerous
inflammatory diseases (Meyer-Siegler et al., 2009, Mediators
Inflamm epub Mar. 22, 2009; Takahashi et al., 2009, Respir Res
10:33; Milatuzumab (hLL1) is an exemplary anti-CD74 antibody of
therapeutic use for treatment of MIF-mediated diseases.
[0116] Antibody Fragments
[0117] Antibody fragments which recognize specific epitopes can be
generated by known techniques. The antibody fragments are antigen
binding portions of an antibody, such as F(ab).sub.2, Fab', Fab,
Fv, scFv and the like. Other antibody fragments include, but are
not limited to, F(ab').sub.2 fragments which can be produced by
pepsin digestion of the antibody molecule and Fab' fragments which
can be generated by reducing disulfide bridges of the F(ab').sub.2
fragments. Alternatively, Fab' expression libraries can be
constructed (Huse et al., 1989, Science, 246:1274-1281) to allow
rapid and easy identification of monoclonal Fab' fragments with the
desired specificity.
[0118] A single chain Fv molecule (scFv) comprises a VL domain and
a VH domain. The VL and VH domains associate to form a target
binding site. These two domains are further covalently linked by a
peptide linker (L). Methods for making scFv molecules and designing
suitable peptide linkers are disclosed in U.S. Pat. No. 4,704,692,
U.S. Pat. No. 4,946,778, R. Raag and M. Whitlow, "Single Chain
Fvs." FASEB Vol 9:73-80 (1995) and R. E. Bird and B. W. Walker,
"Single Chain Antibody Variable Regions," TIBTECH, Vol 9: 132-137
(1991).
[0119] An antibody fragment can be prepared by known methods, for
example, as disclosed by Goldenberg, U.S. Pat. Nos. 4,036,945 and
4,331,647 and references contained therein. Also, see Nisonoff et
al., Arch Biochem. Biophys. 89: 230 (1960); Porter, Biochem. J. 73:
119 (1959), Edelman et al., in METHODS IN ENZYMOLOGY VOL. 1, page
422 (Academic Press 1967), and Coligan at pages 2.8.1-2.8.10 and
2.10.-2.10.4.
[0120] A single complementarity-determining region (CDR) is a
segment of the variable region of an antibody that is complementary
in structure to the epitope to which the antibody binds and is more
variable than the rest of the variable region. Accordingly, a CDR
is sometimes referred to as hypervariable region. A variable region
comprises three CDRs. CDR peptides can be obtained by constructing
genes encoding the CDR of an antibody of interest. Such genes are
prepared, for example, by using the polymerase chain reaction to
synthesize the variable region from RNA of antibody-producing
cells. (See, e.g., Larrick et al., Methods: A Companion to Methods
in Enzymology 2: 106 (1991); Courtenay-Luck, "Genetic Manipulation
of Monoclonal Antibodies," in MONOCLONAL ANTIBODIES: PRODUCTION,
ENGINEERING AND CLINICAL APPLICATION, Ritter et al. (eds.), pages
166-179 (Cambridge University Press 1995); and Ward et al.,
"Genetic Manipulation and Expression of Antibodies," in MONOCLONAL
ANTIBODIES: PRINCIPLES AND APPLICATIONS, Birch et al., (eds.),
pages 137-185 (Wiley-Liss, Inc. 1995).
[0121] Another form of an antibody fragment is a single-domain
antibody (dAb), sometimes referred to as a single chain antibody.
Techniques for producing single-domain antibodies are well known in
the art (see, e.g., Cossins et al., Protein Expression and
Purification, 2007, 51:253-59; Shuntao et al., Molec Immunol 2006,
43:1912-19: Tanha et al., J. Biol. Chem. 2001, 276:24774-780).
Single domain antibodies may be obtained, for example, from camels,
alpacas or llamas by standard immunization techniques. (See, e.g.,
Muyldermans et al., TIBS 26:230-235, 2001; Yau et al., J Immunol
Methods 281:161-75, 2003; Maass et al., J Immunol Methods
324:13-25, 2007). They can have potent antigen-binding capacity and
can interact with novel epitopes that are inaccessible to
conventional V.sub.H-V.sub.L pairs. (Muyldermans et al., 2001).
Alpaca serum IgG contains about 50% camelid heavy chain only IgG
antibodies (HCAbs) (Maass et al., 2007). Alpacas may be immunized
with known antigens, such as TNF-.alpha., and single domain
antibodies can be isolated that bind to and neutralize the target
antigen (Maass et al., 2007). PCR primers that amplify virtually
all alpaca antibody coding sequences have been identified and may
be used to construct single domain phage display libraries, which
can be used for antibody fragment isolation by standard biopanning
techniques well known in the art (Maass et al., 2007).
[0122] In certain embodiments, the sequences of antibodies or
antibody fragments, such as the Fc portions of antibodies, may be
varied to optim/ze their physiological characteristics, such as the
half-life in serum. Methods of substituting amino acid sequences in
proteins are widely known in the art, such as by site-directed
mutagenesis (e.g. Sambrook et al., Molecular Cloning, A laboratory
manual, 2.sup.nd Ed, 1989). In preferred embodiments, the variation
may involve the addition or removal of one or more glycosylation
sites in the Fc sequence (e.g., U.S. Pat. No. 6,254,868, the
Examples section of which is incorporated herein by reference). In
other preferred embodiments, specific amino acid substitutions in
the Fc sequence may be made (e.g., Hornick et al., 2000, J Nucl Med
41:355-62; Hinton et al., 2006, J Immunol 176:346-56; Petkova et
al. 2006, Int Immunol 18:1759-69; U.S. Pat. No. 7,217,797).
[0123] Multispecific and Multivalent Antibodies
[0124] Various embodiments may concern use of multispecific and/or
multivalent antibodies. For example, an anti-CD22 antibody or
fragment thereof and an anti-CD20 antibody or fragment thereof may
be joined together by means such as the dock-and-lock technique
described above. Other combinations of antibodies or fragments
thereof may be utilized. For example, the anti-CD22 antibody could
be combined with another antibody against a different epitope of
the same antigen, or alternatively with an antibody against another
antigen, such as CD4, CD5, CD8, CD14, CD15, CD19, CD20, CD21, CD22,
CD23, CD25, CD33, CD37, CD38, CD40, CD40L, CD46, CD52, CD54, CD74,
CD80, CD126, CD138, B7, HM1.24, HLA-DR, an angiogenesis factor,
tenascin, VEGF, PIGF, ED-B fibronectin, an oncogene, an oncogene
product, NCA 66a-d, necrosis antigens, Ii (HLA-DR invariant chain),
IL-2, T101, TAC, IL-6, MUC-1, TRAIL-R1 (DR4) or TRAIL-R2 (DR5).
[0125] Methods for producing bispecific antibodies include
engineered recombinant antibodies which have additional cysteine
residues so that they crosslink more strongly than the more common
immunoglobulin isotypes. (See, e.g., FitzGerald et al, Protein Eng
10:1221-1225, 1997). Another approach is to engineer recombinant
fusion proteins linking two or more different single-chain antibody
or antibody fragment segments with the needed dual specificities.
(See, e.g., Coloma et al., Nature Biotech. 15:159-163, 1997). A
variety of bispecific antibodies can be produced using molecular
engineering. In one form, the bispecific antibody may consist of,
for example, a scFv with a single binding site for one antigen and
a Fab fragment with a single binding site for a second antigen. In
another form, the bispecific antibody may consist of, for example,
an IgG with two binding sites for one antigen and two scFv with two
binding sites for a second antigen.
[0126] Dock-and-Lock (DNL)
[0127] In preferred embodiments, multivalent monospecific or
bispecific antibodies may be produced using the dock-and-lock (DNL)
technology (see, e.g., U.S. Pat. Nos. 7,521,056; 7,550,143;
7,534,866; 7,527,787 and 7,666,400; the Examples section of each of
which is incorporated herein by reference). The DNL method exploits
specific protein/protein interactions that occur between the
regulatory (R) subunits of cAMP-dependent protein kinase (PKA) and
the anchoring domain (AD) of A-kinase anchoring proteins (AKAPs)
(Baillie et al., FEBS Letters. 2005; 579: 3264. Wong and Scott,
Nat. Rev. Mol. Cell Biol. 2004: 5: 959). PKA, which plays a central
role in one of the best studied signal transduction pathways
triggered by the binding of the second messenger cAMP to the R
subunits, was first isolated from rabbit skeletal muscle in 1968
(Walsh et al., J. Biol. Chem. 1968; 243:3763). The structure of the
holoenzyme consists of two catalytic subunits held in an inactive
form by the R subunits (Taylor, J. Biol. Chem. 1989; 264:8443).
Isozymes of PKA are found with two types of R subunits (RI and
RII), and each type has .alpha. and .beta. isoforms (Scott,
Pharmacol. Ther. 1991; 50:123). Thus, there are four types of PKA
regulatory subunits--RI.alpha., RI.beta., RII.alpha. and RII.beta..
The R subunits have been isolated only as stable dimers and the
dimerization domain has been shown to consist of the first 44
amino-terminal residues (Newlon et al., Nat. Struct. Biol. 1999:
6:222). Binding of cAMP to the R subunits leads to the release of
active catalytic subunits for a broad spectrum of serine/threonine
kinase activities, which are oriented toward selected substrates
through the compartmentalization of PKA via its docking with AKAPs
(Scott et al., J. Biol. Chem. 1990; 265; 21561).
[0128] Since the first AKAP, microtubule-associated protein-2, was
characterized in 1984 (Lohmann et al., Proc. Natl. Acad. Sci USA.
1984; 81:6723), more than 50 AKAPs that localize to various
sub-cellular sites, including plasma membrane, actin cytoskeleton,
nucleus, mitochondria, and endoplasmic reticulum, have been
identified with diverse structures in species ranging from yeast to
humans (Wong and Scott, Nat. Rev. Mol. Cell Biol. 2004:5:959). The
AD of AKAPs for PKA is an amphipathic helix of 14-18 residues (Carr
et al., J. Biol. Chem. 1991; 266:14188). The amino acid sequences
of the AD are quite varied among individual AKAPs, with the binding
affinities reported for RII dimers ranging from 2 to 90 nM (Alto et
al., Proc. Natl. Acad. Sci. USA. 2003; 100:4445). AKAPs will only
bind to dimeric R subunits. For human RII.alpha., the AD binds to a
hydrophobic surface formed by the 23 amino-terminal residues
(Colledge and Scott, Trends Cell Biol. 1999; 6:216). Thus, the
dimerization domain and AKAP binding domain of human RII.alpha. are
both located within the same N-terminal 44 amino acid sequence
(Newlon et al., Nat. Struct. Biol. 1999; 6:222; Newlon et al., EMBO
J. 2001; 20:1651), which is termed the DDD herein.
[0129] We have developed a platform technology to utilize the DDD
of human PKA regulatory subunit and the AD of AKAP as an excellent
pair of linker modules for docking any two entities, referred to
hereafter as A and B, into a noncovalent complex, which could be
further locked into a stably tethered structure through the
introduction of cysteine residues into both the DDD and AD at
strategic positions to facilitate the formation of disulfide bonds.
The general methodology of the "dock-and-lock" approach is as
follows. Entity A is constructed by linking a DDD sequence to a
precursor of A, resulting in a first component hereafter referred
to as a. Because the DDD sequence would effect the spontaneous
formation of a dimer, A would thus be composed of a.sub.2. Entity B
is constructed by linking an AD sequence to a precursor of B,
resulting in a second component hereafter referred to as b. The
dimeric motif of DDD contained in a.sub.2 will create a docking
site for binding to the AD sequence contained in b, thus
facilitating a ready association of a.sub.2 and b to form a binary,
trimeric complex composed of a.sub.2b. This binding event is made
irreversible with a subsequent reaction to covalently secure the
two entities via disulfide bridges, which occurs very efficiently
based on the principle of effective local concentration because the
initial binding interactions should bring the reactive thiol groups
placed onto both the DDD and AD into proximity (Chmura et al.,
Proc. Natl. Acad. Sci. USA. 2001; 98:8480) to ligate
site-specifically. Using various combinations of linkers, adaptor
modules and precursors, a wide variety of DNL constructs of
different stoichiometry may be produced and used, including but not
limited to dimeric, trimeric, tetrameric, pentameric and hexameric
DNL constructs (see, e.g., U.S. Pat. Nos. 7,550,143; 7,521,056;
7,534,866; 7,527,787 and 7,666,400.)
[0130] By attaching the DDD and AD away from the functional groups
of the two precursors, such site-specific ligations are also
expected to preserve the original activities of the two precursors.
This approach is modular in nature and potentially can be applied
to link, site-specifically and covalently, a wide range of
substances, including peptides, proteins, antibodies, antibody
fragments, and other effector moieties with a wide range of
activities. Utilizing the fusion protein method of constructing AD
and DDD conjugated effectors described in the Examples below,
virtually any protein or peptide may be incorporated into a DNL
construct. However, the technique is not limiting and other methods
of conjugation may be utilized.
[0131] A variety of methods are known for making fusion proteins,
including nucleic acid synthesis, hybridization and/or
amplification to produce a synthetic double-stranded nucleic acid
encoding a fusion protein of interest. Such double-stranded nucleic
acids may be inserted into expression vectors for fusion protein
production by standard molecular biology techniques (see, e.g.
Sambrook et al., Molecular Cloning, A laboratory manual 2.sup.nd
Ed, 1989). In such preferred embodiments, the AD and/or DDD moiety
may be attached to either the N-terminal or C-terminal end of an
effector protein or peptide. However, the skilled artisan will
realize that the site of attachment of an AD or DDD moiety to an
effector moiety may vary, depending on the chemical nature of the
effector moiety and the part(s) of the effector moiety involved in
its physiological activity. Site-specific attachment of a variety
of effector moieties may be performed using techniques known in the
art, such as the use of bivalent cross-linking reagents and/or
other chemical conjugation techniques.
[0132] The skilled artisan will realize that the DNL technique may
be utilized to produce complexes comprising multiple copies of the
same anti-CD22 or anti-CD20 antibodies, or to attach one or more
anti-CD22 antibodies to one or more anti-CD20 antibodies or an
antibody against a different target antigen expressed by B-cells.
Alternatively, the DNL technique may be used to attach antibodies
to different effector moieties, such as toxins, cytokines, carrier
proteins for siRNA and other known effectors.
[0133] Structure-Function Relationships in AD and DDD Moieties
[0134] For different types of DNL constructs, different AD or DDD
sequences may be utilized. Exemplary DDD and AD sequences are
provided below.
TABLE-US-00002 DDD1 (SEQ ID NO: 15)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA DDD2 (SEQ ID NO: 16)
CGHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA AD1 (SEQ ID NO: 17)
QIEYLAKQIVDNAIQQA AD2 (SEQ ID NO: 18) CGQIEYLAKQIVDNAIQQAGC
[0135] The skilled artisan will realize that DDD1 and DDD2 are
based on the DDD sequence of the human RII.alpha. isoform of
protein kinase A. However, in alternative embodiments, the DDD and
AD moieties may be based on the DDD sequence of the human RI.alpha.
form of protein kinase A and a corresponding AKAP sequence, as
exemplified in DDD3, DDD3C and AD3 below.
TABLE-US-00003 DDD3 (SEQ ID NO: 19)
SLRECELYVQKHNIQALLKDSIVQLCTARPERPMAFLREYFERLEKEEAK DDD3C (SEQ ID
NO: 20) MSCGGSLRECELYVQKHNIQALLKDSIVQLCTARPERPMAFLREYFERLE KEEAK
AD3 (SEQ ID NO: 21) CGFEELAWKIAKMIWSDVFQQGC
[0136] In other alternative embodiments, other sequence variants of
AD and/or DDD moieties may be utilized in construction of the DNL
complexes. For example, there are only four variants of human PKA
DDD sequences, corresponding to the DDD moieties of PKA RI.alpha.,
RII.alpha., RI.beta. and RII.beta.. The RII.alpha. DDD sequence is
the basis of DDD1 and DDD2 disclosed above. The four human PKA DDD
sequences are shown below. The DDD sequence represents residues
1-44 of RII.alpha., 1-44 of RII.beta., 12-61 of RI.alpha. and 13-66
of RI.beta.. (Note that the sequence of DDD1 is modified slightly
from the human PKA RII.alpha. DDD moiety.)
TABLE-US-00004 PKA RI.alpha. (SEQ ID NO: 22)
SLRECELYVQKHNIQALLKDVSIVQLCTARPERPMAFLREYFEKLEKEE AK PKA RI.beta.
(SEQ ID NO: 23) SLKGCELYVQLHGIQQVLKDCIVHLCISKPERPMKFLREHFEKLEKEENR
QILA PKA RII.alpha. (SEQ ID NO: 24)
SHIQIPPGLTELLQGYTVEVGQQPPDLVDFAVEYFTRLREARRQ PKA RII.beta. (SEQ ID
NO: 25) SIEIPAGLTELLQGFTVEVLRHQPADLLEFALQHFTRLQQENER
[0137] The structure-function relationships of the AD and DDD
domains have been the subject of investigation. (See, e.g.,
Burns-Hamuro et al., 2005, Protein Sci 14:2982-92; Carr et al.,
2001, J Biol Chem 276:17332-38; Alto et al., 2003, Proc Natl Acad
Sci USA 100:4445-50; Hundsrucker et al., 2006, Biochem J
396:297-306; Stokka et al., 2006, Biochem J 400:493-99; Gold et
al., 2006. Mol Cell 24:383-95; Kinderman et al., 2006, Mol Cell
24:397-408.)
[0138] For example, Kinderman et al. (2006, Mol Cell 24:397-408)
examined the crystal structure of the AD-DDD binding interaction
and concluded that the human DDD sequence contained a number of
conserved amino acid residues that were important in either dimer
formation or AKAP binding, underlined in SEQ ID NO:15 below. (See
FIG. 1 of Kinderman et al., 2006, incorporated herein by
reference.) The skilled artisan will realize that in designing
sequence variants of the DDD sequence, one would desirably avoid
changing any of the underlined residues, while conservative amino
acid substitutions might be made for residues that are less
critical for dimerization and AKAP binding.
TABLE-US-00005 (SEQ ID NO: 15)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA
[0139] As discussed in more detail below, conservative amino acid
substitutions have been characterized for each of the twenty common
L-amino acids. Thus, based on the data of Kinderman (2006) and
conservative amino acid substitutions, potential alternative DDD
sequences based on SEQ ID NO:15 are shown in Table 2. In devising
Table 2, only highly conservative amino acid substitutions were
considered. For example, charged residues were only substituted for
residues of the same charge, residues with small side chains were
substituted with residues of similar size, hydroxyl side chains
were only substituted with other hydroxyls, etc. Because of the
unique effect of proline on amino acid secondary structure, no
other residues were substituted for proline. Even with such
conservative substitutions, there are over twenty million possible
alternative sequences for the 44 residue peptide
(2.times.3.times.2.times.2.times.2.times.2.times.2.times.2.times.2.times.-
2.times.2.times.2.times.2.times.2.times.2.times.4.times.2.times.2.times.2.-
times.2.times.2.times.4.times.2.times.4). A limited number of such
potential alternative DDD moiety sequences are shown in SEQ ID
NO:26 to SEQ ID NO:45 below. The skilled artisan will realize that
an almost unlimited number of alternative species within the genus
of DDD moieties can be constructed by standard techniques, for
example using a commercial peptide synthesizer or well known
site-directed mutagenesis techniques. The effect of the amino acid
substitutions on AD moiety binding may also be readily determined
by standard binding assays, for example as disclosed in Alto et al.
(2003, Proc Natl Acad Sci USA 100:4445-50).
TABLE-US-00006 TABLE 2 Conservative Amino Acid Substitutions in
DDD1 (SEQ ID NO: 15). Consensus sequence disclosed as SEQ ID NO:
131. S H I Q I P P G L T E L L Q G Y T V E V L R T K N A S D N A S
D K R Q Q P P D L V E F A V E Y F T R L R E A R A N N E D L D S K K
D L K L I I I V V V
TABLE-US-00007 (SEQ ID NO: 26)
THIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 27)
SKIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 28)
SRIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 29)
SHINIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 30)
SHIQIPPALTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 31)
SHIQIPPGLSELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 32)
SHIQIPPGLTDLLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 33)
SHIQIPPGLTELLNGYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 34)
SHIQIPPGLTELLQAYTVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 35)
SHIQIPPGLTELLQGYSVEVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 36)
SHIQIPPGLTELLQGYTVDVLRQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 37)
SHIQIPPGLTELLQGYTVEVLKQQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 38)
SHIQIPPGLTELLQGYTVEVLRNQPPDLVEFAVEYFTRLREARA (SEQ ID NO: 39)
SHIQIPPGLTELLQGYTVEVLRQNPPDLVEFAVEYFTRLREARA (SEQ ID NO: 40)
SHIQIPPGLTELLQGYTVEVLRQQPPELVEFAVEYFTRLREARA (SEQ ID NO: 41)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVDFAVEYFTRLREARA (SEQ ID NO: 42)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFLVEYFTRLREARA (SEQ ID NO: 43)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFIVEYFTRLREARA (SEQ ID NO: 44)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFVVEYFTRLREARA (SEQ ID NO: 45)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVDYFTRLREARA
[0140] Alto et al. (2003, Proc Natl Acad Sci USA 100:4445-50)
performed a bioinformatic analysis of the AD sequence of various
AKAP proteins to design an RII selective AD sequence called AKAP-IS
(SEQ ID NO:17), with a binding constant for DDD of 0.4 nM. The
AKAP-IS sequence was designed as a peptide antagonist of AKAP
binding to PKA. Residues in the AKAP-IS sequence where
substitutions tended to decrease binding to DDD are underlined in
SEQ ID NO:17 below. The skilled artisan will realize that in
designing sequence variants of the AD sequence, one would desirably
avoid changing any of the underlined residues, while conservative
amino acid substitutions might be made for residues that are less
critical for DDD binding. Table 3 shows potential conservative
amino acid substitutions in the sequence of AKAP-IS (AD1, SEQ ID
NO:17), similar to that shown for DDD1 (SEQ ID NO:15) in Table 2
above.
[0141] Even with such conservative substitutions, there are over
thirty-five thousand possible alternative sequences for the 17
residue AD1 (SEQ ID NO: 17) peptide sequence
(2.times.3.times.2.times.4.times.3.times.2.times.2.times.2.times.2.times.-
2.times.2.times.4). A limited number of such potential alternative
AD moiety sequences are shown in SEQ ID NO:46 to SEQ ID NO:63
below. Again, a very large number of species within the genus of
possible AD moiety sequences could be made, tested and used by the
skilled artisan, based on the data of Alto et al. (2003). It is
noted that FIG. 2 of Alto (2003) shows an even large number of
potential amino acid substitutions that may be made, while
retaining binding activity to DDD moieties, based on actual binding
experiments.
TABLE-US-00008 AKAP-IS (SEQ ID NO: 17) QIEYLAKQIVDNAIQQA
TABLE-US-00009 TABLE 3 Conservative Amino Acid Substitutions in AD1
(SEQ ID NO: 17). Consensus sequence disclosed as SEQ ID NO: 132. Q
I E Y L A K Q I V D N A I Q Q A N L D F I R N E Q N N L V T V I S
V
TABLE-US-00010 (SEQ ID NO: 46) NIEYLAKQIVDNAIQQA (SEQ ID NO: 47)
QLEYLAKQIVDNAIQQA (SEQ ID NO: 48) QVEYLAKQIVDNAIQQA (SEQ ID NO: 49)
QIDYLAKQIVDNAIQQA (SEQ ID NO: 50) QIEFLAKQIVDNAIQQA (SEQ ID NO: 51)
QIETLAKQIVDNAIQQA (SEQ ID NO: 52) QIESLAKQIVDNAIQQA (SEQ ID NO: 53)
QIEYIAKQIVDNAIQQA (SEQ ID NO: 54) QIEYVAKQIVDNAIQQA (SEQ ID NO: 55)
QIEYLARQIVDNAIQQA (SEQ ID NO: 56) QIEYLAKNIVDNAIQQA (SEQ ID NO: 57)
QIEYLAKQIVENAIQQA (SEQ ID NO: 58) QIEYLAKQIVDQAIQQA (SEQ ID NO: 59)
QIEYLAKQIVDNAINQA (SEQ ID NO: 60) QIEYLAKQIVDNAIQNA (SEQ ID NO: 61)
QIEYLAKQIVDNAIQQL (SEQ ID NO: 62) QIEYLAKQIVDNAIQQI (SEQ ID NO: 63)
QIEYLAKQIVDNAIQQV
[0142] Gold et al. (2006, Mol Cell 24:383-95) utilized
crystallography and peptide screening to develop a SuperAKAP-IS
sequence (SEQ ID NO:64), exhibiting a five order of magnitude
higher selectivity for the RII isoform of PKA compared with the RI
isoform. Underlined residues indicate the positions of amino acid
substitutions, relative to the AKAP-IS sequence, which increased
binding to the DDD moiety of RII.alpha.. In this sequence, the
N-terminal Q residue is numbered as residue number 4 and the
C-terminal A residue is residue number 20. Residues where
substitutions could be made to affect the affinity for RII.alpha.
were residues 8, 11, 15, 16, 18, 19 and 20 (Gold et al., 2006). It
is contemplated that in certain alternative embodiments, the
SuperAKAP-IS sequence may be substituted for the AKAP-IS AD moiety
sequence to prepare DNL constructs. Other alternative sequences
that might be substituted for the AKAP-IS AD sequence are shown in
SEQ ID NO:65-67. Substitutions relative to the AKAP-IS sequence are
underlined. It is anticipated that, as with the AD2 sequence shown
in SEQ ID NO: 18, the AD moiety may also include the additional
N-terminal residues cysteine and glycine and C-terminal residues
glycine and cysteine.
TABLE-US-00011 SuperAKAP-IS (SEQ ID NO: 64) QIEYVAKQIVDYAIHQA
Alternative AKAP sequences (SEQ ID NO: 65) QIEYKAKQIVDHAIHQA (SEQ
ID NO: 66) QIEYHAKQIVDHAIHQA (SEQ ID NO: 67) QIEYVAKQIVDHAIHQA
[0143] FIG. 2 of Gold et al. disclosed additional DDD-binding
sequences from a variety of AKAP proteins, shown below.
[0144] RII-Specific AKAPs
TABLE-US-00012 AKAP-KL (SEQ ID NO: 68) PLEYQAGLLVQNAIQQAI AKAP79
(SEQ ID NO: 69) LLIETASSLVKNAIQLSI AKAP-Lbc (SEQ ID NO: 70)
LIEEAASRIVDAVIEQVK
[0145] RI-Specific AKAPs
TABLE-US-00013 AKAPce (SEQ ID NO: 71) ALYQFADRFSELVISEAL RIAD (SEQ
ID NO: 72) LEQVANQLADQIIKEAT PV38 (SEQ ID NO: 73)
FEELAWKIAKMIWSDVF
[0146] Dual-Specificity AKAPs
TABLE-US-00014 AKAP7 (SEQ ID NO: 74) ELVRLSKRLVENAVLKAV MAP2D (SEQ
ID NO: 75) TAEEVSARIVQVVTAEAV DAKAP1 (SEQ ID NO: 76)
QIKQAAFQLISQVILEAT DAKAP2 (SEQ ID NO: 77) LAWKIAKMIVSDVMQQ
[0147] Stokka et al. (2006, Biochem J 400:493-99) also developed
peptide competitors of AKAP binding to PKA, shown in SEQ ID
NO:78-80. The peptide antagonists were designated as Ht31 (SEQ ID
NO:78), RIAD (SEQ ID NO:79) and PV-38 (SEQ ID NO:80). The Ht-31
peptide exhibited a greater affinity for the RII isoform of PKA,
while the RIAD and PV-38 showed higher affinity for RI.
TABLE-US-00015 Ht31 (SEQ ID NO: 78) DLIEEAASRIVDAVIEQVKAAGAY RIAD
(SEQ ID NO: 79) LEQYANQLADQIIKEATE PV-38 (SEQ ID NO: 80)
FEELAWKIAKMIWSDVFQQC
[0148] Hundsruckcr et al. (2006, Biochem J 396:297-306) developed
still other peptide competitors for AKAP binding to PKA, with a
binding constant as low as 0.4 nM to the DDD of the RII form of
PKA. The sequences of various AKAP antagonistic peptides are
provided in Table 1 of Hundsrucker et al., reproduced in Table 4
below. AKAPIS represents a synthetic RII subunit-binding peptide.
All other peptides are derived from the RII-binding domains of the
indicated AKAPs.
