958 - Observational Crossover Study of Cabazitaxel and Abiraterone Acetate in Metastatic Docetaxel-Refractory Castration-Resistant Prostate Cancer (MDR-CRPC)

Abstract

ABSTRACT Purpose In recent years both cabazitaxel (Cbz) and abiraterone acetate (AA) showed to be efficacious treatment options for patients with mDR-CRPC. However, no data exist for patients treated with both these drugs. Aim of our study was to analyze these data in a real world scenario. Material and methods Intention-to-treat (ITT) analysis of activity data deriving from all consecutive patients with mDR-CRPC treated in our unit with prednisone plus Cbz, AA or both. Primary end point of the study was median Progression Free Survival (mPFS), evaluated according to Prostate Cancer Working Group 2 (PCWG2) criteria. Results Here we report characteristics and activity data of 42 patients, 8 treated with Cbz, 24 with AA and 10 with both drugs. The median age of our study population was 70.5 years (range, 55-82), median Gleason Score 8 (4-9) and median ECOG PS 0 (0–3); visceral disease was present in 28 cases (66.7%). The mPFS, according to Kaplan Meier method (KM), was 4.7 months (m) for patients treated with Cbz, not reached for cases treated with AA and 6.7 m for cases treated with both agents. Of the 10 patients treated with both drugs, 6 received a sequence Cbz-AA and 4 a sequence AA-Cbz for an overall median PFS of, respectively, 6.7 and 4.6 m. Conclusions In our limited experience, both Cbz and AA confirmed an intriguing activity in the mDR-CRPC setting. Moreover, both drugs seems to be active also in a sequential use. These data should be verified in large size prospective studies to avoid potential selection biases. Disclosure S. Bracarda: Advisory Board Member for Sanofi-Aventis, Jannsen & Jannsen. Honoraria (Talks) from Sanofi-Aventis. All other authors have declared no conflicts of interest.