From 2 Years to 1: Selumetinib Gains Earlier Access and Granule Formulation

🔔 Update — Approved for ≥1 year (Capsules & Oral Granules)

September 10, 2025: FDA expanded selumetinib (KOSELUGO) to pediatric ≥1y with NF1 and symptomatic, inoperable PN; added oral granules to capsules (prior: ≥2y, capsules only).

• Age expansion: earlier intervention window.
• Granules: toddler-friendly; exposure matched to capsules.
• Bridge: SPRINT (≥2y) ↔ SPRINKLE (≥1y) + adult BA Study 89.
• Safety: incidences updated in a larger pediatric set; no new signals.

💊 New Drugs for a Hereditary Disease

Feb 11, 2025: FDA approved mirdametinib for NF1 + symptomatic, inoperable PN in pediatrics. Alongside selumetinib, it broadens individualized choices (age, adherence needs, co-morbidities, toxicity profile).

• Why it matters: alternative MEK inhibitor with distinct tolerability characteristics.
• Clinical tip: select based on patient goals and AE patterns.

🧬 What Are NF1 and Plexiform Neurofibromas?

NF1 stems from variants in the NF1 tumor-suppressor gene. Plexiform neurofibromas (PN) are benign yet diffuse nerve-sheath tumors causing disfigurement, pain and functional loss; surgery is often high-risk or infeasible.

📜 2020 First Approval

Apr 10, 2020: Selumetinib capsules approved for ≥2y with NF1 + symptomatic, inoperable PN — first targeted therapy for this setting.

🔬 SPRINT Phase 2 Highlights

• n=50 children; selumetinib 25 mg/m² PO BID.
• ORR 66% by volumetric MRI (≥20% reduction maintained ≥3–6 mo).
• Duration: 82% of responses lasted ≥12 months.

🛡️ Safety — Key Precautions

• Cardiomyopathy; ocular toxicity (RVO, RPE detachment); GI & skin toxicities; ↑ CPK.
• KOSELUGO capsules: ↑ vitamin E → bleeding risk. Embryo-fetal toxicity.
• Management: hold, reduce, or discontinue based on severity.

💊 Dosing & Forms

No new safety signals in expanded pediatric dataset.