What's Happening?
Kyverna Therapeutics has reported promising results from a pivotal study of its investigational CAR T therapy, mivocabtagene autoleucel (miv-cel), for treating stiff person syndrome (SPS). The therapy demonstrated a 46% median improvement in mobility,
as measured by the timed 25-foot walk (T25FW), and 81% of patients achieved at least a 20% improvement. The study also met all secondary endpoints, including improvements in ambulation, sensitivity, and disability. Importantly, no high-grade cases of cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome were reported. Kyverna plans to file a biologics license application with the FDA in the first half of 2026, potentially making miv-cel the first FDA-approved CAR T therapy for an autoimmune disease.
Why It's Important?
The development of miv-cel represents a significant advancement in the treatment of stiff person syndrome, a rare and debilitating neurological disorder. With fewer than 5,000 affected individuals in the U.S., the condition is characterized by muscle stiffness and painful spasms. Current treatments are limited, and miv-cel offers a potential new option that could reduce or eliminate the need for chronic immunotherapy. The therapy's success could pave the way for further CAR T applications in autoimmune diseases, expanding the scope of this innovative treatment modality beyond oncology.
What's Next?
Kyverna's next steps involve submitting a biologics license application to the FDA, with the aim of securing approval for miv-cel in the treatment of stiff person syndrome. If approved, this could set a precedent for the use of CAR T therapies in autoimmune diseases, potentially leading to further research and development in this area. The biotech industry and patient advocacy groups will likely monitor the FDA's decision closely, as it could influence future therapeutic strategies for rare autoimmune conditions.
