The Food and Drug Administration (FDA) has approved a supplemental New Drug Application (sNDA) for Xtandi (enzalutamide; Astellas Pharma) for the treatment of patients with metastatic castration-sensitive prostate cancer (mCSPC). Previously, Xtandi was only approved for both non-metastatic and metastatic castration-resistant prostate cancer.
The sNDA approval was based on data from the phase 3, double-blind, placebo-controlled ARCHES trial that evaluated the efficacy and safety of Xtandi plus androgen deprivation therapy (ADT) in 1150 patients with mCSPC. Patients were randomized 1:1 to receive either Xtandi 160mg once daily plus ADT (n=574) or placebo plus ADT (n=576). The primary end point was radiographic progression-free survival (rPFS), defined as the time from randomization to radiographic disease progression at any time or death within 24 weeks after drug discontinuation.
Results demonstrated that Xtandi plus ADT significantly reduced the risk of radiographic progression or death by 61% compared with placebo plus ADT (hazard ratio [HR] 0.39; 95% CI: 0.30, 0.50; P <.0001). Xtandi plus ADT also reported a statistically significant improvement in the time to initiation of a new antineoplastic therapy (secondary end point) as compared with placebo (HR 0.28; 95% CI: 0.20, 0.40; P <0.0001). Overall survival (OS) data were not mature at the time of rPFS analysis.
With regard to safety, the most common adverse reactions in the Xtandi treatment arm were hot flush, asthenia/fatigue, hypertension, fractures, and musculoskeletal pain.
“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, Professor of Medicine, Surgery, Pharmacology and Cancer Biology, Director of Research in 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.”
Xtandi, an androgen receptor inhibitor, is supplied as 40mg capsules in 120-count bottles.
For more information visit Xtandi.com.