Kyverna Therapeutics (NASDAQ:KYTX) Chief Executive Warner Biddle said the company is advancing toward a potential first launch of its lead CAR-T therapy, miv-cel, in autoimmune disease, with its initial focus on Stiff Person Syndrome, during a fireside chat hosted by H.C. Wainwright senior biotech analyst Mitchell Kapoor.
Biddle said Kyverna has begun a rolling biologics license application submission for miv-cel in Stiff Person Syndrome and remains on track to complete the filing in the fourth quarter of this year. He described miv-cel as the company’s lead construct, designed specifically for autoimmune diseases with a focus on potency and improved safety.
Stiff Person Syndrome Filing Remains Central Focus
He framed the results against the natural history of Stiff Person Syndrome, saying patients generally do not spontaneously improve and that more than 80% eventually progress into increasing disability. He also said only 19% of patients are still working four years after initial diagnosis.
According to Biddle, two-thirds of KYSA-8 patients who needed walking aids when entering the study were able to remove those aids after 16 weeks. He said the company is also seeing reductions in background therapies, with patients going off immunosuppressants and other chronic treatments as part of treatment with miv-cel.
Biddle said Kyverna held a pre-BLA meeting with the U.S. Food and Drug Administration and has alignment on the “core components” of the filing, including the single-arm study design, the primary endpoint, the chemistry, manufacturing and controls package, the safety package and the preclinical package. He said the FDA has asked for additional analyses of natural history data to contextualize KYSA-8, and Kyverna is working to provide those analyses.
Durability and Payer Discussions
Kapoor asked about the company’s expected one-year follow-up data for Stiff Person Syndrome, which Biddle said will be provided in the second half of the year. Biddle said all patients in the study reached the 16-week primary endpoint, and 16 patients have reached the 24-week milestone. He also said the first patients treated through compassionate use programs are now two years or more from dosing and remain off background immunosuppressants and chronic IVIG.
Biddle said Kyverna has been engaging with payers ahead of a possible launch. He said payer feedback has been “remarkably positive” after reviewing pivotal data presented at the American Academy of Neurology meeting. He cited the high cost of IVIG, which he said can reach hundreds of thousands of dollars per year for patients receiving monthly or biweekly treatment, as part of the value discussion around a one-time therapy.
Commercial Launch Preparation
Kyverna is targeting an initial launch through roughly 10 academic centers, though Biddle said that number could change slightly. He said the company believes Stiff Person Syndrome patients are concentrated in a limited number of centers and treated by a relatively small group of physicians, allowing for an efficient commercial buildout.
Biddle said Kyverna is working on site onboarding, cell orchestration systems, patient support systems, payer access planning and manufacturing forecasts. He said the company has identified an immediately addressable refractory Stiff Person Syndrome population of about 2,000 to 2,500 patients who have failed IVIG or existing therapies.
When asked about launch hurdles, Biddle said Kyverna’s physician research found that 90% of Stiff Person Syndrome treaters viewed the miv-cel profile as highly compelling, and 85% said they would use it in moderate to severe Stiff Person Syndrome patients at launch. He said lymphodepletion has not impeded trial recruitment, though the company is evaluating alternative regimens, including bendamustine and no lymphodepletion.
Manufacturing and Pipeline Updates
Biddle said Kyverna is working with ElevateBio in Boston and Minaris Advanced Therapies in Philadelphia for manufacturing. He said the company has publicly reported a 98% manufacturing success rate overall and had a 100% manufacturing success rate in its Stiff Person Syndrome trial.
Beyond Stiff Person Syndrome, Biddle highlighted myasthenia gravis as the next major indication. He said data from the KYSA-6 phase 2 study showed reductions of 8.5 points in MG-ADL scores and 11.3 points in QMG scores. Kyverna has started a phase 3 head-to-head study comparing miv-cel with standard of care, with superiority being assessed on MG-ADL and QMG. Biddle said recruitment is going well and the study is active at 15 centers globally, including U.S. sites.
Biddle also discussed progressive multiple sclerosis, citing early investigator-initiated work led by Jeffrey Dunn at Stanford University. He said Kyverna has observed stabilization of EDSS and, in a majority of patients, improvement in EDSS and fatigue scores after a single dose of miv-cel. He said those results will inform how the company prioritizes progressive MS as a potential future indication.
Looking ahead, Biddle said Kyverna expects several updates in the second half of the year, including one-year Stiff Person Syndrome follow-up data, progress on phase 3 enrollment and maturing data in myasthenia gravis, additional progressive MS data and phase 2 rheumatoid arthritis data.
About Kyverna Therapeutics (NASDAQ:KYTX)
Kyverna Therapeutics is a clinical?stage biotechnology company dedicated to developing engineered regulatory T?cell (Treg) therapies for the treatment of autoimmune and inflammatory diseases. Leveraging a proprietary platform for the isolation, expansion and modification of Treg cells, the company aims to restore immune homeostasis in patients by delivering antigen?specific cell therapies that selectively target diseased tissues while minimizing systemic immunosuppression.
The company’s lead programs include an allogeneic Treg candidate in clinical development for ulcerative colitis, with additional preclinical assets focused on rheumatoid arthritis and other chronic inflammatory conditions.
