Belzutifan
/api/v1/drug/belzutifanBoxed warning
EMBRYO-FETAL TOXICITY Exposure to WELIREG during pregnancy can cause embryo-fetal harm. Verify pregnancy status prior to the initiation of WELIREG. Advise patients of these risks and the need for effective non-hormonal contraception. WELIREG can render some hormonal contraceptives ineffective [see Warnings and Precautions (5.3) , Drug Interactions (7.2) , Use in Specific Populations (8.1 , 8.3) ]. WARNING: EMBRYO-FETAL TOXICITY See full prescribing information for complete boxed warning. Exposure to WELIREG during pregnancy can cause embryo-fetal harm. Verify pregnancy status prior to the initiation of WELIREG. Advise patients of these risks and the need for effective non-hormonal contraception. WELIREG can render some hormonal contraceptives ineffective. ( 5.3 , 7.2 , 8.1 , 8.3 )
Mechanism of action
Sourced from openFDABelzutifan is an inhibitor of hypoxia-inducible factor 2 alpha (HIF-2α). HIF-2α is a transcription factor that plays a role in oxygen sensing by regulating genes that promote adaptation to hypoxia.
Indications
Sourced from openFDA- WELIREG is a hypoxia-inducible factor inhibitor indicated: von Hippel-Lindau (VHL) disease for treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system (CNS) hemangioblastomas, or pancreatic neuroendocrine tumors (pNET), not requiring immediate surgery. ( 1.1 ) Advanced Renal Cell Carcinoma (RCC) for treatment of adult patients with advanced renal cell carcinoma (RCC) with a clear cell component following 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).
Contraindications
Sourced from openFDA- None. None.contraindicated
Dosage & administration
Sourced from openFDAThe recommended dosage of WELIREG in adult patients is 120 mg administered orally once daily with or without food. ( 2.1 ) The recommended dosage of WELIREG in pediatric patients 12 years and older is based on bodyweight: Patients weighing ≥ 40 kg: 120 mg orally once daily Patients weighing < 40 kg: 80 mg orally once daily 2.1 Recommended Dosage The recommended dosage of WELIREG in adult patients is 120 mg administered orally once daily. The recommended dosage of WELIREG in pediatric patients 12 years and older is based on bodyweight: Patients weighing ≥ 40 kg: 120 mg orally once daily Patients weighing < 40 kg: 80 mg orally once daily Continue WELIREG until disease progression or unacceptable toxicity. WELIREG should be taken at the same time each day and may be taken with or without food. Advise patients to swallow tablets whole. Do not chew, crush, or split WELIREG prior to swallowing. If a dose of WELIREG is missed, it can be taken as soon as possible on the same day. Resume the regular daily dose schedule for WELIREG the next day. Do not take extra tablets to make up for the missed dose. If vomiting occurs any time after taking WELIREG, do not retake the dose. Take the next dose on the next day. 2.2 Dosage Modifications for Adverse Reactions Dosage modifications for WELIREG for adverse reactions are summarized in Table 1 .
Warnings & precautions
Sourced from openFDAAnemia : Monitor for anemia before initiation of and periodically throughout treatment with WELIREG. Withhold WELIREG until hemoglobin ≥8g/dL, then resume at the same or reduced dose or discontinue. For life threatening anemia, or for anemia requiring urgent intervention, withhold WELIREG until hemoglobin ≥8g/dL and resume at a reduced dose or permanently discontinue WELIREG. ( 2.2 , 5.1 ) Hypoxia : Monitor oxygen saturation before initiation of, and periodically throughout, treatment with WELIREG. For hypoxia at rest, withhold until resolved, resume at reduced dose, or discontinue depending on severity. For life-threatening hypoxia, permanently discontinue WELIREG. ( 2.2 , 5.2 ) 5.1 Anemia WELIREG can cause severe anemia that can require blood transfusion. Monitor for anemia before initiation of, and periodically throughout, treatment with WELIREG. Transfuse patients as clinically indicated. For patients with hemoglobin <8g/dL, withhold WELIREG until ≥8g/dL, then resume at the same or reduced dose or permanently discontinue WELIREG, depending on the severity of anemia. For life threatening anemia or when urgent intervention is indicated, withhold WELIREG until hemoglobin ≥8g/dL, then resume at a reduced dose or permanently discontinue WELIREG [see Dosage and Administration (2.2) ] . von Hippel-Lindau (VHL) disease In LITESPARK-004, decreased hemoglobin occurred in 93% of patients and 7% had Grade 3 events [see Adverse Reactions (6.1) ] . Median time to onset of anemia was 31 days (range: 1 day to 8.4 months).
