Efficacy of BRAF-Inhibitor Therapy in BRAFV600E -Mutated Adult Langerhans Cell Histiocytosis.

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplasm. To date, there is a lack of U.S. Food and Drug Administration-approved treatments in adult LCH to establish optimal first-line therapy. We conducted a retrospective, single-center case series evaluating the use of BRAF inhibitors in adult patients with BRAFV600E - LCH proven by biopsy. Our case series is the first to report the use of BRAF inhibitors as first-line therapy in adults with LCH. We also report the efficacy with single-agent dabrafenib in adult LCH. All but one of our patients had favorable response to targeted therapy.