Survival outcome in patients with metastatic castration-resistant prostate cancer according to first-line treatment

5570 Background: Therapeutic strategy in metastatic castration-resistant prostate cancer (mCRPC) has evolved significantly with the introduction of abiraterone acetate in association with prednisone/prednisolone in first-line treatment in December 2012. This work aimed to compare the effectiveness of abiraterone acetate and docetaxel as first-line treatments for mCRPC, in real-life setting. Methods: Patients with mCRPC were identified in the main scheme of the National Healthcare System database (SNDS), which covers about 86% of the French population, and capturing all reimbursed healthcare expenditures and hospital discharge summaries. Those initiating docetaxel or abiraterone acetate in 1st line in 2014 were included and 1:1 matched on the previous prostate cancer stage before mCRPC status, the delay from the date of initial diagnosis and a high-dimensional propensity score. The 36-month overall survival and the 36-month discontinuation-free survival (i.e. survival time until treatment switch or death) were compared using Cox proportional hazards risk model. Results: In 2014, out of the 12,951 patients with prevalent mCRPC, 1,214 initiated docetaxel in 1st line and 2 444 initiated abiraterone. A total of 716 patients per group were matched with good comparability (C-statistic = 0.6). The median duration of docetaxel–defined as the time between the first and the last infusion–was 7.3 months with a median of 6 infusions. The median duration of abiraterone acetate–corresponding to the period covered by the dispensed drug–was 9.1 months. Near 70% of the docetaxel and 62% of the abiraterone acetate patients received a 2nd line of treatment. Results related to the main survival outcomes are presented in the table below. Conclusions: First-line treatment with abiraterone acetate in mCRPC patients results in a better 36-month overall survival and discontinuation-free survival compared to docetaxel in real-life setting. [Table: see text]