Chimeric Therapeutics halted development of its cadherin-17-targeted autologous CAR T program CHM-2101 after a second patient at the highest dose level experienced dose-limiting toxicities. The company said it would discontinue the therapy in its current form and pivot to an early-stage in vivo CAR program targeting the same antigen. The move signals heightened execution risk in solid-tumor CAR T strategies, where safety signals can quickly force modality redesign. For CHM-2101’s team, the pivot aims to shift away from ex vivo manufacturing constraints and toward directly delivered in vivo approaches—while keeping the antigen focus. As CAR T developers broaden beyond hematologic indications, the update highlights the clinical bar for tolerability and the speed at which companies may need to change platform direction based on early safety signals.