PROSTVAC (PSA-TRICOM) in Preventing Disease Progression in Patients With Localized Prostate Cancer Undergoing Active Surveillance

PRIMARY OBJECTIVES: I. To determine the effect of rilimogene-galvacirepvec (PROSTVAC) on the change (from pre to post-intervention) in CD8+ positive cells in the stroma adjacent to tumor and within the malignant portion of the prostate biopsies. II. To determine the effect of PROSTVAC on the change in CD4+ positive cells in the stroma adjacent to tumor and within the malignant portion of the prostate biopsies. SECONDARY OBJECTIVES: I. To assess the effect of PROSTVAC on PD-L1 positive cells in the stroma adjacent to tumor and within the malignant portion of the prostate biopsies. II. To assess the correlation between the change in CD8+ and the change in PSA. III. To assess the effect of PROSTVAC on CD8+, CD4+, and PD-L1 positive cells in the benign portion of the prostate biopsies. IV. To assess the effect of PROSTVAC on the change in PSA. V. To assess the effect of PROSTVAC on tumor grade (Gleason score). VI. To assess the effect of PROSTVAC on tumor extent (percent of positive random biopsy cores). VII. To compare the proportion of men on the two study arms with no cancer on post-intervention biopsy. VIII. To assess the effect of PROSTVAC on the size of the dominant lesion on magnetic resonance imaging (MRI) (largest histopathologically confirmed lesion) in the subgroup of patients with MRIs pre and postintervention. IX. To assess the effect of PROSTVAC on circulating 15-Mer PSA-specific, MUC-1 and Brachyury-specific T cells. X. To assess the effect of PROSTVAC on soluble antibodies to tumor-associated antigens. XI. To assess the immunologic effects of PROSTVAC in prostate tissue using multiplex immunofluorescence. XII. To assess the safety and feasibility of PROSTVAC in the active surveillance population. XIII. To assess the effect of PROSTVAC on lower urinary tract symptoms (LUTS) in the active surveillance population. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM I: Patients receive rilimogene-galvacirepvec subcutaneously (SC) at baseline and on days 14, 28, 56, 84, 112, and 140. ARM II: Patients receive placebo SC at baseline and on days 14, 28, 56, 84, 112, and 140. After completion of study treatment, patients are followed up for 30 days and then at 6 months.