What kind of kidney injury does Erdafitinib cause?

Electrolyte Disturbance — Renal electrolyte derangement — magnesium/potassium/calcium wasting (cisplatin, anti-EGFR antibodies) or retention (FGFR-inhibitor hyperphosphatemia, tumor-lysis hyperkalemia/hyperphosphatemia).

How should kidney function be monitored during Erdafitinib therapy?

Serum phosphate at baseline and every 2-3 weeks early (then monthly) to drive dose titration; Serum calcium and calcium-phosphate product; Ophthalmologic exams for central serous retinopathy; routine creatinine.

How can kidney injury from Erdafitinib be prevented?

Serum phosphate monitoring with protocol-based dose titration Low-phosphate diet (~600-800 mg/day) when phosphate rises Avoid phosphate-containing supplements/laxatives

Who is at higher risk of kidney injury from Erdafitinib?

Higher dose / up-titration to 9 mg; Pre-existing CKD; High dietary phosphate or phosphate supplements.

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Printable monograph

FGFR inhibitor

Erdafitinib

Balversa · Erda

FGFR inhibitor · approved 2019 · 7 citations

Recent· through 2024

Fairly sourced5/9 · 5 signals

Met: 7 citations
Not met: 12+ references
Not met: Accrued over 10+ years (span: 7y)
Met: Beyond single case reports
Met: High-impact journal
Met: Landmark reference
Met: Current through 2024
Not met: Real-world FAERS signal

Describes how this page is sourced, not how dangerous the drug is. Thinly sourced means fewer of the sourcing signals are met — not that the agent is kidney-safe. A rule-based summary, not a formal certainty appraisal.

The first FGFR inhibitor in urothelial cancer — on-target FGFR1 blockade drives hyperphosphatemia.

ModerateFGFR inhibitor

FGFR2/3-altered locally advanced or metastatic urothelial carcinoma

§01

Signature kidney injury

Signature lesion

Electrolyte Disturbance

Representative incidence73%

73–78% range across studies

Hyperphosphatemia is the most common, on-target class adverse event — reported in ~73-78% of treated patients across studies and used as a pharmacodynamic marker for protocol-driven dose up-titration. Grade >=3 hyperphosphatemia is much less frequent (~2%).Source: Nishina et al., Invest New Drugs 2017

Onset & rechallenge

Time to injurySubacute (~1–6 weeks)

Early — typically within the first 1–2 cycles (on-target hyperphosphatemia used to guide up-titration).

Distilled from: “Early — typically within the first 1-2 cycles, used to guide pharmacodynamic up-titration.”

§02

Renal toxicities, ranked

This agent's defining kidney lesion — its #1 signature. Cited incidence is shown where a citable figure exists; otherwise the tier stands qualitatively.

Electrolyte Disturbance#1 · Signaturequalitative — no citable incidence
Renal electrolyte derangement — magnesium/potassium/calcium wasting (cisplatin, anti-EGFR antibodies) or retention (FGFR-inhibitor hyperphosphatemia, tumor-lysis hyperkalemia/hyperphosphatemia).

§03

Kidney injury

Mechanism of kidney injury

FGFR1 inhibition disrupts the FGF23-Klotho-FGFR1 axis that normally suppresses proximal-tubular phosphate reabsorption (by down-regulating the NaPi-2a/2c cotransporters) and inhibits 1-alpha-hydroxylase. Blocking this signaling increases tubular phosphate reabsorption and raises serum phosphate; sustained hyperphosphatemia with a high calcium-phosphate product risks soft-tissue and vascular calcification (including calcinosis cutis) and nephrocalcinosis.

Clinical presentation

Asymptomatic hyperphosphatemia detected on routine labs, often within the first 2-3 weeks; may be accompanied by an elevated calcium-phosphate product. Severe/persistent cases risk metastatic mineral deposition; non-renal effects (stomatitis, nail and skin changes, central serous retinopathy) are common.

Management

Per label: if phosphate exceeds ~5.5 mg/dL, restrict dietary phosphate and start an oral phosphate binder (e.g. sevelamer); for higher thresholds (~7-10 mg/dL or symptoms) interrupt and dose-reduce, and discontinue for persistent levels >10 mg/dL despite intervention. Up-titrate the dose at day 14-21 only if phosphate is <5.5 mg/dL and no significant toxicity.Lesion-level management framework

Risk factors

Higher dose / up-titration to 9 mg
Pre-existing CKD
High dietary phosphate or phosphate supplements

Prevention

Serum phosphate monitoring with protocol-based dose titration
Low-phosphate diet (~600-800 mg/day) when phosphate rises
Avoid phosphate-containing supplements/laxatives

Anticancer mechanism· how it treats cancer

Oral pan-FGFR (FGFR1-4) tyrosine kinase inhibitor; blocks oncogenic FGFR signaling in FGFR-altered tumors. Approved for FGFR2/3-altered locally advanced or metastatic urothelial carcinoma.

