BackgroundThis study provides the first long-term efficacy and safety data of selumetinib in Chinese pediatric patients with inoperable symptomatic plexiform neurofibromas (PN) associated with neurofibromatosis type 1 (NF1).MethodsIn this single-center Phase I clinical trial(NCT04590235), we enrolled children with NF1-related PN aged 3 to <18 years and treated them with selumetinib at a dose of 25 mg/m2 twice daily in 28-day cycles until disease progression or intolerance. The study consisted of