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Purine analog

Clofarabine

Clolar · Clofar

Purine analog · approved 2004 · 8 references

A second-generation purine analog whose systemic inflammatory storm can starve the kidney of perfusion.

Signature injury
Prerenal / Hemodynamic AKI
Severity
Moderate
Reversibility
Partially reversible
Onset
Early, typically within the first treatment cycle (days).

Signature kidney injury & incidence

Prerenal / Hemodynamic AKI — representative incidence ~6%.

A systemic inflammatory response syndrome (SIRS) / capillary-leak syndrome with associated AKI was reported in roughly 4% of treated children in the registration program; hypotension was among the most common grade 3 or greater adverse events in the pivotal phase II trial. Precise renal incidence is not well quantified and most AKI data are case-level. Reported rate: renal insufficiency in 6% — Adults with relapsed and/or refractory non-Hodgkin lymphoma receiving SINGLE-AGENT clofarabine (1-h IV daily x5, q28d)… (Nabhan 2011, PMID 21425150).

Source: Nabhan et al., Cancer 2011

Reported injury signatures: Prerenal / Hemodynamic AKI, Acute Tubular Necrosis, Glomerular Injury / Proteinuria, Crystal / Obstructive Nephropathy.

Renal toxicity profile

  1. Prerenal / Hemodynamic AKIPrimary
  2. Acute Tubular NecrosisSecondarySevere acute tubular injury described as a dominant AKI mechanism in a clinicopathologic report plus a FAERS review of 29 additional renal adverse-event cases
  3. Glomerular Injury / ProteinuriaRareCollapsing glomerulopathy with heavy proteinuria reported at case level
  4. Crystal / Obstructive NephropathyRare

Onset timing & rechallenge

Acute (~1–7 days) — Early — typically within the first treatment cycle (days).

Mechanism of kidney injury

The dominant lesion is hemodynamic. Drug-induced cytokine release (a SIRS / capillary-leak physiology, sometimes overlapping with a cytokine-release-like state during rapid cytoreduction) drives systemic vasodilation, third-spacing and intravascular volume depletion, producing prerenal AKI that can progress to ischemic acute tubular necrosis when hypotension is sustained. Concurrent tumor lysis at treatment initiation adds intratubular urate/phosphate load. Case-level and preclinical data also implicate direct proximal tubular injury and, rarely, a collapsing glomerulopathy-like picture attributable to ribonucleotide reductase inhibition.

Clinical presentation

Rising creatinine with tachycardia, hypotension, edema, hypoxemia and a SIRS picture, often within the first cycle; a concurrent rise in uric acid, phosphate and potassium signals tumor lysis. Proteinuria has been described in severe cases. Hepatotoxicity (transaminitis, hyperbilirubinemia) and skin rash frequently co-occur and help flag the systemic toxicity syndrome.

Management

Interrupt clofarabine immediately for signs of SIRS or capillary leak; provide aggressive fluid resuscitation and hemodynamic support (vasopressors as needed), and consider corticosteroids for systemic inflammatory features. Treat concurrent tumor lysis with hydration, rasburicase/allopurinol and electrolyte correction. Discontinue the drug for severe or progressive renal injury; renal replacement therapy is reserved for refractory metabolic derangements or volume overload. Most cases improve with drug withdrawal and supportive measures.

Risk factors

  • High tumor burden / leukemic hyperleukocytosis
  • Concurrent sepsis or hypotension
  • Volume depletion
  • Concomitant nephrotoxins

Prevention

  • Vigorous IV hydration throughout the 5-day infusion course
  • Tumor lysis prophylaxis (allopurinol or rasburicase) in at-risk patients

Renal dose adjustment

Limited renal pharmacokinetic data; the label advises starting at a reduced dose and monitoring closely when CrCl is 30-60 mL/min, and clofarabine is not recommended (avoid) when CrCl is below 30 mL/min. Renal clearance accounts for a substantial fraction of elimination, so impaired clearance raises systemic exposure.

Dialyzability & ESKD dosing

Not formally characterized; no established supplemental dosing for hemodialysis. Given its small size and renal elimination, removal is theoretical, but it is not used in dialysis-dependent patients and HD is employed only to manage AKI complications, not to dose the drug.

Differential diagnosis

Distinguish drug-induced SIRS/capillary-leak prerenal AKI from sepsis-associated AKI (blood cultures, procalcitonin), from tumor lysis nephropathy (urate/phosphate elevation, uric-acid:creatinine ratio), and from ischemic ATN on the basis of urine microscopy (muddy-brown granular casts favor established ATN) and the temporal link to hypotension during infusion.

