Progressive Multifocal Leukoencephalopathy Associated with Ruxolitinib

Abstract
Ruxolitinib, an inhibitor of Janus kinases (JAKs) 1 and 2, has been approved in the United States and Europe for the treatment of myelofibrosis.1 We report a case of progressive multifocal leukoencephalopathy (PML) in a patient with myelofibrosis after initiation of ruxolitinib therapy.