TABLE-US-00016 TABLE 4 AKAP Peptide sequences Peptide Sequence
AKAPIS QIEYLAKQIVDNAIQQA (SEQ ID NO: 17) AKAPIS-P QIEYLAKQIPDNAIQQA
(SEQ ID NO: 81) Ht31 KGADLIEEAASRIVDAVIEQVKAAG (SEQ ID NO: 82)
Ht31-P KGADLIEEAASRIPDAPIEQVKAAG (SEQ ID NO: 83)
AKAP7.delta.-wt-pep PEDAELVRLSKRLVENAVLKAVQQY (SEQ ID NO: 84)
AKAP7.delta.-L304T-pep PEDAELVRTSKRLVENAVLKAVQQY (SEQ ID NO: 85)
AKAP7.delta.-L308D-pep PEDAELVRLSKRDVENAVLKAVQQY (SEQ ID NO: 86)
AKAP7.delta.-P-pep PEDAELVRLSKRLPENAVLKAVQQY (SEQ ID NO: 87)
AKAP7.delta.-PP-pep PEDAELVRLSKRLPENAPLKAVQQY (SEQ ID NO: 88)
AKAP7.delta.-L314E-pep PEDAELVRLSKRLVENAVEKAVQQY (SEQ ID NO: 89)
AKAP1-pep EEGLDRNEEIKRAAFQIISQVISEA (SEQ ID NO: 90) AKAP2-pep
LVDDPLEYQAGLLVQNAIQQAIAEQ (SEQ ID NO: 91) AKAP5-pep
QYETLLIETASSLVKNAIQLSIEQL (SEQ ID NO: 92) AKAP9-pep
LEKQYQEQLEEEVAKVIVSMSIAFA (SEQ ID NO: 93) AKAP10-pep
NTDEAQEELAWKIAKMIVSDIMQQA (SEQ ID NO: 94) AKAP11-pep
VNLDKKAVLAEKIVAEAIEKAEREL (SEQ ID NO: 95) AKAP12-pep
NGILELETKSSKLVQNIIQTAVDQF (SEQ ID NO: 96) AKAP14-pep
TQDKNYEDELTQVALALVEDVINYA (SEQ ID NO: 97) Rab32-pep
ETSAKDNINIEEAARFLVEKILVNH (SEQ ID NO: 98)
[0149] Residues that were highly conserved among the AD domains of
different AKAP proteins are indicated below by underlining with
reference to the AKAP IS sequence (SEQ ID NO: 17). The residues are
the same as observed by Alto et al. (2003), with the addition of
the C-terminal alanine residue. (See FIG. 4 of Hundsrucker et al.
(2006), incorporated herein by reference.) The sequences of peptide
antagonists with particularly high affinities for the RII DDD
sequence were those of AKAP-IS, AKAP7.delta.-wt-pep,
AKAP7.delta.-L304T-pep and AKAP7.delta.-L308D-pep.
TABLE-US-00017 AKAP-IS (SEQ ID NO: 17) QIEYLAKQIVDNAIQQA
[0150] Carr et al. (2001, J Biol Chem 276:17332-38) examined the
degree of sequence homology between different AKAP-binding DDD
sequences from human and non-human proteins and identified residues
in the DDD sequences that appeared to be the most highly conserved
among different DDD moieties. These are indicated below by
underlining with reference to the human PKA RII.alpha. DDD sequence
of SEQ ID NO: 15. Residues that were particularly conserved are
further indicated by italics. The residues overlap with, but are
not identical to those suggested by Kinderman et al. (2006) to be
important for binding to AKAP proteins. The skilled artisan will
realize that in designing sequence variants of DDD, it would be
most preferred to avoid changing the most conserved residues
(italicized), and it would be preferred to also avoid changing the
conserved residues (underlined), while conservative amino acid
substitutions may be considered for residues that are neither
underlined nor italicized.
TABLE-US-00018 (SEQ ID NO: 15)
SHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRLREARA
[0151] A modified set of conservative amino acid substitutions for
the DDD1 (SEQ ID NO:15) sequence, based on the data of Carr et al.
(2001) is shown in Table 5. Even with this reduced set of
substituted sequences, there are over 65,000 possible alternative
DDD moiety sequences that may be produced, tested and used by the
skilled artisan without undue experimentation. The skilled artisan
could readily derive such alternative DDD amino acid sequences as
disclosed above for Table 2 and Table 3.
TABLE-US-00019 TABLE 5 Conservative Amino Acid Substitutions in
DDD1 (SEQ ID NO: 15). Consensus sequence disclosed as SEQ ID NO:
133. S H I Q P T E O V T N S I L A Q P V E V E T R R E A A N I D S
K K L L L I I A V V
[0152] The skilled artisan will realize that these and other amino
acid substitutions in the DDD or AD amino acid sequences may be
utilized to produce alternative species within the genus of AD or
DDD moieties, using techniques that are standard in the field and
only routine experimentation.
[0153] Amino Acid Substitutions
[0154] In various embodiments, the disclosed methods and
compositions may involve production and use of proteins or peptides
with one or more substituted amino acid residues. For example, the
DDD and/or AD sequences used to make DNL constructs may be modified
as discussed above.
[0155] The skilled artisan will be aware that, in general, amino
acid substitutions typically involve the replacement of an amino
acid with another amino acid of relatively similar properties
(i.e., conservative amino acid substitutions). The properties of
the various amino acids and effect of amino acid substitution on
protein structure and function have been the subject of extensive
study and knowledge in the art.
[0156] For example, the hydropathic index of amino acids may be
considered (Kyte & Doolittle, 1982, J. Mol. Biol.,
157:105-132). The relative hydropathic character of the amino acid
contributes to the secondary structure of the resultant protein,
which in turn defines the interaction of the protein with other
molecules. Each amino acid has been assigned a hydropathic index on
the basis of its hydrophobicity and charge characteristics (Kyte
& Doolittle, 1982), these are: isoleucine (+4.5); valine
(+4.2); leucine (+3.8); phenylalanine (+2.8); cysteine/cystine
(+2.5); methionine (+1.9); alanine (+1.8); glycine (-0.4);
threonine (-0.7); serine (-0.8); tryptophan (-0.9); tyrosine
(-1.3); proline (-1.6): histidine (-3.2); glutamate (-3.5);
glutamine (-3.5); aspartate (-3.5); asparagine (-3.5); lysine
(-3.9); and arginine (-4.5). In making conservative substitutions,
the use of amino acids whose hydropathic indices are within .+-.2
is preferred, within .+-.1 are more preferred, and within .+-.0.5
are even more preferred.
[0157] Amino acid substitution may also take into account the
hydrophilicity of the amino acid residue (e.g., U.S. Pat. No.
4,554,101). Hydrophilicity values have been assigned to amino acid
residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0);
glutamate (+3.0); serine (+0.3); asparagine (+0.2); glutamine
(+0.2); glycine (0); threonine (-0.4); proline (-0.5.+-0.1);
alanine (-0.5); histidine (-0.5); cysteine (-1.0): methionine
(-1.3); valine (-1.5); leucine (-1.8); isoleucine (-1.8); tyrosine
(-2.3); phenylalanine (-2.5); tryptophan (-3.4). Replacement of
amino acids with others of similar hydrophilicity is preferred.
[0158] Other considerations include the size of the amino acid side
chain. For example, it would generally not be preferred to replace
an amino acid with a compact side chain, such as glycine or serine,
with an amino acid with a bulky side chain, e.g., tryptophan or
tyrosine. The effect of various amino acid residues on protein
secondary structure is also a consideration. Through empirical
study, the effect of different amino acid residues on the tendency
of protein domains to adopt an alpha-helical, beta-sheet or reverse
turn secondary structure has been determined and is known in the
art (see, e.g., Chou & Fasman, 1974, Biochemistry, 13:222-245;
1978, Ann. Rev. Biochem., 47: 251-276; 1979, Biophys. J.,
26:367-384).
[0159] Based on such considerations and extensive empirical study,
tables of conservative amino acid substitutions have been
constructed and are known in the art. For example: arginine and
lysine; glutamate and aspartate; serine and threonine; glutamine
and asparagine; and valine, leucine and isoleucine. Alternatively:
Ala (A) leu, ile, val; Arg (R) gln, asn, lys; Asn (N) his, asp,
lys, arg, gln; Asp (D) asn, glu; Cys (C) ala, ser; Gin (Q) glu,
asn; Glu (E) gin, asp; Gly (G) ala; His (H) asn, gln, lys, arg; Ile
(I) val, met, ala, phe, leu; Leu (L) val, met, ala, phe, ile; Lys
(K) gln, asn, arg; Met (M) phe, ile, leu; Phe (F) leu, val, ile,
ala, tyr; Pro (P) ala; Ser (S), thr, Thr (T) ser, Trp (W) phe, tyr;
Tyr (Y) trp, phe, thr, ser, Val (V) ile, leu, met, phe, ala.
[0160] Other considerations for amino acid substitutions include
whether or not the residue is located in the interior of a protein
or is solvent exposed. For interior residues, conservative
substitutions would include: Asp and Asn; Ser and Thr; Ser and Ala;
Thr and Ala; Ala and Gly; Ile and Val; Val and Leu; Leu and Ile;
Leu and Met; Phe and Tyr; Tyr and Trp. (See, e.g., PROWL website at
rockefeller.edu) For solvent exposed residues, conservative
substitutions would include: Asp and Asn; Asp and Glu; Glu and Gin;
Glu and Ala; Gly and Asn; Ala and Pro; Ala and Gly; Ala and Ser;
Ala and Lys; Ser and Thr; Lys and Arg; Val and Leu; Leu and Ile;
Ile and Val; Phe and Tyr. (Id.) Various matrices have been
constructed to assist in selection of amino acid substitutions,
such as the PAM250 scoring matrix, Dayhoff matrix, Grantham matrix,
McLachlan matrix, Doolittle matrix, Henikoff matrix, Miyata matrix,
Fitch matrix, Jones matrix, Rao matrix, Levin matrix and Risler
matrix (Idem.)
[0161] In determining amino acid substitutions, one may also
consider the existence of intermolecular or intramolecular bonds,
such as formation of ionic bonds (salt bridges) between positively
charged residues (e.g., His, Arg, Lys) and negatively charged
residues (e.g., Asp, Glu) or disulfide bonds between nearby
cysteine residues.
[0162] Methods of substituting any amino acid for any other amino
acid in an encoded protein sequence are well known and a matter of
routine experimentation for the skilled artisan, for example by the
technique of site-directed mutagenesis or by synthesis and assembly
of oligonucleotides encoding an amino acid substitution and
splicing into an expression vector construct.
[0163] Immunoconjuates
[0164] In certain embodiments, an antibody or antibody fragment may
be directly attached to one or more therapeutic agents to form an
immunoconjugate. Therapeutic agents may be attached, for example to
reduced SH groups and/or to carbohydrate side chains. A therapeutic
agent can be attached at the hinge region of a reduced antibody
component via disulfide bond formation. Alternatively, such agents
can be attached using a heterobifunctional cross-linker, such as
N-succinyl 3-(2-pyridyldithio)propionate (SPDP). Yu et al., Int. J.
Cancer 56: 244 (1994). General techniques for such conjugation are
well-known in the art. See, for example, Wong, CHEMISTRY OF PROTEIN
CONJUGATION AND CROSS-LINKING (CRC Press 1991); Upeslacis et al.,
"Modification of Antibodies by Chemical Methods," in MONOCLONAL
ANTIBODIES: PRINCIPLES AND APPLICATIONS, Birch et al. (eds.), pages
187-230 (Wiley-Liss, Inc. 1995); Price, "Production and
Characterization of Synthetic Peptide-Derived Antibodies," in
MONOCLONAL ANTIBODIES: PRODUCTION, ENGINEERING AND CLINICAL
APPLICATION, Ritter et al. (eds.), pages 60-84 (Cambridge
University Press 1995). Alternatively, the therapeutic agent can be
conjugated via a carbohydrate moiety in the Fe region of the
antibody.
[0165] Methods for conjugating functional groups to antibodies via
an antibody carbohydrate moiety are well-known to those of skill in
the art. See, for example, Shih et al., Int. J. Cancer 41: 832
(1988); Shih et al, Int. J. Cancer 46: 1101 (1990); and Shih et
al., U.S. Pat. No. 5,057,313, the Examples section of which is
incorporated herein by reference. The general method involves
reacting an antibody having an oxidized carbohydrate portion with a
carrier polymer that has at least one free amine function. This
reaction results in an initial Schiff base (imine) linkage, which
can be stabilized by reduction to a secondary amine to form the
final conjugate.
[0166] The Fc region may be absent if the antibody component of the
immunoconjugate is an antibody fragment. However, it is possible to
introduce a carbohydrate moiety into the light chain variable
region of a full length antibody or antibody fragment. See, for
example, Leung et al., J. Immunol. 154: 5919 (1995); U.S. Pat. Nos.
5,443,953 and 6,254,868, the Examples section of which is
incorporated herein by reference. The engineered carbohydrate
moiety is used to attach the therapeutic or diagnostic agent.
[0167] An alternative method for attaching therapeutic agents to an
antibody or fragment involves use of click chemistry reactions. The
click chemistry approach was originally conceived as a method to
rapidly generate complex substances by joining small subunits
together in a modular fashion. (See, e.g., Kolb et al., 2004, Angew
Chem Int Ed 40:3004-31; Evans, 2007, Aust J Chem 60:384-95.)
Various forms of click chemistry reaction are known in the art,
such as the Huisgen 1,3-dipolar cycloaddition copper catalyzed
reaction (Tornoe et al., 2002, J Organic Chem 67:3057-64), which is
often referred to as the "click reaction." Other alternatives
include cycloaddition reactions such as the Diels-Alder,
nucleophilic substitution reactions (especially to small strained
rings like epoxy and aziridine compounds), carbonyl chemistry
formation of urea compounds and reactions involving carbon-carbon
double bonds, such as alkynes in thiol-yne reactions.
[0168] The azide alkyne Huisgen cycloaddition reaction uses a
copper catalyst in the presence of a reducing agent to catalyze the
reaction of a terminal alkyne group attached to a first molecule.
In the presence of a second molecule comprising an azide moiety,
the azide reacts with the activated alkyne to form a
1,4-disubstituted 1,2,3-triazole. The copper catalyzed reaction
occurs at room temperature and is sufficiently specific that
purification of the reaction product is often not required.
(Rostovstev et al., 2002, Angew Chem Int Ed 41:2596; Tomoe et al.,
2002, J Org Chem 67:3057.) The azide and alkyne functional groups
are largely inert towards biomolecules in aqueous medium, allowing
the reaction to occur in complex solutions. The triazole formed is
chemically stable and is not subject to enzymatic cleavage, making
the click chemistry product highly stable in biological systems.
Although the copper catalyst is toxic to living cells, the
copper-based click chemistry reaction may be used in vitro for
immunoconjugate formation.
[0169] A copper-free click reaction has been proposed for covalent
modification of biomolecules. (See, e.g., Agard et al., 2004, J Am
Chem Soc 126:15046-47.) The copper-free reaction uses ring strain
in place of the copper catalyst to promote a [3+2] azide-alkyne
cycloaddition reaction (Id.) For example, cyclooctyne is an
8-carbon ring structure comprising an internal alkyne bond. The
closed ring structure induces a substantial bond angle deformation
of the acetylene, which is highly reactive with azide groups to
form a triazole. Thus, cyclooctyne derivatives may be used for
copper-free click reactions (Id.)
[0170] Another type of copper-free click reaction was reported by
Ning et al. (2010. Angew Chem Int Ed 49:3065-68), involving
strain-promoted alkyne-nitrone cycloaddition. To address the slow
rate of the original cyclooctyne reaction, electron-withdrawing
groups are attached adjacent to the triple bond (Id.) Examples of
such substituted cyclooctynes include difluorinated cyclooctynes,
4-dibenzocyclooctynol and azacyclooctyne (Id.) An alternative
copper-free reaction involved strain-promoted akyne-nitrone
cycloaddition to give N-alkylated isoxazolines (Id.) The reaction
was reported to have exceptionally fast reaction kinetics and was
used in a one-pot three-step protocol for site-specific
modification of peptides and proteins (Id.) Nitrones were prepared
by the condensation of appropriate aldehydes with
N-methylhydroxylamine and the cycloaddition reaction took place in
a mixture of acetonitrile and water (Id.) These and other known
click chemistry reactions may be used to attach therapeutic agents
to antibodies in vitro.
[0171] The specificity of the click chemistry reaction may be used
as a substitute for the antibody-hapten binding interaction used in
pretargeting with bispecific antibodies. In this alternative
embodiment, the specific reactivity of e.g., cyclooctyne moieties
for azide moieties or alkyne moieties for nitrone moieties may be
used in an in vivo cycloaddition reaction. An antibody, antibody
fragment or antibody-based complex is activated by incorporation of
a substituted cyclooctyne, an azide or a nitrone moiety. A
targetable construct is labeled with one or more diagnostic or
therapeutic agents and a complementary reactive moiety. I.e., where
the antibody comprises a cyclooctyne, the targetable construct will
comprise an azide; where the antibody comprises a nitrone, the
targetable construct will comprise an alkyne, etc. The activated
antibody or fragment is administered to a subject and allowed to
localize to a targeted cell, tissue or pathogen, as disclosed for
pretargeting protocols. The reactive labeled targetable construct
is then administered. Because the cyclooctyne, nitrone or azide on
the targetable construct is unreactive with endogenous biomolecules
and highly reactive with the complementary moiety on the antibody,
the specificity of the binding interaction results in the highly
specific binding of the targetable construct to the
tissue-localized antibody.
[0172] Therapeutic Agents
[0173] A wide variety of therapeutic reagents can be administered
concurrently or sequentially with the subject anti-CD22 antibodies
or antibody combinations. For example, drugs, toxins,
oligonucleotides, immunomodulators, cytokine or chemokine
inhibitors, proapoptotic agents, tyrosine kinase inhibitors,
sphingosine inhibitors, hormones, hormone antagonists, enzymes,
enzyme inhibitors, radionuclides, angiogenesis inhibitors, other
antibodies or fragments thereof, etc. The therapeutic agents
recited here are those agents that also are useful for
administration separately with an antibody or fragment thereof as
described above. Therapeutic agents include, for example, cytotoxic
agents such as vinca alkaloids, anthracyclines, gemcitabine,
epipodophyllotoxins, taxanes, antimetabolites, alkylating agents,
antibiotics, SN-38. COX-2 inhibitors, antimitotics, anti-angiogenic
and pro-apoptotic agents, particularly doxorubicin, methotrexate,
taxol. CPT-11, camptothecins, proteosome inhibitors, mTOR
inhibitors, HDAC inhibitors, tyrosine kinase inhibitors, and
others.
[0174] Other useful cytotoxic agents include nitrogen mustards,
alkyl sulfonates, nitrosoureas, triazenes, folic acid analogs,
COX-2 inhibitors, antimetabolites, pyrimidine analogs, purine
analogs, platinum coordination complexes, mTOR inhibitors, tyrosine
kinase inhibitors, proteosome inhibitors, HDAC inhibitors,
camptothecins, hormones, and the like. Suitable cytotoxic agents
are described in REMINGTON'S PHARMACEUTICAL SCIENCES, 19th Ed.
(Mack Publishing Co. 1995), and in GOODMAN AND GILMAN'S THE
PHARMACOLOGICAL BASIS OF THERAPEUTICS, 7th Ed. (MacMillan
Publishing Co. 1985), as well as revised editions of these
publications.
[0175] In a preferred embodiment, conjugates of camptothecins and
related compounds, such as SN-38, may be conjugated to an antibody,
for example as disclosed in U.S. Pat. No. 7,591,994, the Examples
section of which is incorporated herein by reference.
[0176] The therapeutic agent may be selected from the group
consisting of aplidin, azaribine, anastrozole, azacytidine,
bleomycin, bortezomib, bryostatin-1, busulfan, calicheamycin,
camptothecin, 10-hydroxycamptothecin, carmustine, celebrex,
chlorambucil, cisplatin, irinotecan (CPT-11), SN-38, carboplatin,
cladribine, cyclophosphamide, cytarabine, dacarbazine, docetaxel,
dactinomycin, daunomycin glucuronide, daunorubicin, dexamethasone,
diethylstilbestrol, doxorubicin, doxorubicin glucuronide,
epirubicin glucuronide, ethinyl estradiol, estramustine, etoposide,
etoposide glucuronide, etoposide phosphate, floxuridine (FUdR),
3',5'-O-dioleoyl-FudR (FUdR-dO), fludarabine, flutamide,
fluorouracil, fluoxymesterone, gemcitabine, hydroxyprogesterone
caproate, hydroxyurea, idarubicin, ifosfamide, L-asparaginase,
leucovorin, lomustine, mechlorethamine, medroprogesterone acetate,
egestrol acetate, melphalan, mercaptopurine, 6-mercaptopurine,
methotrexate, mitoxantrone, mithramycin, mitomycin, mitotane,
phenyl butyrate, prednisone, procarbazine, paclitaxel, pentostatin,
PSI-341, semustine streptozocin, tamoxifen, taxanes, taxol,
testosterone propionate, thalidomide, thioguanine, thiotepa,
teniposide, topotecan, uracil mustard, velcade, vinblastine,
vinorelbine, vincristine, ricin, abrin, ribonuclease, onconase,
rapLR1, DNase I, Staphylococcal enterotoxin-A, pokeweed antiviral
protein, gelonin, diphtheria toxin, Pseudomonas exotoxin, and
Pseudomonas endotoxin.
[0177] A toxin can be of animal, plant or microbial origin. A
toxin, such as Pseudomonas exotoxin, may also be complexed to or
form the therapeutic agent portion of an immunoconjugate. Other
toxins include ricin, abrin, ribonuclease (RNase), DNase 1,
Staphylococcal enterotoxin-A, pokeweed antiviral protein, onconase,
gelonin, diphtheria toxin, Pseudomonas exotoxin, and Pseudomonas
endotoxin. See, for example, Pastan et al., Cell 47:641 (1986),
Goldenberg, CA-A Cancer Journal for Clinicians 44:43 (1994),
Sharkey and Goldenberg, CA-A Cancer Journal for Clinicians 56:226
(2006). Additional toxins suitable for use are known to those of
skill in the art and are disclosed in U.S. Pat. No. 6,077,499, the
Examples section of which is incorporated herein by reference.
[0178] The therapeutic agent may be an enzyme selected from the
group consisting of malate dehydrogenase, staphylococcal nuclease,
delta-V-steroid isomerase, yeast alcohol dehydrogenase,
alpha-glycerophosphate dehydrogenase, triose phosphate isomerase,
horseradish peroxidase, alkaline phosphatase, asparaginase, glucose
oxidase, beta-galactosidase, ribonuclease, urease, catalase,
glucose-6-phosphate dehydrogenase, glucoamylase and
acetylcholinesterase.
[0179] As used herein, the term "immunomodulator" includes
cytokines, lymphokines, monokines, stem cell growth factors,
lymphotoxins, hematopoietic factors, colony stimulating factors
(CSF), interferons (IFN), parathyroid hormone, thyroxine, insulin,
proinsulin, relaxin, prorelaxin, follicle stimulating hormone
(FSH), thyroid stimulating hormone (TSH), luteinizing hormone (LH),
hepatic growth factor, prostaglandin, fibroblast growth factor,
prolactin, placental lactogen, OB protein, transforming growth
factor (TGF), TGF-.alpha., TGF-.beta., insulin-like growth factor
(IGF), erythropoietin, thrombopoietin, tumor necrosis factor (TNF),
TNF-.alpha., TNF-.beta., mullerian-inhibiting substance, mouse
gonadotropin-associated peptide, inhibin, activin, vascular
endothelial growth factor, integrin, interleukin (IL),
granulocyte-colony stimulating factor (G-CSF), granulocyte
macrophage-colony stimulating factor (GM-CSF), interferon-.alpha.,
interferon-.beta., interferon-.gamma., S1 factor, IL-1, IL-1cc,
IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11,
IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18 IL-21, IL-23,
IL-25, LIF, kit-ligand, FLT-3, angiostatin, thrombospondin,
endostatin, and the like.
[0180] Exemplary anti-angiogenic agents may include angiostatin,
endostatin, vasculostatin, canstatin, maspin, anti-VEGF binding
molecules, anti-placental growth factor binding molecules, or
anti-vascular growth factor binding molecules.
[0181] In certain embodiments, the antibody or complex may comprise
one or more chelating moieties, such as NOTA, DOTA, DTPA, TETA,
Tscg-Cys, or Tsca-Cys. In certain embodiments, the chelating moiety
may form a complex with a therapeutic or diagnostic cation, such as
Group II, Group III, Group IV, Group V, transition, lanthanide or
actinide metal cations, Tc, Re, Bi, Cu, As, Ag, Au, At, or Pb.
[0182] The antibody or fragment thereof may be administered as an
immunoconjugate comprising one or more radioactive isotopes useful
for treating diseased tissue. Particularly useful therapeutic
radionuclides include, but are not limited to .sup.111In,
.sup.177Lu, .sup.212Bi, .sup.213Bi, .sup.211At, .sup.62Cu,
.sup.64Cu, .sup.67Cu, .sup.90Y, .sup.125I, .sup.131I, .sup.32P,
.sup.32P, .sup.33P, .sup.47Sc, .sup.111Ag, .sup.67Ga, .sup.412Pr,
.sup.153Sm, .sup.161Tb, .sup.166Dy, .sup.166Ho, .sup.186Re,
.sup.188Re, .sup.189Re, .sup.212Pb, .sup.223Ra, .sup.225Ac,
.sup.59Fe, .sup.75Se, .sup.77As, .sup.89Sr, .sup.99Mo, .sup.105Rh,
.sup.109Pd, .sup.143Pr, .sup.149Pm, .sup.169Er, .sup.194Ir,
.sup.198Au, .sup.199Au, and .sup.211Pb. The therapeutic
radionuclide preferably has a decay energy in the range of 20 to
6,000 keV, preferably in the ranges 60 to 200 keV for an Auger
emitter, 100-2,500 keV for a beta emitter and 4,000-6,000 keV for
an alpha emitter. Maximum decay energies of useful
beta-particle-emitting nuclides are preferably 20-5,000 keV, more
preferably 100-4.000 keV and most preferably 500-2,500 keV. Also
preferred are radionuclides that substantially decay with
Auger-emitting particles. For example, Co-58, Ga-67, Br-80m,
Tc-99m, Rh-103m, Pt-109, In-111, Sb-119, I-125, Ho-161, Os-189m and
Ir-192. Decay energies of useful beta-particle-emitting nuclides
are preferably <1,000 keV, more preferably <100 keV, and most
preferably <70 keV. Also preferred are radionuclides that
substantially decay with generation of alpha-particles. Such
radionuclides include, but are not limited to: Dy-152, At-211,
Bi-212, Ra-223, Rn-219, Po-215, Bi-211, Ac-225, Fr-221, At-217,
Bi-213 and Fm-255. Decay energies of useful alpha-particle-emitting
radionuclides are preferably 2,000-10,000 keV, more preferably
3,000-8,000 keV, and most preferably 4,000-7,000 keV.
[0183] Additional potential therapeutic radioisotopes include
.sup.11C, .sup.13N, .sup.15O, .sup.75Br, .sup.198Au, .sup.224Ac,
.sup.126I, .sup.133I, .sup.77Br, .sup.113mIn, .sup.95Ru, .sup.97Ru,
.sup.103Ru, .sup.105Ru, .sup.107Hg, .sup.203Hg, .sup.121mTe,
.sup.122mTe, .sup.125mTe, .sup.165Tm, .sup.167Tm, .sup.168Tm,
.sup.197Pt, .sup.109Pd, .sup.105Rh, .sup.142Pr, .sup.143Pr,
.sup.161Tb, .sup.166Ho, .sup.119Au, .sup.57Co, .sup.58Co,
.sup.51Cr, .sup.59Fe, .sup.75Se, .sup.201Tl, .sup.225Ac, .sup.76Br,
.sup.169Yb, and the like.
[0184] Interference RNA
[0185] In certain preferred embodiments the therapeutic agent may
be a siRNA or interference RNA species. The siRNA, interference RNA
or therapeutic gene may be attached to a carrier moiety that is
conjugated to an antibody or fragment thereof. A variety of carrier
moieties for siRNA have been reported and any such known carrier
may be incorporated into a therapeutic antibody for use.
Non-limiting examples of carriers include protamine (Rossi, 2005,
Nat Biotech 23:682-84; Song et al., 2005, Nat Biotech 23:709-17);
dendrimers such as PAMAM dendrimers (Pan et al., 2007, Cancer Res.
67:8156-8163); polyethylenimine (Schiffelers et al., 2004, Nucl
Acids Res 32:e149); polypropyleneimine (Taratula et al., 2009, J
Control Release 140:284-93); polylysine (Inoue et al., 2008, J
Control Release 126:59-66); histidine-containing reducible
polycations (Stevenson et al., 2008, J Control Release 130:46-56);
histone H1 protein (Haberland et al., 2009, Mol Biol Rep
26:1083-93); cationic comb-type copolymers (Sato et al., 2007, J
Control Release 122:209-16); polymeric micelles (U.S. Patent
Application Publ. No. 20100121043); and chitosan-thiamine
pyrophosphate (Rojanarata et al., 2008, Pharm Res 25:2807-14). The
skilled artisan will realize that in general, polycationic proteins
or polymers are of use as siRNA carriers. The skilled artisan will
further realize that siRNA carriers can also be used to carry other
oligonucleotide or nucleic acid species, such as anti-sense
oligonucleotides or short DNA genes.
[0186] Known siRNA species of potential use include those specific
for IKK-gamma (U.S. Pat. No. 7,022,828); VEGF, Flt-1 and Flk-1/KDR
(U.S. Pat. No. 7,148,342); Bcl2 and EGFR (U.S. Pat. No. 7,541,453);
CDC20 (U.S. Pat. No. 7,550,572); transducin (beta)-like 3 (U.S.
Pat. No. 7,576,196); K-ras (U.S. Pat. No. 7,576,197); carbonic
anhydrase II (U.S. Pat. No. 7,579,457); complement component 3
(U.S. Pat. No. 7,582,746); interleukin-1 receptor-associated kinase
4 (IRAK4) (U.S. Pat. No. 7,592,443); survivin (U.S. Pat. No.
