[GRAPHIC]
US005340565A
United States Patent Patent Number: 5,340,565
Pero Date of Patent: Aug. 23, 1994
TUMOR OR CANCER CELL KILLING THERAPY AND AGENTS USEFUL THEREFOR
Inventor: Ronald W. Pero, New York, N.Y.
Assignee: Oxi-Gene, Inc., New York, N.Y.
Appl. No.: 896,236
Filed: June 10, 1992
Related U.S. Application Data
Continuation of Ser. No. 89,477, Aug. 25, 1987.
Int. Cl..................................................A61K 49/00; G01N 33/15
U.S. Cl. .......................................................424/10; 424/649
Field of Search ...........................................424/10; 649; 514/619
References Cited
U.S. PATENT DOCUMENTS
5,081,153 1/1992 Pathak et al. .......................................424/649
OTHER PUBLICATIONS
White et al., "Induction Chemotherapy for Advanced Head and Neck Cancer...,"
Am. J. Clin. Oncol. (CCT), 15(1) (1992), pp. 45-55.
S. Lybak et al., "Dose schedule evaluation of metoclopramide...," Anti-Cancer
Drugs 2: 375-82 (1991).
R. J. Nelt et al., "Phamacokinetis of Non-Protein-Bound Platinum Species...,"
Cancer Treat. Rep. 63: 1515-21 (1979).
J. Hansson et al., "Cis-Diamminedichloroplatinum (II) Toxicity...," Acta
Oncologica 27: 383-92 (1988).
K.C. Micetich et al., "A Comparative Study of the Cytotoxicity...," Cancer
Research 45: 4043-47 (1985).
L.A. Zwelling et al., "DNA-Protein and DNA Interstrand Cross-Linking...,"
Cancer Research 39: 365-69 (1979).
C.A. Perez et al., "Impact of Irradiation Technique and Tumor Extent...,"
Cancer 50: 1091-99 (1982).
E. Kjellen et al., "Metoclopramide enhances the effect of cisplatin...,"
Br. J. Cancer 59: 247-50 (1989).
E. Kjellen et al., "A therapeutic benefit from combining normobaric
carbogen...," Radiotherapy and Oncology 22: 81-91 (1991).
S. Lyback, Metoclopramide: A representative of a new class of drugs for
potentiation of cytotoxicity, University of Lud, Sweden (1991), p. 115.
Primary Examiner -- Nathan M. Nutter
Attorney, Agent, or Firm -- Cooper & Dunham
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ABSTRACT
The effectiveness of cytostatic and/or cytotoxic drugs and/or radiation in the
killing of tumor and/or cancer cells is increased by the administration, along
with said drugs and radiation, of an effective activating or inhibiting amount
of a compound or agent which activates or inhibits the chromatin-bound enzyme
adenosine diphosphate ribosyl transferase (ADPRT) or the administration of an
effective intracellular free Ca++-increasing amount of a compound which induces
cellular or oxidative stress or which acts as an inhibitor or antagonist or
calmodulin or Ca++-calmodulin binding. Suitable such compounds or agents
include the phenothiazines, antihistamines, butyrophenones, cannabinoids and
corticosteriods and particularly metoclopramide when employed in combination
with cisplatin.
7 Claims, 1 Drawing Sheet
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TUMOR OR CANCER CELL KILLING THERAPY AND AGENTS USEFUL THEREFOR
This is a continuation of application Ser. No. 089,477, filed Aug. 25, 1987.
BACKGROUND OF THE INVENTION
One important strategy in designing effective cancer chemotherapeutic
drugs is defining the mechanism of cell death. Activation of the
chromatin-bound enzyme, adenosine diphosphate ribosyl transferase (ADPRT), and
the subsequent depletion of energy metabolites, such as NAD and ATP, are
involved in the suicidal response to induced cellular DNA damage that leads
eventually to cell death, Berger, N.A., J. Clin. Invest. 78: 1131-1135, 1986.
Radiation and/or most cancer therapeutic drugs induce DNA damage, and as a
consequence involve ADPRT activity as part of their cytotoxic mechanisms of
action, Huet and Laval, Int. J. Radiat. Biol. 47: 655-662, 1985.
Hence, inducers of ADPRT enhance cytotoxicity by seriously depleting
cellular energy pools in an effort to repair the potentially lethal DNA damage
induced by most chemotherapeutic drugs and/or radiation. This is true because
NAD is consumed as a co-substrate by ADPRT activity, Hayaishi and Ueda, Ann.
