Patient Dies in Bristol Myers’ Autoimmune CAR-T Study

WHO:

STAT - Bristol Myers Squibb reported the patient’s death and said the patient had received its investigational CAR-T therapy.

STAT - The patient was enrolled in a Phase 1 trial testing the therapy in people with multiple sclerosis.

STAT - Elaine Y. Chen covers obesity treatments, drug payment models, FDA-related company impacts and psychedelics; she co-writes STAT’s The Readout newsletter and co-hosts its biotech podcast, The Readout Loud.

WHAT:

STAT - Bristol Myers Squibb reported that a patient died after receiving its investigational autoimmune CAR-T therapy.

STAT - The patient developed motor symptoms that did not resolve with standard autoimmune treatments, then received a potent immunosuppressant, developed septic pneumonia and died.

STAT - Bristol Myers Squibb said the patient had been treated for a series of other complications before receiving CAR-T therapy.

STAT - Bristol Myers Squibb said those complications were “confounding our ability to determine the root cause of the issue.”

Endpoints News - The article headline reports a death in Bristol Myers Squibb’s multiple sclerosis CAR-T trial and says the company had an answer for a safety signal in a lupus trial.

WHY:

STAT - Bristol Myers Squibb said the patient’s prior complications made it difficult to determine the root cause of the issue.

STAT - The report said the death added to safety concerns about the growing field of autoimmune CAR-T research.

HOW:

STAT - The therapy was being tested in a Phase 1 trial for multiple sclerosis, a condition described as causing muscle weakness and extreme fatigue.

STAT - After the patient’s motor symptoms did not resolve with standard autoimmune treatments, clinicians administered a potent immunosuppressant; the patient subsequently developed septic pneumonia.

Endpoints News - The article identifies the study as an autoimmune CAR-T study involving multiple sclerosis and references a safety signal in a lupus trial.

(UPDATED October 24, 2026 04:07 UTC)

A patient has died after receiving Bristol Myers Squibb’s investigational CAR-T therapy in a Phase 1 trial for multiple sclerosis, raising further safety concerns around autoimmune CAR-T research. The company said the patient developed motor symptoms that did not improve with standard autoimmune treatments. Clinicians then gave the patient a potent immunosuppressant, after which the patient developed septic pneumonia and died. Bristol Myers Squibb also said the patient had experienced a series of other complications before receiving the therapy. Those complications, the company said, are “confounding our ability to determine the root cause of the issue.” The trial is testing the therapy in people with multiple sclerosis, a condition that can cause muscle weakness and extreme fatigue. The report also references a safety signal in a separate lupus trial.