Adverse reactions
Sourced from openFDAThe following clinically significant adverse reactions are discussed elsewhere in the labeling: Anemia [see Warnings and Precautions (5.1) ] Hypoxia [see Warnings and Precautions (5.2) ] VHL disease : Most common (≥25%) adverse reactions, including laboratory abnormalities, were decreased hemoglobin, fatigue, increased creatinine, headache, dizziness, increased glucose, and nausea. ( 6.1 ) Advanced RCC : Most common (≥25%) adverse reactions, including laboratory abnormalities were decreased hemoglobin, fatigue, musculoskeletal pain, increased creatinine, decreased lymphocytes, increased alanine aminotransferase, decreased sodium, increased potassium, and increased aspartate aminotransferase. ( 6.1 ) PPGL : Most common (≥25%) adverse reactions, including laboratory abnormalities were anemia, fatigue, musculoskeletal pain, decreased lymphocytes, increased alanine aminotransferase, increased aspartate aminotransferase, increased calcium, dyspnea, increased potassium, decreased leukocytes, headache, increased alkaline phosphatase, dizziness, and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Use in specific populations
Sourced from openFDALactation : Advise not to breastfeed. ( 8.2 ) Infertility : May impair fertility in males and females. ( 8.3 ) 8.1 Pregnancy Risk Summary Based on findings in animal studies, WELIREG can cause fetal harm when administered to a pregnant woman. There are no available data on the use of WELIREG in pregnant women to inform the drug-associated risk. In an animal reproduction study, oral administration of belzutifan to pregnant rats during the period of organogenesis caused embryo-fetal lethality, reduced fetal body weight, and fetal skeletal malformations at maternal exposures ≥0.2 times the human exposure (AUC) at the recommended dose of 120 mg daily ( see Data ). Advise pregnant women and females of reproductive potential of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively. Data Animal Data In a pilot embryo-fetal development study, pregnant rats received oral doses of 6, 60, or 200 mg/kg/day of belzutifan during the period of organogenesis. Belzutifan caused embryo-fetal lethality at doses ≥60 mg/kg/day (approximately 1 time the human exposure at the recommended dose based on AUC).
Pharmacokinetics
Sourced from openFDA- Metabolism
- The C max and AUC of belzutifan increase proportionally over a dose range of 20 mg to 120 mg (0.17 to 1 times the approved recommended dose). The estimated geometric mean steady-state (CV%) C max is 1.5 μg/mL (45%) and AUC 0-24h is 20 μg•hr/mL (62%) .
Overdosage
Sourced from openFDAThere is no specific treatment for WELIREG overdose. In cases of suspected overdose, withhold WELIREG and institute supportive care. Grade 3 hypoxia occurred at dosages of 120 mg twice a day and Grade 4 thrombocytopenia occurred at dosages of 240 mg once daily (approximately 2 times the recommended dosage).
