On Aug. 13, 2021, Merck announced that the U.S. Food and Drug Administration (FDA) had approved WELIREG, an oral hypoxia-inducible factor-2 alpha (HIF-2a) inhibitor, for the treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma, central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors, not requiring immediate surgery.

WELIREG was the first HIF-2α inhibitor therapy approved in the U.S. As an inhibitor of HIF-2α, WELIREG reduces transcription and expression of HIF-2α target genes associated with cellular proliferation, angiogenesis and tumor growth.