e17605 Background: Metastatic, castration-resistant prostate cancer (mCRPC) is a lethal disease, often preceded by nonmetastatic, castration-resistant phase. Recently, three androgen receptor (AR) antagonists — apalutamide, enzalutamide, and darolutamide — have been approved for nonmetastatic, castration-resistant prostate cancer (nmCRPC). AR-antagonists have been associated with increased risk of hypertension (HTN) and major cardiovascular (CV) events. We conducted a systematic review and meta-analysis of the published phase 3 randomized controlled trials (RCTs) to determine the relative risk of HTN and major CV events associated with use of AR-antagonists for nmCRPC. Methods: We conducted a systematic search at PUBMED, MEDLINE, EMBASE, and meeting abstracts from inception until November 2019. Published phase 3 RCTs using AR-antagonists in the study arm for nmCRPC and reporting the number of events of HTN and major CV events were included in the analyses. We used Mantel-Haenszel (MH) method and random effects model to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was tested with I2 value and Cochran’s Q-test. Results: Three phase 3 RCTs (ARAMIS, PROSPER, and SPARTAN) randomizing 2687 patients in the AR-antagonist arms and 1417 patients in the control arms were included in the final analysis for HTN. SPARTAN did not include data for major CV events; hence, other two studies comprising 2903 patients were analyzed for major CV events. Major CV events included myocardial infraction/coronary artery disease, ischemic/hemorrhagic cerebrovascular events, and heart failure. AR-antagonists used in the study arms were — ARAMIS: darolutamide, PROSPER: enzalutamide, and SPARTAN: apalutamide. Placebo was used in the control arms. All patients continued androgen deprivation therapy. Randomization was 2:1 in all studies. The pooled RR of any-grade HTN is 1.5 (95% CI: 1.03 – 2.18, p = 0.03, I2 = 70%); and, the pooled RR of grade ≥3 HTN is 1.39 (95% CI: 1.03 – 1.88, p = 0.03, I2 = 13%). The pooled RR of any-grade major CV events is 1.49 (95% CI: 1.05 – 2.13, p = 0.03, I2 = 0%); and, the pooled RR of grade ≥3 major CV events is 1.80 (95% CI: 1.11 – 2.92, p = 0.02, I2 = 0%). Conclusions: Our meta-analysis demonstrated use of AR-antagonists for nmCRPC is associated with increased risk of HTN and major CV events. A careful selection of patients and aggressive management of the CV risk factors are crucial to enhance safety and proper utilization of these promising drugs.
Abiraterone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: a systematic review of ‘real-life’ studies