NEW YORK – The US Food and Drug Administration on Friday approved Merck's HIF-2α inhibitor belzutifan (Welireg) for patients with von Hippel-Lindau-associated renal cell carcinoma, pancreatic neuroendocrine tumors, or central nervous system hemangioblastomas.
The approval makes belzutifan an option for patients with any of these tumor types associated with VHL disease — which is marked by a germline VHL mutation — and who do not require immediate surgery. The agent is designed to reduce transcription and expression of HIF-2α target genes, in turn reducing cellular proliferation, angiogenesis, and tumor growth.
The FDA based its decision to approve belzutifan on the results of a Phase II clinical trial, dubbed Study 004, which evaluated the agent in 61 patients with VHL-associated renal cell carcinoma, or RCC. Patients were eligible for the trial if they had additional VHL tumors beyond RCC, too.
The study's objective response rate was 49 percent, and of the patients who responded to belzutifan, 56 percent were experiencing continued responses after one year on the drug. According to a statement from Merck, belzutifan is the first inhibitor therapy approved in the US.