Cyclophosphamide
Cytoxan · Oxazaphosphorine alkylator
Vasopressin-independent hyponatremia; hemorrhagic cystitis.
SIADHCYST
MildOpen →
EGFR exon20 TKI
Sunvozertinib
Zegfrovy · SUNV
An EGFR exon-20 TKI whose renal story is electrolyte wasting more than structural injury.
MildEGFR exon-20 TKI · approved 2025
EGFR exon-20 insertion non-small cell lung cancer
Signature kidney injury
SIADH / Hyponatremia
No established AKI rate. As with the EGFR-inhibitor class, the renal-relevant signal is electrolyte disturbance — particularly hypomagnesemia (renal Mg wasting) and diarrhea-driven losses, with a hyponatremia/SIADH-like pattern possible — rather than structural nephron injury. WU-KONG6 reported diarrhea and skin/EGFR-pathway toxicities as dominant; renal-specific events are not quantified.
Source: Wang M et al., Lancet Respir Med 2023
Toxicity fingerprint
Tap a signature to trace where it strikes the nephron.
Incidence not quantified
SeverityMild
ReversibilityReversible
Evidence0 refs
Nephron map
Vasculature / Endothelium
Distal Tubule / Collecting DuctFine-tuning of Na, K, Mg, acid & water
SIADH / Hyponatremia
Inappropriate water retention at the collecting duct — high-dose cyclophosphamide.
Mechanism of kidney injury
EGFR is constitutively expressed in the distal convoluted tubule, where it sustains the magnesium channel TRPM6; EGFR blockade produces a TRPM6-dependent renal magnesium- (and calcium-) wasting state with hypomagnesemia and secondary hypokalemia. Class effects on distal/collecting-duct water handling can yield a euvolemic, SIADH-like hyponatremia, and diarrhea adds GI electrolyte loss and prerenal volume depletion. Direct tubular necrosis is not a described feature.
Clinical presentation
Hypomagnesemia (often the earliest finding) with hypocalcemia and hypokalemia; euvolemic, SIADH-pattern hyponatremia in some; diarrhea-related volume depletion; bland urinalysis; creatinine usually stable unless volume-depleted. Symptoms of Mg deficiency can be subtle (fatigue, cramps) or serious (arrhythmia, seizure).
Onset
Electrolyte changes can appear within the first weeks to months of therapy; hypomagnesemia risk rises with treatment duration.
Reversibility
Reversible
Anticancer mechanism
Oral irreversible EGFR tyrosine kinase inhibitor with activity against EGFR exon-20 insertion mutations (and selected other EGFR mutations) while relatively sparing wild-type EGFR. Approved for previously treated locally advanced/metastatic NSCLC with EGFR exon-20 insertions.
Management
Correct electrolytes (replete magnesium — often parenterally as oral Mg is poorly absorbed and causes diarrhea; correct hypocalcemia/hypokalemia after Mg; manage sodium per SIADH principles with fluid restriction as appropriate), control diarrhea, and ensure euvolemia. Dose interrupt/reduce per protocol for severe toxicity. No structural renal lesion to treat.
Risk factors
- Concurrent diuretics or other SIADH-inducing/Mg-wasting drugs
- Significant treatment-related diarrhea
- Baseline electrolyte abnormalities or CKD
- Longer treatment duration (cumulative Mg wasting)
Prevention
- Monitor magnesium, calcium, sodium and potassium regularly
- Aggressive diarrhea management and hydration
- Review concomitant medications that promote hyponatremia or Mg wasting
Note · 2025 approval (initially via WU-KONG6 in China; subsequent US accelerated approval). Renal data are essentially absent; the SIADH/electrolyte framing is conservative EGFR-inhibitor-class reasoning, anchored to the well-established TRPM6 magnesium-wasting mechanism.
Clinical depth
Renal dose adjustment
No dedicated renal dose adjustment established; sunvozertinib is hepatically metabolized (CYP3A) with low renal clearance, so mild-moderate impairment is not expected to require change. Limited data in severe impairment/dialysis.
Dialyzability & ESKD dosing
Not characterized; a highly protein-bound, non-renally cleared small molecule is unlikely to be appreciably dialyzed. No ESKD dosing guidance.
Differential diagnosis
Refractory hypokalemia/hypocalcemia that won't correct until magnesium is repleted points to EGFR-inhibitor TRPM6 Mg wasting. Distinguish SIADH-pattern hyponatremia (euvolemic, concentrated urine) from prerenal hyponatremia of diarrhea/volume depletion.
Monitoring
- Serum magnesium, calcium, potassium and sodium each cycle (and with symptoms)
- Stool frequency and volume status
- Creatinine periodically
Key trials & series
- WU-KONG6 (Wang, Lancet Respir Med 2023) — pivotal phase 2 carrying the safety signal
Clinical pearls
- EGFR inhibition wastes magnesium via TRPM6 in the distal tubule — check Mg, and replete it first, as hypokalemia/hypocalcemia are refractory until Mg is corrected.
- Oral Mg often worsens diarrhea; IV repletion is frequently needed.
- The renal story is electrolytes, not creatinine — the kidney is structurally intact.
Where it strikes
Nephron segments
Distal Tubule / Collecting Duct
Fine-tuning of Na, K, Mg, acid & water
Injury signatures
SIADH / HyponatremiaElectrolyte WastingPrerenal / Hemodynamic AKI
Beyond the kidney
Class-level context for the major non-renal toxicities of egfr exon20 tkis.
Dermatologic
Rash, HFS, SJS/TEN, vitiligo
- Acneiform rash, paronychia
Gastrointestinal
Diarrhea, colitis, mucositis, perforation
- Diarrhea
Pulmonary
Pneumonitis, ILD, effusions, hypertension
- Interstitial lung disease (EGFR TKIs)
Evidence
4 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkSunvozertinib for patients in China with platinum-pretreated locally advanced or metastatic non-small-cell lung cancer and EGFR exon 20 insertion mutation (WU-KONG6): single-arm, open-label, multicentre, phase 2 trial.Wang M et al. · Lancet Respir Med 2023 · PMID 38101437Pivotal trial; diarrhea and EGFR-pathway toxicities dominate, supporting the electrolyte/SIADH-focused renal framing.LandmarkHypomagnesaemia and targeted anti-epidermal growth factor receptor (EGFR) agents.Costa A et al. · Target Oncol 2011 · PMID 22113391Defines the EGFR/TRPM6 renal magnesium-wasting mechanism — the mechanistic basis for the electrolyte signature of this class.PMIDNew drug toxicities in the onco-nephrology world.Perazella MA et al. · Kidney Int 2015 · PMID 25671763Onconephrology review of targeted-agent electrolyte disturbances (including EGFR-related hypomagnesemia) and AKI patterns.PMIDOnconephrology: mitigation of renal injury in chemotherapy administration.Selamet U et al. · Curr Opin Nephrol Hypertens 2023 · PMID 38095483Onconephrology review of tyrosine-kinase-inhibitor renal and electrolyte effects and monitoring.