Kyverna’s Miv-cel Achieves 46% Mobility Boost, 100% Immunotherapy Cessation
Kyverna’s Phase 2 KYSA-8 trial of miv-cel in stiff person syndrome patients showed a median 46% improvement in 25-foot walk time at Week 16 (p=0.0003), with 81% achieving meaningful gains and all discontinuing chronic immunotherapies. The company plans a BLA submission based on safety and efficacy over a 6.5-month follow-up.
1. Registrational Trial Results
Kyverna conducted the single-arm Phase 2 KYSA-8 registrational trial of miv-cel in stiff person syndrome patients unresponsive to off-label immunomodulators, assessing change from baseline in Timed 25-Foot Walk at 16 weeks and adverse event incidence.
2. Efficacy Outcomes
The trial met its primary endpoint with a median 46% improvement in T25FW at Week 16 (p=0.0003), 81% of patients achieved ≥20% improvement, 33% walked at healthy adult speeds, 67% of those needing aids no longer required assistance, and all discontinued chronic immunotherapies through a 6.5-month median follow-up.
3. Safety Profile
Miv-cel was well tolerated with no high-grade cytokine release syndrome or neurotoxicity, manageable grade 3/4 neutropenia in four patients, and three serious treatment-related adverse events that resolved fully without sequelae.
4. Regulatory and Next Steps
The company is preparing a BLA submission for SPS based on these results and is evaluating miv-cel’s potential in myasthenia gravis and other neurologic autoimmune diseases with a single-dose, deep immune reset approach.