Kyverna Shares Surge on Positive One-Year Data for Autoimmune Therapy

Shares of Kyverna Therapeutics (NASDAQ:KYTX) surged nearly 10% in early trading Thursday after the biotechnology company announced positive one-year durability data from trials of its CAR T-cell therapy, mivocabtagene autoleucel (miv-cel), in two rare autoimmune neurological disorders.

The company reported that the sustained clinical benefits observed support the potential for miv-cel to become a first-in-class approved therapy for stiff person syndrome (SPS) and the first approved CAR T-cell therapy for any autoimmune disease.

Key Trial Results

Kyverna released updated data from two separate clinical trials, highlighting the therapy's sustained efficacy at the one-year mark and beyond.

Stiff Person Syndrome (KYSA-8 Trial)

In its registrational trial for SPS, follow-up data on 26 patients at 12 months showed:

• A significant improvement in the timed 25-Foot Walk test was sustained at the one-year mark.
• 95% of patients who had achieved a clinically meaningful improvement at the primary analysis sustained that benefit.
• 92% of patients remained free of chronic immunotherapies for the condition.

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Generalized Myasthenia Gravis (KYSA-6 Trial)

In the Phase 2 trial for gMG, follow-up data extending up to 1.5 years demonstrated strong results:

• All seven patients achieved clinically meaningful improvement in disease measures by 24 weeks.
• These improvements were maintained through one year or longer in all five patients who have reached that time point.
• 57% of patients maintained minimal symptom expression.

Safety Profile and Regulatory Path

Across both trials, miv-cel continued to show a well-tolerated safety profile. Kyverna reported no instances of high-grade cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS), which are known potential side effects of CAR T-cell therapies.

The company confirmed its rolling Biologics License Application (BLA) submission to the FDA remains on track for completion in the fourth quarter of 2026. Meanwhile, enrollment for the Phase 3 portion of the gMG trial is expected to be completed in mid-2027. Kyverna plans to present the full SPS data set at the joint ACTRIMS-ECTRIMS meeting in October 2026.