U.S. patent application number 11/894766 was filed with the patent office on 2008-04-17 for compounds and methods for the treatment of cancer.
This patent application is currently assigned to The Texas A&M University System. Invention is credited to Hatice Duzkale, Emil J. Freireich, Mingzhang Gao, Hagop Kantarjian, Merida Sotelo-Lerma, Srdan Verstovsek, Ralph A. Zingaro.
Application Number | 20080090793 11/894766 |
Document ID | / |
Family ID | 35414967 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080090793 |
Kind Code |
A1 |
Zingaro; Ralph A. ; et
al. |
April 17, 2008 |
Compounds and methods for the treatment of cancer
Abstract
The present invention provides organic arsenicals. Many of these
compounds have potent in vitro cytotoxic activity against numerous
human tumor cell lines, both of solid and hematological origin, as
well as against malignant blood cells from patients with
leukemia.
Inventors: |
Zingaro; Ralph A.; (College
station, TX) ; Duzkale; Hatice; (Houston, TX)
; Freireich; Emil J.; (Houston, TX) ; Kantarjian;
Hagop; (Bellaire, TX) ; Sotelo-Lerma; Merida;
(Hermosillo, MX) ; Verstovsek; Srdan; (Houston,
TX) ; Gao; Mingzhang; (Indianapolis, IN) |
Correspondence
Address: |
ROPES & GRAY LLP
PATENT DOCKETING 39/41
ONE INTERNATIONAL PLACE
BOSTON
MA
02110-2624
US
|
Assignee: |
The Texas A&M University
System
College Station
TX
Board of Regents, The University of Texas System
Austin
TX
|
Family ID: |
35414967 |
Appl. No.: |
11/894766 |
Filed: |
August 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11252966 |
Oct 17, 2005 |
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11894766 |
Aug 20, 2007 |
|
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PCT/US05/25192 |
Jul 15, 2005 |
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11252966 |
Oct 17, 2005 |
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60588596 |
Jul 16, 2004 |
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Current U.S.
Class: |
514/188 ;
514/504; 546/3; 556/70 |
Current CPC
Class: |
A61P 15/00 20180101;
A61P 17/00 20180101; A61P 7/06 20180101; A61P 1/16 20180101; A61P
7/00 20180101; A61P 25/00 20180101; A61P 35/00 20180101; C07F 9/72
20130101; A61P 35/04 20180101; A61P 11/00 20180101; A61P 1/18
20180101; A61P 13/08 20180101; A61P 13/12 20180101; C07F 9/74
20130101; A61P 1/04 20180101; A61P 19/08 20180101; A61P 35/02
20180101 |
Class at
Publication: |
514/188 ;
514/504; 546/003; 556/070 |
International
Class: |
A61K 31/285 20060101
A61K031/285; A61K 31/555 20060101 A61K031/555; A61P 35/00 20060101
A61P035/00; C07F 9/00 20060101 C07F009/00; C07F 9/80 20060101
C07F009/80 |
Claims
1. A compound having a structure of formula (I) or a
pharmaceutically acceptable salt thereof ##STR16## wherein X is S
or Se; W is O, S, or (R)(R), where each occurrence of R is
independently H or C.sub.1-2alkyl; n is 0 or 1; R.sup.1 and R.sup.2
are each independently C.sub.1-10alkyl; R.sup.3 is --H,
C.sub.1-10alkyl, or C.sub.0-6alkyl-COOR.sup.6; R.sup.3' is H,
amino, cyano, halogen, aryl, aralkyl, heteroaryl, heteroaralkyl,
carboxyl, C.sub.1-10alkyl, C.sub.1-10alkenyl, or C.sub.1-10alkynyl;
R.sup.4 is --OH, --H, --CH.sub.3, amino, --OC(O)C.sub.1-10aralkyl,
--OC(O) C.sub.1-10alkyl, or --OC(O)aryl; and R.sup.5 is --OH,
cyano, C.sub.1-6alkoxy, amino, O--C.sub.1-10alkyl, O-aralkyl,
--OC(O) C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, --OC(O)aryl, or
a glycine substituent; and R.sup.6 is H or C.sub.1-10alkyl.
2-19. (canceled)
20. A compound of claim 1 selected from ##STR17##
21. A compound having a structure of formula (II) or a
pharmaceutically acceptable salt thereof ##STR18## wherein the
melting point of the compound in its crystalline form is greater
than 125.degree. C.
22-28. (canceled)
29. A compound of claim 21, wherein a compound of formula (II) is
substantially free of pyridine hydrochloride.
30. A compound having a structure of formula (IV) or a
pharmaceutically acceptable salt thereof ##STR19## wherein X is S
or Se; W is O, S, or (R)(R), where each occurrence of R is
independently H or a C.sub.1-2alkyl; Z is CH or N; R.sup.1 and
R.sup.2 are independently C.sub.1-10alkyl, preferably R.sup.1 and
R.sup.2 are independently selected from methyl, ethyl, propyl, and
isopropyl; and R.sup.5 is --OH, cyano, C.sub.1-10alkoxy, amino,
O-aralkyl, O-aralkyl, --OC(O) C.sub.1-10aralkyl, --OC(O)
C.sub.1-10alkyl, --OC(O)aryl, or a glycine substituent; R.sup.6 is
H or C.sub.1-10alkyl; R.sup.7 is selected from halogen, --OH,
C.sub.0-6alkyl-COOR.sup.6, C.sub.1-6alkyl, C.sub.1-6alkoxy, amino,
amido, cyano, and nitro; m is an integer from 0 to 4.
31-37. (canceled)
38. A compound of claim 30, selected from ##STR20##
39. A method for treating cancer, comprising administering a
therapeutically effective amount of a compound of any one of claims
1, 21, or 30.
40. The method of claim 39, wherein said cancer comprises a solid
tumor.
41. (canceled)
42. The method of claim 39, wherein said cancer is a hematological
cancer.
43-55. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of PCT
Application No. PCT/US05/25192, filed Jul. 15, 2005, which claims
the benefit of U.S. Provisional Application No. 60/588,596, filed
Jul. 16, 2004. This application is also a continuation-in-part of
U.S. application Ser. No. 11/035,178, filed Jan. 13, 2005, which is
a continuation of U.S. application Ser. No. 10/337,969, filed Jan.
7, 2003 (now U.S. Pat. No. 6,911,471), which claims the benefit of
U.S. Provisional Application No. 60/346,492, filed Jan. 7, 2002,
the specifications of which are hereby incorporated by reference in
their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of
anti-cancer therapy. More particularly, it provides organic arsenic
compounds and methods for their use in treating cancers such as
leukemia and solid tumors.
BACKGROUND OF THE INVENTION
[0003] Despite progress in leukemia therapy, most adult patients
with leukemia still die from disease progression. Arsenic trioxide,
an inorganic compound, has been approved for the treatment of
patients with relapsed or refractory acute promyelocytic leukemia
(APL) and is being evaluated as therapy for other leukemia types.
Preliminary data from China and the recent experience in the U.S.,
however, suggest a role for arsenic trioxide in the other
hematologic cancers as well. Consequently, the activity of arsenic
trioxide as an anti-leukemic agent is currently being investigated
in many types of leukemia. Although the results look favorable in
terms of the response rate of some of the leukemia types that are
being investigated, systemic toxicity of arsenic trioxide is a
problem (Soignet et al., 1999; Wiernik et al., 1999; Geissler et
al., 1999; Rousselot et al., 1999).
[0004] The only organic arsenical (OA) manufactured for human use,
melarsoprol, has been evaluated for antileukemic activity
(WO9924029, EP1002537). Unfortunately, this compound is excessively
toxic to patients with leukemia at concentrations used for the
treatment of trypanosomiasis. Therefore, there is a need to
identify arsenic derivatives that can be used for the treatment of
hematologic malignancies and cancer in general, that have similar
or greater activity and lower toxicity than arsenic trioxide.
SUMMARY OF THE INVENTION
[0005] The present invention provides organic arsenical compounds
with anti-cancer properties. In some embodiments, the present
invention provides compounds having a structure of formula (I) or a
pharmaceutically acceptable salt thereof ##STR1## wherein [0006] X
is S or Se; [0007] W is O, S, or (R)(R), where each occurrence of R
is independently H or C.sub.1-2alkyl; [0008] n is 0 or 1; [0009]
R.sup.1 and R.sup.2 are each independently C.sub.1-10alkyl; [0010]
R.sup.3 is --H, C.sub.1-10alkyl, or C.sub.0-6alkyl-COOR.sup.6;
[0011] R.sup.3' is H, amino, cyano, halogen, aryl, aralkyl,
heteroaryl, heteroaralkyl, carboxyl, C.sub.1-10alkyl,
C.sub.1-10alkenyl, or C.sub.1-10alkynyl, preferably H; [0012]
R.sup.4 is --OH, --H, --CH.sub.3, amino, --OC(O)C.sub.1-10aralkyl,
--OC(O)C.sub.1-10alkyl, or --OC(O)aryl; [0013] R.sup.5 is --OH,
cyano, C.sub.1-10alkoxy, amino, O-aralkyl,
--OC(O)C.sub.1-10aralkyl, --OC(O)C.sub.1-10alkyl, --OC(O)aryl, or a
glycine substituent; and [0014] R.sup.6 is H or
C.sub.1-10alkyl.
[0015] Another aspect of the invention relates to a compound of
formula (II) ##STR2## or a pharmaceutically acceptable salt thereof
associated with pyridine hydrochloride, wherein the melting point
of the compound in its crystalline form is greater than 125.degree.
C.
[0016] In certain embodiments, the organic arsenicals are compounds
having a structure of formula (III) ##STR3## wherein [0017] X is S
or Se, preferably S; [0018] W is O, S, or (R)(R), where each
occurrence of R is independently H or a C.sub.1-2alkyl, preferably
O; [0019] Z is CH or N, preferably N; [0020] R.sup.1 and R.sup.2
are independently C.sub.1-10alkyl, preferably R.sup.1 and R.sup.2
are independently selected from methyl, ethyl, propyl, and
isopropyl; and [0021] R.sup.5 is --OH, cyano, C.sub.1-10alkoxy,
amino, O-aralkyl, O-aralkyl, --OC(O)C.sub.1-10aralkyl,
--OC(O)C.sub.1-10alkyl, --OC(O)aryl, or a glycine substituent,
preferably OH; [0022] R.sup.6 is H or C.sub.1-10alkyl; [0023]
R.sup.7 is selected from halogen, --OH, C.sub.0-6alkyl-COOR.sup.6,
C.sub.1-6alkyl, C.sub.1-6alkoxy, amino, amido, cyano, and nitro;
[0024] m is an integer from 0 to 4, preferably 0.
[0025] Other objects, features, and advantages of the present
invention will become apparent from the following detailed
description. It should be understood, however, that the detailed
description and the specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration
only, since various changes and modifications within the spirit and
scope of the invention will become apparent to those skilled in the
art from this detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0026] The following drawings form part of the present
specification and are included to further demonstrate certain
aspects of the present invention. The invention may be better
understood by reference to one or more of these drawings in
combination with the detailed description of specific embodiments
presented herein.
[0027] FIG. 1 shows the human leukemia cell line NB4 was incubated
for 3 days with indicated concentrations of
S-dimethylarsino-thiosuccinic acid (MER1) or arsenic trioxide.
[0028] FIG. 2 shows the human leukemia cell line AML2 was incubated
for 3 days with indicated concentrations of MER1 or arsenic
trioxide. Cell survival was assessed by the trypan-blue exclusion
method.
[0029] FIG. 3A shown percent growth for human leukemia cell lines
when treated with MER1.
[0030] FIG. 3B shows percent growth for human CNS cell lines when
treated with MER1.
[0031] FIG. 3C shows percent growth for human renal cancer cell
lines when treated with MER1.
[0032] FIG. 3D shows percent growth for human non-small cell lung
cancer cell lines when treated with MER1.
[0033] FIG. 3E shows percent growth for human melanoma cell lines
when treated with MER1.
[0034] FIG. 3F shows percent growth for human prostate cancer cell
lines when treated with MER1.
[0035] FIG. 3G shows percent growth for human colon cancer cell
lines when treated with MER1.
[0036] FIG. 3H shows percent growth for human ovarian cancer cell
lines when treated with MER1.
[0037] FIG. 3I shows percent growth for human breast cancer cell
lines when treated with MER1.
[0038] FIG. 4 shows cell survival of HL60 human leukemia cells that
were incubated for 3 days with indicated concentrations of
S-dimethylarsino-2-thiobenzoic acid (SAL1).
[0039] FIG. 5A shows the percentage growth for human leukemia cell
lines when treated with SAL1.
[0040] FIG. 5B shows the percentage growth for human CNS cancer
cell lines when treated with SAL1.
[0041] FIG. 5C shows the percentage growth for human renal cancer
cell lines when treated with SAL1.
[0042] FIG. 5D shows the percentage growth for human non-small cell
lung cancer cell lines when treated with SAL1.
[0043] FIG. 5E shows the percentage growth for human melanoma cell
lines when treated with SAL1.
[0044] FIG. 5F shows the percentage growth for human prostate
cancer cell lines when treated with SAL1.
[0045] FIG. 5G shows the percentage growth for human colon cancer
cell lines when treated with SAL1.
[0046] FIG. 5H shows the percentage growth for human ovarian cancer
cell lines when treated with SAL1.
[0047] FIG. 5I shows the percentage growth for human breast cancer
cell lines when treated with SAL1.
