FDA Accepts for Priority Review Merck’s Supplemental New Drug Application for WELIREG® (belzutifan) in Certain Previously Treated Patients With Advanced Renal Cell Carcinoma (RCC)

Acceptance based on results from the Phase 3 LITESPARK-005 trial, which showed a statistically significant and clinically meaningful improvement in progression-free survival compared to everolimus in patients with advanced RCC that progressed following PD-1/L1 and VEGF-TKI therapies

If approved, WELIREG would provide a new, novel mechanism of action for patients with advanced RCC in need of new options


Reno, Nevada (UroToday.com) -- Merck (NYSE: MRK), known as MSD outside of the United States and Canada, announced the U.S. Food and Drug Administration (FDA) has accepted and granted priority review for a supplemental new drug application (sNDA) seeking approval for WELIREG, Merck’s oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor, for the treatment of adult patients with advanced renal cell carcinoma (RCC) following immune checkpoint and anti-angiogenic therapies. The sNDA is based on data from the LITESPARK-005 trial, in which WELIREG demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to everolimus based on a pre-specified interim analysis conducted by an independent Data Monitoring Committee. A statistically significant improvement in the trial’s key secondary endpoint of objective response rate (ORR) was also demonstrated. The FDA has set a Prescription Drug User Fee Act (PDUFA), or target action, date of January 17, 2024.

“Patients with advanced RCC whose cancer progresses following immune checkpoint and anti-angiogenic therapies face a poorer prognosis, and for those patients, there is a crucial unmet need for new options with an alternative mechanism of action,” said Dr. Marjorie Green, senior vice president and head of late-stage oncology, global clinical development, Merck Research Laboratories. “The FDA’s priority review designation of this application reinforces the urgency to provide new options to previously treated patients with advanced RCC, and we are committed to working closely with the FDA to bring WELIREG to these patients as quickly as possible.”
WELIREG was the first HIF-2α inhibitor therapy approved in the U.S. and is currently approved for the treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated RCC, central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors, not requiring immediate surgery.

LITESPARK-005 is part of a comprehensive development program for WELIREG, comprised of four Phase 3 trials in RCC, including LITESPARK-011 and LITESPARK-012, evaluating WELIREG in the second-line and treatment-naïve advanced disease settings, and LITESPARK-022, evaluating WELIREG in the adjuvant setting.

Source: Merck & Co. (2023). FDA Accepts for Priority Review Merck’s Supplemental New Drug Application for WELIREG® (belzutifan) in Certain Previously Treated Patients With Advanced Renal Cell Carcinoma (RCC) [Press release]. https://www.merck.com/news/fda-accepts-for-priority-review-mercks-supplemental-new-drug-application-for-welireg-belzutifan-in-certain-previously-treated-patients-with-advanced-renal-cell-carcinoma-rcc/.