Sequencing Radium 223 (Ra223) For Metastatic Castration-Resistant Prostate Cancer (Mcrpc) Patients (Pts) In The Daily Practice: Preliminary Results From A Retrospective Study In Italian Centers.

322Background: The potential advantage of the sequential use of the active drugs (ADs) able to prolong overall survival (OS) in mCRPC (abiraterone, cabazitaxel, docetaxel, enzalutamide, RA223) could be limited by the development of common mechanisms of resistance. According to its unique targeted alpha-radiation mechanism of action, it could be postulated that RA223 does not induce and is not affected by cross-resistance with other agents and consequently its incorporation in therapeutic sequences may improve clinical outcomes. The present study is aimed to describe the clinical outcomes of pts who received RA223 and at least two other ADs for mCRPC. Methods: We collected data of pts who received sequentially 3 or more ADs of which one was RA223. For each pt we recorded the clinical outcome of all treatments received for mCRPC. We also compared the cumulative survival from the start of the first line to that of a contemporary series of 405 mCRPC pts without visceral mets sequentially treated with 3 or 4 A...