Skip to content
IgG Kappa Multiple Myeloma with Cutaneous Plasmacytoma and Hypereosinophilic Leukocytosis in a Young Patient: A Rare Case Report
Back to full profile

BRAF inhibitor

Vemurafenib

Zelboraf · VEM

BRAF inhibitor · approved 2011 · 6 references

The first-in-class BRAF inhibitor that transformed melanoma — and, nearly alone in its class, injures the proximal tubule.

Signature injury
Acute Tubular Necrosis
Severity
Moderate
Reversibility
Partially reversible
Onset
Early — most cases arise within the first weeks to three months of therapy (all AKI events in the Teuma cohort occurred in the first trimester of treatment); later onset is uncommon.

Signature kidney injury & incidence

Acute Tubular Necrosis.

Clinically meaningful AKI is a recognized but variably quantified effect, and vemurafenib is the strongest renal offender of the BRAF/MEK class. Small serum-creatinine rises are common and usually low-grade; overt AKI produced the first case series of 8 patients with significant-to-severe renal insufficiency (Launay-Vacher, Cancer 2014) and 132 vemurafenib AKI reports to FDA FAERS over 3 years, far exceeding dabrafenib's 13 (Jhaveri, JAMA Oncol 2015). In a single-center cohort treated with vemurafenib plus cobimetinib, 24% developed AKI, all within the first three months and mostly KDIGO stage 1-2, and adding the MEK inhibitor reduced AKI incidence roughly 60% versus vemurafenib monotherapy (Teuma 2017). A clean denominator-based monotherapy incidence is not established, so a single headline percentage is deliberately left unquantified.

Source: Teuma et al., Cancer Chemother Pharmacol 2017; Jhaveri et al., JAMA Oncol 2015

Reported injury signatures: Acute Tubular Necrosis, Fanconi Syndrome, Electrolyte Disturbance, Chronic Interstitial Nephropathy.

Renal toxicity profile

  1. Acute Tubular NecrosisPrimary
  2. Fanconi SyndromeSecondary
  3. Electrolyte DisturbanceSecondary
  4. Chronic Interstitial NephropathySecondary

Onset timing & rechallenge

Subacute (~1–6 weeks) — Most AKI arises within the first weeks to three months of therapy; later onset is uncommon.

Mechanism of kidney injury

Predominantly direct, off-target (MAPK-independent) proximal tubular epithelial toxicity. In human cell work, vemurafenib reduced viability and increased cell death in proximal renal tubular epithelial cells (RPTEC) and glomerular epithelial cells (podocytes) at 10 microM — below its steady-state blood Cmax (~115 microM) — while sparing glomerular endothelial cells, and its intrinsic cytotoxicity exceeded that of dabrafenib, cobimetinib, and trametinib (Sanagawa 2021). This tubular injury manifests histologically as acute tubular injury/necrosis, with proximal tubular dysfunction (Fanconi-type glycosuria, phosphaturia, low-molecular-weight proteinuria) and electrolyte wasting in some cases; a tubulointerstitial/interstitial-nephritis component has also been described on the limited biopsy literature (Jhaveri 2015). Concurrent volume depletion from drug-related fever, diarrhea, and reduced intake frequently adds a prerenal/ischemic hit on top of the intrinsic tubular toxicity.

Clinical presentation

Usually an asymptomatic rise in serum creatinine detected on routine labs, often accompanied by electrolyte abnormalities — hypokalemia, hyponatremia, and hypophosphatemia are reported. Proximal tubulopathy (glycosuria with normal glucose, phosphaturia, aminoaciduria, LMW proteinuria) points to Fanconi-type injury. Most episodes are low-grade (CTCAE/KDIGO stage 1-2), but severe AKI requiring drug interruption and, rarely, dialysis has occurred, and some patients are left with persistent CKD. A striking, unexplained male predominance was seen in FAERS (85 men vs 47 women; p<.001).

