WO2013152342A1

WO2013152342A1 - Anti-cancer mtor inhibitor and anti-androgen combination

Info

Publication number: WO2013152342A1
Application number: PCT/US2013/035550
Authority: WO
Inventors: Sharon M. Barr; Matthew E. O'CONNOR
Original assignee: OSI Pharmaceuticals, LLC
Priority date: 2012-04-06
Filing date: 2013-04-08
Publication date: 2013-10-10

Abstract

Methods and compositions for treating cancer comprising administering to a patient a combination regimen comprising OS I - 027 and an androgen receptor antagonist.

Description

ANTI-CANCER MTOR INHIBITOR AND ANTI-ANDROGEN COMBINATION

FIELD AND BACKGROUND

The present invention pertains to anti-cancer therapies, certain chemical compounds and anti-cancer agents, formulations and drug products, and methods of treating tumors and tumor metastases, including with rational therapeutic combinations.

The present invention pertains in part to prostate cancer, which is most common cancer in men. Prostate cancer is a complex disease primarily characterized by dependence on androgen receptor (AR) signaling. Androgen deprivation therapy is efficacious, however prostate tumors which initially respond to castration or androgen antagonists eventually progress to castration resistance. These castration-resistant tumors may develop hypersensitivity to low levels of androgens or may adapt to rely on alternate signaling pathways such as the PI3K/mTOR axis. Deregulation of the PI3K/mTOR axis is a feature of prostate cancer, as evidenced by the fact that 40% of primary and 70% of metastatic prostate tumors exhibit loss of the tumor suppressor PTEN.

In this regard, the following publications are noted: WO2010/044893 to Abbinghaus;

US201 1/0003839; US201 1/0224223 to Shokat et al.; Attard et al., Clin. Cancer Rsch., 17(7), 1649-1657 (201 1 ); Carver et al., Cancer Cell, 19, pp. 575-586 (201 1 ); Evans et al., PNAS, 108(23), 9578-9582 (201 1 ); Ghosh, Asian J. Andrology, 1 -2 (online 26 Sept 201 1 ); Guertin et al., Cancer Cell, 15, 148-159 (2009); Kaarbo et al., Cell Oncol., 32(1-2), 1 1 -27 (2010); Larrson et al., Curr. Med. Chem., 18(29), 4440-4453 (201 1 ); Massard et al., Clin. Cancer Rsch., 17(12), 3876-3883 (201 1 ); Mulholland et al., Cancer Cell, 19, 792-804 (201 1 ); Taplin et al., J. Clin. Oncol., 21 (14), 2673-2678 (2003); Taylor et al., Cancer Cell, 18, 1 1 -22 (2010); Thomson et al., Cancer Cell, 19, pp. 697-699 (201 1 ); Turney et al., BJU Int'l, 107, 1488-1499 (2010); Vasaitis et al., Future Med. Chem., 2(4), 667-680 (2010); Wang et al., Oncogene, 27, 7106-71 17 (2008); Wu et al., Anticancer Res., 30(10), 3895-3901 (2010). All of the foregoing are incorporated by reference in their entireties.

SUMMARY

The present invention provides methods of treating prostate cancer, including castration-resistant prostate cancer; pharmaceutical compositions and kits.

In some aspects, the invention includes a method of treating prostate cancer in a human patient in need thereof, comprising administering an effective regimen comprising OSI-027 and an androgen receptor antagonist.

In some aspects, the prostate cancer is metastatic castrate-resistant prostate cancer. In some aspects, the prostate cancer is asymptomatic castrate-resistant prostate cancer.

In some aspects, the androgen antagonist is a non-steroidal agent. In some aspects, the androgen antagonist is selected from bicalutamide, flutamide, nilutamide, or abiraterone.

In some aspects, the androgen antagonist is MDV3100. In some aspects, the MDV3100 is administered in an amount of about 20-500 mg/day, or about 160mg per day.

In some aspects, the androgen antagonist is A51 or A52. In some aspects, the A51 or A52 is administered in an amount of about 20-500 mg/day, or about 100-200 mg per day.

In some aspects, the prostate cancer is resistant to single agent bicalutamide, flutamide, or nilutamide.

In some aspects, the prostate cancer is resistant to MDV3100 when administered as a single agent.

In some aspects, the prostate cancer is resistant to A51 or A52 when administered as a single agent.

In some aspects, the prostate cancer is resistant to OSI-027 when administered as a single agent.

In some aspects, the OSI-027 is administered in an amount of about 30-200 mg QD on days of administration.

In some aspects, the patient survives for at least about 16, 18, 20, 22, 24, 30, or 36 months.

In some aspects, the invention includes a method of treating a human patient having a tumor or tumor metastasis that has acquired resistance to androgen receptor antagonist therapy, comprising administering an effective regimen comprising OSI-027 and an androgen receptor antagonist. In some aspects, the cancer is breast or endometrial cancer.

In some aspects, the invention includes a method of synergistically inhibiting castration resistant prostate cancer cell proliferation comprising treating castration resistant prostate cancer cells with OSI-027 and an androgen antagonist. In some aspects, the androgen antagonist is MDV3100. In some aspects, the androgen antagonist is A51 or A52.

In some aspects, the invention includes the use of OSI-027 in the manufacture of a medicament for treating prostate cancer in combination with an androgen antagonist. In some aspects, the androgen antagonist is MDV3100. In some aspects, the androgen antagonist is A51 or A52.

In some aspects, the invention includes a pharmaceutical composition comprising OSI-

027 and MDV3100 and at least one pharmaceutically acceptable carrier.

In some aspects, the invention includes a pharmaceutical composition comprising OSI- 027 and A51 or A52 and at least one pharmaceutically acceptable carrier.

