U.S. patent application number 15/990401 was filed with the patent office on 2019-01-31 for combination therapies employing gitr binding molecules.
The applicant listed for this patent is GITR, Inc.. Invention is credited to Paul D. Ponath, Jose F. Ponte, Michael Rosenzweig.
Application Number | 20190030162 15/990401 |
Document ID | / |
Family ID | 40229356 |
Filed Date | 2019-01-31 |
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United States Patent
Application |
20190030162 |
Kind Code |
A1 |
Ponte; Jose F. ; et
al. |
January 31, 2019 |
Combination Therapies Employing GITR Binding Molecules
Abstract
The present invention provides combination therapies that employ
a GITR binding molecule in combination with one or more additional
agents.
Inventors: |
Ponte; Jose F.; (Weymouth,
MA) ; Ponath; Paul D.; (San Francisco, CA) ;
Rosenzweig; Michael; (Boston, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GITR, Inc. |
Cambridge |
MA |
US |
|
|
Family ID: |
40229356 |
Appl. No.: |
15/990401 |
Filed: |
May 25, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14981764 |
Dec 28, 2015 |
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15990401 |
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14081120 |
Nov 15, 2013 |
9241992 |
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14981764 |
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12218187 |
Jul 11, 2008 |
8591886 |
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14081120 |
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61126431 |
May 5, 2008 |
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61001021 |
Oct 30, 2007 |
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60959246 |
Jul 12, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 35/04 20180101;
A61P 15/00 20180101; A61P 13/12 20180101; C07K 2317/565 20130101;
C07K 16/2878 20130101; A61P 35/02 20180101; A61K 45/06 20130101;
A61P 13/10 20180101; A61P 35/00 20180101; A61K 2039/507 20130101;
C07K 2317/24 20130101; A61P 43/00 20180101; A61K 39/3955 20130101;
A61K 31/664 20130101; A61K 31/704 20130101; C07K 16/2818 20130101;
A61P 25/00 20180101; A61P 1/16 20180101; A61K 31/519 20130101; A61K
31/7068 20130101; C07K 2317/51 20130101; A61P 17/00 20180101; C07K
2317/567 20130101; A61P 19/00 20180101; A61P 11/00 20180101; C07K
2317/75 20130101; A61K 31/337 20130101; A61K 39/39558 20130101;
C07K 2317/515 20130101; A61P 25/02 20180101; A61K 31/513 20130101;
A61P 1/04 20180101; A61P 1/18 20180101; A61K 39/39541 20130101;
A61P 1/02 20180101; A61K 31/337 20130101; A61K 2300/00 20130101;
A61K 31/513 20130101; A61K 2300/00 20130101; A61K 31/519 20130101;
A61K 2300/00 20130101; A61K 31/7068 20130101; A61K 2300/00
20130101; A61K 39/39541 20130101; A61K 2300/00 20130101 |
International
Class: |
A61K 39/395 20060101
A61K039/395; A61K 31/513 20060101 A61K031/513; A61K 31/519 20060101
A61K031/519; A61K 31/664 20060101 A61K031/664; A61K 31/704 20060101
A61K031/704; A61K 31/7068 20060101 A61K031/7068; C07K 16/28
20060101 C07K016/28; A61K 31/337 20060101 A61K031/337; A61K 45/06
20060101 A61K045/06 |
Claims
1-64. (canceled)
65. A method for treating a subject having a tumor, the method
comprising administering a GITR-binding antibody, or an
antigen-binding fragment thereof, and a therapy, to the subject,
wherein the GITR-binding antibody or the antigen-binding fragment
acts as a GITR agonist, and the therapy is administered at a
separate time from the GITR-binding antibody or the antigen-binding
fragment at least once, wherein the therapy is a chemotherapeutic
agent selected from the group consisting of an antimetabolite, an
agent that affects microtubule formation, an alkylating agent, and
a cytotoxic antibiotic, and wherein the GITR-binding antibody or
antigen-binding fragment comprises: the heavy chain complementarity
determining regions (CDRs) set forth in SEQ ID NOs.: 1, 2, and 4 or
in SEQ ID NOs.: 1, 3, and 4; and the light chain CDRs set forth in
SEQ ID NOs.: 5, 6, and 7.
66. The method of claim 65, wherein the method results in
inhibition of tumor growth.
67. The method of claim 65, wherein the method results in reduction
in tumor size.
68. The method of claim 65, wherein the method results in reduction
in the number of tumors.
69. The method of claim 65, wherein the method decreases tumor
burden in the subject.
70. The method of claim 65, wherein the method prolongs survival of
the subject.
71. The method of claim 65, wherein the separate in time
administration comprises administration of the therapy to the
subject prior to administration of the GITR-binding antibody or the
antigen-binding fragment.
72. The method of claim 65, wherein the GITR-binding antibody or
the antigen-binding fragment acts synergistically with the
therapy.
73. The method of claim 72, wherein the separate in time
administration comprises administration of the therapy to the
subject prior to administration of the GITR-binding antibody or the
antigen-binding fragment.
74. The method of claim 65, wherein the GITR agonist activity of
the GITR-binding antibody or the antigen-binding fragment comprises
increasing T cell effector responses.
75. The method of claim 65, wherein the chemotherapeutic agent is
an antimetabolite.
76. The method of claim 75, wherein the antimetabolite is a
nucleoside analogue.
77. The method of claim 75, wherein the antimetabolite is selected
from the group consisting of Aminopterin, Methotrexate, Pemetrexed,
Raltitrexed, Cladribine, Clofarabine, Fludarabine, Mercaptopurine,
Pentostatin, Thioguanine, Capecitabine, Cytaribine, Fluorouracil,
Floxuridine, and Gemcitabine.
78. The method of claim 65, wherein the chemotherapeutic agent is
an agent that affects microtubule formation.
79. The method of claim 78, wherein the agent that affects
microtubule formation is selected from the group consisting of
paclitaxel, docetaxel, vincristine, vinblastine, vindesine,
vinorelbin, taxotere, etoposide, and teniposide.
80. The method of claim 65, wherein the chemotherapeutic agent is
an alkylating agent.
81. The method of claim 80, wherein the alkylating agent is
cyclophosphamide.
82. The method of claim 65, wherein the chemotherapeutic agent is a
cytotoxic antibiotic.
83. The method of claim 82, wherein the cytotoxic antibiotic is a
topoisomerase II inhibitor.
84. The method of claim 83, wherein the topoisomerase II inhibitor
is doxorubicin
85. The method of claim 65, wherein the chemotherapeutic agent is
Gemcitabine.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application, 60/959,246, filed on Jul. 12, 2007, titled
"Combination Therapies Employing GITR Binding Molecules",
61/001,021, filed on Oct. 30, 2007, titled "Combination Therapies
Employing GITR Binding Molecules", and U.S. Ser. No. 61/126,431,
filed on May 5, 2008, titled "Combination Therapies Employing GITR
Binding Molecules", the entire contents of each are hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Cancer is one of the most prevalent health problems in the
world today, affecting approximately one in five individuals in the
United States. A variety of chemotherapeutic agents are routinely
employed to combat cancer. Unfortunately, many of these drugs have
some toxicity at the doses which are effective against tumors. In
addition, chemotherapy resistance is a major cause of cancer
treatment failure. Strategies for improving cancer treatment have
been developed over the years, but there is still a need for
effective therapies. Methods of enhancing the anti-tumor effects of
chemotherapeutics would be useful for treating or reducing the
advancement, severity or effects of neoplasia in subjects (e.g.,
humans).
SUMMARY OF THE INVENTION
[0003] The present invention is based, at least in part, on the
discovery that combination therapies employing a GITR binding
molecule, e.g., an anti-GITR antibody, and at least one additional
agent, which is not a GITR binding molecule, (e.g., a
chemotherapeutic agent) are more effective at treating and/or
preventing cancer and/or reducing the size of certain tumors than
the administration of an agent or agents without a GITR binding
molecule. Moreover, in one embodiment, a combination therapy of the
invention has an improved safety profile. For example, in one
embodiment, because the combination therapy of the invention is
more effective, at least one of the agents may be used at a dose
lower than that required for efficacy when used alone.
[0004] Accordingly, in one aspect the present invention provides a
method for inhibiting tumor cell growth in a subject, comprising
administering a GITR binding molecule, or an antigen-binding
fragment thereof, and one or more cycles of at least one additional
agent to the subject, such that tumor cell growth is inhibited in
the subject.
[0005] In another aspect, the invention provides a method for
reducing tumor size in a subject having a tumor, comprising
administering a GITR binding molecule, or an antigen-binding
fragment thereof, and one or more cycles of at least one additional
agent to the subject, such that the tumor size is reduced.
[0006] In one embodiment, the at least one additional agent is
administered to the subject prior to administration of the GITR
binding molecule, or antigen-binding fragment thereof. In another
embodiment, the at least one additional agent is administered to
the subject concomitantly with the GITR binding molecule, or
antigen-binding fragment thereof. In yet another embodiment, the at
least one additional agent is administered to the subject following
administration of the GITR binding molecule, or antigen-binding
fragment thereof.
[0007] In one embodiment, the at least one additional agent is a
chemotherapeutic agent. In one embodiment, the chemotherapeutic
agent is an antimetabolite. In one embodiment, the antimetabolite
is selected from the group consisting of Aminopterin, Methotrexate,
Pemetrexed, Raltitrexed, Cladribine, Clofarabine, Fludarabine,
Mercaptopurine, Pentostatin, Thioguanine, Capecitabine, Cytarabine,
Fluorouracil, Floxuridine, and Gemcitabine. In one embodiment, the
antimetabolite is a nucleoside analogue. In one embodiment, the
nucleoside analogue is gemcitabine. In another embodiment, the
nucleoside analogue is fluorouracil. In one embodiment, the
chemotherapeutic agent is an agent that affects microtubule
formation. In one embodiment, the agent that affects microtubule
formation is selected from the group consisting of: paclitaxel,
docetaxel, vincristine, vinblastine, vindesine, vinorelbin,
taxotere, etoposide, and teniposide. In another embodiment, the
agent that affects microtubule formation is paclitaxel. In one
embodiment, the chemotherapeutic agent is an alkylating agent. In
one embodiment, the alkylating agent is cyclophosphamide. In one
embodiment, the chemotherapeutic agent is a cytotoxic antibiotic.
In one embodiment, the cytotoxic antibiotic is a topoisomerase II
inhibitor. In one embodiment, the topoisomerase II inhibitor is
doxorubicin.
[0008] In one embodiment, the GITR binding molecule is a humanized
antibody or antibody fragment thereof. In one embodiment, the GITR
binding molecule is a human antibody or antibody fragment thereof.
In one embodiment, the humanized antibody comprises the CDRs shown
in SEQ ID NOs.:1, 2 or 3, 4, 5, 6, or 7. In another embodiment, the
GITR binding molecule is a chimeric antibody or antibody fragment
thereof.
[0009] In one embodiment, the type of tumor is selected from the
group consisting of: pancreatic cancer, melanoma, breast cancer,
lung cancer, bronchial cancer, colorectal cancer, prostate cancer,
stomach cancer, ovarian cancer, urinary bladder cancer, brain or
central nervous system cancer, peripheral nervous system cancer,
esophageal cancer, cervical cancer, uterine or endometrial cancer,
cancer of the oral cavity or pharynx, liver cancer, kidney cancer,
testicular cancer, biliary tract cancer, small bowel or appendix
cancer, salivary gland cancer, thyroid gland cancer, adrenal gland
cancer, osteosarcoma, chondrosarcoma, and cancer of hematological
tissues. In one embodiment, the tumor is a colon tumor. In one
embodiment, the colon tumor is an adenocarcinoma. In another
embodiment, the tumor is selected from the group consisting of a
colon tumor, a lung tumor, a breast tumor, a stomach tumor, a
prostate tumor, a cervical tumor, a vaginal tumor, and a pancreatic
tumor. In yet another embodiment, the tumor is at a stage selected
from the group consisting of Stage I, Stage II, Stage III, and
Stage IV.
[0010] In one embodiment, the tumor is at least about 0.5
mm.times.0.5 mm. In another embodiment, the tumor is at least about
1 mm.times.1 mm. In yet another embodiment, the tumor has a volume
of at least about 100 mm.sup.3.
[0011] In one embodiment, the tumor is metastatic.
[0012] In one embodiment, the administration of a GITR binding
molecule, or an antigen-binding fragment thereof, and at least one
chemotherapeutic agent results in an inhibition of tumor size by at
least about 42% to at least about 90%.
[0013] In another aspect, the invention provides a method for
reducing tumor size in a subject having adenocarcinoma of the colon
comprising administering an anti-GITR antibody, or an
antigen-binding fragment thereof, and one or more cycles of
gemcitabine to the subject, such that the tumor size is
reduced.
[0014] In one embodiment, the tumor is an established tumor at the
initiation of treatment.
[0015] In another aspect, the invention provides a method for
reducing tumor size in a subject having melanoma comprising
administering a GITR antibody, or an antigen-binding fragment
thereof, and one or more cycles of paclitaxel to the subject, such
that the tumor size is reduced.
[0016] In one embodiment, the tumor is an established tumor at the
initiation of treatment. In another embodiment, the tumor is a
secondary tumor at the initiation of treatment.
[0017] In yet another aspect, the invention provides a method for
reducing tumor size in a subject having adenocarcinoma of the colon
comprising administering a GITR antibody, or an antigen-binding
fragment thereof, and one or more cycles of cyclophosphamide to the
subject, such that the tumor size is reduced.
[0018] In one embodiment, the tumor is an established tumor at the
initiation of treatment. In another embodiment, the tumor is a
secondary tumor at the initiation of treatment.
[0019] In another aspect, the invention provides a method for
reducing tumor size in a subject having adenocarcinoma of the colon
comprising administering a GITR antibody, or an antigen-binding
fragment thereof, and one or more cycles of fluorouracil to the
subject, such that the tumor size is reduced.
[0020] In one embodiment, the tumor is an established tumor at the
initiation of treatment. In another embodiment, the tumor is a
secondary tumor at the initiation of treatment.
[0021] In another aspect, the invention provides a method for
reducing tumor size in a subject having adenocarcinoma of the colon
comprising administering a GITR antibody, or an antigen-binding
fragment thereof, and one or more cycles of doxorubicin to the
subject, such that the tumor size is reduced.
[0022] In one embodiment, the tumor is an established tumor at the
initiation of treatment. In another embodiment, the tumor is a
secondary tumor at the initiation of treatment.
[0023] In one embodiment, the anti-GITR antibody is a humanized
antibody or antibody fragment thereof. In one embodiment, the
humanized antibody comprises the CDRs shown in SEQ ID NOs.:1, 2 or
3, 4, 5, 6, or 7. In another embodiment, the GITR binding molecule
is a chimeric antibody or antibody fragment thereof.
[0024] Yet another aspect of the invention provides a kit
comprising: a) a packaging material; b) a GITR binding molecule, or
antigen-binding fragment thereof; and c) a label or package insert
contained within the packaging material indicating that the GITR
binding molecule, or antigen-binding fragment thereof, can be
administered with at least one additional agent.
[0025] In one embodiment, the at least one additional agent is a
chemotherapeutic agent. In one embodiment, the chemotherapeutic
agent is an antimetabolite. In one embodiment, the antimetabolite
is a nucleoside analogue. In one embodiment, the nucleoside
inhibitor is gemcitabine. In another embodiment, the nucleoside
analogue is fluorouracil. In one embodiment, the chemotherapeutic
agent is an agent that affects microtubule formation. In one
embodiment, the agent that affects microtubule formation is
selected from the group consisting of: paclitaxel, docetaxel,
vincristine, vinblastine, vindesine, vinorelbin, taxotere,
etoposide, and teniposide. In another embodiment, the agent that
affects microtubule formation is paclitaxel. In one embodiment, the
chemotherapeutic agent is an alkylating agent. In one embodiment,
the alkylating agent is cyclophosphamide. In one embodiment, the
chemotherapeutic agent is a cytotoxic antibiotic. In one
embodiment, the cytotoxic antibiotic is a topoisomerase II
inhibitor. In one embodiment, the topoisomerase II inhibitor is
doxorubicin.
[0026] In one embodiment, the GITR binding molecule is a humanized
antibody or antibody fragment thereof. In one embodiment, the
humanized antibody comprises the CDRs shown in SEQ ID NOs.:1, 2 or
3, 4, 5, 6, or 7. In another embodiment, the GITR binding molecule
is a chimeric antibody or antibody fragment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 depicts a graph showing the effect of the nucleoside
analog, gemcitabine (Gemzar) (80 mg/kg), in combination with the
anti-GITR antibody, 2F8 (0.4 mg), on tumor volume over the course
of treatment as compared to the effect of gemcitabine alone, 2F8
alone, and a vehicle control.
[0028] FIG. 2 depicts a graph showing the effect of the nucleoside
analog, gemcitabine (Gemzar) (80 mg/kg), in combination with the
anti-GITR antibody, 2F8 (0.4 mg), on median survival time
(Kaplan-Meier Survival Curve) over the course of treatment as
compared to the effect of gemcitabine alone, 2F8 alone, and a
vehicle control.
[0029] FIG. 3 depicts a graph showing the effect of the nucleoside
analog, gemcitabine (Gemzar) (80 mg/kg), in combination with the
anti-GITR antibody, 2F8 (0.4 mg), on the number of metastatic
tumors over the course of treatment as compared to the effect of
gemcitabine alone, 2F8 alone, and a vehicle control.
[0030] FIG. 4 depicts a graph showing the effect of an agent that
affects microtubule formation, paclitaxel (Taxol.RTM.) (10 mg/kg),
in combination with the anti-GITR antibody, 2F8 (0.4 mg), tumor
volume over the course of treatment as compared to the effect of
paclitaxel alone, 2F8 alone, and a vehicle control.
[0031] FIG. 5 depicts a graph showing the effect of the alkylating
agent, cyclophosphamide (Cytoxan) (150 mg/kg), in combination with
the anti-GITR antibody, 2F8 (0.4 mg), on tumor volume over the
course of treatment as compared to the effect of cyclophosphamide
alone, and a vehicle control.
[0032] FIG. 6 depicts a graph showing the effect of the nucleoside
analog, Fluorouracil (5-FU) (75 mg/kg), in combination with the
anti-GITR antibody, 2F8 (0.4 mg), on tumor volume over the course
of treatment as compared to the effect of Fluorouracil alone, and a
vehicle control.
[0033] FIG. 7 depicts a graph showing the effect of the
topoisomerase II inhibitor, doxorubicin (Adriamycin) (5 mg/kg), in
combination with the anti-GITR antibody, 2F8 (0.4 mg), on tumor
volume over the course of treatment as compared to the effect of
Fluorouracil alone, and a vehicle control.
