Abstract 660P
Background
The optimal choice of second-line post-docetaxel treatment remains unclear. In retrospective single-center study, we compared the efficacy of cabazitaxel (CABA) versus (vs) androgen receptor targeted agents (ARTA), following first-line docetaxel (DOCE) in patients with mCRPC and examined prognostic/predictive factors for selection of second-line treatment option.
Methods
Survival analysis was calculated by the Kaplan-Meier method and the log-rank test was used to test for the differences. The Cox multivariate hazard models were used to calculate hazard ratios (HR) and their 95 % confidence interval (95% CI) in the analysis of overall survival (OS) second-line. Backward variable selection was performed to select independent factors that influence patients OS.
Results
Of 194 patients, 71 received CABA and 124 ARTA in their second-line of treatment. Summary of patients outcomes is presented in the table. The median OS from the initiation of docetaxel did not statistically differ between patients treated with docetaxel-ARTA-other vs docetaxel-CABA-other (27.1 vs 32.8 months). Based on multivariate Cox model, we found, that the presence of liver metastases (HR = 2.505), alkaline phosphatase level elevated over Upper Limit of Normal (ULN) (HR = 1.452) and lactate dehydrogenase level elevated over ULN (HR 1.777) were independent factors influencing OS. A relative treatment benefit for groups with named prognostic factors were found not to be statistically significant (HRCABA vs ARTA = 0.872 (0.630-1.208), p =0.409).
Conclusions
The median OS of DOCE-CABA-other vs DOCE-ARTA-other is numerically in favour to DOCE-CABA-other, but the difference is not statistically significant. Even though liver metastases, alkaline phosphatase and lactate dehydrogenase elevated over ULN, are strong prognostic factors for mOS, they do not predict a differential survival benefit from CABA compared with ARTA in mCRPC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Marina Mencinger.
Funding
Has not received any funding.
Disclosure
M. Mencinger: Advisory/Consultancy: Sanofi; Speaker Bureau/Expert testimony: Janssen; Honoraria (institution), Speaker Bureau/Expert testimony: Astellas; Advisory/Consultancy, Speaker Bureau/Expert testimony: Roche; Honoraria (self): Bayer; Advisory/Consultancy, Speaker Bureau/Expert testimony: Pfizer. T. Ovcaricek: Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Sanofi; Advisory/Consultancy, Speaker Bureau/Expert testimony: Novartis; Advisory/Consultancy, Speaker Bureau/Expert testimony: Pfizer; Advisory/Consultancy, Speaker Bureau/Expert testimony: Roche; Speaker Bureau/Expert testimony: Astellas; Speaker Bureau/Expert testimony: MSD; Speaker Bureau/Expert testimony: Amgen.