Welireg (Belzutifan) for Kidney Cancer

Overview
Welireg is approved by the U.S. Food and Drug Administration (FDA) for the treatment of adults with advanced renal cell carcinoma (RCC) with a clear cell component. To be eligible, a person must have previously been treated with a programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI). It’s also approved for the treatment of adults with von Hippel-Lindau (VHL) disease who require therapy for associated RCC, central nervous system (CNS) hemangioblastomas, or pancreatic neuroendocrine tumors (pNET) and do not require immediate surgery. Welireg is also known by its drug name, belzutifan.

Welireg is a hypoxia-inducible factor (HIF) inhibitor. It works by blocking a protein that tumors use to grow in low-oxygen environments, which can help slow or stop the growth of kidney cancer cells.

How do I take it?
Prescribing information states that Welireg is taken orally once daily, with or without food. The drug should be taken exactly as prescribed by a health care provider.

Side effects
Common side effects of Welireg include decreased hemoglobin (a protein in red blood cells), fatigue, musculoskeletal pain, increased creatinine (a waste product measured to assess kidney function), decreased lymphocytes (a type of white blood cell), increased alanine aminotransferase and aspartate aminotransferase (liver enzymes), decreased sodium, and increased potassium.

In people with VHL disease, additional common side effects include headache, dizziness, increased glucose, and nausea.

Rare but serious side effects may include severe anemia (low red blood cell count), life-threatening hypoxia (low oxygen levels in the blood), and reproductive toxicity that can impair fertility in males and females. Welireg may also cause harm to a fetus if used during pregnancy. A person should confirm they are not pregnant before starting the drug and use effective nonhormonal contraception during treatment, as Welireg can reduce the effectiveness of hormonal birth control.

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Label: Welireg — Belzutifan Tablet, Film Coated — DailyMed