FDA Expands Selumetinib to Children With NF1-Associated Plexiform Neurofibromas

The FDA has approved an expanded indication of selumetinib (Koselugo; AstraZeneca) for pediatric patients aged 1 year and older with neurofibromatosis type 1 (NF1) who have symptomatic, inoperable plexiform neurofibromas (PNs), expanding access to younger children who previously fell below the age threshold of the original authorization.¹

This action builds on the agency’s 2020 approval of selumetinib for pediatric patients aged 2 years and older with NF1 and symptomatic, inoperable PNs, which established the drug as the first targeted therapy for this indication.² Together, these decisions reflect the significant morbidity associated with NF1-PNs, including pain, disfigurement, and functional compromise—and the need for disease-directed options early in the disease course.^1,2

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The original approval of selumetinib was largely due to clinical results that showed significant and lasting tumor shrinkage, as well as symptom relief, in children with NF1-PNs, grounding selumetinib’s first clinical use.² Now, the indication is widened to include patients aged 1 year and older based mainly on a regulatory bridging approach, which involved the comparison of a new oral granule formulation (for young children who cannot swallow capsules) and the approved capsule formulation by pharmacokinetics, followed by matching of pediatric exposures.¹

Central to this new formulation is the SPRINKLE study (NCT05309668), which evaluated the pharmacokinetics, safety, tolerability, and exploratory efficacy of selumetinib granules in children aged 1 to 7 years with symptomatic, inoperable PNs, enabling dosing recommendations and extrapolation to the younger age group.⁴ In combination with prior efficacy experience that underpinned the 2020 decision, these data supported the expanded age indication.^1-3

For pediatric patients with NF1-PNs, selumetinib is given based on their body surface area, twice a day by mouth, and discontinued at either the time of disease progression or when the toxicity becomes unacceptable, which is the same dosing regimen for both the capsule and granule formulations.¹ The granule’s release gives a feasible way for precise dosing and better acceptability for young children and toddlers who cannot take capsules; thus, adherence may be improved, and the start of treatment could be facilitated when PN-related symptoms emerge.^1,3 Pharmacists can help caregivers interpret body surface area calculations, align the measured dose with available strengths, and reinforce administration techniques that maintain dosing accuracy over time.

Based on FDA communications, careful attention is recommended for cardiac and ocular toxicities, as well as gastrointestinal and dermatologic adverse events that require structured monitoring and prompt management to lessen the number of interruptions in treatment.¹ The enlarged pediatric dataset has not signaled any new safety issues; however, it indicates the necessity of baseline and periodic assessments that are appropriate to local practice standards.¹

Furthermore, laboratory parameters should be kept under clinical observation to decide on dose holds or reductions in cases of adverse events, which should be done in a manner that balances the continuation of antitumor benefit with patient tolerability.² Pharmacists can operationalize these safeguards by coordinating baseline workups, scheduling follow-up evaluations, and educating families on early symptom recognition and reporting.

REFERENCES

1. FDA approves selumetinib for pediatric patients 1 year of age and older. U.S. Food and Drug Administration. Published 2025. Accessed September 10, 2025. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-selumetinib-pediatric-patients-1-year-age-and-older-neurofibromatosis-type-1

2. FDA approves selumetinib for neurofibromatosis type 1 with symptomatic, inoperable plexiform neurofibromas. FDA. Published online April 13, 2020. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-selumetinib-neurofibromatosis-type-1-symptomatic-inoperable-plexiform-neurofibromas

3. Clinicaltrials.gov. Published 2025. Accessed September 10, 2025. https://www.clinicaltrials.gov/study/NCT05309668