"Enzalutamide had a significant impact on all quality of life domains, which was also significant," Dr. Fizazi reported.
Implications for Practice
Dr. Eleni Efstathiou, who was not involved in either trial, put the findings into context.
"Abiraterone acetate is a good drug that, beyond a survival benefit, dose delay pain progression, opiate use, and functional decline even in an asymptomatic, oligosymptomatic, chemotherapy-naive disease setting," said Dr. Efstathiou of the University of Texas M.D. Anderson Cancer Center in Houston.
She added the following caveat: "Severe clinical symptoms may not be reduced proportionally to the effect observed in this patient population."
The AFFIRM data represent the first report of quality of life measures and pain amelioration for enzalutamide, Dr. Efstathiou observed. While provision was made in the study design to assess these as planned secondary outcomes, as with the COU-AA-302 data, the study was not powered to demonstrate their statistical significance.
"Androgen-signaling inhibition does not only prolong life, but also ameliorates bone metastases-associated symptoms in men with metastatic castrate-resistant prostate cancer," Dr. Efstathiou concluded. "However, we cannot claim victory given that severe clinical events may remain unaltered and the reported benefit in this advanced setting, of both trials, is still short lived."
Ortho Biotech Oncology Research & Development sponsored the COU-AA-302 study. AFFIRM was supported by Medivation and Astellas Pharma. Dr. Fizazi has participated in advisory boards for Medivation and Astellas Pharma. Dr. Basch reported no conflicts of interest in relation to the COU-AA-302 study. Dr. Efstathiou had no disclosures.