[0048] FIG. 6 shows cell survival of NB4 cells that were incubated
for 3 days with indicated concentrations of
S-dimethylarsino-glutathione (SGLU1) or arsenic trioxide.
[0049] FIG. 7 shows a five day clonogenic assay was performed using
HL60 cells and SGLU1 or arsenic trioxide.
[0050] FIG. 8A shows the percent growth of human leukemia cell
lines treated with SGLU1.
[0051] FIG. 8B shows the percent growth of human CNS cell lines
treated with SGLU1.
[0052] FIG. 8C shows the percent growth of human renal cancer cell
lines treated with SGLU1.
[0053] FIG. 8D shows the percent growth of human non-small cell
lung cancer cell lines treated with SGLU1.
[0054] FIG. 8E shows the percent growth of human melanoma cell
lines treated with SGLU1.
[0055] FIG. 8F shows the percent growth of human prostate cancer
cell lines treated with SGLU1.
[0056] FIG. 8G shows the percent growth of human colon cancer cell
lines treated with SGLU1.
[0057] FIG. 8H shows the percent growth of human ovarian cancer
cell lines treated with SGLU1.
[0058] FIG. 8I shows the percent growth of human breast cancer cell
lines treated with SGLU1.
[0059] FIG. 9 shows cell survival of mononuclear cells from an
acute myeloid leukemia (AML) patient that were incubated for 3 days
with indicated concentrations of MER1 or arsenic trioxide.
[0060] FIG. 10 shows cell survival of mononuclear cells from AML
patient that were incubated for 4 days with indicated
concentrations of MER1 or arsenic trioxide.
[0061] FIG. 11 shows cell survival of mononuclear cells from an AML
patient that were incubated for 5 days with indicated
concentrations of MER1 or arsenic trioxide.
[0062] FIG. 12 shows cell survival of mononuclear cells from a
chronic myeloid leukemia-blastic phase (CML-BP) patient that were
incubated for 3 days with indicated concentrations of MER1 or
arsenic trioxide.
[0063] FIG. 13 shows cell survival of mononuclear cells from an
acute lymphoblastic leukemia (ALL) patient that were incubated for
4 days with indicated concentrations of MER1 or arsenic
trioxide.
[0064] FIG. 14 shows cell survival of mononuclear cells from a
normal donor that were incubated for 5 days with indicated
concentrations of MER1 or arsenic trioxide.
[0065] FIG. 15 shows an 8-day clonogenic assay was performed using
normal donor cells and MER1 or arsenic trioxide.
[0066] FIG. 16 shows cell survival of mononuclear cells from a
chronic lymphocytic leukemia (CLL) patient that were incubated for
5 days with indicated concentrations of SGLU1 or arsenic
trioxide.
[0067] FIG. 17 shows an 8-day clonogenic assay that was performed
using mononuclear cells from AML patient with SGLU1 or arsenic
trioxide.
[0068] FIG. 18 shows an 8-day clonogenic assay that was performed
using normal donor cells, and SGLU1 or arsenic trioxide.
[0069] FIG. 19 shows stability of MER-1 formulation using trypan
blue assays with HL60 cells and MER-1.
[0070] FIG. 20 shows apoptosis assessed by annexin V assay in HI-60
cells treated with MER1 for 1, 2, or 3 days.
[0071] FIG. 21 shows dead cell number was assessed by the propidium
iodine assay on H1-60 cells treated with MER1 for 1, 2, or 3
days.
[0072] FIG. 22 shows cell survival assessed by trypan-blue
exclusion method in HL60 cells treated with MER1 for 1, 2, or 3
days.
[0073] FIG. 23A shows the annexin V assay of HL-60 cells treated
with MER1, SGU1, or arsenic oxide at 48 hours.
[0074] FIG. 23B shows the caspase assay (phi-phi-lux staining) of
HL-60 cells treated with MER1, SGU1, or arsenic oxide at 48
hours.
[0075] FIG. 23C shows the CMXRos/MT-Green assays of H1-60 cells
treated with MER1, SGU1, or arsenic oxide at 48 hours.
[0076] FIG. 23D shows the annexin V assay of HL-60 cells treated
with MER1, SGU1, or arsenic oxide at 72 hours.
[0077] FIG. 23E shows the caspase assay of HL-60 cells treated with
MER1, SGU1, or arsenic oxide at 72 hours.
[0078] FIG. 23F shows the CMXRos/MT-Green assays of H1-60 cells
treated with MER1, SGU1, or arsenic oxide at 72 hours.
[0079] FIG. 24 shows NB4 cells assayed for the effects of arsenic
trioxide, SGLU1 and MER1 on maturation.
[0080] FIG. 25A shows HL60 cells assayed for the effects of
MER1.
[0081] FIG. 25B shows HL60 cells assayed for the effects of
SGLU1.
[0082] FIG. 25C shows HL60 cells assayed for the effects of arsenic
trioxide.
[0083] FIG. 26A shows a three day MTT assay in U937/9PR cells
treated with arsenic trioxide with and without zinc to analyze the
role of the PML/Rar alpha gene.
[0084] FIG. 26B shows a three day MTT assay in U937/9PR cells
treated with SGLU1 with and without zinc to analyze the role of the
PML/Rar alpha gene.
[0085] FIG. 26C shows a three day MTT assay in U937/9PR cells
treated with MER1 with and without zinc to analyze the role of the
PML/Rar alpha gene.
[0086] FIG. 27A shows the cytotoxicity of arsenic trioxide and
GMZ27 against HL60 cells.
[0087] FIG. 27B shows the effects of ATO and GMZ27 on the colony
growth of cells from AML patients.
[0088] FIG. 28A shows flow cytometry evaluation of apoptosis
induced by STO and GMZ27 in HL60 AML cells by evaluation of annexin
V binding.
[0089] FIG. 28B shows flow cytometry evaluation of apoptosis
induced by STO and GMZ27 in HL60 AML cells by evaluation of
activation of caspase 3.
[0090] FIG. 28C shows flow cytometry evaluation of apoptosis
induced by STO and GMZ27 in HL60 AML cells by evaluation of
mitochondrial membrane potential change.
[0091] FIG. 29 shows the Western blotting analysis of apoptosis
related proteins affected by GMZ27 in HL60 AML cells.
[0092] FIG. 30A shows a 72 hour MTS assay where cells were
pretreated with BSO.
[0093] FIG. 30B shows a 72 hour MTS assay where cells were
pretreated with DTT.
[0094] FIG. 30C shows super-oxide production after pretreatment
with NAC.
[0095] FIG. 31A shows ROS production of ATO and GMZ27 where
super-oxide production was monitored by flow cytometry. Cells were
incubated for 1 hour.
[0096] FIG. 31B shows ROS production of ATO and GMZ27 where
super-oxide production was monitored by flow cytometry. Cells were
incubated for 3 hours.
[0097] FIG. 32 shows the effect of ATO and GMZ27 on the
maturation/differentiation of NB4 APL cells after a 48 hour
incubation period.
[0098] FIG. 33A shows propidium iodine staining of HL60 cells
treated with different doses of GMZ27 for 24 hours.
[0099] FIG. 33B shows propidium iodine staining of HL60 cells
treated with different doses of GMZ27 for 48 hours.
[0100] FIG. 34 shows the effect of ATO and GMZ27 on the colony
growth of primary cells from a normal donor.
DETAILED DESCRIPTION OF THE INVENTION
[0101] The present invention provides a number of organic arsenic
compounds.
[0102] In certain embodiments, the organic arsenicals of the
present invention have a structure of formula (I) or a
pharmaceutically acceptable salt thereof ##STR4## wherein [0103] X
is S or Se, preferably S; [0104] W is O, S, or (R)(R), where each
occurrence of R is independently H or a C.sub.1-2alkyl, preferably
O or (R)(R); [0105] n is 0 or 1, preferably 1; [0106] R.sup.1 and
R.sup.2 are independently C.sub.1-10alkyl, preferably R.sup.1 and
R.sup.2 are independently selected from methyl, ethyl, propyl, and
isopropyl; [0107] R.sup.3 is --H, C.sub.1-10alkyl, or
C.sub.0-6alkyl-COOR.sup.6; [0108] R.sup.3' is H, amino, cyano,
halogen, aryl, aralkyl, heteroaryl, heteroaralkyl, carboxyl,
C.sub.1-10alkyl, C.sub.1-10alkenyl, or C.sub.1-10alkynyl,
preferably H; [0109] R.sup.4 is --OH, --H, --CH.sub.3, amino,
--OC(O)C.sub.1-10aralkyl, --OC(O)C.sub.1-10alkyl, or --OC(O)aryl;
[0110] R.sup.5 is --OH, cyano, C.sub.1-10alkoxy, amino, O-aralkyl,
--OC(O)C.sub.1-10aralkyl, --OC(O)C.sub.1-10alkyl, --OC(O)aryl, or a
glycine substituent; and [0111] R.sup.6 is H or C.sub.1-10alkyl,
preferably H.
[0112] In certain embodiments, W is (R)(R) and each occurrence of R
is independently H or a C.sub.1-2alkyl. In certain such
embodiments, each occurrence of R is H.
[0113] In certain embodiments, R.sup.3 is --H or
C.sub.0-6alkyl-COOR.sup.6. In certain such embodiments, R.sup.3 is
selected from --COOR.sup.6, --CH.sub.2COOR.sup.6,
--CH.sub.2CH.sub.2COOR.sup.6, --CH(CH.sub.3)COOR.sup.6,
--CH(CH.sub.2CH.sub.3)COOR.sup.6, or
--CH.sub.2CH.sub.2CH.sub.2COOR.sup.6, wherein R.sup.6 is
C.sub.1-10alkyl.
[0114] In certain embodiments, R.sup.3 is C.sub.1-10alkyl. In
certain preferred such embodiments, R.sup.3 is selected from
methyl, ethyl, propyl, and isopropyl, preferably methyl.
[0115] In certain embodiments, R.sup.3' is selected from amino,
cyano, halogen, aryl, aralkyl, heteroaryl, heteroaralkyl, carboxyl,
C.sub.1-10alkyl, C.sub.1-10alkenyl, and C.sub.1-10alkynyl. In
preferred such embodiments, R.sup.3' is selected from aryl,
aralkyl, heteroaryl, heteroaralkyl, carboxyl, C.sub.1-10alkenyl,
and C.sub.1-10alkynyl
[0116] In certain embodiments, R.sup.4 is selected from --OH, --H,
--CH.sub.3, --OC(O)C.sub.1-10aralkyl, --OC(O)C.sub.1-10alkyl, and
--OC(O)aryl. In certain such embodiments, R.sup.4 is selected from
--OC(O)C.sub.1-10aralkyl, --OC(O)C.sub.1-10alkyl, and
--OC(O)aryl.
[0117] In certain embodiments, R.sup.4 is amino. In certain such
embodiments, R.sup.4 is NH.sub.2.
[0118] In certain embodiments, R.sup.5 is selected from cyano,
C.sub.1-10alkoxy, amino, O-aralkyl, --OC(O)C.sub.1-10aralkyl,
--OC(O)C.sub.1-10alkyl, and --OC(O)aryl.
[0119] In certain embodiments, X is S, W is (R)(R), wherein each
occurrence of R is H, n is 1, R.sup.1 and R.sup.2 are independently
selected from methyl, ethyl, propyl, and isopropyl, R.sup.3 and
R.sup.3' are H, R.sup.4 is selected from OH,
--OC(O)C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, and --OC(O)aryl
and, and R.sup.5 is selected from OH, --OC(O) C.sub.1-10aralkyl,
--OC(O) C.sub.1-10alkyl, and --OC(O)aryl. In certain such
embodiments, R.sup.1 and R.sup.2 are the same and are together
selected from methyl, ethyl, propyl, and isopropyl.
[0120] In certain embodiments, X is S, W is O, n is 1, R.sup.1 and
R.sup.2 are both methyl, R.sup.3 is selected from H and COOR.sup.6,
R.sup.3' is H, and R.sup.4 is selected from H and a glutamine
substituent, and R.sup.5 is selected from OH and a glycine
substituent. In certain such embodiments, R.sup.3 is COOR.sup.6,
R.sup.4 is H, R.sup.5 is OH, and R.sup.6 is H.
[0121] In certain embodiments, compounds of formula (I) are
selected from ##STR5##
[0122] In certain embodiments, compounds of formula (I) are
selected from ##STR6##
[0123] In certain embodiments, compounds of formula (I) are
selected from ##STR7##
[0124] Another aspect of the invention relates to a compound of
formula (II) ##STR8## or a pharmaceutically acceptable salt
thereof, wherein the melting point of the compound in its
crystalline form is greater than 125.degree. C., more preferably
greater than 130.degree. C., and most preferably greater than
135.degree. C. In certain embodiments, the melting point of the
compound in its crystalline form is in the range of about
125-150.degree. C., preferably in the range of about
130-145.degree. C., more preferably in the range of about
135-140.degree. C. In certain embodiments, wherein a compound of
formula (II) is associated with pyridine hydrochloride, the two
compounds are present in a ratio of 1:0.9 to 1:1.1, preferably
about 1:1. In certain such embodiments, the two compounds form a
complex comprising one molecule of each compound. Unexpectedly, it
was found that when the ratio of pyridine hydrochloride to the
compound of formula (II) was reduced, the biological activity
against cancer was maintained, as compared with the same arsenical
in which the amount of pyridine hydrochloride was increased.