§04

Clinical depth

Renal dose adjustment

No starting-dose change for mild-moderate renal impairment; severe impairment and dialysis are not well studied (use with caution). The principal 'dose adjustment' is phosphate-guided titration/interruption rather than a CrCl-based rule.

Dialyzability & ESKD dosing

Highly protein-bound oral small molecule; not expected to be appreciably dialyzed. No validated ESKD dosing — phosphate handling is also altered in ESKD, complicating the pharmacodynamic phosphate biomarker.

Differential diagnosis

FGFR-inhibitor hyperphosphatemia (on-target, early, isolated, dose-related) vs hyperphosphatemia of CKD/ESKD, tumor lysis (accompanied by hyperuricemia/hyperkalemia and AKI), or exogenous phosphate load. The temporal link to dosing and use as a PD marker are characteristic.

Monitoring

Serum phosphate at baseline and every 2-3 weeks early (then monthly) to drive dose titration
Serum calcium and calcium-phosphate product
Ophthalmologic exams for central serous retinopathy; routine creatinine

Key trials & series

BLC2001 (registrational FGFR-altered urothelial carcinoma)
THOR (erdafitinib vs chemotherapy/pembrolizumab in urothelial carcinoma)
RAGNAR (tumor-agnostic FGFR-altered solid tumors)
Siefker-Radtke 2023 BLC2001 TEAE-management analysis

Clinical pearls

Hyperphosphatemia here is an expected on-target FGFR1 effect and a dosing biomarker — not idiosyncratic toxicity — and is actually used to confirm adequate target engagement before up-titration.
Manage with diet and binders first; reserve dose interruption/reduction for higher thresholds.
Sustained high calcium-phosphate product can cause calcinosis cutis and nephrocalcinosis — keep the product down, not just the phosphate.

Where it strikes· nephron segments & injury signatures

Nephron segments

Proximal Tubule

Bulk reabsorption + drug uptake (OCT2, OATs)

Injury signatures

Electrolyte Disturbance

Beyond the kidney — non-renal toxicities· 2 organ systems

Class-level context for the major non-renal toxicities of the FGFR inhibitor class.

Ophthalmic

Keratopathy, uveitis, retinopathy

Central serous retinopathy

Dermatologic

Rash, HFS, SJS/TEN, vitiligo

Nail/skin changes, hand-foot syndrome

§05

References

7 primary references — trials, cohorts, mechanism, and reviews. Citation metadata via PubMed / NLM.

Evidence accrual

7 references · 2017–2024 · 4 since 2022

Primary (non–case-report) references per year — a proxy for how actively the agent's renal literature is accruing. Recent years are highlighted. Reflects curation depth, not a systematic bibliometric count.

What gets reported — FAERS

Everything below is FAERS — adverse events someone chose to report, about 1,215 of them for this agent. Nobody counts the patients who were fine, so none of these numbers is an incidence, a risk, or a rate: they describe what gets reported, shaped by a drug's fame, its indication, and who was watching. How these numbers work.

Reporting odds ratio (ROR) — is kidney injury named in this agent's reports more often than in every other drug's? Above 1 means yes, disproportionately.
Renal phenotypes — the same question asked separately for each kind of kidney injury, so the ratios differ from the overall one and from each other.
Outcomes — a share of this agent's own reports, not of patients: how many were filed as involving a death or a hospitalization. Not a case-fatality rate.

FAERS reported renal phenotypes· 2 signals

Only significant signals appear (95% CI lower bound above 1) — a phenotype missing here was tested and did not reach significance, except Prerenal / Hemodynamic AKI, Pseudo-AKI, Renal Cysts, Chronic Interstitial Nephropathy — outside the clinician-reviewed MedDRA term map, never queried — and ATN and AIN, queried but biopsy-bound: real cases are filed as generic “acute kidney injury”, so their absence is not a negative. As of 2026-10-01.

What reporting says about this profile's documented lesions

Electrolyte Disturbancecorroborated · ROR 1.73 — but the naming terms alone are not disproportionate, so this rests on terms merely consistent with the lesion

SIADH / Hyponatremia

ROR 2.5995% CI 1.47–4.57· 12 reports

Electrolyte Disturbance

ROR 1.7395% CI 1.10–2.72· 19 reports

FAERS outcomes & reporting trend· 28.1% of reports w/ death · 21.1% w/ hospitalization

28.1%

Reported with a death outcome

342 of 1,215 reports

21.1%

Reported with hospitalization

256 of 1,215 reports

Reports per year

Yearly FAERS report volume · most recent year is partial.

FAERS adverse-event signal — all organ systems· 7 systems · 1,215 reports

Bars rank systems by summed reaction-term mentions (a report counts once per term it names) — an ordinal “more vs less reported” cue, not a tally of distinct reports. Renal & urinary first. As of 2026-10-01.

Disproportionality (acute kidney injury):ROR 1.1395% CI 0.61–2.11· 10 AKI reports ·no disproportionate AKI reporting signal (CI spans 1).

