Progressive multifocal leukoencephalopathy with natalizumab extended or standard interval dosing in the United States and the rest of the world.

Background: Progressive multifocal leukoencephalopathy (PML), an important identified risk for natalizumab, has been described for standard interval dosing (SID; dosing interval every-4-weeks). Information on PML with natalizumab extended interval dosing (EID; dosing interval >every-4-weeks) in the US and the rest of the world (ROW) is limited.

Research Design And Methods: A retrospective analysis of patient demographics, risk factors, clinical characteristics, and clinical outcomes was conducted on confirmed natalizumab EID and SID PML cases evaluated from Biogen pharmacovigilance systems.

Progressive multifocal leukoencephalopathy outcomes in patients with multiple sclerosis treated with dimethyl fumarate.

Background And Objectives: Dimethyl fumarate (DMF), an oral disease-modifying therapy with an established benefit and well-described safety profile, is among the most commonly used therapies for relapsing forms of multiple sclerosis. As of 31 December 2021, >560,000 patients have been treated with DMF, representing >1,190,000 person-years of exposure. Of these, 6413 patients (14,292 person-years) were from clinical trials.