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HIF-2α inhibitor

Belzutifan

Welireg · Belzu

HIF-2α inhibitor · approved 2021 · 7 references

A HIF-2α inhibitor whose on-target anemia and hypoxia define its profile — kidney injury is largely indirect.

Signature injury
Prerenal / Hemodynamic AKI
Severity
Mild
Reversibility
Reversible
Onset
Anemia and hypoxia develop over the first weeks of therapy.

Signature kidney injury & incidence

Prerenal / Hemodynamic AKI.

Anemia is the most common on-target adverse event (the leading grade 3 event in pivotal trials) and hypoxia is frequent. Direct nephrotoxicity is not a prominent or well-quantified signal; renal function changes mostly reflect underlying RCC/nephrectomy status.

Source: Choueiri et al., NEJM 2024 (LITESPARK-005; anemia leading G3 event)

Reported injury signatures: Prerenal / Hemodynamic AKI.

Onset timing & rechallenge

Subacute (~1–6 weeks) — Anemia and hypoxia emerge over the first weeks of therapy.

Mechanism of kidney injury

By suppressing HIF-2α–mediated erythropoietin transcription, belzutifan causes anemia (and consequent hypoxia/fatigue). Any renal compromise is mostly indirect — hemodynamic or related to reduced oxygen delivery — rather than a defined tubular or glomerular lesion. Many patients have a solitary or operated kidney from prior RCC surgery, so any superimposed insult (anemia-related hypoperfusion, volume depletion, contrast, other nephrotoxins) has outsized impact.

Clinical presentation

Anemia, hypoxia (sometimes requiring supplemental oxygen) and fatigue dominate. Serum creatinine is usually stable; renal changes typically reflect tumor burden or post-nephrectomy reduced nephron mass rather than drug tubulotoxicity.

Management

Dose-modify or hold for severe anemia/hypoxia (from 120 mg daily); transfuse/ESA support as needed; supplemental oxygen for hypoxia. Monitor renal function closely in patients with reduced functional renal mass.

Risk factors

  • Solitary or operated kidney (reduced nephron mass)
  • Baseline anemia or cardiopulmonary disease
  • Volume depletion
  • Concurrent nephrotoxins/contrast

Prevention

  • Erythropoiesis-stimulating agents or transfusion per anemia guidance
  • Maintain hydration; minimize nephrotoxin/contrast exposure in reduced-nephron patients

Renal dose adjustment

No baseline renal dose change per the FDA label, including ESKD; in severe impairment (eGFR 15-29, MDRD) the label directs monitoring for increased adverse reactions and modifying the dose accordingly. Standard 120 mg once daily; modifications are driven by anemia and hypoxia rather than CrCl.

Dialyzability & ESKD dosing

Not characterized; belzutifan is highly protein-bound and primarily metabolized by UGT2B17/CYP2C19, so it is unlikely to be substantially removed by dialysis. No ESKD dosing guidance exists.

Differential diagnosis

Distinguish anemia-driven fatigue/hypoxia (the expected on-target effect) from cardiopulmonary or hemorrhagic causes; separate a creatinine change due to reduced post-nephrectomy nephron mass or volume depletion from any true drug-related lesion (rare).

Monitoring

  • Hemoglobin at baseline and periodically (anemia is the signature toxicity)
  • Oxygen saturation / assessment for hypoxia
  • Serum creatinine in patients with solitary or operated kidneys

Key trials & series

  • Choueiri et al., NEJM 2024 — LITESPARK-005 phase 3 (belzutifan vs everolimus in advanced ccRCC; registrational; anemia leading grade 3 event)
  • Jonasch et al., NEJM 2021 — LITESPARK-004 (VHL-associated RCC)
  • Iliopoulos et al., Lancet Oncol 2024 — LITESPARK-004 VHL CNS hemangioblastomas

Clinical pearls

  • Belzutifan's signature toxicity is on-target anemia (suppressed EPO) — anticipate it, monitor hemoglobin, and support rather than reflexively stop the drug.
  • Many recipients have a single working kidney from RCC surgery, so protect renal reserve aggressively.
  • Hypoxia can occur even without anemia and may need supplemental oxygen; it is a mechanism-based, expected effect.

