Kyverna Therapeutics’ CAR-T Therapy Delivers Strong Phase 2 Results in Rare Stiff Person Syndrome

Kyverna Therapeutics (NASDAQ:KYTX) reported strong topline results from its registrational Phase 2 KYSA-8 trial evaluating miv-cel (KYV-101) in patients with stiff person syndrome (SPS), marking a significant step forward for the company’s autoimmune-focused CAR-T platform.

In an analysis of 26 dosed patients at Week 16, miv-cel produced a median 46% improvement in the timed 25-foot walk (T25FW) from baseline (p=0.0002).

The majority of treated patients—81%—achieved at least a 20% improvement, exceeding the threshold considered clinically meaningful in SPS mobility assessments.

The therapy delivered highly significant benefit across all secondary endpoints, Kyverna said, noting that each measure met statistical significance with p-values below 0.0001.

SPS, a rare and debilitating neurological disorder, currently lacks curative treatment options, raising expectations for miv-cel’s potential market impact if approved.

Safety outcomes were described as manageable.

No patients experienced high-grade cytokine release syndrome (CRS) or immune effector cell–associated neurotoxicity syndrome (ICANS)—two major risks associated with CAR-T therapies.

Kyverna reported occurrences of Grade 3/4 neutropenia, consistent with expected hematologic toxicities in cell-based treatments.

The company said it plans to submit a Biologics License Application (BLA) in the first half of 2026 and expects to present the full dataset at a medical conference next year.