Rev. Biochem. 46: 96-116, 1977; Purnell et al., Biochem. Soc. Trans. 8:215-227,
1980, which is in turn induced by DNA strand breaks, Halldorsson et al., FEBS
Lett. 85: 349-352, 1978; Benjamin and Gill, J. Biol, Chem. 255:10493-10508,
1980; Cohen and Berger, Biochem. Biophys. Res. Commun. 98: 268-274, 1981. since
cellular NAD/ATP pools are coupled, then cellular energy is depleted and
cytotoxicity is enhanced. On the other hand, inhibitors of ADPRT are also
sensitizers of cytotoxicity because they prevent the repair of potentially
lethal DNA damage.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows the effect of treatment of the growth of a human squamous
cell carcinoma xenographed to nude mice with CDDP
(CiS-Diamine-Dichloroplatinum) combined with Metoclopramide.
The invention is indicated in accompanying FIG. 1 wherein data
demonstrating the effectiveness of a practice of this invention is graphically
illustrated.
SUMMARY OF THE INVENTION
This invention relates to the discovery that many compounds with
antiemetic action, such as the substituted N-tertiary amino benzamides,
phenothiazines, antihistamines, butyrophenones, cannabinoids, and
corticosteriods have properties that enhance the effectiveness of cytostatic
drugs or radiation in the killing of tumor cells. Broadly, compounds which
activate or inhibit the chromatin-bound enzyme adenosine diphosphate ribosyl
transferase ADPRT or which induce cellular or oxidative stress or which act as
inhibitors or antagonists of calmodulin or Ca++-calmodulin binding are useful
to enhance the effectiveness of cytostatic drugs or radiation in the killing of
tumor cells.
DETAILED DESCRIPTION OF THE INVENTION
There are at least 4 well known classes of inhibitors of ADPRT; namely
nicotinamide analogs, benzamide analogs, pyrazinamide analogs and purine
analogs, Sims et al., Biochem. 21: 1813-1821, 1982, Nduka et al., Eur. J.
Biochem. 105: 525-530, 1980. The common structural feature that was shown to be
of importance to maintain a high degree of inhibition of ADPRT by the analogs
of nicotinamide, benzamide and pyrazinamide, is the presence of a
ring-carboxamide group. For example, benzoic acid, 3-aminobenzoic acid,
pyrazine 1,2-dicarboxylic acid, isonicotinic acid, and 6-amino nicotinic acid
all failed to inhibit ADPRT, Sims et
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al., Biochem. 21: 1813-1821, 1982. Therefore, judging from an experimental
point of view it would not be obvious that N-tertiary amino substitutions of
the carboxamide residue of benzamide analogs would result in derivatives that
can modulate ADPRT. In fact, the only known pharmacological/biological effects
reported in the scientific literature for these analogs are as antiemetic
agents, see U.S. Pat. No. 3,177,252, and for review see also Weiss and
Weintraub, Drug Ther. 12: 167-170, 1982 and Reich, S. O., Cancer Nurs. 6:
71-73; 1983).
Nicotinamide, benzamide, 3-aminobenzamide and purine analogs, such as
theophylline and other xanthines, have been shown to be effective sensitizers
of the cytotoxic action induced by radiation and cancer chemotherapeutic drugs
in both cell culture and animal tumor model systems, Ben-Hur, E., Int. J.
Radiat. Biol. 46: 659, 1984; Utsumi and Elkind, Brit. J. Cancer (suppl. 6):39,
1984; Calcutt et al., Brit J. Cancer 24: 380, 1970; George et al., Int. J.
Radiat. Biol. 49: 783, 1986; Thraves et al., Int. J. Radiat. Oncol, Biol. Phys.
12:1541, 1986; Thraves et al., Int. J. Radiat. Res. 104:119, 1985; Thraves et
al., Int. J. Radiat. Biol. 50:961, 1986; Kumor et al., Int. J. Radiat. Biol.
47:1C3, 1985, Huet and Laval, Int. J. Radiat. Jonsson et al., Cancer Res.
45:3609, 1985; Kjelle'n et al., Acta Radiologica 25:281, 1986; Horsman et al.,
Int. J. Radiat. Oncol. Biol. Phys. 12:1307, 1986; Horsman et al., Radiat. Res.
