Pfizer's XTANDI Reduced Metastasis Risk by 58% in Prostate Cancer Trial

Pfizer and Astellas Pharma announced that XTANDI (enzalutamide) combined with leuprolide significantly reduced the risk of metastasis or death by 58% versus placebo plus leuprolide. These findings are from the Phase 3 EMBARK trial, focused on men with high-risk biochemical recurrence of non-metastatic hormone-sensitive prostate cancer.

The primary endpoint of metastasis-free survival (MFS) in the EMBARK study demonstrated a statistically significant benefit for the XTANDI combination therapy. The trial evaluated three arms: XTANDI plus leuprolide, placebo plus leuprolide, and XTANDI monotherapy.

Data also revealed that XTANDI monotherapy alone reduced the risk of metastasis or death by 37% compared to leuprolide plus placebo. Both XTANDI treatment groups showed substantial reductions in the risk of PSA progression.

A positive trend in overall survival was observed in the XTANDI combination arm, though further data is needed for a final analysis. The companies plan to discuss these results with regulatory authorities, including the U.S. Food and Drug Administration (FDA), to support a potential submission for XTANDI in this indication later in 2023.

The EMBARK trial is a multinational, randomized, double-blind, placebo-controlled Phase 3 study that enrolled 1,068 patients with high-risk biochemical recurrence.