Weill Cornell Medicine and Roswell Park Comprehensive Cancer Center reported preclinical results showing intravesical CAR T-cell delivery can control bladder tumor growth in mice. The approach targets MUC16, identified by the teams as clinically relevant for bladder cancer. The study, published in Journal of Experimental Medicine, used catheter-based delivery of MUC16-targeting CAR T cells directly into the bladder, aiming to address solid-tumor CAR T limitations such as poor infiltration and off-target toxicity. If the strategy translates clinically, it could support bladder-sparing options in high-risk disease where recurrence and progression drive invasive interventions.