Immune response results of vesigenurtacel-l (HS-410) in combination with BCG from a randomized phase II trial in patients with non-muscle invasive bladder cancer (NMIBC).

319Background: Vesigenurtacel-L (HS-410) is a vaccine comprised of an allogeneic cell line, selected for high expression from a series of bladder tumor antigens, and transfected with gp96-Ig. Cell-secreted gp96-Ig delivers these cell-derived antigens to a recipient's own antigen presenting cells, activating CD8+ cytotoxic T cells. Here we present the secondary immune outcomes from a randomized Phase 2 trial with HS-410 in combination with BCG in NMIBC. Trial ID NCT02010203. Methods: 78 patients with intermediate- (n=5) or high-risk (n=73) NMIBC who are either BCG-naive or recurrent, with or without carcinoma in situ (CIS), were enrolled 1:1:1 to one of two doses of HS-410 (either 106 or 107cells/dose) or placebo in combination with 6 weeks of induction BCG, followed by 6 more weeks of HS-410 in the induction phase. Maintenance treatment consisted of 3-weekly treatments at the following timepoints: 3 mo., 6 mo., 12 mo. Concurrently, 16 patients (1 int. risk, 15 high-risk) were enrolled in an open-label mon...