Kyverna Therapeutics Announces Positive Topline Data from Registrational KYSA-8 Trial of Miv-cel (KYV-101) in Stiff Person Syndrome

Landmark results could pave the way for miv-cel to become the first FDA-approved CAR T-cell therapy for autoimmune disease; Company on track to submit BLA for stiff person syndrome in 1H 2026 

Miv-cel achieved statistically significant clinical benefit across all primary and secondary endpoints, reversing disability and eliminating immunotherapies after a single dose

Miv-cel was generally well-tolerated with no high-grade CRS or ICANS observed

SPS is a debilitating, progressive autoimmune disease with no FDA-approved therapies

Company to host webcast today, December 15, 2025 at 8 am ET

EMERYVILLE, Calif., Dec. 15, 2025 (GLOBE NEWSWIRE) -- Kyverna Therapeutics, Inc. (Nasdaq: KYTX), a clinical-stage biopharmaceutical company focused on developing cell therapies for patients with autoimmune diseases, today announced positive topline data from KYSA-8, its registrational Phase 2 trial of mivocabtagene autoleucel (‘miv-cel’, formerly KYV-101), a fully human, autologous CD19-targeting CAR T-cell therapy with CD28 co-stimulation, in stiff person syndrome (SPS).

“We are very pleased to share transformative topline data in stiff person syndrome, which could pave the way for miv-cel to become the first and only approved therapy in SPS and CAR T-cell therapy for autoimmune disease,” said Warner Biddle, Chief Executive Officer of Kyverna Therapeutics. “Today’s results further cement our leadership position in the autoimmune CAR T field and add to the growing body of evidence supporting miv-cel’s potential to fundamentally shift the treatment paradigm in autoimmune diseases. We look forward to submitting our BLA for SPS in the first half of 2026 with the goal of bringing this novel therapy to patients and physicians who desperately need an effective treatment for this devastating and progressive disease.”

KYSA-8 Clinical Trial Summary and Topline Data Highlights

KYSA-8 is a single-arm registrational Phase 2 trial in which patients with SPS, who had an inadequate response with non-approved treatment options, received a single dose of miv-cel. A total of 26 patients were dosed and followed through the primary analysis time point (Week 16) with additional follow-up thereafter.

“Today’s topline data represent a significant breakthrough in the treatment of stiff person syndrome, demonstrating miv-cel’s ability to reverse progressive disability in a debilitating disease that has no approved therapies,” said Naji Gehchan, Chief Medical and Development Officer of Kyverna Therapeutics. “With a single dose, miv-cel achieved highly statistically significant and sustained improvements in overall disability, mobility, and stiffness, while enabling all patients to remain free of immunotherapies. In addition, miv-cel demonstrated a well-tolerated and manageable safety profile. We believe these unprecedented results, which support our BLA submission, will have a profound impact on patients. We want to thank the patients, their families and the healthcare providers for participating in this important trial.”