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Drug

Belzutifan

Approved · FDA / EMA
ClassEndothelial PAS domain-containing protein 1 inhibitorEmerging researchLate-stage development

Also known as Welireg.

RxNorm2567226ChEMBLCHEMBL4585668ATCL01XX74UNII7K28NB895L
1
Research papers
29
Active clinical trials
EPAS1
Primary target
8
Regulatory events
Latest activity
beta

Recent clinical, regulatory, research and industry developments relating to this drug.

A Phase 1b/2 Study of Immune and Targeted Combination Therapies in Participants With RCC (U03): Substudy 03A in First Line Metastatic Participants

Clinical trial2026-07-30Results expected Q3 2026 · ClinicalTrials.gov

A Multicenter, Open-label, Randomized, Phase 1/2 Study of Belzutifan in Combination With Palbociclib Versus Belzutifan Monotherapy in Participants With Advanced Renal Cell Carcinoma

Clinical trial2026-07-21Primary completion · ClinicalTrials.gov

A Phase 1b/2 Study of Immune and Targeted Combination Therapies in Participants With RCC (KEYMAKER-U03): Substudy 03B in Second-Line Metastatic Participants

Clinical trial2026-07-17Primary completion · ClinicalTrials.gov

Phase Ib/II Trial of Pembrolizumab (MK-3475) Combination Therapies in Metastatic Castration-Resistant Prostate Cancer (mCRPC) (KEYNOTE-365)

Clinical trial2026-07-13Results expected Q4 2027 · ClinicalTrials.gov

A Multicenter, Open-label, Phase 3 Extension Study to Evaluate the Long-term Efficacy and Safety in Participants Who Are Currently on Treatment in a Belzutifan Study (LITESPARK-043)

Clinical trial2026-07-10Results expected Q1 2034 · ClinicalTrials.gov

A Phase 1b/2 Study of Immune and Targeted Combination Therapies in Participants With RCC (KEYMAKER-U03): Substudy 03C in Participants With Recurrent Disease During or After Anti-PD-(L)1 Adjuvant Therapy

Clinical trial2026-07-10Results expected Q4 2031 · ClinicalTrials.gov

Merck's Welireg-Keytruda pairing sticks the landing in adjuvant kidney cancer treatment with new FDA nod

Regulatory2026-06-15Regulatory news · Fierce Pharma

Indication expansion: BELZUTIFAN (NDA215383)

Regulatory2026-06-12FDA

Indication expansion: BELZUTIFAN (NDA215383)

Regulatory2025-05-14FDA

Indication expansion: BELZUTIFAN (NDA215383)

Regulatory2025-04-15FDA

Indication expansion: BELZUTIFAN (NDA215383)

Regulatory2025-04-15FDA

Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.

Research2021-11-01The New England journal of medicine

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name
Belzutifan
Aliases & brands
Welireg
RxNorm CUI
2567226
ChEMBL ID
CHEMBL4585668
ATC codes
L01XX74
UNII
7K28NB895L
Primary mechanism
Endothelial PAS domain-containing protein 1 inhibitor
Regulatory jurisdictions
emafda

Pharmacology & targets

1 target

Known molecular targets and mechanisms supported by curated pharmacology databases.

Endothelial PAS domain-containing protein 1
EPAS1 · Q99814
INHIBITOREndothelial PAS domain-containing protein 1 inhibitor

Regulatory timeline

8 events

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Approval / market entry confirmed across FDA and EMA (2023-12-14 → 2025-05-14)
Earliest approval
2021-08-13
Latest approval
2026-06-12
Authorities
FDA · EMA
Total events
8
fdaU.S. Food and Drug Administration· 7 events
2026-06-12Indication expansion
Indication expansion: BELZUTIFAN (NDA215383)
Evidence ↗
2025-05-14Indication expansionMulti-authority
Indication expansion: BELZUTIFAN (NDA215383)
Evidence ↗
2025-04-15Indication expansionMulti-authority
Indication expansion: BELZUTIFAN (NDA215383)
Evidence ↗
emaEuropean Medicines Agency· 1 event
2025-02-12ApprovalMulti-authority
Approval: Welireg (EMA)
Indication: Renal cell carcinoma (RCC) Welireg is indicated as monotherapy for the treatment of adult patients with advanced clear cell renal cell carcinoma that progressed following two or… Show full indication

Renal cell carcinoma (RCC) Welireg is indicated as monotherapy for the treatment of adult patients with advanced clear cell renal cell carcinoma that progressed following two or more lines of therapy that included a PD-(L)1 inhibitor and at least two VEGF-targeted therapies. von Hippel-Lindau (VHL) disease-associated tumours Welireg is indicated as monotherapy for the treatment of adult patients with von Hippel-Lindau disease who require therapy for associated, localised renal cell carcinoma (RCC), central nervous system (CNS) haemangioblastomas, or pancreatic neuroendocrine tumours (pNET), and for whom localised procedures are unsuitable.

