Chimeric Therapeutics halted its phase I/II study of CHM-2101, a cadherin-17-targeted autologous CAR T for gastrointestinal cancers, after dose-limiting toxicities occurred in a second patient at the highest dose level. The company said it will discontinue the therapy in its current form. Chimeric will pivot toward an early-stage in vivo CAR program targeting the same antigen, reflecting a strategy shift to reduce manufacturing and patient burden while attempting to address tolerability challenges seen in the autologous approach. The decision is a notable setback for CAR T candidates targeting solid tumors, where efficacy and safety often remain tightly linked to construct design and delivery method. It also raises the bar for follow-on programs to demonstrate improved therapeutic window. For biotech observers, the change illustrates how quickly companies are adapting when emerging clinical signals constrain development paths.