LAUSR

371Background: Cabazitaxel monotherapy is a second line treatment option for mCRPC patients. However, not all patients have a PSA response on this treatment, while a proportion of patients develop resistance during cabazitaxel treatment. Platinum drugs might be effective in poorly differentiated disease. Ongoing trials suggest effectivity of the combination in mCRPC, however, thus far clinical parameters cannot predict a response. Therefore, we investigated the addition of carboplatin to cabazitaxel in mCRPC patients who do not have a psa response on cabazitaxel monotherapy or have a PSA rise during treatment. Methods: 19 patients (WHO PS ≤2) who were not responding to ≥2 cycles cabazitaxel monotherapy (25 mg/m2) or two rises of PSA during cabazitaxel were included in this prospective cohort study. All patients received the combination of carboplatin (AUC 4) and cabazitaxel (25 mg/m2). Previous therapies, PSA response, WHO performance score, Progression Free Survival (PFS), Overall Survival (OS) and adver...