Langerhans Cell Histiocytosis With MAP2K1E102_I103del Mutation Successfully Treated With Trametinib

Abstract

The discovery of the MAPK pathway mutations in lesions of patients with Langerhans cell histiocytosis (LCH) has made targeted therapy an important therapeutic approach for these patients. Theoretically, the RAF-independent mutation MAP2K1^E102_I103del is naturally resistant to allosteric MEK inhibitors. We report a dramatic response to MEK inhibitor trametinib in a case of LCH with MAP2K1^E102_I103del mutation, which indicates that trametinib is worth trying in recurrence and refractory LCH patients with MAP2K1^E102_I103del.

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