Phase I dose escalation trial of MVA-BN-PRO in men with nonmetastatic castration-resistant prostate cancer.

193 Background: MVA-BN-PRO is an investigational prostate cancer immunotherapy comprising of a highly attenuated non-replicating vaccinia virus engineered to encode prostate specific antigen (PSA) and prostate acid phosphatase (PAP) proteins. Preclinical studies in mouse tumor models demonstrated vaccine-mediated induction of anti-PSA and PAP specific immune responses and anti-tumor activity. Results of the open-label multi-center evaluation in subjects with non-metastatic castration resistant prostate cancer are presented. Methods: Eligible subjects had documented prostate cancer with a rising PSA while on androgen suppression therapy and were chemotherapy naive. Three cohorts of subjects were immunized subcutaneously receiving either 1, 2 or 4 injections of study drug (1 injection = 1×108 tissue culture infectious dose, TCID50) at monthly intervals for three months (treatment). If the vaccinations were tolerated, re-treatment with an additional 3 monthly vaccinations was administered at the same dose. R...