Phase Ib neoadjuvant CG0070 and nivolumab (N) for cisplatin (C)-ineligible muscle invasive bladder cancer (MIBC).

Abstract

e16613 Background: CG0070 is a replication-competent oncolytic adenovirus engineered to target RB deficient tumor cells and to express GM-CSF. CG0070 has previously demonstrated safety and efficacy against BCG-exposed high risk non-muscle invasive bladder cancer through tumor lysis and anti-tumor immune activation. We tested the safety and efficacy of CG0070 in combination with N as neoadjuvant therapy for MIBC in C-ineligible patients in this study (NCT04610671). Methods: C-ineligible pts with MIBC (cT2-4a, N≤1) were enrolled. Pts received 6 weekly intravesical CG0070 (1x1012vp) and 2 doses of N at wks 2 and 6, followed by radical cystectomy (RC). The primary objective is safety of CG0070+N as measured by CTCAEv5.0. Secondary objective is to assess pathologic response (PaR) (pT0N0) and 1yr event free survival (EFS). Exploratory objectives include the assessment of correlation between PaR with baseline 1) E2F expression; 2) immune infiltration; 3) PD-L1 expression; and 4) TLS expression. Results: Between Nov 2020 and Feb 2023, 21 pts were enrolled with median age 75yrs, 81% male, 33% > cT2; 1 pt refused RC but was included in the ITT population. Treatment was stopped after 1 infusion of CG0070 in 1 pt due to treatment unrelated worsening of renal function. The overall rate of >grade 3 AEs was 12/20 (60%), and the vast majority were related to RC (83%). Immune related AEs were seen in 1 pt, who had grade 2 autoimmune thyroiditis. There was no delay in time to RC and no unexpected surgical complications from treatment. Overall, 1 pt was unevaluable for efficacy, 2 pts progressed prior to RC, PaR was observed in 8/15 (53%) evaluable pts, and an additional pt had negative post-treatment biopsy but refused RC. On exploratory analysis, treatment response correlated with increased maturation of tertiary lymphoid structures and immunogenicity to bespoke tumor neoantigens. Conclusions: Neoadjuvant CG0070+N is safe and effective in C-ineligible pts with MIBC. This combination was well tolerated without any delays in RC and induced an overall response rate of 50%. Clinical trial information: NCT04610671 .