LONDON, STAINES, England and SAN FRANCISCO, March 30, 2011 /PRNewswire/ -- Astellas Pharma Europe Ltd. and Medivation, Inc. today announced treatment of the first patient in the TERRAIN trial, a Phase 2 comparison of the investigational drug MDV3100, a triple-acting, oral androgen receptor antagonist, with bicalutamide, a commonly used non-steroidal anti-androgen, for the treatment of advanced prostate cancer in patients who have progressed while on LHRH analogue therapy or following surgical castration.

"Given the novel mechanism of MDV3100, this study has the potential to answer fundamental clinical questions about continued androgen receptor signalling in patients with progressive prostate cancer despite castrate levels of testosterone," said Professor Axel Heidenreich, Principal Investigator of the TERRAIN trial, from Universitätsklinikum der RWTH in Aachen, Germany, "We look forward to the results of this important trial."

The TERRAIN Phase 2 trial is expected to enroll approximately 370 patients in Europe and North America. The primary endpoint of the trial is progression-free survival.

"MDV3100 has been shown in preclinical studies to provide more complete suppression of the androgen receptor signalling pathway than existing anti-androgens and the TERRAIN study provides the opportunity to investigate this finding further in a clinical setting," said Lynn Seely, M.D., Chief Medical Officer of Medivation. "MDV3100 is currently in Phase 3 testing for advanced prostate cancer, but our goal is to determine if MDV3100 can benefit men with prostate cancer earlier in the course of the disease."

"This is the first of two Phase 2 trials in earlier-stage disease that we and our partner Medivation will initiate this year to evaluate the potential benefit of MDV3100 in a broad spectrum of prostate cancer patients," said Steven Ryder, M.D., President, Astellas Pharma Global Development. "The second of our new Phase 2 trials will study MDV3100 in an even earlier-stage population - hormone naïve prostate cancer patients who are indicated for androgen deprivation therapy. We expect to begin that trial in the first half of this year."

MDV3100 Phase 3 Clinical Development Programme

In addition to the TERRAIN trial, MDV3100 is currently being evaluated in two global Phase 3 studies in patients with advanced prostate cancer.

The randomised, double-blind, placebo-controlled Phase 3 AFFIRM trial completed enrollment in November 2010. This trial of 1,199 patients with advanced prostate cancer who were previously treated with docetaxel-based chemotherapy is evaluating 160 mg/day of MDV3100 versus placebo. The primary endpoint is overall survival.

A second Phase 3 clinical trial of MDV3100 in advanced prostate cancer, the PREVAIL trial, is currently enrolling patients. This randomised, double-blind, placebo-controlled, multi-national trial of approximately 1,700 men with advanced prostate cancer who have not yet received chemotherapy is evaluating MDV3100 at a dose of 160 mg taken orally once daily plus standard of care versus placebo plus standard of care. The co-primary endpoints of the trial are overall survival and progression-free survival.