Progressive multifocal leukoencephalopathy in a patient with Hodgkin lymphoma treated with brentuximab vedotin

A 47-year-old human immunodefi ciency virus (HIV)-negative man with relapsed stage IIIB mixed cellularity Hodgkin lymphoma (HL) presented with progressive neurologic defi cits while undergoing treatment with the CD30 directed antibody – drug conjugate, brentuximab vedotin (Adcetris). His prior therapies included eight cycles of ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) in 2004, three cycles of ESHAP (etoposide, solumedrol, cytarabine, cisplatin) in 2007 followed by a BEAM (busulfan, etoposide, cytarabine, melphalan) autologous stem cell transplant, involved fi eld radiotherapy to the neck and mediastinum in 2008, and GVD (gemcitabine, vinorelbine, doxil) in 2009. He relapsed in 2011 and started treatment with brentuximab vedotin 1.8 mg/kg every 3 weeks. Th ree weeks following treatment initiation, the patient complained of impaired coordination and exhibited mild left-greater-than-right dysdiadokinesis. Prior to receiving the third dose of treatment (6 weeks after treatment initiation), the patient reported that his coordination had improved, yet his Eastern Cooperative Oncology Group (ECOG) performance status declined considerably from 0 at baseline evaluation to 3. Th e patient had lost signifi cant