MEK Inhibition with Trametinib in Patients with Non-Langerhans Cell Histiocytosis

Background: Activation of the MAPK pathway through BRAF mutations or other molecular alterations is a hallmark of the non-Lagerhans cell histiocytosis (non-LCH) such Erdheim-Chester disease (ECD) or Rosai-Dorfman disease (RDD). Conventional clinical molecular testing of tumor tissue fails to identify targetable molecular alteration in about one third of patients with non-LCH. Targeting the MAPK kinase pathway in non-LCH with small molecule...