Bosutinib
Bosulif · BCR-ABL TKI
Reversible eGFR decline.
PSEUDOPRE
MildOpen →
CSF1R tyrosine kinase inhibitor
Vimseltinib
Romvimza · CSF1R TKI
A clean-kidney targeted TKI — watch the CPK, not the nephron.
Mild2023-2026 targeted-therapy era · approved 2025
Symptomatic tenosynovial giant cell tumor (TGCT) not amenable to surgical resection (US accelerated/standard approval, 2025)
Signature kidney injury
Pseudo-AKI
No clinically significant direct nephrotoxicity was identified in the pivotal MOTION phase 3 trial. There is no recognized signature renal lesion (no ATN, AIN, TMA, or glomerular injury attributable to the drug). The kidney-relevant practical issue is interpretive: the dominant laboratory abnormality is treatment-emergent creatine phosphokinase (CPK) elevation — grade 3/4 in 8/83 (10%) of vimseltinib patients in MOTION — together with peripheral/periorbital edema, either of which can perturb serum creatinine or muscle-derived markers without true GFR loss. Renal-specific events were not reported as a notable safety signal.
Source: MOTION phase 3 (Gelderblom et al., Lancet 2024; PMID 38843860): the only grade 3/4 TEAE occurring in >5% of vimseltinib patients was increased blood CPK (10%); no clinically significant direct nephrotoxicity reported.
Toxicity fingerprint
Tap a signature to trace where it strikes the nephron.
Incidence not quantified
SeverityMild
ReversibilityReversible
Evidence0 refs
Nephron map
Vasculature / Endothelium
Proximal TubuleBulk reabsorption + drug uptake (OCT2, OATs)
Distal Tubule / Collecting Duct
Pseudo-AKI
The great mimic — a rise in creatinine from blocked tubular secretion (OCT2/MATE), NOT true injury. The GFR is intact; confirm with cystatin C before stopping effective therapy.
Mechanism of kidney injury
CSF1R inhibition has no established intrinsic nephrotoxic mechanism — the tubular and glomerular epithelium are not primary CSF1R-dependent compartments, and there is no VEGF, calcineurin, platinum, or immune-checkpoint pathway engaged that would predict ATN, TMA, AIN, or podocytopathy. The relevant kidney consideration is indirect and largely artifactual: (1) marked CPK elevation (a class effect of CSF1R inhibition, reflecting altered macrophage handling of muscle CK rather than true rhabdomyolysis in most cases) can confound muscle/renal lab interpretation; (2) peripheral and periorbital edema with fluid shifts may transiently alter volume status and creatinine; and (3) any creatinine rise is best regarded as pseudo-AKI or hemodynamic/prerenal rather than structural until proven otherwise. Class read-across from pexidartinib (the other approved CSF1R inhibitor for TGCT) similarly shows hepatic — not renal — as the organ of concern (PMID 33197285).
Clinical presentation
Typically no renal manifestation. When laboratory abnormalities arise, expect asymptomatic CPK elevation (often the most prominent grade 3/4 lab finding) and peripheral/periorbital edema. A modest, often reversible serum creatinine fluctuation may accompany edema or volume shifts but is generally not associated with structural kidney injury, active urinary sediment, or proteinuria. Frank AKI, nephrotic-range proteinuria, hematuria, or electrolyte-wasting syndromes are not characteristic and should prompt a search for an alternative cause.
Anticancer mechanism
Vimseltinib is an oral, switch-control tyrosine kinase inhibitor designed to selectively and potently inhibit the colony-stimulating factor 1 receptor (CSF1R). In tenosynovial giant cell tumor (TGCT), a translocation drives CSF1 overexpression, recruiting and sustaining CSF1R-bearing macrophage-lineage cells that form the tumor mass. By blocking CSF1R signaling, vimseltinib depletes this tumor-associated macrophage compartment, producing tumor regression and functional/symptomatic improvement. Its high kinase selectivity (sparing KIT, FLT3, and most class III/V RTKs) underlies a narrow off-target profile relative to less selective CSF1R/KIT inhibitors.
Management
For an isolated creatinine rise, assess volume status and reversible hemodynamic contributors first; correct volume depletion and hold/adjust concurrent diuretics or RAAS agents as appropriate. Check CPK and a urinalysis — bland sediment without proteinuria supports a pseudo-AKI/prerenal pattern rather than intrinsic injury. Manage CPK elevations and edema per the Romvimza label dose-modification scheme (dose interruption/reduction for significant or symptomatic elevations). Refer to nephrology and reconsider the diagnosis if there is true AKI, active sediment, new proteinuria, or features of TMA, none of which are expected from CSF1R inhibition. Avoid attributing structural kidney disease to the drug without supporting evidence.Lesion-level management framework
Risk factors
- Baseline volume depletion or concurrent diuretics/RAAS blockade (amplifies any prerenal creatinine rise)
- Pre-existing CKD limiting renal reserve
- High baseline muscle mass or strenuous activity (confounds CPK interpretation)
- Concomitant nephrotoxins or contrast that could unmask hemodynamic susceptibility
- Significant peripheral edema with intravascular volume contraction
Prevention
- Establish baseline serum creatinine, electrolytes, and CPK before starting
- Maintain euvolemia and review concomitant diuretics/nephrotoxins
- Interpret creatinine changes in the context of edema and CPK rather than assuming structural AKI
- Do not reflexively discontinue for isolated asymptomatic CPK elevation — follow per-label monitoring and dose-modification guidance
Note · Renal-specific literature for vimseltinib is essentially absent (no PubMed-indexed renal case reports or nephrotoxicity series as of the data retrieval). This profile therefore reasons primarily from the registrational MOTION phase 3 dataset and from CSF1R-inhibitor class behavior (pexidartinib), and states honestly that there is no recognized signature renal lesion. Signature classified as pseudo_aki because the chief kidney-relevant issue is interpretive (CPK/edema-confounded creatinine), with prerenal/hemodynamic as the realistic mechanism of any true creatinine rise; electrolyte included only as a minor monitoring consideration, not an established wasting syndrome. incidencePct set to null as no quantified direct-nephrotoxicity rate exists.
