FDA

Koselugo now approved for adults with NF1 plexiform nurofibromas

November 27, 2025

On November 19, 2025, FDA approved Koselugo (selumetinib) for adults with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PN). FDA previously approved selumetinib capsules and granules for pediatric patients ≥1 year of age for this indication.

Efficacy

Efficacy was evaluated in the phase 3 KOMET trial (NCT04924608). Eligible patients were required to be ≥18 years of age with NF1 and symptomatic, inoperable PN. Inoperable PN was defined as a PN that could not be completely removed without risk for substantial morbidity due to encasement or close proximity to vital structures, invasiveness, or high vascularity. A total of 145 patients were randomized (1:1) to selumetinib or placebo twice daily for 12 cycles.

The major efficacy outcome measure was confirmed overall response rate (ORR) by the end of cycle 16, determined by independent central review. Duration of response (DOR) was an additional efficacy outcome measure. Confirmed ORR was 20% (95% confidence interval [CI], 11-31) in the selumetinib arm vs. 5% (95% CI, 2-13) for those receiving placebo (p-value, 0.011), with 86% in the selumetinib arm having an observed DOR of at least 6 months.

Safety

Most common adverse reactions in adult patients (≥40%) are rash (all), dermatitis acneiform, and diarrhea.

The prescribing information includes warnings and precautions for left ventricular dysfunction, ocular toxicity, GI toxicity, skin toxicity, increased CPK, increased levels of vitamin E and increased risk of bleeding (Koselugo capsules), and embryo-fetal toxicity.

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 adults with neurofibromatosis type 1 with symptomatic, inoperable plexiform neurofibromas. [News release]. 2025. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-selumetinib-adults-neurofibromatosis-type-1-symptomatic-inoperable-plexiform

Koselugo (selumetinib) [package insert]. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/213756s006lbl.pdf Revised November 2025. Accessed November 26, 2025.