In some aspects, the invention includes a kit comprising at least one container, compositions comprising OSI-027 and MDV3100, and a package insert comprising instructions for use to treat prostate cancer. In some aspects, the invention includes a kit comprising at least one container, compositions comprising OSI-027 and A51 or A52, and a package insert comprising instructions for use to treat prostate cancer.

All publications, including patent documents, referred to herein are incorporated by reference in their entireties even where not specifically stated for a given document.

BRIEF DESCRIPTION OF DRAWINGS

Figs. 1A-1C. Prostate cancer cell lines exhibit differential sensitivity to OSI-027, bicalutamide and MDV3100. A panel of prostate cancer cell lines was treated with varying doses of bicalutamide (Fig. 1A), MDV3100 (Fig. 1 B) or OSI-027 (Fig. 1C) as single agents, and cell viability was measured at 96 hours after treatment. The effect of each drug on cell proliferation is shown graphically relative to the vehicle-treated control and is expressed as a fraction of 1. Those cell lines described as androgen insensitive are noted (Fig. 1 C). OSI-027 is equally potent in androgen-sensitive and androgen-insensitive cell lines.

Fig. 2. Co-inhibition of the PI3K mTOR and AR signaling axes cooperates to induce cell death. The effect of drug treatment on key cellular signaling pathways in LnCap cells is shown. Lysates of cells treated with DMSO (vehicle control), 10 μΜ OSI-027, 100 nM rapamycin, 1 μΜ BKM120 (known PI3K inhibitor, see ACS Med. Chem. Lett., 2, 774-779 (201 1 )), 10 μΜ MDV3100, or combinations of these were resolved by SDS PAGE. The effect on expression and phosphorylation of key signaling effectors was measured by western blot. Representative images of multiple western blots are shown for the following: total expression Her2, Her3 and androgen receptor, cleaved Parp as a measure of cellular apoptosis, phospho-Akt (S473) and Phospho-PRAS40 as measures of Akt activation and signaling in the mTORC2 axis, Phospho- S6Kinase and phospho-S6 protein as measures of mTORCI signaling. Total Akt levels and Beta-actin were measured to confirm that variations in phospho-protein levels were not attributable to variations in total protein expression.

Figs. 3A-3E. mTOR inhibition sensitizes cells to the effects of bicalutamide or MDV3100. The effect of varying doses of bicalutamide alone (Fig. 3A) or MDV3100 alone (Fig. 3C) on cellular proliferation is shown by the dose response curve with closed circles. In each figure the dashed line denotes the prediction for the effect of the combination of either drug with OSI-027 if the two drugs were purely additive, as determined by the Bliss algorithm for additivity. The experimental result for the combination of varying doses of bicalutamide or MDV3100 and OSI-027 is shown by the dose response curve with the open circles (Figs. 3B, D). The effect of the combination of the PI3K inhibitor, BKM120, combined with the androgen receptor antagonist MDV3100 is shown in Fig. 3E. The combination of OSI-027 with bicalutamide (Fig. 3B) or MDV3100 (Fig. 3D) synergistically induces apoptosis in LnCap cells. Apoptosis, as determined by induction of caspase 3/7 activity, was measured 48 hrs after treatment. Apoptosis is expressed as the fold increase in caspase activity relative to DMSO- treated cells. The effect of OSI-027 alone on caspase 3/7 activity is shown by the dose response curve with the closed circles. The mathematical prediction for the combination of OSI- 027 and bicalutamide or MDV3100, as described above, is shown by the dashed line. The experimental result for the combination of varying doses of OSI-027 and bicalutamide or MDV3100 on cellular apoptosis is shown by the dose response curve with open circles.

DETAILED DESCRIPTION

As noted above, castration-resistant prostate tumors may develop hypersensitivity to low levels of androgens or may adapt to rely on alternate signaling pathways such as the PI3K/mTOR axis. Deregulation of the PI3K/mTOR axis is a feature of prostate cancer, as evidenced by the fact that 40% of primary and 70% of metastatic prostate tumors exhibit loss of the tumor suppressor PTEN. Not being bound by any theory, it was hypothesized according to this invention, that cross-talk between these key signaling networks may influence tumor cell survival. The effects of OSI-027 as monotherapy and combined with MDV3100 or bicalutamide were evaluated. To better understand the specific role of mTOR complexes in this signaling cross-talk, rapamycin, an allosteric mTORCI inhibitor, and BKM120, a selective PI3K inhibitor, were also evaluated.

The invention provides methods of treating abnormal cell growth of prostate cancer cells by treating with an mTOR inhibitor and an androgen receptor antagonist ("ARA") according to the invention.

In some aspects of the invention, prostate tumor cells that may be relatively insensitive or refractory to an ARA single agent treatment can be sensitized by the addition of a dual mTORC1/C2 inhibitor. Accordingly, apoptosis can be induced and proliferation inhibited. The combination can be additive or synergistic.

In some aspects of the invention, an ARA is administered to a prostate cancer patient as part of a treatment regimen that includes a dual mTORC1/C2 inhibitor, such as but not limited to OSI-027. Other additional active agents may also be administered.

Dosing and administration can follow any of a variety of approaches, including daily or intermittent dosing of the mTOR inhibitor. The active agents can be administered together or separately, on the same days, or on different days.

Patients and Indications

In some embodiments, the compositions and methods of the present invention are used to treat any androgen receptor-dependent cancer in a human patient. The type or stage of the cancer is not limited. In some embodiments, the compositions of the present invention are used to treat prostate cancer in a human patient. In some embodiments, the cancer is one in which androgen receptor signaling and PI3K/mTOR axis signaling are activated or highly activated. In some embodiments, the cancer is breast cancer or endometrial cancer. The stage of the cancer is not limited.

