Kyverna Therapeutics released one-year clinical data intended to support an FDA submission for its rare autoimmune CAR-T candidate miv-cel (miv-cel), in stiff person syndrome. The company reported durable autoimmune benefit and framed the dataset as evidence for long-term activity. The announcement arrives as peers in autoimmune CAR-T face heightened scrutiny after safety setbacks, making durability and safety signals particularly consequential for regulators. Kyverna’s messaging centers on sustained efficacy alongside an “unblemished” safety profile for its potential first-in-class program. Editorially, the move underscores how competitive positioning in CGT increasingly turns on the quality of post-treatment durability data, not just initial response. For the CAR-T field, the update also raises expectations for what an FDA review will require for rare autoimmune indications—especially around long-term remission and monitoring duration.