Real-world Outcomes of Sequential Androgen-receptor Targeting Therapies with or Without Interposed Life-prolonging Drugs in Metastatic Castration-resistant Prostate Cancer

_Background:_ Cross resistance between androgen-receptor targeting therapies(ARTs) (abiraterone acetate plus prednisone [ABI + P] or enzalutamide [ENZ]) fortreatment of metastatic castration-resistant prostate cancer (mCRPC) may affectresponses to second ART (ART2). _Objective:_ To establish treatment duration and prostate-specific antigen (PSA)response of ART2 in real-world mCRPC patients treated with or without otherlife-prolonging drugs (LPDs; ie, docetaxel, cabazitaxel, or radium-223) betweenART1 and ART2. _Design, setting, and participants:_ Castration-resistant prostate cancer patients,diagnosed between 2010 and 2016 were retrospectively registered in Castra-tion-resistant Prostate Cancer Registry (CAPRI). Patients treated with both ARTswere clustered into two subgroups: ART1 > ART2 or ART1 > LPD > ART2