[0125] If a chiral center is present, all isomeric forms are within
the scope of the invention. Regarding the stereochemistry, the
Cahn-Ingold-Prelog rules for determining absolute stereochemistry
are followed. These rules are described, for example, in Organic
Chemistry, Fox and Whitesell; Jones and Bartlett Publishers,
Boston, Mass. (1994); Section 5-6, pp 177-178, which section is
hereby incorporated by reference.
[0126] In certain embodiments, the organic arsenicals are compounds
having a structure of formula (III) ##STR9## wherein [0127] X is S
or Se, preferably S; [0128] W is O, S, or (R)(R), where each
occurrence of R is independently H or a C.sub.1-2alkyl, preferably
O; [0129] Z is CH or N; [0130] R.sup.1 and R.sup.2 are
independently C.sub.1-10alkyl, preferably R.sup.1 and R.sup.2 are
independently selected from methyl, ethyl, propyl, and isopropyl;
and [0131] R.sup.5 is --OH, cyano, C.sub.1-10alkoxy, amino,
O-aralkyl, O-aralkyl, --OC(O) C.sub.1-10aralkyl, --OC(O)
C.sub.1-10alkyl, --OC(O)aryl, or a glycine substituent, preferably
OH; [0132] R.sup.6 is H or C.sub.1-10alkyl; [0133] R.sup.7 is
selected from halogen, --OH, C.sub.0-6alkyl-COOR.sup.6,
C.sub.1-6alkyl, C.sub.1-6alkoxy, amino, amido, cyano, and nitro;
[0134] m is an integer from 0 to 4, preferably 0.
[0135] In certain embodiments, W is (R)(R) and each occurrence of R
is independently H or a C.sub.1-2alkyl. In certain such
embodiments, each occurrence of R is H.
[0136] In certain embodiments, R.sup.5 is selected from cyano,
C.sub.1-10alkoxy, amino, O-aralkyl, --OC(O) C.sub.1-10aralkyl,
--OC(O) C.sub.1-10alkyl, and --OC(O)aryl.
[0137] In certain embodiments X is S, W is O, R.sup.1 and R.sup.2
are independently selected from methyl, ethyl, propyl, and
isopropyl, and R.sup.5 is OH. In certain such embodiments, R.sup.1
and R.sup.2 are the same and are together selected from methyl,
ethyl, propyl, and isopropyl. In certain such embodiments, R.sup.1
and R.sup.2 are both methyl.
[0138] In certain embodiments, Z is N.
[0139] In certain embodiments, Z is CH.
[0140] In certain embodiments, a compound of formula (III) is
selected from ##STR10##
[0141] In certain embodiments, a compound of formula (III) is
##STR11##
[0142] In other embodiments, the organic arsenicals are compounds
having a structure of formula (IV) ##STR12## wherein [0143] X is S
or Se, preferably S; [0144] W is O, S, or (R)(R), where each
occurrence of R is independently H or a C.sub.1-2alkyl, preferably
O; [0145] R.sup.1 and R.sup.2 are independently C.sub.1-10alkyl,
preferably R.sup.1 and R.sup.2 are independently selected from
methyl, ethyl, propyl, and isopropyl; and [0146] R.sup.5 is --OH,
cyano, C.sub.1-10alkoxy, amino, O-aralkyl, O-aralkyl, --OC(O)
C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, --OC(O)aryl, or a
glycine substituent, preferably OH; [0147] R.sup.6 is H or
C.sub.1-10alkyl; [0148] R.sup.7 is selected from halogen, --OH,
C.sub.0-6alkyl-COOR.sup.6, C.sub.1-6alkyl, C.sub.1-6alkoxy, amino,
amido, cyano, and nitro; [0149] m is an integer from 0 to 4,
preferably 0.
[0150] In certain embodiments, W is (R)(R) and each occurrence of R
is independently H or a C.sub.1-2alkyl. In certain such
embodiments, each occurrence of R is H.
[0151] In certain embodiments, R.sup.5 is selected from cyano,
C.sub.1-10alkoxy, amino, O-aralkyl, --OC(O)C.sub.1-10-aralkyl,
--OC(O) C.sub.1-10alkyl, and --OC(O)aryl.
[0152] In certain embodiments X is S, W is O, R.sup.1 and R.sup.2
are independently selected from methyl, ethyl, propyl, and
isopropyl, and R.sup.5 is OH. In certain such embodiments, R.sup.1
and R.sup.2 are the same and are together selected from methyl,
ethyl, propyl, and isopropyl. In certain such embodiments, R.sup.1
and R.sup.2 are both methyl.
[0153] In certain preferred embodiments, a compound of formula
(III) has the following structure ##STR13##
[0154] Another aspect of the invention relates to a method for the
synthesis of a compound of formula (I) in a manner analogous to
that shown in Example 13 and described in Banks, C. H., et al. (J.
Med. Chem. (1979) 22: 572-575) the contents of which are hereby
incorporated in their entirety by reference, wherein a compound
having a structure of formula (C.sub.1-10alkyl).sub.2As(O)OH is
dissolved in a water/hydrochloric acid solution adjusted to pH 3
and a stream of sulfur dioxide is passed through the solution to
provide a compound having a structure of formula
(C.sub.1-10alkyl).sub.2AsCl which is reacted with a compound having
a structure of formula ##STR14## wherein [0155] X is S or Se,
preferably S; [0156] W is O, S, or (R)(R), where each occurrence of
R is independently H or a C.sub.1-2alkyl, preferably O or (R)(R);
[0157] n is 0 or 1, preferably 1; [0158] R.sup.3 is --H,
C.sub.1-10alkyl, or C.sub.0-6alkyl-COOR.sup.6; [0159] R.sup.3' is
H, amino, cyano, halogen, aryl, aralkyl, heteroaryl, heteroaralkyl,
carboxyl, C.sub.1-10alkyl, C.sub.1-10alkenyl, or C.sub.1-10alkynyl,
preferably H; [0160] R.sup.4 is --OH, --H, --CH.sub.3, amino,
--OC(O) C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, or --OC(O)aryl;
[0161] R.sup.5 is --OH, cyano, C.sub.1-10alkoxy, amino, O-aralkyl,
--OC(O) C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, --OC(O)aryl, or
a glycine substituent; and [0162] R.sup.6 is H or C.sub.1-10alkyl,
preferably H; wherein both compounds are treated with pyridine in
an acceptable organic solvent to provide a compound of formula
(I).
[0163] In certain embodiments, W is (R)(R) and each occurrence of R
is independently H or a C.sub.1-2alkyl. In certain such
embodiments, each occurrence of R is H.
[0164] In certain embodiments, R.sup.3 is --H or
C.sub.0-6alkyl-COOR.sup.6. In certain such embodiments, R.sup.3 is
selected from --COOR.sup.6, --CH.sub.2COOR.sup.6,
--CH.sub.2CH.sub.2COOR.sup.6, --CH(CH.sub.3)COOR.sup.6,
--CH(CH.sub.2CH.sub.3)COOR.sup.6, or
--CH.sub.2CH.sub.2CH.sub.2COOR.sup.6, wherein R.sup.6 is
C.sub.1-10alkyl.
[0165] In certain embodiments, R.sup.3 is C.sub.1-10alkyl. In
certain preferred such embodiments, R.sup.3 is selected from
methyl, ethyl, propyl, and isopropyl, preferably methyl.
[0166] In certain embodiments, R.sup.3' is selected from amino,
cyano, halogen, aryl, aralkyl, heteroaryl, heteroaralkyl, carboxyl,
C.sub.1-10alkyl, C.sub.1-10alkenyl, and C.sub.1-10alkynyl. In
preferred such embodiments, R.sup.3' is selected from aryl,
aralkyl, heteroaryl, heteroaralkyl, carboxyl, C.sub.1-10alkenyl,
and C.sub.1-10-alkynyl.
[0167] In certain embodiments, R.sup.4 is selected from --OH, --H,
--CH.sub.3, --OC(O) C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, and
--OC(O)aryl. In certain such embodiments, R.sup.4 is selected from
--OC(O) C.sub.1-10aralkyl, --OC(O) C.sub.1-10alkyl, and
--OC(O)aryl.
[0168] In certain embodiments, R.sup.4 is amino. In certain such
embodiments, R.sup.4 is NH.sub.2.
[0169] In certain embodiments, R.sup.5 is selected from cyano,
C.sub.1-10alkoxy, amino, O-aralkyl, --OC(O) C.sub.1-10aralkyl,
--OC(O) C.sub.1-10alkyl, and --OC(O)aryl.
[0170] The invention further provides pharmaceutical compositions
comprising formula (I), formula (II), formula (III), or formula
(IV), or a pharmaceutically acceptable salt thereof, and a
pharmaceutically acceptable diluent or carrier. In certain
embodiments, the pharmaceutical composition is an aqueous solution
that has a pH greater than about 5, preferably in the range from
about 5 to about 8, more preferably in the range from about 5 to
about 7.
[0171] Another aspect of the invention provides a method for the
treatment of cancer comprising administering a therapeutically
effective amount of a compound of formula (I), formula (II),
formula (III), or formula (IV).
[0172] The invention also relates to the use of a compound of
formula (I), formula (II), formula (III), or formula (IV), or a
pharmaceutically acceptable salt thereof, in the manufacture of a
medicament for the treatment of cancer.
[0173] In certain embodiments, the cancer is selected from a solid
tumor, such as brain, lung, liver, spleen, kidney, lymph node,
small intestine, pancreas, blood cells, bone, colon, stomach,
breast, endometrium, prostate, testicle, ovary, central nervous
system, skin, head and neck, esophagus, or bone marrow, or a
hematological cancer, such as leukemia, acute promyelocytic
leukemia, lymphoma, multiple myeloma, myelodysplasia,
myeloproliferative disease, or refractory anemia. In certain such
embodiments, the cancer is a leukemia selected from acute and
chronic leukemia.
[0174] Thus, in another aspect, the invention comprises a method of
treating a patient with cancer comprising administering to the
patient a composition comprising a compound of formula I, formula
II, or formula III, or pharmaceutical composition as described
above. The therapeutically effective amount of a compound may be
0.1-1000 mg/kg, 1-500 mg/kg, or 10-100 mg/kg. In particular
embodiments, the method may comprise administering the composition
daily. It is further contemplated that treatment methods may
involve multiple administrations. The method may comprise
administering the compound daily such as by injection. Alternative
routes and methods of administration described in the specification
may also be used and the mode of administration will mainly depend
on the type and location of the cancer. In certain embodiments, the
method further comprises administering one or more additional
agents to the patient. The additional agent may be
all-trans-retinoic acid, 9-cis retinoic acid, Am-80, or ascorbic
acid. The use of other adjunct cancer therapies, such as
chemotherapy, radiotherapy, gene therapy, hormone therapy, and
other cancer therapies known in the art are also contemplated in
conjunction with the methods of the present invention.
[0175] Various methods of administration are contemplated,
including regional, systemic, direct administration and by
perfusion. Such methods include administration by injection, oral
routes, intravenous, intraarterial, intratumoral, administration to
tumoral vasculature, intraperitoneal, intratracheal, intramuscular,
endoscopical, intralesional, percutaneous, subcutaneous, topical,
nasal, buccal, mucosal, anogenital, rectal and the like.
Definitions
[0176] The term "C.sub.x-yalkyl" refers to substituted or
unsubstituted saturated hydrocarbon groups, including
straight-chain alkyl and branched-chain alkyl groups that contain
from x to y carbons in the chain, including haloalkyl groups such
as trifluoromethyl and 2,2,2-tirfluoroethyl, etc. C.sub.0alkyl
indicates a hydrogen where the group is in a terminal position, a
bond if internal. The terms "C.sub.2-yalkenyl" and
"C.sub.2-yalkynyl" refer to substituted or unsubstituted
unsaturated aliphatic groups analogous in length and possible
substitution to the alkyls described above, but that contain at
least one double or triple bond respectively.
[0177] The term "C.sub.1-6alkoxy" refers to an C.sub.1-6alkyl group
having an oxygen attached thereto. Representative alkoxy groups
include methoxy, ethoxy, propoxy, tert-butoxy and the like. An
"ether" is two hydrocarbons covalently linked by an oxygen.
Accordingly, the substituent of an alkyl that renders that alkyl an
ether is or resembles an alkoxy.
[0178] The term "C.sub.1-6aralkyl", as used herein, refers to a
C.sub.1-6alkyl group substituted with an aryl group.
[0179] The term "aryl" as used herein includes 5-, 6-, and
7-membered substituted or unsubstituted single-ring aromatic groups
in which each atom of the ring is carbon. The term "aryl" also
includes polycyclic ring systems having two or more cyclic rings in
which two or more carbons are common to two adjoining rings wherein
at least one of the rings is aromatic, e.g., the other cyclic rings
can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls,
heteroaryls, and/or heterocyclyls. Aryl groups include benzene,
naphthalene, phenanthrene, phenol, aniline, and the like.
[0180] The phrase "pharmaceutically acceptable" is employed herein
to refer to those ligands, materials, compositions, and/or dosage
forms which are, within the scope of sound medical judgment,
suitable for use in contact with the tissues of human beings and
animals without excessive toxicity, irritation, allergic response,
or other problem or complication, commensurate with a reasonable
benefit/risk ratio.
