Medivation and Astellas Pharma have been given an action date by regulators in the USA for their eagerly-anticipated prostate cancer drug enzalutamide.

The US Food and Drug Administration has assigned a Prescription Drug User Fee Act action date of November 22 for enzalutamide (formerly MDV3100) as a therapy for men with castration-resistant prostate cancer previously treated with docetaxel-based chemotherapy. Last month, the agency granted a priority review for the androgen receptor signalling inhibitor.

Enzalutamide, which was filed in Europe in June, excited analysts following the publication of data from the Phase III AFFIRM study, which confirmed that the drug demonstrated a statistically significant improvement in overall survival with a median improvement over placebo of 4.8 months. If approved, it would compete with Johnson & Johnson’s Zytiga (abiraterone).

The companies linked up in October 2009 and the deal could be worth up to $765 million to Medivation. The latter has repeatedly been mentioned as a potential acquisition target of late, given that many observers believe enzalutamide is destined for blockbuster status.