Novartis, Bristol Myers halt autoimmune CAR-T trials after deaths

Novartis paused eight clinical trials of its experimental cell therapy rap-cel targeting autoimmune and neurological disorders after three patients died from a life-threatening immune reaction, according to Reuters. Bristol Myers has also voluntarily halted enrollment in its own competing CAR-T trials as a precaution.

The Swiss drugmaker said it initiated the hold on Aug. 24 upon learning of three cases of immune effector cell-associated hemophagocytic syndrome, a dangerous disorder in which the body's immune defenses turn against its own organs. Complications from those events led to the deaths, the company said. Novartis added that this type of reaction is a known, potentially life-threatening risk of CAR-T therapy.

The affected trials cover a range of conditions including lupus, rheumatoid arthritis, vasculitis, multiple sclerosis, and myasthenia gravis. Two Novartis trials in patients with lymphoma and leukemia were not affected. Novartis said the eight paused studies had enrolled more than 500 patients, according to the Wall Street Journal .

Bristol Myers said its voluntary pause on trials of zolacabtagene autoleucel, or zola-cel, was made "out of an abundance of caution" to review safety data across its program. A company spokesperson said Bristol Myers had detected inflammatory events during routine surveillance that were temporary and reversible, and that none was fatal. The company said the drug's safety profile remains consistent with other CAR-T therapies.

Novartis said it is conducting a review of the deaths in collaboration with independent safety boards, and that it is sharing information with health authorities. The company has not disclosed whether the three deaths occurred within a single trial or across multiple studies, according to the Wall Street Journal.

The trial freezes were not immediately disclosed to the public. Bristol Myers notified regulators and researchers of its pause back in early June, yet the information stayed out of public view for about three months. Novartis's pause only came to light after William Blair analyst Sami Corwin spotted that a cluster of studies had simultaneously stopped activity while combing through a clinical trials database.

CAR-T therapy involves extracting immune cells from a patient, genetically altering them to seek out and eliminate particular targets, and then returning them to the body. The approach has an established track record in some blood cancers, and companies have more recently turned it toward autoimmune conditions after early studies hinted it might push difficult inflammatory diseases into sustained remissions.

The Novartis news landed the same week the company reported positive results from late-stage trials of remibrutinib , its oral multiple sclerosis drug. Shares climbed 4% on Tuesday, with investors directing their attention to the encouraging remibrutinib readout rather than the trial halt.