Xtandi enzalutamide regulatory update

Astellas said the Japanese label for Xtandi enzalutamide was updated to remove a line stating that the efficacy and safety of the drug has not been established in patients with prostate cancer who have not received chemotherapy. The label revision triggered a $45 million payment to Medivation from Astellas under the companies' 2009 deal to develop and commercialize the oral androgen receptor antagonist (see BioCentury, Nov. 2, 2009). In March, Japan approved the product for castration-resistant prostate cancer (CRPC) but with the precaution against the use in chemotherapy-naive patients.

The label change was based on the results of the double-blind, international Phase III PREVAIL trial. In October 2013, PREVAIL was stopped early on the recommendation of an IDMC after an interim analysis showed that Xtandi plus standard of care (SOC) met the co-primary endpoints of improving median overall survival (OS) and median radiographic progression-free survival (PFS) vs. placebo plus SOC in chemotherapy-naive patients with metastatic CRPC who failed androgen deprivation therapy (see BioCentury, Oct. 28, 2013). The partners reported final data from the trial in January (see BioCentury, Feb. 3). ...