[0034] FIG. 8 depicts a graph showing the effect of the alkylating
agent, cyclophosphamide (Cytoxan) (150 mg/kg), in combination with
the anti-GITR antibody, 2F8 (0.4 mg), on tumor volume over the
course of treatment as compared to the effect of cyclophosphamide
alone, and a vehicle control.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The present invention provides, in part, methods and kits
for the treatment of cancer. More specifically, it has been shown
that combination therapy employing an GITR binding molecule, e.g.,
an anti-GITR antibody, and at least one additional agent, which is
not a GITR binding molecule, (e.g., a chemotherapeutic agent) is
more effective at reducing the size of certain tumors than either
agent alone.
[0036] Glucocorticoid-induced tumor necrosis factor (TNF) receptor
family-related gene (GITR), also known as TNF receptor superfamily
member 18 (TNFRSF18), is a type I transmembrane protein with
homology to TNF receptor family members (Nocentini G, et al. (1997)
Proc Natl Acad Sci USA 94:6216-21; Gurney A L, et al. (1999) Curr
Biol 9:215-8). GITR is expressed at low levels on resting CD4+ and
CD8+ T cells and up-regulated following T-cell activation. Ligation
of GITR provides a costimulatory signal that enhances both CD4+ and
CD8+ T-cell proliferation and effector functions, (Kohm A P, et al.
(2004) J Immunol 172:4686-90; Kanamaru F, et al. (2004) J Immunol
172:7306-14; Ronchetti S, et al. (2004) Eur J Immunol 34:613-22;
Tone M, et al. (2003) Proc Natl Acad Sci USA 100:15059-64; Stephens
G L, et al. (2004) J Immunol 2004; 173:5008-20). In addition, GITR
is expressed constitutively at high levels on regulatory T cells.
Although GITR has previously been shown to enhance immune responses
to certain protein antigens, it has not previously been shown to
enhance the anti-tumor effects of agents used to combat cancer.
[0037] In order that the present invention may be more readily
understood, certain terms are first defined.
I. Definitions
[0038] For convenience, before further description of the present
invention, certain terms employed in the specification, examples
and appended claims are defined here.
[0039] The singular forms "a", "an", and "the" include plural
references unless the context clearly dictates otherwise.
[0040] The term "administering" includes any method of delivery of
a pharmaceutical composition or therapeutic agent into a subject's
system or to a particular region in or on a subject. The phrases
"systemic administration," "administered systemically", "peripheral
administration", and "administered peripherally" as used herein
mean the administration of a compound, drug or other material other
than directly into the central nervous system, such that it enters
the subject's system and, thus, is subject to metabolism and other
like processes, for example, subcutaneous administration.
"Parenteral administration" and "administered parenterally" means
modes of administration other than enteral and topical
administration, usually by injection, and includes, without
limitation, intravenous, intramuscular, intraarterial, intrathecal,
intracapsular, intraorbital, intracardiac, intradermal,
intraperitoneal, transtracheal, subcutaneous, subcuticular,
intra-articular, subcapsular, subarachnoid, intraspinal and
intrasternal injection and infusion.
[0041] The term "glucocorticoid-induced TNF receptor" (abbreviated
herein as "GITR"), also known as TNF receptor superfamily 18
(TNFRSF18), TEASR, and 312C2, as used herein, refers to a member of
the tumor necrosis factor/nerve growth factor receptor family. GITR
is a 241 amino acid type I transmembrane protein characterized by
three cysteine pseudorepeats in the extracellular domain and
specifically protects T-cell receptor-induced apoptosis, although
it does not protect cells from other apoptotic signals, including
Fas triggering, dexamethasone treatment, or UV irradiation
(Nocentini, G, et al. (1997) Proc. Natl. Acad. Sci., USA
94:6216-622). The nucleic acid and amino acid sequences of human
GITR (hGITR), of which there are three splice variants, are known
and can be found in, for example GenBank Accession Nos.
gi:40354198, gi:23238190, gi:23238193, and gi:23238196.
[0042] The term "binding molecule" as used herein includes
molecules that contain at least one antigen binding site that
specifically binds to its target. For example, in one embodiment, a
binding molecule for use in the methods of the invention comprises
an immunoglobulin antigen binding site or the portion of a ligand
molecule that is responsible for receptor binding.
[0043] In one embodiment, the binding molecule comprises at least
two binding sites. In one embodiment, the binding molecule
comprises two binding sites. In one embodiment, the binding
molecules comprise three binding sites. In another embodiment, the
binding molecule comprises four binding sites.
[0044] The term "GITR binding molecule" refers to a molecule that
comprises at least one GITR binding site. Examples of GITR binding
molecules which are suitable for use in the methods and kits of the
invention include, but are not limited to, binding molecules
described in, for example, US20070098719, US20050014224, or
WO05007190, each of which is incorporated in its entirety by
reference herein, or binding molecules comprising CDRs set forth in
one of US20070098719, 0520050014224, or WO05007190. In another
embodiment, a GITR binding molecule may comprise one or more of the
CDRs set forth in SEQ ID NOs.:1, 2 or 3, 4, 5, 6, or 7. [SEQ ID
NO.:1 (GFSLSTSGMGVG (Heavy Chain CDR1)), SEQ ID NO.:2
(HIWWDDDKYYNPSLKS (HC CDR2N)), SEQ ID NO.:4 (TRRYFPFAY (HC CDR3)),
SEQ ID NO.:5 (KASQNVGTNVA (Light Chain CDR1)), SEQ ID NO.:6
(SASYRYS (LC CDR2)), SEQ ID NO.:7 (QQYNTDPLT (LC CDR3)), and SEQ ID
NO:3 (HIWWDDDKYYQPSLKS (HC CDR2Q))]. In one embodiment, a binding
molecule comprises 1 CDR. In another embodiment, a binding molecule
comprises 2 CDRs. In another embodiment, a binding molecule
comprises 3 CDRs. In another embodiment, a binding molecule
comprises 4 CDRs. In another embodiment, a binding molecule
comprises 5 CDRs. In yet another embodiment, a binding molecule
comprises all 6 CDRs. Exemplary GITR binding molecules suitable for
use in the methods of the invention also include commercially
available GITR binding molecule, such as MAB689, available from
R&D Systems.
[0045] By "specifically binds" it is meant that the binding
molecules exhibit essentially background binding to non-GITR
molecules. An isolated binding molecule that specifically binds
GITR may, however, have cross-reactivity to GITR molecules from
other species.
[0046] As used herein, the term binding molecule includes,
antibodies (including full length antibodies), monoclonal
antibodies (including full length monoclonal antibodies),
polyclonal antibodies, multispecific antibodies (e.g., bispecific
antibodies), human, humanized or chimeric antibodies, antibody
fragments, e.g., Fab fragments, F(ab') fragments, fragments
produced by a Fab expression library, epitope-binding fragments of
any of the above, and engineered forms of antibodies (i.e.,
molecules comprising binding sites derived from antibody
molecules), e.g., scFv molecules or molecules comprising scFv
molecule, so long as they exhibit the desired activity, e.g.,
binding to GITR. In one embodiment, the GITR binding molecules for
use in the combination therapies of the invention bind to GITR on T
cells and dendritic cells. In one embodiment, the GITR binding
molecules for use in the combination therapies of the invention are
characterized by one or more of: binding to hGITR with high
affinity, agonizing GITR activity (e.g., in the presence of a
stimulating agent, e.g., CD3), and increasing humoral and/or T cell
effector responses.
[0047] In one embodiment, the binding molecules of the invention
are "antibody" or "immunoglobulin" molecules, e.g., naturally
occurring antibody or immunoglobulin molecules or genetically
engineered antibody molecules that bind antigen in a manner similar
to antibody molecules. As used herein, the term "immunoglobulin"
includes a polypeptide having a combination of two heavy and two
light chains whether or not it possesses any relevant specific
immunoreactivity. "Antibodies" refers to such assemblies which have
significant known specific immunoreactive activity to an antigen.
Antibodies and immunoglobulins comprise light and heavy chains,
with or without an interchain covalent linkage between them. Basic
immunoglobulin structures in vertebrate systems are relatively well
understood.
[0048] The generic term "immunoglobulin" comprises five distinct
classes of antibody that can be distinguished biochemically. All
five classes of antibodies are clearly within the scope of the
present invention. With regard to IgG, immunoglobulins comprise two
identical light polypeptide chains of molecular weight
approximately 23,000 Daltons, and two identical heavy chains of
molecular weight 53,000-70,000. The four chains are joined by
disulfide bonds in a "Y" configuration wherein the light chains
bracket the heavy chains starting at the mouth of the "Y" and
continuing through the variable region.
[0049] Both the light and heavy chains are divided into regions of
structural and functional homology. The terms "constant" and
"variable" are used functionally. In this regard, it will be
appreciated that the variable domains of both the light (VL) and
heavy (VH) chain portions determine antigen recognition and
specificity. Conversely, the constant domains of the light chain
(CL) and the heavy chain (CHI, CH2 or CH3) confer important
biological properties such as secretion, transplacental mobility,
Fc receptor binding, complement binding, and the like. By
convention the numbering of the constant region domains increases
as they become more distal from the antigen binding site or
amino-terminus of the antibody. The N-terminus is a variable region
and at the C-terminus is a constant region; the CH3 and CL domains
actually comprise the carboxy-terminus of the heavy and light
chain, respectively.
[0050] Light chains are classified as either kappa or lambda
(.kappa., .lamda.). Each heavy chain class may be bound with either
a kappa or lambda light chain. In general, the light and heavy
chains are covalently bonded to each other, and the "tail" portions
of the two heavy chains are bonded to each other by covalent
disulfide linkages or non-covalent linkages when the
immunoglobulins are generated either by hybridomas, B cells or
genetically engineered host cells. In the heavy chain, the amino
acid sequences run from an N-terminus at the forked ends of the Y
configuration to the C-terminus at the bottom of each chain. Those
skilled in the art will appreciate that heavy chains are classified
as gamma, mu, alpha, delta, or epsilon, (.gamma., .mu., .alpha.,
.delta., .epsilon.) with some subclasses among them (e.g.,
.gamma.1-.gamma.4). It is the nature of this chain that determines
the "class" of the antibody as IgG, IgM, IgA IgG, or IgE,
respectively. The immunoglobulin subclasses (isotypes) e.g.,
IgG.sub.1, IgG.sub.2, IgG.sub.3, IgG.sub.4, IgA.sub.1, etc. are
well characterized and are known to confer functional
specialization. Modified versions of each of these classes and
isotypes are readily discernable to the skilled artisan in view of
the instant disclosure and, accordingly, are within the scope of
the instant invention.
[0051] The variable region allows the antibody to selectively
recognize and specifically bind epitopes on antigens. That is, the
V.sub.L domain and V.sub.H domain of an antibody combine to form
the variable region that defines a three dimensional antigen
binding site. This quaternary antibody structure forms the antigen
binding site present at the end of each arm of the Y. More
specifically, the antigen binding site is defined by three
complementary determining regions (CDRs) on each of the V.sub.H and
V.sub.L chains.
[0052] The term "antibody", as used herein, includes whole
antibodies, e.g., of any isotype (IgG, IgA, IgM, IgE, etc.), and
includes antigen binding fragments thereof. Exemplary antibodies
include monoclonal antibodies, polyclonal antibodies, chimeric
antibodies, humanized antibodies, human antibodies, and multivalent
antibodies. Antibodies may be fragmented using conventional
techniques. Thus, the term antibody includes segments of
proteolytically-cleaved or recombinantly-prepared portions of an
antibody molecule that are capable of actively binding to a certain
antigen. Non-limiting examples of proteolytic and/or recombinant
antigen binding fragments include Fab, F(ab')2, Fab', Fv, and
single chain antibodies (sFv) containing a V[L] and/or V[H] domain
joined by a peptide linker.
[0053] The binding molecules of the invention may comprise an
immunoglobulin heavy chain of any isotype (e.g., IgG, IgE, IgM,
IgD, IgA, and IgY), class (e.g., IgG-1, IgG2, IgG3, IgG4, IgA1 and
IgA2) or subclass of immunoglobulin molecule. Binding molecules may
have both a heavy and a light chain.
[0054] An "antigen" is an entity (e.g., a proteinaceous entity or
peptide) to which a binding molecule specifically binds.
[0055] The term "epitope" or "antigenic determinant" refers to a
site on an antigen to which a binding molecule specifically binds:
Epitopes can be formed both from contiguous amino acids or
noncontiguous amino acids juxtaposed by tertiary folding of a
protein. Epitopes formed from contiguous amino acids are typically
retained on exposure to denaturing solvents whereas epitopes formed
by tertiary folding are typically lost on treatment with denaturing
solvents. An epitope typically includes at least 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14 or 15 amino acids in a unique spatial
conformation. Methods of determining spatial conformation of
epitopes include, for example, X-ray crystallography and
2-dimensional nuclear magnetic resonance. See, e.g., Epitope
Mapping Protocols in Methods in Molecular Biology, Vol. 66, G. E.
Morris, Ed. (1996).
[0056] Binding molecules that recognize the same epitope can be
identified in a simple immunoassay showing the ability of one
antibody to block the binding of another antibody to a target
antigen, i.e., a competitive binding assay. Competitive binding is
determined in an assay in which the binding molecule being tested
inhibits specific binding of a reference binding molecule to a
common antigen, such as GITR. Numerous types of competitive binding
assays are known, for example: solid phase direct or indirect
radioimmunoassay (RIA); solid phase direct or indirect enzyme
immunoassay (EIA) sandwich competition assay (see Stalin et al.,
Methods in Enzymology 9:242 (1983)); solid phase direct
biotin-avidin EIA (see Kirkland et al., J. Immunol. 137:3614
(1986)); solid phase direct labeled assay, solid phase direct
labeled sandwich assay (see Harlow and Lane, Antibodies: A
Laboratory Manual, Cold Spring Harbor Press (1988)); solid phase
direct label RIA using I-125 label (see Morel et al., Mol. Immunol.
25(1):7 (1988)); solid phase direct biotin-avidin EIA (Cheung et
al., Virology 176:546 (1990)); and direct labeled RIA. (Moldenhauer
et al., Scand. J. Immunol. 32:77 (1990)). Typically, such an assay
involves the use of purified antigen bound to a solid surface or
cells bearing either of these, an unlabeled test binding molecule
and a labeled reference binding molecule. Competitive inhibition is
measured by determining the amount of label bound to the solid
surface or cells in the presence of the test binding molecule.
Usually the test binding molecule is present in excess. Usually,
when a competing binding molecule is present in excess, it will
inhibit specific binding of a reference binding molecule to a
common antigen by at least 50-55%, 55-60%, 60-65%, 65-70% 70-75% or
more.
[0057] An epitope is also recognized by immunologic cells, for
example, B cells and/or T cells. Cellular recognition of an epitope
can be determined by in vitro assays that measure antigen-dependent
proliferation, as determined by .sup.3H-thymidine incorporation, by
cytokine secretion, by antibody secretion, or by antigen-dependent
killing (cytotoxic T lymphocyte assay).
[0058] The term "monoclonal binding molecule" as used herein refers
to a binding molecule obtained from a population of substantially
homogeneous binding molecules. Monoclonal binding molecules are
highly specific, being directed against a single antigenic site.
Furthermore, in contrast to polyclonal binding molecule
preparations which typically include different binding molecules
directed against different determinants (epitopes), each monoclonal
binding molecule is directed against a single determinant on the
antigen. The modifier "monoclonal" indicates the character of the
binding molecule as being obtained from a substantially homogeneous
population of binding molecules, and is not to be construed as
requiring production of the binding molecule by any particular
method. For example, the monoclonal binding molecules to be used in
accordance with the present invention may be made by the hybridoma
method first described by Kohler, et al., Nature 256:495 (1975), or
may be made by recombinant DNA methods (see, e.g., U.S. Pat. No.
4,816,567). The "monoclonal binding molecules" may also be isolated
from phage antibody libraries using the techniques described in
Clackson, et al., Nature 352:624-628 (1991) and Marks et al., J.
Mol Biol. 222:581-597 (1991), for example.
[0059] The term "chimeric binding molecule" refers to a binding
molecule comprising amino acid sequences derived from different
species. Chimeric binding molecules can be constructed, for example
by genetic engineering, from binding molecule gene segments
belonging to different species.
[0060] The monoclonal binding molecules herein specifically include
"chimeric" binding molecules in which a portion of the heavy and/or
light chain is identical with or homologous to corresponding
sequences in binding molecules derived from a particular species or
belonging to a particular antibody class or subclass, while the
remainder of the chain(s) is identical with or homologous to
corresponding sequences in binding molecules derived from another
species or belonging to another antibody class or subclass, as well
as fragments of such binding molecules, so long as they exhibit the
desired biological activity (U.S. Pat. No. 4,816,567; and Morrison,
et al., Proc. Natl. Acad. Sci. USA 81:6851-6855 (1984)) e.g.,
binding to GITR, e.g., human GITR (hGITR) and increasing T effector
and/or humoral responses.
[0061] "Humanized" forms of non-human (e.g., murine) binding
molecules are antibodies which contain minimal sequence derived
from non-human binding molecule. For the most part, humanized
binding molecules are human binding molecules (accepter/recipient
binding molecule) in which the CDR residues from the hypervariable
region are replaced by CDR residues from a hypervariable region of
a non-human species (donor binding molecule) such as mouse, rat,
rabbit or nonhuman primate having the desired specificity,
affinity, and capacity. In some instances, Fv framework region (FR)
residues of the human binding molecule are altered, e.g., replaced
by or substituted with non-donor residues (e.g., germline
residues), or backmutated to corresponding donor human residues.
Furthermore, humanized binding molecules may comprise residues
which are not found in the recipient binding molecule or in the
donor binding molecule. These modifications are generally made to
further refine binding molecule performance. In general, the
humanized binding molecule will comprise substantially all of at
least one, and typically two, variable domains, in which all or
substantially all of the hypervariable loops correspond to those of
a non-human binding molecule and all or substantially all of the FR
regions are those of a human binding molecule sequence. The
humanized binding molecule optionally also will comprise at least a
portion of a binding molecule constant region (Fc), typically that
of a human binding molecule. For further details, see Jones, et
al., Nature 321:522-525 (1986); Riechmann, et al., Nature
332:323-329 (1988); and Presta, Curr. Op. Struct. Biol. 2:593-596
(1992).
[0062] The term "multispecific" includes binding molecules having
specificity for more than one target antigen. Such molecules have
more than one binding site where each binding site specifically
binds (e.g., immunoreacts with) a different target molecule or a
different antigenic site on the same target.
[0063] In one embodiment, a multispecific binding molecule of the
invention is a bispecific molecule (e.g., antibody, minibody,
domain deleted antibody, or fusion protein) having binding
specificity for at least two targets, e.g., more than one target
molecule or more than one epitope on the same target molecule.
[0064] In one embodiment, modified forms of antibodies can be made
from a whole precursor or parent antibody using techniques known in
the art. Exemplary techniques are discussed in more detail below.
In particularly preferred embodiments both the variable and
constant regions of polypeptides of the invention are human. In one
embodiment, fully human antibodies can be made using techniques
that are known in the art. For example, fully human antibodies
against a specific antigen can be prepared by administering the
antigen to a transgenic animal which has been modified to produce
such antibodies in response to antigenic challenge, but whose
endogenous loci have been disabled. Exemplary techniques that can
be used to make antibodies are described in U.S. Pat. Nos.
