2. Men, ≥18 years of age with documented asymptomatic or minimally symptomatic metastatic castration- resistant prostate cancer. 3. Castrate testosterone level < 50 ng/dl. 4. Documented progressive disease post -surgical castration or during androgen suppression therapy, or during complete androgen blockade therapy and withdrawal. Documented by either criterion a (Radiological progression), OR criterion b (PSA progression). Protocol BNIT -PRV- 301; Amendment 7 PROSTVAC -V/F Version 2.7, 08 February 2017 CONFIDENTIAL AND RESTRICTED 36 Amend 7 Disclosure requires written consent from Bavarian Nordic , Inc. a. Radiological progression defined as any new/enlarging bone metastases or new/enlarging lymph node disease, consistent with prostate cancer. OR b. PSA progression defined by sequence of rising values separated by > 1 week (2 separate increasing values) over a threshold minimum of 2.0 ng/ml. (PCWG2 P SA eligibility criteria).