[0181] The term "preventing" is art-recognized, and when used in
relation to a condition, such as a local recurrence (e.g., pain), a
disease such as cancer, a syndrome complex such as heart failure or
any other medical condition, is well understood in the art, and
includes administration of a composition which reduces the
frequency of, or delays the onset of, symptoms of a medical
condition in a subject relative to a subject which does not receive
the composition. Thus, prevention of cancer includes, for example,
reducing the number of detectable cancerous growths in a population
of patients receiving a prophylactic treatment relative to an
untreated control population, and/or delaying the appearance of
detectable cancerous growths in a treated population versus an
untreated control population, e.g., by a statistically and/or
clinically significant amount. Prevention of an infection includes,
for example, reducing the number of diagnoses of the infection in a
treated population versus an untreated control population, and/or
delaying the onset of symptoms of the infection in a treated
population versus an untreated control population. Prevention of
pain includes, for example, reducing the magnitude of, or
alternatively delaying, pain sensations experienced by subjects in
a treated population versus an untreated control population.
[0182] The term "prophylactic or therapeutic" treatment is
art-recognized and includes administration to the host of one or
more of the subject compositions. If it is administered prior to
clinical manifestation of the unwanted condition (e.g., disease or
other unwanted state of the host animal) then the treatment is
prophylactic, (i.e., it protects the host against developing the
unwanted condition), whereas if it is administered after
manifestation of the unwanted condition, the treatment is
therapeutic, (i.e., it is intended to diminish, ameliorate, or
stabilize the existing unwanted condition or side effects
thereof).
[0183] The term "substituted" refers to moieties having
substituents replacing a hydrogen on one or more carbons of the
backbone. It will be understood that "substitution" or "substituted
with" includes the implicit proviso that such substitution is in
accordance with permitted valence of the substituted atom and the
substituent, and that the substitution results in a stable
compound, e.g., which does not spontaneously undergo transformation
such as by rearrangement, cyclization, elimination, etc. As used
herein, the term "substituted" is contemplated to include all
permissible substituents of organic compounds. In a broad aspect,
the permissible substituents include acyclic and cyclic, branched
and unbranched, carbocyclic and heterocyclic, aromatic and
non-aromatic substituents of organic compounds. The permissible
substituents can be one or more and the same or different for
appropriate organic compounds. For purposes of this invention, the
heteroatoms such as nitrogen may have hydrogen substituents and/or
any permissible substituents of organic compounds described herein
which satisfy the valences of the heteroatoms. Substituents can
include, for example, a halogen, a hydroxyl, a carbonyl (such as a
carboxyl, an alkoxycarbonyl, a formyl, or an acyl), a thiocarbonyl
(such as a thioester, a thioacetate, or a thioformate), an alkoxyl,
a phosphoryl, a phosphate, a phosphonate, a phosphinate, an amino,
an amido, an amidine, an imine, a cyano, a nitro, an azido, a
sulfhydryl, an alkylthio, a sulfate, a sulfonate, a sulfamoyl, a
sulfonamido, a sulfonyl, a heterocyclyl, an aralkyl, or an aromatic
or heteroaromatic moiety. It will be understood by those skilled in
the art that the moieties substituted on the hydrocarbon chain can
themselves be substituted, if appropriate.
[0184] A "therapeutically effective amount" of a compound with
respect to the subject method of treatment refers to an amount of
the compound(s) in a preparation which, when administered as part
of a desired dosage regimen (to a mammal, preferably a human)
alleviates a symptom, ameliorates a condition, or slows the onset
of disease conditions according to clinically acceptable standards
for the disorder or condition to be treated or the cosmetic
purpose, e.g., at a reasonable benefit/risk ratio applicable to any
medical treatment.
[0185] As used herein, the term "treating" or "treatment" includes
reversing, reducing, or arresting the symptoms, clinical signs, and
underlying pathology of a condition in manner to improve or
stabilize a subject's condition.
Toxicity of Inorganic vs. Organic Arsenicals
[0186] The use of arsenic trioxide is limited by its toxicity. OA,
on the other hand, are much less toxic, to the extent that the
methylation of inorganic arsenic in vivo into OA has been
considered to be a detoxification reaction. The OA
monomethylarsinic acid and dimethylarsinic acid are the primary
metabolites of inorganic arsenic (Hughes et al., 1998). Inorganic
arsenicals, including arsenic trioxide, have varied effects on many
organ systems, including cardiovascular system, gastrointestinal
tract, kidneys, skin, nervous system, and blood. Inorganic
arsenicals are particularly toxic to the liver, causing
infiltration, central necrosis, and cirrhosis (IARC, 1980: ACGIH,
1991; Beliles et al., 1994; Goyer et al., 1996). There is now
sufficient evidence that inorganic arsenic compounds are skin and
lung carcinogens in humans (Goyer et al., 1996).
[0187] The toxicity of a given arsenical is related to the rate of
its clearance from the body and to the extent of its tissue
accumulation (Beliles et al., 1994). In general, toxicity increases
in the following sequence: organic arsenicals
<As.sup.5+<As.sup.3+ (including arsenic trioxide)<arsine.
Unlike inorganic arsenicals, no deaths or serious cases of toxicity
due to OA have been reported in the literature. Consequently, in
mammals the methylation of inorganic arsenic has been considered a
detoxification mechanism because of the lower toxicity of
methylated OA, and their fast excretion and low retention (Beliles
et al., 1994; Goyer et al., 1996). A good example is that of
dimethylarsinic acid, an organic compound, the predominant urinary
metabolite excreted by most mammals after exposure to inorganic
arsenic, including arsenic trioxide. In in vivo toxicity studies in
mice, after intraperitoneal administration of arsenic trioxide, the
LD.sub.50 (a dose at which 50% of animals die due to acute
toxicity) was 10 mg/kg, (Investigator's Brochure, 1998), while
after administration of dimethylarsinic acid, the LD.sub.50 was 500
mg/kg (MSDS, 1998).
Cancer Treatment
[0188] The organic arsenicals of the current invention may be used
to treat a variety of cancers, including all solid tumors and all
hematological cancers, including leukemia, lymphoma, multiple
myeloma, myelodysplasia, or myeloproliferative disorders. The OA
can also be used to treat hematological cancers that have become
refractory to other forms of treatment.
[0189] Leukemia is a malignant neoplasm of blood-forming tissues,
characterized by abnormal proliferation of leukocytes and is one of
the four major types of cancer. Leukemias are classified according
to the type of leucocyte most prominently involved. Acute leukemias
are predominantly undifferentiated cell populations and chronic
leukemias have more mature cell forms (WO9924029).
[0190] The acute leukemias are divided into lymphoblastic (ALL) and
non-lymphoblastic (ANLL) types and may be further subdivided by
morphologic and cytochemical appearance according to the
French-American-British classification or according to their type
and degree of differentiation. Specific B- and T-cell, as well as
myeloid cell surface markers/antigens are used in the
classification too. ALL is predominantly a childhood disease while
ANLL, also known as acute myeloid leukemia, is a more common acute
leukemia among adults.
[0191] Chronic leukemias are divided into lymphocytic (CLL) and
myeloid (CML) types. CLL is characterized by the increased number
of mature lymphocytes in blood, bone marrow, and lymphoid organs.
Most CLL patients have clonal expansion of lymphocytes with B cell
characteristics. CLL is a disease of older persons. In CML, the
granulocytic cells predominate at all stages of differentiation in
blood and bone marrow, but may also affect liver, spleen, and other
organs. Other malignant hematological disease that may be treated
with the OA of the current invention, include, but are not limited
to: myelodysplasia, myeloproliferative diseases, lymphomas, and
multiple myeloma.
Pharmaceutical Compositions
[0192] The preparation of a pharmaceutical composition that
contains at least one organic arsenical or additional active
ingredient will be known to those of skill in the art in light of
the present disclosure, as exemplified by Remington's
Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990,
incorporated herein by reference. Moreover, for animal (e.g.,
human) administration, it will be understood that preparations
should meet sterility, pyrogenicity, general safety and purity
standards as required by FDA Office of Biological Standards.
[0193] As used herein, "pharmaceutically acceptable carrier"
includes any and all solvents, dispersion media, coatings,
surfactants, antioxidants, preservatives (e.g., antibacterial
agents, antifungal agents), isotonic agents, absorption delaying
agents, salts, preservatives, drugs, drug stabilizers, gels,
binders, excipients, disintegration agents, lubricants, sweetening
agents, flavoring agents, dyes, such like materials and
combinations thereof, as would be known to one of ordinary skill in
the art (see, for example, Remington's Pharmaceutical Sciences,
18th Ed. Mack Printing Company, 1990, pp. 1289-1329, incorporated
herein by reference). Except insofar as any conventional carrier is
incompatible with the active ingredient, its use in the therapeutic
or pharmaceutical compositions is contemplated.
[0194] The organic arsenical may be combined with different types
of carriers depending on whether it is to be administered in solid,
liquid or aerosol form, and whether it need to be sterile for such
routes of administration as injection. The present invention can be
administered intravenously, intradermally, intraarterially,
intraperitoneally, intralesionally, intracranially,
intraarticularly, intraprostaticaly, intrapleurally,
intratracheally, intranasally, intravitreally, intravaginally,
intrarectally, topically, intratumorally, intramuscularly,
intraperitoneally, subcutaneously, subconjunctival,
intravesicularlly, mucosally, intrapericardially, intraumbilically,
intraocularally, orally, topically, locally, injection, infusion,
continuous infusion, localized perfusion bathing target cells
directly, via a catheter, via a lavage, in lipid compositions
(e.g., liposomes), or by other method or any combination of the
forgoing as would be known to one of ordinary skill in the art
(see, for example, Remington's Pharmaceutical Sciences, 18th Ed.
Mack Printing Company, 1990, incorporated herein by reference).
[0195] The actual dosage amount of a composition of the present
invention administered to a patient can be determined by physical
and physiological factors such as body weight, severity of
condition, the type of disease being treated, previous or
concurrent therapeutic interventions, idiopathy of the patient and
on the route of administration. The practitioner responsible for
administration will, in any event, determine the concentration of
active ingredient(s) in a composition and appropriate dose(s) for
the individual subject.
[0196] In certain embodiments, pharmaceutical compositions may
comprise, for example, at least about 0.1% of an organic arsenical
compound. In other embodiments, the an active compound may comprise
between about 2% to about 75% of the weight of the unit, or between
about 25% to about 60%, for example, and any range derivable
therein. In other non-limiting examples, a dose may also comprise
from about 0.1 mg/kg/body weight, 0.5 mg/kg/body weight, 1
mg/kg/body weight, about 5 mg/kg/body weight, about 10 mg/kg/body
weight, about 20 mg/kg/body weight, about 30 mg/kg/body weight,
about 40 mg/kg/body weight, about 50 mg/kg/body weight, about 75
mg/kg/body weight, about 100 mg/kg/body weight, about 200
mg/kg/body weight, about 350 mg/kg/body weight, about 500
mg/kg/body weight, about 750 mg/kg/body weight, to about 1000
mg/kg/body weight or more per administration, and any range
derivable therein. In non-limiting examples of a derivable range
from the numbers listed herein, a range of about 10 mg/kg/body
weight to about 100 mg/kg/body weight, etc., can be administered,
based on the numbers described above.
[0197] In any case, the composition may comprise various
antioxidants to retard oxidation of one or more component.
Additionally, the prevention of the action of microorganisms can be
brought about by preservatives such as various antibacterial and
antifungal agents, including, but not limited to parabens (e.g.,
methylparabens, propylparabens), chlorobutanol, phenol, sorbic
acid, thimerosal or combinations thereof.
[0198] The organic arsenical may be formulated into a composition
in a free base, neutral or salt form. Pharmaceutically acceptable
salts include the salts formed with the free carboxyl groups
derived from inorganic bases such as for example, sodium,
potassium, ammonium, calcium or ferric hydroxides; or such organic
bases as isopropylamine, trimethylamine, histidine or procaine.
[0199] In embodiments where the composition is in a liquid form, a
carrier can be a solvent or dispersion medium comprising, but not
limited to, water, ethanol, polyol (e.g., glycerol, propylene
glycol, liquid polyethylene glycol, etc.), lipids (e.g.,
triglycerides, vegetable oils, liposomes) and combinations thereof.
The proper fluidity can be maintained, for example, by the use of a
coating, such as lecithin; by the maintenance of the required
particle size by dispersion in carriers such as, for example liquid
polyol or lipids; by the use of surfactants such as, for example
hydroxypropylcellulose; or combinations thereof such methods. In
many cases, it will be preferable to include isotonic agents, such
as, for example, sugars, sodium chloride or combinations
thereof.
[0200] Sterile injectable solutions are prepared by incorporating
the active compounds in the required amount of the appropriate
solvent with various of the other ingredients enumerated above, as
required, followed by filtered sterilization. Generally,
dispersions are prepared by incorporating the various sterilized
active ingredients into a sterile vehicle which contains the basic
dispersion medium and/or the other ingredients. In the case of
sterile powders for the preparation of sterile injectable
solutions, suspensions or emulsion, the preferred methods of
preparation are vacuum-drying or freeze-drying techniques which
yield a powder of the active ingredient plus any additional desired
ingredient from a previously sterile-filtered liquid medium
thereof. The liquid medium should be suitably buffered if necessary
and the liquid diluent first rendered isotonic prior to injection
with sufficient saline or glucose. The preparation of highly
concentrated compositions for direct injection is also
contemplated, where the use of DMSO as solvent is envisioned to
result in extremely rapid penetration, delivering high
concentrations of the active agents to a small area.
[0201] The composition must be stable under the conditions of
manufacture and storage, and preserved against the contaminating
action of microorganisms, such as bacteria and fungi. Thus,
preferred compositions have a pH greater than about 5, preferably
from about 5 to about 8, more preferably from about 5 to about 7.
