Comment je gère un traitement par natalizumab au-delà de la 24e cure

Natalizumab is a highly efficacious disease-modifying drug for patients with active relapsing multiple sclerosis (MS). However it is associated with an increased risk of progressive multifocal leucoencephalopathy (PML). Three risk factors for developing this opportunistic infection have been identified: presence of anti-JC virus antibodies, prior use of immunosuppressants, and duration of natalizumab treatment beyond 24 months. Thus, the continuation of the natalizumab must be systematically reevaluated with the patient after 24 months of treatment. The decision is largely based on the anti-JCV antibody status which, if it is positive, leads in most cases to stop the treatment. Other factors such as the severity of the disease and the anti-JCV antibody index can influence the decision. If natalizumab is continued beyond 24 months, informed consent by the patient and close monitoring are required. If natalizumab is stopped, a number of questions arise: choice of the therapeutic alternative, duration of the wash-out, monitoring procedure. These important issues will be discussed here according to the data of the literature.