Effectiveness, safety and cost of abiraterone acetate in patients with metastatic castration-resistant prostate cancer: a real-world data analysis

New therapies with diverse mechanisms of action are available for metastatic castration-resistant prostate cancer (mCRPC). This study aims to evaluate the effectiveness, safety and cost of abiraterone acetate (AA) in patients with mCRPC.

Observational retrospective cohort study in which mCRPC patients who initiated AA between January 1, 2012 and December 31, 2017, were included. The patients were followed-up until death or March 31, 2018. Demographic, clinical and economic data were collected from the corporate electronic information systems. Survival distributions were estimated using the Kaplan–Meier method and compared using the log-rank test.

A total of 69 mCRPC patients were started on AA, of whom 18 (26.1%) received prior chemotherapy (post-CT) and 51 (73.9%) did not receive it (CT-naïve). A PSA decline of ≥ 50% was achieved in five (27.8%) post-CT and 32 (62.7%) CT-naïve patients (p = 0.011). Median time to PSA progression, progression-free survival (PFS) and overall survival (OS) were 4.4/7.9 months (p = 0.003), 5.1/7.5 months (p = 0.034) and 12.1/21.3 months (p = 0.119), respectively, for post-CT/CT-naïve patients. Treatment-related adverse events (AEs) occurred in 10 (55.6%) post-CT and 11 (21.6%) CT-naïve patients (p = 0.007). The most common AEs were hypokalaemia (11.6%), hypertension (8.7%) and fatigue (5.8%). The cost per median PFS month and per median OS month was €2818.4/€2784.3 and €1187.9/€980.4 for post-CT/CT-naïve patients, respectively.

CT-naïve patients treated with AA obtained a better clinical benefit in terms of effectiveness, safety and cost-effectiveness ratio than post-CT patients. The effectiveness outcomes were poorer than those reported previously in the clinical trial setting.