It will be appreciated that endotoxin contamination should be kept
minimally at a safe level, for example, less that 0.5 ng/mg
protein.
[0202] In particular embodiments, prolonged absorption of an
injectable composition can be brought about by the use in the
compositions of agents delaying absorption, such as, for example,
aluminum monostearate, gelatin or combinations thereof.
Combination Therapy
[0203] It is an aspect of this invention that the organic arsenical
can be used in combination with another agent or therapy method,
preferably another cancer treatment. The organic arsenical may
precede or follow the other agent treatment by intervals ranging
from minutes to weeks. In embodiments where the other agent and
expression construct are applied separately to the cell, one would
generally ensure that a significant period of time did not elapse
between the time of each delivery, such that the agent and
expression construct would still be able to exert an advantageously
combined effect on the cell. For example, in such instances, it is
contemplated that one may contact the cell, tissue or organism with
two, three, four or more modalities substantially simultaneously
(i.e., within less than about a minute) with the organic arsenical.
In other aspects, one or more agents may be administered within
about 1 minute, about 5 minutes, about 10 minutes, about 20 minutes
about 30 minutes, about 45 minutes, about 60 minutes, about 2
hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours,
about 7 hours about 8 hours, about 9 hours, about 10 hours, about
11 hours, about 12 hours, about 13 hours, about 14 hours, about 15
hours, about 16 hours, about 17 hours, about 18 hours, about 19
hours, about 20 hours, about 21 hours, about 22 hours, about 23
hours, about 24 hours, about 25 hours, about 26 hours, about 27
hours, about 28 hours, about 29 hours, about 30 hours, about 31
hours, about 32 hours, about 33 hours, about 34 hours, about 35
hours, about 36 hours, about 37 hours, about 38 hours, about 39
hours, about 40 hours, about 41 hours, about 42 hours, about 43
hours, about 44 hours, about 45 hours, about 46 hours, about 47
hours, to about 48 hours or more prior to and/or after
administering the organic arsenical. In certain other embodiments,
an agent may be administered within of from about 1 day, about 2
days, about 3 days, about 4 days, about 5 days, about 6 days, about
7 days, about 8 days, about 9 days, about 10 days, about 11 days,
about 12 days, about 13 days, about 14 days, about 15 days, about
16 days, about 17 days, about 18 days, about 19 days, about 20, to
about 21 days prior to and/or after administering the organic
arsenical. In some situations, it may be desirable to extend the
time period for treatment significantly, however, where several
weeks (e.g., about 1, about 2, about 3, about 4, about 5, about 6,
about 7 or about 8 weeks or more) lapse between the respective
administrations.
[0204] Various combinations may be employed, the organic arsenical
is "A" and the secondary agent, which can be any other therapeutic
agent, is "B": TABLE-US-00001 A/B/A B/A/B B/B/A A/A/B A/B/B B/A/A
A/B/B/B B/A/B/B B/B/B/A B/B/A/B A/A/B/B A/B/A/B A/B/B/A B/B/A/A
B/A/B/A B/A/A/B A/A/A/B B/A/A/A A/B/A/A A/A/B/A
[0205] Administration of the therapeutic compositions of the
present invention to a patient will follow general protocols for
the administration of chemotherapeutics, taking into account the
toxicity, if any. It is expected that the treatment cycles would be
repeated as necessary. It also is contemplated that various
standard therapies or adjunct cancer therapies, as well as surgical
intervention, may be applied in combination with the described
arsenical agent. These therapies include but are not limited to
chemotherapy, radiotherapy, immunotherapy, gene therapy and
surgery. The section below describes some adjunct cancer
therapies:
Chemotherapy
[0206] Cancer therapies also include a variety of combination
therapies with both chemical and radiation based treatments.
Combination chemotherapies include, for example, cisplatin (CDDP),
carboplatin, procarbazine, mechlorethamine, cyclophosphamide,
camptothecin, ifosfamide, melphalan, chlorambucil, busulfan,
nitrosurea, dactinomycin, daunorubicin, doxorubicin, bleomycin,
plicomycin, mitomycin, etoposide (VP16), tamoxifen, raloxifene,
estrogen receptor binding agents, taxol, gemcitabien, navelbine,
farnesyl-protein tansferase inhibitors, transplatinum,
5-fluorouracil, vincristin, vinblastin and methotrexate, or any
analog or derivative variant of the foregoing.
Radiotherapy
[0207] Other factors that cause DNA damage and have been used
extensively include what are commonly known as .gamma.-rays,
X-rays, and/or the directed delivery of radioisotopes to tumor
cells. Other forms of DNA damaging factors are also contemplated
such as microwaves and UV-irradiation. It is most likely that all
of these factors effect a broad range of damage on DNA, on the
precursors of DNA, on the replication and repair of DNA, and on the
assembly and maintenance of chromosomes. Dosage ranges for X-rays
range from daily doses of 50 to 200 roentgens for prolonged periods
of time (3 to 4 wk), to single doses of 2000 to 6000 roentgens.
Dosage ranges for radioisotopes vary widely, and depend on the
half-life of the isotope, the strength and type of radiation
emitted, and the uptake by the neoplastic cells. The terms
"contacted" and "exposed," when applied to a cell, are used herein
to describe the process by which a therapeutic construct and a
chemotherapeutic or radiotherapeutic agent are delivered to a
target cell or are placed in direct juxtaposition with the target
cell. To achieve cell killing or stasis, both agents are delivered
to a cell in a combined amount effective to kill the cell or
prevent it from dividing.
Immunotherapy
[0208] Immunotherapeutics, generally, rely on the use of immune
effector cells and molecules to target and destroy cancer cells.
The immune effector may be, for example, an antibody specific for
some marker on the surface of a tumor cell. The antibody alone may
serve as an effector of therapy or it may recruit other cells to
actually effect cell killing. The antibody also may be conjugated
to a drug or toxin (chemotherapeutic, radionucleotide, ricin A
chain, cholera toxin, pertussis toxin, etc.) and serve merely as a
targeting agent. Alternatively, the effector may be a lymphocyte
carrying a surface molecule that interacts, either directly or
indirectly, with a tumor cell target. Various effector cells
include cytotoxic T cells and NK cells.
[0209] Immunotherapy, thus, could be used as part of a combined
therapy, in conjunction with gene therapy. The general approach for
combined therapy is discussed below. Generally, the tumor cell must
bear some marker that is amenable to targeting, i.e., is not
present on the majority of other cells. Many tumor markers exist
and any of these may be suitable for targeting in the context of
the present invention. Common tumor markers include
carcinoembryonic antigen, prostate specific antigen, urinary tumor
associated antigen, fetal antigen, tyrosinase (p97), gp68, TAG-72,
HMFG, Sialyl Lewis Antigen, MucA, MucB, PLAP, estrogen receptor,
laminin receptor, erb B and p155.
Gene Therapy
[0210] In yet another embodiment, the secondary treatment is a
secondary gene therapy in which a therapeutic polynucleotide is
administered before, after, or at the same time a first therapeutic
agent. Delivery of the therapeutic agent in conjunction with a
vector encoding a gene product will have a combined
anti-hyperproliferative effect on target tissues.
Surgery
[0211] Approximately 60% of persons with cancer will undergo
surgery of some type, which includes preventative, diagnostic or
staging, curative and palliative surgery. Curative surgery is a
cancer treatment that may be used in conjunction with other
therapies, such as the treatment of the present invention,
chemotherapy, radiotherapy, hormonal therapy, gene therapy,
immunotherapy and/or alternative therapies. Curative surgery
includes resection in which all or part of cancerous tissue is
physically removed, excised, and/or destroyed. Tumor resection
refers to physical removal of at least part of a tumor. In addition
to tumor resection, treatment by surgery includes laser surgery,
cryosurgery, electrosurgery, and microscopically controlled surgery
(Mohs' surgery). It is further contemplated that the present
invention may be used in conjunction with removal of superficial
cancers, precancers, or incidental amounts of normal tissue.
EXAMPLES
[0212] The following examples are included to demonstrate preferred
embodiments of the invention. It should be appreciated by those of
skill in the art that the techniques disclosed in the examples
which follow represent techniques discovered by the inventor to
function well in the practice of the invention, and thus can be
considered to constitute preferred modes for its practice. However,
those of skill in the art will, in light of the present disclosure,
appreciate that many changes can be made in the specific
embodiments which are disclosed and still obtain a like or similar
result without departing from the spirit and scope of the
invention.
Example 1
Synthesis of S-dimethylarsino-thiosuccinic acid (MER1),
S-dimethylarsino-salicylic acid (SAL1) and S-(dimethylarsino)
glutathione (SGLU1)
[0213] MER-1: Mercaptosuccinic acid, 4.5 g, was placed in 100 mL of
glyme (1,2-dimethoxyethane) in a 250 mL round-bottom flask. Four mL
of dimethylchloroarsine (0.03 mol) was added drop-wise, followed by
4 mL of diethylamine (0.04 mol), again dropwise. The reaction
mixture was stirred for 20 h at room temperature. A white
precipitate of diethylamine hydrochloride was formed and was
separated by filtration. The solution of MER1 in the glyme was
greatly reduced in volume by evaporation at reduced pressure. White
crystals of MER1 were separated by filtration and washed with cold
distilled water. The colorless crystalline product was then
recrystallized from ethanol-water to a constant melting point of
150.degree. C.
[0214] SAL-1: In a 100 mL flask 5 g of 2-mercapto benzoic acid
(thiosalicylic acid), 75 mL of glyme, 5 mL of dimethylchloroarsine,
and 5 mL diethylamine were placed. The mixture was refluxed for 1
hour under an atmosphere of nitrogen and stirred at room
temperature overnight. The precipitate of diethylamine
hydrochloride was separated by filtration. The filtrate was
evaporated slowly under reduced pressure until crystals of the
product separate. The evaporated solution containing the product
was chilled in ice and the cold solution was filtered. Crystals of
the product were recrystallized from ethanol to a constant melting
point of 97.degree. C.
[0215] SGLU-1: Glutathione (14.0 g, 45.6 mmol) was stirred rapidly
in glyme while dimethylchoroarsine (6.5 g, 45.6 mmol) was added
dropwise. Pyridine (6.9 g, 91.2 mmol) was then added to the slurry
and the mixture was subsequently heated to reflux. The heat was
removed immediately and the mixture stirred at room temperature for
4 h. Isolation of the resultant insoluble solid and
recrystallization from ethanol afforded 4 as the pyridine
hydrochloride complex (75% yield): mp 115-118.degree. C.; NMR
(D.sub.2O) .delta.1.35 (s, 6H), 1.9-4.1 (m's, 10H), 7.8-9.0 (m,
5H); mass spectrum (m/e) 140, 125, 110, 105, 79, 52, 45, 36. This
material is not used for the examples described herein, but has
been used in biological assays as described in Banks, C. H., et al.
(J. Med. Chem. (1979) 22: 572-575), which is incorporated herein by
reference in its entirety.
[0216] The studies that let to the synthesis of MER-1, SGLU-1 and
SAL-1 were funded by the Robert A. Welch foundation of Houston,
Tex., in a grant to inventor Ralph Zingaro.
Example 2
Assay for In Vitro Evaluation
[0217] A variety of in vitro assays were used to determine the
response of cancer cells to the arsenical compounds, compositions,
and/or formulations of the present invention. Some of the responses
assayed included cell survival, cell cycle, apoptosis, and
maturation. The present inventors also designed an assay to
evaluate the requirement of the PML/RAR alpha gene in cancer cells
for sensitivity to the arsenical compositions of the invention.
Provided below is a description of these assays:
Sulforhodamine B Assay
[0218] Various human cancer cells were incubated on a microtiter
plate with or without indicated concentrations of MER1, SAL1, or
SGLU1 for 48 hours, and then sulforhodamine B dye was added to the
cultures. The sulforhodamine B dye is a protein binding dye and
labels live cells. Results are reported as the percent growth of
treated cells when compared to untreated control cells (negative
data indicate cell kill).
MTT and Trypan Blue Assays
[0219] For these assays mononuclear cells from peripheral blood
samples of leukemia patients and normal donors were separated by
Ficoll Hipaque fractionation and resuspended in DMEM complete
medium. Alternatively, cell line cells were used in some cases.
Malignant cells from various human cell lines (usually at
5.times.10.sup.4 cells/mL) or mononuclear cells from peripheral
blood of leukemia patients and healthy donors (1.times.10.sup.6
cells/mL) were incubated in either alpha MEM or RPMI 1640 with or
without various concentrations of MER1, SAL1, or SGLU1. Each
experimental condition was done in triplicate. After the indicated
number of days (usually 3 days) of exposure to MER1, SAL1, or
SGLU1, cell survival was assessed by the addition of a dye to the
wells (either MTT or trypan-blue). The MTT dye changes its color
depending on the presence of live cells in the well. Survival of
cells under MTT treatment was evaluated as a percentage of control
cell growth. The trypan-blue dye penetrates dead cells and live
cells can be counted under the microscope and percentage survival
estimated.
Clonogenic Assay
[0220] Clonogenicity or colony formation was analyzed by obtaining
peripheral blood mononuclear cells (from normal donors or leukemia
patients) which were resuspended in semisolid medium containing
recombinant cytokines and plated in quadruplicate, 0.1 mL/well, in
96-well microtiter plates at 4.times.10.sup.4 cells/0.1 mL density.
Cell aggregates composed of more than 50 cells were counted as one
colony after .about.10 days of incubation at 37.degree. C. in 5%
CO.sub.2 humidified atmosphere. Growth inhibition was evaluated as
a percentage of colony growth as compared to colony growth in
control (no drug) samples.
