> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# AstraZeneca/Merck NDA for Neurofibromatosis Drug
- URL: https://www.fdaweb.com/astrazeneca-merck-nda-for-neurofibromatosis-drug/
- Published: 2019-11-14T12:00:00.000Z
- Updated: 2026-09-14T15:53:09.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5145507

FDA has accepted for priority review an AstraZeneca and Merck NDA for MEK 1/2 inhibitor selumetinib for pediatric patients with neurofibromatosis type 1 (NF1) and symptomatic, inoperable plexiform neurofibromas (PNs). The agency is expected to set a second quarter 2020 user fee review action target date, the companies say

The submission is based on positive results from the National Cancer Institute Cancer Therapy Evaluation Program-sponsored SPRINT Phase 2 Stratum 1 trial. “An objective response rate (ORR) was achieved in 66% of pediatric patients with NF1 and symptomatic, inoperable PNs (n=33/50 patients) when treated with selumetinib as a twice-daily oral monotherapy,” the companies say. “ORR was defined as the percentage of patients with a confirmed complete or partial response of greater-than-or-equal- to 20% tumor volume reduction.”

The companies describe selumetinib is an investigational MEK 1/2 inhibitor. It is designed to inhibit the MEK enzyme in the RAS/MAPK pathway, a cell-signaling pathway associated with cancer cell growth and proliferation in a number of different tumor types. NF1 is an incurable genetic condition that affects one in every 3,000 to 4,000 individuals. “It is caused by a spontaneous or inherited mutation in the NF1 gene and is associated with many symptoms, including soft lumps on and under the skin (cutaneous neurofibromas), skin pigmentation (so-called ‘cafe au lait’ spots) and, in 30-50% of patients, tumors develop on the nerve sheaths (plexiform neurofibromas),” they say.