Randomized trial of vigabatrin in patients with infantile spasms

Abstract

Infantile spasms are a rare but devastating pediatric epilepsy that, outside the United States, is often treated with vigabatrin. The authors evaluated the efficacy and safety of vigabatrin in children with recent-onset infantile spasms. This 2-week, randomized, single-masked, multicenter study with a 3- year, open-label, dose-ranging follow-up study included patients who were younger than 2 years of age, had a diagnosed duration of infantile spasms of no more than 3 months, and had not previously been treated with adrenocorticotropic hormone, prednisone, or valproic acid. Patients were randomly assigned to receive low-dose (18-36 mg/kg/day) or high-dose (100-148 mg/kg/day) vigabatrin. Treatment responders were those who were free of infantile spasm for 7 consecutive days beginning within the first 14 days of vigabatrin therapy. Time to response to therapy was evaluated during the first 3 months, and safety was evaluated for the entire study period. Overall, 32 of 142 patients who were able to be evaluated for efficacy were treatment responders (8/75 receiving low-dose vigabatrin vs 24/67 receiving high doses, p < 0.001). Response increased dramatically after approximately 2 weeks of vigabatrin therapy and continued to increase over the 3-month follow-up period. Time to response was shorter in those receiving high-dose versus low-dose vigabatrin (p = 0.04) and in those with tuberous sclerosis versus other etiologies (p < 0.001). Vigabatrin was well tolerated and safe; only nine patients discontinued therapy because of adverse events. These results confirm previous reports of the efficacy and safety of vigabatrin in patients with infantile spasms, particularly among those with spasms secondary to tuberous sclerosis.