Dr. Mohler Discusses Prostate Cancer Trial Endpoints

James Mohler, MD, Associate Director and Senior-Vice President for Translational Research, Chair, Department of Urology, Professor of Oncology, Roswell Park Cancer Institute, discusses the need to develop intermediate endpoints for clinical trials investigating treatments for prostate cancer in order to facilitate the early-stage adoption of new antiandrogen agents, such as abiraterone acetate (Zytiga) and enzalutamide (MDV3100).

Mohler states that the prime reason that newer agents for prostate cancer are being studied for castration-resistant prostate cancer (CRPC) and not earlier stages is because CRPC offers a shorter endpoint, since survival is 18 months on average.

As these drugs are studied earlier in the treatment process it will become increasingly difficult to use survival as an endpoint, Mohler states. In general, men with earlier stages of prostate cancer can live a long time, since the disease is generally slow growing. It is also likely that as the patient progresses they will receive multiple interventions, making it practically impossible to use survival as an endpoint.

Mohler believes that a careful discussion with the FDA on intermediate endpoints needs to take place, so that newer agents can be investigated earlier in the disease.