Kyverna Therapeutics reported one-year clinical data supporting its autoimmune CAR-T program miv-cel (miv-cel) in stiff person syndrome, presenting the results as sustained efficacy with no new safety issues. The update lands as peers in autoimmune CAR-T face safety setbacks, and it is positioned by Kyverna as strengthening the FDA submission package. Stiff person syndrome is estimated at around 6,000 patients in the U.S., and Kyverna is framing miv-cel as a potential first-in-class candidate. The reported long-term profile matters most for autoimmune cell therapies where durable benefit must be balanced against immune activation risks. For the field, the data may influence expectations for regulatory review timing and future trial designs in autoimmune CAR-T, where follow-up duration is a central question.