SAN FRANCISCO, CA and TOKYO--(Marketwire - August 04, 2011) - Medivation, Inc. (NASDAQ: MDVN) and Astellas Pharma Inc. today announced results from a preclinical study conducted by researchers at the University of Colorado Denver that provide evidence that MDV3100 inhibits proliferation of breast cancer cells. In different cell-based assays, MDV3100 was able to inhibit both androgen- and estrogen-mediated breast cancer cell proliferation. MDV3100 is a triple-acting, oral androgen receptor antagonist in clinical development to treat a broad spectrum of advanced prostate cancer patients.
"Our findings are exciting because they challenge the existing idea that androgens are protective in breast cancer by demonstrating that androgens can stimulate proliferation of breast cancer," said Jennifer K. Richer, Ph.D., lead study investigator and associate professor in the Department of Pathology at the University of Colorado Anschutz Medical Campus. "These preclinical data show that MDV3100 suppresses androgen-driven breast cancer cell growth and, surprisingly, also suppresses estrogen-driven breast cancer cell growth."
"The vast majority of breast cancers express estrogen receptors, androgen receptors or both," said Lynn Seely, M.D., chief medical officer of Medivation. "The proven activity of MDV3100 against the androgen receptor and these intriguing new preclinical data suggesting potential activity against estrogen-mediated pathways suggest that MDV3100 may have therapeutic utility in breast cancer, something that would of course need to be investigated through clinical trials."
Study Design and Results
Using ER+/AR+ breast cancer cells, the researchers investigated whether blocking androgen receptor activity could serve as a therapeutic strategy for such tumors. ER+/AR+ breast cancer cells were treated with the androgens dihydrotestosterone (DHT) or R1881, a potent testosterone analog, or estradiol (E2). The preclinical study sought to determine if MDV3100 could block androgen- or estrogen-mediated proliferation.
Results showed that DHT treatment had a proliferative effect on breast cancer cells which was blocked by MDV3100. However, MDV3100 also blocked estrogen-mediated proliferation of breast cancer cells. Preclinical experiments in the Richer laboratory confirmed that MDV3100 decreases in vivo tumor growth driven by DHT or estradiol.
The data were presented by Dr. Richer at the Department of Defense Breast Cancer Research Program's 2011 Era of Hope Conference in Orlando, FL.
MDV3100 is an investigational therapy in clinical development for advanced prostate cancer. In a Phase 1-2 trial in 140 patients with advanced prostate cancer published in The Lancet, encouraging antitumor activity was noted with MDV3100 across endpoints. In preclinical experiments published in Science in April 2009, the triple-acting, oral androgen receptor antagonist provided more compIete suppression of the androgen receptor pathway than bicalutamide. MDV3100 slowed growth and induced cell death in bicalutamide-resistant cancers via three complementary actions -- MDV3100 blocked testosterone binding to the androgen receptor, impeded movement of the androgen receptor to the nucleus of prostate cancer cells (nuclear translocation) and inhibited binding to DNA. In the preclinical experiments published in Science, MDV3100 was superior to bicalutamide in each of these three actions.
About the Medivation/Astellas Collaboration
In October 2009, Medivation and Astellas entered into a global agreement to jointly develop and commercialize MDV3100. The companies are collaborating on a comprehensive development program that includes studies to develop MDV3100 across the full spectrum of advanced prostate cancer disease states. Subject to receipt of regulatory approval, the companies will jointly commercialize MDV3100 in the U.S. and Astellas will have responsibility for commercializing MDV3100 outside the U.S. Medivation received a $110 million up-front payment upon entering into the collaboration agreement, and is eligible to receive up to $335 million in development milestone payments, up to $320 million in commercial milestone payments, 50 percent of profits on sales in the U.S., and tiered, double-digit royalties on sales outside the United States.
Medivation, Inc. is a biopharmaceutical company focused on the rapid development of novel small molecule drugs to treat serious diseases for which there are limited treatment options. Medivation aims to transform the treatment of these diseases and offer hope to critically ill patients and their caregivers. Together with its corporate partners Astellas and Pfizer, Medivation currently has investigational drugs in Phase 3 development to treat advanced prostate cancer and mild-to-moderate Alzheimer's disease. For more information, please visit us at www.medivation.com.
About Astellas Pharma Inc.
Astellas Pharma Inc., located in Tokyo, Japan, is a pharmaceutical company dedicated to improving the health of people around the world through provision of innovative and reliable pharmaceuticals. Astellas has approximately 16,000 employees worldwide. The organization is committed to becoming a global category leader in Urology, Immunology & Infectious Diseases, Oncology, Neuroscience, and DM complications & Metabolic Diseases. For more information on Astellas Pharma Inc., please visit our website at www.astellas.com/en.
MEDIVATION DISCLOSURE NOTICE: This press release contains forward-looking statements, including statements regarding the continued clinical development of Medivation's product candidates, the therapeutic potential of MDV3100, potential regulatory approval and commercialization of MDV3100, and the continued effectiveness of, and continuing collaborative activities under, Medivation's collaboration agreements with Pfizer and Astellas, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Forward-looking statements involve risks and uncertainties that could cause Medivation's actual results to differ significantly from those projected, including, without limitation, risks related to progress, timing and results of Medivation's clinical trials, including the risk that adverse clinical trial results could alone or together with other factors result in the delay or discontinuation of some or all of Medivation's product development activities, the risk that positive results from preclinical studies and early clinical trials may not be predictive of results obtained in later and larger clinical trials, and the risk that alternative life-prolonging treatments could prevent ongoing or planned MDV3100 trials from succeeding or could reduce any potential survival benefit that may be shown in these trials even if they do succeed, enrollment of patients in Medivation's clinical trials, partnering of Medivation's product candidates, including Medivation's dependence on the efforts of and funding by Astellas for the development of MDV3100, the achievement of development, regulatory and commercial milestones under Medivation's collaboration agreement with Astellas, the manufacturing of Medivation's product candidates, the adequacy of Medivation's financial resources, unanticipated expenditures or liabilities, intellectual property matters, and other risks detailed in Medivation's filings with the Securities and Exchange Commission, including its quarterly report on Form 10-Q for the quarter ended March 31, 2011, filed on May 6, 2011 with the SEC. You are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this release. Medivation disclaims any obligation or undertaking to update or revise any forward-looking statements contained in this press release.