The FDA has approved a supplemental New Drug Application (sNDA) for enzalutamide (XTANDI) for the treatment of patients with metastatic castration-sensitive prostate cancer (mCSPC).
With the approval, enzalutamide becomes the first and only oral treatment approved by the FDA for three types of advanced prostate cancer: non-metastatic and metastatic castration-resistant prostate cancer (CRPC) and mCSPC, according to a statement from Pfizer and Astellas. The approval is based on results from ARCHES, a randomized phase 3 study of 1,150 men with mCSPC that met its primary endpoint of radiographic progression-free survival (rPFS).
Data from the ARCHES trial demonstrated that the use of enzalutamide plus androgen deprivation therapy (ADT) significantly reduced the risk of radiographic progression or death by 61% compared to placebo plus ADT (n=1,150; hazard ratio [HR]: 0.39 [95% CI: 0.30-0.50]; p<.0001). Overall survival data were not mature at the time of final rPFS analysis.
The safety analysis of the ARCHES trial is generally consistent with the safety profile of enzalutamide in previous clinical trials in CRPC, Pfizer and Astellas said. In ARCHES, common adverse reactions (grade 1 to 4 ARs; occurring in at least 5% of patients) that were reported more frequently in patients treated with enzalutamide plus ADT versus placebo plus ADT 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%).
“Men with metastatic castration-sensitive prostate cancer face complex treatment decisions and it is critical for physicians and patients to have as much information as possible when deciding on all of the options available,” said Andrew Armstrong, MD, of the Duke Cancer Institute’s Center for Prostate and Urologic Cancers and lead investigator of ARCHES. “The research supporting the FDA approval and updated treatment guidelines provide physicians and patients with compelling evidence to consider enzalutamide as a treatment option for men with this disease.”