Natalizumab treatment for multiple sclerosis: Middle East and North Africa regional recommendations for patient selection and monitoring

Background: Natalizumab, a highly specific alpha 4-integrin antagonist,, has recently been registered across the Middle East and North Africa region. It improves clinical and magnetic resonance imaging (MRI) outcomes and reduces the rate of relapse and disability progression in relapsing-remitting multiple sclerosis (MS). Natalizumab is recommended for patients who fail first-line disease-modifying therapy or who have very active disease. Progressive multifocal leukoencephalopathy is a rare, serious adverse event associated with natalizumab. We aim to develop regional recommendations for the selection and monitoring of MS patients to be treated with natalizumab in order to guide local neurological societies. Methods: After a review of available literature, a group of neurologists with expertise in the management of MS met to discuss the evidence and develop regional recommendations to guide appropriate use of natalizumab in the region. Results: Disease breakthrough is defined as either clinical (relapse or disability progression) or radiological activity (new T2 lesion or gadolinium-enhancing lesions on MRI), or a combination of both. Natalizumab is recommended as an escalation therapy in patients with breakthrough disease based on its established efficacy in Phase III studies. Several factors including prior immunosuppressant therapy, anti-John Cunningham virus (JCV) antibody status and patient choice will affect the selection of natalizumab. In highly active MS, natalizumab is considered as a first-line therapy for naive patients with disabling relapses in association with MRI activity. The anti-JCV antibody test is used to assess anti-JCV antibody status and identify the risk of PML. While seronegative patients should continue treatment with natalizumab, anti-JCV antibody testing every 6 months and annual MRI scans are recommended as part of patient monitoring. In seropositive patients, the expected benefits of natalizumab treatment have to be weighed against the risks of PML. Clinical vigilance and follow-up MRI scans remain the cornerstone of monitoring. After 2 years of natalizumab therapy, monitoring should include more frequent MRI scans (every 3-4 months) for seropositive patients, and the risk-benefit ratio should be reassessed and discussed with patients. Conclusions: Recommendations have been developed to guide neurologists in the Middle East and North Africa on patient selection for natalizumab treatment and monitoring.