KYTX · Kyverna Therapeutics, Inc.

Kyverna Therapeutics reported compelling longer-term data from the Phase 2 portion of its KYSA-6 registrational trial for miv-cel in generalized myasthenia gravis (gMG). The update, presented at the AAN Annual Meeting, showed 100% of patients achieving rapid and sustained improvements in MG-ADL and QMG scores at 24 weeks, with mean reductions of -8.5 and -11.3 points, respectively. Critically, these deep responses were sustained out to 52 weeks in the three patients with available follow-up, and 57% of patients achieved minimal symptom expression (MSE) at last follow-up. These efficacy signals are particularly strong given the patient population had moderate-to-severe gMG and had failed prior immunosuppressant therapies, including FcRns and complement inhibitors.

The safety profile remains a key differentiator, with no high-grade CRS or ICANS events observed. Only two patients experienced transient grade 3/4 neutropenia related to lymphodepletion, which fully resolved. This tolerability supports the potential for outpatient administration, a significant advantage in the CAR T landscape. Furthermore, 100% of patients remained free of nonsteroidal immunosuppressants, high-dose steroids, and FcRn/complement inhibitors through Week 24, suggesting miv-cel's ability to enable drug-free remission. Biomarker data indicated robust CAR T-cell expansion, deep B-cell depletion, and evidence of immune reset. With the Phase 3 portion of KYSA-6 currently enrolling across 14 sites, these data substantially de-risk the registrational path and reinforce management's confidence in miv-cel's potential best-in-class profile for autoimmune indications.