109:479, 1987; Nduka et al., Eur. J. Biochem. 105:525, 1980; Mourelatos et al.,
Mutation Res. 121:147, 1983. However, with the exception of nicotinamide, all
of these classes of sensitizers are quite toxic by themselves thereby limiting
their potential development for use in humans. Furthermore, relatively high
doses were required for sensitizing either cells (millimolar concentration) or
tumor bearing animals 100 mg/kg) to radiation or cancer chemotherapeutic
drugs.
Nicotinamide will radiosensitize an adenocarcinoma transplanted in C3H
mice at a dose of 10 mg/kg whereas benzamide is totally ineffective in this
dose range, Kjelle'n and Pero, Eight International Symposium on
ADP-ribosylation, May 30 - June. 3, 1987, Forth Worth, Tex., Abstract 76. The
low dose effectiveness of nicotinamide has been attributed to an active
transport mechanism for which benzamide can only partially and poorly compete,
Pero et al., Eight International Symposium on ADP-ribosylation, May 30 - Jun.
3, 1987, Forth Worth, Tex., Abstract 69. However, compounds which would compete
for the nicotinamide binding and transport site and which modulate ADPRT, then
such compounds would be theoretically effective sensitizers of radio- and
chemotherapies at non-toxic low doses. Metoclopramide (4-amino-5-chloro-N-[(2-
diethylamino)ethyl]-2-methoxy-benzamide) is a drug like nicotinamide in that it
sensitizes a cancer chemotherapeutic agent at the daily low dose of 2 mg/kg.
Most chemotherapeutic agents utilized in the treatment of tumors cause,
among other disturbances, a gastrointestinal toxicity characterized in
particular by nausea and vomiting. These symptoms are important in that they
affect the patients' well-being and ability to nourish themselves and often may
exercise an influence on their acceptance or refusal to continue treatment.
Metoclopramide is well established as a successful antiemetic treatment for
chemotherapy induced nausea and vomiting, see Reich, S.D. Cancer Nurs. 6:71-73,
1983, although several other drugs with antiemetic properties, such as
phenothiazines, antihistamines, benzamide derivatives, butyrophenones,
cannabinoids, and corticosteriods have ben used, Laszlo, J. Drugs 25 (Suppl.
1):1-7, 1983. However, despite the common use of metoclopramide and other
antiemetics in chemotherapeutic treatment regimens, these drugs have never been
evaluated in relation to the clinical effectiveness of the chemotherapeutic
drug and in combination therewith.
Contrary to scientific expectations and based on benzamide analog studies
as inhibitors of ADPRT and thus sensitizers of radio- and chemo- therapies,
substitutions into the carboxamide group of benzamide, nicotinamide and
pyrazinamide analogs, do not necessarily destroy the sensitizing properties of
these compounds since metoclopramide, a polysubstituted-N-tertiary amino alkyl
benzamide, is an effective sensitizer in cancer chemotherapy, such as a
sensitizer of a cancer chemotherapeutic drug.
The following are examples of the practices of this invention.
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EXAMPLE 1
Cisplatin (cis-diamine-dichloroplatinum = CDDP) is a heavy metal complex
with alkylating properties which allow bifunctional linking to DNA. CDDP has
been used successfully as a chemotherapeutic agent to treat several types of
human cancers. Since CDDP treatment regimes induce nausea and vomiting,
metoclopramide is often co-administered therewith as an antiemetic drug. This
example demonstrates that metoclopramide not only suppresses the number of
episodes of nausea and vomiting, but it also potentiates the cytotoxic effect
of CDDP on human cancer cells, such as on a human squamous cell carcinoma (SCC)
(ABII) of the head and neck xeno-grafted to nude mice.
Two administration schedules were tested: (A) metoclopramide (2.0 mg/kg
i.p.) one hour before CDDP (7.5 mg/kg i.p.) and (B) metoclopramide (2.0 mg/kg X
3 treatment times) given separately concomitant to CDDP (7.5 mg/kg i.p.) and 24
hr. and 48 hr. after CDDP administration. In both schedules the combined
treatment was compared with CDDP alone, metoclopramide alone and with
physiologic saline treated tumor bearing animals (controls). The tumor line
used was a poorly differentiated human SSC originating from the nose. There
were n=10 animals in each group. Tumor diameters and animal weight were
recorded and plotted twice weekly for 21 days. Treatment efficacies were
compared using the area under the plotted growth curves (AUC).