7,608,7070); superoxide dismutase 1 (U.S. Pat. No. 7,632,938); MET
proto-oncogene (U.S. Pat. No. 7,632,939); amyloid beta precursor
protein (APP) (U.S. Pat. No. 7,635,771); IGF-1R (U.S. Pat. No.
7,638,621); ICAM1 (U.S. Pat. No. 7,642,349); complement factor B
(U.S. Pat. No. 7,696,344); p53 (U.S. Pat. No. 7,781,575), and
apolipoprotein B (U.S. Pat. No. 7,795,421), the Examples section of
each referenced patent incorporated herein by reference.
[0187] Additional siRNA species are available from known commercial
sources, such as Sigma-Aldrich (St Louis, Mo.), Invitrogen
(Carlsbad, Calif.), Santa Cruz Biotechnology (Santa Cruz, Calif.),
Ambion (Austin, Tex.), Dharmacon (Thermo Scientific, Lafayette,
Colo.), Promega (Madison, Wis.), Mirus Bio (Madison, Wis.) and
Qiagen (Valencia, Calif.), among many others. Other publicly
available sources of siRNA species include the siRNAdb database at
the Stockholm Bioinformatics Centre, the MIT/ICBP siRNA Database,
the RNAi Consortium shRNA Library at the Broad Institute, and the
Probe database at NCBI. For example, there are 30,852 siRNA species
in the NCBI Probe database. The skilled artisan will realize that
for any gene of interest, either a siRNA species has already been
designed, or one may readily be designed using publicly available
software tools. Any such siRNA species may be delivered using the
subject antibodies, antibody fragments or antibody complexes.
[0188] Exemplary siRNA species known in the art are listed in Table
6. Although siRNA is delivered as a double-stranded molecule, for
simplicity only the sense strand sequences are shown in Table
6.
TABLE-US-00020 TABLE 6 Exemplary siRNA Sequences Target Sequence
SEQ ID NO VEGF R2 AATGCGGCGGTGGTGACAGTA SEQ ID NO: 99 VEGF R2
AAGCTCAGCACACAGAAAGAC SEQ ID NO: 100 CXCR4 UAAAAUCUUCCUGCCCACCdTdT
SEQ ID NO: 101 CXCR4 GGAAGCUGUUGGCUGAAAAdTdT SEQ ID NO: 102 PPARC1
AAGACCAGCCUCUUUGCCCAG SEQ ID NO: 103 Dynamin 2 GGACCAGGCAGAAAACGAG
SEQ ID NO: 104 Catenin CUAUCAGGAUGACGCGG SEQ ID NO: 105 E1A binding
protein UGACACAGGCAGGCUUGACUU SEQ ID NO: 106 Plasminogen
GGTGAAGAAGGGCGTCCAA SEQ ID NO: 107 activator K-ras
GATCCGTTGGAGCTGTTGGCGTAGTT SEQ ID NO: 108
CAAGAGACTCGCCAACAGCTCCAACT TTTGGAAA Sortilin 1 AGGTGGTGTTAACAGCAGAG
SEQ ID NO: 109 Apolipoprotein E AAGGTGGAGCAAGCGGTGGAG SEQ ID NO:
110 Apolipoprotein E AAGGAGTTGAAGGCCGACAAA SEQ ID NO: 111 Bcl-X
UAUGGAGCUGCAGAGGAUGdTdT SEQ ID NO: 112 Raf-1
TTTGAATATCTGTGCTGAGAACACA SEQ ID NO: 113 GTTCTCAGCACAGATATTCTTTTT
Heat shock AATGAGAAAAGCAAAAGGTGCCCTGTCTC SEQ ID NO: 114
transcription factor 2 IGFBP3 AAUCAUCAUCAAGAAAGGGCA SEQ ID NO: 115
Thioredoxin AUGACUGUCAGGAUGUUGCdTdT SEQ ID NO: 116 CD44
GAACGAAUCCUGAAGACAUCU SEQ ID NO: 117 MMP14
AAGCCTGGCTACAGCAATATGCCTGTCTC SEQ ID NO: 118 MAPKAPK2
UGACCAUCACCGAGUUUAUdTdT SEQ ID NO: 119 FGFR1 AAGTCGGACGCAACAGAGAAA
SEQ ID NO: 120 ERBB2 CUACCUUUCUACGGACGUGdTdT SEQ ID NO: 121 BCL2L1
CTGCCTAAGGCGGATTTGAAT SEQ ID NO: 122 ABL1 TTAUUCCUUCUUCGGGAAGUC SEQ
ID NO: 123 CEACAM1 AACCTTCTGGAACCCGCCCAC SEQ ID NO: 124 CD9
GAGCATCTTCGAGCAAGAA SEQ ID NO: 125 CD151 CATGTGGCACCGTTTGCCT SEQ ID
NO: 126 Caspase 8 AACTACCAGAAAGGTATACCT SEQ ID NO: 127 BRCA1
UCACAGUGUCCUUUAUGUAdTdT SEQ ID NO: 128 p53 GCAUGAACCGGAGGCCCAUTT
SEQ ID NO: 129 CEACAM6 CCGGACAGTTCCATGTATA SEQ ID NO: 130
[0189] The skilled artisan will realize that Table 6 represents a
very small sampling of the total number of siRNA species known in
the art, and that any such known siRNA may be utilized in the
claimed methods and compositions.
[0190] Immunotoxins Comprising Ranpirnase (Rap)
[0191] Ribonucleases, in particular, Rap (Lee, Exp Opin Biol Ther
2008; 8:813-27) and its more basic variant, amphinase (Ardelt et
al., Curr Pharm Biotechnol 2008:9:215-25), are potential anti-tumor
agents (Lee and Raines, Biodrugs 2008; 22:53-8). Rap is a
single-chain ribonuclease of 104 amino acids originally isolated
from the oocytes of Rana pipiens. Rap exhibits cytostatic and
cytotoxic effects on a variety of tumor cell lines in vitro, as
well as antitumor activity in vivo. The amphibian ribonuclease
enters cells via receptor-mediated endocytosis and once
internalized into the cytosol, selectively degrades tRNA, resulting
in inhibition of protein synthesis and induction of apoptosis.
[0192] Rap has completed a random/zed Phase IIIb clinical trial,
which compared the effectiveness of Rap plus doxorubicin with that
of doxorubicin alone in patients with unresectable malignant
mesothelioma, with the interim analysis showing that the MST for
the combination was 12 months, while that of the monotherapy was 10
months (Mutti and Gaudino, Oncol Rev 2008; 2:61-5). Rap can be
administered repeatedly to patients without an untoward immune
response, with reversible renal toxicity reported to be
dose-limiting (Mikulski et al., J Clin Oncol 2002; 20:274-81; Int J
Oncol 1993; 3:57-64).
[0193] Conjugation or fusion of Rap to a tumor-targeting antibody
or antibody fragment is a promising approach to enhance its
potency, as first demonstrated for LL2-onconase (Newton et al.,
Blood 2001; 97:528-35), a chemical conjugate comprising Rap and a
murine anti-CD22 monoclonal antibody (MAb), and subsequently for
2L-Rap-hLL1-.gamma.4P, a fusion protein comprising Rap and a
humanized anti-CD74 MAb (Stein et al., Blood 2004; 104:3705-1).
[0194] The method used to generate 2L-Rap-hLL1-.gamma.4P allowed us
to develop a series of structurally similar immunotoxins, referred
to in general as 2L-Rap-X, all of which consist of two Rap
molecules, each connected via a flexible linker to the N-terminus
of one L chain of an antibody of interest (X). We have also
generated another series of immunotoxins of the same design,
referred to as 2LRap(Q)-X, by substituting Rap with its
non-glycosylation form of Rap, designated as Rap(Q) to denote that
the potential glycosylation site at Asn69 is changed to Gin (or Q,
single letter code). For both series, we made the IgG as either
IgG1(.gamma.1) or IgG4(.gamma.4), and to prevent the formation of
IgG4 half molecules (Aalberse and Schuurman, Immunology 2002;
105:9-19), we converted the serine residue in the hinge region
(S228) of IgG4 to proline (.gamma.4P). A pyroglutamate residue at
the N-terminus of Rap is required for the RNase to be fully
functional (Liao et al., Nucleic Acids Res 2003:31:5247-55).
[0195] The skilled artisan will recognize that the cytotoxic RNase
moieties suitable for use in the present invention include
polypeptides having a native ranpirnase structure and all
enzymatically active variants thereof. These molecules
advantageously have an N-terminal pyroglutamic acid resides that
appears essential for RNase activity and are not substantially
inhibited by mammalian RNase inhibitors. Nucleic acid that encodes
a native cytotoxic RNase may be prepared by cloning and restriction
of appropriate sequences, or using DNA amplification with
polymerase chain reaction (PCR). The amino acid sequence of Rana
pipiens ranpimase can be obtained from Ardelt et al., J. Biol.
Chem., 256:245 (1991), and cDNA sequences encoding native
ranpirnase, or a conservatively modified variation thereof, can be
gene-synthesized by methods similar to the en bloc V-gene assembly
method used in hLL2 humanization. (Leung et al., Mol. Immunol., 32:
1413, 1995). Methods of making cytotoxic RNase variants are known
in the art and are within the skill of the routineer.
[0196] As described in the Examples below, Rap conjugates of
targeting antibodies may be made using the DNL technology. The DNL
Rap-antibody constructs show potent cytotoxic activity that can be
targeted to disease-associated cells.
[0197] Diagnostic Agents
[0198] In various embodiments, the antibodies, antibody fragments
or antibody complexes may be conjugated to, or may bind a
targetable construct comprising one or more diagnostic agents.
Diagnostic agents are preferably selected from the group consisting
of a radionuclide, a radiological contrast agent, a paramagnetic
ion, a metal, a fluorescent label, a chemiluminescent label, an
ultrasound contrast agent and a photoactive agent. Such diagnostic
agents are well known and any such known diagnostic agent may be
used. Non-limiting examples of diagnostic agents may include a
radionuclide such as .sup.18F, .sup.52Fe, .sup.110In, .sup.111In,
.sup.177Lu, .sup.18F, .sup.52Fe, .sup.62Cu, .sup.64Cu, .sup.67Cu,
.sup.67Ga, .sup.68Ga, .sup.86Y, .sup.90Y, .sup.89Zr, .sup.94mTc,
.sup.94Tc, .sup.99mTc, .sup.120I, .sup.123I, .sup.124I, .sup.125I,
.sup.131I, .sup.154-158Gd, .sup.32P, .sup.11C, .sup.13N, .sup.15O,
.sup.186Re, .sup.188Re, .sup.51Mn, .sup.52mMn, .sup.55Co,
.sup.72As, .sup.75Br, .sup.76Br, .sup.82mRb, .sup.83Sr, or other
gamma-, beta-, or positron-emitters.
[0199] Paramagnetic ions of use may include chromium (III),
manganese (II), iron (III), iron (II), cobalt (II), nickel (II),
copper (I), neodymium (III), samarium (III), ytterbium (III),
gadolinium (III), vanadium (II), terbium (III), dysprosium (III),
holmium (III) or erbium (II). Metal contrast agents may include
lanthanum (III), gold (III), lead (II) or bismuth (III).
[0200] Ultrasound contrast agents may comprise liposomes, such as
gas filled liposomes. Radiopaque diagnostic agents may be selected
from compounds, barium compounds, gallium compounds, and thallium
compounds. A wide variety of fluorescent labels are known in the
art, including but not limited to fluorescein isothiocyanate,
rhodamine, phycoerytherin, phycocyanin, allophycocyanin,
o-phthaldehyde and fluorescamine. Chemiluminescent labels of use
may include luminol, isoluminol, an aromatic acridinium ester, an
imidazole, an acridinium salt or an oxalate ester.
[0201] Methods of Therapeutic Treatment
[0202] The claimed methods and compositions are of use for treating
disease states, such as B-cell lymphomas or leukemias, autoimmune
disease or immune system dysfunction (e.g., graft-versus-host
disease). The methods may comprise administering a therapeutically
effective amount of an anti-CD22 antibody or fragment thereof or
immunoconjugate, either alone or in combination with one or more
other therapeutic agents, administered either concurrently or
sequentially. In preferred embodiments, as described in the
Examples below, the anti-CD22 antibody or fragment thereof may be
administered in the form of a DNL complex in combination with one
or more other therapeutic agents, such as a second antibody or
fragment thereof.
[0203] Multimodal therapies may include therapy with other
antibodies, such as antibodies against CD4, CD5, CD8, CD14, CD15,
CD19, CD20, CD21, CD22, CD23, CD25, CD33, CD37, CD38, CD40, CD40L,
CD46, CD52, CD54, CD74, CD80, CD126, CD138, B7, HM1.24, HLA-DR, an
angiogenesis factor, tenascin, VEGF, PIGF, ED-B fibronectin, an
oncogene, an oncogene product, NCA 66a-d, necrosis antigens, Ii,
IL-2, T101, TAC, IL-6, MUC-1, TRAIL-R1 (DR4) or TRAIL-R2 (DR5) in
the form of naked antibodies, fusion proteins, or as
immunoconjugates. Various antibodies of use are known to those of
skill in the art. See, for example, Ghetie et al., Cancer Res.
48:2610 (1988); Hekman et al., Cancer Immunol. Immunother. 32:364
(1991); Longo, Curr. Opin. Oncol. 8:353 (1996), U.S. Pat. Nos.
5,798,554; 6,187,287; 6,306,393; 6,676,924; 7,109,304; 7,151,164;
7,230,084; 7,230,085; 7,238,785; 7,238,786; 7,282,567; 7,300,655;
7,312,318; 7,612,180; 7,501,498; the Examples section of each of
which is incorporated herein by reference.
[0204] In another form of multimodal therapy, subjects may receive
therapeutic anti-CD22 antibodies or antibody combinations in
conjunction with standard chemotherapy. For example, "CVB" (1.5
g/m.sup.2 cyclophosphamide, 200-400 mg/m.sup.2 etoposide, and
150-200 mg/m.sup.2 carmustine) is a regimen used to treat
non-Hodgkin's lymphoma. Patti et al., Eur. J. Haematol. 51: 18
(1993). Other suitable combination chemotherapeutic regimens are
well-known to those of skill in the art. See, for example, Freedman
et al., "Non-Hodgkin's Lymphomas," in CANCER MEDICINE, VOLUME 2,
3rd Edition, Holland et al. (eds.), pages 2028-2068 (Lea &
Febiger 1993). As an illustration, first generation
chemotherapeutic regimens for treatment of intermediate-grade
non-Hodgkin's lymphoma (NHL) include C-MOPP (cyclophosphamide,
vincristine, procarbazine and prednisone) and CHOP
(cyclophosphamide, doxorubicin, vincristine, and prednisone). A
useful second generation chemotherapeutic regimen is m-BACOD
(methotrexate, bleomycin, doxorubicin, cyclophosphamide,
vincristine, dexamethasone and leucovorin), while a suitable third
generation regimen is MACOP-B (methotrexate, doxorubicin,
cyclophosphamide, vincristine, prednisone, bleomycin and
leucovorin). Additional useful drugs include phenyl butyrate,
bendamustine, and bryostatin-1.
[0205] Therapeutic antibodies or complexes, such as DNL complexes,
can be formulated according to known methods to prepare
pharmaceutically useful compositions, whereby the therapeutic
antibody complex is combined in a mixture with a pharmaceutically
suitable excipient. Sterile phosphate-buffered saline is one
example of a pharmaceutically suitable excipient. Other suitable
excipients are well-known to those in the art. See, for example,
Ansel et al., PHARMACEUTICAL DOSAGE FORMS AND DRUG DELIVERY
SYSTEMS, 5th Edition (Lea & Febiger 1990), and Gennaro (ed.),
REMINGTON'S PHARMACEUTICAL SCIENCES, 18th Edition (Mack Publishing
Company 1990), and revised editions thereof.
[0206] The therapeutic antibody complex can be formulated for
intravenous administration via, for example, bolus injection or
continuous infusion. Preferably, the therapeutic antibody complex
is infused over a period of less than about 4 hours, and more
preferably, over a period of less than about 3 hours. For example,
the first 25-50 mg could be infused within 30 minutes, preferably
even 15 min, and the remainder infused over the next 2-3 hrs.
Formulations for injection can be presented in unit dosage form,
e.g., in ampoules or in multi-dose containers, with an added
preservative. The compositions can take such forms as suspensions,
solutions or emulsions in oily or aqueous vehicles, and can contain
formulatory agents such as suspending, stabilizing and/or
dispersing agents. Alternatively, the active ingredient can be in
powder form for constitution with a suitable vehicle, e.g., sterile
pyrogen-free water, before use.
[0207] The therapeutic antibody complex may also be administered to
a mammal subcutaneously or even by other parenteral routes.
Moreover, the administration may be by continuous infusion or by
single or multiple boluses. In most preferred embodiments, the
therapeutic antibody or combination is administered subcutaneously
in a volume of 1, 2 or 3 ml and at a concentration of at least 80
mg/ml, at least 100 mg/ml, at least 125 mg/ml, at least 150 mg/ml,
at least 200 mg/ml, at least 250 mg/ml or at least 300 mg/ml.
Methods of antibody concentration and subcutaneous formulations are
disclosed in provisional U.S. Patent No. 61/509,850, filed Jul. 20,
2011, the Examples section of which (from paragraph 0133, page 48
to paragraph 0195, page 64) is incorporated herein by
reference.
[0208] More generally, the dosage of an administered therapeutic
antibody complex for humans will vary depending upon such factors
as the patient's age, weight, height, sex, general medical
condition and previous medical history. It may be desirable to
provide the recipient with a dosage of therapeutic antibody complex
that is in the range of from about 1 mg/kg to 25 mg/kg as a single
intravenous infusion, although a lower or higher dosage also may be
administered as circumstances dictate. A dosage of 1-20 mg/kg for a
70 kg patient, for example, is 70-1,400 mg, or 41-824 mg/m.sup.2
for a 1.7-m patient. The dosage may be repeated as needed, for
example, once per week for 4-10 weeks, once per week for 8 weeks,
or once per week for 4 weeks. It may also be given less frequently,
such as every other week for several months, or monthly or
quarterly for many months, as needed in a maintenance therapy.
[0209] Alternatively, a therapeutic antibody complex may be
administered as one dosage every 2 or 3 weeks, repeated for a total
of at least 3 dosages. Or, the therapeutic antibody complex may be
administered twice per week for 4-6 weeks. If the dosage is lowered
to approximately 200-300 mg/m.sup.2 (340 mg per dosage for a 1.7-m
patient, or 4.9 mg/kg for a 70 kg patient), it may be administered
once or even twice weekly for 4 to 10 weeks. Alternatively, the
dosage schedule may be decreased, namely every 2 or 3 weeks for 2-3
months. It has been determined, however, that even higher doses,
such as 20 mg/kg once weekly or once every 2-3 weeks can be
administered by slow i.v. infusion, for repeated dosing cycles. The
dosing schedule can optionally be repeated at other intervals and
dosage may be given through various parenteral routes, with
appropriate adjustment of the dose and schedule.
[0210] Additional pharmaceutical methods may be employed to control
the duration of action of the therapeutic immunoconjugate or naked
antibody. Control release preparations can be prepared through the
use of polymers to complex or adsorb the antibody. For example,
biocompatible polymers include matrices of poly(ethylene-co-vinyl
acetate) and matrices of a polyanhydride copolymer of a stearic
acid dimer and sebacic acid. Sherwood et al., Bio/Technology 10:
1446 (1992). The rate of release of an antibody from such a matrix
depends upon the molecular weight of the antibody, the amount of
antibody within the matrix, and the size of dispersed particles.
Saltzman et al., Biophys. J. 55: 163 (1989); Sherwood et al.,
supra. Other solid dosage forms are described in Ansel et al.,
PHARMACEUTICAL DOSAGE FORMS AND DRUG DELIVERY SYSTEMS, 5th Edition
(Lea & Febiger 1990), and Gennaro (ed.), REMINGTON'S
PHARMACEUTICAL SCIENCES, 18th Edition (Mack Publishing Company
1990), and revised editions thereof.
[0211] Cancer Therapy
[0212] In preferred embodiments, the anti-CD22 antibodies,
combinations or complexes are of use for therapy of cancer.
Examples of cancers include, but are not limited to, carcinoma,
lymphoma, glioblastoma, melanoma, sarcoma, and leukemia, myeloma,
or lymphoid malignancies. More particular examples of such cancers
are noted below and include: squamous cell cancer (e.g., epithelial
squamous cell cancer), Ewing sarcoma, Wilms tumor, astrocytomas,
lung cancer including small-cell lung cancer, non-small cell lung
cancer, adenocarcinoma of the lung and squamous carcinoma of the
lung, cancer of the peritoneum, hepatocellular cancer, gastric or
stomach cancer including gastrointestinal cancer, pancreatic
cancer, glioblastoma multiforme, cervical cancer, ovarian cancer,
liver cancer, bladder cancer, hepatoma, hepatocellular carcinoma,
neuroendocrine tumors, medullary thyroid cancer, differentiated
thyroid carcinoma, breast cancer, ovarian cancer, colon cancer,
rectal cancer, endometrial cancer or uterine carcinoma, salivary
gland carcinoma, kidney or renal cancer, prostate cancer, vulvar
cancer, anal carcinoma, penile carcinoma, as well as head-and-neck
cancer. The term "cancer" includes primary malignant cells or
tumors (e.g., those whose cells have not migrated to sites in the
subject's body other than the site of the original malignancy or
tumor) and secondary malignant cells or tumors (e.g., those arising
from metastasis, the migration of malignant cells or tumor cells to
secondary sites that are different from the site of the original
tumor).
[0213] Other examples of cancers or malignancies include, but are
not limited to: Acute Childhood Lymphoblastic Leukemia, Acute
Lymphoblastic Leukemia, Acute Lymphocytic Leukemia, Acute Myeloid
Leukemia, Adrenocortical Carcinoma, Adult (Primary) Hepatocellular
Cancer, Adult (Primary) Liver Cancer, Adult Acute Lymphocytic
Leukemia, Adult Acute Myeloid Leukemia, Adult Hodgkin's Lymphoma,
Adult Lymphocytic Leukemia, Adult Non-Hodgkin's Lymphoma, Adult
Primary Liver Cancer, Adult Soft Tissue Sarcoma, AIDS-Related
Lymphoma, AIDS-Related Malignancies, Anal Cancer, Astrocytoma, Bile
Duct Cancer, Bladder Cancer, Bone Cancer, Brain Stem Glioma, Brain
Tumors, Breast Cancer, Cancer of the Renal Pelvis and Ureter,
Central Nervous System (Primary) Lymphoma, Central Nervous System
Lymphoma, Cerebellar Astrocytoma, Cerebral Astrocytoma, Cervical
Cancer, Childhood (Primary) Hepatocellular Cancer, Childhood
(Primary) Liver Cancer, Childhood Acute Lymphoblastic Leukemia,
Childhood Acute Myeloid Leukemia, Childhood Brain Stem Glioma,
Childhood Cerebellar Astrocytoma, Childhood Cerebral Astrocytoma,
Childhood Extracranial Germ Cell Tumors, Childhood Hodgkin's
Disease, Childhood Hodgkin's Lymphoma, Childhood Hypothalamic and
Visual Pathway Glioma, Childhood Lymphoblastic Leukemia, Childhood
Medulloblastoma, Childhood Non-Hodgkin's Lymphoma. Childhood Pincal
and Supratentorial Primitive Neuroectodermal Tumors, Childhood
Primary Liver Cancer, Childhood Rhabdomyosarcoma, Childhood Soft
Tissue Sarcoma, Childhood Visual Pathway and Hypothalamic Glioma,
Chronic Lymphocytic Leukemia, Chronic Myelogenous Leukemia. Colon
Cancer, Cutaneous T-Cell Lymphoma, Endocrine Pancreas Islet Cell
Carcinoma, Endometrial Cancer, Ependymoma, Epithelial Cancer,
Esophageal Cancer, Ewing's Sarcoma and Related Tumors, Exocrine
Pancreatic Cancer, Extracranial Germ Cell Tumor, Extragonadal Germ
Cell Tumor, Extrahepatic Bile Duct Cancer, Eye Cancer, Female
Breast Cancer, Gaucher's Disease, Gallbladder Cancer, Gastric
Cancer, Gastrointestinal Carcinoid Tumor, Gastrointestinal Tumors,
Germ Cell Tumors, Gestational Trophoblastic Tumor, Hairy Cell
Leukemia, Head and Neck Cancer, Hepatocellular Cancer, Hodgkin's
Lymphoma, Hypergammaglobulinemia, Hypopharyngeal Cancer, Intestinal
Cancers, Intraocular Melanoma, Islet Cell Carcinoma, Islet Cell
Pancreatic Cancer, Kaposi's Sarcoma, Kidney Cancer, Laryngeal
Cancer, Lip and Oral Cavity Cancer, Liver Cancer, Lung Cancer,
Lymphoproliferative Disorders, Macroglobulinemia, Male Breast
Cancer, Malignant Mesothelioma, Malignant Thymoma, Medulloblastoma,
Melanoma, Mesothelioma, Metastatic Occult Primary Squamous Neck
Cancer, Metastatic Primary Squamous Neck Cancer, Metastatic
Squamous Neck Cancer, Multiple Myeloma, Multiple Myeloma/Plasma
Cell Neoplasm, Myelodysplastic Syndrome, Myelogenous Leukemia,
Myeloid Leukemia, Myeloproliferative Disorders, Nasal Cavity and
Paranasal Sinus Cancer, Nasopharyngeal Cancer, Neuroblastoma,
Non-Hodgkin's Lymphoma, Nonmelanoma Skin Cancer, Non-Small Cell
Lung Cancer, Occult Primary Metastatic Squamous Neck Cancer,
Oropharyngeal Cancer, Osteo-/Malignant Fibrous Sarcoma,
Osteosarcoma/Malignant Fibrous Histiocytoma, Osteosarcoma/Malignant
Fibrous Histiocytoma of Bone, Ovarian Epithelial Cancer, Ovarian
Germ Cell Tumor, Ovarian Low Malignant Potential Tumor, Pancreatic
Cancer, Paraproteinemias, Polycythemia vera, Parathyroid Cancer,
Penile Cancer, Pheochromocytoma, Pituitary Tumor, Primary Central
Nervous System Lymphoma, Primary Liver Cancer, Prostate Cancer,
Rectal Cancer, Renal Cell Cancer, Renal Pelvis and Ureter Cancer,
Retinoblastoma, Rhabdomyosarcoma, Salivary Gland Cancer,
Sarcoidosis Sarcomas. Sezary Syndrome, Skin Cancer, Small Cell Lung
Cancer, Small Intestine Cancer, Soft Tissue Sarcoma, Squamous Neck
Cancer, Stomach Cancer, Supratentorial Primitive Neuroectodermal
and Pineal Tumors, T-Cell Lymphoma, Testicular Cancer, Thymoma,
Thyroid Cancer, Transitional Cell Cancer of the Renal Pelvis and
Ureter, Transitional Renal Pelvis and Ureter Cancer, Trophoblastic
Tumors, Ureter and Renal Pelvis Cell Cancer, Urethral Cancer,
Uterine Cancer, Uterine Sarcoma, Vaginal Cancer, Visual Pathway and
Hypothalamic Glioma, Vulvar Cancer, Waldenstrom's
Macroglobulinemia, Wilms' Tumor, and any other hyperproliferative
disease, besides neoplasia, located in an organ system listed
above.
[0214] The methods and compositions described and claimed herein
may be used to treat malignant or premalignant conditions and to
prevent progression to a neoplastic or malignant state, including
but not limited to those disorders described above. Such uses are
indicated in conditions known or suspected of preceding progression
to neoplasia or cancer, in particular, where non-neoplastic cell
growth consisting of hyperplasia, metaplasia, or most particularly,
dysplasia has occurred (for review of such abnormal growth
conditions, see Robbins and Angell, Basic Pathology, 2d Ed., W. B.
Saunders Co., Philadelphia, pp. 68-79 (1976)).
[0215] Dysplasia is frequently a forerunner of cancer, and is found
mainly in the epithelia. It is the most disorderly form of
non-neoplastic cell growth, involving a loss in individual cell
uniformity and in the architectural orientation of cells. Dysplasia
characteristically occurs where there exists chronic irritation or
inflammation. Dysplastic disorders which can be treated include,
but are not limited to, anhidrotic ectodermal dysplasia,
anterofacial dysplasia, asphyxiating thoracic dysplasia,
atriodigital dysplasia, bronchopulmonary dysplasia, cerebral
dysplasia, cervical dysplasia, chondroectodermal dysplasia,
cleidocranial dysplasia, congenital ectodermal dysplasia,
craniodiaphysial dysplasia, craniocarpotarsal dysplasia,
craniometaphysial dysplasia, dentin dysplasia, diaphysial
dysplasia, ectodermal dysplasia, enamel dysplasia,
encephalo-ophthalmic dysplasia, dysplasia epiphysialis hemimelia,
dysplasia epiphysialis multiplex, dysplasia epiphysialis punctata,
epithelial dysplasia, faciodigitogenital dysplasia, familial
fibrous dysplasia of jaws, familial white folded dysplasia,
fibromuscular dysplasia, fibrous dysplasia of bone, florid osseous
dysplasia, hereditary renal-retinal dysplasia, hidrotic ectodermal
dysplasia, hypohidrotic ectodermal dysplasia, lymphopenic thymic
dysplasia, mammary dysplasia, mandibulofacial dysplasia,
metaphysial dysplasia, Mondini dysplasia, monostotic fibrous
dysplasia, mucoepithelial dysplasia, multiple epiphysial dysplasia,
oculoauriculovertebral dysplasia, oculodentodigital dysplasia,
oculovertebral dysplasia, odontogenic dysplasia,
opthalmomandibulomelic dysplasia, periapical cemental dysplasia,
polyostotic fibrous dysplasia, pseudoachondroplastic
spondyloepiphysial dysplasia, retinal dysplasia, septo-optic
dysplasia, spondyloepiphysial dysplasia, and ventriculoradial
dysplasia.
