Koselugo shows promise in adults with neurofibromatosis type 1

AstraZeneca (AZ) and Merck, known as MSD outside the US and Canada, have announced encouraging results from a late-stage clinical study of Koselugo (selumetinib) for adults with neurofibromatosis type 1 (NF1). NF1 is a rare genetic disorder that affects approximately 1.7 million people worldwide. The phase 3 KOMET trial focused on evaluating the oral MEK inhibitor in NF1 patients suffering from symptomatic, inoperable plexiform neurofibromas (PNs).

In about half of NF1 patients, tumors develop on the nerve sheaths leading to various complications such as disfigurement, motor and airway dysfunction, pain, visual impairment, and bladder or bowel issues. The KOMET trial achieved its primary endpoint, demonstrating that Koselugo significantly improved the objective response rate compared to a placebo. This was defined by the percentage of patients whose PNs either disappeared or reduced by at least 20% in volume by the 16th treatment cycle.

The safety profile of Koselugo in this study was consistent with previous clinical trials involving children and adolescents, with no new safety issues reported. Koselugo functions by inhibiting the MEK1 and MEK2 enzymes, which play a role in cell growth and are overly active in NF1 cases. While Koselugo is already approved for treating certain pediatric NF1 patients with symptomatic, inoperable PNs, there are no current treatments sanctioned for adult patients.

Marc Dunoyer, CEO of Alexion, AZ’s rare disease unit, expressed optimism over the trial results, noting that Koselugo, as the first and only approved targeted therapy for children with NF1 PN, now shows potential for helping adult patients who currently lack approved targeted therapies. Scot Ebbinghaus, vice president of global clinical development at MSD Research Laboratories, echoed this sentiment, emphasizing the critical need for treatment options for adults with symptomatic, inoperable PNs. He highlighted that the positive phase 3 KOMET trial results suggest the potential for Koselugo to be used in treating adult patients with this rare and complex genetic condition.

With these promising outcomes, the new data on Koselugo will be shared with regulatory bodies and presented at forthcoming medical conferences.