Bristol Myers patient died after CAR-T treatment, company explains June trial pause

On October 23, 2026, Bristol Myers Squibb disclosed that a patient in a Phase 1 trial evaluating zolacabtagene autoleucel for multiple sclerosis died of septic pneumonia 44 days after infusion. The death followed a voluntary trial pause triggered by manufacturing process changes and inflammatory side effects. Meanwhile, Novartis halted eight trials following three deaths. Despite safety concerns, all 60 high-dose zola-cel patients remained off standard MS medications, and Bristol Myers aims to resume enrollment in early 2027 with FDA oversight.

Patient death during CAR-T trial

• ▪A Bristol Myers Squibb spokesperson stated that the zola-cel multiple sclerosis trial patient's prior heavy treatments and late-onset complications confounded efforts to determine the root cause of the fatality
• ▪A patient in Bristol Myers Squibb's zola-cel multiple sclerosis trial developed neurological motor symptoms unresponsive to treatment, prompting administration of high-dose chemotherapy before dying of septic pneumonia the next day
• ▪Bristol Myers Squibb disclosed on October 23, 2026, that a patient in an early-stage multiple sclerosis trial died of septic pneumonia 44 days after receiving experimental CAR-T therapy zolacabtagene autoleucel

Trial pause and manufacturing adjustment

• ▪Bristol Myers Squibb traced its zolacabtagene autoleucel safety concerns to a cell preparation modification during manufacturing and is returning to its original manufacturing process
• ▪Bristol Myers Squibb confirmed that the multiple sclerosis patient's death occurred after the company decided to voluntarily pause enrollment in its zolacabtagene autoleucel trial program
• ▪Bristol Myers Squibb voluntarily paused zolacabtagene autoleucel trials in September 2026 to review safety data after observing transient and reversible inflammatory side effects

Trial efficacy and safety results

• ▪Most multiple sclerosis patients with sufficient follow-up after receiving zolacabtagene autoleucel showed no new disease activity or worsening disability
• ▪All 60 multiple sclerosis patients receiving higher doses of zolacabtagene autoleucel remained off conventional medications at their latest follow-ups, with nine monitored for over a year