There was no mortality and no weight loss of significance in any treatment
group. In neither schedule A nor B did metoclopramide alone induce any
significant reduction in AUC. CDDP alone gave a significant reduction of
AUC-values. In schedule A the addition of metoclopramide did not give any
additive effect. In schedule B metoclopramide potentiated the effect of CDDP,
which when given alone reduced AUC to 72% of control tumor growth. CDDP +
metoclopramide significantly reduced AUC to 36% of control tumor growth. The
above experiment was repeated using another human SSC (EH) transplanted in nude
mice. The tumor weights at day 21 after the initiation of the experiment are
graphically presented in FIG. 1. Likewise, a significant reduction in tumor
weight was achieved with a combined treatment of CDDP + metoclopramide. These
data show that metoclopramide sensitizes or enhances the cytotoxic action of
CDDP against two different human SSC lines carried in nude mice, and at a dose
currently being administered as an antiemetic agent to patients receiving
cancer chemotherapy.
As mentioned above, inhibitors of ADPRT enhance the cytotoxicity induced
by radiation and cancer chemotherapeutic drugs. However, it is also important
to appreciate that DNA strand damaging agents induce ADPRT activity and DNA
damage is a target site for the biological induction of cytotoxicity, Durkacz
et al., Nature 296: 593-596, 1980, and as cited above. Therefore, both
inhibitors and inducers of ADPRT are potential sensitizers of the cytotoxic
action of drugs, e.g. (A) inhibitors because they prevent the removal of
potentially lethal DNA damage of ADPRT directed DNA repair mechanisms and (B)
inducers because they enhance the production of drug- or radiation-induced DNA
damage by altering the endogenous cellular mechanisms that lead to DNA damage
and the subsequent activation of ADPRT. The following example presents one such
mechanism of endogenous DNA damage induction valid in general for many of the
drugs with antiemetic properties.
The free cytosolic level of Ca++ is known to be a critical event in the
mechanism of cytotoxicity, Trump and Berezesky, Role of Sodium and Calcium
Regulation in Toxic Cell Injury, in Drug Metabolism and Drug Toxicity, J.R.
Mitchell and M.G. Horning (eds), Raven-Press, New York, pp 261-300, 1984, and
agents that induce oxidative stress increase intracellular free Ca++ which is,
in turn, modulated by the Ca++ binding protein calmodulin, Mirabelli et al., J.
Biochem. Toxicol. 1: 29-39, 1986; and Means and Dedman, Nature 285: 73-77,
1980. Hence, antagonists of Ca++-calmodulin binding or agents that increase
free cytosolic Ca++, such as oxygen radicals produced by oxidatively stressing
the cell, would be expected to increase DNA damage, thereby activating ADPRT
and inducing cytotoxicity by a mechanism different from that associated with an
inhibition of ADPRT and DNA repair, Schraufstatter et al., J. Clin. Invest.
76:1131-1139, 1985, and Schraufstatter et al., J. Clin. Invest. 77:1312-1320,
1986.
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The following Example II establishes that many antiemetic agents can
modulate cellular Ca++ homeostasis, activate ADPRT, induce cytotoxicity in
themselves and thus possess the properties to sensitize or enhance or increase
cytotoxicity when used in combination with radiation and/or cancer chemotherapy
drugs. Although some antiemetic agents are known to antagonize Ca++-calmodulin
binding, Hidaka H. and Hartshorne D.J. (eds) Calmodulin Antagonists and
Cellular Physiology, Academic Press, Inc. New York, pp. 1-543, 1985), they are
not known to induce ADPRT or to enhance cytotoxicity.
EXAMPLE II
Human mononuclear leukocytes (HML) were isolated by Isopaque-Ficoll
gradient centrifugation from heparinized peripheral blood samples as already
described (Boyum, A., Scand. J. Clin. Lab. Invest. 21 (Suppl. 7):7, 1968. The
HML were adjusted to 1 X 106 cells per ml of Eagles minimum essential medium
and cultured at 37(degree) C. for 30 min in the presence or absence of the
indicated doses of the compounds shown in accompanying Table 1. Either
physiologic saline or 95% ethanol 0.5%, v/v) were used as co- solvents.
Cytotoxicity was assessed by trypan blue exclusion either after the 30 min
incubation period or after 18 hr incubation at 37(degree) C. of parallel
cultures as already described, Pero et al., Mutation Res. 83:271-289, 1981.