6,150,584; 6,458,592; 6,420,140. Other techniques, such as the use
of libraries, are known in the art.
[0065] In one embodiment, a binding molecule of the invention
comprises an antibody molecule, e.g., an intact antibody molecule,
or a fragment of an antibody molecule. In another embodiment, a
binding molecule of the invention is a modified or synthetic
antibody molecule. In one embodiment, a binding molecule of the
invention comprises all or a portion of (e.g., at least one
antigen-binding site from, at least one CDR from) a monoclonal
antibody, a humanized antibody, a chimeric antibody, or a
recombinantly produced antibody.
[0066] In embodiments where the binding molecule is an antibody or
modified antibody, the antigen binding site and the heavy chain
portions need not be derived from the same immunoglobulin molecule.
In this regard, the variable region may be derived from any type of
animal that can be induced to mount a humoral response and generate
immunoglobulins against the desired antigen. As such, the variable
region of the polypeptides may be, for example, of mammalian origin
e.g., may be human, murine, rat, non-human primate (such as
cynomolgus monkeys, macaques, etc.), lupine, camelid (e.g., from
camels, llamas and related species). In another embodiment, the
variable region may be condricthoid in origin (e.g., from
sharks).
[0067] In one embodiment, the binding molecules of the invention
are modified antibodies. As used herein, the term"engineered" or
"modified antibody" includes synthetic forms of antibodies which
are altered such that they are not naturally occurring, e.g.,
antibodies that do not comprise complete heavy chains (such as,
domain deleted antibodies or minibodies); multispecific forms of
antibodies (e.g., bispecific, trispecific, etc.) altered to bind to
two or more different antigens or to different epitopes on a single
antigen); heavy chain molecules joined to scFv molecules and the
like. ScFv molecules are known in the art and are described, e.g.,
in U.S. Pat. No. 5,892,019. In addition, the term "engineered" or
"modified antibody" includes multivalent forms of antibodies (e.g.,
trivalent, tetravalent, etc., antibodies that bind to three or more
copies of the same antigen or different antigens or different
epitopes on the same antigen).
[0068] In one embodiment, the term, "modified antibody" according
to the present invention includes immunoglobulins, antibodies, or
immunoreactive fragments or recombinant forms thereof, in which at
least a fraction of one or more of the constant region domains has
been deleted or otherwise altered (e.g., mutated) so as to provide
desired biochemical characteristics such as the ability to
non-covalently dimerize, increased ability to localize at the site
of a tumor, or altered serum half-life when compared with a whole,
unaltered antibody of approximately the same immunogenicity.
[0069] In one embodiment, the binding molecules of the invention
may be modified to reduce their immunogenicity using art-recognized
techniques. For example, antibodies or polypeptides of the
invention can be humanized, deimmunized, or chimeric antibodies can
be made. These types of antibodies are derived from a non-human
antibody, typically a murine antibody, that retains or
substantially retains the antigen-binding properties of the parent
antibody, but which is less immunogenic in humans. This may be
achieved by various methods, including (a) grafting the entire
non-human variable domains onto human constant regions to generate
chimeric antibodies; (b) grafting at least a part of one or more of
the non-human complementarity determining regions (CDRs) into a
human framework and constant regions with or without retention of
critical framework residues; or (c) transplanting the entire
non-human variable domains, but "cloaking" them with a human-like
section by replacement of surface residues. Such methods are
disclosed in Morrison et al., Proc. Natl. Acad. Sci. 81: 6851-5
(1984); Morrison et al., Adv. Immunol. 44: 65-92 (1988); Verhoeyen
et al., Science 239: 1534-1536 (1988); Padlan, Molec. Immun. 28:
489-498 (1991); Padlan Molec. Immun. 31: 169-217 (1994), and U.S.
Pat. Nos. 5,585,089, 5,693,761 and 5,693,762 all of which are
hereby incorporated by reference in their entirety.
[0070] The term "chemotherapeutic agent", used interchangeably
herein with "chemotherapy agent" and "antineoplastic agent", refers
to a substance that inhibits or prevents the viability and/or
function of cells, and/or causes destruction of cells (cell death),
and/or exerts anti-neoplastic/anti-proliferative effects, for
example, prevents directly or indirectly the development,
maturation or spread of neoplastic tumor cells. The term also
includes such agents that cause a cytostatic effect only and not a
mere cytotoxic effect. As used herein the term chemotherapeutic
agents includes anti-angiogenic agents, tyrosine kinase inhibitors,
protein kinase A inhibitors, members of the cytokine family, and
radioactive isotopes.
[0071] Suitable chemotherapeutic agents according to the invention
are preferably natural or synthetic chemical compounds. There are
large numbers of anti-neoplastic chemical agents available in
commercial use, in clinical evaluation and in pre-clinical
development, which may be used in the combination therapies of the
invention (discussed below).
[0072] The term "biologic" or "biologic agent" refers to any
pharmaceutically active agent made from living organisms and/or
their products which is intended for use as a therapeutic, e.g.,
toxins such as enzymatically active toxins of bacterial, fungal,
plant or animal origin. In one embodiment of the invention,
biologic agents which can be used in combination with a GITR
binding molecule include, but are not limited to e.g., antibodies,
nucleic acid molecules, e.g., antisense nucleic acid molecules,
polypeptides or proteins. Such biologics can be administered in
combination with a GITR binding molecule by administration of the
biologic agent, e.g., prior to the administration of the GITR
binding molecule, concomitantly with the GITR binding molecule, or
after the GITR binding molecule.
[0073] The term "combination therapy", as used herein, refers to a
therapeutic regimen comprising, e.g., a GITR binding molecule and
at least one additional non-GITR binding molecule, e.g., a
chemotherapeutic agent. The GITR binding molecule and the at least
one additional agent may be formulated, for separate administration
or may be formulated for administration together. In one
embodiment, the at least one, additional agent is not a molecule to
which an immune response is desired, e.g., is not a vaccine.
[0074] The term "cancer" or "neoplasia" refers in general to a
maligiant neoplasm or spontaneous growth or proliferation of cells.
Cancer cells are often in the form of a tumor, but such cells may
exist alone within a subject, or may be non-tumorigenic cancer
cells, such as leukemia cells. As used herein, the term "cancer"
includes pre-malignant as well as malignant cancers.
[0075] A subject having "cancer", for example, may have a leukemia,
lymphoma, or other malignancy of blood cells. In one embodiment,
cancer is selected from the group consisting of pancreatic cancer,
melanoma and other forms of skin cancer (e.g., squamous cell
carcinoma) breast cancer, lung cancer, bronchial cancer, colorectal
cancer, prostate cancer, stomach cancer, ovarian cancer, brain or
central nervous system cancer, peripheral nervous system cancer,
esophageal cancer, cervical cancer, uterine or endometrial cancer,
cancer of the head and neck (including cancer of the oral cavity or
nasopharynx), liver and biliary tract cancer, kidney and renal
collecting system, including urinary bladder cancer, testicular
cancer, small bowel or appendix cancer, salivary gland cancer,
thyroid gland cancer, adrenal gland cancer, sarcomas (including
osteosarcoma and chondrosarcoma), and cancer of hematological
tissues.
[0076] In certain embodiments, the subject methods are used to
treat a solid tumor. Exemplary solid tumors include but are not
limited to small and non-small cell lung cancer (NSCLC), testicular
cancer, ovarian cancer, uterine cancer, cervical cancer, pancreatic
cancer, colorectal cancer (CRC), breast cancer, as well as
prostate, gastric, skin, stomach, esophageal, and bladder
cancer.
[0077] In one embodiment, a solid tumor is an adenocarcinoma, e.g.,
of the colon. In one embodiment of the invention, a solid tumor is
a colon tumor. In another embodiment of the invention, a solid
tumor is selected from the group consisting of a colon tumor, a
lung tumor, a breast tumor, a stomach tumor, a prostate tumor, a
cervical tumor, a vaginal tumor, and a pancreatic tumor.
[0078] In one embodiment of the invention, the cancer to be treated
is a melanoma.
[0079] In certain embodiments of the invention, the subject methods
are used to reduce and/or prevent tumor cell proliferation. In
certain embodiments of the invention, the subject methods are used
to reduce and/or prevent tumor metastasis. In another embodiment,
the subject methods are used to reduce the size of a tumor, e.g.,
an established tumor, and/or a secondary tumor, e.g., a metastasis.
As used herein, an "established tumor" is a solid tumor of
sufficient size such that nutrients, i.e., oxygen can no longer
permeate to the center of the tumor from the subject's vasculature
by osmosis and, therefore, the tumor requires its own vascular
supply to receive nutrients.
[0080] In one embodiment, the subject methods are used to treat a
vascularized tumor. The term "vascularized tumor" includes tumors
having the hallmarks of established vasculature. Such tumors are
identified by their size and/or by the presence of markers
associated with blood vessels or angiogenesis. In one embodiment,
the tumor is at least about 0.5 mm.times.0.5 mm. In another
embodiment, the tumor is at least about 1 mm.times.1 mm. In yet
another embodiment, the tumor has a volume of at least about 100
mm.sup.3. In another embodiment, the tumor has a volume of at least
about 200 mm.sup.3. In another embodiment, the tumor has a volume
of at least about 300 mm.sup.3. In another embodiment, the tumor
has a volume of at least about 400 mm.sup.3. In another embodiment,
the tumor has a volume of at least about 500 mm.sup.3. In one
embodiment, the tumor is large enough to be found by palpation or
by using art recognized imaging techniques.
[0081] In another embodiment, the subject methods are used to treat
a solid tumor that is not quiescent and is actively undergoing
exponential growth. In another embodiment, the subject methods are
used to treat a small tumor, such as a micrometastasis, e.g., a
tumor detectable only by histological examination but not by other
techniques.
[0082] The term "effective amount" refers to that amount of
combination therapy which is sufficient to produce a desired result
on a cancerous cell or tumor, including, but not limited to, for
example, reducing tumor size and/or reducing tumor volume of a
solid tumor, either in vitro or in vivo. In one embodiment of the
invention, an effective amount of a combination therapy is the
amount that results in an inhibition of tumor size more than about
10%, more than about 20%, more than about 30%, more than about 35%,
more than about 42%, more than about 43%, more than about 44%, more
than about 45%, more than about 46%, more than about 47%, more than
about 48%, more than about 49%, more than about 50%, more than
about 51%, more than about 52%, more than about 53%, more than
about 54%, more than about 55%, more than about 56%, more than
about 57%, more than about 58%, more than about 59%, more than
about 60%, more than about 65%, more than about 70%, more than
about 75%, more than about 80%, more than about 85%, more than
about 90%, more than about 95%, or more than about 100%.
[0083] The term also includes that amount of a combination therapy
which is sufficient to achieve a desired clinical result, including
but not limited to, for example, preventing recurrence,
ameliorating disease, stabilizing a patient, preventing or delaying
the development of metastasis, or preventing or slowing the
progression of cancer in a patient. An effective amount of the
combination therapy can be determined based on one administration
of each of the agents or repeated administration of at least one of
the agents of the therapy. Methods of detection and measurement of
the indicators above are known to those of ordinary skill in the
art. Such methods include, but are not limited to measuring
reduction in tumor burden, reduction of tumor size, reduction of
tumor volume, reduction in proliferation of secondary tumors,
decreased solid tumor vascularization, alteration in the expression
of genes in tumor tissue or adjacent tissue; presence or absence of
biomarkers, lymph node involvement, histologic grade, detecting the
lack of recurrence of a tumor, a reduced rate of tumor growth,
reduced tumor cell metabolism, and/or nuclear grade.
[0084] In one embodiment of the invention, tumor burden is
determined. "Tumor burden" also referred to as "tumor load", refers
to the total amount of tumor material distributed throughout the
body. Tumor burden refers to the total number of cancer cells or
the total size of tumor(s), throughout the body, including lymph
nodes and bone barrow. Tumor burden can be determined by a variety
of methods known in the art, such as, e.g. by measuring the
dimensions of tumor(s) upon removal from the subject, e.g., using
calipers, or while in the body using imaging techniques, e.g.,
ultrasound, bone scan, computed tomography (CT) or magnetic
resonance imaging (MRI) scans.
[0085] In one embodiment of the invention, tumor size is
determined. The term "tumor size" refers to the total size of the
tumor which can be measured as the length and width of a tumor.
Tumor size may be determined by a variety of methods known in the
art, such as, e.g. by measuring the dimensions of tumor(s) upon
removal from the subject, e.g., using calipers, or while in the
body using imaging techniques, e.g., bone scan, ultrasound, CT or
MRI scans.
[0086] In one embodiment of the invention, tumor size is determined
by determining tumor weight. In one embodiment, tumor weight is
determined by measuring the length of the tumor, multiplying it by
the square of the width of the tumor, and dividing that sum by
2.
[0087] In one embodiment of the invention, tumor size is determined
by determining tumor volume. The term "tumor volume" refers to the
total size of the tumor, which includes the tumor itself plus
affected lymph nodes if applicable. Tumor volume may be determined
by a variety of methods known in the art, such as, e.g. by
measuring the dimensions of tumor(s) upon removal from the subject,
e.g., using calipers, or while in the body using an imaging
techniques, e.g., ultrasound, CT or MRI scans, and calculating the
volume using equations based on, for example, the z-axis diameter,
or on standard shapes such as the sphere, ellipsoid, or cube. In
one embodiment, tumor volume (mm.sup.3) is calculated for a prolate
ellipsoid from 2-dimensional tumor measurements: tumor volume
(mm.sup.3)=(length.times.width.sup.2 [L.times.W.sup.2])/2. Assuming
unit density, tumor volume is converted to tumor weight (i.e., 1
mm.sup.3=1 mg).
[0088] The term "vascularization of a solid tumor" refers to the
formation of blood vessels in a solid tumor. Tumor vacularization
may be determined by a variety of methods known in the art, such
as, e.g. by immunohistochemical analysis of biopsy specimens, or by
imaging techniques, such as sonography of the tumor, angiography,
CT or magnetic MRI scans.
[0089] The term "T/C" is the percentage of the mean tumor weight of
the Treatment group (T) divided by the mean tumor weight of the
Control group (C) multiplied by 100. A % T/C value of 42% or less
is considered indicative of meaningful activity by the National
Cancer Institute (USA).
[0090] The term "% inhibition" with respect to T/C is calculated by
subtracting the % T/C from 100.
[0091] The term "statistically significant" or "statistical
significance" refers to the likelihood that a result would have
occurred by chance, given that an independent variable has no
effect, or, that a presumed null hypothesis is true. Statistical
significance can be determined by obtaining a "P-value" (P) which
refers to the probability value. The p-value indicates how likely
it is that the result obtained by the experiment is due to chance
alone. In one embodiment of the invention, statistical significance
can be determined by obtaining the p-value of the Two-Tailed
One-Sample T-Test. A p-value of less than 0.05 is considered
statistically significant, that is, not likely to be due to chance
alone. Alternatively a statistically significant p-value may be
between about 0.05 to about 0.04; between about 0.04 to about 0.03;
between about 0.03 to about 0.02; between about 0.02 to about 0.01.
Ranges intermediate to the above recited values, e.g., are also
intended to be part of this invention. In certain cases, the
p-value may be less than 0.01. The p-value may be used to determine
whether or not there is any statistically significant reduction in
tumor size and/or any statistically significant increase in
survival when combination therapy is used to treat a subject having
a tumor.
[0092] "Treating cancer" or "treating a subject having cancer"
includes inhibition of the replication of cancer cells, inhibition
of the spread of cancer, reduction in tumor size, lessening or
reducing the number of cancerous cells in the body, and/or
amelioration or alleviation of the symptoms of cancer. A treatment
is considered therapeutic if there is a decrease in mortality
and/or morbidity, and may be performed prophylactically, or
therapeutically.
[0093] A. "patient" or "subject" or "host" refers to either a human
being or non-human animal.
[0094] Various aspects of the invention are described in further
detail in the following subsections.
II. GITR Binding Molecules
[0095] GITR binding molecules for use in the methods of the
invention include binding molecules that specifically bind to GITR
and act as a GITR agonist (as demonstrated by, e.g., increased
effector T cell response and/or increased humoral immunity), such
as, for example, those binding molecules described in
US20070098719, US20050014224, and WO05007190.
[0096] In one embodiment, the GITR binding molecule is an anti-GITR
antibody. Various forms of anti-GITR antibodies can be made using
standard recombinant DNA techniques (Winter and Milstein, Nature,
349, pp. 293-99 (1991)).
[0097] In certain embodiments, the GITR binding molecule may be a
polyclonal antibody. For example, antibodies may be raised in
mammals by multiple subcutaneous or intraperitoneal injections of
the relevant antigen and an adjuvant. This immunization typically
elicits an immune response that comprises production of
antigen-reactive antibodies from activated splenocytes or
lymphocytes. The resulting antibodies may be harvested from the
serum of the animal to provide polyclonal preparations.
[0098] Chimeric and/or humanized binding molecules (i.e., chimeric
and/or humanized immunoglobulins) specific for GITR are also
suitable for use in the methods of the invention. Chimeric and/or
humanized binding molecules have the same or similar binding
specificity and affinity as a mouse or other nonhuman binding
molecules that provide the starting material for construction of a
chimeric or humanized binding molecule.
[0099] A chimeric binding molecule is one whose light and heavy
chain genes have been constructed, typically by genetic
engineering, from immunoglobulin gene segments belonging to
different species. For example, the variable (V) segments of the
genes from a mouse monoclonal binding molecule may be joined to
human constant (C) segments, such as IgG1 or IgG4. Human isotype
IgG1 is preferred. An exemplary chimeric binding molecule is thus a
hybrid protein consisting of the V or antigen-binding domain from a
mouse binding molecule and the C or effector domain from a human
binding molecule.
[0100] In one embodiment, a binding molecule suitable for use in
the methods of the invention comprises a humanized variable region
of the 6C8 binding molecule. In one embodiment, a binding molecule
of the invention comprises at least one humanized 6C8 binding
molecule variable region, e.g., a light chain or heavy chain
variable region.
[0101] As set forth above, the term "humanized binding molecule"
refers to a binding molecule comprising at least one chain
comprising variable region framework residues derived from a human
binding molecule chain (referred to as the accepter antibody or
binding molecule) and at least one complementarity determining
region derived from a mouse-binding molecule, (referred to as the
donor antibody or binding molecule). Humanized binding molecules
can be produced using recombinant DNA technology. See for example,
e.g., Hwang, W. Y. K., et al. (2005) Methods 36:35; Queen et al.,
Proc. Natl. Acad. Sci. USA, (1989), 86:10029-10033; Jones et al.,
Nature, (1986), 321:522-25; Riechmann et al., Nature, (1988),
332:323-27; Verhoeyen et al., Science, (1988), 239:1534-36; Orlandi
et aL, Proc. Natl. Acad. Sci. USA, (1989), 86:3833-37; U.S. Pat.
