The present invention relates to cabazitaxel for use in a method for treating an AR-V7-positive patient suffering from prostate cancer comprising determining the AR-V7-status in said patient and administering cabazitaxel. The invention also relates to a method of identifying patients with prostate cancer, eligible for treatment with cabazitaxel comprising testing a biological sample from the patient for the presence of AR-V7 circulating tumor cells, wherein the patient is eligible for treatment with said cabazitaxel if circulating tumor cells in said sample test positive for AR-V7. The invention further relates to a kit of parts for determining the AR-V7-status in isolated tumor cells of a patient with prostate cancer.