Pembrolizumab Treatment for Progressive Multifocal Leukoencephalopathy

Abstract
Progressive multifocal leukoencephalopathy (PML) is an opportunistic brain infection that is caused by the JC virus and is typically fatal unless immune function can be restored. Programmed cell death protein 1 (PD-1) is a negative regulator of the immune response that may contribute to impaired viral clearance. Whether PD-1 blockade with pembrolizumab could reinvigorate anti–JC virus immune activity in patients with PML was unknown.
Funding Information
  • Intramural Research Program, NIH