[0216] Additional pre-neoplastic disorders which can be treated
include, but are not limited to, benign dysproliferative disorders
(e.g., benign tumors, fibrocystic conditions, tissue hypertrophy,
intestinal polyps or adenomas, and esophageal dysplasia),
leukoplakia, keratoses, Bowen's disease, Farmer's Skin, solar
cheilitis, and solar keratosis.
[0217] In preferred embodiments, the method of the invention is
used to inhibit growth, progression, and/or metastasis of cancers,
in particular those listed above.
[0218] Additional hyperproliferative diseases, disorders, and/or
conditions include, but are not limited to, progression, and/or
metastases of malignancies and related disorders such as leukemia
(including acute leukemias (e.g., acute lymphocytic leukemia, acute
myelocytic leukemia (including myeloblastic, promyelocytic,
myelomonocytic, monocytic, and erythroleukemia)) and chronic
leukemias (e.g., chronic myelocytic (granulocytic) leukemia and
chronic lymphocytic leukemia)), polycythemia vera, lymphomas (e.g.,
Hodgkin's disease and non-Hodgkin's disease), multiple myeloma,
Waldenstrom's macroglobulinemia, heavy chain disease, and solid
tumors including, but not limited to, sarcomas and carcinomas such
as fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma,
osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma,
lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma,
mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma,
colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer,
prostate cancer, squamous cell carcinoma, basal cell carcinoma,
adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma,
papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma,
medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma,
hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal
carcinoma, Wilm's tumor, cervical cancer, testicular tumor, lung
carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial
carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma,
ependymoma, pinealoma, emangioblastoma, acoustic neuroma,
oligodendroglioma, meningioma, melanoma, neuroblastoma, and
retinoblastoma.
[0219] Therapy of Autoimmune Disease
[0220] The subject anti-CD22 antibodies, combinations or complexes
thereof can be used to treat immune dysregulation disease and
related autoimmune diseases. Immune diseases may include acute
immune thrombocytopenia, Addison's disease, adult respiratory
distress syndrome (ARDS), agranulocytosis, allergic conditions,
allergic encephalomyelitis, allergic neuritis, amyotrophic lateral
sclerosis (ALS), ankylosing spondylitis, antigen-antibody complex
mediated diseases, anti-glomerular basement membrane disease,
anti-phospholipid antibody syndrome, aplastic anemia, arthritis,
asthma, atherosclerosis, autoimmune disease of the testis and
ovary, autoimmune endocrine diseases, autoimmune myocarditis,
autoimmune neutropenia, autoimmune polyendocrinopathies, autoimmune
polyglandular syndromes (or polyglandular endocrinopathy
syndromes), autoimmune thrombocytopenia, Bechet disease, Berger's
disease (IgA nephropathy), bronchiolitis obliterans
(non-transplant), bullous pemphigoid, pemphigus vulgaris,
Castleman's syndrome, Celiac sprue (gluten enteropathy), central
nervous system (CNS) inflammatory disorders, chronic active
hepatitis, chronic immune thrombocytopenia dermatomyositis,
colitis, conditions involving infiltration of T cells and chronic
inflammatory responses, coronary artery disease, Crohn's disease,
cryoglobulinemia, dermatitis, dermatomyositis, diabetes mellitus,
diseases involving leukocyte diapedesis, eczema, encephalitis,
erythema multiforme, erythema nodosum, Factor VIII deficiency,
fibrosing alveolitis, giant cell arteritis, glomerulonephritis,
Goodpasture's syndrome, graft versus host disease (GVHD),
granulomatosis, Grave's disease, Guillain-Barre Syndrome.
Hashimoto's thyroiditis, hemophilia A, Henoch-Schonlein purpura,
idiopathic hypothyroidism, immune thrombocytopenia (ITP), IgA
nephropathy, IgA nephropathy, IgM mediated neuropathy, immune
complex nephritis, immune hemolytic anemia including autoimmune
hemolytic anemia (AIHA), immune responses associated with acute and
delayed hypersensitivity mediated by cytokines and T-lymphocytes,
immune-mediated thrombocytopenias, juvenile onset diabetes,
juvenile rheumatoid arthritis, Lambert-Eaton Myasthenic Syndrome,
large vessel vasculitis, leukocyte adhesion deficiency, leukopenia,
lupus nephritis, lymphoid interstitial pneumonitis (HIV), medium
vessel vasculitis, membranous nephropathy, meningitis, multiple
organ injury syndrome, multiple sclerosis, myasthenia gravis,
osteoarthritis, pancytopenia, pemphigoid bullous, pemphigus
vulgaris, pernicious anemia, polyarteritis nodosa, polychondritis,
polyglandular syndromes, polymyalgia, polymyositis,
post-streptococcal nephritis, primary biliary cirrhosis, primary
hypothyroidism, psoriasis, psoriatic arthritis, pure red cell
aplasia (PRCA), rapidly progressive glomerulonephritis, Reiter's
disease, respiratory distress syndrome, responses associated with
inflammatory bowel disease, Reynaud's syndrome, rheumatic fever,
rheumatoid arthritis, sarcoidosis, scleroderma, Sjogren's syndrome,
solid organ transplant rejection, Stevens-Johnson syndrome,
stiff-man syndrome, subacute thyroiditis, Sydenham's chorea,
systemic lupus erythematosus (SLE), systemic scleroderma and
sclerosis, tabes dorsalis, Takayasu's arteritis, thromboangitis
obliterans, thrombotic thrombocytopenic purpura (TTP),
thyrotoxicosis, toxic epidermal necrolysis, tuberculosis, Type I
diabetes, ulcerative colitis, uveitis, vasculitis (including ANCA)
and Wegener's granulomatosis.
[0221] Type-1 and Type-2 diabetes may be treated using known
antibodies against B-cell antigens, such as CD22 (epratuzumab),
CD74 (milatuzumab), CD19 (hA19), CD20 (veltuzumab) or HLA-DR
(hL243) (see, e.g., Winer et al., 2011, Nature Med 17:610-18).
Anti-CD3 antibodies also have been proposed for therapy of type 1
diabetes (Cernea et al., 2010, Diabetes Metab Rev 26:602-05).
[0222] Kits
[0223] Various embodiments may concern kits containing anti-CD22
antibodies, antibody combinations and/or antibody constructs and/or
other components. Such components may include a targetable
construct. In alternative embodiments it is contemplated that a
targetable construct may be attached to one or more different
therapeutic and/or diagnostic agents.
[0224] If the composition containing components for administration
is not formulated for delivery via the alimentary canal, such as by
oral delivery, a device capable of delivering the kit components
through some other mute may be included. One type of device, for
applications such as parenteral delivery, is a syringe that is used
to inject the composition into the body of a subject. Inhalation
devices may also be used for certain applications.
[0225] The kit components may be packaged together or separated
into two or more containers. In some embodiments, the containers
may be vials that contain sterile, lyophilized formulations of a
composition that are suitable for reconstitution. A kit may also
contain one or more buffers suitable for reconstitution and/or
dilution of other reagents. Other containers that may be used
include, but are not limited to, a pouch, tray, box, tube, or the
like. Kit components may be packaged and maintained sterilely
within the containers. Another component that can be included is
instructions to a person using a kit for its use.
EXAMPLES
[0226] Various embodiments of the present invention are illustrated
by the following examples, without limiting the scope thereof.
[0227] General Procedures
[0228] Abbreviations used below are: DCC, dicyclohexylcarbodiimide;
NHS, N-hydroxysuccinimide, DMAP, 4-dimethylaminopyridine; EEDQ,
2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline; MMT,
monomethoxytrityl; PABOH, p-aminobenzyl alcohol; PEG, polyethylene
glycol; SMCC, succinimidyl
4-(N-maleimidomethyl)cyclohexane-1-carboxylate; TBAF,
tetrabutylammonium fluoride; TBDMS, tert-butyldimethylsilyl
chloride.
[0229] Chloroformates of hydroxy compounds in the following
examples were prepared using triphosgene and DMAP according to the
procedure described in Moon et al. (J. Medicinal Chem.
51:6916-6926, 2008). Extractive work-up refers to extraction with
chloroform, dichloromethane or ethyl acetate, and washing
optionally with saturated bicarbonate, water, and with saturated
sodium chloride. Flash chromatography was done using 230-400 mesh
silica gel and a methanol-dichloromethane gradient, using up to 15%
v/v methanol-dichloromethane, unless otherwise stated. Reverse
phase HPLC was performed by Method A using a 7.8.times.300 mm C18
HPLC column, fitted with a precolumn filter, and using a solvent
gradient of 100% solvent A to 100% solvent B in 10 minutes at a
flow rate of 3 mL per minute and maintaining at 100% solvent B at a
flow rate of 4.5 mL per minute for 5 or 10 minutes; or by Method B
using a 4.6.times.30 mm C18, 2.5 .mu.m, column, fitted with a
precolumn filter, using the solvent gradient of 100% solvent A to
100% of solvent B at a flow rate of 1.5 mL per minutes for 4 min
and 100% of solvent B at a flow rate of 2 mL per minutes for 1
minutes. Solvent A was 0.3% aqueous ammonium acetate, pH 4.46 while
solvent B was 9:1 acetonitrile-aqueous ammonium acetate (0.3%), pH
4.46. HPLC was monitored by a dual in-line absorbance detector set
at 360 nm and 254 nm.
Example 1: Preparation of CL6-SN-38
[0230] An exemplary synthetic protocol for CL6-SN-38 is presented
in Scheme 1. Commercially available
O-(2-azidoethyl)-O'--(N-diglycolyl-2-aminoethyl)heptaethyleneglycol
(`PEG-N.sub.3`; 227 mg) was activated with DCC (100 mg), NHS (56
mg), and a catalytic amount of DMAP in 10 mL of dichloromethane for
10 min. To this mixture was added L-valinol (46.3 mg), and the
reaction mixture was stirred for 1 h at ambient temperature.
Filtration, followed by solvent removal and flash chromatography
yielded 214 mg of clear oily material. This intermediate (160 mg)
was reacted with 10-O-BOC-SN-38-20-O-chloroformate, the latter
generated from 10-O-BOC-SN-38 (123 mg) using triphosgene and DMAP.
The coupling reaction was done in 4 mL of dichloromethane for 10
min, and the reaction mixture was purified by flash chromatography
to obtain 130 mg (45% yield) of product as foamy material. HPLC:
t.sub.R 11.80 min; electrospray mass spectrum: M+Na: m/z 1181.
[0231] A maleimide-containing acetylenic reagent,
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide,
required for click cycloaddition, was prepared by reacting 0.107 g
of SMCC and 0.021 mL of propargylamine (0.018 g; 1.01 equiv.) in
dichloromethane using 1.1 equiv. of diisopropylethylamine. After 1
h, the solvent was removed and the product was purified by flash
chromatography to obtain 83 mg of the product (colorless powder).
Electrospray mass spectrum showed peaks at m/e 275 (M+H) and a base
peak at m/e 192 in the positive ion mode, consistent with the
structure calculated for C.sub.15H.sub.18N.sub.2O.sub.3: 275.1390
(M+H). found: 275.1394 (exact mass).
[0232] The azido intermediate (126 mg) described above was
dissolved in DMSO (1.5 mL) and water (0.4 mL), and reacted with 60
mg of 4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
and 15 mg of cuprous bromide and stirred for 30 min at ambient
temperature. Flash chromatography, after work up of the reaction
mixture, furnished 116 mg (75% yield) of the cycloaddition product.
HPLC: t.sub.R 11.20 min; electrospray mass spectrum: M+H and M+Na
at m/z 1433 and 1456, respectively. Finally, deprotection with a
mixture of TFA (5 mL), dichloromethane (1 mL), anisole (0.1 mL) and
water (0.05 mL), followed by precipitation with ether and
subsequent flash chromatography yielded the product, CL6-SN-38, as
a gummy material. HPLC: t.sub.R 9.98 min; electrospray mass
spectrum: M+H and M-H (negative ion mode) at m/z 1333 and 1356,
respectively.
##STR00009## ##STR00010##
Example 2: Preparation of CL7-SN-38
[0233] The synthesis of CL7-SN-38 is schematically shown in Scheme
2. L-Valinol (40 mg) was reacted with commercially available
Fmoc-Lys(MMT)-OH (253 mg) and EEDQ (107 mg) in 10 mL of anhydrous
dichloromethane at ambient temperature, under argon, for 3 h.
Extractive work up followed by flash chromatography furnished the
product Fmoc-Lys(MMT)-valinol as a pale yellow liquid (200 mg;
.about.70% yield). HPLC: t.sub.R 14.38 min: electrospray mass
spectrum: M+H: m/z 727. This intermediate (200 mg) was deprotected
with diethylamine (10 mL), and the product (135 mg) was obtained in
.about.90% purity after flash chromatography. HPLC: t.sub.R 10.91
min; electrospray mass spectrum: M+Na at m/z 527. This product (135
mg) was coupled with the commercially available
O-(2-azidoethyl)-O'--(N-diglycolyl-2-aminoethyl)heptaethylenegl-
ycol (`PEG-N.sub.3`; 150 mg, 0.1.1 equiv.) in presence of EEDQ (72
mg, 1.1 equiv.) in 10 mL of dichloromethane, and stirred overnight
at ambient temperature. The crude material was purified by flash
chromatography to obtain 240 mg of the purified product as a light
yellow oil (.about.87% yield). HPLC: t.sub.R 11.55 min;
electrospray mass spectrum: M+H and M+Na at m/z 1041 and 1063,
respectively.
[0234] This intermediate (240 mg) was reacted with
10-O-TBDMS-SN-38-20-O-chloroformate, the latter generated from
10-O-TBDMS-SN-38 (122 mg) using triphosgene and DMAP. The coupling
reaction was done in 5 mL of dichloromethane for 10 min, and the
reaction mixture was purified by flash chromatography to obtain 327
mg of product as pale yellow foam. Electrospray mass spectrum: M+H
at m/z 1574. The entire product was reacted with 0.25 mmol of TBAF
in 10 mL of dichloromethane for 5 min, and the reaction mixture was
diluted to 100 mL and washed with brine. Crude product (250 mg) was
dissolved in DMSO (2 mL) and water (0.4 mL), and reacted with 114
mg of 4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(prepared as described in Example 1) and 30 mg of cuprous bromide
and stirred for 1 h at ambient temperature. Flash chromatography
furnished 150 mg of the penultimate intermediate. Finally,
deprotection of the MMT group with a mixture of TFA (0.5 mL) and
anisole (0.05 mL) in dichloromethane (5 mL) for 3 min, followed by
purification by flash chromatography yielded 69 mg of CL7-SN-38 as
a gummy material. HPLC: t.sub.R 9.60 min; electrospray mass
spectrum: M+H and M-H (negative ion mode) at m/z 1461 and 1459,
respectively.
##STR00011## ##STR00012##
Example 3: Preparation of CL6-SN-38-10-O--CO.sub.2Et
[0235] The CL6-SN-38 of Example 1 (55.4 mg) was dissolved in
dichloromethane (5 mL), and reacted with ethylchloroformate (13.1
mg; 11.5 .mu.L) and diisopropylethylamine (52.5 mg: 71 .mu.L), and
stirred for 20 min under argon. The reaction mixture was diluted
with 100 mL of dichloromethane, and washed with 100 mL each of 0.1
M HCl, half saturated sodium bicarbonate and brine, and dried.
Flash chromatography, after solvent removal, furnished 59 mg of the
title product. HPLC: t.sub.R 10.74 min; exact mass: calc. 1404.6457
(M+H) and 1426.6276 (M+Na). found: 1404.6464 (M+H) and 1426.6288
(M+Na).
Example 4: Preparation of CL7-SN-38-10-O--CO.sub.2Et
[0236] The precursor of CL7-SN-38 of Example 2 (80 mg) was
converted to the 10-O-chloroformate using the procedure and
purification as described in Example 3. Yield: 60 mg. HPLC: t.sub.R
12.32 min; electrospray mass spectrum: M+H and M-H (negative ion
mode) at m/z 1806 and 1804, respectively. Deprotection of this
material using dichloroacetic acid and anisole in dichloromethane
gave CL7-SN-38-10-O--CO.sub.2Et. HPLC: t.sub.R 10.37 min;
electrospray mass spectrum: M+H at m/z 1534.
Example 5: Preparations of CL6-SN-38-10-O--COR and
CL7-SN-38-10-O--COR
[0237] This Example shows that the 10-OH group of SN-38 is
protected as a carbonate or an ester, instead of as `BOC`, such
that the final product is ready for conjugation to antibodies
without need for deprotecting the 10-OH protecting group. This
group is readily deprotected under physiological pH conditions
after in vivo administration of the protein conjugate. In these
conjugates, `R` can be a substituted alkyl such as
(CH.sub.2).sub.n--N(CH.sub.3).sub.2 where n is 2-10, or a simple
alkyl such as (CH.sub.2)n-CH.sub.3 where n is 0-10, or it can be an
alkoxy moiety such as "CH.sub.3--(CH.sub.2)n-O--" where n is 0-10,
or a substituted alkoxy moiety such as such as
O--(CH.sub.2).sub.n--N(CH.sub.3).sub.2 where n is 2-10 and wherein
the terminal amino group is optionally in the form of a quaternary
salt for enhanced aqueous solubility, or
"R.sub.1O--(CH.sub.2--CH.sub.2--O).sub.n--CH.sub.2--CH.sub.2--O--"
where R.sub.1 is ethyl or methyl and n is an integer with values of
0-10. In the simplest version of the latter category,
R="--O--(CH.sub.2).sub.2--OCH.sub.3". These 10-hydroxy derivatives
are readily prepared by treatment with the chloroformate of the
chosen reagent, if the final derivative is to be a carbonate.
Typically, the 10-hydroxy-containing camptothecin such as SN-38 is
treated with a molar equivalent of the chloroformate in
dimethylformamide using triethylamine as the base. Under these
conditions, the 20-OH position is unaffected. For forming
10-O-esters, the acid chloride of the chosen reagent is used. Such
derivatizations are conveniently accomplished using advanced
intermediates as illustrated for simple ethyl carbonates of
Examples 3 and 4.
Example 6: Preparation of CL6-Paclitaxel
[0238] Valinol is coupled to `PEG-N3` of Scheme 1 according to the
procedure described in Example 1. The product is reacted with 0.4
molar equivalent of triphosgene, 3.1 molar equivalent of DMAP, in
dichloromethane. After 5 minutes, the chloroformate so formed is
reacted with an equimolar amount of paclitaxel for 15 minutes at
ambient temperature. The reactive 2'-hydroxyl group of paclitaxel
(the side chain secondary hydroxyl group) reacts with the
chloroformate of the cross-linker. The product is isolated by flash
chromatography. This intermediate (0.1 mmol) is dissolved in DMSO
(1.5 mL) and water (0.4 mL), and reacted with 60 mg of
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(prepared as described in Example 1) and 15 mg of cuprous bromide
and stirred for 30 min at ambient temperature. Flash
chromatography, after work up of the reaction mixture, furnishes
the bifunctional paclitaxel, namely CL6-paclitaxel.
Example 7: Preparation of CL7-Paclitaxel
[0239] L-Valinol (40 mg) is reacted with commercially available
Fmoc-Lys(MMT)-OH, and the product is then reacted with
O-(2-azidoethyl)-O'--(N-diglycolyl-2-aminoethyl)heptaethyleneglycol
(`PEG-N.sub.3`), as described in Example 2. The chloroformate of
this derivative is formed by the method of Example-6, and reacted
with an equimolar amount of paclitaxel. The reactive 2'-hydroxyl
group of paclitaxel (the side chain secondary hydroxyl group)
reacts with the chloroformate of the cross-linker. Click
cycloaddition, using
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(prepared as described in Example 1) is then performed in a manner
similar to that described in Example 6, and the product is finally
treated with dichloroacetic acid and anisole to effect removal of
the `MMT` group under mild conditions. This process furnishes
CL7-paclitaxel.
Example 8: Preparation of CL6-[Morpholino Doxorubicin]
[0240] Valinol is coupled to `PEG-N3` of Scheme 1 according to the
procedure described in Example 1. The product is reacted with 0.4
molar equivalent of triphosgene, 3.1 molar equivalent of DMAP, in
dichloromethane. After 5 minutes, the chloroformate so formed is
reacted with an equimolar amount of morpholino doxorubicin for 15
minutes at ambient temperature. The primary hydroxyl group of
morpholino doxorubicin reacts with the chloroformate of the
cross-linker. The product is isolated by flash chromatography. This
intermediate (0.1 mmol) is dissolved in DMSO (1.5 mL) and water
(0.4 mL), and reacted with 60 mg of
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(prepared as described in Example 1) and 15 mg of cuprous bromide
and stirred for 30 min at ambient temperature. Flash
chromatography, after work up of the reaction mixture, furnishes
the bifunctional paclitaxel, namely CL6-[morpholino
doxorubicin].
Example 9: Preparation of CL7-[Morpholino Doxorubicin]
[0241] L-Valinol (40 mg) is reacted with commercially available
Fmoc-Lys(MMT)-OH, and the product is then reacted with
O-(2-azidoethyl)-O'--(N-diglycolyl-2-aminoethyl)heptaethyleneglycol
(`PEG-N.sub.3`), as described in Example 2. The chloroformate of
this derivative is formed by the method of Example-6, and reacted
with an equimolar amount of morpholino doxorubicin. The primary
hydroxyl group of morpholino doxorubicin reacts with the
chloroformate of the cross-linker. Click cycloaddition, using
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(prepared as described in Example 1) is then performed in a manner
similar to that described in Example 6, and the product is finally
treated with dichloroacetic acid and anisole to effect removal of
the `MMT` group under mild conditions. This process furnishes
CL7-[morpholino doxorubicin].
Example 10: Preparation of CL2A-SN-38
[0242] An exemplary method for preparing CL2A-SN-38 is shown in
Scheme 3. EEDQ (0.382 g) was added to a mixture of commercially
available Fmoc-Lys(MMT)-OH (0.943 g), p-aminobenzyl alcohol (0.190
g) in methylene chloride (10 mL) at room temperature and stirred
for 4 h. Extractive work up followed by flash chromatograph yielded
1.051 g of material as white foam. All HPLC analyses were performed
by Method B as stated in `General Procedures`. HPLC retention time
was 3.53 min. Electrospray mass spectrum showed peaks at m/e 745.8
(M+H) and m/e 780.3 (M+Cl.sup.-), consistent with structure. This
intermediate (0.93 g) was dissolved in diethylamine (10 mL) and
stirred for 2 h. After solvent removal, the residue was washed in
hexane to obtain 0.6 g of the intermediate ((2) in Scheme 3) as a
colorless precipitate (91.6% pure by HPLC). HPLC retention time was
2.06 min. Electrospray mass spectrum showed peaks at m/e 523.8
(M+H), m/e 546.2 (M+Na) and m/e 522.5 (M-H). This crude
intermediate (0.565 g) was coupled with commercially available
O-(2-azidoethyl)-O'--(N-diglycolyl-2-aminoethyl)heptaethyleneglycol
(`PEG-N3`, 0.627 g) using EEDQ in methylene chloride (10 mL).
Solvent removal and flash chromatography yielded 0.99 g of the
product ((3) in Scheme 3; light yellow oil; 87% yield). HPLC
retention time was 2.45 min. Electrospray mass spectrum showed
peaks at m/e 1061.3 (M+H), m/e 1082.7 (M+Na) and m/e 1058.8 (M-H),
consistent with structure. This intermediate (0.92 g) was reacted
with 10-O-TBDMS-SN-38-20-O-chloroformate ((5) in Scheme 3) in
methylene chloride (10 mL) for 10 min under argon. The mixture was
purified by flash chromatography to obtain 0.944 g as a light
yellow oil ((6) in Scheme 3; yield=68%). HPLC retention time was
4.18 min. To this intermediate (0.94 g) in methylene chloride (10
mL) was added a mixture of TBAF (1M in THF, 0.885 mL) and acetic
acid (0.085 mL) in methylene chloride (3 mL), then stirred for 10
min. The mixture was diluted with methylene chloride (100 mL) and
washed with 0.25 M sodium citrate and brine. The solvent removal
yielded 0.835 g of yellow oily product. HPLC retention time was
2.80 min (99% purity). Electrospray mass spectrum showed peaks at
m/c 1478 (M+H), m/e 1500.6 (M+Na), m/e 1476.5 (M-H), m/e 1590.5
(M+TFA), consistent with structure.
[0243] This azido-derivatized SN-38 intermediate (0.803 g) was
reacted with
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(0.233 g) in methylene chloride (10 mL) in the presence of CuBr
(0.0083 g), DIEA (0.01 mL) and triphenylphosphine (0.015 g), for 18
h. Extractive work up, including washing with 0.1M EDTA (10 mL),
and flash chromatography yielded 0.891 g as yellow foam
(yield=93%). HPLC retention time was 2.60 min. The electrospray
mass spectrum showed peaks at m/c 1753.3 (M+H), m/e 1751.6 (M-H),
1864.5 (M+TFA), consistent with structure. Finally, deprotection of
the penultimate intermediate (0.22 g) with a mixture of
dichloroacetic acid (0.3 mL) and anisole (0.03 mL) in methylene
chloride (3 mL), followed by precipitation with ether yielded 0.18
g (97% yield) of CL2A-SN-38; (7) in Scheme 3) as a light yellow
powder. HPLC retention time was 1.88 min. Electrospray mass
spectrum showed peaks at m/c 1480.7 (M+H), 1478.5 (M-H), consistent
with structure.
##STR00013##
Example 11: Preparation of CL2E-SN-38
[0244] An exemplary method for preparing CL2E-SN-38 is shown in
Scheme 4. N,N'-dimethylethylenediamine (3 mL) in methylene chloride
(50 mL) was reacted with monomethoxytrityl chloride (1.7 g). After
1 h of stirring, the solvent was removed under reduced pressure,
and the crude product was recovered by extractive work up (yellow
oil; 2.13 g). All HPLC analyses were performed by Method B as
stated in `General Procedures`. HPLC retention time was 2.28 min.
This intermediate ((1) in Scheme 4; 0.93 g) was added in situ to
activated SN-38, and the latter ((2) in Scheme 4) was prepared by
reacting SN-38 (0.3 g) with p-nitrophenylchloroformate (0.185 g)
and DIEA (0.293 mL) in DMF for 1 h. After removing solvent, the
residue was purified on deactivated silica gel to obtain 0.442 g as
white solid. This intermediate (0.442 g) was deprotected with a
mixture of trifluoroacetic acid (1 mL) and anisole (0.1 mL) in
methylene chloride (5 mL), followed by precipitation with ether to
obtain 0.197 g of the product ((3) in Scheme 4) as white solid.
[0245] This intermediate (0.197 g) was coupled with activated
azide-containing-dipeptide incorporated-PEG-linker ((5) in Scheme
4), which activation was done by reacting PEG-linker ((4) in Scheme
4; 0.203 g) with bis(4-nitrophenyl) carbonate (0.153 g) and DIEA
(0.044 mL) in methylene chloride (8 mL). Flash chromatography
yielded 0.2 g of azide-derivatized SN-38 intermediate product ((6)
in Scheme 4) as a glassy solid. HPLC ret. time: 2.8 min.
Electrospray mass spectrum showed peaks at m/e 1740.5 (M+H), m/e
1762.9 (M+Na), m/e 1774.9 (M+Cl.sup.-), consistent with structure.
This intermediate ((6) in Scheme 4; 0.2 g) was subjected to click
cycloaddition with
4-(N-maleimidomethyl)-N-(2-propynyl)cyclohexane-1-carboxamide
(0.067 g) in methylene chloride in the presence of CuBr (0.007 g),
DIEA (0.008 mL) and triphenylphosphine (0.012 g) for 18 h. Work up
of the reaction mixture, which included treatment with 0.1M EDTA,
followed by flash chromatography yielded 0.08 g of the penultimate
intermediate as a light yellow foam. HPLC: t.sub.R=2.63 min.
Electrospray mass spectrum showed peaks at m/e 2035.9 (M+Na.sup.+),
m/e 2047.9 (M+Cl.sup.-), consistent with structure. Finally,
deprotection of this intermediate (0.08 g) with a mixture of
trifluoroacetic acid (0.2 mL), anisole (0.12 mL) and water (0.06
mL) in methylene chloride (2 mL), followed by precipitation with
ether yielded 0.051 g of product, CL17-SN-38 (also referred to as
CL2E-SN-38), as a light yellow powder (yield=69%). HPLC ret. time:
1.95 min., .about.99% purity. Electrospray mass spectrum showed
peaks at m/e 1741.1 (M+H), 1775.5 (M+Cl.sup.-), consistent with
structure.
