Bristol Myers Squibb disclosed that a patient died after receiving its investigational autoimmune CAR-T therapy in a phase 1 trial testing the approach in multiple sclerosis. The patient experienced motor symptoms that did not resolve with standard autoimmune care, received a potent immunosuppressant, then developed septic pneumonia and died, according to the company’s statement. The report arrives amid broader field attention on autoimmune CAR-T safety signals, including disclosures by other developers. For sponsors, the immediate next step is how protocols will be refined—especially around immunosuppression timing, infection risk mitigation, and patient selection. The death also raises expectations among regulators and clinicians for transparent safety monitoring, clearer causality assessment, and more granular adverse-event reporting.