Patient preference between Cabazitaxel and Docetaxel for first-line chemotherapy in metastatic castrate-resistant prostate cancer (mCRPC): Results from the CABADOC randomized trial

Abstract

Background: Docetaxel and cabazitaxel are taxane chemotherapy approved in men with mCRPC after they demonstrated improved overall survival in first- and second- line, respectively. Recent data suggested similar efficacy when used in the first-line set- ting (Sartor O, ASCO 2016). These two taxanes have different safety profiles. Assessing patient preference between docetaxel and cabazitaxel would contribute to further dif- ferentiate between these two agents. Methods: The CABADOC study is a randomized trial with a cross-over design. Patients with mCRPC were randomized in a 1:1 ratio to receive either docetaxel 75mg/m2/q3w x 4 followed by cabazitaxel 25mg/m2/q3w x 4, or the reverse sequence. Randomisation was stratified based on prior abiraterone or enzalutamide. The primary endpoint was patient preference between taxanes, assessed in patients who had received at least one cycle ofeach taxane and who had not experienced a progression after the first taxane. Prescott’s test was used to analyze the primary endpoint taking into consideration the period effects. Results: From June 2014 to October 2016, 195 patients were randomized in 17 centers. The median age was 70 years and the median PSA was 49 ng/mL. Patients received 3.8 6 0.7 and 3.2 6 1.5 cycles ofchemotherapy during the first and the second period, re- spectively. The eligible population for the primary endpoint comprised 150 patients (45 patients were ineligible for the primary endpoint as per protocol). Among them, 66 preferred cabazitaxel (44% IC95%¼[36-52]), 40 preferred docetaxel (27% IC95%¼[20-34]), and 44 expressed no preference between taxanes (29% IC95%¼ [22-37]) (p¼0.009). A greater proportion ofpatients preferred the first received taxane (44%, IC95%¼[36-52]) versus the second taxane (27%, IC95%¼[20-34]), or had no preference (29% IC95%¼[22-37]). Less fatigue and improved quality oflife were the two main reasons provided by patients for their choice. There were 3 toxicity-related deaths (1.5%). Pharmaco-economic analysis, toxicity, and quality oflife data will be presented. Conclusions: A higher proportion ofmen with mCRPC who are candidates to receive a taxane prefer cabazitaxel over docetaxel. Clinical trial identification: NCT02044354 Legal entity responsible for the study: Gustave Roussy Funding: Sanofi Disclosure: K. Fizazi: Advisory boards/honorarium for Amgen, Astellas, AstraZeneca, Bayer, Clovis, Curevac, Essa, Genentech, Janssen, Orion, Sanofi. G. Gravis: Travels sup- ported by Astellas, Janssen and Sanofi. M. Gross-Goupil: Advisory boards/honorarium for Amgen, Astellas, Janssen, MSD, Sanofi. A. Fle´chon: Honorarium from Astellas, Bayer, Janssen, Sanofi Transportation supported by Pfizer, Sanofi, Astellas, Janssen, MSD, AstraZeneca, Roche, Ipsen, Novartis. All other authors have declared no conflicts ofinterest.