TheraRadar
Data updated: May 26, 2026

WELIREG (belzutifan)

Hypoxia-inducible Factor 2 alpha Inhibitors Trial Activity: Growth 27 active trials
First-in-Class Orphan Drug Priority Review
Oncology Approved 2021-08-13

WELIREG is indicated for the treatment of Von Hippel-Lindau Disease; Renal Cell Carcinoma; Central Nervous System Hemangioblastoma; Pancreatic Neuroendocrine Tumor; Pheochromocytoma; Paraganglioma.

Source: FDA Label • Merck • Hypoxia-inducible Factor Inhibitor

How WELIREG Works

Belzutifan is a selective inhibitor of hypoxia-inducible factor 2 alpha (HIF-2α). In healthy cells, the VHL protein facilitates the degradation of HIF-2α. In patients with VHL disease or certain renal cancers, the lack of functional VHL protein leads to the stabilization and accumulation of HIF-2α. Once stabilized, HIF-2α forms a complex with HIF-1β, acting as a transcription factor that upregulates genes associated with cellular proliferation, angiogenesis, and tumor growth. Belzutifan binds to HIF-2α, blocking its interaction with HIF-1β and thereby reducing the expression of these downstream oncogenic target genes.

Development Insights

Merck Sharp & Dohme LLC conducting 22 trials (69%)
58 indications explored (Broad Platform)
carcinoma, renal cell (11 trials)
renal cell carcinoma (6 trials)
clear cell renal cell carcinoma (3 trials)
4
Indications
--
Phase 3 Trials
3
Priority Reviews
4
Years on Market

Details

Status
Prescription
First Approved
2021-08-13
PDUFA Date
2026-06-19 (24d)
Patent Cliff
2042
Revenue
$160M (Q4-2024)

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Patent cliff and revenue data

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Routes
ORAL
Dosage Forms
TABLET

Companies

Active Ingredient: BELZUTIFAN

WELIREG Approval History

2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
6 FDA actions from 2021 to 2025 · 3 indication expansions
May 2025 SUPPL Priority
Efficacy
Apr 2025 SUPPL
Efficacy
Feb 2024 SUPPL
Label · Labeling

What WELIREG Treats

6 indications

WELIREG is approved for 6 conditions since its original approval in 2021. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Von Hippel-Lindau Disease
  • Renal Cell Carcinoma
  • Central Nervous System Hemangioblastoma
  • Pancreatic Neuroendocrine Tumor
  • Pheochromocytoma
  • Paraganglioma
Source: FDA Label

WELIREG Boxed 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. Exposur...

WELIREG Competitive Set

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Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

What's emerging in WELIREG's indications

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Phase 3 candidates targeting molecules with no FDA-approved drug, in indications WELIREG treats. First-in-class if their pivotal trials read out positive.

