Efficacy and Safety of Selumetinib in Adults With NF1 Who Have Symptomatic, Inoperable Plexiform Neurofibromas

Key Inclusion Criteria:

• Adults ≥ 18 years at enrollment with diagnosis of NF1 with symptomatic, inoperablePN

• At least one inoperable target PN measurable by volumetric MRI analysis

• Chronic target PN pain score documented for minimum period during screening period

• Stable chronic PN pain medication use at enrollment

• Adequate organ and marrow function

Key Exclusion Criteria:

• Confirmed or suspected malignant glioma or MPNST (low grade glioma, including opticglioma not requiring systemic therapy or radiation therapy are exempt from thisexclusion)

• History of malignancy except for malignancy treated with curative intent with noknown active disease ≥ 5 years before the first dose of study intervention and oflow potential risk for recurrence

• Clinically significant cardiovascular disease, including inherited coronary disease,acute coronary syndrome within 6 months prior to enrollment, uncontrolled angina,symptomatic heart failure, cardiomyopathy, severe valvular heart disease, abnormalLVEF and uncontrolled hypertension

• Ophthalmological findings/conditions including intraocular pressure > 21 mmHg,RPED/CSR or RVO

• Prior exposure to MEK inhibitors