##STR00014## ##STR00015##
Example 12: Conjugation of Bifunctional SN-38 Products to Mildly
Reduced Antibodies
[0246] The anti-CEACAM5 humanized MA, hMN-14, the anti-CD22
humanized MAb, hLL2, the anti-CD20 humanized MAb, hA20, the
anti-EGP-1 humanized MAb, hRS7, and anti-mucin humanized MAb,
hPAM4, were used in these studies. Each antibody was reduced with
dithiothreitol (DTT), used in a 50-to-70-fold molar excess, in 40
mM PBS, pH 7.4, containing 5.4 mM EDTA, in a 37.degree. C. bath for
45 min. The reduced product was purified by size-exclusion
chromatography and/or diafiltration, and was buffer-exchanged into
a suitable buffer at pH 6.5. The thiol content was determined by
Ellman's assay, and was in the 6.5-to-8.5 SH/IgG range.
Alternatively, the antibodies were reduced with Tris
(2-carboxyethyl) phosphine (TCEP) in phosphate buffer at a pH in
the range of 5 to 7, followed by in situ conjugation. The reduced
MAb was reacted with .about.10-to-15-fold molar excess of CL6-SN-38
of Example 1, or CL7-SN-38 of Example 2, or
CL6-SN-38-10-O--CO.sub.2Et of Example 3, or
CL7-SN-38-10-O--CO.sub.2Et of Example 4, or CL2A-SN-38 of Example
10, or CL2E-SN-38 of Example 11 using DMSO at 7-15% v/v as a
co-solvent, and incubating for 20 min at ambient temperature. The
conjugate was purified by centrifuged SEC, passage through a
hydrophobic column, and finally by ultrafiltration-diafiltration.
The product was assayed for SN-38 by absorbance at 366 nm and
correlating with standard values, while the protein concentration
was deduced from absorbance at 280 nm, corrected for spillover of
SN-38 absorbance at this wavelength. The SN-38/MAb substitution
ratios were determined. The purified conjugates were stored as
lyophilized formulations in glass vials, capped under vacuum and
stored in a -20.degree. C. freezer. SN-38 molar substitution ratios
(MSR) obtained for some of these conjugates, which were typically
in the 5 to 7 range, are shown in Table 7.
TABLE-US-00021 TABLE 7 SN-38/MAb Molar substitution ratios (MSR) in
some conjugates MAb Conjugate MSR hMN-14 hMN-14-[CL2A-SN-38], using
drug-linker of 6.1 Example 10 hMN-14-[CL6-SN-38], using drug-linker
of Example 1 6.8 hMN-14-[CL7-SN-38], using drug-linker of Example 2
5.9 hMN-14-[CL7-SN-38-10-O--CO.sub.2Et], using drug- 5.8 linker of
Example 4 hMN-14-[CL2E-SN-38], using drug-linker of 5.9 Example 11
hRS7 hRS7-CL2A-SN-38 using drug-linker of Example 10 5.8
hRS7-CL7-SN-38 using drug-linker of Example 2 5.9 hRS7-CL7-SN-38
(Et) using drug-linker of Example 4 6.1 hA20 hA20-CL2A-SN-38 using
drug-linker of Example 10 5.8 hLL2 hLL2-CL2A-SN-38 using
drug-linker of Example 10 5.7 hPAM4 hPAM4-CL2A-SN-38 using
drug-linker of Example 10 5.9
Example 13. Lyophilized Preparations of SN-38 Immunoconjugates
[0247] In a preferred embodiment of the immunoconjugates described
in Example 12 above, the purified conjugates are contained in the
pH range of 5.5 to 7.5 in any of the following Good's biological
buffers derived from: 2-(N-morpholino)ethanesulfonic acid (MES),
N-(2-acetamido)-2-iminodiacetic acid (ADA),
1,4-piperazinediethanesulfonic acid (PIPES),
N-(2-acetamido)-2-aminoethanesulfonic acid (ACES),
N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES),
N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), and
N-(2-hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid) or HEPES.
The most preferred buffer is 25 mM MES, pH 6.5. In an exemplary
preparation of a lyophilized conjugate, a solution (69 mL; 16.78
mg/mL protein concentration) of the purified CL2A-SN-38 conjugate
of the anti-CD22 antibody, hLL2, namely hLL2-CL2A-SN-38, in 25 mM
MES, pH 6.5 buffer, was diluted with 34.1 mL of the same buffer,
and mixed with 11.6 mL of 250 mM trehalose and 1.16 mL of 1%
polysorbate 80. The formulated solution was aliquoted in 50-mg
aliquots in various vials, and lyophilized. The vials containing
lyophilized immunoconjugate were sealed under vacuum, and stored at
2-8.degree. C. in a refrigerator. The lyophilized immunoconjugate
was stable under these conditions.
Example 14. In Vivo Therapeutic Efficacies in Preclinical Models of
Human Pancreatic or Colon Carcinoma
[0248] Immune-compromised athymic nude mice (female), bearing
subcutaneous human pancreatic or colon tumor xenografts were
treated with either specific CL2A-SN-38 conjugate or control
conjugate or were left untreated. The therapeutic efficacies of the
specific conjugates were observed. FIG. 1 shows a Capan 1
pancreatic tumor model, wherein specific CL2A-SN-38 conjugates of
hRS7 (anti-EGP-1), hPAM4 (anti-mucin), and hMN-14 (anti-CEACAM5)
antibodies showed better efficacies than control hA20-CL2A-SN-38
conjugate (anti-CD20) and untreated control. Similarly in a BXPC3
model of human pancreatic cancer, the specific hRS7-CL2A-SN-38
showed better therapeutic efficacy than control treatments (FIG.
2). Likewise, in an aggressive LS174T model of human colon
carcinoma, treatment with specific hMN-14-CL2A-SN-38 was more
efficacious than control treatment (FIG. 3).
Example 15. Humanized Anti-CD22 MAb (Epratuzumab) Conjugated with
SN-38, Alone or in Combination with Anti-CD20 MAb (Veltuzumab),
Shows Potent Efficacy for Therapy of Hematologic Tumors
[0249] Monoclonal antibody therapy has had a significant impact on
the management of B-cell malignancies, but is most often used in
combination with chemotherapy. We developed an antibody-drug
conjugate (ADC) that combines SN-38, the active component of
irinotecan, a topoisomerase I inhibitor, with an internalizing,
humanized anti-CD22 IgG (epratuzumab) and determined its activity
alone and in combination with an anti-CD20 antibody
(veltuzumab).
[0250] The CD22 antigen is expressed in most NHL and ALL specimens.
Epratuzumab (humanized anti-CD22 MAb) is an internalizing antibody
that has been shown to be safe and therapeutically effective as a
naked antibody alone and in combination with rituximab. Epratuzumab
is currently being studied in pediatric ALL, as well as a
radioconjugate in NHL. (See, e.g., Leonard et al., 2008, Cancer
113:2714-23; Raetz et al., 2008, J Clin Oncol 26:3756-62;
Morschhauser et al., 2010, J Clin Oncol 28:3709-16). Therapeutic
use of epratuzumab is not limited to B cell malignancies, but has
also been proposed for autoimmune diseases such as systemic lupus
erythematosus (SLE) (Dorner et al., 2006, Arthritis Res Ther 8:R74;
Daridon et al., 2010, Arthritis Res Ther 12:R204).
[0251] Veltuzumab (humanized anti-CD20) has shown
anti-proliferative, apoptotic and ADCC effects in vitro similar to
rituximab, but with significantly slower off-rates and increased
CDC in several human lymphoma cell lines (see, e.g., U.S. Pat. No.
7,919,273, incorporated herein by reference from Col. 34, line 15
to Col. 72, line 2). Very low doses of veltuzumab, given either
intravenously or subcutaneously, depleted B cells in normal
cynomolgus monkeys and controlled tumor growth in mice bearing
human lymphomas. Veltuzumab has been clinically studied in over 150
patients with lymphomas and autoimmune diseases. In non-Hodgkin
lymphoma (NHL), infusions of 80-750 mg/m.sup.2 were well tolerated
when given once-weekly for four doses, with the only toxicity being
transient mild-moderate infusion reactions. Objective tumor
responses, including durable complete responses, occurred at all
dose levels. Subcutaneous injections of low doses (80-320 mg) have
also proved to be safe and pharmacologically active, producing
objective responses, including durable complete responses, at rates
comparable to those reported with rituximab, in patients with NHL
and immune thrombocytopenia. (See, e.g., Goldenberg et al., 2010. J
Clin Oncol 28:3709-16; Goldenberg et al., 2010, Leuk Lymphoma
51:747-55; Negrea et al., 2011, Haematologica 96:567-73; Goldenberg
et al., 2009, Blood 113:1062-70; Morchhauser et al., 2009, J Clin
Oncol 27:3346-53; Sharkey et al., 2009, J Nucl Med 50:444-53.)
[0252] Epratuzumab was conjugated with SN-38 (E-SN-38) at a mole
ratio of .about.6:1, using a CL2A linker as described in Examples
10 and 12 above. Conjugation had no effect on the affinity of the
antibody for the target antigen (data not shown). The conjugate was
designed to be released slowly in the presence of serum (50%
released over .about.1.5 days), allowing liberation of the drug
when internalized, but also being released locally after binding to
the tumor. In vitro and in vivo studies were performed to assess
the activity of the conjugate against several subcutaneously- or
intravenously-inoculated B-cell lymphoma cell lines. In vivo
studies also examined combination therapy using E-SN-38 and the
anti-CD20 antibody veltuzumab (V).
[0253] In vitro studies in 4 B-cell lymphoma cells lines (Daudi,
Raji, Ramos, WSU-FSCCL) and 4 acute lymphoblastic lymphoma cell
lines (697, REH, MN-60 and RS4; 11) expressing varying amounts of
CD22 showed an IC.sub.50 for E-SN-38 in the nanomolar range,
confirming potent activity. As shown in Table 8, the IC.sub.50 for
E-SN-38 did not strictly correlate with CD22 expression or with
sensitivity to non-targeted SN-38.
TABLE-US-00022 TABLE 8 Expression of CD20 and CD22 and in vitro
cytotoxicity of SN-38 and E-SN-38 CD20 Expression CD22 Expression
E-SN-38 % % SN-38 IC.sub.50 Cell Line FACS positive FACS positive
IC.sub.50 (nM) (nM) Raji 283.6 99.3 47.7 89.3 1.42 2.10 Ramos 27.2
91.6 7.1 2.2 0.40 2.92 Daudi 18.7 20.3 10.7 3.1 0.13 0.52 WSU- 8.8
7.8 6.2 0.8 0.50 0.68 FSCCL REH 92.0 55.1 52.9 99.7 0.47 1.22 697
12.0 22.0 42.2 100 2.23 2.67 RS4; 11 8.4 15.0 34.3 94.5 2.28 1.68
MN-60 N.D. N.D. 1.23 3.65
[0254] Nude or SCID mice were implanted SC with Ramos cells
(Burkitt's lymphoma) or IV with WSU-FSCCL (follicular lymphoma,
FIG. 4, FIG. 5) or 697 (ALL, FIG. 6) cell lines. All doses of
immunoconjugates or drugs were given intraperitoneally, twice
weekly for 4 weeks. Irinotecan (CPT-11) was administered at the
same mole equivalent as the antibody-conjugated SN-38. All dose
levels were well tolerated in mice, with toxicity only found at
doses of 2.times.30 mg (2.times.1500 mg/kg) For Ramos, the endpoint
was time to progression to 3.0 cm.sup.3 tumor size. For WSU-FSCCL
and 697, therapy was started 5 days after tumor cell injection. The
end of study was progression to hind-leg paralysis, 20% or greater
loss in body weight, or other signs of stress. Statistical analysis
was by log-rank test.
[0255] E-SN-38 was active in mice at a dose of 2.times..ltoreq.0.5
mg weekly for 4 weeks (50 mg/kg per week). Toxicology studies in
monkeys and rabbits of other IgG-SN-38 conjugates have found a
human equivalent of 40 mg/kg/week to be non-toxic, which is
approximately 25 mg SN-38 equivalents/m.sup.2. Thus, the
therapeutic window of emab-SN-38 is at least 10:1.
[0256] Nude mice bearing SC Ramos human lymphoma had significant
selective anti-tumor activity compared to a control, non-targeting,
IgG-SN-38 conjugate, at a dosing regimen of 75 to 250 .mu.g of the
conjugates given twice-weekly for 4 weeks (FIG. 7). Responses
improved in a dose-dependent manner for both the specific and
irrelevant immunoconjugates.
[0257] Significant anti-tumor activity was also found in several
other cell lines. When combined with veltuzumab, significant
improvement in therapeutic activity was observed (FIG. 4, FIG. 5).
For example, median survival in a WSU-FSCCL human follicular B-cell
lymphoma IV model with treatment initiated 5 days after
implantation was 41 d (0/10 surviving at 160d) and 91 d (2/10
surviving at 160 d) for untreated and veltuzumab-treated animals,
respectively; 63 d (0/10 surviving after 160 d) and >160 d (6/10
surviving after 160 d) for E-SN-38 and E-SN-38+V, respectively; and
63 d (0/10) and 91 d (2/10) for non-targeting IgG-SN-38 conjugate
alone and combined with V, respectively. The E-SN-38 conjugate
combined with V was significantly better than all other treatment
or control groups (P.ltoreq.0.05). We conclude that E-SN-38 ADC is
a potent therapeutic, even at non-toxic dose levels, and shows
significantly enhanced efficacy when combined with anti-CD20
immunotherapy, representing an important new ADC treatment regimen
for B cell diseases.
Example 16. Preparation of hLL1, hLL2, hA20 and hL243
Antibodies
[0258] The hLL1, hLL2, hA20 and hL243 antibodies were prepared as
previously described and as summarized below. The constant region
sequences of each of the hLL1, hLL2, hA20 and hL243 antibodies are
as shown below in SEQ ID NO:14 (heavy chain constant region amino
acid sequence); SEQ ID NO: 134 (heavy chain constant region DNA
sequence); SEQ ID NO: 135 (light chain constant region amino acid
sequence); and SEQ ID NO:136 (light chain constant region amino
acid sequence). Although the constant region sequences are derived
from the hLL2 antibody, they are identical in each of hLL1, hLL2,
hA20 and hL243. Therefore, each of the hLL1, hLL2, hA20 and hL243
antibodies is a G1m3 allotype antibody.
TABLE-US-00023 Heavy chain constant region amino acid sequence
(CH1-Hinge-CH2--CH3) (SEQ ID NO: 14)
ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGV
HTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVHKPSNTKVDKRVEPK
SCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSH
EDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKE
YKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCL
VKGFYPSDIAYEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQ
QGNVFSCSVMHEALHNHYTQKSLSLSPGK Heavy chain constant region DNA
sequence (SEQ ID NO: 134)
GCCTCCACCAAGGGCCCATCGGTCTTCCCCCTGGCACCCTCCTCCAAGAG
CACCTCTGGGGGCACAGCGGCCCTGGGCTGCCTGGTCAAGGACTACTTCC
CCGAACCGGTGACGGTGTCGTGGAACTCAGGCGCCCTGACCAGCGGCGTG
CACACCTTCCCGGCTGTCCTACAGTCCTCAGGACTCTACTCCCTCAGCAG
CGTGGTGACCGTGCCCTCCAGCAGCTTGGGCACCCAGACCTACATCTGCA
ACGTGAATCACAAGCCCAGCAACACCAAGGTGGACAAGAGAGTTGAGCCC
AAATCTTGTGACAAAACTCACACATGCCCACCGTGCCCAGCACCTGAACR
CCTGGGGGGACCGTCAGTCTTCCTCTTCCCCCCAAAACCCAAGGACACCC
TCATGATCTCCCGGACCCCTGAGGTCACATGCGTGGTGGTGGACGTGAGC
CACGAAGACCCTGAGGTCAAGTTCAACTGGTACGTGGACGGCGTGGAGGT
GCATAATGCCAAGACAAAGCCGCGGGAGGAGCAGTACAACAGCACGTACC
GGGTGGTCAGCGTCCTCACCGTCCTGCACCAGGACTGGCTGAATGGCAAG
GAGTACAAGTGCAAGGTCTCCAACAAAGCCCTCCCAGCCCCCATCGAGAA
AACCATCTCCAAAGCCAAAGGGCAGCCCCGAGAACCACAGGTGTACACCC
TGCCCCCATCCCGGGAGGAGATGACCAAGAACCAGGTCAGCCTGACCTGC
CTGGTCAAAGGCTTCTATCCCAGCGACATCGCCGTGGAGTGGGAGAGCAA
TGGGCAGCCGGAGAACAACTACAAGACCACGCCTCCCGTGCTGGACTCCG
ACGGCTCCTTCTTCCTCTATAGCAAGCTCACCGTGGACAAGAGCAGGTGG
CAGCAGGGGAACGTCTTCTCATGCTCCGTGATGCATGAGGCTCTGCACAA
CCACTACACGCAGAAGAGCCTCTCCCTGTCTCCGGGTAAA Light chain constant
region amino acid sequence (SEQ ID NO: 135)
TVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGN
SQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKS FNRGEC Light
chain constant region DNA sequence (SEQ ID NO: 136)
ACTGTGGCTGCACCATCTGTCTTCATCTTCCCGCCATCTGATGAGCAGTT
GAAATCTGGAACTGCCTCTGTTGTGTGCCTGCTGAATAACTTCTATCCCA
GAGAGGCCAAAGTACAGTGGAAGGTGGATAACGCCCTCCAATCGGGTAAC
TCCCAGGAGAGTGTCACAGAGCAGGACAGCAAGGACAGCACCTACAGCCT
CAGCAGCACCCTGACGCTGAGCAAAGCAGACTACGAGAAACACAAAGTCT
ACGCCTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGC
TTCAACAGGGGAGAGTGT
[0259] hLL1 Antibody
[0260] The hLL1 anti-CD74 antibody was prepared as described in
U.S. Pat. No. 7,772,373 (incorporated by reference from Col. 3,
line 54 to Col. 5, line 32 and Col. 34, line 15 to Col. 40, line
45, FIGS. 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B). The variable region
sequences of the light and heavy chains of the hLL1 antibody are as
described in U.S. Pat. No. 7,772,373 (e.g., FIG. 3 and FIG. 4).
[0261] A modified strategy as described by Leung et al. (1994,
Hybridoma 13:469-76) was used to construct the VK and VH genes for
hLL1 using a combination of long oligonucleotide synthesis and PCR.
For the construction of the hLL11 VH domain, two long
oligonucleotides, hLL1VHA (176 mer) and hLL1VHB (165-mer) (U.S.
Pat. No. 7,772,373) were synthesized on an automated DNA
synthesizer. The hLL1VHA sequence represented nt 20 to 195 of the
hLL1VH domain. The hLL1 VHB sequence represented the minus strand
of the hLL1 VH domain complementary to nt 173 to 337. The
3'-terminal sequences (22 nt residues) of hLL1VHA and B were
complementary to each other. Under PCR condition, the 3'-ends of
hLL1 VHA and B annealed to form a short double stranded DNA. Each
annealed end served as a primer for the transcription of single
stranded DNA, resulting in a double strand DNA composed of the nt
20 to 337 of hLL1 VH. This DNA was further amplified in the
presence of two short oligonucleotides, hLL1VHBACK and hLL1VHFOR
(U.S. Pat. No. 7,772,373) to form the full-length hLL1VH.
Double-stranded PCR-amplified product for hLL1 VH was gel-purified,
restriction-digested with PstI and BstEII and cloned into the
complementary PstI/BstEII sites of the heavy chain staging vector,
VHpBS2.
[0262] For constructing the full length DNA of the humanized VK
sequence, hLL1VKA (159-mer) and hLL1VKB (169-mer) (U.S. Pat. No.
7,772,373) were synthesized. The hLL1 VKA sequence represented nt
16 to 174 of the hLL1VK domain. The hLL11VKB sequence represented
the minus strand of the hLL1 VK domain complementary to nt 153 to
321. hLL1 VKA and B were amplified by two short oligonucleotides
hLL1VKBACK and hLL1 VKFOR (U.S. Pat. No. 7,772,373) to form
double-stranded DNA. Further amplification produced the full length
VK gene (U.S. Pat. No. 7,772,373). Gel-purified PCR products for
hLL1VK were restriction-digested with PvuII and BgIIII and cloned
into the complementary PvuI/BcII sites of the light chain staging
vector, VKpBR2.
[0263] The final expression vector hLL1pdHL2 was constructed by
sequentially subcloning the XbaI-BamHI and XhoI/BamHI fragments of
hLL1 VK and VH, respectively, into pdHL2. The pdHL2 vector is known
in the art (see, e.g., Gillies et al., 1989, J Immunol Methods
125:191). The pdHL2 vector provides expression of both IgG heavy
and light chain genes that are independently controlled by two
metallothionine promoters and IgH enhancers. Use of pdHL2 as an
expression vector for antibody production has been disclosed, for
example, in Losman et al., 1999, Clin Cancer Res 5:3101s-05s.
[0264] The fragment containing the VK sequence of hLL1, together
with the signal peptide sequence, was excised from LL1VKpBR2 by
double restriction digestion with XbaI and BamHI. The .about.550 bp
VK fragment was then subcloned into the XbaI/BamHI site of a
mammalian expression vector, pdHL2. The resulting vector was
designated as hLL1VKpdHL2. Similarly, the .about.750 bp fragment
encoding hLL1 VH, together with the signal peptide sequence, was
excised from LL1VHpBS2 by XhoI and BamHI digestion and isolated by
electrophoresis in an agarose gel. The fragment was subcloned into
the XhoI and HindIII site of hLL1VKpdHL2 with the aid of linker
comparable to both BamHI and HindIII ends, resulting in the final
expression vector, designated as hLL1pdHL2.
[0265] Approximately 30 .mu.g of hLL1pdHL2 was linearized by
digestion with Sal I and transfected into Sp2/0-Ag14 cells by
electroporation. The transfected cells were plated into 96-well
plate for 2 days and then selected for MTX resistance. Supernatants
from colonies surviving selection were monitored for chimeric
antibody secretion by ELISA assay. Positive cell clones were
expanded and hLL1 was purified from cell culture supernatant.
[0266] hLL2 Antibody
[0267] The hLL2 anti-CD22 antibody was prepared as described in
U.S. Pat. No. 6,187,287 (incorporated by reference from Col. 3,
line 35 to Col. 4, line 34 and Col. 11, line 40 to Col. 20, line
38, FIGS. 1, 4A, 4B, 5A, 5B). The variable region sequences of the
light and heavy chains of the hLL2 antibody are as described in
U.S. Pat. No. 6,187,287 (e.g., FIG. 1, FIG. 5). The LL2 antibody
was deposited on May 27, 2005, with the American Type Culture
Collection, Manassas, Va. (ATCC Accession No. PTA-6735), formerly
the EPB-2 monoclonal antibody, which was produced against human
Raji cells derived from a Burkitt lymphoma. (Pawlak-Byczkowska et
al., 1989, Cancer Res. 49:4568.) The cloning, transfection and
protein production were performed as described above for the hLL1
antibody.
[0268] hA20 Antibody
[0269] The hA20 anti-CD20 antibody was prepared as described in
U.S. Pat. No. 7,919,273 (incorporated by reference from Col. 7,
line 25 to Col. 9, line 4 and Col. 34, line 15 to Col. 72, line 2,
FIGS. 1A, 1B, 2A, 2B, 3A, 3B). The variable region sequences of the
light and heavy chains of the hA20 antibody are as described in
U.S. Pat. No. 7,919,273 (e.g., FIG. 2, FIG. 3). The cloning,
transfection and protein production were performed as described
above for the hLL1 antibody.
[0270] hL243 Antibody
[0271] The hL243 anti-HLA-DR antibody was prepared as described in
U.S. Pat. No. 7,612,180 (incorporated by reference from Col. 4,
line 16 to Col. 6, line 38 and Col. 46, line 50 to Col. 60, line
67, FIGS. 1 to 6). The variable region sequences of the light and
heavy chains of the hL243 antibody are as described in U.S. Pat.
No. 7,612,180 (e.g., FIG. 3, FIG. 4, FIG. 5, FIG. 6). The cloning,
transfection and protein production were performed as described
above for the hLL1 antibody.
[0272] Other known antibodies, such as hPAM4 (U.S. Pat. No.
7,282,567), hA19 (U.S. Pat. No. 7,109,304), hIMMU31 (U.S. Pat. No.
7,300,655), hMu-9 (U.S. Pat. No. 7,387,773), hMN-14 (U.S. Pat. No.
6,676,924), hMN-15 (U.S. Pat. No. 7,541,440), hR1 (U.S. patent
application Ser. No. 12/689,336), hRS7 (U.S. Pat. No. 7,238,785),
hMN-3 (U.S. Pat. No. 7,541,440), 15B8 (anti-CD40, U.S. Pat. No.
7,820,170), AB-PG1-XG1-026 (U.S. patent application Ser. No.
11/983,372, deposited as ATCC PTA-4405 and PTA-4406) and D2/B (WO
2009/130575), may be prepared as described above, using the
techniques disclosed herein.
Example 17. Preparation of Dock-and-Lock (DNL) Constructs
[0273] DDD and AD Fusion Proteins
[0274] The DNL technique can be used to make dimers, trimers,
tetramers, hexamers, etc. comprising virtually any antibody,
antibody fragment, immunomodulator, cytokine, enzyme, peptide, PEG
moiety, toxin, xenoantigen or other effector moiety. For certain
preferred embodiments, antibodies, cytokines or toxins (such as
ranpirnase) may be produced as fusion proteins comprising either a
dimerization and docking domain (DDD) or anchoring domain (AD)
sequence. Although in preferred embodiments the DDD and AD moieties
may be joined to antibodies, antibody fragments, cytokines, toxins
or other effector moieties as fusion proteins, the skilled artisan
will realize that other methods of conjugation exist, such as
chemical cross-linking, click chemistry reaction, etc.
[0275] The technique is not limiting and any protein or peptide of
use may be produced as an AD or DDD fusion protein for
incorporation into a DNL construct. Where chemical cross-linking is
utilized, the AD and DDD conjugates may comprise any molecule that
may be cross-linked to an AD or DDD sequence using any
cross-linking technique known in the art. In certain exemplary
embodiments, a dendrimer or other polymeric moiety such as
polyethyleneimine or polyethylene glycol (PEG), may be incorporated
into a DNL construct, as described in further detail below.
[0276] Expression Vectors
[0277] The plasmid vector pdHL2 has been used to produce a number
of antibodies and antibody-based constructs. See Gillies et al., J
Immunol Methods (1989), 125:191-202; Losman et al., Cancer (Phila)
(1997), 80:2660-6. The di-cistronic mammalian expression vector
directs the synthesis of the heavy and light chains of IgG. The
vector sequences are mostly identical for many different IgG-pdHL2
constructs, with the only differences existing in the variable
domain (V.sub.H and V.sub.L) sequences. Using molecular biology
tools known to those skilled in the art, these IgG expression
vectors can be converted into Fab-DDD or Fab-AD expression
vectors.
[0278] To generate Fab-DDD expression vectors, the coding sequences
for the hinge, CH2 and CH3 domains of the heavy chain were replaced
with a sequence encoding the first 4 residues of the hinge, a 14
residue Gly-Ser linker and a DDD moiety, such as the first 44
residues of human RII.alpha. (referred to as DDD1, SEQ ID NO:15).
To generate Fab-AD expression vectors, the sequences for the hinge,
CH2 and CH3 domains of IgG were replaced with a sequence encoding
the first 4 residues of the hinge, a 15 residue Gly-Ser linker and
an AD moiety, such as a 17 residue synthetic AD called AKAP-IS
(referred to as AD1, SEQ ID NO: 17), which was generated using
bioinformatics and peptide array technology and shown to bind
RII.alpha. dimers with a very high affinity (0.4 nM). See Alto, et
al. Proc. Natl. Acad. Sci., U.S.A (2003), 100:4445-50.
[0279] Two shuttle vectors were designed to facilitate the
conversion of IgG-pdHL2 vectors to either Fab-DDD1 or Fab-AD1
expression vectors, as described below.
[0280] Preparation of CH1
[0281] The CH1 domain was amplified by PCR using the pdHL2 plasmid
vector as a template. The left PCR primer consisted of the upstream
(5') end of the CH1 domain and a SacII restriction endonuclease
site, which is 5' of the CH1 coding sequence. The right primer
consisted of the sequence coding for the first 4 residues of the
hinge followed by four glycines and a serine, with the final two
codons (GS) comprising a Bam HI restriction site. The 410 bp PCR
amplimer was cloned into the PGEMT.RTM. PCR cloning vector
(PROMEGA.RTM., Inc.) and clones were screened for inserts in the T7
(5') orientation.
[0282] A duplex oligonucleotide was synthesized to code for the
amino acid sequence of DDD1 preceded by 11 residues of the linker
peptide, with the first two codons comprising a BamHI restriction
site. A stop codon and an EagI restriction site are appended to the
3'end. The encoded polypeptide sequence is shown below.