In some embodiments, ARA treatment is not or is no longer effective against the prostate cancer in question, i.e., the tumor or tumor metastasis cells are relatively insensitive or refractory to such treatment. Such aggressive forms of cancer that can be termed refractory, androgen independent, or castration resistant, are generally referred to herein as castration resistant. Castration resistant prostate cancer can be asymptomatic or metastatic.

In some embodiments, the cancer cells, tumor, or tumor metastasis is relatively insensitive or refractory to mTOR inhibitor treatment as a single agent, such as a selective dual mTORC1/C2 inhibitor, such as but not limited to OSI-027 treatment.

Such prostate or breast cancers may be treated according to the invention by administering a regimen comprising an mTOR inhibitor and an ARA.

The active agents administered according to the invention are an mTOR inhibitor and an ARA, optionally in conjunction with additional active agents. mTOR Inhibitors

In some embodiments, the mTOR inhibitor is any dual ATP-competitive mTORC1/C2 inhibitor that is or becomes approved for use in humans by a regulatory authority.

Examples of mTOR inhibitors useful in the invention described herein include those disclosed and claimed in US 2007/01 12005, a series of compounds that inhibit mTOR by binding to and directly inhibiting both mTORCI and mTORC2 kinases. In some embodiments, the mTORC1/C2 inhibitor is irans-4-[4-amino-5-(7-methoxy-1 /-/-indol-2-yl)imidazo[5,1 - f\[\ ,2,4]triazin-7-yl]cyclohexanecarboxylic acid (also known as OSI-027). Preferred salts of OSI-027, including a tromethamine salt, are described in WO 2009/1 17482. As used herein, reference or recitation of "OSI-027" includes any salts, solvates, hydrates, and other physical forms, crystalline or amorphous, thereof. OSI-027, which is a selective orally active dual inhibitor of the catalytic activities of both mTORCI and mTORC2, is presently in clinical development. OSI-027 can be prepared according to US 2007/01 12005, Example 258.

In some embodiments, an mTORCI and C2 inhibitor is OXA-01 . Inhibition of mTOR by OXA-01 (also known as OSI-950).

In some embodiments, the rmTOR inhibitor can be as described in Feldman et al., PLoS Biol., 7(2): e1000038. doi: 10.1371 /journal. pbio.1000038 (2009), or can be PP-242, PP-30, or derivatives thereof.

Other dual inhibitors according to the invention include AZD8055, INK-128, Torin-1 , and WYE-132. Other agents include GSK-2126458. Other inhibitors are described in: US 2010/0048547; WO2010/006072; US 2009/0312319; US 2010/0015140; US 2007/0254883; US 2007/0149521 ; Drug Disc. Today Ther. Strateg., 6(2): 47-55 (2009).

Other agents can be used rationally as appropriate to supplement the multitarget approach of the present invention. The skilled artisan will understand how to profile a compound for potential mTORd and C2 activity.

As used herein, reference or recitation of an active agent includes any suitable salts, solvates, hydrates, and other physical forms, crystalline or amorphous, thereof.

Androgen Antagonists

In some embodiments, the ARA is any antiandrogen agent that is or becomes approved for use in humans by a regulatory authority. In some embodiments, the ARA is approved for use in prostate cancer. In some embodiments, the ARA is nonsteroidal.

In some embodiments, the ARA is MDV3100. MDV3100 is the compound, currently in late stage clinical development, that can be named as 4-(3-(4-cyano-3-(trifluoromethyl)phenyl)- 5,5-dimethyl-4-oxo-2-thioxoimidazolidin-1 -yl)-2-fluoro-N-methylbenzamide. MDV3100, its preparation, and uses thereof are described in US Pat. No. 7709517; Jones et al., Science, 324(5928), 787-790 (2009), which are incorporated herein by reference in their entireties.

In some embodiments, the ARA is A51 or A52. US201 1/003839 to Jung et al., which is incorporated herein by reference in its entirety, discloses the compounds A51 and A52 and methods of preparing and using the compounds. A51 is a chemical compound that can be named as 5-(8-oxo-6-thioxo-5-(4-methylphenyl)-5,7-diazaspiro[3.4]oct-7-yl)-3- trifluoromethylpyridine-2-carbonitrile. A52 is a chemical compound that can be named as 4-[7- (6-cyano-5-trifluoromethylpyridin-3-yl)-8-oxo-6-thioxo-5,7-diazaspiro[3.4]oct-5-yl]-2-fluoro-N- methylbenzamide. A52 is also known as ARN-509. See Cancer Res., 72(6), 1494-503 (Mar. 15, 2012).

In some embodiments, the ARA is orteronel (TAK-700), a CYP-17 inhibitor affecting androgen synthesis, abiraterone, a CYP-17 inhibitor affecting androgen synthesis; TOK-001 , a CYP17 inhibitor with AR antagonistic activity; N/124-1 , a CYP17 inhibitor with AR antagonistic activity; ARN-509 an anti-androgen that is a structural analog of MDV3100 optimized for sensitivity to prostate cancers with overexpressed AR; ketoconazole, an cytochrome P450 and 17,20-lyase inhibitor and androgen receptor antagonist; BMS-641988, an androgen antagonist.

In some embodiments, the ARA is selected from bicalutamide (Casodex), flutamide (Eulexin), abiraterone (Zytiga), or nilutamide (Nilandron), which are commercially available.

In some embodiments, the ARA may be used in conjunction with an effective or approved luteinizing hormone-releasing hormone (LHRH) analog, such as leuprolide, buserelin, nafarelin, histrelin, goserelin, deslorein, or triptorelin. These agents are commercially available.

