The China National Medical Products Administration (NMPA) has approved a new drug application (NDA) for Japan-based Astellas Pharma Inc's (TSE: 4503) XTANDI (enzalutamide) on 18 November, intended for the treatment of adult men with metastatic castration-resistant prostate cancer (CRPC) who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy (ADT) in whom chemotherapy is not yet clinically indicated, it was reported yesterday.

The approval was based on the results of an Asian multinational Phase three, randomised, double-blind, placebo controlled efficacy and safety study of enzalutamide in asymptomatic or mildly symptomatic patients with progressive metastatic prostate cancer who had disease progression despite ADT and a single-dose pharmacokinetic study in healthy Chinese volunteers (Protocol 9785-CL-0013).

The study is called Asian PREVAIL and assessed oral enzalutamide (160mg/day) compared to placebo plus gonadotropin-releasing hormone therapy or after bilateral orchiectomy. The study, involving Asian patients including around 200 Chinese patients, indicated consistent results with those in the global pivotal Phase three PREVAIL study in the same target population.