EMERYVILLE, Calif., Nov. 9, 2026 – Kyverna Therapeutics, Inc. (Nasdaq: KYTX), a late-stage clinical immunology company developing transformative therapies for neurological autoimmune diseases, today announced the publication of primary analysis results from its KYSA-8 registrational trial evaluating miv-cel (mivocabtagene autoleucel, KYV-101) in patients with stiff person syndrome (SPS) in JAMA Neurology.
The findings were previously presented during a late-breaking oral session at the American Academy of Neurology (AAN) Annual Meeting in April 2026. Kyverna recently also presented one-year durability data from KYSA-8 at the MS Toronto meeting, jointly organized by ACTRIMS and ECTRIMS.
In KYSA-8, a single administration of miv-cel demonstrated statistically significant improvements across all primary and secondary endpoints at Week 16. All patients discontinued chronic immunotherapies following treatment. Among the 12 patients who required walking assistance at baseline, 67% no longer required walking assistance at Week 16. Miv-cel also demonstrated a consistent and well-tolerated safety profile.
“The publication of the KYSA-8 registrational data in JAMA Neurology underscores the unique potential of miv-cel to liberate patients with stiff person syndrome from life-long disease burden and chronic immunotherapy use,” said Marinos C. Dalakas, MD, PhD, Professor of Neurology at Thomas Jefferson University, senior author and lead study investigator. “Importantly, for patients and the field, miv-cel showed a well-tolerated safety profile with no high-grade CRS or ICANS, and no cases of IEC-HS. Having cared for patients with SPS for more than 30 years and witnessed the debilitating impact of this progressive disease, I believe miv-cel can change the therapeutic landscape for SPS by offering the potential to reverse patient disability. It’s truly remarkable to see some of my patients who, for years, required assistive devices to now walking independently, in some cases even running.”
Warner Biddle, Chief Executive Officer of Kyverna Therapeutics, added: “The publication of our registrational KYSA-8 trial data in JAMA Neurology marks an important milestone for both the miv-cel SPS program and Kyverna. These unprecedented results demonstrate clinical outcomes not previously seen in SPS, including patients regaining mobility after a single dose of miv-cel. The data further support miv-cel’s potential to redefine treatment in SPS by reversing the course of this debilitating and progressive disease while maintaining a well-tolerated safety profile. With no approved therapies for SPS and a significant unmet need, we are working urgently to bring miv-cel to patients as quickly as possible. We believe these findings further support the potential of miv-cel across a range of neurological autoimmune diseases.”
The full study, titled “Mivocabtagene Autoleucel CD19 Chimeric Antigen Receptor T-Cell Therapy in Stiff Person Syndrome: A Nonrandomized Clinical Trial,” was published in the November 9 issue of JAMA Neurology.
About the KYSA-8 Registrational Clinical Trial
KYSA-8 is a single-arm registrational Phase 2 clinical trial evaluating miv-cel in 26 adults with stiff person syndrome who had an inadequate response to at least one immunotherapy treatment. Participants received a single dose of miv-cel.
The primary endpoints include change from baseline in the Timed 25-Foot Walk (T25FW) at Week 16 and the incidence and severity of adverse events. Secondary endpoints assess disability, stiffness, hypersensitivity, and mobility using the Modified Rankin Scale (mRS), Distribution-of-Stiffness Index (DSI), Heightened Sensitivity Scale (HSS), and Hauser Ambulation Index (HAI), respectively.
About Miv-cel (Mivocabtagene Autoleucel, KYV-101)
Miv-cel is a fully human, autologous CD19-targeting CAR T-cell therapy incorporating CD28 co-stimulation. The therapy is designed to achieve deep B-cell depletion and potentially reset the immune system, with the goal of delivering durable, drug-free and disease-free remission following a single administration.
Miv-cel is being investigated for B-cell-driven autoimmune diseases and is manufactured using an established and validated manufacturing process. More than 100 patients have received miv-cel across multiple autoimmune diseases to date, with clinical data demonstrating a consistent and well-tolerated safety profile.
