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Welireg (BELZUTIFAN)
Welireg (generic name: BELZUTIFAN) is a Hypoxia-inducible Factor Inhibitor [EPC] Small molecule drug developed by Merck & Co.. It is currently FDA-approved (first approved 2021) for von Hippel-Lindau (VHL) disease, Advanced Renal Cell Carcinoma (RCC), Pheochromocytoma or Paraganglioma (PPGL).
Belzutifan inhibits HIF-2α, blocking its interaction with HIF-1β to reduce expression of genes linked to tumor growth.
Belzutifan (Welireg), marketed by Merck & Co., is an HIF-2α inhibitor approved for the treatment of von Hippel-Lindau (VHL) disease. Its key strength lies in its unique mechanism of action, which blocks the interaction between HIF-2α and HIF-1β, thereby reducing the expression of genes linked to tumor growth. The primary risk is the key composition patent expiry in 2028, which could lead to increased competition from generics.
At a glance
| Generic name | BELZUTIFAN |
|---|---|
| Sponsor | Merck & Co. |
| Drug class | Hypoxia-inducible Factor Inhibitor [EPC] |
| Target | HIF-2α |
| Modality | Small molecule |
| Therapeutic area | Oncology |
| Phase | FDA-approved |
| First approval | 2021 |
| Annual revenue | 509 |
Mechanism of action
Belzutifan works by targeting HIF-2α, a protein that helps cells adapt to low oxygen levels. When HIF-2α is stabilized due to lack of VHL protein, it promotes gene expression that supports tumor growth. Belzutifan binds to HIF-2α and prevents it from forming a complex with HIF-1β, thereby reducing the expression of these genes.
Approved indications
- von Hippel-Lindau (VHL) disease
- Advanced Renal Cell Carcinoma (RCC)
- Pheochromocytoma or Paraganglioma (PPGL)
Boxed warnings
- 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 )
Common side effects
- decreased hemoglobin
- fatigue
- headache
- dizziness
- nausea
- constipation
- abdominal pain
- visual impairment
- upper respiratory tract infection
- dyspnea
- arthralgia
- myalgia
Drug interactions
- UGT2B17 or CYP2C19 Inhibitors
- CYP3A4 Substrates
- Hormonal Contraceptives
Key clinical trials
- A Clinical Study of Belzutifan and Zanzalintinib in People With Recurrent Kidney Cancer Following Adjuvant Therapy (MK-6482-033) (PHASE3)
- A Clinical Study of Belzutifan (MK-6482) and Zanzalintinib in People With Renal Cell Carcinoma (RCC) (LITESPARK-034/LS-034/MK-6482-034) (PHASE3)
- Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029) (PHASE2)
- Drug Screening Using Novel IMD in Renal Cell Carcinoma (PHASE1)
- 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) (PHASE1,PHASE2)
- Extension Study for Participants in Studies That Include Belzutifan (MK-6482-043/LITESPARK-043) (PHASE3)
- A Study of Belzutifan (MK-6482) in Combination With Lenvatinib Versus Cabozantinib for Treatment of Renal Cell Carcinoma (MK-6482-011) (PHASE3)
- 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) (PHASE2)
Patents
| Patent | Expiry | Type |
|---|---|---|
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
| FDA Orange Book | Patents + exclusivity |
| SEC EDGAR | Revenue + earnings |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Welireg CI brief — competitive landscape report
- Welireg updates RSS · CI watch RSS
- Merck & Co. portfolio CI
Frequently asked questions about Welireg
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Related
- Drug class: All Hypoxia-inducible Factor Inhibitor [EPC] drugs
- Target: All drugs targeting HIF-2α
- Manufacturer: Merck & Co. — full pipeline
- Therapeutic area: All drugs in Oncology
- Indication: Drugs for von Hippel-Lindau (VHL) disease
- Indication: Drugs for Advanced Renal Cell Carcinoma (RCC)
- Indication: Drugs for Pheochromocytoma or Paraganglioma (PPGL)
Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing