Safety of abiraterone acetate (AA) in castration-resistant prostate cancer (CRPC) patients with concomitant cardiovascular disease.

Abstract

168 Background: Abiraterone acetate (AA) is an inhibitor of extragonadal androgen biosynthesis that prolongs overall survival in CRPC patients who have received a chemotherapy including docetaxel. The most common adverse events related to AA therapy were fluid retention, hypertension, hypokaliemia and cardiac disorders. No safety data are available in patients with concomitant cardiac disease. Methods: Metastatic CRPC patients were enrolled in this prospective study if they were also suffering from a concomitant controlled cardiovascular disease. AA 1000 mg per day and prednisone 5 mg bid were administered orally until grade 3-4 adverse events (AE) or disease progression. The primary endpoint was the safety profile while the secondary endpoints were progression-free survival and PSA response. Results: From April to September 2011, 33 CRPC patients with concomitant cardiovascular disorders have been treated with AA. Main patients characteristics were: median age 71 years (range 57–81); baseline mean PSA value 40 ng/ml (6.32-995); the most common sites of disease were bone (27 pts, 81%), lung (11 pts, 33%) and liver (5 pts, 15%). All patients were previously challenged with at least 2 lines of hormone therapy and 1 chemotherapy regimen including docetaxel. The most common pre-existing cardiac disorders were hypertension 22 (66%), arrhythmias 4 (12%), cardiac ischemia 3 (9%) and conduction irregularity 2 (4%). Additionally 9 patients (27%) had metabolic disorders including dislipidemy and hyperglicemia. AA was feasible without inducing grade 3-4 AE nor treatment modification. The most common grade 1-2 AE were asthenia (27%), hypertension (18%) and fluid retention (28%). After a median time of treatment of 4 months (range 2–7 months) no dose modifications due to toxicity were required. No efficacy data are still available. Conclusions: Treatment with AA was feasible and well tolerated also in patients suffering from cardiac comorbidities and risk factors for cardiovascular disease.