In some embodiments, still additional active agents may be included in the cancer treatment according to the invention.

Pharmaceutical Compositions and Kits

In some aspects of the invention, the active agents can be coformulated or separately formulated.

The above-described pharmaceutical compositions include compositions suitable for oral, rectal, topical, and parenteral (including subcutaneous, intramuscular, and intravenous) administration, although the most suitable route in any given case will depend on the particular host and nature and severity of the conditions for which the active ingredient is being administered. The pharmaceutical compositions may be conveniently presented in unit dosage form and prepared by any of the methods well known in the art of pharmacy.

The active ingredients of the pharmaceutical compositions can be combined in intimate admixture with a pharmaceutical carrier according to conventional pharmaceutical compounding techniques. The carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral (including intravenous). Thus, the pharmaceutical compositions of the present invention can be presented as discrete units suitable for oral administration such as capsules, cachets, or tablets each containing a predetermined amount of the active ingredient. Further, the compositions can be presented as a powder, as granules, as a solution, as a suspension in an aqueous liquid, as a non-aqueous liquid, as an oil-in-water emulsion, or as a water-in-oil liquid emulsion. In addition to the common dosage forms set out above, the active ingredients of the composition, or a pharmaceutically acceptable salt thereof, may also be administered by controlled release means and/or delivery devices. The compositions may be prepared by any of the methods of pharmacy. In general, such methods include a step of bringing into association the active ingredient with the carrier that constitutes one or more necessary ingredients. In general, the compositions are prepared by uniformly and intimately admixing the active ingredient with liquid carriers or finely divided solid carriers or both. The product can then be conveniently shaped into the desired presentation.

The pharmaceutical carrier employed can be, for example, a solid, liquid, or gas. Examples of solid carriers include lactose, terra alba, sucrose, talc, gelatin, agar, pectin, acacia, magnesium stearate, and stearic acid. Examples of liquid carriers are sugar syrup, peanut oil, olive oil, and water. Examples of gaseous carriers include carbon dioxide and nitrogen.

A tablet containing the composition of this invention may be prepared by compression or molding, optionally with one or more accessory ingredients or adjuvants. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as powder or granules, optionally mixed with a binder, lubricant, inert diluent, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine, a mixture of the powdered compound moistened with an inert liquid diluent. Each tablet preferably contains from about 0.05 mg to about 5 g of the active ingredient and each cachet or capsule preferably containing from about 0.05 mg to about 5 g of the active ingredient.

A formulation intended for the oral administration to humans may contain from about 0.5 mg to about 5 g of active agent, compounded with an appropriate and convenient amount of carrier material which may vary from about 5 to about 95 percent of the total composition. Unit dosage forms will generally contain between from about 1 mg to about 2 g of the active ingredient, typically 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 800 mg, or 1000 mg.

In addition to the aforementioned carrier ingredients, the pharmaceutical formulations described above may include, as appropriate, one or more additional carrier ingredients such as diluents, buffers, flavoring agents, binders, surface-active agents, thickeners, lubricants, preservatives (including anti-oxidants) and the like. Furthermore, other adjuvants can be included to render the formulation isotonic with the blood of the intended recipient. Compositions may also be prepared in powder or liquid concentrate form.

In some embodiments, there is provided a kit of parts comprising a container, the active agents, and a package insert comprising instructions for use of the kit to treat a tumor or tumor metastasis condition. Methods of Use and Results The invention includes inhibiting prostate cancer cell proliferation, including treating a human patient.

It will be appreciated by one of skill in the medical arts that the exact manner of administering treatment according to the invention will be at the discretion of the attending physician. The mode of administration, including dosage, combination with other anti-cancer agents, timing and frequency of administration, and the like, may be affected by the diagnosis of a patient's likely responsiveness, as well as the patient's condition and history. The effectiveness of treatment of any of the methods of treatment described herein can, be determined, for example, by measuring the decrease in size of tumors present in the patients with the neoplastic condition, or by assaying a molecular determinant of the degree of proliferation of the tumor cells.

In some embodiments, each of the active agents can be administered according to approved labeling existing at the time of treatment. The agents can be typically administered to the patient in a dose regimen that provides for the most effective treatment of the cancer (from both efficacy and safety perspectives) for which the patient is being treated, as known in the art, and as disclosed below.

In some embodiments, the active agents can be co-administered to the patient in the same formulation. In some embodiments, the active agents can be administered to the patient in separate formulations. In some embodiments, the administration of the active agents can be simultaneous. In some embodiments, the administration of the active agents can be sequential.

In some embodiments, the mTOR inhibitor and the ARA can be administered orally.

In one embodiment, active agents can be co-administered to the patient by the same route. In another embodiment, the active agents can be co-administered to the patient by different routes.

The pharmaceutical compositions described above can be used to carry out the treatment methods.

In some embodiments, the mTOR inhibitor is administered according to a regimen that maximizes its effectiveness within a therapeutic window that avoids unacceptable toxicity. OSI- 027 can be administered, for example, once daily (QD), or less than once daily. In some embodiments, OSI-027 can be administered once weekly, or once daily on the first 3-5 days of each week. OSI-027 can be administered in an amount of about 10-250 mg, 20-150 mg, 30- 200 mg, 30-100 mg, or 100-250 mg QD on days of administration. In some embodiments, intermittent dosing is used, for example treating with the mTOR inhibitor on the first five of every seven days or some variation thereof.

In some embodiments, MDV3100 is administered at about 20-500 mg/day or at about

160mg per day, as an oral agent. In some embodiments, A51 or A52 is administered at about 20-500 mg/day or at about

160mg per day, as an oral agent.

