Dr. Graff on the KEYNOTE-199 Trial Design in Castration-Resistant Prostate Cancer

Julie N. Graff, MD, associate professor of medicine, Oregon Health & Science University Knight Cancer Institute, discusses the multi-cohort, phase II KEYNOTE-199 study examining patients with metastatic castration-resistant prostate cancer (mCRPC).

The current standard of care for patients with mCRPC varies from place to place, explains Graff. Typically, chemotherapy is available to patients and some providers would consider giving abiraterone acetate (Zytiga) after enzalutamide (Xtandi). This regimen provides some responses in the later-line setting, though not as many when it is given upfront, according to Graff.

Cohorts 1, 2, and 3 in the KEYNOTE-199 involved men with CRPC who received single-agent pembrolizumab (Keytruda) after chemotherapy and next-generation androgen receptor inhibitors. Cohorts 4 and 5 were men with mCRPC prior to chemotherapy who had progressed on enzalutamide after showing a response. Cohort 4 contained patients with measurable disease while cohort 5 comprised patients without measurable disease. Patients continued on enzalutamide and received pembrolizumab every 3 weeks until intolerance or progression, concludes Graff.