Paediatric and adult patients with Neurofibromatosis Type 1 (NF1) and Inoperable Plexiform Neurofibromas (PN) will be evaluated in the screening visit to confirm eligibility. Approximately 16 paediatric and 16 adult qualified patients will receive oral selumetinib 25 mg/m^2 twice a day (approximately every 12 hours) continuously until disease progression or unacceptable drug-related toxicity, whichever occurs first. Once a patient has discontinued the study treatment then the patient will be followed for specified period for safety assessment
A Phase 1 Open Label Study to Assess the Safety, Tolerability, Pharmacokinetics and Clinical Efficacy of Selumetinib, a Selective Mitogen Activated Protein Kinase Kinase (MEK) 1 Inhibitor, in Chinese Paediatric and Adult Subjects with Neurofibromatosis Type 1 (NF1) and Inoperable Plexiform Neurofibromas (PN).