AstraZeneca (AZ) and Merck – known as MSD outside the US and Canada – have shared positive results from a late-stage study of Koselugo (selumetinib) in adults with neurofibromatosis type 1 (NF1), rare genetic condition affecting an estimated 1.7 million people globally.
The phase 3 KOMET trial has been evaluating the oral MEK inhibitor in NF1 patients who have symptomatic, inoperable plexiform neurofibromas (PNs).
In up to 50% of NF1 patients, tumours develop on the nerve sheaths (PNs) and cause clinical issues such as disfigurement, motor dysfunction, pain, airway dysfunction, visual impairment and bladder or bowel dysfunction.
KOMET met its primary endpoint, with Koselugo demonstrating a statistically significant and clinically meaningful improvement in objective response rate versus placebo. This was defined as the percentage of patients whose PNs disappeared or achieved at least a 20% reduction in tumour volume by cycle 16.
The safety profile of Koselugo was also shown to be consistent with that observed in clinical trials among children and adolescents, with no new safety signals identified.
Koselugo is designed to block the MEK1 and MEK2 enzymes, which are involved in stimulating cells to grow and are overactive in NF1.
The drug already holds approvals to treat certain paediatric NF1 patients who have symptomatic, inoperable PNs, but there are currently no approved treatments for adult patients.
Marc Dunoyer, chief executive officer of Alexion, AZ’s rare disease unit, said: “These promising results demonstrate that Koselugo, the first and only approved targeted therapy for certain children with NF1 PN, now has the potential to benefit adult patients for whom there are no approved targeted therapies.”
Scot Ebbinghaus, vice president, global clinical development, MSD Research Laboratories, added: “Adults with NF1 are in critical need of treatment options to help manage symptomatic, inoperable PNs.
“These positive results from the phase 3 KOMET trial demonstrate the potential to expand the use of Koselugo beyond paediatric patients to also treat adult patients living with this rare and challenging genetic condition.”
The new data for Koselugo will now be shared with regulatory authorities and presented at a future medical meeting.