Cabazitaxel in patients aged ≥80 years with castration-resistant prostate cancer: Results of a post-marketing surveillance study in Japan

Objectives: Data on the safety and efficacy of cabazitaxel in patients aged >= 80 years with castration-resistant prostate cancer (CRPC) are limited. We report the safety (adverse drug reactions [ADRs]) and efficacy (overall survival [OS], time to treatment failure [TTF], and prostate-specific antigen [PSA] response rates) in patients aged <80 or >= 80 years treated with cabazitaxel for CRPC in clinical practice. Materials and methods: We performed post-hoc subgroup analyses of a Japanese post-marketing surveillance study involving 662 patients with CRPC treated with cabazitaxel between September 2014 and June 2016. Results: In patients aged <80 (n = 610) and >= 80 years (n = 49), median PSA at baseline was 168.7 and 109.0 ng/mL, and 86.7% and 83.7% of patients were previously treated with enzalutamide and/or abiraterone. ADRs (all grade) occurred in 772% and 79.6% of patients aged <80 and >= 80 years, with grade three/worse ADRs in 61.8% and 63.3% of patients. Hematologic toxicities were the most common grade three/worse ADRs, including neutropenia, febrile neutropenia, and anemia in both subgroups. No specific ADRs were observed in patients aged >= 80 years. The PSA response and median OS and TIT were 28.3%, 292 days, and 116 days in patients aged >= 80 years, and 29.7%, 319 days, and 125 days in patients aged <80 years. Conclusion: Cabazitaxel could be a treatment option for CRPC in patients aged >= 80 years based on its safety and efficacy profiles. This is the first report to investigate the safety and efficacy of cabazitaxel in patients aged >= 80 years with CRPC. (C) 2020 The Authors. Published by Elsevier Ltd.