TABLE-US-00024 (SEQ ID NO: 137)
GSGGGGSGGGGSHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFTRL REARA
[0283] Two oligonucleotides, designated RIIA1-44 top and RIIA1-44
bottom, which overlap by 30 base pairs on their 3' ends, were
synthesized and combined to comprise the central 154 base pairs of
the 174 bp DDD1 sequence. The oligonucleotides were annealed and
subjected to a primer extension reaction with Taq polymerase.
Following primer extension, the duplex was amplified by PCR. The
amplimer was cloned into PGEMT.RTM. and screened for inserts in the
T7 (5') orientation.
[0284] A duplex oligonucleotide was synthesized to code for the
amino acid sequence of AD1 preceded by 11 residues of the linker
peptide with the first two codons comprising a BamHI restriction
site. A stop codon and an EagI restriction site are appended to the
3'end. The encoded polypeptide sequence is shown below.
TABLE-US-00025 (SEQ ID NO: 138) GSGGGGSGGGGSQIEYLAKQIVDNAIQQA
[0285] Two complimentary overlapping oligonucleotides encoding the
above peptide sequence, designated AKAP-IS Top and AKAP-IS Bottom,
were synthesized and annealed. The duplex was amplified by PCR. The
amplimer was cloned into the PGEMT.RTM. vector and screened for
inserts in the T7 (5') orientation.
[0286] Ligating DDD1 with CH1
[0287] A 190 bp fragment encoding the DDD1 sequence was excised
from PGEMT.RTM. with BamHI and NotI restriction enzymes and then
ligated into the same sites in CH1-PGEMT.RTM. to generate the
shuttle vector CH1-DDD1-PGEMT.RTM..
[0288] Ligating AD1 with CH1
[0289] A 110 bp fragment containing the AD1 sequence was excised
from PGEMT.RTM. with BamHI and NotI and then ligated into the same
sites in CH1-PGEMT.RTM. to generate the shuttle vector
CH1-AD1-PGEMT.RTM..
[0290] Cloning CH1-DDD1 or CH1-AD1 into pdHL2-Based Vectors
[0291] With this modular design either CH1-DDD1 or CH1-AD1 can be
incorporated into any IgG construct in the pdHL2 vector. The entire
heavy chain constant domain is replaced with one of the above
constructs by removing the SacII/EagI restriction fragment
(CH1-CH3) from pdHL2 and replacing it with the SacII/EagI fragment
of CH1-DDD1 or CH1-AD1, which is excised from the respective
PGEMT.RTM. shuttle vector.
[0292] Construction of h679-Fd-AD1-pdHL2
[0293] h679-Fd-AD1-pdHL2 is an expression vector for production of
h679 Fab with AD1 coupled to the carboxyl terminal end of the CH1
domain of the Fd via a flexible Gly/Ser peptide spacer composed of
14 amino acid residues. A pdHL2-based vector containing the
variable domains of h679 was converted to h679-Fd-AD1-pdHL2 by
replacement of the SacII/EagI fragment with the CH1-AD1 fragment,
which was excised from the CH1-AD1-SV3 shuttle vector with SacII
and EagI.
[0294] Production and Purification of h679-Fab-AD1
[0295] The h679-Fd-AD1-pdHL2 vector was linearized by digestion
with Sal I restriction endonuclease and transfected into Sp/EEE
myeloma cells (U.S. Pat. No. 7,785,880) by electroporation. The
di-cistronic expression vector directs the synthesis and secretion
of both h679 kappa light chain and h679 Fd-AD1, which combine to
form h679 Fab-AD1. Following electroporation, the cells were plated
in 96-well tissue culture plates and transfectant clones were
selected with 0.05 .mu.M methotrexate (MTX). Clones were screened
for protein expression by ELISA using microtiter plates coated with
a BSA-IMP260 (HSG) conjugate and detection with HRP-conjugated goat
anti-human Fab. BIACORE.RTM. analysis using an HSG (IMP239) sensor
chip was used to determine the productivity by measuring the
initial slope obtained from injection of diluted media samples. The
highest producing clone had an initial productivity of
approximately 30 mg/L. A total of 230 mg of h679-Fab-AD1 was
purified from 4.5 liters of roller bottle culture by single-step
IMP291 affinity chromatography. Culture media was concentrated
approximately 10-fold by ultrafiltration before loading onto an
IMP29-affigel column. The column was washed to baseline with PBS
and h679-Fab-AD1 was eluted with 1 M imidazole, 1 mM EDTA, 0.1 M
NaAc, pH 4.5. SE-HPLC analysis of the eluate shows a single sharp
peak with a retention time consistent with a 50 kDa protein (not
shown). Only two bands, which represent the polypeptide
constituents of h679-AD1, were evident by reducing SDS-PAGE
analysis (not shown).
[0296] Construction of C-DDD1-Fd-hMN-14-pdHL2
[0297] C-DDD1-Fd-hMN-14-pdHL2 is an expression vector for
production of a stable dimer that comprises two copies of a fusion
protein C-DDD1-Fab-hMN-14, in which DDD1 is linked to hMN-14 Fab at
the carboxyl terminus of CH1 via a flexible peptide spacer. The
plasmid vector hMN-14(I)-pdHL2, which has been used to produce
hMN-14 IgG, was converted to C-DDD1-Fd-hMN-14-pdHL2 by digestion
with SacII and EagI restriction endonucleases to remove the CH1-CH3
domains and insertion of the CH1-DDD1 fragment, which was excised
from the CH1-DDD1-SV3 shuttle vector with SacII and EagI.
[0298] The same technique has been utilized to produce plasmids for
Fab expression of a wide variety of known antibodies, such as hLL1,
hLL2, hPAM4, hR1, hRS7, hMN-14, hMN-15, hA19, hA20 and many others.
Generally, the antibody variable region coding sequences were
present in a pdHL2 expression vector and the expression vector was
converted for production of an AD- or DDD-fusion protein as
described above. The AD- and DDD-fusion proteins comprising a Fab
fragment of any of such antibodies may be combined, in an
approximate ratio of two DDD-fusion proteins per one AD-fusion
protein, to generate a trimeric DNL construct comprising two Fab
fragments of a first antibody and one Fab fragment of a second
antibody.
[0299] Production and Purification of C-DDD1-Fab-hMN-14
[0300] The C-DDD1-Fd-hMN-14-pdHL2 vector was transfected into
Sp2/0-derived myeloma cells by electroporation.
C-DDD1-Fd-hMN-14-pdHL2 is a di-cistronic expression vector, which
directs the synthesis and secretion of both hMN-14 kappa light
chain and hMN-14 Fd-DDD1, which combine to form C-DDD1-hMN-14 Fab.
The fusion protein forms a stable homodimer via the interaction of
the DDD1 domain.
[0301] Following electroporation, the cells were plated in 96-well
tissue culture plates and transfectant clones were selected with
0.05 .mu.M methotrexate (MTX). Clones were screened for protein
expression by ELISA using microtiter plates coated with WI2 (a rat
anti-id monoclonal antibody to hMN-14) and detection with
HRP-conjugated goat anti-human Fab. The initial productivity of the
highest producing C-DDD1-Fab-hMN14 Fab clone was 60 mg/L.
[0302] Affinity Purification of C-DDD1-hMN-14 with AD1-Affigel
[0303] The DDD/AD interaction was utilized to affinity purify
DDD-containing constructs. AD1-C is a peptide that was made
synthetically consisting of the AD1 sequence and a carboxyl
terminal cysteine residue, which was used to couple the peptide to
Affigel following reaction of the sulfhydryl group with
chloroacetic anhydride. DDD-containing dimer structures
specifically bind to the AD1-C-Affigel resin at neutral pH and can
be eluted at low pH (e.g., pH 2.5).
[0304] A total of 81 mg of C-DDD1-Fab-hMN-14 was purified from 1.2
liters of roller bottle culture by single-step AD1-C affinity
chromatography. Culture media was concentrated approximately
10-fold by ultrafiltration before loading onto an AD1-C-affigel
column. The column was washed to baseline with PBS and
C-DDD1-Fab-hMN-14 was eluted with 0.1 M Glycine, pH 2.5. SE-HPLC
analysis of the eluate showed a single protein peak with a
retention time consistent with a 107 kDa protein (not shown). The
purity was also confirmed by reducing SDS-PAGE, showing only two
bands of molecular size expected for the two polypeptide
constituents of C-DDD1-Fab-hMN-14 (not shown).
[0305] The binding activity of C-DDD1-Fab-hMN-14 was determined by
SE-HPLC analysis of samples in which the test article was mixed
with various amounts of WI2. A sample prepared by mixing WI2 Fab
and C-DDD1-Fab-hMN-14 at a molar ratio of 0.75:1 showed three
peaks, which were attributed to unbound C-DDD1-Fab-hMN14 (8.71
min), C-DDD1-Fab-hMN-14 bound to one WI2 Fab (7.95 min), and
C-DDD1-Fab-hMN14 bound to two WI2 Fabs (7.37 min) (not shown). When
a sample containing WI2 Fab and C-DDD1-Fab-hMN-14 at a molar ratio
of 4 was analyzed, only a single peak at 7.36 minutes was observed
(not shown). These results demonstrated that hMN14-Fab-DDD1 is
dimeric and has two active binding sites. Very similar results were
obtained when this experiment was repeated with an hMN-14 Fab
construct with DDD1 linked to the amino terminal instead of the
carboxyl terminal end (not shown).
[0306] A competitive ELISA demonstrated that C-DDD1-Fab-hMN-14
binds to CEA with an avidity similar to hMN-14 IgG, and
significantly stronger than monovalent hMN-14 Fab (not shown).
ELISA plates were coated with a fusion protein containing the
epitope (A3B3) of CEA for which hMN-14 is specific.
[0307] C-DDD2-Fd-hMN-14-pdHL2
[0308] C-DDD2-Fd-hMN-14-pdHL2 is an expression vector for
production of C-DDD2-Fab-hMN-14, which possesses a dimerization and
docking domain sequence of DDD2 (SEQ ID NO:16) appended to the
carboxyl terminus of the Fd of hMN-14 via a 14 amino acid residue
Gly/Ser peptide linker. The fusion protein secreted is composed of
two identical copies of hMN-14 Fab held together by non-covalent
interaction of the DDD2 domains.
[0309] The expression vector was engineered as follows. Two
overlapping, complimentary oligonucleotides, which comprise the
coding sequence for part of the linker peptide and residues 1-13 of
DDD2, were made synthetically. The oligonucleotides were annealed
and phosphorylated with T4 PNK, resulting in overhangs on the 5'
and 3' ends that are compatible for ligation with DNA digested with
the restriction endonucleases BamHI and PstI, respectively.
[0310] The duplex DNA was ligated with the shuttle vector
CH1-DDD1-PGEMT.RTM., which was prepared by digestion with BamHI and
PstI, to generate the shuttle vector CH1-DDD2-PGEMT.RTM.. A 507 bp
fragment was excised from CH1-DDD2-PGEMT.RTM. with SacII and EagI
and ligated with the IgG expression vector hMN-14(I)-pdHL2, which
was prepared by digestion with SacII and EagI. The final expression
construct was designated C-DDD2-Fd-hMN-14-pdHL2. Similar techniques
have been utilized to generated DDD2-fusion proteins of the Fab
fragments of a number of different humanized antibodies.
[0311] h679-Fd-AD2-pdHL2
[0312] h679-Fab-AD2, was designed to pair to C-DDD2-Fab-hMN-14.
h679-Fd-AD2-pdHL2 is an expression vector for the production of
h679-Fab-AD2, which possesses an anchoring domain sequence of AD2
(SEQ ID NO:18) appended to the carboxyl terminal end of the CH1
domain via a 14 amino acid residue Gly/Ser peptide linker. AD2 has
one cysteine residue preceding and another one following the anchor
domain sequence of AD1.
[0313] The expression vector was engineered as follows. Two
overlapping, complimentary oligonucleotides (AD2 Top and AD2
Bottom), which comprise the coding sequence for AD2 and part of the
linker sequence, were made synthetically. The oligonucleotides were
annealed and phosphorylated with T4 PNK, resulting in overhangs on
the 5' and 3' ends that are compatible for ligation with DNA
digested with the restriction endonucleases BamHI and SpeI,
respectively.
[0314] The duplex DNA was ligated into the shuttle vector
CH1-AD1-PGEMT.RTM., which was prepared by digestion with BamHI and
SpeI, to generate the shuttle vector CH1-AD2-PGEMT.RTM.. A 429 base
pair fragment containing CH1 and AD2 coding sequences was excised
from the shuttle vector with SacII and EagI restriction enzymes and
ligated into h679-pdHL2 vector that prepared by digestion with
those same enzymes. The final expression vector is
h679-Fd-AD2-pdHL2.
Example 18. Generation of Trimeric DNL Constructs
[0315] TF2 DNL Construct
[0316] A trimeric DNL construct designated TF2 was obtained by
reacting C-DDD2-Fab-hMN-14 with h679-Fab-AD2. A pilot batch of TF2
was generated with >90% yield as follows. Protein L-purified
C-DDD2-Fab-hMN-14 (200 mg) was mixed with h679-Fab-AD2 (60 mg) at a
1.4:1 molar ratio. The total protein concentration was 1.5 mg/ml in
PBS containing 1 mM EDTA. Subsequent steps involved TCEP reduction,
HIC chromatography, DMSO oxidation, and IMP 291 affinity
chromatography. Before the addition of TCEP, SE-HPLC did not show
any evidence of a.sub.2b formation. Addition of 5 mM TCEP rapidly
resulted in the formation of a.sub.2b complex consistent with a 157
kDa protein expected for the binary structure. TF2 was purified to
near homogeneity by IMP 291 affinity chromatography (not shown).
IMP 291 is a synthetic peptide containing the HSG hapten to which
the 679 Fab binds (Rossi et al., 2005, Clin Cancer Res
11:7122s-29s). SE-HPLC analysis of the IMP 291 unbound fraction
demonstrated the removal of a.sub.4, a.sub.2 and free kappa chains
from the product (not shown).
[0317] The functionality of TF2 was determined by BIACORE.RTM.
assay. TF2, C-DDD1-hMN-14+h679-AD1 (used as a control sample of
noncovalent a.sub.2b complex), or C-DDD2-hMN-14+h679-AD2 (used as a
control sample of unreduced a.sub.2 and b components) were diluted
to 1 .mu.g/ml (total protein) and passed over a sensorchip
immobilized with HSG. The response for TF2 was approximately
two-fold that of the two control samples, indicating that only the
h679-Fab-AD component in the control samples would bind to and
remain on the sensorchip. Subsequent injections of WI2 IgG, an
anti-idiotype antibody for hMN-14, demonstrated that only TF2 had a
DDD-Fab-hMN-14 component that was tightly associated with
h679-Fab-AD as indicated by an additional signal response. The
additional increase of response units resulting from the binding of
WI2 to TF2 immobilized on the sensorchip corresponded to two fully
functional binding sites, each contributed by one subunit of
C-DDD2-Fab-hMN-14. This was confirmed by the ability of TF2 to bind
two Fab fragments of WI2 (not shown).
[0318] TF10 DNL Construct
[0319] A similar protocol was used to generate a trimeric TF10 DNL
construct, comprising two copies of a C-DDD2-Fab-hPAM4 and one copy
of C-AD2-Fab-679. The TF10 bispecific ([hPAM4].sub.2.times.h679)
antibody was produced using the method disclosed for production of
the (anti CEA).sub.2.times.anti HSG bsAb TF2, as described above.
The TF10 construct bears two humanized PAM4 Fabs and one humanized
679 Fab.
[0320] The two fusion proteins (hPAM4-DDD2 and h679-AD2) were
expressed independently in stably transfected myeloma cells. The
tissue culture supernatant fluids were combined, resulting in a
two-fold molar excess of hPAM4-DDD2. The reaction mixture was
incubated at room temperature for 24 hours under mild reducing
conditions using 1 mM reduced glutathione. Following reduction, the
DNL reaction was completed by mild oxidation using 2 mM oxidized
glutathione. TF10 was isolated by affinity chromatography using
IMP291-affigel resin, which binds with high specificity to the h679
Fab.
Example 19. Production of AD- and DDD-Linked Fab and IgG Fusion
Proteins from Multiple Antibodies
[0321] Using the techniques described in the preceding Examples,
the IgG and Fab fusion proteins shown in Table 7 were constructed
and incorporated into DNL constructs. The fusion proteins retained
the antigen-binding characteristics of the parent antibodies and
the DNL constructs exhibited the antigen-binding activities of the
incorporated antibodies or antibody fragments.
TABLE-US-00026 TABLE 7 Fusion proteins comprising IgG or Fab Fusion
Protein Binding Specificity C-AD1-Fab-h679 HSG C-AD2-Fab-h679 HSG
C-(AD).sub.2-Fab-h679 HSG C-AD2-Fab-h734 Indium-DTPA C-AD2-Fab-hA20
CD20 C-AD2-Fab-hA20L CD20 C-AD2-Fab-hL243 HLA-DR C-AD2-Fab-hLL2
CD22 N-AD2-Fab-hLL2 CD22 C-AD2-IgG-hMN-14 CEACAM5 C-AD2-IgG-hR1
IGF-1R C-AD2-IgG-hRS7 EGP-1 C-AD2-IgG-hPAM4 MUC C-AD2-IgG-hLL1 CD74
C-DDD1-Fab-hMN-14 CEACAM5 C-DDD2-Fab-hMN-14 CEACAM5 C-DDD2-Fab-h679
HSG C-DDD2-Fab-hA19 CD19 C-DDD2-Fab-hA20 CD20 C-DDD2-Fab-hAFP AFP
C-DDD2-Fab-hL243 HLA-DR C-DDD2-Fab-hLL1 CD74 C-DDD2-Fab-hLL2 CD22
C-DDD2-Fab-hMN-3 CEACAM6 C-DDD2-Fab-hMN-15 CEACAM6 C-DDD2-Fab-hPAM4
MUC C-DDD2-Fab-hR1 IGF-1R C-DDD2-Fab-hRS7 EGP-1 N-DDD2-Fab-hMN-14
CEACAM5
Example 20. Antibody-Dendrimer DNL Complex for sIRNA
[0322] Cationic polymers, such as polylysine, polyethylenimine, or
polyamidoamine (PAMAM)-based dendrimers, form complexes with
nucleic acids. However, their potential applications as non-viral
vectors for delivering therapeutic genes or siRNAs remain a
challenge. One approach to improve selectivity and potency of a
dendrimeric nanoparticle may be achieved by conjugation with an
antibody that internalizes upon binding to target cells.
[0323] We synthesized and characterized a novel immunoconjugate,
designated E1-G5/2, which was made by the DNL method to comprise
half of a generation 5 (05) PAMAM dendrimer (G5/2)
site-specifically linked to a stabilized dimer of Fab derived from
hRS7, a humanized antibody that is rapidly internalized upon
binding to the Trop-2 antigen expressed on various solid
cancers.
[0324] Methods
[0325] E1-G5/2 was prepared by combining two self-assembling
modules, AD2-G5/2 and hRS7-Fab-DDD2, under mild redox conditions,
followed by purification on a Protein L column. To make AD2-G5/2,
we derivatized the AD2 peptide with a maleimide group to react with
the single thiol generated from reducing a G5 PAMAM with a
cystamine core and used reversed-phase HPLC to isolate AD2-G5/2. We
produced hRS7-Fab-DDD2 as a fusion protein in myeloma cells, as
described in the Examples above.
[0326] The molecular size, purity and composition of E1-G5/2 were
analyzed by size-exclusion HPLC, SDS-PAGE, and Western blotting.
The biological functions of E1-G5/2 were assessed by binding to an
anti-idiotype antibody against hRS7, a gel retardation assay, and a
DNase protection assay.
[0327] Results
[0328] E1-G5/2 was shown by size-exclusion HPLC to consist of a
major peak (>90%) flanked by several minor peaks (not shown).
The three constituents of E1-G5/2 (Fd-DDD2, the light chain, and
AD2-G5/2) were detected by reducing SDS-PAGE and confirmed by
Western blotting (not shown). Anti-idiotype binding analysis
revealed E1-G5/2 contained a population of antibody-dendrimer
conjugates of different size, all of which were capable of
recognizing the anti-idiotype antibody, thus suggesting structural
variability in the size of the purchased G5 dendrimer (not shown).
Gel retardation assays showed E1-G5/2 was able to maximally
condense plasmid DNA at a charge ratio of 6:1 (+/-), with the
resulting dendriplexes completely protecting the complexed DNA from
degradation by DNase I (not shown).
[0329] Conclusion
[0330] The DNL technique can be used to build dendrimer-based
nanoparticles that are targetable with antibodies. Such agents have
improved properties as carriers of drugs, plasmids or siRNAs for
applications in vitro and in vivo. In preferred embodiments,
anti-B-cell antibodies, such as anti-CD22 and/or anti-CD20, may be
utilized to deliver cytotoxic or cytostatic siRNA species to
targeted B-cells for therapy of lymphoma, leukemia, autoimmune or
other diseases and conditions.
Example 21. Targeted Delivery of siRNA Using Protamine Linked
Antibodies
[0331] Summary
[0332] RNA interference (RNAi) has been shown to down-regulate the
expression of various proteins such as HER2, VEGF, Raf-1, bcl-2,
EGFR and numerous others in preclinical studies. Despite the
potential of RNAi to silence specific genes, the full therapeutic
potential of RNAi remains to be realized due to the lack of an
effective delivery system to target cells in vivo.
[0333] To address this critical need, we developed novel DNL
constructs having multiple copies of human protamine tethered to a
tumor-targeting, internalizing hRS7 (anti-Trop-2) antibody for
targeted delivery of siRNAs in vivo. A DDD2-L-thP1 module
comprising truncated human protamine (thP1, residues 8 to 29 of
human protamine 1) was produced, in which the sequences of DDD2 and
thP1 were fused respectively to the N- and C-terminal ends of a
humanized antibody light chain (not shown). The sequence of the
truncated hP1 (thP1) is shown below. Reaction of DDD2-L-thP1 with
the antibody hRS7-IgG-AD2 under mild redox conditions, as described
in the Examples above, resulted in the formation of an E1-L-thP1
complex (not shown), comprising four copies of thP1 attached to the
carboxyl termini of the hRS7 heavy chains.
TABLE-US-00027 tHP1 (SEQ ID NO: 139) RSQSRSRYYRQRQRSRRRRRRS
[0334] The purity and molecular integrity of E1-L-thP1 following
Protein A purification were determined by size-exclusion HPLC and
SDS-PAGE (not shown). In addition, the ability of E1-L-thP1 to bind
plasmid DNA or siRNA was demonstrated by the gel shift assay (not
shown). E1-L-thP1 was effective at binding short double-stranded
oligonucleotides (not shown) and in protecting bound DNA from
digestion by nucleases added to the sample or present in serum (not
shown).
[0335] The ability of the E1-L-thP1 construct to internalize siRNAs
into Trop-2-expressing cancer cells was confirmed by fluorescence
microscopy using FITC-conjugated siRNA and the human Calu-3 lung
cancer cell line (not shown).
[0336] Methods
[0337] The DNL technique was employed to generate E1-L-thP1. The
hRS7 IgG-AD module, constructed as described in the Examples above,
was expressed in myeloma cells and purified from the culture
supernatant using Protein A affinity chromatography. The
DDD2-L-thP1 module was expressed as a fusion protein in myeloma
cells and was purified by Protein L affinity chromatography. Since
the CH3-AD2-IgG module possesses two AD2 peptides and each can bind
to a DDD2 dimer, with each DDD2 monomer attached to a protamine
moiety, the resulting E1-L-thP1 conjugate comprises four protamine
groups. E1-L-thp1 was formed in nearly quantitative yield from the
constituent modules and was purified to near homogeneity (not
shown) with Protein A.
[0338] DDD2-L-thP1 was purified using Protein L affinity
chromatography and assessed by size exclusion HPLC analysis and
SDS-PAGE under reducing and nonreducing conditions (data not
shown). A major peak was observed at 9.6 min (not shown). SDS-PAGE
showed a major band between 30 and 40 kDa in reducing gel and a
major band about 60 kDa (indicating a dimeric form of DDD2-L-thP1)
in nonreducing gel (not shown). The results of Western blotting
confirmed the presence of monomeric DDD2-L-tP1 and dimeric
DDD2-L-tP1 on probing with anti-DDD antibodies (not shown).
[0339] To prepare the E1-L-thP1, hRS7-IgG-AD2 and DDD2-L-thP1 were
combined in approximately equal amounts and reduced glutathione
(final concentration 1 mM) was added. Following an overnight
incubation at room temperature, oxidized glutathione was added
(final concentration 2 mM) and the incubation continued for another
24 h. E1-L-thP1 was purified from the reaction mixture by Protein A
column chromatography and eluted with 0.1 M sodium citrate buffer
(pH 3.5). The product peak (not shown) was neutralized,
concentrated, dialyzed with PBS, filtered, and stored in PBS
containing 5% glycerol at 2 to 8.degree. C. The composition of
E1-L-thP1 was confirmed by reducing SDS-PAGE (not shown), which
showed the presence of all three constituents (AD2-appended heavy
chain, DDD2-L-htP1, and light chain).
[0340] The ability of DDD2-L-thP1 and E1-L-thP1 to bind DNA was
evaluated by gel shift assay. DDD2-L-thP1 retarded the mobility of
500 ng of a linear form of 3-kb DNA fragment in 1% agarose at a
molar ratio of 6 or higher (not shown). E1-L-thP1 retarded the
mobility of 250 ng of a linear 200-bp DNA duplex in 2% agarose at a
molar ratio of 4 or higher (not shown), whereas no such effect was
observed for hRS7-IgG-AD2 alone (not shown). The ability of
E1-L-thP1 to protect bound DNA from degradation by exogenous DNase
and serum nucleases was also demonstrated (not shown).
[0341] The ability of E1-L-thP1 to promote internalization of bound
siRNA was examined in the Trop-2 expressing ME-180 cervical cell
line (not shown). Internalization of the E1-L-thP1 complex was
monitored using FITC conjugated goat anti-human antibodies. The
cells alone showed no fluorescence (not shown). Addition of
FITC-labeled siRNA alone resulted in minimal internalization of the
siRNA (not shown). Internalization of E1-L-thP1 alone was observed
in 60 minutes at 37.degree. C. (not shown). E1-L-thP1 was able to
effectively promote internalization of bound FITC-conjugated siRNA
(not shown). E1-L-thP1 (10 .mu.g) was mixed with FITC-siRNA (300
nM) and allowed to form E1-L-thP1-siRNA complexes which were then
added to Trop-2-expressing Calu-3 cells. After incubation for 4 h
at 37.degree. C. the cells were checked for internalization of
siRNA by fluorescence microscopy (not shown).
[0342] The ability of E1-L-thP1 to induce apoptosis by
internalization of siRNA was examined. E1-L-thP1 (10 .mu.g) was
mixed with varying amounts of siRNA (AllStars Cell Death siRNA,
Qiagen, Valencia, Calif.). The E1-L-thP1-siRNA complex was added to
ME-180 cells. After 72 h of incubation, cells were trypsinized and
annexin V staining was performed to evaluate apoptosis. The Cell
Death siRNA alone or E1-L-thP1 alone had no effect on apoptosis
(not shown). Addition of increasing amounts of E1-L-thP1-siRNA
produced a dose-dependent increase in apoptosis (not shown). These
results show that E1-L-thP1 could effectively deliver siRNA
molecules into the cells and induce apoptosis of target cells.
[0343] Conclusions
[0344] The DNL technology provides a modular approach to
efficiently tether multiple protamine molecules to the anti-Trop-2
hRS7 antibody resulting in the novel molecule E1-L-thP1. SDS-PAGE
demonstrated the homogeneity and purity of E1-L-thP1. DNase
protection and gel shift assays showed the DNA binding activity of
E1-L-thP1. E1-L-thP1 internalized in the cells like the parental
hRS7 antibody and was able to effectively internalize siRNA
molecules into Trop-2-expressing cells, such as ME-180 and
Calu-3.
[0345] The skilled artisan will realize that the DNL technique is
not limited to any specific antibody or siRNA species. Rather, the
same methods and compositions demonstrated herein can be used to
make targeted delivery complexes comprising any antibody, any siRNA
carrier and any siRNA species. The use of a bivalent IgG in
targeted delivery complexes would result in prolonged circulating
half-life and higher binding avidity to target cells, resulting in
increased uptake and improved efficacy.
Example 22. Ribonuclease Based DNL Immunotoxins Comprising
Quadruple Ranpirnase (Rap) Conjugated to B-Cell Targeting
Antibodies
[0346] We applied the DNL method to generate a novel class of
immunotoxins, each of which comprises four copies of Rap
site-specifically linked to a bivalent IgG. We combined a
recombinant Rap-DDD module, produced in E. coli, with recombinant,
humanized IgG-AD modules, which were produced in myeloma cells and
targeted B-cell lymphomas and leukemias via binding to CD20 (hA20,
veltuzumab), CD22 (hLL2, epratuzumab) or HLA-DR (hL243, IMMU-114),
to generate 20-Rap, 22-Rap and C2-Rap, respectively. For each
construct, a dimer of Rap was covalently tethered to the C-terminus
of each heavy chain of the respective IgG. A control construct,
14-Rap, was made similarly, using labetuzumab (hMN-14), that binds
to an antigen (CEACAM5) not expressed on B-cell
lymphomas/leukemias.
