Optimal Sequencing of Treatment Options for Poor Risk mCRPC Previously Treated With Docetaxel

Rationale: The aim of this study is to identify the optimal second line treatment option for patients with a poor prognosis metastasized Castration Resistant Prostate Cancer (mCRPC) with respect to Clinical Benefit Rate (CBR) rate and quality of life. Objective: The primary endpoint is CBR in mCRPC patients with poor prognostic features and previously treated with docetaxel, randomized between cabazitaxel (Arm A) and novel hormonal agents (abiraterone OR enzalutamide) as second-line therapy (Arm B). Study design: a prospective, multicenter, national, randomized, open label phase IIB study. Study population: Males over 18 years with mCRPC, previously treated with docetaxel and features of poor prognostic disease; including duration of response to androgen deprivation shorter than one year, liver metastases, disease progression during docetaxel treatment or within 6 months after docetaxel treatment completion. Intervention: Patients in Arm A will receive cabazitaxel and prednisone and patients in Arm B will receive abiraterone and prednisone OR enzalutamide. Main study parameters/endpoints: Primary endpoint: Clinical benefit rate (CBR). Secondary endpoints include: formal comparison of the CBR in both study arms, Time To Symptomatic Progression (TTSP), Time To PSA (prostate specific antigen), Progression (TTPP), and Time To Radiologic Progression (TTRP), progression free survival, overall survival, safety/ toxicity profile and Quality of Life (QoL) and pain response. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Treatment regimens evaluated in this trial are used in common mCRPC treatment practice and are reimbursed. Risk of side effects or death as a result of treatment is not affected by the trial design. At baseline, prior to each treatment cycle and at end of treatment, patients are requested to visit the out-patient clinic, where a physical exam will be performed in combination with vena puncture for blood analysis. Radiological evaluation will be performed at base line, after 3 months of treatment and at end of treatment. All above mentioned interventions can be considered as standard practice. Patients are requested to fill out QoL and pain/analgesic use questionnaires at base line, prior to each cycle and at end of treatment.