Nos. 5,225,539; 5,530,101; 5,585,089; 5,693,761; 5,693,762;
6,180,370, Selick et al., WO 90/07861, and Winter, U.S. Pat. No.
5,225,539 (incorporated by reference in their entirety for all
purposes). The constant region(s), if present, are preferably also
derived from a human immunoglobulin.
[0102] In certain embodiments, the humanized antibody is humanized
6C8 or antibody fragment thereof, as described, including the
nucleotide and amino acid sequence thereof, in US20070098719. In
one embodiment, the humanized antibody comprises one or more of the
CDRs shown in SEQ ID NOs.:1, 2 or 3, 4, 5, 6, or 7. In one
embodiment, the humanized antibody comprises CDRs 1, 2 or 3, 4, 5,
6, and 7.
[0103] The humanized binding molecules preferably exhibit a
specific binding affinity for antigen of at least 10.sup.7,
10.sup.8, 10.sup.9, 10.sup.10, 10.sup.11, or 10.sup.12 M.sup.-1.
Usually the upper limit of binding affinity of the humanized
binding molecules for antigen is within a factor of three, four or
five of that of the donor immunoglobulin. Often the lower limit of
binding affinity is also within a factor of three, four or five of
that of donor immunoglobulin. Alternatively, the binding affinity
can be compared to that of a humanized binding molecule having no
substitutions (e.g., a binding molecule having donor CDRs and
accepter FRs, but no FR substitutions). In such instances, the
binding of the optimized binding molecule (with substitutions) is
preferably at least two- to three-fold greater, or three- to
four-fold greater, than that of the unsubstituted binding molecule.
For making comparisons, activity of the various binding molecules
can be determined, for example, by BIACORE (i.e., surface plasmon
resonance using unlabeled reagents) or competitive binding
assays.
[0104] In certain embodiments, a GITR binding molecule is a
chimeric antibody. In one embodiment, a chimeric antibody of the
invention may be a chimeric 6C8 antibody which is described in U.S.
Patent Publication No. US20070098719, the contents of which are
expressly incorporated herein by reference.
[0105] In certain embodiments, a GITR binding molecule is a
monoclonal antibody. In one embodiment, a monoclonal antibody of
the invention may be a humanized 6C8 antibody which is also
described in U.S. Patent Publication No. US20070098719.
[0106] In another embodiment, a binding molecule of the invention
comprises at least one CDR derived from a murine human GITR binding
molecule, e.g., a 6C8 binding molecule. In another embodiment, a
binding molecule of the invention comprises at least one CDR (e.g.,
1, 2, 3, 4, 5, or 6 CDRs) derived from a rat GITR binding molecule,
e.g., a 2F8 binding molecule. As used herein the term "derived
from" a designated protein refers to the origin of the polypeptide.
In one embodiment, the polypeptide or amino acid sequence which is
derived from a particular starting polypeptide is a CDR sequence or
sequence related thereto. In another embodiment, the polypeptide or
amino acid sequence which is derived from a particular starting
polypeptide is a framework (FR) sequence or sequence related
thereto. In one embodiment, the amino acid sequence which is
derived from a particular starting polypeptide is not
contiguous.
[0107] For example, in one embodiment, one, two, three, four, five,
or six CDRs are derived from a murine 6C8 antibody. In one
embodiment, a binding molecule of the invention comprises at least
one heavy or light chain CDR of a murine 6C8 antibody. In another
embodiment, a binding molecule of the invention comprises at least
two CDRs from a murine 6C8 antibody. In another embodiment, a
binding molecule of the invention comprises at least three CDRs
from a murine 6C8 antibody. In another embodiment, a binding
molecule of the invention comprises at least four CDRs from a
murine 6C8 antibody. In another embodiment, a binding molecule of
the invention comprises at least five CDRs from a murine 6C8
antibody. In another embodiment, a binding molecule of the
invention comprises at least six CDRs from a murine 6C8
antibody.
[0108] In one embodiment, a binding molecule of the invention
comprises a polypeptide or amino acid sequence that is essentially
identical to that of a 6C8 antibody, or a portion thereof, e.g., a
CDR, wherein the portion consists of at least 3-5 amino acids, of
at least 5-10 amino acids, at least 10-20 amino acids, at least
20-30 amino acids, or at least 30-50 amino acids, or which is
otherwise identifiable to one of ordinary skill in the art as
having its origin in the starting sequence.
[0109] In another embodiment, the polypeptide or amino acid
sequence which is derived from a particular starting polypeptidc or
amino acid sequence shares an amino acid sequence identity that is
about 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,
96%, 97%, 98%, 99%, with a 6C8 antibody or portion thereof (e.g., a
CDR) or which is otherwise identifiable to one of ordinary skill in
the art as having its origin in the starting sequence.
[0110] It will also be understood by one of ordinary skill in the
art that an anti-GITR binding molecule for use in the methods of
the invention may be modified such that it varies in amino acid
sequence from the molecule from which it was derived. For example,
nucleotide or amino acid substitutions leading to conservative
substitutions or changes at "non-essential" amino acid residues may
be made (e.g., in CDR and/or framework residues) and maintain,
increase, or decrease the ability to bind to GITR, e.g., human
GITR.
[0111] An isolated nucleic acid molecule encoding a non-natural
variant of a polypeptide can be created by introducing one or more
nucleotide substitutions, additions or deletions into the
nucleotide sequence of the binding molecule such that one or more
amino acid substitutions, additions or deletions are introduced
into the encoded protein. Mutations may be introduced by standard
techniques, such as site-directed mutagenesis and PCR-mediated
mutagenesis. In one embodiment, conservative amino acid
substitutions are made at one or more non-essential amino acid
residues. A "conservative amino acid substitution" is one in which
the amino acid residue is replaced with an amino acid residue
having a similar side chain. Families of amino acid residues having
similar side chains have been defined in the art, including basic
side chains (e.g., lysine, arginine, histidine), acidic side chains
(e.g., aspartic acid, glutamic acid), uncharged polar side chains
(e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine,
cysteine), nonpolar side chains (e.g., alanine, valine, leucine,
isoleucine, proline, phenylalanine, methionine, tryptophan),
beta-branched side chains (e.g., threonine, valine, isoleucine) and
aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan,
histidine). Thus, a nonessential amino acid residue in a binding
molecule polypeptide may be replaced with another amino acid
residue from the same side chain family. In another embodiment, a
string of amino acids can be replaced with a structurally similar
string that differs in order and/or composition of side chain
family members.
[0112] Alternatively, in another embodiment, mutations may be
introduced randomly along all or part of the binding molecule
coding sequence.
[0113] Preferred binding molecules for use in the methods of the
invention comprise framework and constant region amino acid
sequences derived from a human amino acid sequence. However,
binding molecules may comprise framework and/or constant region
sequences derived from another mammalian species. For example, a
primate framework region (e.g., non-human primate), heavy chain
portion, and/or hinge portion may be included in the subject
binding molecules. In one embodiment, one or more murine amino
acids may be present in the framework region of a binding
polypeptide, e.g., a human or non-human primate framework amino
acid sequence may comprise one or more amino acid substitutions
and/or backmutations in which the corresponding murine amino acid
residue is present. Preferred binding molecules of the invention
are less immunogenic than the starting 6C8 murine antibody.
[0114] The preparation of monoclonal antibodies is a well-known
process (Kohler et al., Nature, 256:495 (1975)) in which the
relatively short-lived, or mortal, lymphocytes from a mammal which
has been injected with antigen are fused with an immortal tumor
cell line (e.g. a myeloma cell line), thus, producing hybrid cells
or "hybridomas" which are both immortal and capable of producing
the genetically coded antibody of the B cell. The resulting hybrids
are segregated into single genetic strains by selection, dilution,
and regrowth with each individual strain comprising specific genes
for the formation of a single antibody. They produce antibodies
which are homogeneous against a desired antigen and, in reference
to their pure genetic parentage, are termed "monoclonal."
[0115] Hybridoma cells thus prepared are seeded and grown in a
suitable culture medium that preferably contains one or more
substances that inhibit the growth or survival of the unfused,
parental myeloma cells. Those skilled in the art will appreciate
that reagents, cell lines and media for the formation, selection
and growth of hybridomas are commercially available from a number
of sources and standardized protocols are well established.
Generally, culture medium in which the hybridoma cells are growing
is assayed for production of monoclonal antibodies against the
desired antigen. Preferably, the binding specificity of the
monoclonal antibodies produced by hybridoma cells is determined by
immunoprecipitation or by an in vitro assay, such as a
radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay
(ELISA). After hybridoma cells are identified that produce
antibodies of the desired specificity, affinity and/or activity,
the clones may be subcloned by limiting dilution procedures and
grown by standard methods (Goding, Monoclonal Antibodies:
Principles and Practice, pp 59-103 (Academic Press, 1986)). It will
further be appreciated that the monoclonal antibodies secreted by
the subclones may be separated from culture medium, ascites fluid
or serum by conventional purification procedures such as, for
example, protein-A, hydroxylapatite chromatography, gel
electrophoresis, dialysis or affinity.
[0116] In another embodiment, DNA encoding a desired monoclonal
antibody may be readily isolated and sequenced using conventional
procedures (e.g., by using oligonucleotide probes that are capable
of binding specifically to genes encoding the heavy and light
chains of murine antibodies). The isolated and subcloned hybridoma
cells serve as a preferred source of such DNA. Once isolated, the
DNA may be placed into expression vectors, which are then
transfected into prokaryotic or eukaryotic host cells such as E.
coli cells, simian COS cells, Chinese Hamster Ovary (CHO) cells or
myeloma cells that do not otherwise produce immunoglobulins. More
particularly, the isolated DNA (which may be modified as described
herein) may be used to clone constant and variable region sequences
for the manufacture antibodies as described in Newman et al., U.S.
Pat. No. 5,658,570, filed Jan. 25, 1995, which is incorporated by
reference herein. Essentially, this entails extraction of RNA from
the selected cells, conversion to cDNA, and amplification by PCR
using Ig specific primers. Suitable primers for this purpose are
also described in U.S. Pat. No. 5,658,570. As will be discussed in
more detail below, transformed cells expressing the desired
antibody may be grown up in relatively large quantities to provide
clinical and commercial supplies of the immunoglobulin.
[0117] Those skilled in the art will also appreciate that DNA
encoding antibodies or antibody fragments may also be derived from
antibody phage libraries, e.g., using pd phage or Fd phagemid
technology. Exemplary methods are set forth, for example, in EP 368
684 B1; U.S. Pat. No. 5,969,108, Hoogenboom, H. R. and Chames.
2000. Immunol. Today 21:371; Nagy et al. 2002. Nat. Med. 8:801;
Huie et al. 2001. Proc. Natl. Acad. Sci. USA 98:2682; Lui et al.
2002. J. Mol. Biol. 315:1063, each of which is incorporated herein
by reference. Several publications (e.g., Marks et al.
Bio/Technology 10:779-783 (1992)) have described the production of
high affinity human antibodies by chain shuffling, as well as
combinatorial infection and in vivo recombination as a strategy for
constructing large phage libraries. In another embodiment,
Ribosomal display can be used to replace bacteriophage as the
display platform (see, e.g., Hanes et al. 2000. Nat. Biotechnol.
18:1287; Wilson et al. 2001. Proc. Natl. Acad. Sci. USA 98:3750; or
Irving et al. 2001 J. Immunol. Methods 248:31. In yet another
embodiment, cell surface libraries can be screened for antibodies
(Boder et al. 2000. Proc. Natl. Acad. Sci. USA 97:10701; Daugherty
et al. 2000 J. Immunol. Methods 243:211. Such procedures provide
alternatives to traditional hybridoma techniques for the isolation
and subsequent cloning of monoclonal antibodies.
[0118] Yet other embodiments of the present invention comprise the
generation of human or substantially human antibodies in nonhuman
animals, such as transgenic animals harboring one or more human
immunoglobulin transgenes. Such animals may be used as a source for
splenocytes for producing hybridomas, as is described in U.S. Pat.
No. 5,569,825, WO00076310, WO00058499 and WO00037504 and
incorporated by reference herein.
[0119] Yet another highly efficient means for generating
recombinant antibodies is disclosed by Newman, Biotechnology, 10:
1455-1460 (1992). Specifically, this technique results in the
generation of primatized antibodies that contain monkey variable
domains and human constant sequences. This reference is
incorporated by reference in its entirety herein. Moreover, this
technique is also described in commonly assigned U.S. Pat. Nos.
5,658,570, 5,693,780 and 5,756,096 each of which is incorporated
herein by reference.
[0120] In another embodiment, lymphocytes can be selected by
micromanipulation and the variable genes isolated. For example,
peripheral blood mononuclear cells can be isolated from an
immunized mammal and cultured for about 7 days in vitro. The
cultures can be screened for specific IgGs that meet the screening
criteria. Cells from positive wells can be isolated. Individual
Ig-producing B cells can be isolated by FACS or by identifying them
in a complement-mediated hemolytic plaque assay. Ig-producing B
cells can be micromanipulated into a tube and the Vh and Vl genes
can be amplified using, e.g., RT-PCR. The VH and VL genes can be
cloned into an antibody expression vector and transfected into
cells (e.g., eukaryotic or prokaryotic cells) for expression.
[0121] Alternatively, antibody-producing cell lines may be selected
and cultured using techniques well known to the skilled artisan.
Such techniques are described in a variety of laboratory manuals
and primary publications. In this respect, techniques suitable for
use in the invention as described below are described in Current
Protocols in Immunology, Coligan et al., Eds., Green Publishing
Associates and Wiley-Interscience, John Wiley and Sons, New York
(1991) which is herein incorporated by reference in its entirety,
including supplements.
[0122] Variable and constant region domains can be obtained from
existing sources, (e.g., from one or more of the anti-GITR
antibodies described herein) and be incorporated into a modified
binding molecule of the invention. For example, to clone
antibodies, mRNA can be isolated from hybridoma, spleen, or lymph
cells, reverse transcribed into DNA, and antibody genes amplified
by PCR. PCR may be initiated by consensus constant region primers
or by more specific primers based on the published heavy and light
chain DNA and amino acid sequences. PCR also may be used to isolate
DNA clones encoding the antibody light and heavy chains. In this
case the libraries may be screened by consensus primers or larger
homologous probes, such as mouse constant region probes. Numerous
primer sets suitable for amplification of antibody genes are known
in the art (e.g., 5' primers based on the N-terminal sequence of
purified antibodies (Benhar and Pastan. 1994. Protein Engineering
7:1509); rapid amplification of cDNA ends (Ruberti, F. et al. 1994.
J. Immunol. Methods 173:33); antibody leader sequences (Larrick et
al. 1989 Biochem. Biophys. Res. Commun. 160:1250); or based on
known variable region framework amino acid sequences from the Kabat
(Kabat et al. 1991. Sequences of Proteins of Immunological
Interest. Bethesda, Md.: JS Dep. Health Hum. Serv. 5.sup.th ed.) or
the V-base databases (e.g., Orlandi et al. 1989. Proc. Natl. Acad.
Sci. USA 86:3833; Sblattero et al. 1998. Immunotechnology 3:271; or
Krebber et al. 1997. J. Immunol. Methods 201:35). Constant region
domains can be selected having a particular effector function (or
lacking a particular effector function) or with a particular
modification to reduce immunogenicity. Variable and constant
domains can be cloned, e.g., using the polymerase chain reaction
and primers which are selected to amplify the domain of interest.
PCR amplification methods are described in detail in U.S. Pat. Nos.
4,683,195; 4,683,202; 4,800,159; 4,965,188; and in, e.g., "PCR
Protocols: A Guide to Methods and Applications" Innis et al. eds.,
Academic Press, San Diego, Calif. (1990); Ho et al. 1989. Gene
77:51; Horton et al. 1993. Methods Enzymol. 217:270).
[0123] Alternatively, V domains can be obtained from libraries of V
gene sequences from an animal of choice. Libraries expressing
random combinations of domains, e.g., VH and VL domains, can be
screened with a desired antigen to identify elements which have
desired binding characteristics. Methods of such screening are well
known in the art. For example, antibody gene repertoires can be
cloned into a .lamda. bacteriophage expression vector (Huse, W D et
al. 1989. Science 2476:1275). In addition, cells (Boder and
Wittrup. 1997. Nat. Biotechnol. 15:553; Daugtherty, P. et al. 2000.
J. Immunol. Methods. 243:211; Francisco et al. 1994. Proc. Natl.
Acad. Sci. USA 90:10444; Georgiou et al. 1997. Nature Biotechnology
15:29) or viruses (e.g., Hoogenboom, H R. 1998 Immunotechnology 4:1
Winter et al. 1994. Annu. Rev. Immunol. 12:433; Griffiths, A D.
1998. Curr. Opin. Biotechnol. 9:102) expressing antibodies on their
surface can be screened. Ribosomal display can also be used to
screen antibody libraries (Hanes J., et al. 1998. Proc. Natl. Acad.
Sci. USA 95:14130; Hanes, J. and Pluckthun. 1999. Curr. Top.
Microbial. Immunol. 243:107; He, M. and Taussig. 1997. Nucleic
Acids Research 25:5132).
[0124] Preferred libraries for screening are human V gene
libraries. VL and VH domains from a non-human source may also be
used. In one embodiment, such non-human V domains can be altered to
reduce their immunogenicity using art recognized techniques.
[0125] Libraries can be naive, from immunized subjects, or
semi-synthetic (Hoogenboom, H. R. and Winter, 1992. J. Mol. Biol.
227:381; Griffiths, A D, et al. EMBO J. 13:3245; de Kruif, J. et
al. 1995. J. Mol. Biol. 248:97; Barbas, C. F., et al. 1992. Proc
Natl. Acad. Sci. USA 89:4457).
[0126] In addition, the sequences of many antibody V and C domains
are known and such domains can be synthesized using methods well
known in the art. In one embodiment, mutations can be made to
immunoglobulin domains to create a library of nucleic acid
molecules having greater heterogeneity (Thompson, J., et al. 1996.
J. Mol. Biol. 256:77; Lamminmaki, U. et al. 1999. J. Mol. Biol.
291:589; Caldwell, R. C. and Joyce G F. 1992. PCR Methods Appl.
2:28; Caldwell R C and Joyce G F. 1994. PCR Methods Appl. 3:S136.
Standard screening procedures can be used to select high affinity
variants. In another embodiment, changes to VH and VL sequences can
be made to increase or decrease antibody avidity, e.g., using
information obtained from crystal structures using techniques known
in the art.
[0127] Antigen recognition sites or entire variable regions may be
derived from one or more parental antibodies. The parental
antibodies can include naturally occurring antibodies or antibody
fragments, antibodies or antibody fragments adapted from naturally
occurring antibodies, antibodies constructed de novo using
sequences of antibodies or antibody fragments known to be specific
for GITR. Sequences that may be derived from parental antibodies
include heavy and/or light chain variable regions and/or CDRs,
framework regions or other portions thereof.
