Selumetinib for paediatric patients with NF1 PN

AstraZeneca and MSD announced that the US FDA has approved selumetinib (Koselugo) for the treatment of paediatric patients two years of age and older with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN).

The approval by the FDA was based on positive results from the National Cancer Institute (NCI) Cancer Therapy Evaluation Program (CTEP)-sponsored phase II SPRINT Stratum 1 trial coordinated by the NCI’s Center for Cancer Research, Paediatric Oncology Branch. 

This is the first regulatory approval anywhere in the world of a medicine for the treatment of NF1 PN.

Results showed an overall response rate (ORR) of 66% (33 of 50 patients, confirmed partial response) in paediatric patients with NF1 PN when treated with selumetinib as a twice-daily oral monotherapy. ORR is defined as the percentage of patients with confirmed complete or partial response of at least 20% reduction in tumour volume.

Selumetinib is inhibitor of mitogen-activated protein kinase kinases 1 and 2 (MEK1/2). MEK1/2 proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway. Both MEK and ERK are critical components of the RAS-regulated RAF-MEK-ERK pathway, which is often activated in different types of cancers.