Dr. Karsh on the TERRAIN Trial for Prostate Cancer

Lawrence Karsh, MD, FACS, director, Clinical Research Department, The Urology Center of Colorado, discusses the TERRAIN trial, which compared enzalutamide with bicalutamide for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC).

The randomized TERRAIN trial, which enrolled 375 patients, compared the efficacy of the two single-agents, Karsh explains. In preclinical studies, enzalutamide demonstrated efficacy because it was tested against bicalutamide-resistant cells, he adds. The primary endpoint of the TERRAIN trial was progression-free survival (PFS), with secondary endpoints being change in prostate-specific antigen (PSA) and quality of life indicators.

PFS was 15.7 months in the enzalutamide arm versus 5.8 months in the bicalutamide arm. A higher PSA response was also found in the enzalutamide cohort compared with the bicalutamide cohort. Patients had longer time to deterioration when treated with enzalutamide compared with bicalutamide by approximately 5 months. In summary, Karsh says, enzalutamide has a higher efficacy rate than bicalutamide.