Cyclophosphamide
Cytoxan · Oxazaphosphorine alkylator
Vasopressin-independent hyponatremia; hemorrhagic cystitis.
SIADHCYST
MildOpen →
EGFR TKI (3rd-gen)
Lazertinib
Lazcluze · Lazer
A third-generation EGFR TKI — hyponatremia and EGFR-class electrolyte wasting.
MildThird-generation EGFR TKI · approved 2024
EGFR-mutant advanced NSCLC (with amivantamab)
Signature kidney injury
SIADH / Hyponatremia
Hyponatremia is a recognized signal of third-generation EGFR TKIs (an osimertinib-class effect); for lazertinib specifically the renal/sodium data are limited and not well quantified. EGFR blockade also causes electrolyte wasting (hypomagnesemia, hypokalemia), and combination with amivantamab adds to these effects.
Source: Felip et al., Ann Oncol 2024 (MARIPOSA)
Mechanism of kidney injury
Two EGFR-pathway mechanisms touch the kidney. (1) Like other third-generation EGFR TKIs, lazertinib is associated with hyponatremia, postulated to reflect SIADH-type dysregulation of water handling at the distal nephron/collecting duct (euvolemic, dilutional). (2) EGFR signaling sustains the distal-tubular magnesium channel TRPM6, so EGFR inhibition can cause renal magnesium (and potassium/calcium) wasting. Direct tubular toxicity is not characteristic; the renal footprint is water/electrolyte dysregulation.
Clinical presentation
Euvolemic hyponatremia — low serum sodium with low serum osmolality and inappropriately concentrated urine — when SIADH-type; hypomagnesemia/hypokalemia, especially in combination therapy. Serum creatinine is usually stable.
Onset
During therapy; case-level and variable.
Reversibility
Reversible
Anticancer mechanism
Third-generation, CNS-penetrant, irreversible EGFR tyrosine-kinase inhibitor selective for EGFR-activating (exon 19 deletion, L858R) and T790M resistance mutations while sparing wild-type EGFR. Approved with amivantamab for first-line EGFR-mutant advanced NSCLC.
Management
For SIADH-type hyponatremia: fluid restriction, remove contributing drugs, correct sodium at a safe rate (<8–10 mEq/L per 24 h to avoid osmotic demyelination); consider drug hold for severe/symptomatic hyponatremia. Replete magnesium/potassium for EGFR-class wasting.
Risk factors
- Concurrent SIADH-promoting drugs
- Combination with amivantamab (overlapping EGFR-class effects)
- Volume-status changes
- Older age
Prevention
- Monitor serum sodium (and magnesium/potassium in combination)
- Evaluate for SIADH if hyponatremia develops
- Review and address other ADH-promoting medications
- Replete magnesium proactively
Note · Hyponatremia is extrapolated from the third-generation EGFR-TKI (osimertinib) class; lazertinib-specific renal literature is thin. The EGFR-class electrolyte (magnesium) wasting is the more mechanistically grounded effect and overlaps with amivantamab when combined.
Clinical depth
Renal dose adjustment
No established renal dose adjustment (not renally cleared to a significant degree); severe impairment/ESKD not well studied. Manage by sodium/electrolyte correction and drug hold for severe hyponatremia rather than GFR-based dosing.
Dialyzability & ESKD dosing
Highly protein-bound, hepatically metabolized small molecule; not expected to be appreciably dialyzed. No specific ESKD dosing — focus on sodium and electrolyte management.
Differential diagnosis
SIADH-type euvolemic hyponatremia vs hypovolemic (poor intake, GI losses) vs other-drug SIADH (urine sodium/osmolality with volume assessment); EGFR-class hypomagnesemia (low Mg with renal wasting) is distinct from the hyponatremia and may coexist, particularly in combination with amivantamab.
Monitoring
- Serum sodium periodically and whenever symptoms suggest hyponatremia
- Serum magnesium, potassium and calcium (especially with amivantamab)
- Creatinine each cycle
- Volume status assessment if hyponatremic
Key trials & series
- MARIPOSA (Felip Ann Oncol 2024) lazertinib + amivantamab vs osimertinib
- LASER301 (lazertinib monotherapy registrational)
Clinical pearls
- Check sodium: third-generation EGFR TKIs carry an osimertinib-class hyponatremia (SIADH-type) signal — treat with water restriction, not saline alone.
- EGFR blockade also wastes magnesium via TRPM6 — replete proactively, especially when combined with amivantamab.
- Correct hyponatremia slowly (<8–10 mEq/L/24 h) to avoid osmotic demyelination.
- Creatinine usually stays put; the renal story here is water and electrolytes.
Where it strikes
Nephron segments
Distal Tubule / Collecting Duct
Fine-tuning of Na, K, Mg, acid & water
Injury signatures
SIADH / HyponatremiaElectrolyte Wasting
Beyond the kidney
Class-level context for the major non-renal toxicities of egfr tki (3rd-gen)s.
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
6 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkAmivantamab plus lazertinib versus osimertinib in first-line EGFR-mutant advanced non-small-cell lung cancer with biomarkers of high-risk disease: a secondary analysis from MARIPOSA.Felip E et al. · Ann Oncol 2024 · PMID 38942080Registrational combination context and comparative safety vs osimertinib.PMIDAdverse kidney effects of epidermal growth factor receptor inhibitors.Izzedine H et al. · Nephrol Dial Transplant 2017 · PMID 28339780Onconephrology review of EGFR-inhibitor electrolyte (magnesium) wasting and tubular effects underpinning lazertinib's class renal profile.PMIDHypomagnesaemia and targeted anti-epidermal growth factor receptor (EGFR) agents.Costa A et al. · Target Oncol 2011 · PMID 22113391Mechanism of EGFR-blockade renal magnesium wasting via TRPM6 — the basis for lazertinib electrolyte effects.PMIDManagement of euvolemic hyponatremia attributed to SIADH in the hospital setting.Peri A et al. · Minerva Endocrinol 2014 · PMID 24513602SIADH-type euvolemic hyponatremia management (fluid restriction, vaptans) directly relevant to the EGFR-TKI hyponatremia signal.PMIDHyponatremia: classification and differential diagnosis.Marco Martinez J et al. · Endocrinol Nutr 2010 · PMID 21130956Differential of euvolemic/SIADH-type vs other hyponatremia — supports diagnostic workup of the EGFR-TKI sodium signal.PMIDThe changing treatment landscape of EGFR-mutant non-small-cell lung cancer.Zhou F et al. · Nat Rev Clin Oncol 2024 · PMID 39614090Review of third-generation EGFR TKIs (including lazertinib) and their class profile.