In some embodiments, bicalutamide is administered according to approved methods, or about 25 - 150 mg QD; flutamide about 100-500 mg or 250 mg TID; nilutamide about 100-500 mg QD or about 150-300 mg QD.

In some embodiments, the treatment method results in a synergistic decrease in the number of viable tumor cells.

In some aspects, the patient survives for at least about 16, 18, 20, 22, 24, 30, or 36 months. EXPERIMENTAL

Cell Lines: Cell lines were routinely passaged in complete media containing 10% fetal bovine serum (FBS) and all experiments were performed with cells passaged less than 20 times. Prior to preparation of cell lysates, cells were plated in complete growth media and allowed to recover overnight. The following day, cells were washed three times in Hanks balanced salt solution (HBSS, Life technologies) and then cultured in media containing 10% charcoal-stripped serum supplemented with 10nM di-hydroxytestosterone (DHT, Sigma Chemicals), plus vehicle control or drug. Whole-cell lysates were prepared 24 hours after drug treatment. All cell lines were purchased from ATCC or Sigma Chemicals and cultured according to recommended conditions, with the exception of LnCap-AI cells and PC-3 cells. LnCap-AI cells, a variant of LnCap with acquired androgen insensitivity, cells were a gift of Dr. L. Hewitt of University of Newcastle on Tyne and were cultured as LnCap cells. PC-3 cells were licensed from the National Cancer Institute and were cultured in RPMI supplemented with 10% fetal calf serum and 1 % L-Glutamine.

Proliferation assays: To determine the effect of drug or drug combinations on cell proliferation, cells were seeded into 96-well plates and incubated for 4 days in the presence of vehicle control or test drug at varying concentrations. Inhibition of cell growth was determined by luminescent quantification of intracellular ATP content using CellTiterGlo (Promega), according to the protocol provided by the manufacturer. Inhibition of cell growth was also determined by direct quantitation of viable cell number. For this method cells, were stained with Hoechst dye (Sigma chemicals) for 30 minutes to fluorescently label cell nuclei, and cells were imaged and counted using In Cell Analyzer 2000 (GE). Cell nuclei surrounded by intact cells were quantitated for each sample well. A comparison of cell number on day 0 versus 96 hours post drug treatment was used to plot dose-response curves. The number of viable cells was determined and normalized to vehicle-treated controls. Inhibition of proliferation, relative to vehicle-treated controls was expressed as a fraction of 1 and graphed using PRISM^® software (Graphpad Software, San Diego, CA). EC₅₀ values were determined with the same application. Measurement of apoptosis: Induction of apoptosis as measured by increased Caspase

3/7 activity was determined using the Caspase 3/7 Glo assay (Promega Corporation, Madison, Wl). Cell lines were seeded at a density of 3000 cells per well in a 96-well plate. 24 hours after plating cells were dosed with varying concentrations of drug, either as a single agent or in combination. The signal for Caspase 3/7 Glo was determined 48 hours after dosing. Apoptosis was expressed as the fold increase in induction relative to DMSO treated cells. All graphs were generated using PRISM^® software (Graphpad Software, San Diego, CA).

Analysis of Synergy: The Bliss additivism model was used to classify the effect of combination as additive, synergistic or antagonistic. A theoretical curve was calculated for combined inhibition using the equation: E_b|_iss = E_A + E_B - E_A ^*E_B, where E_A and E_B are the fractional inhibitions obtained by drug A alone and drug B alone at specific concentrations. Here, E_bNss is the fractional inhibition that would be expected if the combination of the two drugs was exactly additive. If the experimentally measured fractional inhibition was less than E_b|_iss the combination was said to be synergistic. If the experimentally measured fractional inhibition was greater than E_b|_iss the combination was said to be antagonistic. For dose response curves, the bliss additivity was calculated for varying doses of drug A when combined with a constant dose of drug B. This allowed an assessment as to whether drug B affected the potency of drug A or shifted its intrinsic activity. All plots were generated using Graphpad Prism software.

Cellular protein analysis: Cell extracts were prepared by detergent lysis (50m M Tris- HCI, pH 8.0, 150mM NaCI, 1 % NP-40, 0.5% sodium deoxycholate, 0.1 % SDS, containing protease inhibitor (P8340, Sigma, St. Louis, MO) and phosphatase inhibitor (P5726, Sigma, St. Louis, MO) cocktails. The soluble protein concentration was determined by micro-BSA assay (Pierce, Rockford IL). Protein immunodetection was performed by electrophoretic transfer of SDS-PAGE separated proteins to nitrocellulose, incubation with antibody, and chemiluminescent second step detection. Nitrocellulose membranes were blocked with 5% nonfat dry milk in TBS and incubated overnight with primary antibody in 5% bovine serum albumin. The following primary antibodies from Cell Signaling Technology were used at 1 :1 ,000 dilution, phospho-AKT[S473], phospho-AKT[T308], AKT, phospho-PRAS40 (T246), PRAS40, phospho-S6 [S235/236], S6, Cleaved Parp, Her2 and Her3 Antibodies against Her2 and Her3. Primary antibody against Androgen Receptor (Santa Cruz Biotechnology) was diluted at 1 :500 and 1 :5000 respectively in 5% nonfat dry milk and incubated overnight. β-Actin antibody, used as a control for protein loading, was purchased from Sigma Chemicals. Horseradish peroxidase-conjugated secondary antibodies were obtained from GE Healthcare. Horseradish peroxidase-conjugated secondary antibodies were incubated in nonfat dry milk for 1 hour. SuperSignal chemiluminescent reagent (Pierce Biotechnology) was used according to the manufacturer's directions and blots were imaged using the Alpha Innotech image analyzer and AlphaEaseFC software (Alpha Innotech, San Leandro CA). Results: To model the efficacy of targeted inhibitors in prostate cancer, multiple prostate cancer cell lines including those derived from bone metastasis (Mda-PCa-2b) and those with acquired androgen insensitivity (LnCap-AI) were cultured. In this panel of prostate cancer cell lines, only one of the cell lines tested exhibited significant sensitivity to an androgen antagonist, bicalutamide (Fig. 1A) or an androgen receptor signaling inhibitor, MDV3100 (Fig. 1 B). All cell lines tested were sensitive to the mTORC1/mTORC2 inhibitor OSI-027 (Fig. 1C). EC50 values for inhibition of proliferation by OSI-027 ranged from 0.7 to 3.7 micromolar.

