The designation has been provided based on Phase II data from the Sprint trial, which evaluated selumetinib as an oral monotherapy in pediatric patients aged three years or older with inoperable NF1-related PN.
The Sprint trial is a US Cancer Therapy Evaluation Program (CTEP) NCI-sponsored Phase I/II trial designed to identify the optimal Phase II dosing regimen.
The NF1 gene provides guidance for making a protein known as neurofibromin, which negatively regulates the RAS/MAPK pathway to control cell growth, differentiation and survival.
AstraZeneca oncology research and development executive vice president José Baselga said: “Selumetinib shows promise in the treatment of NF1-related plexiform neurofibromas, a rare and debilitating disease with no approved medications to date.
“The Breakthrough Therapy Designation acknowledges the significant unmet need of these patients and the potential benefit of selumetinib in this setting.”
Selumetinib is said to be a MEK 1/2 inhibitor and potential new medicine licensed by AstraZeneca from Array BioPharma in 2003.
Selumetinib secured orphan drug designation from the FDA to treat NF1 in February 2018. The European Medicines Agency also granted the same designation in August 2018.
The ongoing trials are evaluating selumetinib as a monotherapy and in combination with other treatments.
In July 2017, AstraZeneca and Merck have collaborated to co-develop and co-commercialize Lynparza (olaparib) and selumetinib to treat multiple cancer types.
According to AstraZeneca, NF1 is an incurable genetic condition that affects one in 3,000 to 4,000 individuals and it is caused by a spontaneous or inherited mutation in the NF1 gene and is associated with multiple symptoms.
MSD Research Laboratories chief medical officer, global clinical development head and senior vice president Roy Baynes said: “This new designation validates our ongoing development of selumetinib. As a result of this, selumetinib has the potential to receive expedited regulatory review and we hope to bring this medicine to patients as soon as possible.”