Natalizumab use in pediatric multiple sclerosis.

BACKGROUND Natalizumab, a humanized monoclonal antibody raised against alpha4 integrins, is approved for treatment of active relapsing-remitting multiple sclerosis (RRMS) in adult patients. OBJECTIVE To determine the safety, effectiveness, and tolerability of natalizumab use in pediatric patients with MS. DESIGN Case report. SETTING Center for MS in childhood and adolescents, Göttingen, Germany. PATIENTS Three pediatric patients with RRMS having a poor response to other immunomodulatory therapies or having intolerable adverse effects. INTERVENTIONS Natalizumab given every 4 weeks at a dosage of 3 to 5 mg/kg of body weight. MAIN OUTCOME MEASURES Cranial magnetic resonance (MR) imaging before treatment and every 6 months thereafter. RESULTS During 24, 16, and 15 months of treatment, no further relapses occurred in the 3 pediatric patients; all reported significant improvement in their quality of life. Follow-up MR imaging showed no new T2-weighted lesions or gadolinium-enhancing lesions. No adverse events were seen when dosage was adjusted to body weight. CONCLUSIONS Natalizumab treatment was effective and well tolerated in our pediatric patients with RRMS who did not respond to initial immunomodulatory treatments. Therefore, it is a promising second-line therapy for pediatric patients with RRMS.