San Francisco-based Medivation Inc. and Astellas Pharma Inc. had plenty to celebrate heading into the Labor Day holiday weekend. The FDA on Friday approved Xtandi (enzalutamide) capsules for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have previously received docetaxel three months ahead of the product's prescription drug user fee goal date of Nov. 22.