Ronald de Wit, MD
The number of docetaxel cycles completed was associated with improved overall survival among men with metastatic castration-resistant prostate cancer receiving docetaxel, prednisone, and lenalidomide (Revlimid) or docetaxel/prednisone, in the phase III Mainsail trial. de Morrée et al reported this post hoc analysis in JAMA Oncology.1
In the Mainsail trial, 1,059 patients were randomized to receive docetaxel/prednisone/lenalidomide or docetaxel/prednisone plus placebo until disease progression or unacceptable toxicity. Median overall survival was significantly poorer in the docetaxel/prednisone/lenalidomide group. Due to greater toxicity, patients in the docetaxel/prednisone/lenalidomide group received fewer docetaxel cycles (median of 6 vs 8); docetaxel dose intensity was similar in the two groups. In the current analysis, the effect of the number of docetaxel cycles on overall survival was evaluated in the intent-to-treat population.
Association With Survival
On multivariate analysis including all patients, receipt of ≥ 8 cycles of docetaxel was associated with improved overall survival (hazard ratio [HR] = 1.909, P < .001), whereas the treatment group was not significantly associated with survival (HR = 1.060, P = .41, for docetaxel/prednisone/lenalidomide vs docetaxel/prednisone). In a sensitivity analysis, median overall survival was 33.0 months in patients receiving > 10 cycles, 26.9 months in those receiving 8 to 10 cycles, and 22.8 months in those receiving 5 to 7 cycles (P < .001 overall).
The investigators concluded: “These findings suggest that continuation of docetaxel chemotherapy contributes to the survival benefit. Prospective validation is warranted.” ■
Ronald de Wit, MD, of Erasmus MC Cancer Institute, is the corresponding author of the JAMA Oncology article.
Disclosure: This study was supported by the Celgene Corporation. Dr Vogelzang has served in a consultant or advisory relationship for the Celgene Corporation and Veridex and in an employment or leadership position for US Oncology Research. Dr Petrylak has served in a consultant or advisory relationship for the Celgene Corporation and has received research funding from the Celgene Corporation and Sanofi-Aventis. Drs Bellmunt, Sternberg, and De Wit have served in a consultant or advisory relationship for the Celgene Corporation and Sanofi-Aventis. Dr Gschwend has served in a consultant or advisory relationship for the Celgene Corporation. Drs Barton, Fandi, Jungnelius, S. Li, and J. S. Li have served in employment or leadership positions for the Celgene Corporation and own stock from Celgene Corporation.
1. de Morree ES, Vogelzang NJ, Petrylak DP, et al: Association of survival benefit with docetaxel in prostate cancer and total number of cycles administered. A post hoc analysis of the Mainsail study. JAMA Oncol. August 25, 2016 (early release online).