• 1\. Have a histologically confirmed adenocarcinoma or poorly differentiated carcinoma of the prostate (carcinomas with pure small-cell histology or pure high grade neuroendocrine histology are excluded; neuroendocrine differentiation is allowed).

• 2\. Surgically or medically castrated, with serum testosterone levels of ≤ 50 ng/dL equivalent to 1.7 nmol/L. For patients, currently being treated with luteinizing hormone-releasing hormone (LHRH) agonists, i.e., patients who have not undergone an orchiectomy, therapy must be continued throughout the study.

• 3\. Have evidence of disease progression after prior therapy for mCRPC:

∙ Disease progression after initiation of most recent therapy is based on any of the following criteria:

• Rise in PSA: a minimum of 2 consecutive rising levels, with an interval of ≥ 1 week between each determination. The most recent screening measurement must have been ≥ 2 ng/mL

• Transaxial imaging: new or progressive soft tissue masses on CT or MRI scans as defined by RECIST 1.1

• Radionuclide bone scan: at least 2 new metastatic lesions 4. Signed informed consent obtained prior to initiation of any study-specific procedures or treatment 5. Age ≥ 18 years 6. Life expectancy ≥ 3 months 7. Performance status 0 - 1 8. Adequate organ functions

‣ Hematological: absolute neutrophil count (ANC) \>1.5 x 109/L, platelet count \>100 x 109/L, hemoglobin \> 6,2 mmol/L

⁃ Hepatic: Bilirubin within normal range, aspartate transaminase (AST) and alanine transaminase (ALT) \<2.5 upper normal lever, albumin \> 25 g/L

⁃ Renal: creatinine clearance \>30 mL/min/1.73m2