Anticancer mechanism

First-in-class oral inhibitor of hypoxia-inducible factor-2α (HIF-2α). In VHL-deficient clear-cell renal cell carcinoma (ccRCC), loss of the von Hippel-Lindau protein stabilizes HIF-2α, which drives transcription of VEGF, cyclin D1, EPO and other pro-tumor/angiogenic genes; belzutifan blocks HIF-2α from dimerizing with HIF-1β/ARNT, shutting down this program in ccRCC and VHL-disease–associated tumors.

Note

The dominant, well-characterized toxicities are anemia and hypoxia — direct on-target consequences of HIF-2α/EPO suppression — not direct nephrotoxicity. The renal profile is still emerging.

Guidelines & consensus

Each recommendation below is this atlas's faithful summary of the source, not a quotation from it — follow the PubMed link for the wording the society published. Summaries may be superseded; consult the current full text and individualize to the patient.

  • ADQI (2026) — The nephrotoxic effects of anti-cancer therapies: consensus report of the 34th Acute Disease Quality Initiative workgroupProvides expert-based statements (modified Delphi) on preventing and managing cisplatin/platinum-associated AKI, including isotonic IV hydration, attention to volume status and concomitant nephrotoxins, and incorporates evidence that IV magnesium supplementation may reduce cisplatin-associated AKI; emphasizes risk stratification and standardized AKI definitions.Nat Rev Nephrol · PMID 41361704
  • SIRM (2022) — SIRM-SIN-AIOM: appropriateness criteria for evaluation and prevention of renal damage in the patient undergoing contrast medium examinations-consensus statements from Italian College of Radiology (SIRM), Italian College of Nephrology (SIN) and Italian Association of Medical Oncology (AIOM)Recommends eGFR-based renal risk assessment and pre/post-contrast isotonic saline or sodium bicarbonate hydration; advises maintaining a 5-7 day interval between iodinated contrast administration and cisplatin in cancer patients to reduce additive nephrotoxicity.Radiol Med · PMID 35303246
  • KDIGO (2020) — KDIGO Controversies Conference on onco-nephrology: understanding kidney impairment and solid-organ malignancies, and managing kidney cancerIdentifies platinum compounds (especially cisplatin) as leading cytotoxic causes of acute tubular injury, AKI, and electrolyte/magnesium wasting; calls for interdisciplinary onco-nephrology care, accurate GFR estimation, and individualized drug dosing in patients with reduced kidney function.Kidney Int · PMID 33126977
  • KDIGO (2020) — KDIGO Controversies Conference on onco-nephrology: kidney disease in hematological malignancies and the burden of cancer after kidney transplantationAddresses chemotherapy-associated AKI/CKD in hematologic cancer, GFR estimation and chemotherapy dosing in patients with reduced kidney function, and management priorities and research gaps for onco-nephrology care.Kidney Int · PMID 33276867
  • ADDIKD (2025) — Integrating International Consensus Guidelines for Anticancer Drug Dosing in Kidney Dysfunction (ADDIKD) into everyday practiceProvides GRADE-based, drug-specific dose-adjustment recommendations for anticancer agents in kidney dysfunction (illustrated for methotrexate, cisplatin, carboplatin and nivolumab); the recommendations build on Part 1's standardised CKD-EPI eGFR assessment rather than Cockcroft-Gault creatinine clearance.EClinicalMedicine · PMID 40290844
  • ADDIKD (2025) — Aligning kidney function assessment in patients with cancer to global practices in internal medicineThree consensus recommendations: assess kidney function by GFR (measured GFR or CKD-EPI eGFR), classify it using KDIGO categories, and use this uniform approach to dose anticancer drugs — moving cancer medicine away from Cockcroft-Gault estimated creatinine clearance.EClinicalMedicine · PMID 40290845
  • ADDIKD (2025) — A methodology for determining dosing recommendations for anticancer drugs in patients with reduced kidney functionEstablishes that, where RCT evidence is lacking, anticancer drug dosing recommendations in kidney dysfunction should be derived by critically appraising observational literature via GRADE combined with structured international multidisciplinary consensus voting.EClinicalMedicine · PMID 40290846
  • KDIGO (2013) — Diagnosis, evaluation, and management of acute kidney injury: a KDIGO summary (Part 1)Defines/stages AKI by serum creatinine and urine output; emphasizes avoiding nephrotoxins, maintaining euvolemia/perfusion, dose-adjusting drugs to kidney function, and monitoring high-risk patients — the framework applied to nephrotoxic anti-cancer agents.Crit Care · PMID 23394211
  • KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknownsEvaluate and risk-stratify CKD, manage to delay progression and its complications, and practise explicit medication management and drug stewardship — the framework the atlas's G1–G5 eGFR banding and every renal dose-adjustment recommendation sit inside. Because the guideline excludes dialysis and transplant recipients by its own statement of scope, its recommendations do not carry to those settings, where this atlas's dialyzability and post-transplant guidance rests on other sources.Kidney Int · PMID 38519239
  • KDIGO (2021) — Executive summary of the KDIGO 2021 Guideline for the Management of Glomerular DiseasesProvides the staging/treatment framework for drug-associated glomerular lesions (e.g., bisphosphonate- and interferon-related collapsing FSGS, VEGF-inhibitor podocytopathy/proteinuria), including immunosuppression and supportive RAAS-blockade strategies.Kidney Int · PMID 34556300
  • KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of ANCA-Associated VasculitisUpdates immunosuppressive induction (rituximab/cyclophosphamide), incorporates avacopan and lower-dose or glucocorticoid-sparing regimens — the management framework for drug- and checkpoint-inhibitor-associated ANCA/pauci-immune glomerulonephritis.Kidney Int · PMID 38388147
  • KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of Lupus NephritisUpdates first-line lupus nephritis therapy to combination immunosuppression with the addition of belimumab or a calcineurin inhibitor (voclosporin) — informs management of immune-complex/lupus-like glomerulonephritis encountered with immunotherapy.Kidney Int · PMID 38182299
  • KDIGO (2025) — Executive summary of the KDIGO 2025 Clinical Practice Guideline for the Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV)Encourages liberal kidney biopsy and stricter proteinuria control (<0.5 g/d, ideally <0.3 g/d) with RAAS blockers, SGLT2 inhibitors, and targeted-release budesonide — the framework for IgA-dominant glomerular lesions, including those triggered by immune-modulating cancer therapy.Kidney Int · PMID 40975525

