The death of the patient with highly active relapsing MS occurred after the study’s data cutoff.
- Bristol Myers stated that no other deaths have been reported across its broader zola-cel autoimmune disease programs, which have treated 190 patients in early-stage studies.
- A company spokesperson told Bloomberg that the death occurred after the company’s decision to pause enrollment in the program.
- The study in question included 66 patients who had ongoing disease activity or worsening disability despite prior treatments.
Shares of Bristol Myers Squibb (BMY) dropped 2% on Friday after the company disclosed a patient death in its early-stage Breakfree-2 study of the experimental CAR T cell therapy, zolacabtagene autoleucel, for multiple sclerosis.
The death of the patient with highly active relapsing MS occurred after the study’s data cutoff. The patient developed late-onset motor symptoms that were not related to immune effector cell-associated neurotoxicity syndrome (ICANS) and did not improve with intermittent corticosteroids or intravenous immunoglobulin, the company said. Doctors administered a high-dose immunosuppressant drug, and the patient then developed septic pneumonia and died the next day—44 days after receiving the zola-cel infusion, it added.
Bristol Myers stated that no other deaths have been reported across its broader zola-cel autoimmune disease programs, which have treated 190 patients in early-stage studies.
Safety Concerns Build Around CAR T Therapies
The disclosure comes amid heightened scrutiny of CAR T therapies in autoimmune diseases. Bristol Myers had voluntarily paused enrollment in its zola-cel studies in September “out of an abundance of caution” while reviewing safety data, following Novartis’s earlier pause of multiple trials of a similar therapy after fatal events.
A company spokesperson told Bloomberg that the death occurred after the company’s decision to pause enrollment in the program.
Other Safety Events Observed In The Trial
Most adverse events in the multiple sclerosis cohorts were short-lived and reversible, consistent with prior zola-cel data, Bristol Myers said. Cytokine release syndrome occurred in 42.4% of the 66 patients, and ICANS affected 7.6%, with nearly all cases resolving within days. A more serious ICANS event in a progressive MS patient resolved within four days, the company added
Breakfree-2 study included 66 patients who had ongoing disease activity or worsening disability despite prior treatments. Safety was the primary endpoint.
Even with the safety issues, the early efficacy results looked encouraging. All 60 patients who received the higher dose stayed off their regular MS drugs at the last check, including nine who had been followed for more than a year.
Among patients with at least six months of follow-up, six of seven with highly active relapsing MS showed no evidence of disease activity. All eight evaluable relapsing patients had stable or better disability scores. And 22 of 24 progressive MS patients also had stable or improved disability, with no new lesions on MRI scans.
How Did BMY Retail Traders React?
On Stocktwits, retail sentiment around BMY stock stayed within the ‘bullish’ territory over the past 24 hours while message volume jumped from ‘low’ to ‘normal’ levels.
BMY stock has gained 14% year-to-date.
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