TABLE-US-00028 Rap-DDD2 (SEQ ID NO: 140)
pQDWLTFQKKHITNTRDVDCDNIMSTNLFHCKDKNTFIYSRPEPVKAICK
GIIASKNVLTTSEFYLSDCNVTSRPCKYKLKKSTNKFCVTCENQAPVHFV
GVGSCGGGGSLECGHIQIPPGLTELLQGYTVEVLRQQPPDLVEFAVEYFT
RLREARAVEHHHHHH
[0347] The deduced amino acid sequence of secreted Rap-DDD2 is
shown above (SEQ ID NO:140). Rap, underlined; linker, italics;
DDD2, bold; pQ, amino-terminal glutamine converted to
pyroglutamate. Rap-DDD2 was produced in E. coli as inclusion
bodies, which were purified by IMAC under denaturing conditions,
refolded and then dialyzed into PBS before purification by anion
exchange chromatography. SDS-PAGE under reducing conditions
resolved a protein band with a Mr appropriate for Rap-DDD2 (18.6
kDa) (not shown). The final yield of purified Rap-DDD2 was 10 mg/L
of culture.
[0348] The DNL method was employed to rapidly generate a panel of
IgG-Rap conjugates. The IgG-AD modules were expressed in myeloma
cells and purified from the culture supernatant using Protein A
affinity chromatography. The Rap-DDD2 module was produced and mixed
with IgG-AD2 to form a DNL complex. Since the CH3-AD2-IgG modules
possess two AD2 peptides and each can tether a Rap dimer, the
resulting IgG-Rap DNL construct comprises four Rap groups and one
IgG. IgG-Rap is formed nearly quantitatively from the constituent
modules and purified to near homogeneity with Protein A.
[0349] Prior to the DNL reaction, the CH3-AD2-IgG exists as both a
monomer, and a disulfide-linked dimer (not shown). Under
non-reducing conditions, the IgG-Rap resolves as a cluster of high
molecular weight bands of the expected size between those for
monomeric and dimeric CH3-AD2-IgG (not shown). Reducing conditions,
which reduces the conjugates to their constituent polypeptides,
show the purity of the IgG-Rap and the consistency of the DNL
method, as only bands representing heavy-chain-AD2 (HC-AD2), kappa
light chain and Rap-DDD2 were visualized (not shown). Reversed
phase HPLC analysis of 22-Rap (not shown) resolved a single protein
peak at 9.10 min eluting between the two peaks of CH3-AD2-IgG-hLL2,
representing the monomeric (7.55 min) and the dimeric (8.00 min)
forms. The Rap-DDD2 module was isolated as a mixture of dimer and
tetramer (reduced to dimer during DNL), which were eluted at 9.30
and 9.55 min, respectively (not shown).
[0350] LC/MS analysis of 22-Rap (not shown) showed that both the
Rap-DDD2 and HC-AD2 polypeptides have an amino terminal glutamine
that is converted to pyroglutamate (pQ) and that 22-Rap has 6 of
its 8 constituent polypeptides modified by pQ.
[0351] In vitro cytotoxicity was evaluated in three NHL cell lines.
Each cell line expresses CD20 at a considerably higher surface
density compared to CD22; however, the internalization rate for
hLL2 (anti-CD22) is much faster than hA20 (anti-CD20). 14-Rap
shares the same structure as 22-Rap and 20-Rap, but its antigen
(CEACAM5) is not expressed by the NHL cells. Cells were treated
continuously with IgG-Rap as single agents or with combinations of
the parental MAbs plus rRap. Both 20-Rap and 22-Rap killed each
cell line at concentrations above 1 nM, indicating that their
action is cytotoxic as opposed to merely cytostatic (not shown).
20-Rap was the most potent IgG-Rap, suggesting that antigen density
may be more important than internalization rate. Similar results
were obtained for Daudi and Ramos, where 20-Rap (EC50.about.0.1 nM)
was 3-6-fold more potent than 22-Rap (not shown). The
rituximab-resistant mantle cell lymphoma line, Jeko-1, exhibits
increased CD20 but decreased CD22, compared to Daudi and Ramos.
Importantly, 20-Rap exhibited very potent cytotoxicity
(EC.sub.50.about.20 pM) in Jeko-1, which was 25-fold more potent
than 22-Rap (not shown).
[0352] The DNL method provides a modular approach to efficiently
tether multiple cytotoxins onto a targeting antibody, resulting in
novel immunotoxins that are expected to show higher in vivo potency
due to improved pharmacokinetics and targeting specificity.
Targeting Rap with a MAb to a cell surface antigen enhanced its
tumor-specific cytotoxicity. Antigen density and internalization
rate are both critical factors for the observed in vitro potency of
IgG-Rap. In vitro results show that CD20-, CD22-, or
HLA-DR-targeted IgG-Rap have potent biologic activity for therapy
of B-cell lymphomas and leukemias. The skilled artisan will realize
that the modular DNL technique may be utilized to produce Rap DNL
constructs targeted to CD22.
Example 23. Production and Use of a DNL Construct Comprising Two
Different Antibody Moieties and a Cytokine
[0353] In certain embodiments, trimeric DNL constructs may comprise
three different effector moieties, for example two different
antibody moieties and a cytokine moiety. We report here the
generation and characterization of the first bispecific
MAb-IFN.alpha., designated 20-C2-2b, which comprises two copies of
IFN-.alpha.2b and a stabilized F(ab).sub.2 of hL243 (humanized
anti-HLA-DR; IMMU-114) site-specifically linked to veltuzumab
(humanized anti-CD20). In vitro, 20-C2-2b inhibited each of four
lymphoma and eight myeloma cell lines, and was more effective than
monospecific CD20-targeted MAb-IFN.alpha. or a mixture comprising
the parental antibodies and IFN.alpha. in all but one
(HLA-DR.sup.-/CD20.sup.-) myeloma line (not shown), suggesting that
20-C2-2b should be useful in the treatment of various hematopoietic
disorders. The 20-C2-2b displayed greater cytotoxicity against
KMS12-BM (CD20.sup.+/HLA-DR.sup.+ myeloma) than monospecific
MAb-IFN.alpha. that targets only HLA-DR or CD20 (not shown),
indicating that all three components in 20-C2-2b can contribute to
toxicity. Our findings indicate that a given cell's responsiveness
to MAb-IFN.alpha. depends on its sensitivity to IFN.alpha. and the
specific antibodies, as well as the expression and density of the
targeted antigens.
[0354] Because 20-C2-2b has antibody-dependent cellular
cytotoxicity (ADCC), but not CDC, and can target both CD20 and
HLA-DR, it is useful for therapy of a broad range of hematopoietic
disorders that express either or both antigens.
[0355] Antibodies
[0356] The abbreviations used in the following discussion are: 20
(C.sub.H3-AD2-IgG-v-mab, anti-CD20 IgG DNL module); C2
(C.sub.H1-DDD2-Fab-hL243, anti-HLA-DR Fab.sub.2 DNL module); 2b
(dimeric IFN.alpha.2B-DDD2 DNL module); 734 (anti-in-DTPA IgG DNL
module used as non-targeting control). The following MAbs were
provided by Immunomedics, Inc.: veltuzumab or v-mab (anti-CD)20
IgG.sub.1), hL243.gamma.4p (Immu-114, anti-HLA-DR IgG.sub.4), a
murine anti-IFN.alpha. MAb, and rat anti-idiotype MAbs to v-mab
(WR2) and hL243 (WT).
[0357] DNL Constructs
[0358] Monospecific MAb-IFN.alpha. (20-2b-2b, 734-2b-2b and
C2-2b-2b) and the bispecific HexAb (20-C2-C2) were generated by
combination of an IgG-AD2-module with DDD2-modules using the DNL
method, as described in the preceding Examples. The 734-2b-2b,
which comprises tetrameric IFN.alpha.2b and MAb h734
[anti-Indium-DTPA IgG.sub.1], was used as a non-targeting control
MAb-IFN.alpha..
[0359] The construction of the mammalian expression vector as well
as the subsequent generation of the production clones and the
purification of C.sub.H3-AD2-IgG-v-mab are disclosed in the
preceding Examples. The expressed recombinant fusion protein has
the AD2 peptide linked to the carboxyl terminus of the C.sub.H3
domain of v-mab via a 15 amino acid long flexible linker peptide.
Co-expression of the heavy chain-AD2 and light chain polypeptides
results in the formation of an IgG structure equipped with two AD2
peptides. The expression vector was transfected into Sp/ESF cells
(an engineered cell line of Sp2/0) by electroporation. The pdHL2
vector contains the gene for dihydrofolate reductase, thus allowing
clonal selection, as well as gene amplification with methotrexate
(MTX). Stable clones were isolated from 96-well plates selected
with media containing 0.2 .mu.M MTX. Clones were screened for
C.sub.H3-AD2-IgG-vmab productivity via a sandwich ELISA. The module
was produced in roller bottle culture with serum-free media.
[0360] The DDD-module, IFN.alpha.2b-DDD2, was generated as
discussed above by recombinant fusion of the DDD2 peptide to the
carboxyl terminus of human IFN.alpha.2b via an 18 amino acid long
flexible linker peptide. As is the case for all DDD-modules, the
expressed fusion protein spontaneously forms a stable
homodimer.
[0361] The C.sub.H1-DDD2-Fab-hL243 expression vector was generated
from hL243-IgG-pdHL2 vector by excising the sequence for the
C.sub.H1-Hinge-C.sub.H2-C.sub.H3 domains with SacII and EagI
restriction enzymes and replacing it with a 507 bp sequence
encoding C.sub.H1-DDD2, which was excised from the
C-DDD2-hMN-14-pdHL2 expression vector with the same enzymes.
Following transfection of C.sub.H1-DDD2-Fab-hL243-pdHL2 into Sp/ESF
cells by electroporation, stable, MTX-resistant clones were
screened for productivity via a sandwich ELISA using 96-well
microtiter plates coated with mouse anti-human kappa chain to
capture the fusion protein, which was detected with horseradish
peroxidase-conjugated goat anti-human Fab. The module was produced
in roller bottle culture.
[0362] Roller bottle cultures in serum-free H-SFM media and
fed-batch bioreactor production resulted in yields comparable to
other IgG-AD2 modules and cytokine-DDD2 modules generated to date.
C.sub.H3-AD2-IgG-v-mab and IFN.alpha.2b-DDD2 were purified from the
culture broths by affinity chromatography using MABSELECT.TM. (GE
Healthcare) and HIS-SELECT.RTM. HF Nickel Affinity Gel (Sigma),
respectively, as described previously (Rossi et al., Blood 2009,
114:3864-71). The culture broth containing the
C.sub.H1-DDD2-Fab-hL243 module was applied directly to
KAPPASELECT.RTM. affinity gel (GE-Healthcare), which was washed to
baseline with PBS and eluted with 0.1 M Glycine, pH 2.5.
[0363] The purity of the DNL modules was assessed by SDS-PAGE and
SE-HPLC (not shown). Analysis under non-reducing conditions showed
that, prior to the DNL reaction, IFN.alpha.2b-DDD2 and
C.sub.H1-DDD2-Fab-hL243 exist as disulfide-linked dimers (not
shown). This phenomenon, which is always seen with DDD-modules, is
beneficial, as it protects the reactive sulfhydryl groups from
irreversible oxidation. In comparison, C.sub.H3-AD2-IgG-v-mab (not
shown) exists as both a monomer and a disulfide-linked dimer, and
is reduced to monomer during the DNL reaction. Reducing SDS-PAGE
demonstrated that each module was purified to near homogeneity and
identified the component polypeptides comprising each module (not
shown).
[0364] Generation of 20-C2-2b by DNL
[0365] Three DNL modules (C.sub.H3-AD2-IgG-v-mab,
C.sub.H1-DDD2-Fab-hL243, and IFN-.alpha.2b-DDD2) were combined in
equimolar quantities to generate the bsMAb-IFN.alpha., 20-C2-2b.
Following an overnight docking step under mild reducing conditions
(1 mM reduced glutathione) at room temperature, oxidized
glutathione was added (2 mM) to facilitate disulfide bond formation
(locking). The 20-C2-2b was purified to near homogeneity using
three sequential affinity chromatography steps, first with Protein
A (MABSELECT.TM.), second by IMAC using HIS-SELECT.RTM. HF Nickel
Affinity Gel, and third by an hL243-anti-idiotype affinity
chromatography. Only those DNL constructs comprising each of the 3
desired monomers bound to all three columns.
[0366] The skilled artisan will realize that affinity
chromatography may be used to purify DNL complexes comprising any
combination of effector moieties, so long as ligands for each of
the three effector moieties can be obtained and attached to the
column material. The selected DNL construct is the one that binds
to each of three columns containing the ligand for each of the
three effector moieties and can be eluted after washing to remove
unbound complexes.
[0367] Generation and Characterization of 20-C2-2b
[0368] The bispecific MAb-IFN.alpha. was generated by combining the
IgG-AD2 module, C.sub.H3-AD2-IgG-v-mab, with two different dimeric
DDD-modules, C.sub.H1-DDD2-Fab-hL243 and IFN.alpha.2b-DDD2. Due to
the random association of either DDD-module with the two AD2
groups, two side-products, 20-C2-C2 and 20-2b-2b are expected to
form, in addition to 20-C2-2b.
[0369] Non-reducing SDS-PAGE (not shown) resolved 20-C2-2b
(.about.305 kDa) as a cluster of bands positioned between those of
20-C2-C2 (.about.365 kDa) and 20-2b-2b (255 kDa). Reducing SDS-PAGE
resolved the five polypeptides (v-mab HC-AD2, hL243 Fd-DDD2,
IFN.alpha.2b-DDD2 and co-migrating v-mab and hL243 kappa light
chains) comprising 20-C2-2b (not shown). IFN.alpha.2b-DDD2 and
hL243 Fd-DDD2 are absent in 20-C2-C2 and 20-2b-2b. MABSELECT.TM.
binds to all three of the major species produced in the DNL
reaction, but removes any excess IFN.alpha.2b-DDD2 and
C.sub.H1-DDD2-Fab-hL243. The HIS-SELECT.RTM. unbound fraction
contained mostly 20-C2-C2 (not shown). The unbound fraction from WT
affinity chromatography comprised 20-2b-2b (not shown). Each of the
samples was subjected to SE-HPLC and immunoreactivity analyses,
which corroborated the results and conclusions of the SDS-PAGE
analysis.
[0370] SE-HPLC analysis of 20-C2-2b resolved a predominant protein
peak with a retention time (6.7 min) consistent with its calculated
mass and between those of the larger 20-C2-C2 (6.6 min) and smaller
20-2b-2b (6.85 min), as well as some higher molecular weight peaks
that likely represent non-covalent dimers formed via
self-association of IFN.alpha.2b (not shown).
[0371] Immunoreactivity assays demonstrated the homogeneity of
20-C2-2b with each molecule containing the three functional groups
(not shown). Incubation of 20-C2-2b with an excess of antibodies to
any of the three constituent modules resulted in quantitative
formation of high molecular weight immune complexes and the
disappearance of the 20-C2-2b peak (not shown). The MAb-IFN.alpha.
showed similar binding avidity to their parental MAbs (not
shown).
[0372] IFN.alpha. Biological Activity
[0373] The specific activities for various MAb-IFN.alpha. were
measured using a cell-based reporter gene assay and compared to
peginterferon alfa-2b (not shown). Expectedly, the specific
activity of 20-C2-2b (2454 IU/pmol), which has two IFN.alpha.2b
groups, was significantly lower than those of 20-2b-2b (4447
IU/pmol) or 734-2b-2b (3764 IU/pmol), yet greater than
peginterferon alfa-2b (P<0.001) (not shown). The difference
between 20-2b-2b and 734-2b-2b was not significant. The specific
activity among all agents varies minimally when normalized to
IU/pmol of total IFN.alpha.. Based on these data, the specific
activity of each IFN.alpha.2b group of the MAb-IFN.alpha. is
approximately 30% of recombinant IFN.alpha.2b (.about.4000
IU/pmol).
[0374] In the ex-vivo setting, the 20-C2-2b DNL construct depleted
lymphoma cells more effectively than normal B cells and had no
effect on T cells (not shown). However, it did efficiently
eliminate monocytes (not shown). Where v-mab had no effect on
monocytes, depletion was observed following treatment with
hL243.alpha.4p and MAb-IFN.alpha., with 20-2b-2b and 734-2b-2b
exhibiting similar toxicity (not shown). Therefore, the predictably
higher potency of 20-C2-2b is attributed to the combined actions of
anti-HLA-DR and IFN.alpha., which may be augmented by HLA-DR
targeting.
[0375] The skilled artisan will realize that the approach described
here to produce and use bispecific immunocytokine, or other DNL
constructs comprising three different effector moieties, may be
utilized with any combinations of antibodies, antibody fragments,
cytokines or other effectors that may be incorporated into a DNL
construct, for example the combination of anti-CD20 and anti-CD22
with IFN.alpha.2b.
Example 24. Hexavalent DNL Constructs
[0376] The DNL technology described above for formation of
trivalent DNL complexes was applied to generate hexavalent
IgG-based DNL structures (HIDS). Because of the increased number of
binding sites for target antigens, hexavalent constructs are
expected to show greater affinity and/or efficacy against target
cells. Two types of modules, which were produced as recombinant
fusion proteins, were combined to generate a variety of HIDS.
Fab-DDD2 modules were as described above. The Fab-DDD2 modules form
stable homodimers that bind to AD2-containing modules. To generate
HIDS, C--H-AD2-IgG modules were created to pair with the Fab-DDD2
modules.
[0377] C--H-AD2-IgG modules have an AD2 peptide fused to the
carboxyl terminus (C) of the heavy (HI) chain of IgG via a peptide
linker. The DNA coding sequences for the linker peptide followed by
the AD2 peptide are coupled to the 3' end of the CH3 (heavy chain
constant domain 3) coding sequence by standard recombinant DNA
methodologies, resulting in a contiguous open reading frame. When
the heavy chain-AD2 polypeptide is co-expressed with a light chain
polypeptide, an IgG molecule is formed possessing two AD2 peptides,
which can therefore bind two Fab-DDD2 dimers. The C--H-AD2-IgG
module can be combined with any Fab-DDD2 module to generate a wide
variety of hexavalent structures composed of an Fe fragment and six
Fab fragments. If the C--H-AD2-IgG module and the Fab-DDD2 module
are derived from the same parental monoclonal antibody (MAb) the
resulting HIDS is monospecific with 6 binding arms to the same
antigen. If the modules are instead derived from two different MAbs
then the resulting HIDS are bispecific, with two binding arms for
the specificity of the C--H-AD2-IgG module and 4 binding arms for
the specificity of the Fab-DDD2 module.
[0378] The same technique has been utilized to produce DNL
complexes comprising an IgG moiety attached to four effector
moieties, such as cytokines. In an exemplary embodiment, an IgG
moiety was attached to four copies of interferon-a2b. The
antibody-cytokine DNL construct exhibited superior pharmacokinetic
properties and/or efficacy compared to PEGylated forms of
interferon-.alpha.2b.
[0379] Creation of C--H-AD2-1G-pdHL2 Expression Vectors
[0380] The pdHL2 mammalian expression vector has been used to
mediate the expression of many recombinant IgGs. A plasmid shuttle
vector was produced to facilitate the conversion of any IgG-pdHL2
vector into a C--H-AD2-IgG-pdHL2 vector. The gene for the Fc (CH2
and CH3 domains) was amplified using the pdHL2 vector as a template
and a pair of primers. The amplimer was cloned in the PGEMT.RTM.
PCR cloning vector. The Fe insert fragment was excised from
PGEMT.RTM. with XbaI and BamHI restriction enzymes and ligated with
AD2-pdHL2 vector that was prepared by digestion of
h679-Fab-AD2-pdHL2 with XbaI and BamHI, to generate the shuttle
vector Fc-AD2-pdHL2.
[0381] To convert any IgG-pdHL2 expression vector to a
C--H-AD2-IgG-pdHL2 expression vector, an 861 bp BsrGI/NdeI
restriction fragment is excised from the former and replaced with a
952 bp BsrGI/NdeI restriction fragment excised from the
Fc-AD2-pdHL2 vector. BsrG1 cuts in the CH3 domain and NdeI cuts
downstream (3') of the expression cassette.
[0382] Production of C--H-AD2-hLL2 IgG
[0383] Epratuzumab, or hLL2 IgG, is a humanized anti-human CD22
MAb. An expression vector for C--H-AD2-hLL2 IgG was generated from
hLL2 IgG-pdHL2, as described above, and used to transfect Sp2/0
myeloma cells by electroporation. Following transfection, the cells
were plated in 96-well plates and transgenic clones were selected
in media containing methotrexate. Clones were screened for
C--H-AD2-hLL2 IgG productivity by a sandwich ELISA using 96-well
microtiter plates coated with an hLL2-specific anti-idiotype MAb
and detection with peroxidase-conjugated anti-human IgG. Clones
were expanded to roller bottles for protein production and
C--H-AD2-hLL2 IgG was purified from the spent culture media in a
single step using Protein-A affinity chromatography. SDS-PAGE
analysis demonstrated that the purified C--H-AD2-hLL2-IgG consisted
of both monomeric and disulfide-linked dimeric forms of the module
(not shown). Protein bands representing these two forms are evident
by SDS-PAGE under non-reducing conditions, while under reducing
conditions all of the forms are reduced to two bands representing
the constituent polypeptides (Heavy chain-AD2 and kappa chain) (not
shown). No other contaminating bands were detected.
[0384] Production of C--H-AD2-hA20 IgG
[0385] hA20 IgG is a humanized anti-human CD20 MAb. An expression
vector for C--H-AD2-hA20 IgG was generated from hA20 IgG-pDHL2, as
described above, and used to transfect Sp2/0 myeloma cells by
electroporation. Following transfection, the cells were plated in
96-well plates and transgenic clones were selected in media
containing methotrexate. Clones were screened for C--H-AD2-hA20 IgG
productivity by a sandwich ELISA using 96-well microtiter plates
coated with a hA20-specific anti-idiotype MAb and detection with
peroxidase-conjugated anti-human IgG. Clones were expanded to
roller bottles for protein production and C--H-AD2-hA20 IgG was
purified from the spent culture media in a single step using
Protein-A affinity chromatography. SE-HPLC and SDS-PAGE analyses
gave very similar results to those obtained for C--H-AD2-hLL2 IgG
(not shown).
Example 25. Generation of Hexavalent DNL Constructs
[0386] Generation of Hex-hA20
[0387] The DNL method was used to create Hex-hA20, a monospecific
anti-CD20 HIDS, by combining C--H-AD2-hA20 IgG with hA20-Fab-DDD2.
The Hex-hA20 structure contains six anti-CD20 Fab fragments and an
Fc fragment, arranged as four Fab fragments and one IgG antibody.
Hex-hA20 was made as described below.
[0388] A 210% molar equivalent of (hA20-Fab-DDD2).sub.2 was mixed
with C--H-AD2-hA20 IgG. This molar ratio was used because two
Fab-DDD2 dimers are coupled to each C--H-AD2-hA20 IgG molecule and
an additional 10% excess of the former to ensure that the coupling
reaction is complete. The mixture was typically made in phosphate
buffered saline, pH 7.4 (PBS) with 1 mM EDTA. Then reduced
glutathione (GSH) was added to a final concentration of 1 mM and
the solution was held at room temperature (16-25.degree. C.) for
1-24 hours. Following reduction, oxidized glutathione (GSSH) was
added directly to the reaction mixture to a final concentration of
2 mM and the solution was held at room temperature for 1-24
hours.
[0389] After oxidation, the reaction mixture was loaded directly
onto a Protein-A affinity chromatography column. The column was
washed with PBS and the Hex-hA20 was eluted with 0.1 M glycine, pH
2.5. Since excess hA20-Fab-DDD2 was used in the reaction, there was
no unconjugated C--H-AD2-hA20 IgG, or incomplete DNL structures
containing only one (hA20-Fab-DDD2).sub.2 moiety. The unconjugated
excess hA20-Fab-DDD2 does not bind to the affinity resin. The
calculated molecular weight from the deduced amino acid sequences
of the constituent polypeptides is 386 kDa. Size exclusion HPLC
analysis showed a single protein peak with a retention time
consistent with a protein structure of 375-400 kDa (not shown).
[0390] Generation of Hex-hLL2
[0391] The DNL method was used to create a monospecific anti-CD22
HIDS (Hex-hLL2) by combining C--H-AD2-hLL2 IgG with hLL2-Fab-DDD2.
The DNL reaction was accomplished as described above for Hex-hA20.
The calculated molecular weight from the deduced amino acid
sequences of the constituent polypeptides is 386 kDa. Size
exclusion HPLC analysis showed a single protein peak with a
retention time consistent with a protein structure of 375-400 kDa
(not shown). SDS-PAGE analysis under non-reducing conditions showed
a cluster of high molecular weight bands, which were eliminated
under reducing conditions to leave only the three expected
polypeptide chains: HC-AD2, Fd-DDD2, and the kappa chain (not
shown).
[0392] Generation of DNL1 and DNL1C
[0393] The DNL method was used to create bispecific HIDS by
combining C--H-AD2-hLL2 IgG with either hA20-Fab-DDD2 to obtain
DNL1 or hMN-14-DDD2 to obtain DNL1C. DNL1 has four binding arms for
CD20 and two for CD22. As hMN-14 is a humanized MAb to
carcinoembryonic antigen (CEACAM5), DNL1C has four binding arms for
CEACAM5 and two for CD22. The DNL reactions were accomplished as
described for Hex-hA20 above. HPLC and SDS-PAGE were consistent
with the desired products.
[0394] Generation of DNL2 and DNL2C
[0395] The DNL method was used to create bispecific HIDS by
combining C--H-AD2-hA20 IgG with either hLL2-Fab-DDD2 to obtain
DNL2 or hMN-14-DDD2 to obtain DNL2C. DNL2 has four binding arms for
CD22 and two for CD20. DNL2C has four binding arms for CEACAM5 and
two for CD20. The DNL reactions were accomplished as described for
Hex-hA20. HPLC and SDS-PAGE were consistent with the desired
products.
[0396] Stability in Serum
[0397] The stability of DNL1 and DNL2 in human serum was determined
using a bispecific ELISA assay. The protein structures were
incubated at 10 .mu.g/ml in fresh pooled human sera at 37.degree.
C. and 5% CO.sub.2 for five days. For day 0 samples, aliquots were
frozen in liquid nitrogen immediately after dilution in serum.
ELISA plates were coated with an anti-Id to hA20 IgG and bispecific
binding was detected with an anti-Id to hLL2 IgG. Both DNL1 and
DNL2 were highly stable in serum and maintained complete bispecific
binding activity (not shown).
[0398] Binding Activity
[0399] The HIDS generated as described above retained the binding
properties of their parental Fab/IgGs. Competitive ELISAs were used
to investigate the binding avidities of the various HIDS using
either a rat anti-idiotype MAb to hA20 (WR2) to assess the binding
activity of the hA20 components or a rat anti-idiotype MAb to hLL2
(WN) to assess the binding activity of the hLL2 components. To
assess hA20 binding, ELISA plates were coated with hA20 IgG and the
HIDS were allowed to compete with the immobilized IgG for WR2
binding. To assess hLL2 binding, plates were coated with hLL2 IgG
and the HIDS were allowed to compete with the immobilized IgG for
WN binding. The relative amount of anti-Id bound to the immobilized
IgG was detected using peroxidase-conjugated anti-Rat IgG.
[0400] Examining the relative CD20 binding avidities, DNL2, which
has two CD20 binding groups, showed a similar binding avidity to
hA20 IgG, which also has two CD20-binding arms (not shown). DNL1,
which has four CD20-binding groups, had a stronger (.about.4-fold)
relative avidity than DNL2 or hA20 IgG (not shown). Hex-hA20, which
has six CD20-binding groups, had an even stronger (.about.10-fold)
relative avidity than hA20 IgG (not shown).
[0401] Similar results were observed for CD22 binding. DNL1, which
has two CD20 binding groups, showed a similar binding avidity to
hLL2 IgG, which also has two CD22-binding arms (not shown). DNL2,
which has four CD22-binding groups, had a stronger (>5-fold)
relative avidity than DNL1 or hLL2 IgG. Hex-hLL2, which has six
CD22-binding groups, had an even stronger (>10-fold) relative
avidity than hLL2 IgG (not shown). As both DNL2 and DNL3 contain
two hA20 Fabs and four hLL2 Fabs, they showed similar strength in
binding to the same anti-id antibody (not shown).
[0402] In Vivo Anti-Tumor Activity
[0403] The HIDS were shown to have therapeutic efficacy in vive
using a human Burkitt Lymphoma model in mice. Low doses (12 .mu.g)
of DNL2 and Hex-hA20 more than doubled the survival times of tumor
bearing mice. Treatment with higher doses (60 .mu.g) resulted in
long-term survivors.
[0404] In Vitro Activity
[0405] Some of the HIDS were observed to have potent
anti-proliferative activity on lymphoma cell lines. DNL1, DNL2 and
Hex-hA20 inhibited cell growth of Daudi Burkitt Lymphoma cells in
vitro (not shown). Treatment of the cells with 10 nM concentrations
was substantially more effective for the HIDS compared to rituximab
(not shown). Using a cell counting assay, the potency of DNL1 and
DNL2 was estimated to be more than 100-fold greater than that of
rituximab, while the Hex-hA20 was shown to be even more potent (not
shown). This was confirmed with an MTS proliferation assay in which
dose-response curves were generated for Daudi cells treated with a
range of concentrations of the HIDS (not shown). Compared to
rituximab, the bispecific HIDS (DNL1 and DNL2) and Hex-hA20 were
>100-fold and >10000-fold more potent, respectively.
