Pembrolizumab treatment for progressive multifocal leukoencephalopathy
Progressive multifocal leukoencephalopathy is an opportunistic brain infection caused by the JC virus, a virus commonly present in kidneys. Immunosuppressed patients with low T cell counts or function are the victims of this viral infection that is usually fatal unless the immune function is restored. Programmed cell death protein 1 found on the surface of T cells suppresses T cells function. The blockage of this protein leads to an increased immune functioning. This report included 8 patients with progressive multifocal leukoencephalopathy who received pembrolizumab at a dose of 2mg/k of body weight, administered every 4 to 6 weeks. No patient received more than 3 doses. Five patients responded with clinical improvement or stabilization and reduction of the JC viral load in the cerebrospinal fluid, and an increase in CD 4 and CD8 cells.
Cortese I, Muranski P, Enose-Akata Y, Seung-Kwon H, Smith B, Monaco MC, et al. Penbrolizumab treatment for progressive multifocal leukoencephalophaty. N Engl J Med. 2019;380:1597-1605. https://doi.org/10.1056/NEJMoa1815039.