A study arm from the phase 3 EMBARK trial evaluating XTANDI (enzalutamide) for the treatment of non-metastatic castration-sensitive prostate cancer (nmCSPC) with high-risk biochemical recurrence (BCR) has resulted in positive patient outcomes, according to Pfizer and Astellas Pharma.
The phase 3, randomized, double-blind, placebo-controlled, multinational EMBARK trial utilized 3 different study arms: enzalutamide plus leuprolide, placebo plus leuprolide, and enzalutamide monotherapy. A total of 1068 patients with nmCSPC who were considered to have high-risk BCR were enrolled and randomized to receive either enzalutamide 160 mg daily plus leuprolide, enzalutamide 160 mg as a monotherapy, or placebo plus leuprolide.
The trial’s primary end point was metastasis-free survival (MFS) for enzalutamide plus leuprolide and placebo plus leuprolide. The study arm investigating enzalutamide plus leuprolide has met its primary end point, with a significant improvement in MFS for patients compared with placebo plus leuprolide.
The study met several key secondary end points, including time to prostate-specific antigen progression and time to first use of new antineoplastic therapy. A positive trend in overall survival (OS) was also noted, yet data were not yet mature. Study patients will be continuously monitored for a final OS analysis as well as other secondary end points. No new safety profiles have been observed to date, which is consistent with the established safety profile of enzalutamide.
“The topline findings from EMBARK are highly encouraging, and we look forward to engaging with health authorities to potentially bring XTANDI to men with non-metastatic hormone-sensitive prostate cancer with high-risk biochemical recurrence,” said Pfizer’s Chief Development Officer of Oncology and Rare Disease, Chris Boshoff, MD, PhD.
Further data from the EMBARK trial will be discussed with authorities such as the US Food and Drug Administration to support a possible regulatory submission.