Management

Confirm the creatinine rise and screen for reversible contributors — volume depletion (very common with vemurafenib fever/diarrhea), other nephrotoxins, obstruction, and contrast. For drug-attributable AKI, hold vemurafenib, restore volume, and replete electrolytes (potassium, phosphate, sodium, magnesium). Most low-grade injury recovers with interruption; on recovery, resume at a reduced dose with close monitoring, and permanently discontinue for recurrent or severe injury. Adding a MEK inhibitor (cobimetinib) both improves outcomes and reduces AKI frequency/severity roughly 60% versus monotherapy (Teuma 2017). If biopsy shows acute interstitial nephritis, a corticosteroid course may be considered (limited evidence). Persistent, severe, or diagnostically unclear injury warrants nephrology referral and consideration of kidney biopsy.

Risk factors

  • Male sex (marked predominance in pharmacovigilance data)
  • Volume depletion from drug-related fever, diarrhea, nausea, or reduced oral intake
  • Concomitant nephrotoxins (NSAIDs, RAAS inhibitors, diuretics, iodinated contrast)
  • Higher drug exposure / prolonged therapy
  • Pre-existing CKD (worsens tolerance of any AKI, though the Teuma cohort paradoxically found better baseline GFR in those who developed AKI — pre-existing impairment is not a prerequisite)

Prevention

  • Check baseline serum creatinine/eGFR and electrolytes, then monitor at least monthly on therapy
  • Maintain euvolemia; counsel on hydration and prompt reporting of fever, diarrhea, or poor intake
  • Avoid stacking nephrotoxins (NSAIDs, contrast, high-dose diuretics/RAAS blockade) where possible
  • Consider combination with a MEK inhibitor (cobimetinib), which lowers AKI incidence and severity while improving efficacy
  • Hold or bridge dosing around intercurrent volume-depleting illness

Renal dose adjustment

No renal-based dose adjustment is specified for mild-to-moderate impairment. Because vemurafenib is hepatically metabolized (CYP3A4) and eliminated almost entirely in feces, with only ~1% renal excretion, exposure is not expected to change materially with reduced GFR, though data in severe impairment and ESKD are lacking. Dose modification is therefore driven by toxicity, not clearance: for drug-attributable AKI or intolerable toxicity, interrupt and, on recovery, resume at reduced dose (label steps 960 -> 720 -> 480 mg twice daily); permanently discontinue for recurrent severe events. Do not reduce below 480 mg twice daily.

Dialyzability & ESKD dosing

Not meaningfully dialyzable. Vemurafenib is >99% protein-bound, highly lipophilic, and eliminated predominantly in feces (~94%) with renal excretion near 1%; hemodialysis is not expected to remove appreciable drug and no post-dialysis supplemental dose is indicated. Dedicated dialysis pharmacokinetic data are lacking.

Differential diagnosis

Separate direct vemurafenib tubular toxicity/ATN from (1) prerenal azotemia due to the drug's fever, diarrhea, and anorexia (low FeNa, responds to volume — often coexists); (2) acute interstitial nephritis (sterile pyuria, eosinophiluria, rash/fever/eosinophilia, sometimes from a concomitant drug); (3) other nephrotoxins and iodinated contrast; and (4) melanoma-related obstruction or renal infiltration. Early onset (first trimester), proximal tubular electrolyte wasting (hypokalemia, hypophosphatemia, glycosuria), and the characteristic male predominance favor vemurafenib tubular toxicity; a lower renal signal with dabrafenib supports an agent-specific effect rather than a pure MAPK-pathway class effect.