[0128] In one embodiment, the GITR binding molecule is a humanized
antibody. To make humanized antibodies, animals are immunized with
the desired antigen, the corresponding antibodies are isolated, and
the portion of the variable region sequences responsible for
specific antigen binding is removed. The animal-derived antigen
binding regions are then cloned into the appropriate position of
human antibody genes in which the antigen binding regions have been
deleted. See, e.g. Jones, P. et al. (1986), Nature 321, 522-525 or
Tempest et al. (1991) Biotechnology 9, 266-273. Also, transgenic
mice, or other mammals, may be used to express humanized
antibodies. Such humanization may be partial or complete. Humanized
antibodies minimize the use of heterologous (inter-species)
sequences in human antibodies, and are less likely to elicit immune
responses in the treated subject.
[0129] In one embodiment, a binding molecule of the invention
comprises or consists of an antigen binding fragment of an
antibody. The term "antigen-binding fragment" refers to a
polypeptide fragment of an immunoglobulin or antibody that binds
antigen or competes with intact antibody (i.e., with the intact
antibody from which they were derived) for antigen binding (i.e.,
specific binding). As used herein, the term "fragment" of an
antibody molecule includes antigen-binding fragments of antibodies,
for example, an antibody light chain (VL), an antibody heavy chain
(VH), a single chain antibody (scFv), a F(ab')2 fragment, a Fab
fragment, an Fd fragment, an Fv fragment, and a single domain
antibody fragment (DAb). Fragments can be obtained, e.g., via
chemical or enzymatic treatment of an intact or complete antibody
or antibody chain or by recombinant means.
[0130] In one embodiment, a binding molecule of the invention is an
engineered or modified antibody. Engineered farms of antibodies
include, for example, minibodies, diabodies, diabodies fused to CH3
molecules, tetravalent antibodies, intradiabodies (e.g., Jendreyko
et al. 2003. J. Biol. Chem. 278:47813), bispecific antibodies,
fusion proteins (e.g., antibody cytokine fusion proteins) or,
bispecific antibodies. Other immunoglobulins (Ig) and certain
variants thereof are described, for example in U.S. Pat. No.
4,745,055; EP 256,654; Faulkner et al., Nature 298:286 (1982); EP
120,694; EP 125,023; Morrison, J. Immun. 123:793 (1979); Kohler et
al., Proc. Natl. Acad. Sci, USA 77:2197 (1980); Raso et al., Cancer
Res. 41:2073 (1981); Morrison et al., Ann. Rev. Immunol. 2:239
(1984); Morrison, Science 229:1202 (1985); Morrison et al., Proc.
Natl. Acad. Sci. USA 81:6851 (1984); EP 255,694; EP 266,663; and WO
88/03559. Reassorted immunoglobulin chains also are known. See, for
example, U.S. Pat. No. 4,444,878; WO 88/03565; and EP 68,763 and
references cited therein.
[0131] In one embodiment, the modified antibodies of the invention
are minibodies. Minibodies are dimeric molecules made up of two
polypeptide chains each comprising an ScFv molecule (a single
polypeptide comprising one or more antigen binding sites, e.g., a
VL domain linked by a flexible linker to a VH domain fused to a CH3
domain via a connecting peptide.
[0132] ScFv molecules can be constructed in a VH-linker-VL
orientation or VL-linker-VH orientation.
[0133] The flexible hinge that links the VL and VH domains that
make up the antigen binding site preferably comprises from about 10
to about 50 amino acid residues. An exemplary connecting peptide
for this purpose is (Gly4Ser)3 (Huston et al. 1988. Proc. Natl.
Acad. Sci. USA 85:5879). Other connecting peptides are known in the
art.
[0134] Methods of making single chain antibodies are well known in
the art, e.g., Ho et al. 1989. Gene 77:51; Bird et al. 1988 Science
242:423; Pantoliano et al. 1991. Biochemistry 30:10117; Milenic et
al. 1991. Cancer Research 51:6363; Takkinen et al. 1991. Protein
Engineering 4:837.
[0135] Minibodies can be made by constructing an ScFv component and
connecting peptide-CH3 component using methods described in the art
(see, e.g., U.S. Pat. No. 5,837,821 or WO 94/09817A1). These
components can be isolated from separate plasmids as restriction
fragments and then ligated and recloned into an appropriate vector.
Appropriate assembly can be verified by restriction digestion and
DNA sequence analysis.
[0136] Diabodies are similar to scFv molecules, but usually have a
short (less than 10 and preferably 1-5) amino acid residue linker
connecting both V-domains, such that the VL and VH domains on the
same polypeptide chain can not interact. Instead, the VL and VH
domain of one polypeptide chain interact with the VH and VL domain
(respectively) on a second polypeptide chain (WO 02/02781). In one
embodiment, a binding molecule of the invention is a diabody fused
to at least one heavy chain portion. In a preferred embodiment, a
binding molecule of the invention is a diabody fused to a CH3
domain.
[0137] Other forms of modified antibodies are also within the scope
of the instant invention (e.g., WO 02/02781 A1; U.S. Pat. Nos.
5,959,083; 6,476,198 B1; US 2002/0103345 A1; WO 00/06605; Byrn et
al. 1990. Nature, 344:667-70; Chamow and Ashkenazi. 1996. Trends
Biotechnol. 14:52).
[0138] In one embodiment, a GITR binding molecule of the invention
is modified to alter one or more glycosylation sites or modified by
one or more other amino acid substitutions that do not alter one or
more glycosylation sites. For example, because the amino acid
sequence Asn-X-(Ser/Thr) is a putative consensus sequence for a
glycosylation site which may affect the production of the binding
molecule, a conservative substitution of a glutamine (Gln) for an
asparagine (Asn) may be made.
[0139] In one embodiment, a binding molecule of the invention
comprises an immunoglobulin constant region. It is known in the art
that the constant region mediates several effector functions. For
example, binding of the C1 component of complement to binding
molecules activates the complement system. Activation of complement
is important in the opsonisation and lysis of cell pathogens. The
activation of complement also stimulates the inflammatory response
and may also be involved in autoimmune hypersensitivity. Further,
binding molecules bind to cells via the Fc region, with a Fc
receptor site on the binding molecule Fc region binding to a Fc
receptor (FcR) on a cell. There are a number of Fc receptors which
are specific for different classes of binding molecule, including
IgG (gamma receptors), IgE (epsilon receptors), IgA (alpha
receptors) and IgM (mu receptors). Binding of binding molecule to
Fc receptors on cell surfaces triggers a number of important and
diverse biological responses including engulfment and destruction
of binding molecule-coated particles, clearance of immune
complexes, lysis of binding molecule-coated target cells by killer
cells (called antibody-dependent cell-mediated cytotoxicity, or
ADCC), release of inflammatory mediators, placental transfer and
control of immunoglobulin production.
[0140] In one embodiment, effector functions may be eliminated or
reduced by, for example, using a constant region of an IgG4 binding
molecule, which is thought to be unable to deplete target cells, or
making Fc variants, wherein residues in the Fc region critical for
effector function(s) are mutated using techniques known in the art,
for example, U.S. Pat. No. 5,585,097. For example, the deletion or
inactivation (through point mutations or other means) of a constant
region domain may reduce Fc receptor binding of the circulating
modified binding molecule thereby increasing tumor localization.
Additionally, amino acid substitutions to remove potential
glycosylation sites on Fc may reduce Fc receptor binding (see,
e.g., Shields, et al. (2001) J Biol Chem 276:6591). In one
embodiment, an N297A substitution is made. In another embodiment, a
L235A substitution and a L237A is made. In yet another embodiment,
a L234A substitution and a L235A substitution is made. In another
embodiment, a E233P substitution is made. In another embodiment, a
L234V substitution is made. In another embodiment, a L235A
substitution is made. In another embodiment, C236 is deleted. In
another embodiment, a P238A substitution is made. In another
embodiment, a D265A substitution is made. In another embodiment, a
N297A substitution is made. In another embodiment, a A327Q
substitution is made. In another embodiment, a P329A substitution
is made. The above recited amino acid positions are based on the EU
numbering system (see, e.g., Kabat, et al. (1991) Sequence of
Proteins of Immunological Interest, 5.sup.th edition, United States
Public Health Service, National Institutes of Health,
Bethesda).
[0141] In other cases it may be that constant region modifications
consistent with the instant invention moderate complement binding
and/or reduce the serum half life. Yet other modifications of the
constant region may be used to modify disulfide linkages or
oligosaccharide moieties that allow for enhanced localization due
to increased antigen specificity or binding molecule flexibility.
More generally, those skilled in the art will realize that binding
molecules modified as described herein may exert a number of subtle
effects that may or may not be readily appreciated. However the
resulting physiological profile, bioavailability and other
biochemical effects of the modifications, such as tumor
localization, biodistribution and serum half-life, may easily be
measured and quantified using well know immunological techniques
without undue experimentation.
[0142] In one embodiment, a binding molecule of the invention can
be derivatized or linked to another functional molecule (e.g.,
another peptide or protein). Accordingly, a binding molecule of the
invention include derivatized and otherwise modified forms of the
GITR binding molecules described herein, including immunoadhesion
molecules. For example, a binding molecule of the invention can be
functionally linked (by chemical coupling, genetic fusion,
noncovalent association or otherwise) to one or more other
molecular entities, such as another binding molecule (e.g., an scFv
antibody, a bispecific antibody or a diabody), a detectable agent,
a chemotherapeutic agent (e.g., as described herein), a
pharmaceutical agent, and/or a protein or peptide that can mediate
association of the binding molecule with another molecule (such as
a streptavidin core region or a polyhistidine tag).
[0143] In one embodiment, a binding molecule of the invention is
modified with polyethylene glycol. "PEGylation" increases residence
time and reduces immunogenicity in vivo. For example, Knauf et al.,
J. Biol. Chem., 263: 15064 15070 (1988) reported a study of the
pharmacodynamic behavior in rats of various polyoxylated glycerol
and polyethylene glycol modified species of interleukin-2. Delgado
et al., Br. J. Cancer, 73: 175 182 (1996), Kitarnura et al., Cancer
Res., 51: 4310 4315 (1991), Kitamura et al., Biochem. Biophys. Res.
Comm., 171: 1387 1394 (1990), and. Pedley et al., Br. J. Cancer,
70: 1126 1130 (1994) reported studies characterizing blood
clearance and tissue uptake of certain anti-tumor antigen
antibodies or antibody fragments derivatized with low molecular
weight (5 kD) PEG. Zapata et al., FASEB J. 9: A1479 (1995) reported
that low molecular weight (5 or 10 kD) PEG attached to a sulfhydryl
group in the hinge region of a Fab' fragment reduced clearance
compared to the parental Fab' molecule.
[0144] One type of derivatized binding molecule is produced by
crosslinking two or more binding molecules (of the same type or of
different types, e.g., to create bispecific antibodies). Suitable
crosslinkers include those that are heterobifunctional, having two
distinctly reactive groups separated by an appropriate spacer
(e.g., m-maleimidobenzoyl-N-hydroxysuccinimide ester) or
homobifunctional (e.g., disuccinimidyl suberate). Such linkers are
available from Pierce Chemical Company, Rockford, Ill.
[0145] A binding molecule of the invention can be prepared by
recombinant expression of immunoglobulin light and heavy chain
genes in a host cell. To express a binding molecule recombinantly,
a host cell is transfected with one or more recombinant expression
vectors carrying DNA fragments encoding the immunoglobulin light
and heavy chains of the binding molecule such that the light and
heavy chains are expressed in the host cell and, preferably,
secreted into the medium in which the host cells are cultured, from
which medium a binding molecule can be recovered. Standard
recombinant DNA methodologies are used to obtain antibody heavy and
light chain genes, incorporate these genes into recombinant
expression vectors, and introduce the vectors into host cells, such
as those described in Sambrook, Fritsch and Maniatis (eds),
Molecular Cloning; A Laboratory Manual, Second Edition, Cold Spring
Harbor, N.Y., (1989), Ausubel, F. M. et al. (eds.) Current
Protocols in Molecular Biology, Greene Publishing Associates,
(1989) and in U.S. Pat. No. 4,816,397 by Boss, et al.
[0146] To express a binding molecule of the invention, DNAs
encoding partial or full-length light and heavy chains may be
inserted into expression vector(s) such that the genes are
operatively linked to transcriptional and translational control
sequences using methods well known in the art. In this context, the
term "operatively linked" means that a binding molecule gene is
ligated into a vector such that transcriptional and translational
control sequences within the vector serve their intended function
of regulating the transcription and translation of the binding
molecule gene. In one embodiment, the expression vector and
expression control sequences are chosen to be compatible with the
expression host cell used. The binding molecule light chain gene
and the binding molecule heavy chain gene may be inserted into
separate vector or, more typically, both genes are inserted into
the same expression vector. The binding molecule genes may be
inserted into the expression vector by standard methods (e.g.,
ligation of complementary restriction sites on the binding molecule
gene fragment and vector, or blunt end ligation if no restriction
sites are present). Prior to insertion of the binding molecule
light or heavy chain sequences, the expression vector may already
carry binding molecule constant region sequences. For example, one
approach to converting VH and VL sequences to full-length binding
molecule genes is to insert them into expression vectors already
encoding heavy chain constant and light chain constant regions,
respectively, such that the VH segment is operatively linked to the
CH segment(s) within the vector and the VL segment is operatively
linked to the CL segment within the vector. Additionally or
alternatively, the recombinant expression vector can encode a
signal peptide that facilitates secretion of the binding molecule
chain from a host cell. The binding molecule chain gene can be
cloned into the vector such that the signal peptide is linked
in-frame to the amino terminus of the binding molecule chain gene.
The signal peptide can be an immunoglobulin signal peptide or a
heterologous signal peptide (i.e., a signal peptide from a
non-immunoglobulin protein).
[0147] In addition to the binding molecule chain genes, the
recombinant expression vectors of the invention carry regulatory
sequences that control the expression of the binding molecule chain
genes in a host cell. The term "regulatory sequence" includes
promoters, enhancers and other expression control elements (e.g.,
polyadenylation signals) that control the transcription or
translation of the binding molecule chain genes. Such regulatory
sequences are described, for example, in Goeddel; Gene Expression
Technology: Methods in Enzymology 185, Academic Press, San Diego,
Calif. (1990). It will be appreciated by those skilled in the art
that the design of the expression vector, including the selection
of regulatory sequences may depend on such factors as the choice of
the host cell to be transformed, the level of expression of protein
desired, etc. Preferred regulatory sequences for mammalian host
cell expression include viral elements that direct high levels of
protein expression in mammalian cells, such as promoters and/or
enhancers derived from cytomegalovirus (CMV) (such as the CMV
promoter/enhancer), Simian Virus 40 (SV40) (such as the SV40
promoter/enhancer), adenovirus, (e.g., the adenovirus major late
promoter (AdMLP) and polyoma. For further description of viral
regulatory elements, and sequences thereof, see e.g., U.S. Pat. No.
5,168,062 by Stinski, U.S. Pat. No. 4,510,245 by Bell et al. and
U.S. Pat. No. 4,968,615 by Schaffner, et al.
[0148] In addition to the binding molecule chain genes and
regulatory sequences, the recombinant expression vectors of the
invention may carry additional sequences, such as sequences that
regulate replication of the vector in host cells (e.g., origins of
replication) and selectable marker genes. The selectable marker
gene facilitates selection of host cells into which the vector has
been introduced (see e.g., U.S. Pat. Nos. 4,399,216, 4,634,665 and
5,179,017, all by Axel et al). For example, typically the
selectable marker gene confers resistance to drugs, such as G418,
hygromycin or methotrexate, on a host cell into which the vector
has been introduced. Preferred selectable marker genes include the
dihydrofolate reductase (DHFR) gene (for use in dhfr.sup.- host
cells with methotrexate selection/amplification) and the neo gene
(for G418 selection).
[0149] For expression of the light and heavy chains, the expression
vector(s) encoding the binding molecule heavy and light chains is
transfected into a host cell by standard techniques. The various
forms of the term "transfection" are intended to encompass a wide
variety of techniques commonly used for the introduction of
exogenous DNA into a prokaryotic or eukaryotic host cell, e.g.,
electroporation, calcium-phosphate precipitation, DEAE-dextran
transfection and the like. It is possible to express a binding
molecule of the invention in either prokaryotic or eukaryotic host
cells, expression of binding molecules in eukaryotic cells, and
most preferably mammalian host cells, is the most preferred because
such eukaryotic cells, and in particular mammalian cells, are more
likely than prokaryotic cells to assemble and secrete a properly
folded and immunologically active binding molecule.
[0150] Commonly, expression vectors contain selection markers
(e.g., ampicillin-resistance, hygromycin-resistance, tetracycline
resistance or neomycin resistance) to permit detection of those
cells transformed with the desired DNA sequences (see, e.g.,
Itakura et al., U.S. Pat. No. 4,704,362).
[0151] E. coli is one prokaryotic host particularly useful for
cloning the polynucleotides (e.g., DNA sequences) of the present
invention. Other microbial hosts suitable for use include bacilli,
such as Bacillus subtilus, and other enterobacteriaceae, such as
Salmonella, Serratia, and various Pseudomonas species. In these
prokaryotic hosts, one can also make expression vectors, which will
typically contain expression control sequences compatible with the
host cell (e.g., an origin of replication). In addition, any number
of a variety of well-known promoters will be present, such as the
lactose promoter system, a tryptophan (trp) promoter system, a
beta-lactamase promoter system, or a promoter system from phage
lambda. The promoters will typically control expression, optionally
with an operator sequence, and have ribosome binding site sequences
and the like, for initiating and completing transcription and
translation.
[0152] Other microbes, such as yeast, are also useful for
expression. Saccharomyces is a preferred yeast host, with suitable
vectors having expression control sequences (e.g., promoters), an
origin of replication, termination sequences and the like as
desired. Typical promoters include 3-phosphoglycerate kinase and
other glycolytic enzymes. Inducible yeast promoters include, among
others, promoters from alcohol dehydrogenase, isocytochrome C, and
enzymes responsible for maltose and galactose utilization.
[0153] In addition to microorganisms, mammalian tissue cell culture
may also be used to express and produce the polypeptides of the
present invention (e.g., polynucleotides encoding binding
molecules). See Winnacker, From Genes to Clones, VCH Publishers,
N.Y., N.Y. (1987). Eukaryotic cells are actually preferred, because
a number of suitable host cell lines capable of secreting
heterologous proteins (e.g., intact binding molecules) have been
developed in the art, and include CHO cell lines, various Cos cell
lines, HeLa cells, myeloma cell lines, or transformed B-cells or
hybridomas. Preferably, the cells are nonhuman. Expression vectors
for these cells can include expression control sequences, such as
an origin of replication, a promoter, and an enhancer (Queen et
al., Immunol. Rev. 89:49 (1986)), and necessary processing
information sites, such as ribosome binding sites, RNA splice
sites, polyadenylation sites, and transcriptional terminator
sequences. Preferred expression control sequences are promoters
derived from immunoglobulin genes, SV40, adenovirus, bovine
papilloma virus, cytomegalovirus and the like. See Co et al., J.
