mTOR inhibitor
Sirolimus
Rapamune · SIR
mTOR inhibitor · approved 1999 · 10 references
An mTOR inhibitor long called 'non-nephrotoxic' that can nonetheless unmask podocyte injury, proteinuria, and stall tubular repair.
- Signature injury
- Glomerular Injury / Proteinuria
- Severity
- Moderate
- Reversibility
- Partially reversible
- Onset
- Variable—weeks to months after initiation or dose escalation; proteinuria characteristically emerges or worsens within months after calcineurin-inhibitor withdrawal/conversion.
Signature kidney injury & incidence
Glomerular Injury / Proteinuria — representative incidence ~23.1%.
New or worsening proteinuria occurs in a substantial minority of treated patients in transplant cohorts (more pronounced after conversion from a calcineurin inhibitor than with de novo use), but oncology-specific renal incidence is not well quantified and is described largely at the case and small-series level. Acute renal dysfunction (e.g., delayed graft recovery) is recognized but variable. Reported rate: proteinuria in 23.1% — 18 of 78 kidney, pancreas and islet transplant recipients given sirolimus de novo or after conversion, 5 of the 18 (27.8%) reaching nephrotic range; a transplant-immunosuppression figure, not an oncology one (Franco 2007, PMID 17362756).
Source: Franco et al., Transplant Proc 2007 (transplant cohort, proteinuria 23.1%); Diekmann, Transplant Rev 2012
Reported injury signatures: Glomerular Injury / Proteinuria, Acute Tubular Necrosis.
Renal toxicity profile
- Glomerular Injury / ProteinuriaPrimary~23.1%proteinuria in ~23% of transplant recipients on sirolimus (de novo or after CNI conversion), occasionally FSGS
- Acute Tubular NecrosisSecondary
Onset timing & rechallenge
Variable / unpredictable — Weeks to months after initiation or dose escalation; proteinuria often worsens months after calcineurin-inhibitor conversion.
Mechanism of kidney injury
Clinical presentation
Management
Risk factors
- Pre-existing chronic kidney disease or reduced GFR
- Underlying glomerular disease (e.g., FSGS)
- Conversion from a calcineurin inhibitor to sirolimus
- Higher drug trough levels
Prevention
- Therapeutic drug-level monitoring to avoid excessive troughs
- RAAS blockade (ACE inhibitor or ARB) if proteinuria develops
- Avoid use in patients with significant pre-existing glomerular injury when alternatives exist
Renal dose adjustment
Dialyzability & ESKD dosing
Differential diagnosis
Monitoring
- Whole-blood sirolimus trough levels (therapeutic drug monitoring)
- Urine protein/creatinine ratio at baseline and periodically
- Fasting lipid panel (frequent hyperlipidemia)
- Serum creatinine at baseline and periodically
Key trials & series
- Letavernier CJASN 2007 sirolimus de novo FSGS series
- Cho AJKD 2007 sirolimus-in-FSGS trial halted for nephrotoxicity
- Diekmann Transplant Rev 2012 mTOR-inhibitor proteinuria analysis
Clinical pearls
- Proteinuria classically appears or worsens after switching from a calcineurin inhibitor to sirolimus—check a baseline UPCR before conversion.
- Because mTOR inhibition blocks tubular regeneration, avoid starting sirolimus in the early post-transplant or post-ATN window when repair is most needed.
- High troughs are the modifiable driver of de novo FSGS—keep levels low and recheck proteinuria after any escalation.
Anticancer mechanism
Note
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) — 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
10 peer-reviewed references. Citation metadata via PubMed / NLM.
- 1.Proteinuria in transplant patients associated with sirolimus.Franco AFV et al. · Transplant Proc · 2007 · PMID 17362756
- 2.Sirolimus-associated proteinuria and renal dysfunction.Rangan GK · Drug Saf · 2006 · PMID 17147461
- 3.Sirolimus therapy of focal segmental glomerulosclerosis is associated with nephrotoxicity.Cho ME et al. · Am J Kidney Dis · 2007 · PMID 17261434
- 4.High sirolimus levels may induce focal segmental glomerulosclerosis de novo.Letavernier E et al. · Clin J Am Soc Nephrol · 2007 · PMID 17699432
- 5.Sirolimus interacts with pathways essential for podocyte integrity.Letavernier E et al. · Nephrol Dial Transplant · 2008 · PMID 18927120
- 6.mToR inhibitors-induced proteinuria: mechanisms, significance, and management.Letavernier E et al. · Transplant Rev (Orlando) · 2008 · PMID 18631865
- 7.mTOR inhibitor-associated proteinuria in kidney transplant recipients.Diekmann F et al. · Transplant Rev (Orlando) · 2012 · PMID 22137729
- 8.mTOR-mediated podocyte hypertrophy regulates glomerular integrity in mice and humans.Puelles VG et al. · JCI Insight · 2019 · PMID 31534053
- 9.Role of apoptosis in the pathogenesis of acute renal failure.Bonegio R et al. · Curr Opin Nephrol Hypertens · 2002 · PMID 11981260
- 10.Strategies for the management of adverse events associated with mTOR inhibitors.Kaplan B et al. · Transplant Rev (Orlando) · 2014 · PMID 24685370
Case reports & series (3)
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.
- C1.[C · Limited]Proteinuria developing after clinical islet transplantation resolves with sirolimus withdrawal and increased tacrolimus dosing.Senior PA et al. · Am J Transplant · 2005 · PMID 16095517
- C2.[C · Limited]Thrombotic microangiopathy in marginal kidneys after sirolimus use.Pellé G et al. · Am J Kidney Dis · 2005 · PMID 16310579
- C3.[C · Limited]Sirolimus may promote thrombotic microangiopathy.Saikali JA et al. · Am J Transplant · 2003 · PMID 12603218