About Stiff Person Syndrome (SPS)
Stiff person syndrome is a rare, progressive neurological autoimmune disease characterized by muscle stiffness and painful spasms that can significantly affect mobility and walking ability. Stiffness, rigidity, and spasms involving the torso, arms, and legs can lead to progressive disability. Up to 80% of patients may lose mobility and require walking assistance or wheelchair use. SPS has also been associated with permanent disability and an increased risk of mortality.
Most patients with SPS have antibodies against glutamic acid decarboxylase 65 (GAD65) or the glycine receptor. These antibodies interfere with normal inhibitory neurotransmission and contribute to the characteristic symptoms of the disease.
Currently, no FDA-approved treatments are available for SPS. Treatment options include symptomatic medications, off-label immunotherapies such as intravenous immunoglobulin (IVIg), rituximab and plasmapheresis, along with supportive care and physical, speech, occupational, and psychiatric therapies. However, many patients experience inadequate or no response to available treatment approaches. An estimated 6,000 patients have been diagnosed with SPS in the United States.
About Kyverna Therapeutics
Kyverna Therapeutics, Inc. (Nasdaq: KYTX) is a late-stage clinical immunology company developing differentiated therapies with curative potential for neurological autoimmune diseases. Its lead autologous CD19-targeting CAR T-cell therapy candidate, miv-cel (mivocabtagene autoleucel, KYV-101), has demonstrated potential to change treatment approaches across multiple B-cell-driven autoimmune diseases.
Kyverna is advancing its neuroimmunology pipeline following completion of its registrational trial in stiff person syndrome and continues to evaluate miv-cel in an ongoing registrational trial for generalized myasthenia gravis (gMG).
Miv-cel has received three FDA Regenerative Medicine Advanced Therapy (RMAT) designations for SPS, gMG, and non-active secondary progressive multiple sclerosis (naSPMS), based on clinical data supporting its potential in neurological autoimmune diseases. Kyverna continues to develop additional innovations intended to expand treatment access and patient choice.
For more information, visit kyvernatx.com.
Forward-Looking Statements
This press release contains forward-looking statements regarding Kyverna’s future expectations, plans, and prospects, as well as statements concerning matters that are not historical facts. Such statements may be identified by terms including “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” and similar expressions, although not all forward-looking statements contain these terms.
Forward-looking statements include, but are not limited to, statements concerning the potential transformative and durable clinical benefits of a single dose of miv-cel; its potential to reverse the course of SPS, redefine treatment, and maintain a well-tolerated safety profile; Kyverna’s regulatory pathway and the potential for FDA approval of miv-cel for SPS; efforts to bring miv-cel to patients as quickly as possible; the potential for miv-cel to become the first approved therapy for SPS and the first approved CAR T-cell therapy for autoimmune disease; its potential to reduce lifelong disease burden and chronic immunotherapy use, reverse disability, and change the treatment landscape for SPS; its potential to deliver durable, drug-free, disease-free remission across autoimmune diseases; potential benefits associated with FDA RMAT designations for SPS, gMG, and naSPMS; and anticipated pipeline milestones involving SPS, gMG, PMS, and other development opportunities.
Actual results may differ materially from those expressed or implied in these forward-looking statements due to various risks and uncertainties, including market conditions; the possibility that results from previous clinical trials, named-patient access activities, or preclinical studies may not predict future outcomes; the possibility that the FDA or other regulatory authorities may require additional studies, delay approval, or decline to approve miv-cel; intellectual property risks; and other factors described under “Risk Factors” in Kyverna’s Annual Report on Form 10-K for the year ended December 31, 2025, and Quarterly Report on Form 10-Q for the quarter ended June 30, 2026.
All forward-looking statements are based on Kyverna management’s current expectations and speak only as of the date of this release. Kyverna disclaims any obligation to update such statements, whether as a result of new information, future events, or otherwise.
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