Consistent Benefit Survival with Cabazitaxel (CBZ) in Metastatic Castration Resistant Prostate Cancer (mcrpc) in Spain: Updated Results.

e16088 Background: New emerging therapies for mCRPC, such as CBZ, have prompted the need to identify appropriate patients (pts) for each specific treatment. Updated data on the experience with CBZ in mCRPC pts in Spain with longer follow-up is presented. Methods: Medical records from docetaxel-resistant mCRPC pts receiving CBZ at 19 centres in Spain were reviewed retrospectively. Baseline characteristics, PSA response, overall survival (OS), radiographic progression-free survival (rPFS), and toxicity were collected. Results: Data from 99 consecutive pts (median age 70 years) were reviewed: ECOG 0-1 (77.2%), Gleason score of 7-10 (83.6%), visceral involvement (24.5%), pain (72.7%) and radiological progression (69.7%) at CBZ initiation. Median duration of response to first-line androgen deprivation therapy (ADT) was 20.8 months (mo). Most pts received ≤2 hormonal lines (77.8%) and only one docetaxel line (76.8%) before CBZ. Forty-three (43.4 %) pts had progressed on docetaxel, 31 (31.3%) <6 mo and 25 (25.3%) >6 mo after docetaxel. Abiraterone or enzalutamide were given before CBZ in 5.1% of pts and after CBZ in 15.2%. Pts received a median of 6 cycles (interquartile range 4-9) of CBZ. CBZ dose-reductions or -delays for any cause occurred in 10 (10.1%) and 26 (26.3%) pts, respectively. Prophylactic G-CSF was given in 40 (40.4%) pts. A PSA decrease of ≥50% and ≥30% was reached in 38.1% and 46.4 % of pts treated with CBZ. Median OS from first CBZ cycle was 16.1 [CI: 11.4; 18.1] mo and median clinical and/or rPFS was 10.6 mo [CI: 7.5 ; 13.1]. Seventeen (17.2%) pts experienced at least one grade≥3 treatment-related AE, the most common being neutropenia (n=5), febrile neutropenia (n=2), asthenia (n=4), diarrhoea (n=2) and anemia (n=2). No grade ≥3 peripheral neuropathy was reported. An analysis of factors predicting outcome and the impact of gleason > 8 and time under ADT will be presented. Conclusions: CBZ administered in the adequate treatment setting in daily practice 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 40% pts may have contributed to these good results. Funding: Sanofi.