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Clinical Trial Registry

33 trials
Trial Sponsor ID Phase Status Title
NCT07049926 3475-03C MK-3475-03C, 2024-516437-12-00 Ph 1, Ph 2 recruiting 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)
NCT07405164 6482-043 U1111-1325-4582, 2025-524160-38-00 Ph 3 recruiting Extension Study for Participants in Studies That Include Belzutifan (MK-6482-043/LITESPARK-043)
NCT07227402 LITESPARK-033 6482-033 U1111-1311-6892, 2024-517136-21 Ph 3 recruiting A Clinical Study of Belzutifan and Zanzalintinib in People With Recurrent Kidney Cancer Following Adjuvant Therapy (MK-6482-033)
NCT07489495 6482-034 U1111-1311-4692, 2024-516993-31-00 Ph 3 recruiting A Clinical Study of Belzutifan (MK-6482) and Zanzalintinib in People With Renal Cell Carcinoma (RCC) (LITESPARK-034/LS-034/MK-6482-034)
NCT04924075 6482-015 MK-6482-015, PT2977 Ph 2 recruiting 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)
NCT04626518 3475-03B MK-3475-03B, KEYMAKER-U03 Ph 1, Ph 2 active not recruiting Substudy 03B: A Study of Immune and Targeted Combination Therapies in Participants With Second Line Plus (2L+) Renal Cell Carcinoma (MK-3475-03B/KEYMAKER-U03)
NCT04626479 3475-03A MK-3475-03A, 2023-506838-68-00 Ph 1, Ph 2 active not recruiting Substudy 03A: A Study of Immune and Targeted Combination Therapies in Participants With First Line (1L) Renal Cell Carcinoma (MK-3475-03A)
NCT04736706 6482-012 MK-6482-012, jRCT2031210435 Ph 3 active not recruiting A Study of Pembrolizumab (MK-3475) in Combination With Belzutifan (MK-6482) and Lenvatinib (MK-7902), or Pembrolizumab/Quavonlimab (MK-1308A) in Combination With Lenvatinib, Versus Pembrolizumab and Lenvatinib, for Treatment of Advanced Clear Cell Renal Cell Carcinoma (MK-6482-012)
NCT04586231 6482-011 MK-6482-011, jRCT2031210311 Ph 3 active not recruiting A Study of Belzutifan (MK-6482) in Combination With Lenvatinib Versus Cabozantinib for Treatment of Renal Cell Carcinoma (MK-6482-011)
NCT05239728 6482-022 MK-6482-022, LITESPARK-022 Ph 3 active not recruiting A Study of Belzutifan (MK-6482) Plus Pembrolizumab (MK-3475) Versus Placebo Plus Pembrolizumab in Participants With Clear Cell Renal Cell Carcinoma Post Nephrectomy (MK-6482-022)
NCT06428396 6482-029 MK-6482-029, LITESPARK-029 Ph 2 recruiting Study of Belzutifan (MK-6482) Plus Fulvestrant for ER+/HER2- Metastatic Breast Cancer (MK-6482-029/LITESPARK-029)
NCT03401788 6482-004 PT2977-202, MK-6482-004 Ph 2 active not recruiting A Phase 2 Study of Belzutifan (PT2977, MK-6482) for the Treatment of Von Hippel Lindau (VHL) Disease-Associated Renal Cell Carcinoma (RCC) (MK-6482-004)
NCT05468697 6482-024 MK-6482-024, LITESPARK-024 Ph 1, Ph 2 active not recruiting A Study of Belzutifan (MK-6482) in Combination With Palbociclib Versus Belzutifan Monotherapy in Participants With Advanced Renal Cell Carcinoma (MK-6482-024/LITESPARK-024)
NCT06234605 HC366-RCC2311 MK-6482-030 Ph 1 recruiting A Study of HC-7366 in Combination With Belzutifan (WELIREG™) in Patients With Renal Cell Carcinoma
NCT07187778 2024-1884 NCI-2025-06635 Ph 2 recruiting Phase II Trial of Single Agent Belzutifan or Pembrolizumab Versus Combination as Neoadjuvant Therapy in Clear Cell Renal Cell Carcinoma (BLAZE)
NCT05030506 6482-010 MK-6482-010 Ph 1 active not recruiting A Study of Belzutifan (MK-6482) as Monotherapy and in Combination With Lenvatinib (E7080/MK-7902) With or Without Pembrolizumab (MK-3475) in China Participants With Advanced Renal Cell Carcinoma (MK-6482-010)
NCT05899049 6482-012 China Extension MK-6482-012 China Extension, jRCT2031210435 Ph 3 active not recruiting A Study of Pembrolizumab (MK-3475) in Combination With Belzutifan (MK-6482) and Lenvatinib (MK-7902), or Pembrolizumab/Quavonlimab (MK-1308A) in Combination With Lenvatinib, vs Pembrolizumab and Lenvatinib, for Treatment of Advanced Clear Cell Renal Cell Carcinoma (MK-6482-012)-China Extension Study
NCT06677190 24-519 Ph 2 recruiting Belzutifan in Recurrent Clear Cell Carcinoma of Gynecologic Origin
NCT07121959 6482-039 MK-6482-039 Ph 1 completed A Study of Belzutifan (MK-6482) and Metformin in Healthy Adult Participants (MK-6482-039)
NCT07179770 24-01254 5K12CA270377-02 Ph 1 recruiting Effects of Belzutifan on 89Zr-DFO-girentuximab PET Uptake in Patients With Renal Cell Carcinoma (RCC)
NCT07167329 BELIEVE-VHL ACCamargoCC Ph 2 recruiting Real-World Effectiveness and Pharmacogenetics of Belzutifan in VHL Syndrome: The BELIEVE-VHL Trial
NCT02974738 6482-001 PT2977-101, MK-6482-001 Ph 1 active not recruiting A Trial of Belzutifan (PT2977, MK-6482) Tablets In Patients With Advanced Solid Tumors (MK-6482-001)
NCT07023432 2025-0268 NCI-2025-04261 Ph 2 not yet recruiting Belzutifan's Role in Active Surveillance Versus Treatment for Indolentmetastatic Clear Cell Renal Ccell Carcinoma (BRAVE-RCC)
NCT06903715 6482-035 CA46602 Ph 1 completed A Clinical Study of Belzutifan (MK-6482) Alone or With Phenytoin in Healthy Participants (CA46602/MK-6482-035)
NCT04195750 results posted 6482-005 MK-6482, 205262 Ph 3 active not recruiting A Study of Belzutifan (MK-6482) Versus Everolimus in Participants With Advanced Renal Cell Carcinoma (MK-6482-005)
NCT04994522 results posted 6482-021 MK-6482-021 Ph 1 completed A Study of Belzutifan (MK-6482) in Participants With Renal Impairment (MK-6482-021)
NCT04976634 6482-016 MK-6482-016, 2023-503905-12-00 Ph 2 active not recruiting Pembrolizumab Plus Lenvatinib in Combination With Belzutifan in Solid Tumors (MK-6482-016)
NCT04489771 results posted 6482-013 MK-6482-013, 2022-502123-21-00 Ph 2 active not recruiting A Study of Belzutifan (MK-6482) in Participants With Advanced Renal Cell Carcinoma (MK-6482-013)
NCT04995484 results posted 6482-020 MK-6482-020 Ph 1 completed A Study of Belzutifan (MK-6482) in Participants With Hepatic Impairment (MK-6482-020)
NCT03634540 6482-003 PT2977-201, MK-6482-003 Ph 2 active not recruiting A Trial of Belzutifan (PT2977, MK-6482) in Combination With Cabozantinib in Patients With Clear Cell Renal Cell Carcinoma (ccRCC) (MK-6482-003)
NCT04846920 6482-018 MK-6482-018 Ph 1 active not recruiting A Study of Belzutifan (MK-6482) in Participants With Advanced Clear Cell Renal Cell Carcinoma (MK-6482-018)
NCT03445169 6482-002 PT2977-103 Ph 1 completed A Food Effect Study in Healthy Volunteers With Belzutifan (PT2977, MK-6482) Tablets
NCT07593040 Moonlanding VHIO24002 2024-519673-18-00 Ph 2 not yet recruiting Pembrolizumab Plus Belzutifan With or Without Lenvatinib in Localized Renal Cell Carcinoma
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Active Pipeline

