Natalizumab therapy for highly active pediatric multiple sclerosis.

Importance: Given the high frequency of failure of first-line therapies, there is an urgent need for second-line treatment strategies for pediatric patients with multiple sclerosis (MS).

Objective: To report the use of natalizumab in pediatric MS. Natalizumab, a humanized monoclonal antibody targeting α4 integrin, is effective against active relapsing-remitting MS in adults.