Medivation, Astellas Begin Breast Cancer Trial

Medivation and Astellas Pharma US have begun a Phase II trial evaluating the safety and efficacy of enzalutamide in combination with exemestane in women with advanced breast cancer that is estrogen receptor positive (ER+) or progesterone receptor positive (PgR+) and human epidermal growth factor receptor 2 (HER2) normal.

The Phase II study is a randomized, double-blind, placebo-controlled, multicenter trial of enzalutamide in combination with exemestane versus placebo plus exemestane in 240 postmenopausal women with advanced breast cancer that is ER+ or PgR+ and HER2 normal that have received no more than one prior chemotherapy and one prior hormonal treatment for their advanced disease. The 240 patients will be assessed in two parallel cohorts of 120 patients each. The first cohort will enroll patients who have not previously received hormonal treatment for advanced breast cancer. The second cohort will enroll patients who have previously progressed following one hormonal treatment for advanced disease. The primary endpoint of the trial is progression-free survival in all patients and in the subset of patients whose tumor expresses the androgen receptor.