Evidence ↗

Data from the U.S. Food and Drug Administration (U.S. Food and Drug Administration), public domain (CC0).

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

35 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme
CLINICALTRIALS.GOV · LIVE REGISTRY
35
registered trials across all phases
LATEST COMPLETION 2026
29
Active studies
13
Recruiting
8
Late-stage (III+)
6
Completed
PHASE DISTRIBUTIONn = 35
Phase 110Phase 1 / 25Phase 212Phase 38

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

A Multicenter, Open-label, Phase 3 Extension Study to Evaluate the Long-term Efficacy and Safety in Participants Who Are Currently on Treatment in a Belzutifan Study (LITESPARK-043)

RecruitingPH IIIMerck Sharp & Dohme LLCn=4502034

A Phase 3, Randomized, Open-label Study of Belzutifan + Zanzalintinib Versus Cabozantinib in Participants With Advanced RCC Who Experienced Disease Recurrence During or After Prior Adjuvant Anti-PD-1/L1 Therapy (LITESPARK-033)

RecruitingPH IIIMerck Sharp & Dohme LLCn=9042032

A Phase 3, Randomized, Double-blind, Study of Belzutifan + Zanzalintinib Versus Belzutifan + Placebo in Participants With Advanced RCC Who Have Progressed on or After Both PD-1/L1 and VEGF-TKI Therapies in Sequence or in Combination (LITESPARK-034)

RecruitingPH IIIMerck Sharp & Dohme LLCn=7582030

A Multicenter, Double-blind, Randomized Phase 3 Study to Compare the Efficacy and Safety of Belzutifan (MK-6482) Plus Pembrolizumab (MK-3475) Versus Placebo Plus Pembrolizumab in the Adjuvant Treatment of Clear Cell Renal Cell Carcinoma (ccRCC) Post Nephrectomy (MK-6482-022)

Active, not recruitingPH IIIKey trialMerck Sharp & Dohme LLCn=1,8002029

An Open-label, Randomized Phase 3 Study to Evaluate Efficacy and Safety of Pembrolizumab (MK-3475) in Combination With Belzutifan (MK-6482) and Lenvatinib (MK-7902), or MK-1308A in Combination With Lenvatinib, Versus Pembrolizumab and Lenvatinib, as First-Line Treatment in Participants With Advanced Clear Cell Renal Cell Carcinoma (ccRCC)

Active, not recruitingPH IIIMerck Sharp & Dohme LLCn=2492027

Recent completions

Trials that read out recently, adding to the completed evidence base.

A Phase 1, Dose-escalation Study to Evaluate Safety and Tolerability of Belzutifan (MK-6482) in Participants With Advanced Clear Cell Renal Cell Carcinoma (ccRCC)

CompletedPH IMerck Sharp & Dohme LLCn=292026

An Open-Label, Phase 1 Study to Characterize the Effects of Belzutifan on the Pharmacokinetics of a MATE1/2K Substrate, Metformin, in Healthy Adult Participants

CompletedPH IMerck Sharp & Dohme LLCn=142025

An Open-Label, Phase 1 Study to Characterize the Effects of Phenytoin on the Pharmacokinetics of Belzutifan in Healthy Adult Participants

CompletedPH IMerck Sharp & Dohme LLCn=142025

An Open-Label, Single-Dose Study to Investigate the Influence of Renal Impairment on the Pharmacokinetics of MK-6482

CompletedPH IMerck Sharp & Dohme LLCn=142024

An Open-Label, Single-Dose Study to Investigate the Influence of Hepatic Impairment on the Pharmacokinetics of MK-6482

CompletedPH IMerck Sharp & Dohme LLCn=172024

A Single-Dose, Open-Label, Randomized, Food Effect Study in Healthy Volunteers With PT2977 Tablets

CompletedPH IPeloton Therapeutics, Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)n=162018

Research activity

1 papers

Key research shaping understanding of this drug, combining the latest publications with the most influential evidence.

Most influential

Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.

The New England journal of medicine · 2021 · 532 cites
Recent papers

Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.

The New England journal of medicine · 2021 · 532 cites
Journals, researchers & institutions
Top journals
  • The New England journal of medicine1
Leading researchers
  • Donskov F1
  • Else T1
  • Iliopoulos O1
  • Jonasch E1
  • Linehan WM1
  • Maranchie JK1
  • Maughan BL1
  • Narayan VK1
Leading institutions
free-text, unnormalised
  • From the University of Texas M.D. Anderson Cancer Center1
References & data sources
  • RxNorm (U.S. National Library of Medicine) — drug identity
  • ChEMBL (EMBL-EBI) & UniProt — pharmacology and targets
  • Europe PMC — research literature
  • ClinicalTrials.gov — clinical trials
  • Regulatory event sources are credited in the Regulatory Timeline above.