Immunol. 148:1149 (1992).
[0154] Alternatively, binding molecule-coding sequences can be
incorporated in transgenes for introduction into the genome of a
transgenic animal and subsequent expression in the milk of the
transgenic animal (see, e.g., Deboer et al., U.S. Pat. No.
5,741,957, Rosen, U.S. Pat. No. 5,304,489, and Meade et al., U.S.
Pat. No. 5,849,992). Suitable transgenes include coding sequences
for light and/or heavy chains in operable linkage with a promoter
and enhancer from a mammary gland specific gene, such as casein or
beta lactoglobulin.
[0155] Preferred mammalian host cells for expressing the
recombinant binding molecules of the invention include Chinese
Hamster Ovary (CHO cells) (including dhfr-CHO cells, described in
Urlaub and Chasin, (1980) Proc. Natl. Acad. Sci. USA 77:4216-4220,
used with a DHFR selectable marker, e.g., as described in R. J.
Kaufman and P. A. Sharp (1982) Mol. Biol. 159:601-621), NS0 myeloma
cells, COS cells and SP2 cells. When recombinant expression vectors
encoding binding molecule genes are introduced into mammalian host
cells, binding molecules are produced by culturing the host cells
for a period of time sufficient to allow for expression of the
binding molecule in the host cells or, more preferably, secretion
of the binding molecule into the culture medium in which the host
cells are grown. Binding molecules can be recovered from the
culture medium using standard protein purification methods.
[0156] The vectors containing the polynucleotide sequences of
interest (e.g., the binding molecule heavy and light chain encoding
sequences and expression control sequences) can be transferred into
the host cell by well-known methods, which vary depending on the
type of cellular host. For example, calcium chloride transfection
is commonly utilized for prokaryotic cells, whereas calcium
phosphate treatment, electroporation, lipofection, biolistics or
viral-based transfection may be used for other cellular hosts. (See
generally Sambrook et al., Molecular Cloning: A Laboratory Manual
(Cold Spring Harbor Press, 2nd ed., 1989) (incorporated by
reference in its entirety for all purposes). Other methods used to
transform mammalian cells include the use of polybrene, protoplast
fusion, liposomes, electroporation, and microinjection (see
generally, Sambrook et al., supra). For production of transgenic
animals, transgenes can be microinjected into fertilized oocytes,
or can be incorporated into the genome of embryonic stem cells, and
the nuclei of such cells transferred into enucleated oocytes.
[0157] When heavy and light chains are cloned on separate
expression vectors, the vectors are co-transfected to obtain
expression and assembly of intact immunoglobulins. Once expressed,
the whole binding molecules, their dimers, individual light and
heavy chains, or other immunoglobulin forms of the present
invention can be purified according to standard procedures of the
art, including ammonium sulfate precipitation, affinity columns,
column chromatography, HPLC purification, gel electrophoresis and
the like (see generally Scopes, Protein Purification
(Springer-Verlag, N.Y., (1982)). Substantially pure binding
molecules of at least about 90 to 95% homogeneity are preferred,
and 98 to 99% or more homogeneity most preferred, for
pharmaceutical uses.
[0158] Host cells can also be used to produce portions of intact
binding molecules, such as Fab fragments or scFv molecules. It will
be understood that variations on the above procedure are within the
scope of the present invention. For example, it may be desirable to
transfect a host cell with DNA encoding either the light chain or
the heavy chain (but not both) of a binding molecule of this
invention. Recombinant DNA technology may also be used to remove
some or all of the DNA encoding either or both of the light and
heavy chains that is not necessary for binding to GITR. The
molecules expressed from such truncated DNA molecules are also
encompassed by a binding molecule of the invention. In addition,
bifunctional binding molecules may be produced in which one heavy
and one light chain are a binding molecule of the invention and the
other heavy and light chain are specific for an antigen other than
GITR by crosslinking a binding molecule of the invention to a
second binding molecule by standard chemical crosslinking
methods.
III. Additional Agents
[0159] In one embodiment, an additional agent for use in the
combination therapies of the invention is a chemotherapeutic
agent.
[0160] Chemotherapeutic agents generally belong to various classes
including, for example:
[0161] 1. Topoisomerase II inhibitors (cytotoxic antibiotics), such
as the antracyclines/anthracenediones, e.g., doxorubicin,
epirubicin, idarubicin and nemorubicin, the anthraquinones, e.g.,
mitoxantrone and losoxantrone, and the podophillotoxines, e.g.,
etoposide and teniposide;
[0162] 2. Agents that affect microtubule formation (mitotic
inhibitors), such as plant alkaloids (e.g., a compound belonging to
a family of alkaline, nitrogen-containing molecules derived from
plants that are biologically active and cytotoxic), e.g., taxanes,
e.g., paclitaxel and docetaxel, and the vinka alkaloids, e.g.,
vinblastine, vincristine, and vinorelbine, and derivatives of
podophyllotoxin.
[0163] 3. Alkylating agents, such as nitrogen mustards,
ethyleneimine compounds, alkyl sulphonates and other compounds with
an alkylating action such as nitrosoureas, dacarbazine,
cyclophosphamide, ifosfamide and melphalan;
[0164] 4. Antimetabolites (nucleoside inhibitors), for example,
folates, e.g., folic acid, fluropyrimidines, purine or pyrimidine
analogues such as 5-fluorouracil, capecitabine, gemcitabine,
methotrexate and edatrexate;
[0165] 5. Topoisomerase I inhibitors, such as topotecan,
irinotecan, and 9-nitrocamptothecin, and camptothecin derivatives;
and
[0166] 6. Platinum compounds/complexes, such as cisplatin,
oxaliplatin, and carbopaltin;
[0167] Exemplary chemotherapeutic agents for use in the methods of
the invention include, but are not limited to, amifostine (ethyol),
cisplatin, dacarbazine (DTIC), dactinomycin, mechlorethamine
(nitrogen mustard), streptozocin, cyclophosphamide, carmustine
(BCNU), lomustine (CCNU), doxorubicin (adriamycin), doxorubicin
lipo (doxil), gemcitabine (gemzar), daunorubicin, daunorubicin lipo
(daunoxome), procarbazine, mitomycin, cytarabine, etoposide,
methotrexate, 5-fluorouracil (5-FU), vinblastine, vincristine,
bleomycin, paclitaxel (taxol), docetaxel (taxotere), aldesleukin,
asparaginase, busulfan, carboplatin, cladribine, camptothecin,
CPT-11, 10-hydroxy-7-ethyl-camptothecin (SN38), dacarbazine, S-I
capecitabine, ftorafur, 5'deoxyflurouridine, UFT, eniluracil,
deoxycytidine, 5-azacytosine, 5-azadeoxycytosine, allopurinol,
2-chloro adenosine, trimetrexate, aminopterin,
methylene-10-deazaaminopterin (MDAM), oxaplatin, picoplatin,
tetraplatin, satraplatin, platinum-DACH, ormaplatin, CI-973,
JM-216, and analogs thereof, epirubicin, etoposide phosphate,
9-aminocamptothecin, 10,11-methylenedioxycamptothecin, karenitecin,
9-nitrocamptothecin, TAS 103, vindesine, L-phenylalanine mustard,
ifosphamidemefosphamide, perfosfamide, trophosphamide carmustine,
semustine, epothilones A-E, tomudex, 6-mercaptopurine,
6-thioguanine, amsacrine, etoposide phosphate, karenitecin,
acyclovir, valacyclovir, ganciclovir, amantadine, rimantadine,
lamivudine, zidovudine, bevacizumab, trastuzumab, rituximab,
5-Fluorouracil, Capecitabine, Pentostatin, Trimetrexate,
Cladribine, floxuridine, fludarabine, hydroxyurea, ifosfamide,
idarubicin, mesna, irinotecan, mitoxantrone, topotecan, leuprolide,
megestrol, melphalan, mercaptopurine, plicamycin, mitotane,
pegaspargase, pentostatin, pipobroman, plicamaycim, streptozocin,
tamoxifen, teniposide, testolactone, thioguanine, thiotepa, uracil
mustard, vinorelbine, chlorambucil, cisplatin, doxorubicin,
paclitaxel (taxol) and bleomycin, and combinations thereof which
are readily apparent to one of skill in the art based on the
appropriate standard of care for a particular tumor or cancer.
[0168] In one embodiment, a chemotherapeutic agent for use in the
combination therapies of the invention is selected from the group
consisting of Gemzar, 5-FU, Vincristine, Vinblastine, Adriamycin,
Cisplatin, Taxol, Thalidomide, Velcade, methotrexate, cytarabine,
fludarabine, hyroxyurea, danorubracin, etopside, mitoxantrone,
chlorambucil, cyclophosphamide, melphelan, thiotepa, bleomycin,
dacarbazine, L-asparaginase, and procarbazine.
[0169] In one embodiment, a chemotherapeutic agent is a
topoisomerase II inhibitor. In another embodiment, a
chemotherapeutic agent is an agent that affects microtubule
formation. In another embodiment, a chemotherapeutic agent is an
alkylating agent. In another embodiment, a chemotherapeutic agent
is a topoisomerase I inhibitor. In another embodiment, a
chemotherapeutic agent is a platinum compound/complex. In another
embodiment, a chemotherapeutic agent is a hormone, hormonal
analogue, and/or hormonal complex. In another embodiment, a
chemotherapeutic agent is an enzyme, protein, peptide, polyclonal
andor monoclonal antibody. In one embodiment, the chemotherapeutic
agent for use in the methods of the invention is an
antimetabolite.
[0170] The term "antimetabolite" refers to a substance which is
structurally similar to a critical natural intermediate
(metabolite) in a biochemical pathway leading to DNA or RNA
synthesis which is used by the host in that pathway, but acts to
inhibit the completion of that pathway (i.e., synthesis of DNA or
RNA). More specifically, antimetabolites typically function by (1)
competing with metabolites for the catalytic or regulatory site of
a key enzyme in DNA or RNA synthesis, or (2) substitute for a
metabolite that is normally incorporated into DNA or RNA, and
thereby producing a DNA or RNA that cannot support replication.
Major categories of antimetabolites include (1) folic acid analogs,
which are inhibitors of dihydrofolate reductase (DHFR); (2) purine
analogs, which mimic the natural purines (adenine or guanine) but
are structurally different so they competitively or irreversibly
inhibit nuclear processing of DNA or RNA; and (3) pyrimidine
analogs, which mimic the natural pyrimidines (cytosine, thymidine,
and uracil), but are structurally different so they competitively
or irreversibly inhibit nuclear processing of DNA or RNA.
Non-limiting examples of antimetabolites of this invention are
5-Fluorouracil, Floxuradine, Thioguanine, Cytarabine, Fludarabine,
6-Mercaptopurine, Methotrexate, Gemcitabine, Capecitabine,
Pentostatin, Trimetrexate, and Cladribine.
[0171] In one embodiment, the antimetabolite is the nucleoside
analog gemcitabine. In another embodiment, the antimetabolite is
the nucleoside analog fluorouracil.
[0172] As used herein, an "agent that affects microtubule
formation" or "mitotic inhibitor" is an agent that disrupts
microtubule polymerization. Mitotic inhibitors work by interfering
with and halting mitosis (usually during the M phase of the cell
cycle), so that the cell will no longer divide. In one embodiment,
an agent that affects microtubule formation is paclitaxel
(Taxol.RTM.).
[0173] As used herein, an "alkylating agent" is an agent that
cross-links guanine nucleobases in DNA making the strands unable to
uncoil and separate. As this is necessary in DNA replication, the
cells can no longer divide in one embodiment, an alkylating agent
is cyclophosphamide, also known as cytophosphane. Cyclophosphamide
is a prodrug.
[0174] In another embodiment, an additional agent for use in the
combination therapies of the invention is a biologic agent.
[0175] Biological agents (also called biologics) are the products
of a biological system, e.g., an organism, cell, or recombinant
system. Examples of such biologic agents include nucleic acid
molecules (e.g., antisense nucleic acid molecules), interferons,
interleukins, colony-stimulating factors, antibodies, e.g.,
monoclonal antibodies, anti-angiogenesis agents, and cytokines.
Exemplary biologic agents are discussed in more detail below and
generally belong to various classes including, for example
[0176] 1. Hormones, hormonal analogues, and hormonal complexes,
e.g., estrogens and estrogen analogs, progesterone, progesterone
analogs and progestins, androgens, adrenocorticosteroids,
antiestrogens, antiandrogens, antitestosterones, adrenal steroid
inhibitors, and anti-leuteinizing hormones; and
[0177] 2. Enzymes, proteins, peptides, polyclonal and/or monoclonal
antibodies, such as interleukins, interferons, colony stimulating
factor, etc.
[0178] In one embodiment, the biologic is an interfereon.
Interferons (IFN) are a type biologic agent that naturally occurs
in the body. Interferons are also produced in the laboratory and
given to cancer patients in biological therapy. They have been
shown to improve the way a cancer patient's immune system acts
against cancer cells. Interferons may work directly on cancer cells
to slow their growth, or they may cause cancer cells to change into
cells with more normal behavior. Some interferons may also
stimulate natural killer cells (NK) cells, T cells, and
macrophages--types of white blood cells in the bloodstream that
help to fight cancer cells.
[0179] In one embodiment, the biologic is an interleukin.
Interleukins (IL) stimulate the growth and activity of many immune
cells. They are proteins (cytokines and chemokines) that occur
naturally in the body, but can also be made in the laboratory. Some
interleukins stimulate the growth and activity of immune cells,
such as lymphocytes, which work to destroy cancer cells.
[0180] In another embodiment, the biologic is a colony-stimulating
factor. Colony-stimulating factors (CSFs) are proteins given to
patients to encourage stem cells within the bone marrow to produce
more blood cells. The body constantly needs new white blood cells,
red blood cells, and platelets, especially when cancer is present.
CSFs are given, along with chemotherapy, to help boost the immune
system. When cancer patients receive chemotherapy, the bone
marrow's ability to produce new blood cells is suppressed, making
patients more prone to developing infections. Parts of the immune
system cannot function without blood cells, thus colony-stimulating
factors encourage the bone marrow stem cells to produce white blood
cells, platelets, and red blood cells. With proper cell production,
other cancer treatments can continue enabling patients to safely
receive higher doses of chemotherapy.
[0181] In another embodiment, the biologic is an antibody.
Antibodies, e.g., monoclonal antibodies, are agents, produced in
the laboratory, that bind to cancer cells. When cancer-destroying
agents are introduced into the body, they seek out the antibodies
and kill the cancer cells. Monoclonal antibody agents do not
destroy healthy cells. Monoclonal antibodies achieve their
therapeutic effect through various mechanisms. They can have direct
effects in producing apoptosis or programmed cell death. They can
block growth factor receptors, effectively arresting proliferation
of tumor cells. In cells that express monoclonal antibodies, they
can bring about anti-idiotype antibody formation.
[0182] Examples of antibodies which may be used in the combination
treatment of the invention include anti-CD20 antibodies, such as,
but not limited to, cetuximab, Tositumomab, rituximab, and
Ibritumomab. Anti-HER2 antibodies may also be used in combination
with an anti-GITR antibody for the treatment of cancer. In one
embodiment, the anti-HER2 antibody is Trastuzumab (Herceptin).
Other examples of antibodies which may be used in combination with
an anti-GITR antibody for the treatment of cancer include anti-CD52
antibodies (e.g., Alelmtuzumab), anti-CD-22 antibodies (e.g.,
Epratuzamab), and anti-CD33 antibodies (e.g., Gemtuzumab
ozogamicin). Anti-VEGF antibodies may also be used in combination
with an anti-GITR antibody for the treatment of cancer. In one
embodiment, the anti-VEGF antibody is bevacizumab. In other
embodiments, the biologic agent is an antibody which is an
anti-EGFR antibody e.g., cetuximab. Another example is the
anti-glycoprotein 17-1A antibody edrecolomab.
[0183] In another embodiment, the biologic is a cytokine. Cytokine
therapy uses proteins (cytokines) to help a subject's immune system
recognize and destroy those cells that are cancerous. Cytokines are
produced naturally in the body by the immune system, but can also
be produced in the laboratory. This therapy is used with advanced
melanoma and with adjuvant therapy (therapy given after or in
addition to the primary cancer treatment). Cytokine therapy reaches
all parts of the body to kill cancer cells and prevent tumors from
growing.
[0184] In another embodiment, the biologic is a fusion protein.
Fusion proteins may also be used. For example, recombinant human
Apo2L/TRAIL (Genentech) may be used in a combination therapy.
Apo2/TRAIL, is the first dual pro-apoptotic receptor agonist
designed to activate both pro-apoptotic receptors DR4 and DR5,
which are involved in the regulation of apoptosis (programmed cell
death).
[0185] In one embodiment, the biologic is an antisense nucleic acid
molecule. Antisense nucleic acid molecules may also be used in the
methods of the invention. As used herein, an "antisense" nucleic
acid comprises a nucleotide sequence which is complementary to a
"sense" nucleic acid encoding a protein, e.g., complementary to the
coding strand of a double-stranded cDNA molecule, complementary to
an mRNA sequence or complementary to the coding strand of a gene.
Accordingly, an antisense nucleic acid can hydrogen bond to a sense
nucleic acid.
[0186] In one embodiment, a biologic agent is an siRNA molecule,
e.g., of a molecule that enhances angiogenesis, e.g., bFGF, VEGF
and EGFR. In one embodiment, a biologic agent that inhibits
angiogenesis mediates RNAi. RNA interference (RNAi) is a
post-transcriptional, targeted gene-silencing technique that uses
double-stranded RNA (dsRNA) to degrade messenger RNA (mRNA)
containing the same sequence as the dsRNA (Sharp, P. A. and Zamore,
P. D. 287, 2431-2432 (2000); Zamore, P. D., et al. Cell 101, 25-33
(2000). Tuschl, T. et al. Genes Dev. 13, 3191-3197 (1999); Cottrell
T R, and Doering T L. 2003. Trends Microbial. 11:37-43; Bushman F.
2003. Mol Therapy. 7:9-10; McManus M T and Sharp P A. 2002. Nat Rev
Genet. 3:737-47). The process occurs when an endogenous
ribonuclease cleaves the longer dsRNA into shorter, e.g., 21- or
22-nucleotide-long RNAs, termed small interfering RNAs or siRNAs.
The smaller RNA segments then mediate the degradation of the target
mRNA. Kits for synthesis of RNAi are commercially available from,
e.g. New England Biolabs or Ambion. In one embodiment one or more
of the chemistries described herein for use in antisense RNA can be
employed in molecules that mediate RNAi.
[0187] The use of antisense nucleic acids to downregulate the
expression of a particular protein in a cell is well known in the
art (see e.g., Weintraub, H, et al., Antisense RNA as a molecular
tool for genetic analysis, Reviews--Trends in Genetics, Vol. 1(1)
1986; Askari, F. K. and McDonnell, W. M. (1996) N. Eng. J. Med.
334:316-318; Bennett, M. R. and Schwartz, S. M. (1995) Circulation
92:1981-1993; Mercola, D. and Cohen, J. S. (1995) Cancer Gene Ther.
