A phase II clinical trial of neoadjuvant sasanlimab and stereotactic body radiation therapy as an in situ vaccine for cisplatin-ineligible MIBC: the RAD VACCINE MIBC trial.

The utilization of neoadjuvant immune checkpoint inhibitor therapy, specifically anti-PD-1/L1 agents, prior to radical cystectomy is an emerging paradigm in muscle-invasive bladder cancer (MIBC). In situ vaccination represents a strategy to manipulate the tumor in order to augment the immune response toward improved local and distant cancer control. The authors describe the study rationale, design and objectives for RAD VACCINE MIBC, a single-arm, single-institution, phase II trial evaluating the efficacy and safety of combination neoadjuvant sasanlimab (humanized IgG monoclonal antibody that targets PD-1) with stereotactic body radiotherapy as an in situ vaccine in cisplatin-ineligible patients with MIBC. The results from this trial will establish the safety profile of this combination strategy and evaluate pathologic complete response rates.