Kyverna soars on trial of miv-cel in stiff person syndrome

US clinical-stage US autoimmune drug developer Kyverna Therapeutics (Nasdaq: KYTX) saw its shares leap more than 23% to $10.82 after its announced positive top-line data from KYSA-8, its registrational Phase II 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 top-line 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 of Kyverna Therapeutics, adding: “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.”

The spasticity treatment market was worth $15.3 billion in 2025, and is predicted to grow to $33.4 billion by 2035, with a CAGR of 8.1%, according to Future Market Insights.