ADPRT activity was always estimated after the 30 min exposure and incubation in
permeabilized cells as described previously, Pero et al., Chem. Biol.
Interactions 47:265-275, 1983. Briefly, HML were permeabilized, exposed to 250
uM NAD tritium-labelled in the adenine moiety (20-25 Ci/mMol, Amersham, diluted
875:1 with cold NAD) for 15 min at 30(degree) C., and the protein-bound
ADP-ribose collected onto nitrocellulose filters following precipitation with
10% trichloroacetic acid (TCA). The data were recorded as cpm TCA precipitable
[3H]NAD per 1 X 106 cells.
W-7, see footnote to Table 1, is a well characterized calmodulin
antagonist which has an IC50 does of around 50uM whereas W-5, a closely related
structural analog, is inactive at 50 uM and it has an IC50 of about 250 uM
Hidaka et al, Proc. Natl. Acad. Sci. U.S.A. 78:4354-4357, 1981. These two
compounds have been used effectively to distinguish calmodulin modulated
biological events, e.g. inhibition of cell proliferation, phosphodiesterase and
myosin light chain kinase. Hence, W-7 and W-5 were used to determine the effect
of calmodulin mediated cellular events on ADPRT activity and cytotoxicity. The
data in accompanying Table 1 clearly show that W-7 induces ADPRT activity and
this effect is paralleled by an increase in cytotoxicity. No such effects were
observed with W-5, indicating that Ca++-calmodulin antagonism is an important
endogenous mechanism for mediating cytotoxic responses and cytotoxicity can be
induced by agents that antagonize Ca++- calmodulin binding.
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TABLE I
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Activation of ADPRT and resultant cytotoxicity induced by
agents that modulate Ca++ homeostasis in HML.
-------------------------------------------------------------------------------
% Dead Cells(a)
Concentration ADPRT ----------------------
Agents (uM) Activity(a) 30 min 18 hr
- --------------------------------------------------------------------------------
(1) Controls 0 385 less than 5% less than 5%
0 350 less than 5% less than 5%
(2) W-7(b) 50 750 10% --
100 910 25% --
200 1480 90% --
(3) W-5(c) 50 395 less than 5% 5%
100 415 less than 5% 5%
200 425 7% --
(4) H2O2 100 1800 5% 40%
300 2700 5% 41%
500 2900 7% 55%
1000 3000 12% 71%
(5) Metoclopramide(d) 500 530 7% 8%
2000 703 13% 29%
5000 950 10% 58%
10000 870 22% 88%
(6) Chlorpromazine(e) 100 1508 50% --
500 890 100% --
(7) Trimeprazine(f) 100 639 7% --
500 571 95% --
(8) Dixyrazine(g) 100 385 13% 78%
500 850 79% 100%
(9) Haloperidol(h) 100 655 6% --
500 746 60% --
(10) Moperone(i) 100 529 5% --
500 712 7% --
1000 1112 26% 100%
a The average of duplicate determinations are presented
b W-7 = N-(-6-aminohexyl)-5-chloro-1-naphthalenesulfonamide
c W-5 = N-(-6-aminohexyl)-naphthalenesulfonamide
d Metoclopramide = 4-amino-5-chloro-N-[C2-diethylamino)ethyl]-
2-methoxybenzmide
e Chlorpromazine = 2-chloro-N, N-dimethyl - 10H-phenothiazine-10-propanimine
piperazinyl]ethoxy]-ethanol
h Haloperidol = 4-[4(4-chlorophenyl)-4-hydroxy-1-piperidinyl]-1-
(4-fluorophenyl)-1-butanone
i Moperone = 1-(4-fluorophenyl))-4-[4-hydroxy-4(4-methyl phenyl)-
1-piperidiayl]-1-butanone
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The importance of cellular Ca++ homeostasis in the induction
of ADPRT and cytotoxicity is further supported by the data recorded for H2O2 in
Table 1. H2O2 is well known to induce a Ca++ efflux from plasma membranes and
mitochondria thus elevating intercellular free Ca++, imbalancing Ca++
homeostasis and inducing cytotoxicity, Mirabelli, et al, J. Biochem. Toxicol.
1:29-39, 1986. Again the data clearly indicate that H2O2 induces ADPRT which is
paralleled by increases in interphase cell death, although the cytotoxicity is
more evident after 18 hr incubation than immediately after exposure (i.e. 30
min). The data confirm thatgents which interfere with Ca++ homeostasis can also
enhance cytotoxicity, and therefore these types of compounds are potential
sensitizers of radiation and chemotherapeutic drugs.
