The U.S. FDA just announced that it has accepted Genentech’s supplemental New Drug Application (sNDA) and has granted Priority Review for Zelboraf (vemurafenib) in patients with Erdheim-Chester disease from the BRAF V600 mutation.
Erdhiem-Chester disease, or ECD for short, is a rare histiocytosis disease that is characterized by the absence of Langerhans cells and the abnormal multiplication of a certain type of white blood cell called histiocytes. To learn more about this disease, click here.
ECD is an ultra-rare disease, with less than 500 reported cases in the United States. Because of its rarity, it is all the more difficult to secure adequate treatment funding for patients.
So, for a long time, reports of current treatments indicated little success against ECD, but after an innovative trial that studied Zelboraf in a variety of diseases (but the same genetic mutation), scientists realized that they might have been a breakthrough.
Zelboraf is engineered to inhibit mutations of BRAF, which occurs in over half of all people with ECD. Thus, it made logical sense to test the drug in patients with ECD, alongside of patients with melanoma, who currently have access to ECD.
Twenty-two patients with the disease were tested in a Phase 2, nonrandomized basket study, and the results backed up the researchers’ hypothesis. Only initial results have been published so far, but best overall response rate was an encouraging 54.5%.