Wheelchair to Walk: Single Infusion Stuns

Patient wearing EEG cap sits while clinician reviews data on tablet — Photo: Shutterstock

A woman who needed a wheelchair for years is now walking on her own again, thanks to a single infusion of engineered immune cells.

Quick Take

A new CAR-T cell therapy called miv-cel is showing major improvement in patients with stiff person syndrome, a rare and disabling autoimmune disorder.
All 26 patients in a Mayo Clinic-led phase two trial saw some symptom improvement after one treatment, with some regaining the ability to walk freely.
The therapy works by wiping out the immune cells that attack the nervous system, essentially resetting the immune system.
Long-term durability is still unknown, since stiff person syndrome research has a history of small studies and short follow-up periods.

A Rare Disease That Steals Mobility Finally Meets a Real Challenger

Stiff person syndrome is a rare autoimmune disease. It causes painful, progressive muscle stiffness and sudden spasms that can knock patients to the ground. Celine Dion’s public battle with the condition brought it into the spotlight. For decades, doctors had no cure, only treatments that dulled symptoms without fixing the underlying problem.

That changed for Lynn Montgomery-Haga, the first United States patient treated with miv-cel in a clinical trial. She had often needed a wheelchair. One year after her single infusion, she was walking freely again. All 26 participants in the trial, run by Kyverna Therapeutics and tested at centers including Mayo Clinic, showed some marked improvement.

Researchers reported the trial’s one-year results showed patients kept their mobility gains, with a third of them completing a 25-foot walk test about as fast as before the disease ever slowed them down. For a condition that often only gets worse over time, holding steady at this level counts as a genuine win for these patients and their families.

How a Cancer Treatment Became a Tool Against a Nerve Disorder

Chimeric antigen receptor T-cell therapy, known as CAR-T, first made headlines as a cancer treatment. Doctors remove a patient’s own T-cells, a type of immune cell, and re-engineer them in a lab. The modified cells then get infused back into the body, programmed to hunt down and destroy specific target cells.

In stiff person syndrome, the target is CD19, a marker found on B-cells, the immune cells believed to drive the attack on the nervous system. Wiping out these B-cells appears to calm the disease at its root, rather than just masking symptoms the way older drugs did. One peer-reviewed case report described a 69-year-old woman with nine years of treatment-resistant disease who improved substantially after a single infusion, with effects tracked for more than six months.

That early case helped launch a larger, phase two study known as KYSA-8, officially testing miv-cel, also called KYV-101, in patients whose disease had resisted every other treatment. Results from that bigger trial, recently published in JAMA Neurology, found early but encouraging evidence that the therapy helped patients regain function they had lost to years of stiffness and spasms.

Why Doctors Are Cautious Even While Celebrating These Results

Stiff person syndrome research has never had the luxury of big, clean studies. A recent review found only 21 case series, 10 cohort studies, and just five randomized trials in the entire field, with long-term follow-up data rarely available. Older treatments like intravenous immunoglobulin sometimes worked for weeks before symptoms crept back as the disease rebuilt its attack.

That history is why doctors call the CAR-T results promising rather than proven. One treated patient regained the ability to walk to her mailbox again, a small task that had been impossible for years, but doctors still do not know how long these gains will last. Patients and families deserve that honesty alongside the hope.

Still, the pattern matters. A disease with no consensus treatment and no large confirmatory trials just produced a therapy that gave wheelchair-bound patients their legs back. Common sense says that is worth taking seriously, even as researchers keep watching for how long the benefit holds and whether it works as well in wider patient groups beyond the initial trial participants.

JAMA Neurology: a nonrandomized registrational trial of single-dose CD19 CAR-T (miv-cel) in stiff person syndrome. At 16 weeks, mobility and disability improved; patients were off chronic immunotherapies. No high-grade CRS or ICANS. Not an approved SPS therapy. #CART #RareDisease…

— ChinaMedPremier (@ChinaMedPremier) November 10, 2026

Mayo Clinic and Kyverna researchers say they are continuing to track patients well beyond the one-year mark. If the mobility gains hold up over several more years, this single-dose therapy could become the first real disease-altering treatment stiff person syndrome patients have ever had, rather than another pill that only buys a little time.