Long-term efficacy and safety of lamotrigine monotherapy in Japanese and South Korean pediatric patients with newly diagnosed typical absence seizures: An open-label extension study

Abstract Purpose To investigate the efficacy and safety of long-term lamotrigine (LTG) monotherapy in Japanese and South Korean pediatric patients with newly diagnosed typical absence seizures. Methods Six Japanese patients and one South Korean patient were enrolled in the extension phase of the study after completing the 12-week maintenance phase of an open-label clinical study of LTG monotherapy. During the extension phase, patients underwent efficacy and safety evaluation every 12 weeks. Results Of the seven patients, six patients completed the extension phase. The seizure-free rate confirmed by hyperventilation (HV)-electroencephalography ranged from 71.4% to 100.0% at each visit up to Week 168 of the extension phase. Similar effects were confirmed by HV-clinical signs and seizure diaries. Although no unexpected adverse events were observed, one Japanese patient was withdrawn from the extension phase due to mild drug-related rash developed 842 days after the start of LTG. Conclusion Although the number of patients is limited, long-term LTG monotherapy appeared to be effective and generally well tolerated in Japanese and South Korean pediatric patients with typical absence seizures.