Kyverna Therapeutics has raised the bar in neurologic autoimmune treatment. New data from the company show that one infusion of miv-cel (mivocabtagene autoleucel, KYV-101) can keep patients with stiff person syndrome (SPS) and generalized myasthenia gravis (gMG) in drug-free remission for a year. No approved or experimental therapy has managed this before.
The KYSA-8 study enrolled 26 adults with stiff person syndrome who had not responded adequately to at least one prior immunotherapy, and all participants received a single dose of miv-cel.
For gMG, the Phase 2 KYSA-6 trial followed some patients for up to 1.5 years. Every participant saw real gains in both MG-ADL and QMG scores at 24 weeks. These improvements lasted at least a year for everyone who reached that point. Over half of the patients kept their symptoms to a minimum, and almost all stayed off immunosuppressants at last check. Again, miv-cel’s safety held up, with no severe side effects tied to the therapy.
These results go beyond small steps. For patients with few or no approved options, this could change the landscape. Amanda Piquet, M.D., lead investigator for KYSA-8, put it plainly: “After a single dose of miv-cel, the sustained improvements observed in mobility, stiffness and other disease-specific measures, together with a well-tolerated profile, underscore its potential to deliver significant, long-lasting benefit to patients with SPS.”
Fierce Biotech reported that Kyverna characterized the one-year miv-cel data as a 'resetting conversation' moment for autoimmune CAR-T, especially as other companies in the field have recently faced safety concerns.
Miv-cel stands out for its fully human CD19 CAR T-cell design with CD28 co-stimulation and a strong manufacturing process. Naji Gehchan, M.D., Kyverna’s Chief Medical and Development Officer, says these features help the therapy “reset the immune system, reverse disease progression, and free patients from chronic immunotherapies.”
Most CAR T-cell advances have focused on cancer. Using this approach for neurologic autoimmune diseases is still new. But Kyverna’s results suggest that lasting, drug-free remission is now within reach. This momentum follows other cell therapy breakthroughs, like those recently reported for solid tumors.
An Investing.com market report confirms that miv-cel’s safety in SPS stayed strong through one year, with no high-grade cytokine release syndrome, no ICANS, and no IEC-HS, matching the positive safety seen in both trials.
Kyverna will hold an investor call to go over these results. But the main point is already clear for doctors and biotech watchers. With miv-cel, Kyverna is aiming for more than small gains. If these results hold up in bigger, longer studies, the company could change what’s possible for people with severe neurologic autoimmune diseases. The lasting effect, depth of response, and safety seen with miv-cel set a new standard. Other companies will have to catch up as Kyverna moves toward regulatory review and possible approval.
