Weill Cornell Medicine and Roswell Park Comprehensive Cancer Center reported preclinical evidence that intravesical CAR T-cell delivery can control bladder tumors in mice. In a Journal of Experimental Medicine study, researchers engineered CAR T cells targeting MUC16 and delivered them directly into the bladder via catheter administration. The team, led by Taha Merghoub, PhD, identified MUC16 as a clinically relevant target and showed tumor control with the intravesical approach, framing catheter-based delivery as a potentially simpler, more implementable alternative to systemic CAR T deployment for solid tumors. Because CAR T therapies have historically struggled in solid tumors due to infiltration and toxicity barriers, MUC16-focused, locally administered CAR T could become a template for bladder-sparing strategies—especially for patients facing high recurrence after standard interventions.