2:47-59; Rossi, J. J. (1995) Br. Med. Bull. 51:217-225; Wagner, R.
W. (1994) Nature 372:333-335). An antisense nucleic acid molecule
comprises a nucleotide sequence that is complementary to the coding
strand of another nucleic acid molecule (e.g., an mRNA sequence)
and accordingly is capable of hydrogen bonding to the coding strand
of the other nucleic acid molecule. Antisense sequences
complementary to a sequence of an mRNA can be complementary to a
sequence found in the coding region of the mRNA, the 5.degree. or
3.degree. untranslated region of the mRNA or a region bridging the
coding region and an untranslated region (e.g., at the junction of
the 5' untranslated region and the coding region). Furthermore, an
antisense nucleic acid can be complementary in sequence to a
regulatory region of the gene encoding the mRNA, for instance a
transcription initiation sequence or regulatory element.
Preferably, an antisense nucleic acid is designed so as to be
complementary to a region preceding or spanning the initiation
codon on the coding strand .COPYRGT.r in the 3' untranslated region
of an mRNA.
[0188] Given the coding strand sequences of a molecule that
enhances angiogenesis, antisense nucleic acids of the invention can
be designed according to the rules of Watson and Crick base
pairing. The antisense nucleic acid molecule can be complementary
to the entire coding region of the mRNA, but more preferably is an
oligonucleotide which is antisense to only a portion of the coding
or noncoding region of the mRNA. For example, the antisense
oligonucleotide can be complementary to the region surrounding the
translation start site of the mRNA. An antisense oligonucleotide
can be, for example, about 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50
nucleotides in length. An antisense nucleic acid of the invention
can be constructed using chemical synthesis and enzymatic ligation
reactions using procedures known in the art. For example, an
antisense nucleic acid (e.g., an antisense oligonucleotide) can be
chemically synthesized using naturally occurring nucleotides or
variously modified nucleotides designed to increase the biological
stability of the molecules or to increase the physical stability of
the duplex formed between the antisense and sense nucleic acids,
e.g., phosphorothioate derivatives and acridine substituted
nucleotides can be used. Examples of modified nucleotides which can
be used to generate the antisense nucleic acid include
5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-iodouracil,
hypoxanthine, xantine, 4-acetylcytosine, 5-(carboxyhydroxylmethyl)
uracil, 5-carboxymethylaminomethyl-2-thiouridine,
5-carboxymethylaminomethyluracil, dihydrouracil,
beta-D-galactosylqueosine, inosine, N6-isopentenyladenine,
1-methylguanine, 1-methylinosine, 2,2-dimethylguanine,
2-methyladenine, 2-methylguanine, 3-methylcytosine,
5-methylcytosine, N6-adenine, 7-methylguanine,
5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil,
beta-D-mannosylqueosine, 5'-methoxycarboxymethyluracil,
5-methoxyuracil, 2-methylthio-N6-isopentenyladenine,
uracil-5-oxyacetic acid (v), wybutoxosine, pseudouracil, queosine,
2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil,
5-methyluracil, uracil-5-oxyacetic acid methylester,
uracil-5-oxyacetic acid (v), 5-methyl-2-thiouracil,
3-(3-amino-3-N-2-carboxypropyl) uracil, (acp3)w, and
2,6-diaminopurine. To inhibit expression in cells, one or more
antisense oligonucleotides can be used. Alternatively, the
antisense nucleic acid can be produced biologically using an
expression vector into which a nucleic acid has been subcloned in
an antisense orientation (i.e., RNA transcribed from the inserted
nucleic acid will be of an antisense orientation to a target
nucleic acid of interest, described further in the following
subsection).
[0189] In yet another embodiment, the antisense nucleic acid
molecule of the invention is an .alpha.-anomeric nucleic acid
molecule. An .alpha.-anomeric nucleic acid molecule forms specific
double-stranded hybrids with complementary RNA in which, contrary
to the usual .beta.-units, the strands run parallel to each other
(Gaultier et al. (1987) Nucleic Acids. Res. 15:6625-6641). The
antisense nucleic acid molecule can also comprise a
2'-o-methylribonucleotide (Inoue et al. (1987) Nucleic Acids Res.
15:6131-6148) or a chimeric RNA-DNA analogue (Inoue et al. (1987)
FEBS Lett. 215:327-330).
[0190] In another embodiment, an antisense nucleic acid of the
invention is a compound that mediates RNAi. RNA interfering agents
include, but are not limited to, nucleic acid molecules including
RNA molecules which are homologous to the target gene or genomic
sequence, "short interfering RNA" (siRNA), "short hairpin" or
"small hairpin RNA" (shRNA), and small molecules which interfere
with or inhibit expression of a target gene by RNA interference
(RNAi). RNA interference is a post-transcriptional, targeted
gene-silencing technique that uses double-stranded RNA (dsRNA) to
degrade messenger RNA (mRNA) containing the same sequence as the
dsRNA (Sharp, P. A. and Zamore, P. D. 287, 2431-2432 (2000);
Zamore, P. D., et al. Cell 101, 25-33 (2000). Tuschl, T. et al.
Genes Dev. 13, 3191-3197 (1999)). The process occurs when an
endogenous ribonuclease cleaves the longer dsRNA into shorter, 21-
or 22-nucleotide-long RNAs, termed small interfering RNAs or
siRNAs. The smaller RNA segments then mediate the degradation of
the target mRNA. Kits for synthesis of RNAi are commercially
available from, e.g. New England Biolabs and Ambion. In one
embodiment one or more of the chemistries described above for use
in antisense RNA can be employed.
[0191] Nucleic acid molecules encoding molecules that, e.g.,
inhibit angiogenesis, may be introduced into the subject in a form
suitable for expression of the encoded protein in the cells of the
subject may also be used in the methods of the invention. Exemplary
molecules that inhibit angiogenesis include, but are not limited
to, TSP-1, TSP-2, IFN-.alpha., IFN-.gamma., angiostatin, endostsin,
tumastatin, canstatin, VEGI, PEDF, vasohibin, and the 16 kDa
fragment of prolactin 2-Methoxyestradiol (see, Kerbel (2004) J.
Clin Invest 114:884, for review).
[0192] For example, a full length or partial cDNA sequence is
cloned into a recombinant expression vector and the vector is
transfected into a cell using standard molecular biology
techniques. The cDNA can be obtained, for example, by amplification
using the polymerase chain reaction (PCR) or by screening an
appropriate cDNA library. The nucleotide sequences of the cDNA can
be used for the design of PCR primers that allow for amplification
of a cDNA by standard PCR methods or for the design of a
hybridization probe that can be used to screen a cDNA library using
standard hybridization methods. Following isolation or
amplification of the cDNA, the DNA fragment is introduced into a
suitable expression vector.
[0193] Exemplary biologic agents for use in the methods of the
invention include, but are not limited to, gefitinib (Iressa),
anastrazole, diethylstilbesterol, estradiol, premarin, raloxifene,
progesterone, norethynodrel, esthisterone, dimesthisterone,
megestrol acetate, medroxyprogesterone acetate, hydroxyprogesterone
caproate, norethisterone, methyltestosterone, testosterone,
dexamthasone, prednisone, Cortisol, solumedrol, tamoxifen,
fulvestrant, toremifene, aminoglutethimide, testolactone,
droloxifene, anastrozole, bicalutamide, flutamide, nilutamide,
goserelin, flutamide, leuprolide, triptorelin, aminoglutethimide,
mitotane, goserelin, cetuximab, erlotinib, imatinib, Tositumomab,
Alemtuzumab, Trastuzumab, Gemtuzumab, Rituximab, Ibritumomab
tiuxetan, Bevacizumab, Denileukin diftitox, Daclizumab, interferon
alpha, interferon beta, anti-4-1BB, anti-4-1BBL, anti-CD40,
anti-CD154, anti-OX40, anti-OX40L, anti-CD28, anti-CD80, anti-CD86,
anti-CD70, anti-CD27, anti-HVEM, anti-LIGHT, anti-GITRL,
anti-CTLA-4, soluble OX40L, soluble 4-1BBL, soluble CD154, soluble
GITRL, soluble LIGHT, soluble CD70, soluble CD80, soluble CD86,
soluble CTLA4-1g, GVAX.RTM., and combinations thereof which are
readily apparent to one of skill in the art based on the
appropriate standard of care for a particular tumor or cancer. The
soluble forms of agents may be made as, for example fusion
proteins, by operatively linking the agent with, for example, Ig-Fc
region.
[0194] It should be noted that more than one additional agent,
e.g., 1, 2, 3, 4, 5, may be administered in combination with a GITR
binding molecule. For example, in one embodiment two
chemotherapeutic agents may be administered in combination with a
GITR binding molecule. In another embodiment, a chemotherapeutic
agent, a biologic agent, and a GITR binding molecule may be
administered.
[0195] Various forms of the biologic agents may be used. These
include, without limitation, such forms as proform molecules,
uncharged molecules, molecular complexes, salts, ethers, esters,
amides, and the like, which are biologically activated when
implanted, injected or otherwise inserted into the tumor.
IV Therapeutic Methods
[0196] The present invention further provides methods of
administering to the subject a combination therapy of the
invention.
[0197] As set forth above, the methods of the present invention,
i.e., the use of a GITR binding molecule in combination with a
second agent that is useful in treating cancer, may be used to
treat a malignancy or cancer in a subject. Exemplary cancers
include: pancreatic cancer, melanoma, breast cancer, lung cancer,
bronchial cancer, colorectal cancer, prostate cancer, stomach
cancer, ovarian cancer, urinary bladder cancer, brain or central
nervous system cancer, peripheral nervous system cancer, esophageal
cancer, cervical cancer, uterine or endometrial cancer, cancer of
the oral cavity or pharynx, liver cancer, kidney cancer, testicular
cancer, biliary tract cancer, small bowel or appendix cancer,
salivary gland cancer, thyroid gland cancer, adrenal gland cancer,
osteosarcoma, chondrosarcoma, and cancer of hematological
tissues.
[0198] In one embodiment, the methods of the invention may be used
to treat melanoma. In another embodiment, the methods of the
invention may be used to treat solid tumors, e.g., a carcinoma.
Examples of solid tumors that can be treated by compounds of the
present invention, include but are not limited to breast,
testicular, lung, ovary, uterine, cervical, pancreatic, non small
cell lung (NSCLC), colon, as well as prostate, gastric, skin,
stomach, esophagus and bladder cancer. In one embodiment, a solid
tumor is an adenocarcinoma, e.g., of the colon. In one embodiment
of the invention, a solid tumor is a colon tumor. In another
embodiment of the invention, a solid tumor is selected from the
group consisting of a colon tumor, a lung tumor, a breast tumor, a
stomach tumor, a prostate tumor, a cervical tumor, a vaginal tumor,
and a pancreatic tumor.
[0199] In another embodiment, the tumor is selected from the group
consisting of Stage I, Stage II, Stage III, and Stage IV tumors.
The stage of a tumor is readily determined by one of skill in the
art using art recognized methods of staging, such as the size of
the tumor, the number of lymph nodes or other tissues to which the
tumor has metastasized, microscopic analyses, histological
analyses, etc.
[0200] In one embodiment of the invention, the subject combination
therapies are used to treat established tumors, e.g., tumors of
sufficient size such that nutrients can no longer permeate to the
center of the tumor from the subject's vasculature by osmosis and
therefore the tumor requires its own vascular supply to receive
nutrients, i.e, a vascularized tumor. In another embodiment, the
subject combination therapies are used to treat, e.g., inhibit the
establishment of secondary tumor, e.g., metastasis, and/or reduce
the size of a tumor, e.g., an established tumor, and/or a secondary
tumor, e.g., a metastasis. In yet another embodiment, the subject
combination therapies are used to prevent the establishment of
secondary tumors, e.g., metastasis.
[0201] In one embodiment, a combination therapy is used to treat a
tumor having dimensions of at least about 1 mm.times.1 mm. In
another embodiment of the invention, a combination therapy is used
to treat a tumor that is at least about 0.5 mm.times.0.5 mm. In
other embodiments of the invention the tumor has a volume of at
least about 100 mm.sup.3. In one embodiment, a combination therapy
of the invention is used to treat a tumor that is large enough to
be found by palpation or by imaging techniques well known in the
art, such as MRI, ultrasound, or CAT scan.
[0202] In certain embodiments of the invention, the subject methods
result in an inhibition of tumor size more than about 10%, more
than about 20%, more than about 30%, more than about 35%, more than
about 42%, more than about 43%, more than about 44%, more than
about 45%, more than about 46%, more than about 47%, more than
about 48%, more than about 49%, more than about 50%, more than
about 51%, more than about 52%, more than about 53%, more than
about 54%, more than about 55%, more than about 56%, more than
about 57%, more than about 58%, more than about 59%, more than
about 60%, more than about 65%, more than about 70%, more than
about 75%, more than about 80%, more than about 85%, more than
about 90%, more than about 95%, or more than about 100%. In one
embodiment, the administration of a GITR binding molecule, or an
antigen-binding fragment thereof, and at least one chemotherapeutic
agent results in a % T/C of about 42% or greater.
[0203] In one embodiment, the combination therapies of the
invention have a synergistic effect. A "synergistic effect" of two
compounds is one in which the effect of the combination of the two
agents is greater than the sum of their individual effects and is
statistically different from the controls and the single drugs. In
another embodiment, the combination therapies of the invention have
an additive effect. An "additive effect" of two compounds is one in
which the effect of the combination of the two agents is the sum of
their individual effects and is statistically different from either
the controls and/or the single drugs.
[0204] The GITR binding molecule can be administered in a
convenient manner such as by injection (subcutaneous, intravenous,
etc.), oral administration, inhalation, transdermal application, or
rectal administration. Depending on the route of administration,
the active compound can be coated in a material to protect the
compound from the action of enzymes, acids and other natural
conditions which may inactivate the compound. For example, to
administer the agent by other than parenteral administration, it
may be desirable to coat, or co-administer the agent with, a
material to prevent its inactivation.
[0205] In general, the at least one additional agent to be
administered in combination with the GITR binding molecule will be
administered via the route by which it is routinely administered
when used alone. It will be understood that the GITR binding
molecule and the at least one additional agent need not be
administered via the same route.
[0206] A combination therapy of the present invention can be
administered by a variety of methods known in the art, although for
many therapeutic applications, the preferred route/mode of
administration is intravenous injection or infusion. As will be
appreciated by the skilled artisan, the route and/or mode of
administration will vary depending upon the desired results. In
certain embodiments, the active compound may be prepared with a
carrier that will protect the compound against rapid release, such
as a controlled release formulation, including implants,
transdermal patches, and microencapsulated delivery systems.
Biodegradable, biocompatible polymers can be used, such as ethylene
vinyl acetate, polyanhydrides, polyglycolic acid, collagen,
polyorthoesters, and polylactic acid. Many methods for the
preparation of such formulations are patented or generally known to
those skilled in the art. See, e.g., Sustained and Controlled
Release Drug Delivery Systems, J. R. Robinson, ed., Marcel Dekker,
Inc., New York, 1978.
[0207] In certain embodiments, a binding molecule of the invention
may be orally administered, for example, with an inert diluent or
an assimilable edible carrier. The compound (and other ingredients,
if desired) may also be enclosed in a hard or soft shell gelatin
capsule, compressed into tablets, or incorporated directly into the
subject's diet. For oral therapeutic administration, the compounds
may be incorporated with excipients and used in the form of
ingestible tablets, buccal tablets, troches, capsules, elixirs,
suspensions, syrups, wafers, and the like. To administer a compound
of the invention by other than parenteral administration, it may be
necessary to coat the compound with, or co-administer the compound
with, a material to prevent its inactivation.
[0208] In certain embodiments, the method comprises parenterally
administering an effective amount of a GITR binding molecule and a
second agent to a subject. In one embodiment, the method comprises
intraarterial administration of a GITR binding molecule and at
least one chemotherapeutic agent to a subject. In other
embodiments, the method comprises administering an effective amount
of a GITR binding molecule and at least one chemotherapeutic agent
directly to the arterial blood supply of a tumor in a subject. In
one embodiment, the methods comprise administering an effective
amount of a GITR binding molecule and at least one chemotherapeutic
agent directly to the arterial blood supply of the cancerous tumor
using a catheter. In embodiments where a catheter is used to
administer a GITR binding molecule and at least one
chemotherapeutic agent, the insertion of the catheter may be guided
or observed by fluoroscopy or other method known in the art by
which catheter insertion may be observed and/or guided. In another
embodiment, the method comprises chemoembolization. For example a
chemoembolization method may comprise blocking a vessel feeding the
cancerous tumor with a composition comprised of a resin-like
material mixed with an oil base (e.g., polyvinyl alcohol in
Ethiodol) and one or more chemotherapeutic agents. In still other
embodiments, the method comprises systemic administration of a GITR
binding molecule and at least one chemotherapeutic agent to a
subject.
[0209] In general, chemoembolization or direct intraarterial or
intravenous injection therapy utilizing pharmaceutical compositions
of the present invention is typically performed in a similar
manner, regardless of the site. Briefly, angiography (a road map of
the blood vessels), or more specifically in certain embodiments,
arteriography, of the area to be embolized may be first performed
by injecting radiopaque contrast through a catheter inserted into
an artery or vein (depending on the site to be embolized or
injected) as an X-ray is taken. The catheter may be inserted either
percutaneously or by surgery. The blood vessel may be then
embolized by refluxing pharmaceutical compositions of the present
invention through the catheter, until flow is observed to cease.
Occlusion may be confirmed by repeating the angiogram. In
embodiments where direct injection is used, the blood vessel is
then infused with a pharmaceutical composition of the invention in
the desired dose.
[0210] Embolization therapy generally results in the distribution
of compositions containing inhibitors throughout the interstices of
the tumor or vascular mass to be treated. The physical bulk of the
embolic particles clogging the arterial lumen results in the
occlusion of the blood supply. In addition to this effect, the
presence of an anti-angiogenic factor(s) prevents the formation of
new blood vessels to supply the tumor or vascular mass, enhancing
the devitalizing effect of cutting off the blood supply. Direct
intrarterial, intravenous or injection administration generally
results in distribution of compositions containing inhibitors
throughout the interstices of the tumor or vascular mass to be
treated as well. However, the blood supply is not generally
expected to become occluded with this method.
[0211] In one aspect of the present invention, primary and
secondary tumors may be treated utilizing embolization or direct
intraarterial or intravenous injection therapy. Briefly, a catheter
is inserted via the femoral or brachial artery and advanced into
the, e.g., hepatic artery, by steering it through the arterial
system under fluoroscopic guidance. The catheter is advanced into
the hepatic arterial tree as far as necessary to allow complete
blockage of the blood vessels supplying the tumor(s), while sparing
as many of the arterial branches supplying normal structures as
possible. Ideally this will be a segmental branch of the hepatic
artery, but it could be that the entire hepatic artery distal to
the origin of the gastroduodenal artery, or even multiple separate
arteries, will need to be blocked depending on the extent of tumor
and its individual blood supply. Once the desired catheter position
is achieved, the artery is embolized by injecting compositions (as
described above) through the arterial catheter until flow in the
artery to be blocked ceases, preferably even after observation for
5 minutes. Occlusion of the artery may be confirmed by injecting
radio-opaque contrast through the catheter and demonstrating by
fluoroscopy or X-ray film that the vessel which previously filled
with contrast no longer does so. In embodiments where direct
injection is used, the artery is infused by injecting compositions
(as described above) through the arterial catheter in a desired
dose. The same procedure may be repeated with each feeding artery
to be occluded.