OSI-027 influence on signaling in prostate cancer cells (Fig. 2). When LnCap cells were treated with 10 micromolar OSI-027, decreased phosphor-S6 was observed, consistent with inhibition of mTORCI function. Decreased phosphorylation of Akt and its substrate Pras40 was also observed, consistent with inhibition of mTORC2 activity. Akt signaling is a key survival node for cancer cells and inhibition of Akt can lead to increased cell death, as evidenced by the increase in cleaved Parp, a measure of cellular apoptosis. OSI-027 treatment caused a significant increase in cleaved Parp. The allosteric mTORCI inhibitor, rapamycin inhibited phosphorylation of S6 but not Akt and Pras40, as expected. Rapamycin is an effective inhibitor of mTORCI but has only been shown to inhibit mTORC2 in vitro when given at high concentrations at later time points. To further evaluate the effects of inhibition of the mTOR signaling axis, a selective inhibitor of the PI3 kinase, BKM120, was tested. Inhibition of PI3K resulted in decreased Akt signaling but not S6 phosphorylation. Interestingly, treatment of LnCap cells with OSI-027, rapamycin or BKM120 resulted in a significant increase in expression of the receptor tyrosine kinases Her2 and Her3 as well as expression of androgen receptor, suggesting that treatment of prostate cancer cells with an inhibitor of the mTOR axis may sensitize these cells to the effects of an androgen antagonist or androgen receptor inhibitor. In cells treated with the androgen receptor antagonist, MDV3100, an increase in Akt and Pras40 phosphorylation, and a decrease in AR expression were observed. The observed increase in Akt signaling suggests that MDV3100 treatment may increase reliance on the mTORC2 pathway, sensitizing cells to the effects of inhibitors of this axis, such as OSI-027 or BKM120.

To evaluate the ability of these compounds to cooperate with bicalutamide or MDV3100 to inhibit cell growth and induce cell death, cells were treated with the combination of OSI-027 and bicalutamide, then OSI-027 or BKM120 with MDV3100. Bicalutamide inhibited proliferation of LnCap cells no more than 20% at the highest concentration, however addition of 1 μΜ OSI- 027 resulted in significantly greater maximal inhibition and decreased EC50 (Fig. 3A). The Bliss algorithm was used to predict the dose response curve if the combination of these two drugs were purely additive, and this is shown by the dotted line. The experimental data for the combination of OSI-027 and bicalutamide falls significantly below the prediction for additivity, demonstrating a synergistic interaction. The effect of the drug combination on caspase- dependent cell death was evaluated. Bicalutamide alone did not induce caspase 3/7 activity, however the addition of OSI-027 resulted in synergistic induction of cell death as shown in Fig. 3B. Similarly, OSI-027 sensitized cells to the effects of MDV3100. The combination of the two drugs resulted in more potent and greater maximal inhibition than either monotherapy, as well as greater induction of caspase-dependent cell death than either monotherapy. The differences were found to be statistically significant. The effect of the PI3K inhibitor, BKM120 in combination with MDV3100 provided greater maximal inhibition that was additive (Fig. 3E).

The data demonstrate that prostate cancer cells compensate for inhibition of the androgen receptor signaling pathway by upregulating the mTOR/Akt signaling axis thereby promoting cellular survival. This is evidenced by the increased Akt phosphorylation observed following treatment with MDV3100. Conversely, when the mTOR signaling axis is blocked, using rapamycin, an allosteric inhibitor of mTOR, OSI-027, a selective ATP-competitive inhibitor of mTORC1/mTORC2, or BKM120, a selective inhibitor of PI3K, cells compensate by upregulating receptor tyrosine kinases Her2, Her3 and Androgen receptor (AR). These compensatory mechanisms limit the efficacy of monotherapy, suggesting that maximal benefit would be achieved using a combination strategy. These data further suggest that upregulation of PI3K axis signaling may represent a mechanism by which tumors may acquire resistance to an antagonist of androgen signaling. Co-inhibition of the mTOR axis and AR leads to attenuation of signaling through both pathways. When mTORC2 was inhibited, as demonstrated by decreased phospho-Akt and phosho-Pras40, an increase in cleaved Parp was observed, indicating that inhibition of this cellular survival node drives cell death. Dual inhibition of AR and mTORC2 further enhanced cell death as measured by cleaved Parp. Co-inhibition on cell proliferation and demonstrated that co-inhibition of AR and mTORC1/mTORC2 resulted in an synergistic decrease in the number of viable cells. DEFINITIONS

The language and terms herein are to be given their broadest meaning accepted by the skilled artisan, unless otherwise specified.

The term "cancer" in an animal, including human, refers to the presence of cells possessing characteristics typical of cancer-causing cells, such as uncontrolled proliferation, immortality, metastatic potential, rapid growth and proliferation rate, and certain characteristic morphological features. Often, cancer cells will be in the form of a tumor, but such cells may exist alone within an animal, or may circulate in the blood stream as independent cells, such as leukemic cells.

