Cardiovascular and Metabolic Toxicity of Abiraterone in Castration-resistant Prostate Cancer: Post-marketing Experience

IntroductionAbiraterone improves survival in metastatic castration-resistant prostate cancer (mCRPC) but may result in the development or worsening of comorbid conditions. We assessed the course of these conditions in patients receiving abiraterone in clinical practice and compared outcomes with those in clinical trials.Materials and MethodsMedical records of patients with mCRPC who started abiraterone at an academic institution between 2012 and 2015 were reviewed for emergency department (ED) visits, hospitalizations, and the development and/or worsening of key comorbid conditions while on abiraterone. Patient characteristics and adverse events were compared with those from clinical trials.ResultsIn a cohort of 174 patients, 28% experienced either the development or worsening of a comorbid disease; 8% required an ED visit or hospitalization owing to known adverse effects of abiraterone. Increasing age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.01-1.17), higher prostate-specific antigen at initiation of treatment (OR, 1.68; 95% CI, 1.18-2.47), preexisting uncontrolled hypertension (OR, 7.61; 95% CI, 1.22-38.70), congestive heart failure (OR, 7.61; 95% CI, 1.22-38.70), and cardiac arrhythmias (OR, 4.73; 95% CI, 1.39-15.12) were associated with increased odds of an ED visit or hospitalization owing to known adverse effects of abiraterone. The rate of discontinuation (6%) was similar to 1 phase III trial that demonstrated the drug’s efficacy in chemotherapy-naive patients.ConclusionFew patients discontinued abiraterone owing to toxicity; however, the fact that over one-quarter of patients experienced the development or worsening of cardiovascular and metabolic diseases warrants development of team-based approaches to the management of these comorbid conditions.