Monitoring

  • Baseline and at least monthly serum creatinine/eGFR
  • Serum electrolytes each cycle — potassium, sodium, phosphate, magnesium (proximal tubular wasting)
  • Urinalysis for glycosuria, phosphaturia, or proteinuria when tubulopathy/Fanconi is suspected
  • Volume status and symptoms of fever/diarrhea that precipitate prerenal injury
  • Reassess renal recovery after any dose hold before resuming

Key trials & series

  • BRIM-3 (Chapman, NEJM 2011): phase 3 registrational trial vs dacarbazine establishing survival benefit; renal toxicity was not flagged in the pivotal safety profile, and the nephrotoxicity signal emerged post-marketing
  • Jhaveri (JAMA Oncol 2015): FAERS pharmacovigilance analysis defining the class signal — 132 vemurafenib AKI reports vs 13 for dabrafenib, with male predominance
  • Teuma (Cancer Chemother Pharmacol 2017): single-center cohort showing 24% AKI on vemurafenib+cobimetinib and ~60% AKI reduction from adding the MEK inhibitor
  • Sanagawa (Anticancer Drugs 2021): real-world FAERS ROR plus human-cell work localizing direct cytotoxicity to proximal tubular and glomerular epithelial cells

Clinical pearls

  • Vemurafenib is the outlier of the BRAF/MEK class for kidney injury — FAERS AKI ROR ~3.3 vs ~1.35 for dabrafenib (Sanagawa 2021; Jhaveri 2015). If a BRAF inhibitor is needed and kidney risk is a concern, dabrafenib carries a substantially lower renal signal.
  • Adding a MEK inhibitor (cobimetinib) is not just about efficacy: it cut AKI incidence roughly 60% versus vemurafenib monotherapy (Teuma 2017).
  • Injury is early and usually low-grade and reversible on hold, but severe episodes can leave persistent CKD — don't dismiss a creatinine bump in the first three months.
  • Renal excretion is trivial (~1%), so there is no pharmacokinetic reason to renally dose-adjust — dose modification is driven by the toxicity itself.
  • Electrolyte wasting (hypokalemia, hyponatremia, hypophosphatemia) and glycosuria are clues that the proximal tubule, not the glomerulus, is the target.
  • The unexplained male predominance of vemurafenib AKI is a genuine, reproducible pharmacovigilance finding, not a sampling artifact.

Anticancer mechanism

Oral small-molecule, ATP-competitive inhibitor of mutated BRAF kinase (V600E/V600K). By shutting down constitutively active RAF-MEK-ERK (MAPK) signaling in BRAF V600-mutant melanoma cells, it drives cell-cycle arrest and apoptosis. In BRAF wild-type cells it paradoxically activates ERK through CRAF, the mechanistic basis for its cutaneous squamous proliferations (and part of the rationale for co-administering a downstream MEK inhibitor).

Note

Nephrotoxicity was not recognized in the pivotal registrational program and emerged only through post-marketing case series and FAERS pharmacovigilance. Much of the incidence evidence is combination (vemurafenib+cobimetinib) or spontaneous-report data, so quantitative estimates should be read as directional rather than precise.

Guidelines & consensus

  • 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 (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

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

  1. 1.Nephrotoxicity of the BRAF Inhibitors Vemurafenib and Dabrafenib.Jhaveri KD et al. · JAMA Oncol · 2015 · PMID 26182194
  2. 2.Acute renal failure associated with the new BRAF inhibitor vemurafenib: a case series of 8 patients.Launay-Vacher V et al. · Cancer · 2014 · PMID 24737576
  3. 3.BRAF/MEK inhibitor-associated nephrotoxicity in a real-world setting and human kidney cells.Sanagawa A et al. · Anticancer Drugs · 2021 · PMID 34232935
  4. 4.Adjunction of a MEK inhibitor to Vemurafenib in the treatment of metastatic melanoma results in a 60% reduction of acute kidney injury.Teuma C et al. · Cancer Chemother Pharmacol · 2017 · PMID 28396940
  5. 5.BRAF inhibitors - do we need to worry about kidney injury?Wanchoo R et al. · Expert Opin Drug Saf · 2016 · PMID 26954036
  6. 6.Improved survival with vemurafenib in melanoma with BRAF V600E mutation.Chapman PB et al. · N Engl J Med · 2011 · PMID 21639808
Educational monograph from NephTox (nephtox.com). Not medical advice — verify against current guidelines before any clinical decision.