Analysis of Apoptosis
[0221] Three different methods were used to analyze apoptosis by
assaying different events in the apoptotic pathways. Percentages of
apoptotic cells induced by arsenic derivatives of the invention
were evaluated using flow cytometer. Different methods of staining
cells for apoptosis were utilized to assess different aspects of
apoptotic cascade.
[0222] 1. Annexin V and Propidium Iodide (PI) Staining. Annexin V
binds to cells that express phosphatidylserine on the outer layer
of the cell membrane, while propidium iodide stains the cellular
DNA of cells with a compromised cell membrane. This allows live
cells (unstained with either fluorochrome) to be discriminated from
apoptotic cells (stained only with annexin V) and necrotic cells
(stained with both annexin and PI).
[0223] Following treatment of cells in culture with indicated
arsenicals of the invention for the indicated time, cells were
washed in phosphate-buffered saline (PBS) and resuspended in 100
.mu.L of binding buffer containing annexin V-FITC (Travigene) and
incubated for 15 minutes in the dark. Cells were analyzed on flow
cytometer after the addition of PI.
[0224] 2. Cytofluorometric Analysis of the Mitochondrial Membrane
Potential. To evaluate the changes in the potential of
mitochondrial membrane, following treatment with arsenic
derivatives for the indicated time, cells were incubated in
submicromolar concentrations of MitoTracker probes. MitoTracker
probes passively diffuse across the plasma membrane and accumulate
in active mitochondria. Cells were stained with two colors:
MitoTracker Red CMXRos (Molecular Probes) and MitoTracker Green FM
(Molecular Probes). Cells were washed in PBS, stained with
MitoTracker dyes and incubated for 1 hour at 37.degree. C. in the
dark. CMXRos is incorporated into mitochondria driven by the
mitochondrial membrane potential and reacts with thiol residues to
form covalent thiol ester bonds. MitoTracker Green FM dye
preferentially accumulates in mitochondria regardless of
mitochondrial membrane potential, making it a useful tool for
determining mitochondrial mass.
[0225] 3. Detection of Caspase Activity. In order to monitor
caspase activity by flow cytometry, the fluorogenic substrate
PhiPhiLux G1D1 (Oncoimmunin) was used. PhiPhiLux G1D1 is a
substrate for the detection and measurement of caspase 3 and
caspase 3-like activities in living cells. Following treatment with
the arsenic derivatives of the invention for indicated time, cells
were washed in PBS, resuspended in 5 .mu.L substrate solution and
incubated for 1 hour at 37.degree. C. in the dark. After incubation
cells were washed, and few minutes before flow cytometry analysis,
PI was added to exclude necrotic cells during analysis.
Cell Cycle Analysis
[0226] Cell cycle was analyzed as follows: after 72 h of incubation
with the different arsenical compounds of the invention, cells
(1.times.10.sup.6) were washed twice in PBS. The cell pellet was
resuspended in staining solution that contained hypotonic solution
(RNAse solution, Triton X-100, sodium citrate, PEG) and PI (25
.mu.g/mL). Cells were incubated 15 minutes in dark at room
temperature and then they were analyzed by flow cytometer using
CellQuest program (Becton-Dickinson).
Maturation Analysis
[0227] Human acute prolymphocytic leukemia cell line NB4 was used
to test the effect of the arsenicals of the invention on the
maturation of leukemic cells. Phycoerythrin-conjugated anti-CD11b
monoclonal antibody (Becton-Dickinson) was used as a marker of
mature myelocytes. After 72 h of incubation with drugs, cells were
washed in PBS. Cells in the density of 1.times.10.sup.6 cells/mL
were then incubated with monoclonal antibody in dilution 1:10 in
dark at room temperature for 15 minutes. After incubation cells
were washed in PBS and the pellet was resuspended in 500 .mu.L of
PBS. To exclude nonspecific binding appropriate isotypic control
was prepared in the same manner. Cells were sorted using a flow
cytometer and analyzed using CellQuest Document Analysis.
Role of PML/Rar alpha Protein.
[0228] Arsenic trioxide is approved as a treatment for acute
prolymphocytic leukemia and it kills APL cells in large part due to
their expression of PML/Rar alpha gene and protein. The following
system was used to establish whether the presence of PML/RAR alpha
fusion protein in the leukemic cells contributes to the observed
sensitivity of leukemic cells to SGLU and MER1: U937 cells, known
to be resistant to arsenic trioxide, were transfected with PML/RAR
alpha gene. The transfected cells (U937/PR9) were kindly provided
by Dr. Michael Andreeff (M.D. Anderson Cancer Center). The PML/RAR
alpha gene becomes functional in the presence of zinc.
Zn.sup.2+-inducible expression of the PML/RAR alpha gene in the
U937/PR9 cell line is described in Grignani et al. (Cell, (1993)
74:423-431). In order to establish the PML/RAR alpha expression,
cells were treated with 0.1 mM ZnSO.sub.4 for 3 h before the
addition of arsenic compounds for 72 h. PML/RAR.alpha. expression
is typically established at about 3 h following zinc addition to
the cells and is stable for 48 hours.
Example 3
In vitro Evaluation of Anticancer Activity of MER1, SAL1, and
SGLU1
[0229] The anti-leukemic activity of MER1 has been evaluated by 3
day MTT assay/trypan blue exclusion method against 6 different
human leukemia cell lines: AML2, AML3 and HL60 (an AML derived cell
line), NB4 (an APL derived cell line), K562 (a CML-BP derived cell
line), and KBM7 (an AML derived cell line). MER1 was most effective
against NB4 cells with an IC.sub.50 (the concentration that results
in 50% survival of cells, as compared to untreated control cells)
at 1 .mu.M (FIG. 1). MER1 treatment of other cell lines, including
the analysis of AML2 cells and KBM7 cells by the MTT assay and AML2
cells (see FIG. 2), AML3 cells, K562 cells, and HL60 cells by the
trypan blue assay showed IC.sub.50 values in the range of 1.5-4
.mu.M. This activity was similar to the activity of arsenic
trioxide against these cell lines (examples of arsenic trioxide
activity are shown in FIG. 1 and FIG. 2). MER1 was also tested for
anticancer activity by the National Institute Of Health (NIH), in
vitro against a panel of 60 tumor cell lines using sulforhodamine B
assay (FIG. 3). The compound showed evidence of activity at low
concentrations against a variety of tumor cell lines, but
particularly against leukemia cells tested. At the concentration of
1 .mu.M of MER1, the growth of all 6 leukemia cell lines tested was
significantly retarded (<20% growth; FIG. 3, first panel).
[0230] The antileukemic activity of SAL1 has been evaluated by 3
day trypan blue assays against 2 human cell lines: HL60 cells
(depicted in FIG. 4), and Z138 (an ALL cell line). SAL1 was also
tested for anticancer activity by the NIH in vitro against a panel
of 60 tumor cell lines using sulforhodamine B assay (FIG. 5). The
compound showed evidence of activity at low concentrations against
a variety of tumor cell lines.
[0231] The antileukemic activity of SGLU1 has been evaluated by 3
day MTT assay against 9 human leukemia cell lines: NB4, CAG
(multiple myeloma cell line), JURKAT and RAJI (lymphoma cell line),
HL60, AML2, AML3, KBM5 (CML-BP derived cell line, and KBM7. The
results for the cell line NB4 are depicted in FIG. 6. The
antileukemic activity of SGLU1 was also been evaluated by 3 day
trypan blue exclusion method against 6 human leukemia cell lines:
NB4, CAG, JURKAT, HL60, KBM3 (AML cell line), and Z119 (an ALL cell
line), showing similar results. The activity was similar to the
activity of arsenic trioxide as depicted in FIG. 6. The
antileukemic activity of SGLU1 was also been evaluated by 5 day
clonogenic assay against HL60 human leukemia cells (FIG. 7). SGLU1
was also tested for anticancer activity by the NIH in vitro against
a panel of 60 tumor cell lines using sulforhodamine B assay (FIG.
8). The compound showed evidence of activity at low concentrations
against a variety of tumor cell lines.
Example 4
Toxicity Determination of MER1 and SGLU1 against Malignant and
Normal Blood Cells
[0232] MER1 was tested against blood mononuclear cells (>80%
blasts) from 5 leukemia patients (3 with AML, one with CML-BP, and
one with ALL; FIGS. 9-13). In short-term cell cultures MER1 was as
effective as arsenic trioxide (FIGS. 9, 10, and 12). In addition,
toxicity of MER1 against normal peripheral blood mononuclear cells
was evaluated in samples from 4 healthy donors. In short-term cell
suspension cultures by MTT assay MER1 was less toxic to normal
cells than malignant cells from leukemia patients (FIG. 14). Most
importantly, in long-term clonogenic assay MER1 was less toxic to
normal cells than arsenic trioxide (FIG. 15).
[0233] SGLU1 was tested against blood mononuclear cells from 3
leukemia patients, including a patient with CLL (FIG. 16 which
shows a comparison to arsenic trioxide), and 2 patients with AML
(FIG. 17). In long-term clonogenic assay SGLU1 was less toxic then
arsenic trioxide to normal cells (FIG. 18). In addition to the 8
day clonogenic assay shown in FIG. 18, 9 day and 13 day clonogenic
assays have also been performed.
Example 5
Formulation and Stability of MER1
[0234] Data has been obtained that shows that MER1 is stable for at
least 2 months when dissolved in phosphate buffered saline, as the
solutions have maintained cytotoxic activity at the same level in
in vitro experiments done during this time period (FIG. 19). In
addition detailed pharmaceutical evaluation of MER1 and SGLU1 were
performed.
I. Pharmaceutical Evaluation of MER-1
[0235] MER-1 was found to have a sufficient solubility and
stability to be acceptable for administration in a clinical setting
(see data below). It is also sufficiently stable that solutions can
be extemporaneously compounded for use in animal testing and
possibly an early Phase I study. However, the solution stability is
not adequate for manufacturing of larger batches of a liquid dosage
form for use in larger clinical trials and distribution in the
commercial marketplace where long-term storage is required. A
lyophilized dosage form that is reconstituted at the time of use is
contemplated for these applications. Preparations of such
lyophilized compositions are well known in the art.
A. Solubility
[0236] MER-1 has an aqueous solubility of about 15 mg/mL. Higher
MER-1 concentrations up of about 150 mg/mL can be achieved by the
use of 0.1 N sodium hydroxide to adjust the pH to 6. In ethanol,
MER-1 has a solubility of more than 100 mg/mL.
B. Solution pH
[0237] The natural pH values of aqueous solutions of MER-1 are as
follows: TABLE-US-00002 0.1 mg/mL pH 3.7 1 mg/mL pH 3.1 10 mg/mL pH
2.3
C. Solution Stability
[0238] The effects of various pH values were evaluated at a
concentration of 10 mg/mL in 0.9% sodium chloride injection.
Samples having a pH of 2.3 (natural pH) and also adjusted with
sodium hydroxide to pH 5, 7.1, and 8.5 have been evaluated over a
period of 3 months under refrigeration. The samples at pH 5
demonstrated better stability retaining about 89% of the initial
concentration after 3 months. The solutions at pH 7.1 and 8.5
retained about 92% and 96%, respectively, after 14 days but fell
below 90% after that time. The pH 2.3 samples were stable for 7
days but developed a precipitate after that time. See Table 2.
[0239] MER-1 was less stable in aqueous solutions at lower
concentrations, but was increasingly stable at higher
concentrations. At 0.1 mg/mL in water, about 40% of the drug was
lost in as little as one hour. As concentrations increased from 1
to 10 mg/mL in 0.9% sodium chloride injection, the drug was stable
for increasingly longer periods. The 10-mg/mL concentration was
stable for up to 3 months under refrigeration, but unacceptable
decomposition occurred after that time. See Table 3. TABLE-US-00003
TABLE 2 pH Stability Profile of MER-1 10 mg/mL in 0.9% Sodium
Chloride Injection Assay Interval Remaining MER-1 (%) (Days) pH 2.3
pH 5.0 pH 7.1 pH 8.5 0 100 100 100 100 7 102 105 96 97 14 ppt 101
92 96 30 100 80 82 60 91 90 91 180 87
[0240] TABLE-US-00004 TABLE 3 MER-1 Solution Stability at Varying
Concentrations in 0.9% Sodium Chloride Injection Assay Interval
Remaining MER-1 (%) (days) 0.1 mg/mL.sup.a 1 mg/mL 2 mg/mL 10 mg/mL
0 60.sup.b 100 100 100 7 94 99 105 14 89 102 101 21 81 96 102 30 79
98 100 60 88 91 90 84 91 180 87 .sup.aIn water. .sup.bAbout 40%
loss occurred in 60 minutes. .sup.cNot determined at this
interval.
II. Pharmaceutical Evaluation of SGLU-1
[0241] SGLU-1 was found to have sufficient solubility and stability
to be acceptable for administration in a clinical setting. It was
also sufficiently stable that solutions can be extemporaneously
compounded for use in animal testing and possibly an early Phase I
study. However, the solution stability is not adequate for
manufacturing of larger batches of a liquid dosage form for use in
larger clinical trials and distribution in the commercial
marketplace where long-term storage is required. A lyophilized
dosage form that is reconstituted at the time of use is
contemplated for these applications.
