Real-World Toxicity Experience with BRAF/MEK Inhibitors in Patients with Erdheim-Chester Disease

Background Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis. The BRAF inhibitor vemurafenib is approved by the U.S. Food and Drug Administration (FDA) for patients with ECD harboring a BRAF V600E mutation. Successful treatment has also been reported with MEK-targeted therapies, likely because of the fact that BRAF mutant–negative patients harbor MEK pathway alterations. In our Rare Tumor Clinic, we noted that these...