Enzalutamide: A Review of Its Use in Metastatic, Castration-Resistant Prostate Cancer

Enzalutamide (MDV3100, XTANDI (R)) is an androgen receptor inhibitor that is indicated for the treatment of metastatic, castration-resistant, prostate cancer (mCRPC) that has progressed despite treatment with docetaxel. This article reviews the pharmacology, efficacy and tolerability of enzalutamide relevant to this indication. In a randomized, double-blind, placebo-controlled, multinational, phase III trial in patients with mCRPC progressing after docetaxel therapy, enzalutamide significantly prolonged overall survival (OS), delayed prostate specific antigen progression and prolonged radiographic progression-free survival and time to the first skeletal event. The median OS was 18.4 months in the enzalutamide group and 13.6 months in the placebo group, which represents a 37 % reduction in the mortality risk in the enzalutamide group. Enzalutamide was also associated with significant benefits in health-related quality of life and in pain palliation. Enzalutamide was generally as well tolerated as placebo during the trial, with most adverse events at a mild or moderate level of severity. Enzalutamide carries a small increased risk of seizures that appears to be dose-dependent. Enzalutamide is an efficacious and well tolerated treatment for this severe, rapidly progressive disease.