Bendamustine
Treanda · Alkylator
Tumor lysis-mediated AKI is the principal risk; TMA is rare.
PRETMALYTE
ModerateOpen →
HER2 bispecific antibody
Zanidatamab
Ziihera · ZANI
A biparatopic HER2 bispecific that clamps two HER2 epitopes at once — with a kidney signal that is, so far, mostly indirect.
MildHER2 bispecific antibody · approved 2024
HER2-positive biliary tract cancer (cholangiocarcinoma, gallbladder cancer)
Signature kidney injury
Prerenal / Hemodynamic AKI
No drug-specific nephrotoxicity rate is established. In HERIZON-BTC-01 the dominant toxicities were diarrhea and infusion reactions; any AKI is expected to be largely prerenal/volume-mediated (diarrhea, reduced intake) or related to the underlying biliary obstruction, rather than a direct tubular effect.
Source: Harding et al., Lancet Oncol 2023
Mechanism of kidney injury
No established direct nephron injury. HER2 is not a major renal tubular antigen, so antibody-mediated tubular toxicity is not expected. The plausible pathway is prerenal/hemodynamic: GI losses from diarrhea and infusion-related volume shifts reducing effective renal perfusion. In cholangiocarcinoma/gallbladder cancer, post-renal obstructive AKI from biliary/ureteric compression and sepsis-associated ischemic injury are competing, often dominant, causes.
Clinical presentation
When present, a modest reversible creatinine rise in the setting of diarrhea/volume depletion; bland urinalysis; electrolyte derangements (hypokalemia, hypomagnesemia) tracking GI losses rather than a primary tubulopathy. A rising creatinine with hydronephrosis on imaging should prompt evaluation for obstruction rather than drug toxicity.
Onset
Variable; tied to GI/volume events during treatment cycles rather than a fixed latency.
Reversibility
Reversible
Anticancer mechanism
Humanized bispecific antibody binding two non-overlapping (biparatopic) epitopes of the HER2 ectodomain (ECD2 and ECD4), driving receptor clustering, internalization and downregulation, plus complement-dependent and antibody-dependent cellular cytotoxicity. Approved for HER2-amplified (IHC 3+) previously treated unresectable/metastatic biliary-tract cancer.
Management
Largely supportive: rehydrate, control diarrhea, replace electrolytes, and hold for severe volume-mediated AKI. True intrinsic renal injury has not been characterized; evaluate for alternative causes (obstruction, sepsis, contrast, concomitant chemotherapy) before drug attribution.
Risk factors
- Treatment-related diarrhea and poor oral intake
- Baseline CKD or volume depletion
- Concurrent nephrotoxins or diuretics
- Biliary/ureteric obstruction and sepsis in cholangiocarcinoma
Prevention
- Aggressive antidiarrheal management and hydration
- Monitor creatinine and electrolytes each cycle
- Correct volume status and exclude obstruction before attributing AKI to the drug
Note · 2024 approval with essentially no renal-specific literature. The prerenal/vascular signature is inferred from the GI-dominant toxicity profile and class reasoning, not from published nephrology data. Treat all renal claims as provisional.
Clinical depth
Renal dose adjustment
No dedicated renal dose adjustment is specified; as a ~150 kDa monoclonal-type bispecific, clearance is not renal and exposure is not expected to change meaningfully with reduced GFR. No data in dialysis. Manage by holding/resuming for toxicity rather than CrCl-based reduction.
Dialyzability & ESKD dosing
Not dialyzable — large bispecific antibody cleared by reticuloendothelial proteolysis, not removed by hemodialysis or peritoneal dialysis. No ESKD-specific dosing guidance exists; standard dosing is reasonable with attention to volume status during infusion.
Differential diagnosis
Distinguish prerenal/diarrhea-driven AKI (low FeNa, responds to volume) from post-renal obstruction (hydronephrosis on ultrasound — common in biliary cancer) and from sepsis-associated ATN. The drug itself is rarely the primary cause.
Monitoring
- Serum creatinine and electrolytes (K, Mg) each cycle
- Stool frequency/volume and weight as surrogates for volume status
- Imaging review for biliary/ureteric obstruction if creatinine rises
- LVEF per label (HER2-directed cardiac monitoring)
Key trials & series
- HERIZON-BTC-01 (Harding, Lancet Oncol 2023) — pivotal phase 2b carrying the safety signal
- Real-world biliary-tract cohort (Smolenschi, Eur J Cancer 2025)
Clinical pearls
- In biliary-tract cancer, think obstruction and sepsis first — antibody-mediated tubular injury is not an expected mechanism.
- Electrolyte loss here is GI, not tubular: replace and treat the diarrhea.
- Renal claims for this 2024 agent are provisional and class-based, not evidence from nephrology cohorts.
Where it strikes
Nephron segments
Vasculature / Endothelium
Glomerular & peritubular capillaries
Injury signatures
Prerenal / Hemodynamic AKIElectrolyte Wasting
Beyond the kidney
Class-level context for the major non-renal toxicities of her2 bispecific antibodys.
Immune / Infusion
CRS, infusion reactions, irAEs, anaphylaxis
- Cytokine release syndrome
Neurologic
Neuropathy, encephalopathy, ICANS, PRES
- ICANS / neurotoxicity
Hematologic
Cytopenias, thrombosis, TMA
- Cytopenias, hypogammaglobulinemia
Evidence
5 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkZanidatamab for HER2-amplified, unresectable, locally advanced or metastatic biliary tract cancer (HERIZON-BTC-01): a multicentre, single-arm, phase 2b study.Harding JJ et al. · Lancet Oncol 2023 · PMID 37276871Pivotal trial; safety profile is GI-dominant (diarrhea, infusion reactions) with no signal of direct nephrotoxicity — basis for the prerenal/indirect framing.PMIDReal-world efficacy of zanidatamab in patients with HER2 positive advanced biliary tract cancers.Smolenschi C et al. · Eur J Cancer 2025 · PMID 40319675Real-world series corroborating the tolerability profile in advanced biliary-tract cancer.PMIDOnconephrology: mitigation of renal injury in chemotherapy administration.Selamet U et al. · Curr Opin Nephrol Hypertens 2023 · PMID 38095483Onconephrology review of biologic-agent renal effects, framing antibody-class agents as low-risk for direct tubular injury.PMIDNew drug toxicities in the onco-nephrology world.Perazella MA et al. · Kidney Int 2015 · PMID 25671763Foundational onconephrology review of targeted-agent nephrotoxicity patterns (AKI, electrolyte disturbance, proteinuria) used to frame class expectations.PMIDAcute Kidney Injury in Patients With Cancer: A Review of Onconephrology.Gudsoorkar P et al. · Adv Chronic Kidney Dis 2021 · PMID 35190106General onconephrology review covering prerenal/obstructive AKI mechanisms relevant to GI-cancer therapy.
Related agents
Other agents sharing the same signature kidney injury.