References

7 peer-reviewed references. Citation metadata via PubMed / NLM.

  1. 1.Belzutifan versus Everolimus for Advanced Renal-Cell Carcinoma.Choueiri TK et al. · N Engl J Med · 2024 · PMID 39167807
  2. 2.Inhibition of hypoxia-inducible factor-2α in renal cell carcinoma with belzutifan: a phase 1 trial and biomarker analysis.Choueiri TK et al. · Nat Med · 2021 · PMID 33888901
  3. 3.Belzutifan for Renal Cell Carcinoma in von Hippel-Lindau Disease.Jonasch E et al. · N Engl J Med · 2021 · PMID 34818478
  4. 4.Belzutifan for patients with von Hippel-Lindau disease-associated CNS haemangioblastomas (LITESPARK-004): a multicentre, single-arm, phase 2 study.Iliopoulos O et al. · Lancet Oncol · 2024 · PMID 39284337
  5. 5.Health-related quality of life with belzutifan versus everolimus for advanced renal cell carcinoma (LITESPARK-005): patient-reported outcomes from a randomised, open-label, phase 3 trial.Powles T et al. · Lancet Oncol · 2025 · PMID 40112850
  6. 6.Belzutifan-Associated Hypoxia: A Review of the Novel Therapeutic, Proposed Mechanisms of Hypoxia, and Management Recommendations.Kucharczyk J et al. · Int J Mol Sci · 2025 · PMID 40806229
  7. 7.Targeting HIF-2α: the role of belzutifan in clear cell renal carcinoma management.Valdés A et al. · Expert Rev Clin Pharmacol · 2024 · PMID 39670660
Educational monograph from NephTox (nephtox.com). Not medical advice — verify against current guidelines before any clinical decision.