A. Solubility
[0242] SGLU-1 had an aqueous solubility of about 60 mg/mL. Higher
SGLU-1 concentrations were achieved by the use of 0.1 N sodium
hydroxide to raise the solution pH. However, the drug appeared to
be unstable in an alkaline environment. SGLU-1 was insoluble in
ethanol.
B. Solution pH
[0243] The natural pH values of aqueous solutions of SGLU-1
are:
[0244] 0.1 mg/mL, pH 3.9
[0245] 1 mg/mL pH 3.2
[0246] 2.5 mg/mL pH 3.0
[0247] 60 mg/mL pH 2.7
C. Solution Stability
[0248] The effects of various pH values were evaluated at a
concentration of 2.5 mg/mL in 0.9% sodium chloride injection.
Samples having a pH of 3 (natural pH) and also adjusted with sodium
hydroxide to pH 5 and 7 were evaluated over 30 days under
refrigeration. The samples at pH 5 demonstrated slightly better
stability retaining about 90% concentration after 30 days. The
solutions at pH 3 and 7 retained about 84% and 82%, respectively.
See Table 4.
[0249] SGLU-1 at concentrations of 20 mg/mL and 50 mg/mL in 0.9%
sodium chloride injection adjusted to pH 5 have undergone stability
testing. Less than 10% loss occurred through 60 days of storage
under refrigeration. The stability results are shown in Table
5.
[0250] SGLU-1 was less stable at lower concentrations. At 0.1 mg/mL
in water, more than 10% decomposition occurred in 24 hours at room
temperature. TABLE-US-00005 TABLE 4 pH Stability Profile of SGLU-1
2.5 mg/mL in 0.9% Sodium Chloride Injection Assay Interval
Remaining SGLU-1 (%) (Days) pH 3.0 pH 5.0 pH 7.0 0 100 100 100 3
104 101 97 5 100 99 93 7 100 97 91 14 97 97 91 21 87 93 84 30 84 91
82
[0251] TABLE-US-00006 TABLE 5 Stability if SGLU-1 20 mg/mL and 50
mg/mL in 0.9% Sodium Chloride Injection at 4.degree. C. Assay
Interval Remaining SGLU-1 (%) (Days) 20 mg/mL 50 mg/mL 7 101 97 14
98 98 30 94 94 60 92 93 90 85 87
Example 6
Mechanisms for MER1, SAL1, and SGLU1
[0252] The induction of apoptosis, effects on the cell cycle,
induction of maturation, and degradation of aberrant PML/Rar alpha
fusion protein, have all shown to be mechanisms of action of
arsenic trioxide. The present inventors have examined the potential
of MER1 to induce apoptosis in HL60 human leukemia cells (assay
time 1-3 days). The induction of apoptosis followed closely
diminished percentage of surviving cells (FIGS. 20, 21 & 22).
Additional studies using both MER1 and SGLU have established that
the induction of apoptosis (annexin V staining) by these compounds
involves change of the potential of mitochondrial membrane (CMXRos
staining) and activation of caspases (PhiPhiLux staining) see FIGS.
23A, 23B, 23C, 23D, 23E, & 23F.
[0253] It has been reported that arsenic trioxide induced
maturation of cells expressing PML/Rar alpha gene. To test whether
SGLU and MER1 have similar capability NB4 cells (expressing the
PML/Rar alpha gene) were used and, after 3 days of exposure to
arsenicals, the expression of CD11b on the surface of the cells was
measured by flow cytometer. CD11b is a maturation marker for
myeloid cells. Data is presented in FIG. 24 that indicated that
SGLU and MER1 do not induce maturation. Possible cell cycle
disturbance in HL60 cells treated with the different arsenicals of
the invention was assessed using flow cytometry and staining with
propidium iodide. It was found that SGLU caused marked accumulation
of cells in S-phase of cell cycle, with MER1 causing a similar
effect to lesser degree (FIGS. 25A, 25B). FIG. 25C describes
S-phase accumulation of cells in response to arsenic trioxide.
[0254] To establish whether the presence of PML/Rar alpha fusion
protein in the leukemic cells contributes to the observed
sensitivity of leukemic cells to SGLU and MER1 the following system
was used: U937 cells, known to be resistant to arsenic trioxide,
were transfected with PML/Rar alpha gene. This gene becomes
functional in the presence of zinc. Thus, transfected U937 cells
(U937/PR9) were treated with different arsenical with or without
zinc. Results are shown in FIGS. 26A, 26B, & 26 C which
indicate that the presence of functional PML/Rar alpha gene is a
prerequisite for cells to become sensitive to arsenic trioxide but
had no influence on the sensitivity of the cells to SGLU and
MER1.
Example 7
In vivo Evaluation of the Therapeutic Potential of MER1, SAL1, and
SGLU1
[0255] The animal model of human leukemia was represented by severe
combined immunodeficient (SCID) mice bearing human leukemia cells.
This model was unique in that it allows growth of human leukemia in
animals in a mode similar to that seen in patients. It offered an
opportunity to rapidly test the in vivo efficacy of new drugs at
different dose levels and schedules. Furthermore, not only can
animal survival be monitored, but also the effect of treatment on
the dissemination pattern of the disease. Treatment of SCID mice
typically started 2 days after inoculation with human leukemic
cells. Initial in vivo experiments in SCID mice injected with one
human leukemia cell line determined dose and schedule of MER1,
SAL1, or SGLU1 for the other mice model as well as for initial
human trials.
[0256] Animals were monitored daily and sacrificed when moribund or
at the completion of the study (usually double the survival time of
the control group). Necropsy is performed on animals that survive
for long time and tissues are analyzed for the presence of human
DNA by polymerase chain reaction (PCR) using primers specific for
DNA sequences of HLA-DQ.alpha.. Since leukemia is a systemic
disease, the presence of minimal residual disease is studied by
checking for HLA-DQ.alpha. in DNA from different mouse tissues.
[0257] Prerequisites for in vivo therapeutic experimentation in
SCID mice are 1) the verification of leukemia cells engraftment in
animals and 2) the determination of acute toxicity of tested
compounds (definition of maximally tolerated dose).
[0258] I. Verification of Leukemia Cells Engraftment in Animals.
The first in vivo experiment involved 4 groups of SCID mice. Five
mice per group were inoculated intraperitoneally with human
leukemia cells of different types: HL60 (AML), KBM5 (CML-BP),
KBM7-acute myeloid leukemia, and Z119 (ALL). HL60 and KBM5 cells
showed excellent engraftment: in HL60 group all mice died within
days 31 and 36 after inoculation, while in the KBM5 group mice died
within 34th and 36th day. The engraftment was verified by
performing PCR for DNA sequences of human HLA-DQ.alpha. (test was
positive in all tissues from all the mice). At day 100, there were
still 4 of 5 mice alive in KBM7 and 5 of 5 mice alive in Z119
group. At that day all mice were sacrificed and tissues analyzed by
PCR for HLA-DQ.alpha.. Testing was negative indicating lack of
leukemia cell engraftment. Alternative cell lines of same type are
required for therapeutic studies.
II. Determination of Acute Toxicity of Tested Compounds. For
toxicology testing, immunocompetent Swiss Webster mice were used.
It was confirmed that LD.sub.50 concentration for arsenic trioxide
was 10 mg/kg.
[0259] A. Brief Toxicity Testing Of SLGU1 in Swiss-Webster Mice.
Two studies were performed on Swiss-Webster mice to test the
toxicity of SGLU 1. In the first study, SGLU1 was administered at
doses of 178 mg/kg; 285 mg/kg; and 357 mg/kg via the IP route. The
toxicity was measured by the mortality of mice. It was found that
the mice tolerated the 178 mg/kg and the 285 mg/kg doses of SGLU 1
well. The data of this study are summarized in Table 6.
TABLE-US-00007 TABLE 6 Brief Toxicity Testing Of SLGU1 Dose (mg/kg)
Administered IP 178 285 357 Dead/Total Number 0/5 1/5 5/5
[0260] In the second study the toxicity with each mouse weighted
were studies for administration of SGLU1 by both the IP and IV
routes at doses of 318 mg/kg and 375 mg/kg. Thus, it was
established that LD.sub.50 concentration for SGLU1 is 350 mg/kg.
The results are summarized in Table 7. TABLE-US-00008 TABLE 7
Better Performance With Each Mouse Weighted Dose (mg/kg) 318 375
Dead/Total Number for IP Administration 0/5 4/5 Dead/Total Number
for IV Administration 1/5 5/5
[0261] B. Brief Toxicity Testing Of MER-1 in Swiss-Webster Mice.
Two studies were performed on Swiss-Webster mice to test the
toxicity of MER-1. In the first study, MER-1 was administered at
doses of 71 mg/kg; 107 mg/kg; and 143 mg/kg via the IP route. The
toxicity was measured by the mortality of mice. It was found that
the mice tolerated the 71 mg/kg and the 107 mg/kg doses of MER-1
well with no mortality. The data of this study are summarized in
Table 8. TABLE-US-00009 TABLE 8 Brief Toxicity Testing Of MER-1
Dose (mg/kg) Administered IP 71 107 143 Dead/Total Number 0/5 0/5
5/5
[0262] In the second study the toxicity with each mouse weighted
were studies for administration of MER-1 by both the IP and IV
routes at doses of 125 mg/kg; 156 mg/kg; and 170 mg/kg. Thus,
inventors have established that LD.sub.50 concentration for MER1
was 150 mg/kg. The results are summarized in Table 9.
TABLE-US-00010 TABLE 9 Better Performance With Each Mouse Weighted
Dose (mg/kg) 125 156 170 Dead/Total Number for IP Administration
0/5 2/5 5/5 Dead/Total Number for IV Administration 0/5 0/5 5/5
C. Brief Toxicity Testing Of SAL1 in Swiss-Webster Mice. Similar to
experiments above, brief toxicity testing of SAL1 established that
LD.sub.50 concentration for SAL1 was 50 mg/kg.
Example 8
Pharmacokinetics of MER1, SAL1, and SGLU1
[0263] The pharmacokinetic disposition of MER1, SAL1, and SGLU1 are
evaluated in mice following intravenous administration via the tail
vein. A dose near the previously determined MTD is studied
initially. Blood samples are collected at different sampling time
points (0 (pre), 5, 10, 15, 30, 45, 60 min and 2, 3, 4, 6, 8, 12,
16, 24, 48, 72 hrs) following drug administration (8 mice/time
point). For blood collection, mice are euthanized by CO.sub.2
inhalation, then decapitated and blood collected by exsanguination.
Blood samples are collected in test tubes containing heparin,
centrifuged, and plasma separated and stored at -80.degree. C.
until analysis. Studies are repeated and plasma ultrafiltrate
collected via centrifugation of plasma at 2000 g.times.20 minutes
in Amicon Centrifree micropartition units. Ultrafiltrate is stored
at -80.degree. C. until analysis. In selected groups, various
tissues are harvested post-mortem and frozen for analysis of tissue
disposition. Arsenic content in plasma and ultrafiltrate samples is
measured via graphite furnace (flameless) atomic absorption
spectroscopy. Measured drug concentrations are analyzed
compartmentally to obtain pharmacokinetic parameters.
Example 9
Toxicology Studies
Multiple-Dose Toxicology Studies
[0264] Further studies were performed to determine the
dose-limiting toxicity associated with the administration of
repeated doses in groups of mice of MER-1 and SGLU-1.
[0265] The results of the MER1 Multiple Dose I.V. toxicology study
evaluating 110, 120, 130, 140, and 150 mg/kg daily .times.5, are
summarized as follows: The study focused on the microscopic
examination of heart, lung liver, and kidney. Medial hyperplasia of
coronary arteries is usually a spontaneous lesion that is more
common in male mice than in female mice. Inflammatory lesions,
e.g., lymphocyte aggregates, in the kidney and liver were concluded
to be incidental findings unrelated to MER1. Hepatocyte hypertrophy
and acute necrosis of renal tubules were lesions of uncertain
significance encountered inconsistently in treated mice of both
sexes. The panlobular hypertrophy observed in males at the higher
doses was sometimes associated with a microvescicular vacuolation
suggesting possible hepatic toxicity. These animals generally were
sacrificed in extremis after a single dose. Vascular lesions in
lungs of these multi-dose mice were not consistent or striking when
present although vasculopathies were common in the single-dose
study of MER1. The tolerance of fewer doses and greater mortality
in male mice suggested that the male gender is more sensitive to
toxic effects of this compound.
[0266] The results of the SGLU-1 Multiple Dose I.V. are summarized
as follows: Five mice/sex were administered 5 daily intravenous
injections of SGLU via the tail vein at doses of 50, 100, 150, 200,
250, 300, and 350 mg/kg/day. All surviving mice were held for 28
days, sacrificed, and designated tissues collected, formalin fixed,
and examined.
[0267] Deaths occurred at 250, 300, and 350 mg/kg/day with female
mice being more susceptible than males. Microscopic observations
noted compound-related lesions in lung, liver, thymus, and testes.
The no-observable-effect level for female mice in this study is 150
mg/kg and was based on the centrilobular hypertrophy of hepatocytes
in 1/5 female mice at 200 mg/kg/day. The no-observable-effect level
(NOEL) for male mice in this study is 100 mg/kg/day and was based
on testicular seminiferous tubular degeneration in 1/5 males at 150
mg/kg/day.
