(UroToday.com) The treatment landscape in advanced prostate cancer has rapidly evolved. In the context of metastatic castration resistant prostate cancer (mCRPC), docetaxel was the first agent to demonstrate a survival benefit when combined with conventional androgen deprivation therapy (ADT). Following this, a number of androgen receptor targeting agents have been assessed, beginning with abiraterone acetate and enzalutamide. Despite their overall tolerable risk profiles, some cardiotoxicity signals were reported for these agents in clinical trials but little is known about their incidence in clinical practice. However, these agents haven’t been directly compared in randomized controlled trials.
Thus, in a moderated poster presentation at the American Urologic Association Annual Meeting, Dr. Dragomir and colleagues presented a real-world analysis of the comparative cardiovascular safety of abiraterone acetate and enzalutamide in patients with mCRPC.
To do so, the authors performed a retrospective population-based analysis based on Quebec public healthcare administrative databases. Patients were selected on the basis of having initiated an NHA (abiraterone acetate or enzalutamide) between 2012 and 2016.
They assessed the primary outcome of cardiovascular-related hospitalization (composite outcome of acute coronary syndrome, cerebrovascular stroke, heart failure, arrhythmia, and others). Analytically, inverse probability of treatment weighting (IPTW) with the propensity score was used to adjust for baseline characteristics.
The authors included 2,183 patients, among whom 1,773 (81.2%) received abiraterone acetate and 410 (18.8%) received enzalutamide. The crude incidence rates of cardiovascular-related hospitalization were 9.8 events per 100 person-years (PYs) and of 7.1 events per 100 PYs for the abiraterone acetate and enzalutamide groups, respectively. After accounting for differences in baseline characteristics using IPTW, the abiraterone acetate group was at greater risk of cardiovascular-related hospitalization compared to the enzalutamide group (hazard ratio (HR) 1.82; 95% confidence interval (95%CI) 1.09-3.05). Further, the risk of hospitalization for heart failure was greater in abiraterone acetate (HR 2.88; 95%CI 1.09-7.63).
The authors concluded that, in this population-based analysis, patients treated with abiraterone acetate had an increased risk of cardiovascular-related hospitalizations relative to enzalutamide users, in particular for hospitalization for heart failure.
Presented by: Alice Dragomir, MSc, PhD, Assistant Professor, Department of Surgery, Division of Urology, Faculty of Medicine, McGill UniversityWritten by: Christopher J.D. Wallis, University of Toronto Twitter: @WallisCJD during the 2021 American Urological Association, (AUA) Annual Meeting, Fri, Sep 10, 2021 – Mon, Sep 13, 2021.