Bristol Myers Squibb disclosed that one patient died following treatment in an early autoimmune CAR-T Phase 1 trial targeting multiple sclerosis. The company said the patient experienced motor symptoms that did not resolve with standard autoimmune treatments, was then given a potent immunosuppressant, and later developed septic pneumonia. The report follows prior disclosures of safety concerns in autoimmune CAR-T programs, including a pause by Bristol Myers on its therapy after observing transient and reversible inflammatory events during routine surveillance, and similar developments involving Novartis’ autoimmune CAR-T studies. The incident matters for developers and investors because it highlights the clinical management challenges of balancing immune suppression and infection risk in CAR-T settings where autoimmune toxicities can require aggressive intervention.