Evaluation of the efficacy and safety of cabazitaxel in combination with prednisone in patients with metastatic castration-resistant prostate cancer who have previously received docetaxel chemotherapy in daily clinical practice. Results of a Russian multicenter prospective study
Authors: Alekseev B. Ya. , Shevchuk I. M. 
Published: April 2020

Materials and methods. From September 19, 2016 to December 27, 2019, 104 patients received cabazitaxel plus prednisone for a maximum of 10 cycles or disease progression, or unacceptable toxicity, or patient request to stop treatment. Adverse events occurring during treatment, including use of granulocytic colony stimulating factors, were collected. Prostate specific antigen response, objective tumor response (RECIST), progression-free survival and overall survival were analyzed. Treatment period was followed by a follow-up period of 82.0 (36.0–117.0) weeks.

Results. 104 patients with histologically proven adenocarcinoma were enrolled and treated. All were Caucasian with a median age of 66 (range 46.0–86.0) years and a median BMI-Score of 26.8 (18.7–43.3) kg/m2. Most patients (57/104, 54.8 %) were ECOG 1. At the time of prostate cancer diagnosis, 63/104 (60.6 %) patients had metastatic disease. The median duration of therapy was 14.5 (0.1–39.0) weeks and the median number of cycles cabazitaxel was 5; 30 (28.8 %) patients received 10 cycles of treatment. Granulocytic colony stimulating factors was received by 52 (50.0 %) patients (prophylactic, n = 31; curative, n = 21). Overall, 102/104 (98.08 %) patients reported at least one treatment emergent adverse event (TEAE), 21/104 (20.19 %) grade ³III TEAEs and 12/104 (11.54 %) serious adverse events. Most TEAEs resolved but 9/104 patients discontinued treatment due to TEAE. Most common TEAEs were related to gastrointestinal system disorders (46/104 (44.23 %) patients, mainly nausea n = 40); blood and lymphatic system disorders (44 (42.31 %) patients, mainly leukopenia n = 22, anemia n = 15, neutropenia n = 11) and general disorders/administration site conditions (22 (21.15 %) patients; mainly asthenia n = 21). Main grade ³III adverse events were related to blood and lymphatic system disorders (11 (10.58 %), including one case of febrile neutropenia), general disorders/administration site conditions (6 (5.77 %), mainly asthenia) and cardiac disorders in 2 (1.92 %) patients. A prostate specific antigen decline of at least 50 % was observed in 23 out of 31 patients with evaluable prostate specific antigen measurements. The objective tumor response was observed in 29 (27.9 %) patients, including 7 (6,7 %) with complete response and 22 (21.2 %) with partial response. Treatment was completed as initially planned in 41/104 (39.4 %) patients, and 61/104 (58.7 %) reached the last follow-up visit. At the last follow-up visit, median overall survival was not reached due to a low number of events. Median progression-free survival at the end of treatment visit was 6.29 (5.1–10.45) months and reached 10.13 (5.55–19.27) months at the last follow-up visit. There was no reported death related to treatment of cabazitaxel during the period of treatment and follow-up period.

Conclusion. This prospective, multi-center, national observational, non-interventional register conducted in patients with mCRPC in Russian Federation suggests that cabazitaxel is effective with a manageable safety profile.