"Cell growth", as used herein, for example in the context of "tumor cell growth", unless otherwise indicated, is used as commonly used in oncology, where the term is principally associated with growth in cell numbers, which occurs by means of cell reproduction (i.e. proliferation) when the rate of the latter is greater than the rate of cell death (e.g. by apoptosis or necrosis), to produce an increase in the size of a population of cells, although a small component of that growth may in certain circumstances be due also to an increase in cell size or cytoplasmic volume of individual cells. An agent that inhibits cell growth can thus do so by either inhibiting proliferation or stimulating cell death, or both, such that the equilibrium between these two opposing processes is altered.

"Tumor growth" or "tumor metastases growth", as used herein, unless otherwise indicated, is used as commonly used in oncology, where the term is principally associated with an increased mass or volume of the tumor or tumor metastases, primarily as a result of tumor cell growth.

"Abnormal cell growth", as used herein, unless otherwise indicated, refers to cell growth that is independent of normal regulatory mechanisms (e.g., loss of contact inhibition). This includes the abnormal growth of: (1 ) tumor cells (tumors) that proliferate by expressing a mutated tyrosine kinase or over-expression of a receptor tyrosine kinase; (2) benign and malignant cells of other proliferative diseases in which aberrant tyrosine kinase activation occurs; (4) any tumors that proliferate by receptor tyrosine kinases; (5) any tumors that proliferate by aberrant serine/threonine kinase activation; and (6) benign and malignant cells of other proliferative diseases in which aberrant serine/threonine kinase activation occurs.

As used herein, the term "patient" refers to a human in need of treatment with an anticancer agent for any purpose, and more preferably a human in need of such a treatment to treat cancer, or a precancerous condition or lesion.

The term "treating" as used herein, unless otherwise indicated, means reversing, alleviating, inhibiting the progress of, or preventing, either partially or completely, the growth of tumors, tumor metastases, or other cancer-causing or neoplastic cells in a patient. The term "treatment" as used herein, unless otherwise indicated, refers to the act of treating.

The phrase "a method of treating" or its equivalent, when applied to, for example, cancer refers to a procedure or course of action that is designed to reduce or eliminate the number of cancer cells in an animal, or to alleviate the symptoms of a cancer. "A method of treating" cancer or another proliferative disorder does not necessarily mean that the cancer cells or other disorder will, in fact, be eliminated, that the number of cells or disorder will, in fact, be reduced, or that the symptoms of a cancer or other disorder will, in fact, be alleviated. Often, a method of treating cancer will be performed even with a low likelihood of success, but which, given the medical history and estimated survival expectancy of an animal, is nevertheless deemed an overall beneficial course of action.

As used herein, "agent" or "biologically active agent" refers to a biological, pharmaceutical, or chemical compound or other moiety. Non-limiting examples include simple or complex organic or inorganic molecule, a peptide, a protein, an oligonucleotide, an antibody, an antibody derivative, antibody fragment, a vitamin derivative, a carbohydrate, a toxin, or a chemotherapeutic compound. Various compounds can be synthesized, for example, small molecules and oligomers (e.g., oligopeptides and oligonucleotides), and synthetic organic compounds based on various core structures. In addition, various natural sources can provide compounds for screening, such as plant or animal extracts, and the like. A skilled artisan can readily recognize that there is no limit as to the structural nature of the agents of the present invention.

The term "agonist" as used herein refers to a compound having the ability to initiate or enhance a biological function of a target protein, whether by inhibiting the activity or expression of the target protein. Accordingly, the term "agonist" is defined in the context of the biological role of the target polypeptide. While preferred agonists herein specifically interact with (e.g. bind to) the target, compounds that initiate or enhance a biological activity of the target polypeptide by interacting with other members of the signal transduction pathway of which the target polypeptide is a member are also specifically included within this definition.

The terms "antagonist" and "inhibitor" are used interchangeably, and they refer to a compound having the ability to inhibit a biological function of a target protein or signaling pathway, whether by inhibiting the activity or expression of the target protein, ability of a target ligand to bind a target receptor, or ability to convert a target ligand to active form. Accordingly, the terms "antagonist" and "inhibitors" are defined in the context of the biological role of the target protein. While preferred antagonists herein specifically interact with (e.g. bind to) the target, compounds that inhibit a biological activity of the target protein by interacting with other members of the signal transduction pathway of which the target protein is a member are also specifically included within this definition. A preferred biological activity inhibited by an antagonist is associated with the development, growth, or spread of a tumor, or an undesired immune response as manifested in autoimmune disease.

As used herein, the term "mTOR inhibitor that binds to and directly inhibits both mTORCI and mTORC2 complexes" refers to any mTOR inhibitor that binds to and directly inhibits both mTORCI and mTORC2 complexes that is currently known in the art, or will be identified in the future, and includes any chemical entity that, upon administration to a patient, binds to and results in direct inhibition of both mTORCI and mTORC2 complexes in the patient.

The term "allosteric inhibitor of mTOR" refers to rapamycin (sirolimus) and its analogs, everolimus, temsirolimus, deferolimus and ridaforolimus, which allosterically inhibit mTOR through disruption of the mTORCI complex.

The term "PI3K" inhibitor" refers to any agent which binds to and inhibits the PI3 Kinase. An "anti-cancer agent", "anti-tumor agent", or "chemotherapeutic agent" refers to any agent useful in the treatment of a neoplastic condition. One class of anti-cancer agents comprises chemotherapeutic agents. "Chemotherapy" means the administration of one or more chemotherapeutic drugs and/or other agents to a cancer patient by various methods, including intravenous, oral, intramuscular, intraperitoneal, intravesical, subcutaneous, transdermal, buccal, or inhalation or in the form of a suppository.

