Alexion wins EU label expansion for kinase inhibitor Koselugo

The European Commission (EC’s) has approved Alexion (AstraZeneca’s Rare Disease arm)’s oral MEK inhibitor for adults with the rare genetic condition neurofibromatosis type 1 (NF1).

Koselugo (selumetinib) is indicated for patients with symptomatic, inoperable plexiform neurofibroma tumours, which occurs in up to 50 percent of cases.

The EC’s approval is based on results from the phase III KOMET clinical trial, the largest and only placebo-controlled global phase III trial in this patient population. Study data was presented at the 2025 American Society of Clinical Oncology (ASCO) congress.

Dr Pierre Wolkenstein, PhD, Professor, National Coordinating Investigator of the KOMET trial in Europe, said: “Adults administered Koselugo saw significant tumour volume reduction with a safety profile consistent with its established use in paediatric patients.”

While the Commission conditionally approved the treatment for paediatric patients in 2021, this new approval means eligible adults can now benefit too.

Primary analysis of the trial showed that Koselugo provided a statistically significant objective response rate (ORR) of 20 percent compared to five percent with placebo by cycle 16.

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.”

AstraZeneca and MSD agreed in July 2017 to co-develop and co-commercialise Koselugo as well as the PARP inhibitor Lynparza (olaparib).

As well as the EU, Koselugo is approved for eligible adults in Japan, and for certain paediatric patients in the US, Japan and China. There are ongoing additional regulatory reviews for approval in other regions.