Clinical depth
Renal dose adjustment
No dedicated renal dose-adjustment requirement is established for clinically meaningful direct nephrotoxicity, as the drug is not a recognized nephrotoxin. Vimseltinib is given orally 30 mg twice weekly in 28-day cycles. Formal pharmacokinetic data in moderate-to-severe renal impairment and in dialysis patients are limited; prescribe with standard caution in advanced CKD and consult the current label for any renal/hepatic dosing language, since hepatic handling and CYP interactions are the more pertinent PK considerations for this agent.
Dialyzability & ESKD dosing
Not characterized. As a small-molecule kinase inhibitor that is highly protein-bound and predominantly hepatically metabolized, vimseltinib is unlikely to be meaningfully removed by hemodialysis, but no formal dialyzability data are available; do not assume dialysis clearance.
Differential diagnosis
A creatinine rise on vimseltinib should be worked up as pseudo-AKI/prerenal before structural injury is invoked. Distinguish from: (1) volume depletion/diuretic effect from edema management (prerenal — urine concentrated, bland sediment); (2) CPK-driven lab confounding versus true rhabdomyolysis-related AKI (check CPK trend, urine myoglobin); (3) unrelated intrinsic causes such as ATN from intercurrent illness, AIN from concomitant drugs (PPIs, antibiotics), or contrast exposure; and (4) for any TMA, proteinuria, or hypertension picture, look for an alternative agent (e.g., concurrent VEGF-pathway or platinum therapy), as these are not features of CSF1R inhibition.
Monitoring
- Serum creatinine and electrolytes at baseline and periodically
- CPK at baseline and during treatment (dominant lab signal; per-label monitoring)
- Volume/edema assessment at each visit
- Urinalysis if creatinine rises, to confirm bland sediment / exclude proteinuria or active sediment
- LFTs per label (hepatic, not renal, is the principal organ of concern for the CSF1R class)
Key trials & series
- MOTION (NCT05059262) — phase 3, double-blind, placebo-controlled; ORR 40% vs 0%; grade 3/4 CPK elevation in 10%, no significant direct nephrotoxicity (PMID 38843860)
- MOTION protocol/design paper (PMID 37593881)
- Pexidartinib long-term pooled analysis — class read-across showing hepatic, not renal, organ risk (PMID 33197285)
Clinical pearls
- Vimseltinib is essentially a kidney-sparing targeted agent — there is no signature renal lesion; the practical onconephrology task is interpreting creatinine in the setting of CPK elevation and edema, not managing drug-induced AKI.
- The headline lab abnormality is CPK elevation (grade 3/4 ~10% in MOTION), which is a CSF1R-class effect and usually asymptomatic — do not mistake it for rhabdomyolysis-driven AKI without supporting urine myoglobin/creatinine evidence.
- For the CSF1R inhibitor class (vimseltinib, pexidartinib), the organ to watch is the liver, not the kidney — pexidartinib carries a hepatotoxicity boxed warning, while vimseltinib in MOTION showed no cholestatic hepatotoxicity or drug-induced liver injury.
- Treat any creatinine rise as pseudo-AKI/prerenal until proven structural: assess volume, review diuretics, check a bland sediment.
- True AKI, proteinuria, TMA, or electrolyte-wasting on vimseltinib should trigger a hunt for an alternative cause rather than reflexive attribution to the drug.
Evidence
5 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkVimseltinib versus placebo for tenosynovial giant cell tumour (MOTION): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.Gelderblom H, Bhadri V, Stacchiotti S, et al. · Lancet 2024 · PMID 38843860Pivotal registrational phase 3 trial establishing efficacy and the full safety profile; documents CPK elevation as the dominant grade 3/4 lab abnormality (10%) and absence of a significant direct nephrotoxicity signal — the primary evidence base for the renal assessment.PMIDThe MOTION study: a randomized, phase III study of vimseltinib for the treatment of tenosynovial giant cell tumor.Tap WD, Sharma MG, Vallee M, et al. · Future Oncol 2023 · PMID 37593881Trial rationale and design for MOTION, including mechanism (selective switch-control CSF1R inhibition), dosing (30 mg twice weekly), and endpoints; contextualizes the safety dataset.PMIDMedical Management of Tenosynovial Giant Cell Tumor.Palmerini E, Trent JC, Hornicek FJ. · Curr Oncol Rep 2025 · PMID 40392406Current review of CSF1R-targeted systemic therapy for TGCT (vimseltinib, pexidartinib, others), framing class mechanism and the risk-benefit considerations relevant to organ safety.PMIDVimseltinib (Romvimza) for tenosynovial giant cell tumor.The Medical Letter on Drugs and Therapeutics. · Med Lett Drugs Ther 2025 · PMID 40254734Independent post-approval drug review summarizing dosing, efficacy, adverse effects, and drug interactions for the approved product; supports the practical monitoring and dose-modification framing.PMIDLong-term outcomes of pexidartinib in tenosynovial giant cell tumors.Gelderblom H, Wagner AJ, Tap WD, et al. · Cancer 2020 · PMID 33197285Class read-across: the other approved CSF1R inhibitor for TGCT, demonstrating that the principal organ toxicity of CSF1R inhibition is hepatic rather than renal — supporting the conclusion that the kidney is largely spared by this drug class.