Overall Survival Among Chemotherapy-Naive Patients With Castration-Resistant Prostate Cancer Under Abiraterone Versus Enzalutamide: A Direct Comparison Based on a 2014–2018 French Population Study (the SPEAR Cohort). Issue 3 (18th September 2020)

• Record Type: Journal Article
• Authors: Scailteux, Lucie-Marie; Campillo-Gimenez, Boris; Kerbrat, Sandrine; Despas, Fabien; Mathieu, Romain; Vincendeau, Sébastien; Balusson, Frédéric; Happe, André; Nowak, Emmanuel; Oger, Emmanuel
• Is Part Of: American journal of epidemiology. Volume 190:Issue 3(2021)
• Page Start: 413
• Page End: 422
• Publication Date: 2020-09-18
• Subjects: abiraterone -- enzalutamide -- metastatic castration-resistant prostate cancer -- overall survival -- population-based study -- SNDS; Epidemiology -- Periodicals; Public health -- Periodicals; 614.4
• DOI: 10.1093/aje/kwaa190
• Languages: English
• ISSNs: 0002-9262

Abstract

Abstract: Abiraterone acetate (ABI) and enzalutamide (ENZ) are considered to be clinically relevant comparators among chemotherapy-naive patients with castration-resistant prostate cancer. No clinical trials comparing overall survival with ABI versus ENZ in a head-to-head approach have been published so far. A few observational studies with low power suggested a potential benefit of ENZ. We used the French National Health Data System to compare overall survival of new users of ABI and ENZ among chemotherapy-naive patients with castration-resistant prostate cancer in 2014–2017, followed through 2018 (the SPEAR cohort, a 2014–2018 cohort study). With an intent-to-treat approach, a survival analysis was performed, estimating hazard ratios for overall survival with the inverse probability weighted Cox model method. Among 10, 308 new users, 64% were treated with ABI and 36% with ENZ. The crude mortality rate was 25.2 per 100 person-years (95% confidence interval (CI): 24.4, 26.0) for ABI and 23.7 per 100 person-years (95% CI: 22.6, 24.9) for ENZ. In the weighted analysis, ENZ was associated with better overall survival compared with ABI (hazard ratio = 0.90 (95% CI: 0.85, 0.96) with a median overall survival of 31.7 months for ABI and 34.2 months for ENZ). When restricting to 2015–2017 new users, the effect estimate shifted up to a hazard ratio of 0.93 (95% CI: 0.86, 1.01).