Adverse events of special interest assessed by review of safety data in enzalutamide castration-resistant prostate cancer (CRPC) trials.

Abstract

237 Background: Androgen receptor inhibitor enzalutamide improves survival in patients with metastatic CRPC (mCRPC) and reduces risk of metastasis or death versus placebo in patients with non-metastatic CRPC (nmCRPC). This post hoc analysis evaluated the incidence of adverse events (AEs) of special interest reported with enzalutamide versus placebo in CRPC trials. Methods: Safety data from four Phase 3, placebo-controlled enzalutamide trials in men with CRPC (PROSPER, nmCRPC, NCT02003924; PREVAIL, mCRPC, NCT01212991; AFFIRM, mCRPC, NCT00974311; and 9785-CL-0232, mCRPC, NCT02294461) were assessed for AEs of special interest, including ischemic heart disease (IHD) [defined by narrow Standardised MedDRA Queries “Myocardial Infarction”/“Other Ischemic Heart Disease”], falls, and fractures. Data were reported as overall incidence and adjusted for treatment exposure (per 100 patient-years), and summarized as follows: patients receiving enzalutamide (n = 2799) and placebo (n = 1898) in all four Phase 3 trials. Results: Median treatment duration was 13.73 months with enzalutamide and 4.80 months with placebo in the combined Phase 3 trials. Overall incidence of IHD was higher with enzalutamide versus placebo in the combined Phase 3 trials (Table), remaining higher once adjusted for treatment exposure (2.5 with enzalutamide vs. 2.2 with placebo). Similarly, exposure-adjusted rate of falls and fractures were also higher with enzalutamide versus placebo (Table). Clinical trial information: NCT02003924 (PROSPER); NCT01212991 (PREVAIL); NCT00974311 (AFFIRM); NCT02294461 (9785-CL-0232). Conclusions: In this combined analysis of CRPC trials, incidences of IHD, falls, and fractures were higher with enzalutamide versus placebo in all patients. Efforts to identify patients at high risk for these AEs and reduce their risk, e.g. via exercise and cardiovascular risk reduction, are important in these patients, particularly in elderly men and those with cardiovascular comorbidities.[Table: see text]