FDA Approves Enzalutamide for Metastatic Castration-Sensitive Prostate Cancer
Posted: Wednesday, December 18, 2019
On December 16, 2019, Pfizer and Astellas Pharma announced that the U.S. Food and Drug Administration (FDA) approved a supplemental new drug application for enzalutamide (Xtandi) for the treatment of patients with metastatic castration-sensitive prostate cancer. With this approval, enzalutamide has now been approved in the treatment of three types of advanced prostate cancer: nonmetastatic and metastatic castration-resistant prostate cancer, and metastatic castration-sensitive prostate cancer.
The approval is based on results from the randomized phase III ARCHES trial, which evaluated 1,150 men with metastatic castration-sensitive prostate cancer and met its primary endpoint of radiographic progression-free survival. Data from the ARCHES trial demonstrated that the use of enzalutamide plus androgen-deprivation therapy significantly reduced the risk of radiographic disease progression or death by 61% compared with placebo plus androgen-deprivation therapy (n = 1,150; hazard ratio = 0.39 [95% confidence interval = 0.30–0.50]; P < .0001). Overall survival data were not mature at the time of final analysis of radiographic progression-free survival.
The safety analysis of the ARCHES trial is generally consistent with the safety profile of enzalutamide in previous clinical trials in castration-resistant prostate cancer. In the ARCHES trial, common adverse reactions that were reported more frequently in patients treated with enzalutamide plus androgen-deprivation therapy vs placebo plus androgen-deprivation therapy included hot flush (27% vs. 22%), asthenic conditions (24% vs. 20%), hypertension (8.0% vs. 5.6%), fractures (6.5% vs. 4.2%), and musculoskeletal pain (6.3% vs. 4.0%).