[0406] Dose-response curves for HIDS (DNL1, DNL2, Hex-hA20) versus
a parent IgG (hA20 IgG) were compared for three different lymphoma
cell lines, using an MTS proliferation assay. In Daudi lymphoma
cells, the bispecific structures DNL1 and DNL2 showed >100-fold
more potent anti-proliferative activity and Hex-hA20 showed
>10,000-fold more potent activity than the parent hA20 IgG (not
shown). Hex-hLL2 and the control structures (DNL1-C and DNL2-C) had
very little anti-proliferative activity in this assay (not
shown).
[0407] In Raji lymphoma cells, Hex-hA20 displayed potent
anti-proliferative activity, but DNL2 showed only minimal activity
compared with hA20 IgG (not shown). In Ramos lymphoma cells, both
DNL2 and Hex-hA20 displayed potent anti-proliferative activity,
compared with hA20 IgG (not shown). These results show that the
increased potency of HIDS relative to the parent IgGs is not
limited to particular cell lines, but rather is a general
phenomenon for cells displaying the appropriate targets.
[0408] CDC and ADCC Activity of Hexavalent DNL Constructs
[0409] In vivo, anti-CD20 monoclonal antibodies such as rituximab
and hA20 can utilize complement-dependent cytotoxicity (CDC),
antibody-dependent cellular cytotoxicity (ADCC) and signal
transduction induced growth inhibition/apoptosis for tumor cell
killing. The hexavalent DNL structures (DNL1, DNL2, Hex-hA20) were
tested for CDC activity using Daudi cells in an in vitro assay.
Surprisingly, none of the hexavalent structures that bind CD20
exhibited CDC activity (not shown). The parent hA20 IgG exhibited
potent CDC activity (not shown), while as expected the hLL2
antibody against CD22 showed no activity (not shown). The lack of
effect of DNL2 and Hex-hA20 was of interest, since they comprise
hA20-IgG-Ad2, which showed similar positive CDC activity to hA20
IgG (not shown).
[0410] DNL1 was assayed for ADCC activity using freshly isolated
peripheral blood mononuclear cells. Both rituximab and hA20 IgG
showed potent activity on Daudi cells, while DNL1 did not exhibit
any detectable ADCC activity (not shown).
[0411] These data suggest that the Fc region may become
inaccessible for effector functions (CDC and ADCC) when four
additional Fab groups are tethered to its carboxyl termini.
Therefore, the hexavalent DNL structures appear to rely only on
signal transduction induced growth inhibition/apoptosis for in vivo
anti-tumor activity.
[0412] It will be readily apparent to one skilled in the art that
varying substitutions and modifications may be made to the
invention disclosed herein without departing from the scope and
spirit of the invention. Thus, such additional embodiments are
within the scope of the present invention.
Sequence CWU 1
1
140116PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 1Lys Ser Ser Gln Ser Val Leu Tyr Ser Ala Asn His
Lys Tyr Leu Ala 1 5 10 15 27PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 2Trp Ala Ser Thr Arg Glu Ser
1 5 39PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 3His Gln Tyr Leu Ser Ser Trp Thr Phe 1 5
45PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 4Ser Tyr Trp Leu His 1 5 517PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 5Tyr
Ile Asn Pro Arg Asn Asp Tyr Thr Glu Tyr Asn Gln Asn Phe Lys 1 5 10
15 Asp 67PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 6Arg Asp Ile Thr Thr Phe Tyr 1 5 710PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 7Arg
Ala Ser Ser Ser Val Ser Tyr Ile His 1 5 10 87PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 8Ala
Thr Ser Asn Leu Ala Ser 1 5 99PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 9Gln Gln Trp Thr Ser Asn Pro
Pro Thr 1 5 105PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 10Ser Tyr Asn Met His 1 5
1117PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 11Ala Ile Tyr Pro Gly Asn Gly Asp Thr Ser Tyr Asn
Gln Lys Phe Lys 1 5 10 15 Gly 1212PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 12Ser Thr Tyr Tyr Gly Gly
Asp Trp Tyr Phe Asp Val 1 5 10 134PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 13Ala Leu Ala Leu 1
14330PRTHomo sapiens 14Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu
Ala Pro Ser Ser Lys 1 5 10 15 Ser Thr Ser Gly Gly Thr Ala Ala Leu
Gly Cys Leu Val Lys Asp Tyr 20 25 30 Phe Pro Glu Pro Val Thr Val
Ser Trp Asn Ser Gly Ala Leu Thr Ser 35 40 45 Gly Val His Thr Phe
Pro Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser 50 55 60 Leu Ser Ser
Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr Gln Thr 65 70 75 80 Tyr
Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val Asp Lys 85 90
95 Arg Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro Pro Cys
100 105 110 Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe
Pro Pro 115 120 125 Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro
Glu Val Thr Cys 130 135 140 Val Val Val Asp Val Ser His Glu Asp Pro
Glu Val Lys Phe Asn Trp 145 150 155 160 Tyr Val Asp Gly Val Glu Val
His Asn Ala Lys Thr Lys Pro Arg Glu 165 170 175 Glu Gln Tyr Asn Ser
Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu 180 185 190 His Gln Asp
Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn 195 200 205 Lys
Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly 210 215
220 Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Glu Glu
225 230 235 240 Met Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys
Gly Phe Tyr 245 250 255 Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn
Gly Gln Pro Glu Asn 260 265 270 Asn Tyr Lys Thr Thr Pro Pro Val Leu
Asp Ser Asp Gly Ser Phe Phe 275 280 285 Leu Tyr Ser Lys Leu Thr Val
Asp Lys Ser Arg Trp Gln Gln Gly Asn 290 295 300 Val Phe Ser Cys Ser
Val Met His Glu Ala Leu His Asn His Tyr Thr 305 310 315 320 Gln Lys
Ser Leu Ser Leu Ser Pro Gly Lys 325 330 1544PRTHomo sapiens 15Ser
His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10
15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala
20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
1645PRTHomo sapiens 16Cys Gly His Ile Gln Ile Pro Pro Gly Leu Thr
Glu Leu Leu Gln Gly 1 5 10 15 Tyr Thr Val Glu Val Leu Arg Gln Gln
Pro Pro Asp Leu Val Glu Phe 20 25 30 Ala Val Glu Tyr Phe Thr Arg
Leu Arg Glu Ala Arg Ala 35 40 45 1717PRTHomo sapiens 17Gln Ile Glu
Tyr Leu Ala Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala
1821PRTHomo sapiens 18Cys Gly Gln Ile Glu Tyr Leu Ala Lys Gln Ile
Val Asp Asn Ala Ile 1 5 10 15 Gln Gln Ala Gly Cys 20 1950PRTHomo
sapiens 19Ser Leu Arg Glu Cys Glu Leu Tyr Val Gln Lys His Asn Ile
Gln Ala 1 5 10 15 Leu Leu Lys Asp Ser Ile Val Gln Leu Cys Thr Ala
Arg Pro Glu Arg 20 25 30 Pro Met Ala Phe Leu Arg Glu Tyr Phe Glu
Arg Leu Glu Lys Glu Glu 35 40 45 Ala Lys 50 2055PRTHomo sapiens
20Met Ser Cys Gly Gly Ser Leu Arg Glu Cys Glu Leu Tyr Val Gln Lys 1
5 10 15 His Asn Ile Gln Ala Leu Leu Lys Asp Ser Ile Val Gln Leu Cys
Thr 20 25 30 Ala Arg Pro Glu Arg Pro Met Ala Phe Leu Arg Glu Tyr
Phe Glu Arg 35 40 45 Leu Glu Lys Glu Glu Ala Lys 50 55 2123PRTHomo
sapiens 21Cys Gly Phe Glu Glu Leu Ala Trp Lys Ile Ala Lys Met Ile
Trp Ser 1 5 10 15 Asp Val Phe Gln Gln Gly Cys 20 2251PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
22Ser Leu Arg Glu Cys Glu Leu Tyr Val Gln Lys His Asn Ile Gln Ala 1
5 10 15 Leu Leu Lys Asp Val Ser Ile Val Gln Leu Cys Thr Ala Arg Pro
Glu 20 25 30 Arg Pro Met Ala Phe Leu Arg Glu Tyr Phe Glu Lys Leu
Glu Lys Glu 35 40 45 Glu Ala Lys 50 2354PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
23Ser Leu Lys Gly Cys Glu Leu Tyr Val Gln Leu His Gly Ile Gln Gln 1
5 10 15 Val Leu Lys Asp Cys Ile Val His Leu Cys Ile Ser Lys Pro Glu
Arg 20 25 30 Pro Met Lys Phe Leu Arg Glu His Phe Glu Lys Leu Glu
Lys Glu Glu 35 40 45 Asn Arg Gln Ile Leu Ala 50 2444PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
24Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Gly Gln Gln Pro Pro Asp Leu Val Asp Phe Ala
Val 20 25 30 Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Arg Gln 35 40
2544PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 25Ser Ile Glu Ile Pro Ala Gly Leu Thr Glu Leu
Leu Gln Gly Phe Thr 1 5 10 15 Val Glu Val Leu Arg His Gln Pro Ala
Asp Leu Leu Glu Phe Ala Leu 20 25 30 Gln His Phe Thr Arg Leu Gln
Gln Glu Asn Glu Arg 35 40 2644PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 26Thr His Ile Gln Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 2744PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
27Ser Lys Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
2844PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 28Ser Arg Ile Gln Ile Pro Pro Gly Leu Thr Glu
Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro
Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 2944PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 29Ser His Ile Asn Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 3044PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
30Ser His Ile Gln Ile Pro Pro Ala Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
3144PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 31Ser His Ile Gln Ile Pro Pro Gly Leu Ser Glu
Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro
Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 3244PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 32Ser His Ile Gln Ile Pro
Pro Gly Leu Thr Asp Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 3344PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
33Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Asn Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
3444PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 34Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu
Leu Leu Gln Ala Tyr 1 5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro
Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 3544PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 35Ser His Ile Gln Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Ser Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 3644PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
36Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Asp Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
3744PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 37Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu
Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val Leu Lys Gln Gln Pro
Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 3844PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 38Ser His Ile Gln Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Asn Gln Pro Pro Asp Leu Val Glu Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 3944PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
39Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Asn Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
4044PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 40Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu
Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro
Pro Glu Leu Val Glu Phe Ala 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 4144PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 41Ser His Ile Gln Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Asp Phe Ala 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 4244PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
42Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Leu 20 25 30 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
4344PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 43Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu
Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro
Pro Asp Leu Val Glu Phe Ile 20 25 30 Val Glu Tyr Phe Thr Arg Leu
Arg Glu Ala Arg Ala 35 40 4444PRTArtificial SequenceDescription of
Artificial Sequence Synthetic polypeptide 44Ser His Ile Gln Ile Pro
Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1 5 10 15 Thr Val Glu Val
Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Val 20 25 30 Val Glu
Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40 4544PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
45Ser His Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 1
5 10 15 Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe
Ala 20 25 30 Val Asp Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala 35 40
4617PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 46Asn Ile Glu Tyr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 4717PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 47Gln Leu Glu Tyr Leu Ala
Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala
4817PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 48Gln Val Glu Tyr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 4917PRTArtificial SequenceDescription
of Artificial
Sequence Synthetic peptide 49Gln Ile Asp Tyr Leu Ala Lys Gln Ile
Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala 5017PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 50Gln
Ile Glu Phe Leu Ala Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10
15 Ala 5117PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 51Gln Ile Glu Thr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 5217PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 52Gln Ile Glu Ser Leu Ala
Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala
5317PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 53Gln Ile Glu Tyr Ile Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 5417PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 54Gln Ile Glu Tyr Val Ala
Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala
5517PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 55Gln Ile Glu Tyr Leu Ala Arg Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 5617PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 56Gln Ile Glu Tyr Leu Ala
Lys Asn Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ala
5717PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 57Gln Ile Glu Tyr Leu Ala Lys Gln Ile Val Glu Asn
Ala Ile Gln Gln 1 5 10 15 Ala 5817PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 58Gln Ile Glu Tyr Leu Ala
Lys Gln Ile Val Asp Gln Ala Ile Gln Gln 1 5 10 15 Ala
5917PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 59Gln Ile Glu Tyr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Asn Gln 1 5 10 15 Ala 6017PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 60Gln Ile Glu Tyr Leu Ala
Lys Gln Ile Val Asp Asn Ala Ile Gln Asn 1 5 10 15 Ala
6117PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 61Gln Ile Glu Tyr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Leu 6217PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 62Gln Ile Glu Tyr Leu Ala
Lys Gln Ile Val Asp Asn Ala Ile Gln Gln 1 5 10 15 Ile
6317PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 63Gln Ile Glu Tyr Leu Ala Lys Gln Ile Val Asp Asn
Ala Ile Gln Gln 1 5 10 15 Val 6417PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 64Gln Ile Glu Tyr Val Ala
Lys Gln Ile Val Asp Tyr Ala Ile His Gln 1 5 10 15 Ala
6517PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 65Gln Ile Glu Tyr Lys Ala Lys Gln Ile Val Asp His
Ala Ile His Gln 1 5 10 15 Ala 6617PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 66Gln Ile Glu Tyr His Ala
Lys Gln Ile Val Asp His Ala Ile His Gln 1 5 10 15 Ala
6717PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 67Gln Ile Glu Tyr Val Ala Lys Gln Ile Val Asp His
Ala Ile His Gln 1 5 10 15 Ala 6818PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 68Pro Leu Glu Tyr Gln Ala
Gly Leu Leu Val Gln Asn Ala Ile Gln Gln 1 5 10 15 Ala Ile
6918PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 69Leu Leu Ile Glu Thr Ala Ser Ser Leu Val Lys Asn
Ala Ile Gln Leu 1 5 10 15 Ser Ile 7018PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 70Leu
Ile Glu Glu Ala Ala Ser Arg Ile Val Asp Ala Val Ile Glu Gln 1 5 10
15 Val Lys 7118PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 71Ala Leu Tyr Gln Phe Ala Asp Arg Phe
Ser Glu Leu Val Ile Ser Glu 1 5 10 15 Ala Leu 7217PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 72Leu
Glu Gln Val Ala Asn Gln Leu Ala Asp Gln Ile Ile Lys Glu Ala 1 5 10
15 Thr 7317PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 73Phe Glu Glu Leu Ala Trp Lys Ile Ala Lys Met Ile
Trp Ser Asp Val 1 5 10 15 Phe 7418PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 74Glu Leu Val Arg Leu Ser
Lys Arg Leu Val Glu Asn Ala Val Leu Lys 1 5 10 15 Ala Val
7518PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 75Thr Ala Glu Glu Val Ser Ala Arg Ile Val Gln Val
Val Thr Ala Glu 1 5 10 15 Ala Val 7618PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 76Gln
Ile Lys Gln Ala Ala Phe Gln Leu Ile Ser Gln Val Ile Leu Glu 1 5 10
15 Ala Thr 7716PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 77Leu Ala Trp Lys Ile Ala Lys Met Ile
Val Ser Asp Val Met Gln Gln 1 5 10 15 7824PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 78Asp
Leu Ile Glu Glu Ala Ala Ser Arg Ile Val Asp Ala Val Ile Glu 1 5 10
15 Gln Val Lys Ala Ala Gly Ala Tyr 20 7918PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 79Leu
Glu Gln Tyr Ala Asn Gln Leu Ala Asp Gln Ile Ile Lys Glu Ala 1 5 10
15 Thr Glu 8020PRTArtificial SequenceDescription of Artificial
Sequence Synthetic peptide 80Phe Glu Glu Leu Ala Trp Lys Ile Ala
Lys Met Ile Trp Ser Asp Val 1 5 10 15 Phe Gln Gln Cys 20
8117PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 81Gln Ile Glu Tyr Leu Ala Lys Gln Ile Pro Asp Asn
Ala Ile Gln Gln 1 5 10 15 Ala 8225PRTArtificial SequenceDescription
of Artificial Sequence Synthetic peptide 82Lys Gly Ala Asp Leu Ile
Glu Glu Ala Ala Ser Arg Ile Val Asp Ala 1 5 10 15 Val Ile Glu Gln
Val Lys Ala Ala Gly 20 25 8325PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 83Lys Gly Ala Asp Leu Ile Glu
Glu Ala Ala Ser Arg Ile Pro Asp Ala 1 5 10 15 Pro Ile Glu Gln Val
Lys Ala Ala Gly 20 25 8425PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 84Pro Glu Asp Ala Glu Leu Val
Arg Leu Ser Lys Arg Leu Val Glu Asn 1 5 10 15 Ala Val Leu Lys Ala
Val Gln Gln Tyr 20 25 8525PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 85Pro Glu Asp Ala Glu Leu Val
Arg Thr Ser Lys Arg Leu Val Glu Asn 1 5 10 15 Ala Val Leu Lys Ala
Val Gln Gln Tyr 20 25 8625PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 86Pro Glu Asp Ala Glu Leu Val
Arg Leu Ser Lys Arg Asp Val Glu Asn 1 5 10 15 Ala Val Leu Lys Ala
Val Gln Gln Tyr 20 25 8725PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 87Pro Glu Asp Ala Glu Leu Val
Arg Leu Ser Lys Arg Leu Pro Glu Asn 1 5 10 15 Ala Val Leu Lys Ala
Val Gln Gln Tyr 20 25 8825PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 88Pro Glu Asp Ala Glu Leu Val
Arg Leu Ser Lys Arg Leu Pro Glu Asn 1 5 10 15 Ala Pro Leu Lys Ala
Val Gln Gln Tyr 20 25 8925PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 89Pro Glu Asp Ala Glu Leu Val
Arg Leu Ser Lys Arg Leu Val Glu Asn 1 5 10 15 Ala Val Glu Lys Ala
Val Gln Gln Tyr 20 25 9025PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 90Glu Glu Gly Leu Asp Arg Asn
Glu Glu Ile Lys Arg Ala Ala Phe Gln 1 5 10 15 Ile Ile Ser Gln Val
Ile Ser Glu Ala 20 25 9125PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 91Leu Val Asp Asp Pro Leu Glu
Tyr Gln Ala Gly Leu Leu Val Gln Asn 1 5 10 15 Ala Ile Gln Gln Ala
Ile Ala Glu Gln 20 25 9225PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 92Gln Tyr Glu Thr Leu Leu Ile
Glu Thr Ala Ser Ser Leu Val Lys Asn 1 5 10 15 Ala Ile Gln Leu Ser
Ile Glu Gln Leu 20 25 9325PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 93Leu Glu Lys Gln Tyr Gln Glu
Gln Leu Glu Glu Glu Val Ala Lys Val 1 5 10 15 Ile Val Ser Met Ser
Ile Ala Phe Ala 20 25 9425PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 94Asn Thr Asp Glu Ala Gln Glu
Glu Leu Ala Trp Lys Ile Ala Lys Met 1 5 10 15 Ile Val Ser Asp Ile
Met Gln Gln Ala 20 25 9525PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 95Val Asn Leu Asp Lys Lys Ala
Val Leu Ala Glu Lys Ile Val Ala Glu 1 5 10 15 Ala Ile Glu Lys Ala
Glu Arg Glu Leu 20 25 9625PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 96Asn Gly Ile Leu Glu Leu Glu
Thr Lys Ser Ser Lys Leu Val Gln Asn 1 5 10 15 Ile Ile Gln Thr Ala
Val Asp Gln Phe 20 25 9725PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 97Thr Gln Asp Lys Asn Tyr Glu
Asp Glu Leu Thr Gln Val Ala Leu Ala 1 5 10 15 Leu Val Glu Asp Val
Ile Asn Tyr Ala 20 25 9825PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 98Glu Thr Ser Ala Lys Asp Asn
Ile Asn Ile Glu Glu Ala Ala Arg Phe 1 5 10 15 Leu Val Glu Lys Ile
Leu Val Asn His 20 25 9921DNAArtificial SequenceDescription of
Artificial Sequence Synthetic oligonucleotide 99aatgcggcgg
tggtgacagt a 2110021DNAArtificial SequenceDescription of Artificial
Sequence Synthetic oligonucleotide 100aagctcagca cacagaaaga c
2110121DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 101uaaaaucuuc cugcccacct t
2110221DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 102ggaagcuguu ggcugaaaat t
2110321RNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 103aagaccagcc ucuuugccca g
2110419RNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 104ggaccaggca gaaaacgag
1910517RNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 105cuaucaggau gacgcgg
1710621RNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 106ugacacaggc aggcuugacu u
2110719DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 107ggtgaagaag ggcgtccaa
1910860DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 108gatccgttgg agctgttggc gtagttcaag
agactcgcca acagctccaa cttttggaaa 6010920DNAArtificial
SequenceDescription of Artificial Sequence Synthetic
oligonucleotide 109aggtggtgtt aacagcagag 2011021DNAArtificial
SequenceDescription of Artificial Sequence Synthetic
oligonucleotide 110aaggtggagc aagcggtgga g 2111121DNAArtificial
SequenceDescription of Artificial Sequence Synthetic
oligonucleotide 111aaggagttga aggccgacaa a 2111221DNAArtificial
SequenceDescription of Artificial Sequence Synthetic
oligonucleotide 112uauggagcug cagaggaugt t 2111349DNAArtificial
SequenceDescription of Artificial Sequence Synthetic
oligonucleotide 113tttgaatatc tgtgctgaga acacagttct cagcacagat
attcttttt 4911429DNAArtificial SequenceDescription of Artificial
Sequence Synthetic oligonucleotide 114aatgagaaaa gcaaaaggtg
ccctgtctc 2911521RNAArtificial SequenceDescription of Artificial
Sequence Synthetic oligonucleotide 115aaucaucauc aagaaagggc a
2111621DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 116augacuguca ggauguugct t
2111721RNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 117gaacgaaucc ugaagacauc u
2111829DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 118aagcctggct acagcaatat gcctgtctc
2911921DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 119ugaccaucac cgaguuuaut t
2112021DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 120aagtcggacg caacagagaa a
2112121DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 121cuaccuuucu acggacgugt t
2112221DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 122ctgcctaagg cggatttgaa t
2112321DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 123ttauuccuuc uucgggaagu c
2112421DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 124aaccttctgg aacccgccca c
2112519DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 125gagcatcttc gagcaagaa
1912619DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 126catgtggcac cgtttgcct
1912721DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 127aactaccaga aaggtatacc t
2112821DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 128ucacaguguc cuuuauguat t
2112921DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 129gcaugaaccg gaggcccaut t
2113019DNAArtificial SequenceDescription of Artificial Sequence
Synthetic oligonucleotide 130ccggacagtt ccatgtata
1913144PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 131Xaa Xaa Ile Xaa Ile Pro Pro Xaa Leu Xaa
Xaa Leu Leu Xaa Xaa Tyr 1 5 10 15 Xaa Val Xaa Val Leu Xaa Xaa Xaa
Pro Pro Xaa Leu Val Xaa Phe Xaa
20 25 30 Val Xaa Tyr Phe Xaa Xaa Leu Xaa Xaa Xaa Xaa Xaa 35 40
13217PRTArtificial SequenceDescription of Artificial Sequence
Synthetic peptide 132Xaa Xaa Xaa Xaa Xaa Ala Xaa Xaa Ile Val Xaa
Xaa Ala Ile Xaa Xaa 1 5 10 15 Xaa 13344PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
133Xaa His Ile Xaa Ile Pro Pro Gly Leu Xaa Glu Leu Leu Gln Gly Tyr
1 5 10 15 Thr Xaa Glu Val Leu Arg Xaa Gln Pro Pro Asp Leu Val Glu
Phe Ala 20 25 30 Xaa Xaa Tyr Phe Xaa Xaa Leu Xaa Glu Xaa Arg Xaa 35
40 134990DNAHomo sapiens 134gcctccacca agggcccatc ggtcttcccc
ctggcaccct cctccaagag cacctctggg 60ggcacagcgg ccctgggctg cctggtcaag
gactacttcc ccgaaccggt gacggtgtcg 120tggaactcag gcgccctgac
cagcggcgtg cacaccttcc cggctgtcct acagtcctca 180ggactctact
ccctcagcag cgtggtgacc gtgccctcca gcagcttggg cacccagacc
240tacatctgca acgtgaatca caagcccagc aacaccaagg tggacaagag
agttgagccc 300aaatcttgtg acaaaactca cacatgccca ccgtgcccag
cacctgaact cctgggggga 360ccgtcagtct tcctcttccc cccaaaaccc
aaggacaccc tcatgatctc ccggacccct 420gaggtcacat gcgtggtggt
ggacgtgagc cacgaagacc ctgaggtcaa gttcaactgg 480tacgtggacg
gcgtggaggt gcataatgcc aagacaaagc cgcgggagga gcagtacaac
540agcacgtacc gggtggtcag cgtcctcacc gtcctgcacc aggactggct
gaatggcaag 600gagtacaagt gcaaggtctc caacaaagcc ctcccagccc
ccatcgagaa aaccatctcc 660aaagccaaag ggcagccccg agaaccacag
gtgtacaccc tgcccccatc ccgggaggag 720atgaccaaga accaggtcag
cctgacctgc ctggtcaaag gcttctatcc cagcgacatc 780gccgtggagt
gggagagcaa tgggcagccg gagaacaact acaagaccac gcctcccgtg
840ctggactccg acggctcctt cttcctctat agcaagctca ccgtggacaa
gagcaggtgg 900cagcagggga acgtcttctc atgctccgtg atgcatgagg
ctctgcacaa ccactacacg 960cagaagagcc tctccctgtc tccgggtaaa
990135106PRTHomo sapiens 135Thr Val Ala Ala Pro Ser Val Phe Ile Phe
Pro Pro Ser Asp Glu Gln 1 5 10 15 Leu Lys Ser Gly Thr Ala Ser Val
Val Cys Leu Leu Asn Asn Phe Tyr 20 25 30 Pro Arg Glu Ala Lys Val
Gln Trp Lys Val Asp Asn Ala Leu Gln Ser 35 40 45 Gly Asn Ser Gln
Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr 50 55 60 Tyr Ser
Leu Ser Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys 65 70 75 80
His Lys Val Tyr Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro 85
90 95 Val Thr Lys Ser Phe Asn Arg Gly Glu Cys 100 105 136318DNAHomo
sapiens 136actgtggctg caccatctgt cttcatcttc ccgccatctg atgagcagtt
gaaatctgga 60actgcctctg ttgtgtgcct gctgaataac ttctatccca gagaggccaa
agtacagtgg 120aaggtggata acgccctcca atcgggtaac tcccaggaga
gtgtcacaga gcaggacagc 180aaggacagca cctacagcct cagcagcacc
ctgacgctga gcaaagcaga ctacgagaaa 240cacaaagtct acgcctgcga
agtcacccat cagggcctga gctcgcccgt cacaaagagc 300ttcaacaggg gagagtgt
31813755PRTArtificial SequenceDescription of Artificial Sequence
Synthetic polypeptide 137Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly
Gly Ser His Ile Gln Ile 1 5 10 15 Pro Pro Gly Leu Thr Glu Leu Leu
Gln Gly Tyr Thr Val Glu Val Leu 20 25 30 Arg Gln Gln Pro Pro Asp
Leu Val Glu Phe Ala Val Glu Tyr Phe Thr 35 40 45 Arg Leu Arg Glu
Ala Arg Ala 50 55 13829PRTArtificial SequenceDescription of
Artificial Sequence Synthetic peptide 138Gly Ser Gly Gly Gly Gly
Ser Gly Gly Gly Gly Ser Gln Ile Glu Tyr 1 5 10 15 Leu Ala Lys Gln
Ile Val Asp Asn Ala Ile Gln Gln Ala 20 25 13922PRTArtificial
SequenceDescription of Artificial Sequence Synthetic peptide 139Arg
Ser Gln Ser Arg Ser Arg Tyr Tyr Arg Gln Arg Gln Arg Ser Arg 1 5 10
15 Arg Arg Arg Arg Arg Ser 20 140164PRTArtificial
SequenceDescription of Artificial Sequence Synthetic polypeptide
140Gln Asp Trp Leu Thr Phe Gln Lys Lys His Ile Thr Asn Thr Arg Asp
1 5 10 15 Val Asp Cys Asp Asn Ile Met Ser Thr Asn Leu Phe His Cys
Lys Asp 20 25 30 Lys Asn Thr Phe Ile Tyr Ser Arg Pro Glu Pro Val
Lys Ala Ile Cys 35 40 45 Lys Gly Ile Ile Ala Ser Lys Asn Val Leu
Thr Thr Ser Glu Phe Tyr 50 55 60 Leu Ser Asp Cys Asn Val Thr Ser
Arg Pro Cys Lys Tyr Lys Leu Lys 65 70 75 80 Lys Ser Thr Asn Lys Phe
Cys Val Thr Cys Glu Asn Gln Ala Pro Val 85 90 95 His Phe Val Gly
Val Gly Ser Cys Gly Gly Gly Gly Ser Leu Glu Cys 100 105 110 Gly His
Ile Gln Ile Pro Pro Gly Leu Thr Glu Leu Leu Gln Gly Tyr 115 120 125
Thr Val Glu Val Leu Arg Gln Gln Pro Pro Asp Leu Val Glu Phe Ala 130
135 140 Val Glu Tyr Phe Thr Arg Leu Arg Glu Ala Arg Ala Val Glu His
His 145 150 155 160 His His His His
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