Kyverna Therapeutics disclosed 1-year follow-up data for miv-cel in stiff person syndrome, aiming to strengthen its FDA submission in the rare autoimmune CAR-T space. The company said the updated results support sustained efficacy while maintaining what it described as an unblemished safety profile. The update lands as multiple autoimmune CAR-T programs face scrutiny over emerging safety signals, raising the value of longer follow-up datasets for regulators and payers evaluating risk-benefit assumptions in neuroimmune indications. Kyverna’s positioning is centered on durability—an outcome regulators often weigh heavily for one-time cellular therapies—alongside the effort to de-risk toxicities with additional time on study.