The term "effective amount" or "therapeutically effective amount" refers to that amount of a compound described herein that is sufficient to effect the intended application including but not limited to disease treatment, as defined below. The therapeutically effective amount may vary depending upon the intended application (in vitro or in vivo), or the subject and disease condition being treated, e.g., the weight and age of the subject, the severity of the disease condition, the manner of administration and the like, which can readily be determined by one of ordinary skill in the art. The term also applies to a dose that will induce a particular response in target cells, e.g. reduction of platelet adhesion and/or cell migration. The specific dose will vary depending on the particular compounds chosen, the dosing regimen to be followed, whether it is administered in combination with other compounds, timing of administration, the tissue to which it is administered, and the physical delivery system in which it is carried.

The term "selective inhibition" or "selectively inhibit" as applied to a biologically active agent refers to the agent's ability to selectively reduce the target signaling activity as compared to off-target signaling activity, via direct or interact interaction with the target.

For purposes of the present invention, "co-administration of" and "co-administering" an refer to any administration of the two active agents, either separately or together, where the two active agents are administered as part of an appropriate dose regimen designed to obtain the benefit of the combination therapy. Thus, the two active agents can be administered either as part of the same pharmaceutical composition or in separate pharmaceutical compositions. The OSI-906 can be administered prior to, at the same time as, or subsequent to administration of the OSI-027, or in some combination thereof.

The terms "responsive" or "responsiveness" when used herein in referring to a patient's reaction to administration of an active agent, refers to a response that is positive or effective, from which the patient is likely to benefit.

The term "method for manufacturing a medicament" or "use of for manufacturing a medicament" relates to the manufacturing of a medicament for use in the indication as specified herein, and in particular for use in tumors, tumor metastases, or cancer in general. The term relates to the so-called "Swiss-type" claim format in the indication specified.

In the context of this invention, the sensitivity of tumor cell growth to the OSI-027 is defined as high ("sensitive") if the tumor cell is inhibited with an EC₅₀ (half-maximal effective concentration) of less than 1 μΜ, and low (i.e. resistant) if the tumor cell is inhibited with an EC₅₀ of greater than 10 μΜ. Sensitivities between these values are considered intermediate.

In the context of this invention, the sensitivity of tumor cell growth to an ARA is defined as high ("sensitive") if the tumor cell is inhibited with an EC₅₀ (half-maximal effective concentration) of less than 1 μΜ, and low (i.e. resistant) if the tumor cell is inhibited with an EC₅₀ of greater than 3 μΜ. Sensitivities between these values are considered intermediate.

The term EC₅₀ (half maximal effective concentration) refers to the concentration of agent that induces a response halfway between the baseline and maximum for the specified exposure time, and is used as a measure of the compound's potency.

Claims

1. A method of treating prostate cancer in a human patient in need thereof, comprising administering an effective regimen comprising OSI-027 and an androgen receptor antagonist.

2. The method of Claim 1 , wherein the prostate cancer is metastatic castrate-resistant prostate cancer.

3. The method of Claim 1 , wherein the prostate cancer is asymptomatic castrate- resistant prostate cancer.

4. The method of any one of Claims 1-3, wherein the androgen antagonist is a nonsteroidal agent.

5. The method of any one of Claims 1-3, wherein the androgen antagonist is selected from bicalutamide, flutamide, nilutamide, or abiraterone.

6. The method of any one of Claims 1-3, wherein the androgen antagonist is MDV3100.

7. The method of any one of Claims 1-3, wherein the androgen antagonist is A51 or

A52.

8. The method of Claim 6, wherein the MDV3100 is administered in an amount of about 160 mg/day.

9. The method of Claim 6, wherein the cancer is resistant to single agent bicalutamide, flutamide, or nilutamide.

10. The method of Claim 6, wherein the cancer is resistant to MDV3100 when administered as a single agent.

1 1 . The method of Claim 7, wherein the cancer is resistant to A51 or A52 when administered as a single agent.

12. The method of any one of Claims 1-1 1 , wherein the cancer is resistant to OSI-027 when administered as a single agent.

13. The method of any one of Claims 1-12, wherein the OSI-027 is administered in an amount of about 30-200 mg QD on days of administration.

14. The method of any one of Claims 1-13, wherein the patient survives for at least about 20 months.

15. A method of treating a human patient having a tumor or tumor metastasis that has acquired resistance to androgen receptor antagonist therapy, comprising administering an effective regimen comprising OSI-027 and an androgen receptor antagonist.

16. The method of Claim 15, wherein the cancer is breast or endometrial cancer.

17. A method of synergistically inhibiting castration resistant prostate cancer cell proliferation comprising treating castration resistant prostate cancer cells with OSI-027 and an androgen antagonist.

18. The method of Claim 17, wherein the androgen antagonist is MDV3100.

19. The method of Claim 17, wherein the androgen antagonist is A51 or A52.

20. The use of OSI-027 in the manufacture of a medicament for treating prostate cancer in combination with an androgen antagonist.

21 . The use of Claim 20, wherein the androgen antagonist is MDV3100.

22. The use of Claim 20, wherein the androgen antagonist is A51 or A52.

23. A pharmaceutical composition comprising OSI-027 and MDV3100 and at least one pharmaceutically acceptable carrier.

24. A pharmaceutical composition comprising OSI-027 and A51 or A52 and at least one pharmaceutically acceptable carrier.

25. A kit comprising at least one container, compositions comprising OSI-027 and MDV3100, A51 , or A52, and a package insert comprising instructions for use to treat prostate cancer.