Monitoring

  • Vital signs and volume status frequently during each 5-day course (watch for hypotension/capillary leak)
  • Serum creatinine and electrolytes daily during and after each cycle
  • Uric acid, phosphate, potassium and calcium (tumor lysis) at initiation
  • Liver enzymes and bilirubin (concurrent hepatotoxicity)

Key trials & series

  • Jeha et al. phase II pediatric refractory/relapsed ALL trial (J Clin Oncol 2006) — basis of FDA approval
  • Jeha et al. phase I dose-finding study (Blood 2003)

Clinical pearls

  • Hypotension and capillary leak during the infusion are the key renal hazard — fluids and pressor support, not nephrotoxin avoidance alone, protect the kidney.
  • Co-occurring transaminitis and rash should raise suspicion for the systemic toxicity syndrome that drives the AKI.
  • Always layer tumor lysis prophylaxis on top, because rapid leukemic kill compounds the prerenal insult.

Anticancer mechanism

Second-generation deoxyadenosine (purine nucleoside) analog phosphorylated intracellularly to clofarabine triphosphate, which inhibits ribonucleotide reductase (depleting the dNTP pool) and competitively inhibits DNA polymerase, terminating chain elongation. It also disrupts mitochondrial membrane integrity with release of cytochrome c and apoptosis-inducing factor, triggering apoptosis independent of cell division. Used for relapsed or refractory pediatric acute lymphoblastic leukemia and, off-label, refractory acute myeloid leukemia.

Note

Renal injury is largely case-level; the SIRS/capillary-leak signal is the most consistently reported renal mechanism. The label carries a warning for capillary leak syndrome and SIRS.

Guidelines & consensus

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.

  • ADQI (2026) — Conventional cytotoxic chemotherapy-associated nephrotoxicity: consensus report of the 34th Acute Disease Quality Initiative (ADQI) WorkgroupCisplatin is identified as a leading cytotoxic nephrotoxin; the workgroup details preventive measures (adequate isotonic hydration, correction of volume depletion, avoidance of concurrent nephrotoxins, attention to electrolyte/magnesium wasting) and management of cisplatin-associated AKI, with a research agenda for knowledge gaps.Kidney Int · PMID 41881107
  • 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 (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknownsEvaluate 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.Kidney Int · PMID 38519239
  • 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

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

  1. 1.Phase II study of clofarabine in pediatric patients with refractory or relapsed acute lymphoblastic leukemia.Jeha S et al. · J Clin Oncol · 2006 · PMID 16622268
  2. 2.Clofarabine, a novel nucleoside analog, is active in pediatric patients with advanced leukemia.Jeha S et al. · Blood · 2003 · PMID 14551141
  3. 3.Clofarabine: in pediatric patients with acute lymphoblastic leukemia.Curran MP et al. · Paediatr Drugs · 2005 · PMID 16117562
  4. 4.Clofarabine-induced kidney toxicity.Jhaveri KD et al. · J Oncol Pharm Pract · 2013 · PMID 24081220
  5. 5.Recommendations for the evaluation of risk and prophylaxis of tumour lysis syndrome (TLS) in adults and children with malignant diseases: an expert TLS panel consensus.Cairo MS et al. · Br J Haematol · 2010 · PMID 20331465
  6. 6.New drug toxicities in the onco-nephrology world.Perazella MA et al. · Kidney Int · 2015 · PMID 25671763
  7. 7.Onconephrology: The intersections between the kidney and cancer.Rosner MH et al. · CA Cancer J Clin · 2020 · PMID 32853404
  8. 8.Efficacy and safety of clofarabine in relapsed and/or refractory non-Hodgkin lymphoma, including rituximab-refractory patients.Nabhan C et al. · Cancer · 2011 · PMID 21425150

Case reports & series (2)

The weakest rung of clinical evidence — single-patient and small-series reports, strongest first. Each carries a heuristic strength grade (A Strong / B Moderate / C Limited) inferred from its abstract and journal, not a formal appraisal. Weigh well below the primary references above.

  1. C1.[C · Limited]Clofarabine-associated acute kidney injury and proteinuria.Kintzel PE et al. · Pharmacotherapy · 2011 · PMID 21923594
  2. C2.[C · Limited]Hypertension and Life-Threatening Bleeding in Children with Relapsed Acute Myeloblastic Leukemia Treated with FLT3 Inhibitors.Yılmaz Karapınar D et al. · Turk J Haematol · 2015 · PMID 25912283
Educational monograph from NephTox (nephtox.com). Not medical advice — verify against current guidelines before any clinical decision.