Single-center phase 2 trial of masofaniten plus enzalutamide for treatment-naïve metastatic hormone-sensitive prostate cancer

Anitens are a family of oral N-terminal domain inhibitors of the androgen receptor. Masofaniten (EPI-7386) is a next-generation aniten with promising activity in patients with metastatic castrate-resistant prostate cancer. The phase 2 EXTRA-PC trial at Case Western Reserve University School of Medicine (Cleveland, OH) evaluated the combination of masofaniten and enzalutamide plus androgen deprivation therapy in patients with treatment-naïve metastatic hormone-sensitive prostate cancer. Among 13 patients (5 AA, 8 NHW; median age 68 years, range 52-65), median duration of follow-up was 9.9 months (range 7.7-15.6). Ten of 13 patients (77%; 95% CI 50-92) achieved a PSA < 0.2 ng/mL at 6 months. Only one patient had disease progression to metastatic castrate-resistant disease. The authors conclude that the combination of masofaniten and enzalutamide for treatment-naïve metastatic hormone-sensitive prostate cancer did show efficacy and had an acceptable safety profile.