The data reported in Table 1 on metoclopramide confirm this hypothesis.
The data reported in Example I demonstrate that metoclopramide is a good
sensitizer of the chemotherapeutic drug, cisplatin, and Table 1 establishes
that metoclopramide activates ADPRT and induces cytotoxicity endogenously
without the addition of other cytostatic agents. Since the other classes of
agents presented in Table 1 are known modulators of Ca++ homeostasis and they,
in turn, gave similar patterns of induction of ADPRT and cytotoxicity, it is
concluded that these common biochemical/biological effects are characteristic
of a new class of sensitizers of radiation and chemotherapeutic drugs, all as
described herein. These common biochemical/biological effects are
characteristic of a new class of sensitizers of radiation and chemotherapeutic
drugs and are totally unexpected since metoclopramide is a benzamide derivative
and benzamide derivatives have previously only been shown to sensitize
cytostatic agents by inhibition of ADPRT. Consequently, Example II reveals that
many antiemetic agents possess the common property of inducing ADPRT and
cytotoxicity presumably via modulation of Ca++ homeostasis thus giving these
agents the potential to sensitize the cytostatic action of other agents, such
as radiation and chemotherapeutic drugs.
Compositions useful in the practices of this invention include in their
make-up a cytotoxic or cytostatic compound or agent and a compound or agent
which activates or inhibits ADPRT and/or which induces cellular or oxidative
stress, such as a compound which produces or yields cellular H2O2 or which acts
as an inhibitor or antagonist of calmodulin or Ca++-calmodulin binding.
Useful cytotoxic or cytostatic compounds or agents include, in addition to
cisplatin, the other useful chemotherapeutic cytotoxic agents employed in
cancer chemotherapy, such as adriamycin, 5-fluorouracil, methotrexate, cytoxan,
vincristine, daunomycin, BCNU, CCN, MeCCNU and others.
Useful compounds or agents which activate or inhibit ADPRT or which induce
cellular or oxidative stress or which act as inhibitors or antagonists of
calmodulin of Ca++-calmodulin binding include metoclopramide, chlorpromazine,
trimeprazine, dixyazine, halperidol, moperone, W-7 and W-5. The recently
discovered parathyroid hormone factor, PTH-like peptide, a factor which induces
high blood levels of calcium, see Science, Vol. 237, pages 363,364, July 24,
1987, also is usefully employed in compositions of and in the practices of this
invention.
As indicated hereinabove, the compounds or agents which activate or
inhibit ADPRT or which induce cellular or oxidative stress or which act as
inhibitors or antagonists of calmodulin or Ca++-calmodulin binding and the
associated cytotoxic or cytostatic agent employed in combination therewith may
be administered to the human patient undergoing treatment simultaneously,
separately or combined in the same composition, or substantially
simultaneously, such as one compound or agent before the other or within the
period of time of 1- 120 minutes, more or less, after administration of the
first compound or agent of the combination. These administrations, usually
intravenously, may be continued over an extended period of time of days, weeks
or months.
Compositions in accordance with the practice of this invention which are
usefully employed for inhibiting, controlling or reducing in humans the growth
of human tumor or cancer cells by administration alone or in combination with
radiation therapy contain an effective amount of a cytotoxic or cytostatic
compound or agent in the range 0.1-20 parts by weight or mols and an effective
amount of a compound or agent which
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activates or inhibits the chromatin-bound enzyme adenosine diphosphate ribosyl
transferase ADPRT or which induces cellular or oxidative stress or which acts
as an inhibitor or antagonist of calmodulin or Ca++-calmodulin binding in the
range 0.1-20 parts by weight or mols. The above-mentioned amounts of these
compounds present in the compositions of this invention are relative to each
other, i.e. for every 0.1-20 parts by weight or mols of one compound there is
present a corresponding amount in the range 0.1-20 parts by weight or mols of
the other compound.
Such compositions are administered by the usual or conventional
techniques, e.g. orally, intramuscularly, intravenously or subcutaneously,
usually depending upon the character of the cytotoxic or cytostatic compound
present in the composition and the nature, amount and location of the tumor or
cancer cells being treated. The amount or dosage of such compositions
administered also depends up on the character of the cytotoxic or cytostatic
compound in the composition as well as the character of the other compound
making up the composition of this invention, the amount and/or nature of the
tumor or cancer cells being treated and the extent or degree of inhibition of
the tumor or cancer cells desired.
