A clinical phase I study reported significant shrinkage of [[plexiform neurofibroma]]s following treatment with the MEK inhibitor [[selumetinib]]. 

Vaassen et al., reported an 11-year-old [[Neurofibromatosis type 1]] patient with a large [[plexiform neurofibroma]] of the neck that had led to a sharp-angled kinking of the cervical spine and subsequent [[myelopathy]]. Although surgical stabilization of the [[cervical]] [[vertebral column]] was urgently recommended, the vertebral column was inaccessible due to extensive tumor growth. In this situation, treatment with the [[MEK]] inhibitor [[trametinib]] was initiated which resulted in a 22% reduction in tumor volume after 6 months of therapy and finally enabled surgery. These data show that MEK inhibitors may not lead to complete disappearance of NF1-associated plexiform neurofibromas but can be an essential step in a multimodal therapeutic approach for these tumors. The course of this patient suggests that MEK inhibitors are likely to play a significant role in providing a cure for one of the most devastating manifestations of NF1
((Vaassen P, Dürr N, Röhrig A, Willing R, Rosenbaum T. Trametinib Induces
Neurofibroma Shrinkage and Enables Surgery. Neuropediatrics. 2019 May 29. doi:
10.1055/s-0039-1691830. [Epub ahead of print] PubMed PMID: 31141829.
)).