Survival outcomes from a cumulative analysis from worldwide observational studies on sequential use of new agents (NAs) in metastatic castration-resistant prostate cancer (mCRPC) (CASTOR study).

5026Background: After the introduction in the daily clinical practice of cabazitaxel (CABA) and new hormone agents (NHAs), abiraterone acetate (AA) and enzalutamide (ENZ), several small retrospective reports described their activity when sequentially used as second- and third-line after docetaxel (DOC) failure. Data from survival plots suggested that after DOC, CABA-based sequences led to a better overall survival (OS) than sequences based on NHAs only. The present work is based on individual-data analysis from some of the published reports on sequential use of at least two NAs after DOC. Methods: All authors of the published papers meeting the study criteria were prompted to provide individual data of the pts evaluated in their work. We calculated the overall survival (OS) from the second-line start by sequence strategy. For the OS analysis we considered three different types of NAs sequences after DOC: one new hormone agent (AA or ENZ) followed by CABA (NHA→CABA); CABA followed by AA or ENZ (CABA→NHA); ...