Although compositions in accordance with this invention usually contain a
compound which activates or inhibits ADPRT in an amount in the range 0.1-20
parts by weight or mols, compositions which contain such compounds in an amount
outside this range are also useful. For example, compositions which contain
compounds which activate ADPRT in an amount in the range 0.01-12 parts by
weight or mols or, for example, an amount in the range 0.5-2.0, are also
useful. Compositions which contain these same amounts or ratios of the other
compound, i.e. compounds which induce cellular or oxidative stress which act as
inhibitors or antagonists of calmodulin or Ca++-calmodulin binding are also
useful in the practices of this invention.
Although emphasis in the disclosures of this invention has
been placed on the use of these compositions for inhibiting in humans the
growth of tumor or cancer cells, compositions of this invention which contain
substantially only a compound or agent which induces cellular or oxidative
stress or which acts as an inhibitor or antagonist of calmodulin or
Ca+++-calmodulin binding, are also useful. For example, such special
compositions in accordance with this invention which contain a compound or
agent which induces cellular or oxidative stress or which acts as an inhibitor
of calmodulin or Ca++-modulin binding without a cytostatic or cytotoxic drug or
with the substantial absence therein of a cytostatic and/or cytotoxic drug, are
useful in the treatment of human patients undergoing radiation therapy for
inhibiting the growth or tumor or cancer cells.
Indeed, in accordance with yet another embodiment of the practices of this
invention such compositions which do not contain a cytostatic and/or cytotoxic
drug are useful in the long term treatment of humans for the prevention of
caner. Such long term treatment would extend over a period of many months and
years, with regular small dosages to the human patient of a composition in
accordance with this invention which contains a compound or agent which induces
cellular or oxidative stress or which acts as an inhibitor or antagonist of
calmodulin or Ca++-calmodulin binding. Such compositions when employed for long
term treatment for the prevention of cancer in humans might also contain a
small clinically ineffective amount of a cytotoxic or cytostatic drug. This
aspect of this invention, however, for the prevention of human cancer is
presently less preferred than the use of compositions which contain
substantially only a compound or agent which induces cellular or oxidative
stress or which acts as an inhibitor or antagonist of calmodulin or Ca++-
calmodulin binding.
As will be apparent to those skilled in the art in the light
of the foregoing disclosures, many modifications, substitutions and alterations
are possible in the practices of this invention without departing from the
spirit or scope thereof.
What is claimed is:
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1. A method of inhibiting or killing tumor or cancer cells in
a human patient which comprises treating the patient with a chemotherapeutic
agent or radiation while administering to the patient an N-substituted
benzamide, that can activate ADPRT, in an amount effective to increase the
cytotoxicity of the chemotherapeutic agent or the radiation.
2. A method according to claim 1, which comprises treating the patient
with radiation while administering to the patient an N-substituted benzamide,
that can activate ADPRT, in an amount effective to increase the cytotoxicity of
the radiation.
3. A method according to claim 2, wherein said N-substituted benzamide,
that can activate ADPRT, is metoclopramide.
4. A method according to claim 1, which comprises treating the patient
with a chemotherapeutic agent while administering to the patient an
N-substituted benzamide, that can activate ADPRT, in an amount effective to
increase the cytotoxicity of the chemotherapeutic agent.
5. A method according to claim 4, wherein said N-substituted benzamide,
that can activate ADPRT, is metoclopramide.
6. A method of inhibiting or killing tumor or cancer cells in a human
patient which comprises treating the patient with a chemotherapeutic agent or
radiation while administering to the patient, in combination, nicotinamide and
an oxidative stressing agent in amounts that, in combination, are effective to
increase the cytotoxicity of the chemotherapeutic agent or the radiation.
7. A method of inhibiting or killing tumor or cancer cells in a human
patient which comprises treating the patient with a chemotherapeutic agent or
radiation while administering to the patient (a) an N-substituted benzamide,
that can activate ADPRT, in an amount effective to increase the cytotoxicity of
the chemotherapeutic agent or the radiation or (b) in combination, nicotinamide
and an oxidative stressing agent in amounts that, in combination, are effective
to increase the cytotoxicity of the chemotherapeutic agent or the radiation.
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406050.1