Selumetinib Approved by FDA for Pediatric Patients With NF1 PN

The kinase inhibitor selumetinib was approved for the treatment of pediatric patients aged 2 years and older with neurofibromatosis type 1 who have symptomatic, inoperable plexiform neurofibromas.

Officials with the FDA have approved the kinase inhibitor selumetinib (Koselugo, AstraZeneca and Merck & Co) for the treatment of pediatric patients aged 2 years and older with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN), the companies announced Monday.1 This is the first FDA-approved medicine for the treatment of NF1 PN in existence, according to AstraZeneca and Merck.1

NF1 is rare and debilitating, with some 30-50% of patients with NF1 experiencing PN, or tumors growing inside their nerve sheaths.1 In patients with PN, clinical issues can emerge such as pain, motor dysfunction, airway dysfunction, bowel and bladder dysfunction, and disfigurement.1

The FDA’s approval was based on the results of the phase 2 SPRINT Stratum 1 trial coordinated by the National Cancer Institute (NCI) Center for Cancer Research, Pediatric Oncology Branch.1

In pediatric patients with NF1 PN, the results of the trial showed an overall response rate (ORR) of 66% for patients when treated with selumetinib as a twice-daily oral monotherapy.1 The ORR in the trial was defined as the percentage of patients with confirmed complete or partial responses of at least 20% reduction in the tumor volume.1

Roy Baynes, Senior Vice President and Head of Global Clinical Development, Chief Medical Officer, Merck Research Laboratories, explained in the press release that this approval provides new hope for patients, changing how symptomatic, inoperable plexiform neurofibromas are treated in the future.1

The most common adverse effects (AEs) to the medicine were reported in equal or less than 40% of patients.1 These AEs included vomiting, rash, abdominal pain, diarrhea, nausea, dry skin, fatigue, musculoskeletal pain, pyrexia, acneiform rash, stomatitis, headache, paronychia, and pruritus.1

In spite of these AEs and other health and safety considerations for the medicine, the positive results of the trial showed that KOSELUGO is ready for use by pediatric patients with NF1 PN.1

“[Selumetinib] has made a difference for many children in this trial. This is an important treatment advance for patients and their families,” said Brigitte C. Widemann, MD, Principal Investigator of the SPRINT clinical trial and Chief, National Cancer Institute (NCI) Pediatric Oncology Branch, in the press release.1


  • FDA approves KOSELUGO™ for pediatric patients with neurofibromatosis type 1 plexiform neurofibromas [news release]. Wilmington, DE: AstraZeneca and Merck & Co., Inc., April 13, 2020. Accessed April 13, 2020.