Koselugo Gains EU Approval Following Strong Phase III Results In Adult Neurofibromatosis Type 1

Alexion, AstraZeneca Rare Disease, has received approval from the European Union (EU) for Koselugo (selumetinib)—a selective MEK inhibitor—for the treatment of symptomatic, inoperable plexiform neurofibromas (PN) in adult patients with neurofibromatosis type 1 (NF1). This marks an important expansion of Koselugo’s indication beyond paediatric use, offering a much-needed treatment option for adults affected by this rare genetic disorder.

Prof. Pierre Wolkenstein, MD, PhD, Head of the Department of Dermatology at Henri Mondor Hospital, APHP, Paris East University (UPEC), and National Coordinating Investigator of the KOMET trial in Europe, said: “The approval of Koselugo for adults with NF1 PN in Europe offers patients and physicians a meaningful approach to close treatment gaps beyond childhood. As demonstrated in the KOMET Phase III trial, the most robust late-stage clinical trial conducted in this patient group to-date, adults administered Koselugo saw significant tumour volume reduction with a safety profile consistent with its established use in paediatric patients, validating the clinical benefits of Koselugo for newly diagnosed adults and those transitioning to adult care.”

The European Commission’s approval follows a positive recommendation from the Committee for Medicinal Products for Human Use (CHMP) and is backed by results from KOMET, the largest and only placebo-controlled Phase III global trial in this patient group. Findings from the trial—presented at the 2025 ASCO Annual Meeting and published in The Lancet—showed Koselugo achieved a 20% objective response rate (ORR) compared to 5% with placebo, demonstrating a significant clinical benefit. The safety profile was consistent with its established use in paediatric populations.

Marc Dunoyer, Chief Executive Officer, Alexion, said: “The European Commission approval extends the life-changing potential of Koselugo to adults with NF1 PN in the region, including continuity of care into adulthood. This milestone, along with our pioneering leadership in NF1 PN treatment landscape, embodies Alexion’s unwavering commitment to addressing the unmet needs in the rare disease community. We look forward to bringing Koselugo to those adults in need across Europe as soon as possible.”

Neurofibromatosis type 1 (NF1) is a rare genetic condition typically diagnosed in childhood but often progressing into adulthood, affecting multiple organ systems. Up to half of those with NF1 develop plexiform neurofibromas—benign tumours that can cause severe pain, disfigurement, and nerve dysfunction. With recent approvals in Japan and other countries, and ongoing regulatory reviews globally, Koselugo continues to strengthen its position as a vital therapy for managing NF1-related plexiform neurofibromas in adults.