Climent MA, et al. - A phase II study was designed to assess the efficacy and safety of cabazitaxel (CBZ) as a weekly schedule for ‘unfit’ metastatic castration-resistant prostate cancer (mCRPC) patients after docetaxel failure. When compared to classical standard 3-week scheme (TROPIC study), CBZ/prednisone administered weekly to ‘unfit’ mCRPC patients had similar efficacy but with significantly lower toxicities and better tolerance. Early Circulating tumour cell (CTC) response seemed to be relevant as an early end-point of therapeutic efficacy.