Kyverna Therapeutics Inc. (NASDAQ: KYTX) reported one-year clinical data for miv-cel, a fully human autologous CD19-targeting CAR T-cell therapy, across two ongoing studies targeting autoimmune conditions.
In the KYSA-8 trial evaluating miv-cel in stiff person syndrome, 26 patients demonstrated sustained improvements in mobility measures at 12 months. The median improvement in the timed 25-foot walk was 49% from baseline, according to the data presented by Emeryville, California-based Kyverna. Ninety-five percent of patients who achieved clinically meaningful improvement at the primary analysis maintained that benefit through the one-year mark, and 92% remained free of chronic immunotherapies for the condition. No high-grade cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome was observed through one year of follow-up, and no cases of immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome were reported.
Stiff person syndrome is a rare progressive neurologic autoimmune disease with an estimated 6,000 diagnosed patients in the United States. No FDA-approved treatments currently exist for the condition.
In the Phase 2 portion of the KYSA-6 trial for generalized myasthenia gravis, all seven patients achieved clinically meaningful improvement in disease activity measures at 24 weeks. Five of those patients who reached one year or longer of follow-up continued to maintain their improvements. As of their last follow-up, 86% of patients had discontinued immunosuppressants. The Phase 3 portion of the KYSA-6 trial remains ongoing, with enrollment expected to be completed in mid-2027.
Kyverna stated that more than 100 patients have been treated with miv-cel across various autoimmune diseases to date. The company's rolling Biologics License Application submission for miv-cel in stiff person syndrome remains on track for completion in the fourth quarter of 2026.
