FDA Approves First-Ever Treatment for Rare Blood Cancer

The U.S. Food and Drug Administration (FDA) expanded the approval of vemurafenib, a kinase inhibitor, to include the treatment of adult patients with BRAF-V600-mutated Erdheim-Chester disease (ECD). This is the first FDA-approved treatment for ECD.

“Today’s approval of [vemurafenib] for patients with ECD demonstrates how we can apply knowledge of the underlying genetic characteristics of certain malignancies to other cancers,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a statement. “This product was first approved in 2011 to treat certain patients with melanoma that harbor the BRAF V600E mutation, and we are now bringing the therapy to patients with a rare cancer with no approved therapies.”

The efficacy of vemurafenib for the treatment of ECD was studied in 22 patients with BRAF-V600-mutated ECD. The trial measured the percent of patients who experienced a complete or partial reduction in tumor size (overall response rate). In the trial, 11 patients (50%) experienced a partial response and 1 patient (4.5%) experienced a complete response.

Common side effects of vemurafenib in patients with ECD included arthralgia, rash, hair loss, fatigue, prolonged QT interval, and skin growths. Severe side effects included development of new cancers, tumor growth in patients with BRAF wild-type melanoma, hypersensitivity reactions, severe skin reactions, cardiac abnormalities, liver damage, photosensitivity, severe eye reactions, radiation sensitivity, kidney failure, and thickening of tissue in the hands and feet.

Source: FDA news release, November 6, 2017.