Meaningful survival after cabazitaxel in patients with metastatic castration-resistant prostate cancer (mCRPC): The Spanish experience.

Abstract

235 Background: New emerging therapies for metastatic castration resistant prostate cancer (mCRPC), such as cabazitaxel (CBZ), have prompted the need to identify appropriate patients (pts) for each specific treatment. We describe preliminary data on the experience with CBZ in patients (pts) with mCRPC in Spain. Methods: Medical records from docetaxel-resistant mCRPC pts receiving CBZ at 15 centers in Spain were reviewed retrospectively. Baseline characteristics, PSA response, overall survival (OS), radiographic progression-free survival (rPFS), and toxicity were collected. Results: Data from 79 consecutive pts (median age 70) were reviewed: Eastern Cooperative Oncology Group (ECOG) zero to one (87.3%), Gleason score of 7 to 10 (87.1%), visceral involvement (24.1%), pain (74.7%), and radiological progression (68.4%) at CBZ initiation. Median duration of response to first-line androgen deprivation therapy was 20.8 months (mo). Most pts received less than or equal to two hormonal lines (72.2%) and only one docetaxel line (74.7%) before CBZ. Thirty-five (44.3%) pts had progressed on docetaxel. Progression less than six mo or greater than six mo after last docetaxel treatment was observed in 23 (29.1%) and 21 (26.6%) pts, respectively. New hormonal agents (abiraterone or enzalutamide) were given before CBZ in 2.5% of pts and after CBZ in 17.7%. Pts received a median of seven cycles (range 2 to 22) of CBZ. CBZ dose-reductions or -delays for any cause occurred in eight (10.1%) and 20 (25.3%) pts, respectively. Prophylactic G-CSF was given in 32 (40.5%) pts. A PSA decrease of greater than or equal to 50% and greater than or equal to 30% was reached in 41.2% and 48.6% of pts treated with CBZ. Median OS from first CBZ cycle was 16.2 [CI: 10.4;-] mo and median clinical and/or radiographic progression-free survival (rPFS) was 9.9 mo [CI: 7.4; 13.1]. Fourteen (17.7%) pts experienced at least one grade greater than or equal to 3 treatment-related AE, the most common being neutropenia (n=4), febrile neutropenia (n=2), asthenia (n=4), and diarrhoea (n=2). No grade greater than or equal to 3 peripheral neuropathy was reported. An analysis of factors predicting outcome will be presented. Conclusions: CBZ administered in real-life practice and in the adequate treatment setting in Spain is associated with meaningful PFS and OS and an acceptable safety profile. Dose delays and reductions were low. Prophylactic G-CSF use in 4 out of 10 pts may have contributed to these good results.