Approval history
Sourced from openFDA- Aug 13, 2021NDANDA215383Merck Sharp Dohme
FAERS reports
- 1Anaemia22217%
- 2Malignant Neoplasm Progression13410.0%
- 3Hypoxia1239.2%
- 4Fatigue1128.3%
- 5Death614.5%
- 6Dyspnoea614.5%
- 7Diarrhoea584.3%
- 8Haemoglobin Decreased523.9%
- 9Off Label Use523.9%
- 10Nausea403.0%
- 11Oxygen Saturation Decreased403.0%
- 12Therapy Interrupted372.8%
- 13Product Dose Omission Issue322.4%
- 14Dizziness292.2%
- 15Drug Ineffective292.2%
Clinical trials
The 10 most recently updated of 42 ClinicalTrials.gov registrations naming Belzutifan as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- Phase II Trial of Single Agent Belzutifan or Pembrolizumab Versus Combination as Neoadjuvant Therapy in Clear Cell Renal Cell Carcinoma (BLAZE)Recruiting · Phase 2 · Interventional · 10 enrolled · M.D. Anderson Cancer CenterNCT07187778updated 2026-06-12
- A Clinical Study of Belzutifan and Zanzalintinib in People With Recurrent Kidney Cancer Following Adjuvant Therapy (MK-6482-033)Recruiting · Phase 3 · Interventional · 904 enrolled · Merck Sharp & Dohme LLCNCT07227402updated 2026-06-12
- Extension Study for Participants in Studies That Include Belzutifan (MK-6482-043/LITESPARK-043)Recruiting · Phase 3 · Interventional · 450 enrolled · Merck Sharp & Dohme LLCNCT07405164updated 2026-06-12
- A Clinical Study of Belzutifan (MK-6482) and Zanzalintinib in People With Renal Cell Carcinoma (RCC) (LITESPARK-034/LS-034/MK-6482-034)Recruiting · Phase 3 · Interventional · 758 enrolled · Merck Sharp & Dohme LLCNCT07489495updated 2026-06-11
- Phase 1/2 Study TROP2 CAREngineered Cord Blood-Derived NK Cells + Belzutifan In Pancreatic CancerRecruiting · Phase 1 · Phase 2 · Interventional · 37 enrolled · M.D. Anderson Cancer CenterNCT07377526updated 2026-06-11
- Belzutifan/MK-6482 for the Treatment of Advanced Pheochromocytoma/Paraganglioma (PPGL), Pancreatic Neuroendocrine Tumor (pNET), Von Hippel-Lindau (VHL) Disease-Associated Tumors, Advanced Gastrointestinal Stromal Tumor (wt GIST), or Solid Tumors With HIF-2α Related Genetic Alterations (MK-6482-015)Recruiting · Phase 2 · Interventional · 355 enrolled · Merck Sharp & Dohme LLCNCT04924075updated 2026-06-08
- Substudy 03C: A Study of Combination Therapies in Participants With Renal Cell Carcinoma With Recurrent Disease During or After Anti-PD-(L)1 Therapy (MK-3475-03C/KEYMAKER-U03)Recruiting · Phase 1 · Phase 2 · Interventional · 140 enrolled · Merck Sharp & Dohme LLCNCT07049926updated 2026-05-26
- Belzutifan's Role in Active Surveillance Versus Treatment for Indolentmetastatic Clear Cell Renal Ccell Carcinoma (BRAVE-RCC)Recruiting · Phase 2 · Interventional · 78 enrolled · M.D. Anderson Cancer CenterNCT07023432updated 2026-05-22
- A Study of Belzutifan (MK-6482) in Participants With Advanced Clear Cell Renal Cell Carcinoma (MK-6482-018)Completed · Phase 1 · Interventional · 29 enrolled · Merck Sharp & Dohme LLCNCT04846920updated 2026-05-22
- Pembrolizumab Plus Belzutifan With or Without Lenvatinib in Localized Renal Cell CarcinomaNot yet recruiting · Phase 2 · Interventional · 150 enrolled · Vall d'Hebron Institute of OncologyNCT07593040updated 2026-05-20
Frequently asked questions
- How does Belzutifan work?
- Belzutifan is an inhibitor of hypoxia-inducible factor 2 alpha (HIF-2α). HIF-2α is a transcription factor that plays a role in oxygen sensing by regulating genes that promote adaptation to hypoxia.
- What is Belzutifan used for?
- According to FDA labeling, Belzutifan carries indications including: WELIREG is a hypoxia-inducible factor inhibitor indicated: von Hippel-Lindau (VHL) disease for treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system (CNS) hemangioblastomas, or pancreatic neuroendocrine tumors (pNET), not requiring immediate surgery. ( 1.1 ) Advanced Renal Cell Carcinoma (RCC) for treatment of adult patients with advanced renal cell carcinoma (RCC) with a clear cell component following 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).. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
- What class of drug is Belzutifan?
- Belzutifan is classified as Other antineoplastic agents, Hypoxia-inducible Factor Inhibitor, Cytochrome P450 3A4 Inducers, Gene Transcription Modulation, Hypoxia-inducible Factor 2 alpha Inhibitors.
- What are the brand names for Belzutifan?
- Belzutifan is marketed under brand names including Welireg.
- What are the contraindications for Belzutifan?
- Belzutifan labeling lists contraindications including: None. None.. Always consult the full prescribing information and a clinician.
belzutifan is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.