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# FDA Priority Review for New Merck Welireg Indication
- URL: https://www.fdaweb.com/fda-priority-review-for-new-merck-welireg-indication/
- Published: 2025-01-28T12:00:00.000Z
- Updated: 2026-09-14T14:51:50.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5158558

FDA has accepted for priority review a Merck sNDA for a new indication for its Welireg (belzutifan) to treat adults and pediatric patients over age 12 with advanced pheochromocytoma and paraganglioma. A company [statement](https://www.merck.com/news/fda-grants-priority-review-to-mercks-application-for-welireg-belzutifan-for-the-treatment-of-patients-with-advanced-pheochromocytoma-and-paraganglioma-ppgl/?ref=fdaweb.com) says the sNDA was based on objective response rate and duration of response data from the Phase 2 LITESPARK-015 trial. It says FDA set 5/26 as the PDUFA action date for the sNDA.

Welireg is described as the only HIF-2a inhibitor therapy approved in the U.S. to treat adults with von Hippel-Landau disease who require therapy for associated renal cell carcinoma (RCC), central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors not requiring immediate surgery, based on results from the Phase 2 LITESPARK-004 trial. It also is approved to treat adults with advanced RCC following a PD-1/PD-L1 inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor, based on results from the Phase 3 LITESPARK-005 trial.