A Conversation with Fred Saad, MD, FRCSC
Fred Saad, MD, FRCSC, is professor and chief of urology and director of G-U oncology at the University of Montreal Hospital Centers. He holds the University of Montreal Endowed Chair in Prostate Cancer Research and is director of the molecular oncology research lab in Prostate Cancer at the Montreal Cancer Institute.
He is chair of the National Cancer Institute of Canada G-U Group and the Canadian Urologic Oncology Group. He sits on nine editorial boards and serves as a reviewer for more than 30 urology and oncology journals. He has published more than 200 articles, 700 scientific abstracts, six books, and more than 20 book chapters. His main research interests include molecular prognostic markers in prostate cancer and new therapeutic approaches to metastatic prostate cancer. He coordinates more than 30 clinical and basic research projects in urologic oncology.
He was a presenter at the 15th Annual Meeting of the Society of Urologic Oncology in Bethesda, Maryland, in December 2014.
What are some of the highlights from the data on COU-AA-302 you presented at the SUO meeting?
I presented the final analysis of Cougar 302 [COU-AA-302], which was the randomized study of abiraterone acetate plus prednisone versus placebo plus prednisone in chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC). Median follow-up was 49 months. This analysis confirms an improvement in overall survival as well as excellent long-term safety.
Did the final analysis results reach statistic significance?
Yes. There was a 4.4-month improvement in survival, which is now clearly a statistically significant improvement in overall survival. This is impressive given the number of effective available agents that were available to patients after they left the study. This is especially true of patients who were in the placebo arm. In fact 44% of the placebo patients actually received abiraterone acetate.
What about secondary end points?
All the secondary end points reached statistically significant improvements, including time to chemotherapy, maintenance of ECOG status, prostate-specific antigen (PSA) response as well as time to PSA progression. and improvements in measurable tumor response. This final analysis importantly allowed the abiraterone acetate plus prednisone arm to reach time to pain requiring opiate end point, which confirms a 10-month delay compared with the placebo plus prednisone arm.
Was this the first phase 3 study to evaluate abiraterone acetate plus prednisone in chemotherapy naïve patients?
Yes. [There was a phase 2 study in chemotherapy-naïve patients published previously; however, this was the first phase 3 study to investigate the use of abiraterone acetate plus prednisone in that patient population.]
What are the primary benefits of AA + prednisone for patients with metastatic CRPC?
This study confirms that patients with mCRPC can be safely treated long term with abiraterone acetate plus prednisone and can hope to see a delay in progression of their disease, improvements in survival as well as maintenance of quality of life, and delaying the appearance of pain and the need for chemotherapy. Of interest is the subgroup analysis that suggests that patients with less symptoms, lower PSA and alkaline phosphatase levels appear to have even more survival benefit.
Are there implications for clinical practice?
This is a therapeutic option for the majority of patients with mCRPC and should be part of the therapeutic options that urologic oncologists can offer their patients.
What is the primary takeaway from your presentation?
Abiraterone acetate plus prednisone is safe and effective in the long term. Early introduction in patients with mCRPC may further increase the survival benefit.