Evaluating Significance of ENZAMET Trial in Metastatic Hormone-Sensitive Prostate Cancer

William K. Oh, MD, chief, Division of Hematology and Medical Oncology, and professor of medicine and urology, Mount Sinai Hospital, discusses the rationale for presenting the data for the phase III ENZAMET trial in a plenary session at the 2019 ASCO Annual Meeting. He says these data were significant because it was a large randomized clinical trial for the treatment of newly diagnosed patients with metastatic hormone-sensitive prostate cancer (mHSPC).

Patients with mHSPC were randomized to receive testosterone suppression plus either enzalutamide (Xtandi) or a standard anti-androgen therapy. There was a significant survival benefit in favor of the enzalutamide arm, Oh says, but this was not surprising based on data from STAMPEDE and LATITUDE, which both compared similar agents.

What was unique about the ENZAMET trial was that 45% of patients were allowed to receive chemotherapy, per the physician’s choice. There was no prespecified randomization, which helped to answer the remaining question from prior trials of whether chemotherapy or androgen receptor—targeted therapy is better in this setting. Although these data do not definitively answer this question, the trial did show all benefit from enzalutamide was seen in patients that did not also receive chemotherapy. Oh concludes that there may have been cross activity between 6 cycles of docetaxel chemotherapy and the benefit of enzalutamide.