Bristol Myers Squibb disclosed that one patient died after receiving its investigational autoimmune CAR-T therapy in an early trial in multiple sclerosis. The patient developed motor symptoms that did not resolve with standard autoimmune treatments, followed by immunosuppressant administration, and then septic pneumonia. The company’s disclosure follows earlier pauses and safety concerns across the autoimmune CAR-T field, highlighting the complexity of immune regulation in neurologic autoimmune contexts. The event is likely to accelerate scrutiny of patient monitoring, management algorithms, and inclusion criteria as sponsors weigh benefit-risk tradeoffs for moving these therapies deeper into clinical development.