FDA

Koselugo now approved for NF1 plexiform neurofibromas in younger patients

September 15, 2025

FDA approved Koselugo (selumetinib) granules and capsules for pediatric patients ≥1 year of age with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN).

The drug was previously approved for pediatric patients ≥2 year of age.

Efficacy

Approval was based on adequate bridging between the oral granule and approved capsule formulations in a relative bioavailability (BA) study in healthy adults (Study 89) and exposure matching between the pediatric patient populations in the SPRINT Phase II Stratum I study (capsule formulation, ≥2 years of age) and the SPRINKLE study (oral granule formulation, ≥1 year of age). Similar exposure between the formulations supports extrapolation of efficacy from pediatric patients ≥2 years of age to ≥1 year of age.

Safety

The selumetinib prescribing information includes warnings and precautions for cardiomyopathy, ocular toxicity, GI toxicity, skin toxicity, increased CPK, increased levels of vitamin E and increased bleeding risk (Koselugo capsules), and embryo-fetal toxicity. The incidences of warnings and precautions were updated to include data from a larger number of pediatric patients; no new safety signals were identified.

Recommended dose

The recommended dosage of selumetinib, based on body surface area, is 25 mg/m² orally twice daily, until disease progression or unacceptable toxicity.

Sources:

FDA approves selumetinib for pediatric patients 1 year of age and older with neurofibromatosis type 1 with symptomatic, inoperable plexiform neurofibromas [News release] 2025. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-selumetinib-pediatric-patients-1-year-age-and-older-neurofibromatosis-type-1

Koselugo (sulemetinib) [package insert]. AstraZeneca. https://alexion.us/-/media/alexion_global/documents/regulatory/north-america/usa/2025/koselugo_uspi.pdf. Revised September 2025. Accessed September 12, 2025.