Stiff Person Syndrome: One-Off CAR-T Drug Eases Symptoms in Trial
A one-off immunotherapy given in a US clinical trial restored lost everyday function in two patients with stiff person syndrome, the rare condition Celine Dion has. Mayo Clinic researchers say larger trials could follow, but it is unclear if the gains will last.
A new drug eases syndrome suffered by singer Celine Dion: a one-off CAR-T cell therapy restored lost everyday function in two patients with stiff person syndrome (SPS) in a US clinical trial, according to results published in Jama Neurology.
The trial was led by Mayo Clinic in Rochester in the US. Researchers say the results could now lead to larger studies.
SPS is a rare neurological disorder that gets progressively worse. Symptoms include stiffness in the body, spine, arms and legs.
How the treatment works
Chimeric antigen receptor T-cell (CAR-T) therapy teaches the body's immune system to recognize and attack cells that cause disease. It is already approved on the NHS for some illnesses, including certain types of cancer.
Patients in the trial received it as a single dose.
Two patients' recoveries
Jonathan Walden had reached the point where walking and basic daily tasks needed help from his family. After treatment he has returned to work and normal activities.
"I can go to work every single day. I can do everything I did before. I go hunting, I can go fishing," he said. "I have not had one episode since receiving treatment."
Shari St Germain was diagnosed in 2021. She had severe leg cramps and trouble walking, and sudden noises caused muscle rigidity and falls. By 2024, standard treatments no longer controlled her symptoms.
In the months after CAR-T therapy she noticed improvements. One day she walked on a treadmill again. "I just walked for seven minutes on the treadmill," she said. "So every day, it just gets better and better."
What researchers say
Dr Anastasia Zekeridou, a neurologist and researcher at Mayo Clinic, said the degree of improvement in some patients was the most striking finding. "With existing treatments, we may be able to improve symptoms, but we very rarely see patients return to their previous level of function," she said.
She called the early results "very encouraging". The key question, she said, is whether the improvements will be sustained over time.
Dr Sean Pittock, chairman of the department of neurology at Mayo Clinic, said CAR-T therapy has already transformed the treatment of some cancers. He said the results offer "tremendous hope" for people with SPS and potentially for patients with other immune-mediated neurologic conditions.
About the condition
SPS affects an estimated 8,000 people worldwide. The British Neurological Surveillance Unit identified 119 confirmed cases in the UK across a five-year tracking period between 2000 and 2005.
It is thought to be an autoimmune condition, in which the immune system attacks healthy cells by mistake. It affects twice as many women as men.
Dion, the Canadian singer, announced in December 2022 that she had been diagnosed. In an Instagram video she said the condition had affected "every aspect of my daily life", including harming her voice.