[0212] With respect to dosing, it is to be noted that dosage
amounts, number of cycles administered, and the sequence of
administration may vary with the severity of the condition to be
alleviated. It is to be further understood that for any particular
subject, specific dosage regimens may be adjusted over time
according to the individual need and the professional judgment of
the person administering or supervising the administration of the
compositions. Typically, dosing will be determined using techniques
known to one skilled in the art. The selected dosage level will
depend upon a variety of factors including the activity of the
agent, or the ester, salt or amide thereof, the route of
administration, the time of administration, the rate of excretion
or metabolism of the particular compound being employed, the
duration of the treatment, other drugs, compounds and/or materials
used in combination with the particular compound employed, the age,
sex, weight, condition, general health, disease state, the ability
of the binding molecule to elicit a desired response in the
individual, and prior medical history of the patient being treated,
and like factors well known in the medical arts.
[0213] Dosage regimens may be adjusted to provide the optimum
desired response. For example, a single bolus may be administered,
several divided doses may be administered over time or the dose may
be proportionally reduced or increased as indicated by the
exigencies of the therapeutic situation. In one embodiment, one or
more of the agents to be administered may be formulated as a
parenteral composition in dosage unit form for ease of
administration and uniformity of dosage. Dosage unit form as used
herein refers to physically discrete units suited as unitary
dosages for the mammalian subjects to be treated; each unit
containing a predetermined quantity of active compound calculated
to produce the desired therapeutic effect in association with the
required pharmaceutical carrier. The specification for the dosage
unit forms of the invention are dictated by and directly dependent
on (a) the unique characteristics of the active compound and the
particular therapeutic or prophylactic effect to be achieved, and
(b) the limitations inherent in the art of compounding such an
active compound for the treatment of sensitivity in
individuals.
[0214] A physician or veterinarian having ordinary skill in the art
can readily determine and prescribe the effective amount of each of
the agents of the subject combination therapy. For example, the
physician or veterinarian could administer at least one additional
agent at the dose at which it would be administered to the subject
if it were to be administered alone, or as part of a combination
therapy that does not employ a GITR binding molecule. Such art
recognized dosing protocols can be determined by the skilled
artisan without undue experimentation.
[0215] The combined use of a GITR binding molecule and at least one
chemotherapeutic agent as described herein, may reduce the required
dosage for any individual agent. Accordingly, in one embodiment,
the dose of at least one additional agent may be lower than that
required in order to achieve the desired therapeutic effect were
the agent to be administered alone.
[0216] With respect to GITR binding molecules, one of ordinary
skill in the art would also readily be able to determine an optimal
dose. For example, an anti-GITR antibody could be administered at a
dose of between about 50 mg/kg and about 0.05 mg/kg. In one
embodiment, an anti-GITR antibody could be administered at a dose
of between about 40 mg/kg and about 0.1 mg/kg. In another
embodiment, an anti-GITR antibody could be administered at a dose
of between about 30 mg/kg and about 0.5 mg/kg. In still another
embodiment, an anti-GITR antibody could be administered at a dose
of between about 20 mg/kg and about 1 mg/kg. Ranges intermediate to
the above recited values are also intended to be part of this
invention. In yet another embodiment, an anti-GITR antibody could
be administered at a dose of between about 10 mg/kg and about 5
mg/kg. For example, exemplary doses include: about 0.06, about
0.07, about 0.08, about 0.09, about 0.1, about 0.2, about 0.3,
about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9,
about 1, about 1.5, about 2, about 2.5, about 3, about 3.5, about
4, about 4.5, about 5, about 10, about 20, about 30, or about 40
mg/kg. It is noted that the dosages and dosage ranges set forth
herein are exemplary only and are not intended to limit the scope
or practice of the claimed composition.
[0217] Data obtained from cell culture assays and animal studies
may be used in formulating a range of dosage for use in humans by
for example, determining the dose at which no adverse effects occur
in, for example, a mouse, and determining the human equivalent
dosage (see, e.g., www.fda.gov/cber/gdlns/dose.htm, the contents of
which are incorporated herein by reference). The dosage of any
supplement, or alternatively of any components therein, lies
preferably within a range of circulating concentrations that
include the ED50 (median effective dose) with little or no
toxicity. The dosage may vary within this range depending upon the
dosage form employed and the route of administration utilized. For
agents of the present invention, the therapeutically effective dose
may be estimated initially from cell culture assays. A dose may be
formulated in animal models to achieve a circulating plasma
concentration range that includes the IC50 (i.e., the concentration
of the test compound which achieves a half-maximal inhibition of
symptoms) as determined in cell culture. Such information may be
used to more accurately determine useful doses in humans. Levels in
plasma may be measured, for example, by high performance liquid
chromatography.
[0218] Alternatively, the dosage of the subject invention may be
determined by reference to the plasma concentrations of the
composition. For example, the maximum plasma concentration (Cmax)
and the area under the plasma concentration-time curve from time 0
to infinity (AUC (0-4)) may be used. Dosages for the present
invention include those that produce the above values for Cmax and
AUC (0-4) and other dosages resulting in larger or smaller values
for those parameters.
[0219] The precise time of administration and amount of any
particular compound that will yield the most effective treatment in
a given patient will depend upon the activity, pharmacokinetics,
and bioavailability of a particular compound, physiological
condition of the patient (including age, sex, disease type and
stage, general physical condition, responsiveness to a given dosage
and type of medication), route of administration, and the like. The
guidelines presented herein may be used to optimize the treatment,
e.g., determining the optimum time and/or amount of administration,
which will require no more than routine experimentation consisting
of monitoring the subject and adjusting the dosage and/or
timing.
[0220] In one embodiment, the at least one non-GITR binding agent
of the combination therapy is administered to a subject prior to
administration of the GITR binding molecule. The non-GITR binding
molecule may be administered once or more than once to the patient.
In cases of repeat administration, the non-GITR binding molecule
may be administered daily, on alternative days, weekly, monthly, or
according to another schedule. An exemplary treatment entails
administration in multiple dosages over a prolonged period, for
example, of at least six months.
[0221] Similarly, a GITR binding molecule of the invention may be
administered once or more than once to a subject. In cases of
repeat administration, the GITR binding molecule may be
administered daily, on alternative days, weekly, monthly, or
according to another schedule. An exemplary treatment entails
administration in multiple dosages over a prolonged period, for
example, of at least six months.
[0222] In instances when the non-GITR binding molecule is
administered prior to or after the administration of the GITR
binding molecule, intervals between administration of the agents
can be, e.g., minutes, hours, days, weeks, or months.
[0223] A combination therapy of the invention comprising a GITR
binding molecule and at least one additional agent may optionally
include administration of additional agents or treatment regimes,
e.g., surgery, radiation therapy, that are effective in treating
cancer. Preferred additional agents are those which are art
recognized and are routinely administered to treat a particular
disorder.
[0224] While the subject is being treated, the health of the
patient may be monitored by measuring one or more of the relevant
indices at predetermined times, e.g., during a 24-hour period.
Treatment, including supplement, amounts, times of administration
and formulation, may be optimized according to the results of such
monitoring. The patient may be periodically reevaluated to
determine the extent of improvement by measuring the same
parameters, the first such reevaluation typically occurring at the
end of four weeks from the onset of therapy, and subsequent
reevaluations occurring every four to eight weeks during therapy
and then every three months thereafter. Therapy may continue for
several months or even years, with a minimum of one month being a
typical length of therapy for humans. Adjustments to the amount(s)
of agent administered and possibly to the time of administration
may be made based on these reevaluations.
[0225] In one embodiment, the GITR binding molecule and the second
agent are conjugated using methods known in the art.
V Kits of the Invention
[0226] The present invention provides kits and articles of
manufacture for use of the methods of the present invention. The
invention also pertains to packaged pharmaceutical compositions or
kits for administering the GITR binding molecule and a second agent
used in the invention, for the treatment of cancer. In one
embodiment of the invention, the kit or article of manufacture,
comprises a GITR binding molecule, and instructions for
administration for treatment of cancer in combination with at least
one additional agent, e.g., a chemotherapeutic agent. In another
embodiment, the kit comprises a second container comprising at
least one additional agent for use in a combination therapy with
the GITR binding molecule. The instructions may describe how, e.g.,
intravenously, and when, e.g., at week 0 and week 2, the different
doses of GITR binding molecule and at least one chemotherapeutic
agent shall be administered to a subject for treatment.
[0227] The package or kit alternatively can contain the GITR
binding molecule and it can be promoted for use, either within the
package or through accompanying information, for the uses or
treatment of the disorders described herein. The packaged
pharmaceuticals or kits further can include a chemotherapeutic
agent (as described herein) packaged with or co-promoted with
instructions for using the second agent, e.g., a chemotherapeutic
agent, with a first agent, e.g. a GITR binding molecule.
[0228] For example, a kit may comprise a packaging material, one or
more GITR binding molecules and at least one chemotherapeutic agent
as described above and optionally a label or package insert. In
still other embodiments, the invention provides a kit comprising
one or more GITR binding molecules and at least one
chemotherapeutic agent and one or more devices for accomplishing
administration of such compositions. For example, a kit may
comprise a pharmaceutical composition comprising a GITR binding
molecule and catheter for accomplishing direct intraarterial
injection of the composition into a solid tumor. The kits
optionally include accessory components such as a second container
comprising a pharmaceutically-acceptable buffer and instructions
for using the composition.
[0229] This invention is further illustrated by the following
examples, which should not be construed as limiting. The contents
of all references, patents and published patent applications cited
throughout this application, as well as the Figures, are
incorporated herein by reference.
EXAMPLES
Example 1
The Combination of a GITR Binding Molecule and a Nucleoside Analog
Decreases Tumor Burden and Increases Survival Time in an Animal
Model of Colon Carcinoma
[0230] Mice were injected in the flank with 1.times.10.sup.5 CT26
cells and divided into groups. One group of control mice was
untreated. The group of mice receiving Gemzar was treated with 80
mg/kg Gemzar on Day 15. One group of mice received anti-GITR
antibody (2F8) alone at a dose of 0.4 mg (I.P.) on Days 15, 16 and
17. The group of mice receiving Gemzar+2F8 were given 80 mg/kg
Gemzar on Day 15 and 0.4 mg of 2F8 (LP.) on Day 16.
[0231] The size of the tumors and the survival of the mice were
monitored. GraphPad Prism 4 software was used to plot Kaplan-Meir
survival curves and to confirm the median survival times for the
groups. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0232] Tumor burden in mice treated with the combination of Gemzar
and 2F8 was reduced as compared to the tumor burden of mice treated
with vehicle, Gemzar alone, or 2F8 alone (FIG. 1).
[0233] In addition, as shown in FIG. 2, the median survival for the
IgG2a control mice and the mice treated with the GITR binding
molecule alone was 24 days. Median survival was 31 days for the
mice treated with Gemzar alone. All the Gemzar plus 2F8 treated
mice were still alive at day 31 and the tumors were moderate in
size.
[0234] In a second study, mice were injected in the tail vein with
1.times.10.sup.5 CT26 cells and tumors were allowed to establish in
the lung for 10 days. The animals were then divided into groups.
One group of control mice was untreated. The group of mice
receiving Gemzar was treated with 80 mg/kg Gemzar on Day 15. One
group of mice received anti-GITR antibody (2F8) alone at a dose of
0.4 mg (I.P.) on Days 15, 16 and 17. The group of mice receiving
Gemzar+2F8 were given 80 mg/kg Gemzar on Day 15 and 0.4 mg of 2F8
(I.P.) on Day 16. The number of tumors was assessed on day 22.
[0235] As shown in FIG. 3, the number of tumors in mice treated
with the combination of Gemzar and 2F8 was reduced as compared to
the number of tumors in mice treated with vehicle, Gemzar alone, or
2F8 alone.
Example 2
The Combination of a GITR Binding Molecule and an Agent that
Affects Microtubule Formation Decreases Tumor Burden in an Animal
Model of Melanoma
[0236] Mice were injected in the flank with 12.times.10.sup.3 B16
melanoma cells and divided into groups. One group of control mice
was untreated. The group of mice receiving Taxol.RTM. was treated
with 10 mg/kg Taxol.RTM. on Day 20 when tumors were approximately
100 mm.sup.3. One group of mice received anti-GITR antibody (2F8)
alone at a dose of 0.4 mg (I.P.) on Day 21. The group of mice
receiving Taxol.RTM.+2F8 were given 10 mg/kg Taxol.RTM. on Day 20
and 0.4 mg of 2F8 (I.P.) on Day 21.
[0237] The size of the tumors and the survival of the mice were
monitored. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0238] As shown in FIG. 4, the tumor burden in mice treated with
the combination of Taxol.RTM. and 2F8 was reduced as compared to
the tumor burden of mice treated with vehicle, Taxol.RTM. alone, or
2F8 alone.
Example 3
The Combination of a GITR Binding Molecule and an Alkylating Agent
Decreases Tumor Burden in an Animal Model of Colon Carcinoma
[0239] Mice were injected subcutaneously with 1.times.10.sup.5 CT26
cells and divided into groups. One group of control mice was
untreated. The group of mice receiving Cytoxan was treated with 150
mg/kg Cytoxan on Day 13. One group of mice received anti-GITR
antibody (2F8) alone at a dose of 0.4 mg (I.P.) on Day 14. The
group of mice receiving Cytoxan+2F8 were given 150 mg/kg
Cytoxan.RTM. onDay 13 and 0.4 mg of 2F8 (I.P.) on Day 14.
[0240] The size of the tumors and the survival of the mice were
monitored. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0241] As shown in FIG. 5, the tumor burden in mice treated with
the combination of Cytoxan and 2F8 was reduced as compared to the
tumor burden of mice treated with vehicle or Cytoxan alone.
Example 4
An Animal Model of Colon Carcinoma Treated with the Combination of
a GITR Binding Molecule and an Alkylating Agent or a Nucleoside
Analog Develop a Robust Memory Response to CT26 Cells
[0242] Mice treated as above in Examples 1 and 4 that had complete
remission of their tumors were used in studies where they were
injected with 3.times.10.sup.5 CT26 cells IV (4 mice) or 10.sup.6
CT26 cells on their left flank and 10.sup.6 RENCA cells on their
right flank (4 mice). Mice naive to CT26 were used as controls. All
4 combination treated mice rejected the CT26 cell challenge and 2/4
completely rejected the RENCA cells. In the IV study, lungs were
resected 14 days after injection of cells, stained with India ink
and fixed with Fekete's Solution and analyzed for the presence of
tumors; analysis of the lungs of all 4 animals showed no visible
signs of tumors.
Example 5
The Combination of a GITR Binding Molecule and an Antimetabolite
Decreases Tumor Burden in an Animal Model of Colon Carcinoma
[0243] Mice were injected subcutaneously with 1.times.10.sup.5 CT26
cells and divided into groups. One group of control mice was
untreated. The group of mice receiving fluorouracil (5-FU) was
treated with 75 mg/kg 5-FU on Day 10. The group of mice receiving
5-FU+2F8 were given 75 mg/kg 5-FU on Day 10 and 0.4 mg of 2F8
(I.P.) on Day 11.
[0244] The size of the tumors and the survival of the mice were
monitored. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0245] As shown in FIG. 6, the tumor burden in mice treated with
the combination of 5-FU and 2F8 was reduced as compared to the
tumor burden of mice treated with vehicle or 5-FU alone.
Example 6
The Combination of a GITR Binding Molecule and a Cytotoxic
Antibiotic Decreases Tumor Burden in an Animal Model of Colon
Carcinoma
[0246] Mice were injected subcutaneously with 1.times.10.sup.5 CT26
cells and divided into groups. One group of control mice was
untreated. The group of mice receiving doxorubicin (Adriamycin) was
treated with 5 mg/kg doxorubicin on Day 10. The group of mice
receiving doxorubicin+2F8 were given 5 mg/kg doxorubicin on Day 10
and 0.4 mg of 2F8 (I.P.) on Day 11.
[0247] The size of the tumors and the survival of the mice were
monitored. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0248] As shown in FIG. 7, the tumor burden in mice treated with
the combination of doxorubicin and 2F8 was reduced as compared to
the tumor burden of mice treated with vehicle or doxorubicin
alone.
Example 7
The Combination of a GITR Binding Molecule and an Alkylating Agent
Decreases Tumor Burden in an Animal Model of Melanoma
[0249] Mice were injected subcutaneously with 1.times.10.sup.4 B16
melanoma cells and divided into groups. One group of control mice
was untreated. The group of mice receiving Cytoxan was treated with
150 mg/kg Cytoxan on Day 13. One group of mice received anti-GITR
antibody (2F8) alone at a dose of 0.4 mg (I.P.) on Day 14. The
group of mice receiving Cytoxan+2F8 were given 150 mg/kg
Cytoxan.RTM. on Day 13 and 0.4 mg of 2F8 (I.P.) on Day 14.
[0250] The size of the tumors and the survival of the mice were
monitored. Tumors were measured using calipers, and tumor size was
calculated using the formula (L.times.W.sup.2)/2.
[0251] As shown in FIG. 8, the tumor burden in mice treated with
the combination of Cytoxan and 2F8 was reduced as compared to the
tumor burden of mice treated with vehicle or Cytoxan alone.
EQUIVALENTS
[0252] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. Such equivalents are intended to be encompassed by the
following claims.
[0253] All publications and patents mentioned herein, including
those items listed below, are hereby incorporated by reference in
their entirety as if each individual publication or patent was
specifically and individually indicated to be incorporated by
reference.
Sequence CWU 1
1
7112PRTHomo sapiens 1Gly Phe Ser Leu Ser Thr Ser Gly Met Gly Val
Gly1 5 10 216PRTHomo sapiens 2His Ile Trp Trp Asp Asp Asp Lys Tyr
Tyr Asn Pro Ser Leu Lys Ser1 5 10 15 316PRTHomo sapiens 3His Ile
Trp Trp Asp Asp Asp Lys Tyr Tyr Gln Pro Ser Leu Lys Ser1 5 10 15
49PRTHomo sapiens 4Thr Arg Arg Tyr Phe Pro Phe Ala Tyr1 5
511PRTHomo sapiens 5Lys Ala Ser Gln Asn Val Gly Thr Asn Val Ala1 5
10 67PRTHomo sapiens 6Ser Ala Ser Tyr Arg Tyr Ser1 5 79PRTHomo
sapiens 7Gln Gln Tyr Asn Thr Asp Pro Leu Thr1 5
* * * * *
References