Kyverna Therapeutics reported positive registrational results for its patient‑specific CD19 CAR‑T in stiff person syndrome (SPS), showing improvements in mobility and stiffness that met primary and secondary endpoints, the company said. Based on these data, Kyverna plans a U.S. marketing application in the first half of next year. The SPS program targets a rare autoimmune neurologic disorder with no approved cell therapy options; investigators described clinically meaningful functional gains and acceptable safety in the trial population. Kyverna emphasized that pursuing a rare‑disease regulatory path enabled accelerated development and could set a precedent for other CAR‑T autoimmune indications. Regulators will review manufacturing consistency, long‑term safety and durability; reimbursement conversations for an autologous cellular therapy in a rare neurological indication will follow closely if the FDA grants filing acceptance.