FDA Grants Priority Review for New Drug Application for HIF-2α Inhibitor Belzutifan (MK-6482)

Application Based on Objective Response Rate From Phase 2 Trial Evaluating Belzutifan in Patients With Von Hippel-Lindau Disease-Associated Renal Cell Carcinoma

New Filing Further Strengthens Merck’s Expanding and Diverse Oncology Portfolio

San Francisco, CA (UroToday.com) -- Merck, known as MSD outside the United States and Canada, announced that the U.S. Food and Drug Administration (FDA) has accepted and granted priority review for a New Drug Application (NDA) for the hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor belzutifan (pronounced bell-ZOO-ti-fan), a novel investigational candidate in Merck’s oncology pipeline, for the potential treatment of patients with von Hippel-Lindau (VHL) disease-associated renal cell carcinoma (RCC), not requiring immediate surgery. This NDA is based on data from the Phase 2 Study-004 trial, in which belzutifan showed a confirmed overall response rate of 36.1% (n=22/61) (95% CI: 24.2-49.4) in patients with VHL disease-associated RCC. The FDA has set a Prescription Drug User Fee Act (PDUFA), or target action, date of September 15, 2021.


“Von Hippel-Lindau disease is a rare genetic condition for which there is no systemic treatment option available and is associated with a high risk of cancer development in multiple organs. In fact, up to 70% of patients with VHL develop renal cell carcinoma during their lifetime,” said Dr. Scot Ebbinghaus, vice president, clinical research, Merck Research Laboratories. “This priority review validates the important progress we have made to expand and diversify Merck’s oncology pipeline with innovative, new therapeutic approaches. We look forward to working closely with the FDA to bring belzutifan to patients in need.”

Merck is also studying belzutifan in advanced RCC and other tumor types through a broad clinical program. In addition to the ongoing Phase 2 Study-004 trialbelzutifan is being evaluated in Phase 3 trials as monotherapy and as part of a combination regimen in previously treated patients and as part of a combination regimen as a first-line treatment for advanced clear cell RCC.

About the Phase 2 Study-004 Trial

This application is based on data from Study-004 (NCT03401788), which is a Phase 2, open-label trial evaluating belzutifan for the potential treatment of patients with VHL disease who had at least one measurable solid tumor localized to the kidney and who did not require immediate surgery. The study enrolled 61 patients who received belzutifan 120 mg orally once daily until disease progression or unacceptable toxicity. The primary endpoint was objective response rate in VHL disease-associated RCC. Secondary endpoints in RCC tumors include disease control rate, duration of response, time to response, progression-free survival, time to surgery, and safety.

Additionally, this study evaluated response rates in other common VHL disease-associated tumors, including pancreatic cysts, pancreatic neuroendocrine tumors, central nervous system (CNS) hemangioblastomas, and retinal hemangioblastomas.

Source: Merck.com. 2021. Merck Receives Priority Review From FDA for New Drug Application for HIF-2α Inhibitor Belzutifan (MK-6482) - Merck.com.