Use of natalizumab in persons with multiple sclerosis: 2022 update

Background: Natalizumab is a humanized monoclonal antibody used for treatment of highly active relapsingremitting multiple sclerosis (MS). With more than 15 years of post-marketing experience with natalizumab in Canada, several real-world studies have shown the long-term efficacy and safety of natalizumab. In addition, risk stratification/mitigation strategies for progressive leukoencephalopathy (PML), an adverse effect associated with natalizumab based on the John Cunningham virus (JCV) index; treatment duration beyond 24 months; and prior exposure to immunosuppressant drugs have been developed.Methods: A group of neurologists from various MS clinics across Canada met in September 2021 to update the 2015 Canadian practice recommendations for the use of natalizumab in persons with MS (PwMS).Results: The recommendations focused on the long-term efficacy and safety data from real-world studies, patient selection according to JCV index criteria, risk management strategies for PML (including extended interval dosing), and options for switching to currently available disease-modifying therapies for MS.Conclusions: The recommendations of clinical neurologists seek to optimize the management of PwMS who may benefit from treatment with natalizumab.