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

WELIREG FDA Label Details

Indications & Usage

FDA Label (PDF)

WELIREG is indicated for the treatment of Von Hippel-Lindau Disease; Renal Cell Carcinoma; Central Nervous System Hemangioblastoma; Pancreatic Neuroendocrine Tumor; Pheochromocytoma; Paraganglioma.

⚠️ BOXED WARNING

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 ineffecti...

View full patent landscape →
3 OB patents · 2 families · 104 international docs across 35 countries

WELIREG Patents & Exclusivity

Latest Patent: Jun 2042
Exclusivity: Aug 2028

Patents (3 active)

US12358870 Expires Jun 30, 2042
USRE49948 Expires Sep 5, 2034
US9908845 Expires Sep 5, 2034

Exclusivity

I-931 Until Dec 2026
I-968 Until May 2028
NCE Until Aug 2026
ODE-364 Until Aug 2028
Source: FDA Orange Book

Pro Intelligence Preview

Deep insights for WELIREG

Revenue Insights

  • Q4-2024: $160M
  • Historical trend analysis

Patent Timeline

  • Cliff: 2042
  • 7 active patents

Trial Analysis

  • 32 total trials
  • Stage: Growth

Competitive Landscape

  • 20 similar drugs
  • Same target/indication analysis
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Full approval history • All patents • Revenue trends • Competitor analysis

Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.

How We Calculate These Metrics

Trial Activity Stage

Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.

Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.

  • Growth: High proportion of early-phase trials (Phase 1/2), active development
  • Expansion: Significant Phase 3 activity, approaching or pursuing approvals
  • Mature: Substantial Phase 4 post-marketing studies
  • Stable: Mixed phase distribution, steady development
  • Declining: Low active trial ratio, reduced R&D investment