The mouse models were developed for preclinical testing carried out in the Ratner and Wu groups. MEK inhibition significantly shrunk more than 70 percent of plexiform neurofibromas – the nerve tumors caused by NF1. The data were so compelling that the team reported the study provided “strong rationale” for testing the drug in a clinical trial.

In February, 2018 the MEK inhibitor Selumetinib was granted Orphan Drug Designation by the US FDA for neurofibromatosis type 1. This FDA program provides orphan status to medicines that are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US.