Gastrointestinal

Diarrhoea97Stomatitis77Dry Mouth46Mucosal Inflammation38Nausea28

Skin

Nail Disorder52Nail Discolouration43Dry Skin31Alopecia27Palmar-Plantar Erythrodysaesthesia Syndrome26

General / constitutional

Fatigue53Weight Decreased27Asthenia24

Eye

Dry Eye41Eye Disorder29Cataract26

Metabolic & electrolyte

Hyperphosphataemia51Decreased Appetite37

Musculoskeletal

Pain In Extremity34

Nervous system

Taste Disorder30

Guidelines & consensus· 13

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.

General onco-nephrology references

ADQIThe nephrotoxic effects of anti-cancer therapies: consensus report of the 34th Acute Disease Quality Initiative workgroupNat Rev Nephrol 2026 · PMID 41361704Provides 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.SIRMSIRM-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)Radiol Med 2022 · PMID 35303246Recommends 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.KDIGOKDIGO Controversies Conference on onco-nephrology: understanding kidney impairment and solid-organ malignancies, and managing kidney cancerKidney Int 2020 · PMID 33126977Identifies 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.KDIGOKDIGO Controversies Conference on onco-nephrology: kidney disease in hematological malignancies and the burden of cancer after kidney transplantationKidney Int 2020 · PMID 33276867Addresses 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.ADDIKDIntegrating International Consensus Guidelines for Anticancer Drug Dosing in Kidney Dysfunction (ADDIKD) into everyday practiceEClinicalMedicine 2025 · PMID 40290844Provides 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.ADDIKDAligning kidney function assessment in patients with cancer to global practices in internal medicineEClinicalMedicine 2025 · PMID 40290845Three 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.ADDIKDA methodology for determining dosing recommendations for anticancer drugs in patients with reduced kidney functionEClinicalMedicine 2025 · PMID 40290846Establishes 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.KDIGODiagnosis, evaluation, and management of acute kidney injury: a KDIGO summary (Part 1)Crit Care 2013 · PMID 23394211Defines/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.KDIGOExecutive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknownsKidney Int 2024 · PMID 38519239Evaluate 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.KDIGOExecutive summary of the KDIGO 2021 Guideline for the Management of Glomerular DiseasesKidney Int 2021 · PMID 34556300Provides 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.KDIGOExecutive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of ANCA-Associated VasculitisKidney Int 2024 · PMID 38388147Updates 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.KDIGOExecutive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of Lupus NephritisKidney Int 2024 · PMID 38182299Updates 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.KDIGOExecutive summary of the KDIGO 2025 Clinical Practice Guideline for the Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV)Kidney Int 2025 · PMID 40975525Encourages 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.

Where Erdafitinib sits in nephrotoxicity space — each dot is an anti-cancer agent, positioned so neighbors share a kidney-injury phenotype. Its 6 closest are filled and lead to a numbered marker, matching the numbered cards below.

Position is a 2-D projection (MDS) of each agent's injury signature, nephron target, severity, and class, so two dots can sit close on the page while differing on an axis the projection flattened — the numbered ranking is computed from the full metric, not from the distance you see. Open the full map.

Phenotype-similar agents· the numbered markers on the map above

Futibatinib

Lytgobi · FGFR inhibitor

Profile

Hyperphosphatemia, class effect.

LYTE

Moderate#1 · 100% phenotype match

Pemigatinib

Pemazyre · FGFR inhibitor

Profile

Hyperphosphatemia; nephrocalcinosis risk.

LYTE

Moderate#2 · 100% phenotype match

Infigratinib

Truseltiq · FGFR inhibitor

Profile

Hyperphosphatemia — on-target FGFR class effect; nephrocalcinosis risk.

LYTEXTAL

Moderate#3 · 73% phenotype match

Denosumab

Xgeva · Anti-RANKL antibody

Profile

Severe hypocalcemia in low GFR; not directly nephrotoxic.

LYTE

Moderate#4 · 66% phenotype match

Necitumumab

Portrazza · Anti-EGFR antibody

Profile

Severe hypomagnesemia, class effect.

LYTE

Moderate#5 · 66% phenotype match

Nedaplatin

Aqupla · Platinum agent

Profile

Second-gen platinum with reduced renal toxicity vs cisplatin.

ATNLYTE

Moderate#6 · 65% phenotype match

Compare Erdafitinib with its nearest agents

Nearest agents by kidney-injury phenotype (shared injuries, nephron target, severity, class) — a similarity approximation, not a claim of shared drug identity or mechanism.

Kidney risk across FGFR inhibitors

Same-class agents ordered by their documented kidney-injury profile — atlas severity, an acute-kidney-injury FAERS signal, and how many injury types each is documented to cause. Agents nearer the top carry the lighter documented renal profile.

1Erdafitinib· this agentLYTE — Electrolyte DisturbanceModerate
2FutibatinibLYTE — Electrolyte DisturbanceModerate
3PemigatinibLYTE — Electrolyte DisturbanceModerate
4InfigratinibLYTE — Electrolyte DisturbanceModerate

A comparison of documented kidney-injury data within one drug class — not a substitution recommendation. Efficacy, indication, and non-renal toxicity differ between these agents and are out of scope here. Educational only, not medical advice.