In the largest study of its kind, a virus-specific T cell therapy achieved a response in more than half of treated patients with a rare and often deadly neurological condition caused by viral infection, according to Phase 2 study results. The investigational, off-the-shelf virus-specific T cells achieved an overall response rate of 56.8% in 37 patients with progressive multifocal leukoencephalopathy (PML), including 43.2% achieving complete viral clearance with stabilization or improvement of neurological symptoms. Patients responded quickly – typically within 23 days – and the one-year overall survival rate for all treated patients was 61.1%. Patients who responded after their first infusion experienced a one-year survival rate of 93.3%.
“For decades, physicians have had no approved treatment to offer patients with PML, and this disease has long represented one of the greatest unmet needs in neuroinfectious medicine,” said corresponding author Katy Rezvani, M.D., Ph.D., vice president and head of the Institute for Cell Therapy Discovery & Innovation, and professor of Stem Cell Transplantation and Cellular Therapy, whose team developed the virus-specific T cell platform. “Seeing rapid viral clearance and meaningful clinical responses in more than half of treated patients is extremely encouraging as we try to identify a potential standard treatment.”