Example 10
HPLC Analytical Method Development and Validation
[0268] HPLC is used in the methods development and validation for
the use of organic arsenicals. The HPLC methods include: standard
curve and linearity, reproducibility (10 injections minimum),
sensitivity (minimum quantifiable concentration; minimum detectable
concentration), accuracy (such as using three independently
prepared solutions of 0.025 mg/mL, 0.1 mg/mL, 1 mg/mL), intentional
degradation from heat, basic solutions acidic solutions and
H.sub.2O.sub.2, and peak definition for intact drug, bulk
impurities and starting materials, and degradation products. Bulk
raw drug is analyzed in a reference standard lot through HPLC
analysis of purity, loss on drying, optical rotation, melting
point, and visual appearance.
Example 11
Dosage Forms Development
[0269] The dosage of organic arsenicals are developed following the
formulation solvent system developed by the Pharmacology
Laboratory. This includes determining the stability in potential
aqueous vehicles and to filtration, selecting target concentration
for further development, testing the osmolality and pH and
adjusting if necessary, selecting package and closure
configuration, determining the thermal stability (autoclaving),
testing the visual appearance and particulate burden and
determining the target pH values and acceptable range for target
concentration.
Example 12
Clinical Trials
[0270] This example is concerned with the development of human
treatment protocols using the arsenical compounds, MER1, SGLU and
SAL-1, and compositions of the invention or the pharmaceutical
formulations thereof. These compositions are of use in the clinical
treatment of various cancers including leukemias and other forms of
solid cancers and tumors.
[0271] The various elements of conducting a clinical trial,
including patient treatment and monitoring, are known to those of
skill in the art in light of the present disclosure.
[0272] The following information is being presented as a general
guideline for use in establishing clinical trials using the
compositions of the present invention.
[0273] Candidates for the phase 1 clinical trial are patients on
which all conventional therapies have failed. Pharmaceutical
formulations of MER1, SAL-1, or SGLU-1 are administered
intravenously on an initial schedule of 5 days every 4 weeks. One
of skill in the art will appreciate that one may administer the
therapeutic formulation of the invention by any alternative route
that is suitable depending on the nature of the lesion including
administration by any method including local, regional, or systemic
administration. Oral and topical applications are also
contemplated. A composition of the present invention is typically
administered orally or parenterally in dosage unit formulations
containing standard, well known non-toxic physiologically
acceptable carriers, adjuvants, and vehicles as desired. The term
parenteral as used herein includes subcutaneous injections,
intravenous, intramuscular, intra-arterial injection, or infusion
techniques.
[0274] To monitor disease course and evaluate the anti-tumor
responses, the patients are examined for appropriate tumor markers
every month. To assess the effectiveness of the drug, the following
parameters are monitored: tumor size and/or bone marrow
infiltration of the cancer cells. Tests that are used to monitor
the progress of the patients and the effectiveness of the
treatments may include: physical exam, X-ray, blood work and other
clinical laboratory methodologies. The doses given in the phase 1
study is escalated as is done in standard phase 1 clinical phase
trials, i.e. doses will be escalated until maximal tolerable ranges
are reached.
[0275] Clinical responses may be defined by acceptable measure. For
example, a complete response may be defined by complete
disappearance of evidence of cancer cells for at least 2 months.
Whereas a partial response may be defined by a 50% reduction of
cancer cells for at least 2 months.
[0276] The clinical trials may be performed with the therapeutic
agents of the invention alone or in combination with other
anti-cancer drugs and other standard cancer therapies used in the
art. The therapeutic compositions of the invention may be delivered
to the patient before, after, or concurrently with the other
anti-cancer agents.
[0277] The typical course of treatment will vary depending upon the
individual patient and disease being treated in ways known to those
of skill in the art. For example, a patient with leukemia may be
treated in four week cycles, although longer duration may be used
if adverse effects are observed with the patient, and shorter terms
of treatment may result if the patient does tolerate the treatment
as hoped. Each cycle consists of 5 individual doses, although this
too may be varied depending on the clinical situation. Upon
election by the clinician, the regimen may be continued with 5
doses every three weeks or on a less frequent basis. Of course,
these are only exemplary times for treatment, and the skilled
practitioner will readily recognize that many other time-courses
are possible.
[0278] Patients may, but need not, have received previous chemo-,
radio- or gene therapeutic treatments. Optimally the patient
exhibit adequate bone marrow function (defined as peripheral
absolute granulocyte count of >2,000/mm.sup.3 and platelet count
of 100,000/mm.sup.3, adequate liver function (bilirubin 1.5 mg/dl)
and adequate renal function (creatinine 1.5 mg/dl).
[0279] In one embodiment, administration simply entails injection
of the therapeutic composition into the tumor. In another
embodiment, a catheter is inserted into the site of the tumor and
the cavity may be continuously perfused for a desired period of
time.
[0280] Of course, the above-described treatment regimes may be
altered in accordance with the knowledge gained from preclinical
trials. Those of skill in the art will be able to take the
information disclosed in this specification and optimize treatment
regimes based on the clinical trials described in the
specification.
Example 13
Alternate Synthesis of S-Dimethylarsinoglutathione
[0281] The following procedure describes the manner of preparation
of S-dimethylarsinoglutathione. The quantities used can be
multiplied or divided with equal success if the respective ratios
are maintained.
Dimethylchloroarsine.
[0282] Dimethylarsinic acid, (CH.sub.3).sub.2As(O)OH was supplied
by the Luxembourg Chemical Co., Tel Aviv, Israel. The product was
accompanied by a statement of its purity and was supplied as 99.7%
pure. The dimethylarsinic acid was dissolved in water-hydrochloric
acid to pH 3. A stream of sulfur dioxide was passed through this
solution for about one hour. Dimethylchloroarsine separated as a
heavy, colorless oil. The two liquid phases,
water/(CH.sub.3).sub.2AsCl were separated using a separatory
funnel. The chlorodimethylarsine was extracted into diethylether
and the ether solution was dried over anhydrous sodium sulfate. The
dried solution was transferred to a distillation flask which was
heated slowly to evaporate the ether. The remaining liquid,
dimethylchloroarsine was purified by distillation. The fraction
boiling at 106-109.degree. C. was collected. The product, a
colorless oil, displays a simple .sup.1H NMR resonance at 1.65
ppm.
S-Dimethylarsinoglutathione.
[0283] In a 500 mL flask, 7 g of glutathione was used as received
from the Aldrich Chemical Co., purity 98% and dissolved in 250 mL
of 1,2-dimethoxyethane. To this solution was added 3.3 g of
dimethylchloroarsine. This was followed by the addition of 3.5 g of
pyridine (redistilled after drying over NaOH pellets). The solution
was refluxed for one hour after which time it was stirred at room
temperature for three hours.
[0284] The desired product, S-dimethylarsinoglutathione was
separated as the pyridine hydrochloride complex. The solid was
removed by filtration and washed thoroughly with
1,2-dimethoxyethane. It was subsequently dried over anhydrous
calcium chloride in vacuo. The yield of S-dimethylarsinoglutathione
pyridine hydrochloride was 10.3 g and the melting point was
135-140.degree. C. This material was used in the biological assays
described above in examples 2 to 12.
Example 14
Pyridine Hydrochloride Free Synthesis of
S-Dimethylarsinoglutathione (GLU)
[0285] Dimethylarsinoglutathione is made using an adapted of Chen
(Chen, G. C., et al. Carbohydrate Res. (1976) 50: 53-62) the
contents of which are hereby incorporated by reference in their
entirety. Briefly, dithiobis(dimethylarsinoglutamine) is dissolved
in dichloromethane under nitrogen. Tetramethyldiarsine is added
dropwise to the solution and the reaction is stirred overnight at
room temperature under nitrogen and then exposed to air for 1 h.
The mixture is then evaporated to dryness and the residue is washed
with water and dried to give a crude solid that is recrystallized
from methanol to give S-dimethylarsinoglutathione.
Example 15
Third Synthesis of Pyridine Hydrochloride Free
S-Dimethylarsinoglutathione (GLU)
[0286] S-dimethylarsinoglutathione is made using the procedure of
Cullen et al. (J. Inorg. Biochem. (1984) 21: 179-194) the contents
of which are hereby incorporated by reference in their entirety.
Briefly, dimethylarsinic acid and glutathione are dissolved in
water under a nitrogen atmosphere and stirred. The resulting
solution is stirred for 12 h and then evaporated to dryness under
reduced pressure without heating to give a solid that is extracted
with cold methanol. The methanol solution is then evaporated to
dryness under reduced pressure and the resulting solid is
recrystallized from methanol/water, collected, and dried to give
S-dimethylarsinoglutathione.
Example 16
In Vitro Evaluation of Anti Cancer Activity of GMZ27
[0287] GMZ27, an organic arsine having the following structure
##STR15## was tested in 72 hour MTS assays against different human
acute myelocytic leukemia (AML) cell lines and it was found that
the IC.sub.50 was 0.56-0.86 .mu.M. This activity was higher than
the activity of arsenic trioxide against these cell lines (FIG.
27A). The anti-leukemic activity of GMZ27 was then evaluated in a
long-term (7 day) colony-forming assay, where cells are grown in
semi-solid medium. GMZ27 had significantly higher activity than
arsenic trioxide against both human leukemia cell lines and
leukemic cells obtained from patients with acute or chronic
leukemia (FIG. 27B).
[0288] The mechanisms of anti-cancer activity of GMZ27 and arsenic
trioxide were then compared. Arsenic trioxide (ATO) exerted its
anti-leukemic activity in cells other than APL via several
mechanisms, including induction of apoptosis, alteration in the
production of intracellular ROS resulting in the modulation of
cellular GSH redox system, cell differentiation/maturation and
possible effect on cell cycle regulation.
[0289] GMZ27 was more potent in induction of apoptosis than ATO.
Results show that it activated the mitochondrial apoptotic pathway,
as it altered mitochondrial membrane potential and cleaved caspase
9, but also by alternate, extrinsic, pathway since it cleaved
caspase 8. This resulted in the induction of caspase 3 activity,
cleavage of PARP, and binding of annexin V to the cells (FIGS. 28
and 29).
[0290] Pretreatment of leukemic cells with buthionine
sulfoximine(BSO) renders them more sensitive to GMZ27; while
pretreatment with dthiothreitol (DTT) or N-acetylcysteine (NAC),
which may increase intracellular GSH, rendered the cells less
sensitive (FIG. 30). This suggested that GMZ27, like ATO, modulates
the GSH redox system in leukemic cells, however, it did so earlier
and to a greater extent than ATO did (FIG. 31).
[0291] GMZ27, at low doses, was found to partially induce cell
differentiation/maturation as judged by the induction of CD11b
maturation marker on the surface of cells. This effect was marginal
compared with that of ATO (FIG. 32). GMZ27 had no effect on the
cell cycle progression (FIG. 33).
[0292] Toxicity of GMZ7 against healthy donor peripheral blood
mononuclear cells has been evaluated in a long-term colony forming
assay. GMZ27 was less toxic to normal cells than ATO (FIG. 34).
[0293] Studies to determine the toxicity of a single dose injection
of GMZ27 were performed in normal Swiss-Webster mice. Toxicity was
measured on the basis of mortality. It was found that the
concentration of GMZ27 that kills 50% of mice (LD.sub.50) was 100
mg/kg. In contrast, the LD.sub.50 for ATO was much lower, at only
10 mg/kg.
Example 17
Preparation of N-(2-S-dimethylarsinothiopropionyl)glycine
[0294] N-(2-mercaptopropionyl)glycine (0.02 mol, 3.264 g) was
placed in 1,2-dimethoxyethane (50 mL) and dimethylchloroarsine
(0.025 mol, 3.52 g) was added dropwise. The reaction mixture was
stirred for 4 h at room temperature. A white precipitate of
triethylamine hydrochloride salt was then separated by filtration
and the solubtion was reduced in volume by evaporation at reduced
pressure. The resulting residue was purified by column
chromatography to afford the desired product (3.5 g).
Example 18
Preparation of 2-(S-dimethylarsino)thionicotinic acid
[0295] 2-Mercaptonicotinic acid (0.02 mol, 3 g) was placed in
dichloromethane (50 mL) and dimethylchloroarsine (0.025 mol, 3.52
g) was added dropwise. The reaction was stirred at reflux for 4 h.
The dichloromethane was then removed by distillation and the
residue was dissolved in diethyl ether (50 mL) and washed with
water (3.times.). The solution was dried over Na.sub.2SO.sub.4,
filtered, and the desired product was obtained as a pale yellow
solid after concentration under reduced pressure.
Example 19
L-(+)-2-amino-3-(dimethylarsino)thio-3-methylbutanoic acid
[0296] L-(+)-2-amino-3-mercapto-3-methylbutanoic acid (0.01 mol,
1.55 g) was placed in dichloromethane (50 mL) and
dimthylchloroarsine (0.015 mol, 2.1 g) in dichlorormethane (5 mL)
was added dropwise followed by the dropwise addition of
triethylamine (1.6 g). The mixture was stirred for 4 h and the
desired product appeared as a floating white crystalline solid
after filtration of the reaction mixture. The crystalline solid was
washed with dichloromethane, ethyl acetate, and acetone
sequentially to provide the desired product (1.6 g; mp
107-109.degree. C.).
EQUIVALENTS
[0297] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, numerous
equivalents to the compounds and methods of use thereof described
herein. Such equivalents are considered to be within the scope of
this invention and are covered by the following claims. Those
skilled in the art will also recognize that all combinations of
embodiments described herein are within the scope of the
invention.
[0298] U.S. Application Ser. No. 60/346,492, filed Jan. 7, 2002 and
WO 2003/057012, filed Jan. 7, 2003 are herein incorporated by
reference in their entirety. All of the above-cited references and
publications are hereby incorporated by reference.
* * * * *