Novartis and Bristol Myers pause autoimmune CAR-T trials after serious safety events

Novartis and Bristol Myers Squibb announced the suspension of several autoimmune CAR‑T studies after encountering serious safety problems. In Novartis' trials, three participants died from a severe immune reaction, while Bristol Myers reported transient but reversible inflammatory events among participants.

The news triggered an immediate drop in the stock prices of companies involved in autoimmune cell‑therapy development, including Kyverna Therapeutics, Cabaletta Bio, Allogene Therapeutics, CRISPR Therapeutics and Fate Therapeutics, though most recovered later in the day. Analysts say a more cautious approach to manufacturing, patient enrollment and side‑effect management could help avoid future hazards.

Despite the setbacks, other programs remain on track, with Kyverna moving toward an approval decision and several others nearing late‑stage testing. The incidents highlight the challenges of extending CAR‑T technology beyond cancer into autoimmune diseases and may slow broader investment in the field for the near term.