OBJECTIVE: To describe the effect of natalizumab in the treatment of subjects
with active multiple sclerosis (MS) treated before the age of 18 years.
METHODS: Nineteen pediatric subjects with MS (mean age 14.6 +/- 2.2 years, mean
number of attacks 5.2 +/- 1.9 during the pretreatment phase of 27.7 +/- 19.7
months, median pretreatment Expanded Disability Status Scale score [EDSS] 2.5,
range 1.0-5.0) were treated with natalizumab at the dose of 300 mg every 28 days.
After treatment initiation, patients were reassessed clinically every month;
brain MRI was performed at baseline and every 6 months.
RESULTS: Patients received a median number of 15 infusions (range 6-26). A
transient reversible worsening of preexisting symptoms occurred in 1 subject
during and following the first infusion. All the patients remained relapse-free
during the whole follow-up. The median EDSS decreased from 2.5 to 2.0 at the last
visit (p < 0.001). EDSS remained stable in 5 cases, decreased by at least 0.5
point in 6 cases, and decreased by at least 1 point in 8 cases. At baseline, the
mean number of gadolinium-enhancing lesions was 4.1 (range 1-20). During the
follow-up, no gadolinium-enhancing lesions were detected (p = 0.008); 3 patients
developed new T2-visible lesions at month 6 scan but the overall number of T2
lesions remained stable during the subsequent follow-up. Transient and mild side
effects occurred in 8 patients.
CONCLUSIONS: Natalizumab was well-tolerated in all subjects. A strong suppression
of disease activity was observed in all subjects during the follow-up.
Classification of evidence: This study provides Class IV evidence that
natalizumab, 300 mg IV once every 28 days, decreased EDSS scores in pediatric
patients with MS over a mean treatment period of 15.2 months
