Comparison of effectiveness and safety outcomes of abiraterone versus enzalutamide in patients with metastatic castration-resistant prostate cancer: a systematic review and meta-analysis

Abstract

Purpose: To compare the effectiveness and safety between abiraterone and enzalutamide in the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). Methods: We systematically searched for relevant articles from PubMed, Cochrane, Embase from their inception through November 4, 2019. Available articles from conferences were searched. The endpoints were prostate-specific antigen (PSA) response, overall survival (OS), progression-free survival (PFS), number of patients with any adverse event (AE). Results: 15 cohort studies involving 3546 participants were included in this meta-analysis. Pooled result showed that PSA response rate in the enzalutamide group was significantly greater than that in the abiraterone group (867 patients, risk ratio (RR) 0.69, 95% confidence interval (CI) 0.61-0.79, p＜0.00001, I2=29%). There was no significant difference in the total incidence of AEs between two groups (730 patients, RR 0.42, 95% CI 0.14-1.31, p = 0.14, I2=84%). The common adverse events observed in the published articles were fatigue and perceived cognitive impairments. Patients who received enzalutamide had the higher risk to have the feeling of fatigue compared with abiraterone group (2555 patients, RR 0.45, 95% CI 0.24-0.85, p=0.01, I2=92%). And there was no statistical difference between two groups respect to the side effect of perceived cognitive impairments (1856 patients, RR 0.94, 95% CI 0.47-1.88, p=0.85, I2=15%). Conclusions: Our results demonstrated that enzalutamide was associated with higher PSA response rate compared to abiraterone in patients with mCRPC, and no significant difference was found between two groups in the overall AE. But enzalutamide use induced higher risk of the AE of fatigue.