This study evaluates mirdametinib (PD-0325901) in the treatment of symptomatic inoperable neurofibromatosis type-1 (NF1)-associated plexiform neurofibromas (PNs). All participants will receive mirdametinib (PD-0325901). Eligible participants may continue in a long-term follow-up phase.
A Phase 2b Trial of the MEK 1/2 Inhibitor (MEKi) PD-0325901 in Adult and Pediatric Patients With Neurofibromatosis Type 1 (NF1)-Associated Inoperable Plexiform Neurofibromas (PNs) That Are Causing Significant Morbidity
Neurofibromas are benign peripheral nerve sheath tumors, which are classified as plexiform neurofibromas (PNs) if they extend longitudinally along a nerve and involve multiple fascicles. PNs are a major cause of morbidity and disfigurement in individuals with NF1, and as the tumor growth progresses, can cause a multitude of clinical deficits including pain and impaired physical function. PNs have the potential to undergo malignant transformation to Malignant Peripheral Nerve Sheet Tumors (MPNST).
Mirdametinib (PD-0325901) is an orally delivered, highly selective small-molecule inhibitor of the dual specificity kinases, MEK1 and MEK2 (MAPK/ERK Kinase) which prevents the phosphorylation and subsequent activation of mitogen-activated protein kinase (MAPK).
Previous studies of mirdametinib (PD-0325901) demonstrated PN shrinkage and sustained inhibition of pERK. Reduced tumor volume indicated that cell proliferation or cell death may be altered in PNs with administration of mirdametinib (PD-0325901).