Patient Preference Between Cabazitaxel and Docetaxel for First-line Chemotherapy in Metastatic Castration-resistant Prostate Cancer: The CABADOC Trial

Background: The taxanes docetaxel and cabazitaxel prolong overall survival for men with metastatic castration-resistant prostate cancer (mCRPC), with cabazitaxel approved in the postdocetaxel setting only. Recent data suggest they have similar efficacy but a different safety profile in the first-line mCRPC setting. Objective: To assess patient preference between docetaxel and cabazitaxel among men who received one or more doses of each taxane and did not experience progression after the first taxane. Design, setting, and participants: Chemotherapy-naïve patients with mCRPC were randomized 1:1 to receive docetaxel (75 mg/m² every 3 wk × 4 cycles) followed by cabazitaxel (25 mg/m² every 3 wk × 4 cycles) or the reverse sequence. Randomization was stratified by prior abiraterone or enzalutamide use. Outcome measurements and statistical analysis: The primary endpoint was patient preference, assessed via a dedicated questionnaire after the second taxane. Secondary endpoints included reasons for patient preference, prostate-specific antigen response, radiological progression-free survival, and overall survival. This clinical trial is registered at ClinicalTrials.gov as NCT02044354. Results and limitations: Of 195 men randomized, 152 met the prespecified modified intent-to-treat criteria for analysis. Overall, 66 patients (43%) preferred cabazitaxel, 40 (27%) preferred docetaxel, and 46 (30%) had no preference (p = 0.004, adjusted for treatment period effect). More patients preferred treatment period 1 (43%, 95% confidence interval [CI] 36–52%) versus period 2 (27%, 95% CI 20–34%). Patient preference for cabazitaxel was mainly related to less fatigue (72%), better quality of life (64%), and other adverse events (hair loss, pain, nail disorders, edema). Adverse events were consistent with the known safety profile of each drug. Conclusions: A significantly higher proportion of chemotherapy-naïve men with mCRPC who received both taxanes preferred cabazitaxel over docetaxel. Less fatigue and better quality of life were the two main reasons driving patient choice. Patient summary: Men with metastatic castration-resistant prostate cancer preferred cabazitaxel over docetaxel for chemotherapy, mainly because of less fatigue and better quality of life.