FDA grants RMAT designation for stiff person syndrome therapy

The FDA has granted Regenerative Medicine Advanced Therapy designation to a Bay Area-based biopharmaceutical company for its autologous, fully human CD19 chimeric antigen receptor to treat those with refractory stiff person syndrome.

According to a press release from Kyverna Therapeutics Inc., KYV-101 is a CAR T-cell product candidate to treat B cell-driven autoimmune diseases, designed by the NIH to improve tolerability and previously tested in a 20-patient phase 1 trial in oncology.

The novel therapeutic is being tested in two ongoing clinical trials — sponsored, open-label, phase 1/2 and phase 2 studies conducted in the United States and Germany — for potential applications in rheumatology and neurology.

“The data generated from all our ongoing trials will improve our understanding how KYV-101 can represent a paradigm shift in patients' treatment without relying on long-term immunosuppressive therapies,” Kyverna CEO Peter Maag, PhD, told Healio in an email.

A rare, progressive autoimmune disorder, stiff person syndrome presents with debilitating muscle stiffness in the torso, arms and legs, impacting an individual’s motor functionality. Patients typically present with muscle spasms and stiffness, resulting in difficulty turning and bending, per the release.

In December 2022, singer Celine Dion was diagnosed with the rare condition.

According to the release, symptoms such as muscle spasms and stiffness can be precipitated by unexpected stimuli including loud, piercing sounds such as a phone ring or siren, sudden touches or conditions triggering anxiety and emotional upset which. When severe, the symptoms can be misdiagnosed as an anxiety disorder.