Bendamustine
Treanda · Alkylator
Tumor lysis-mediated AKI is the principal risk; TMA is rare.
PRETMALYTE
ModerateOpen →
Radiopharmaceutical (alpha-emitter)
Radium-223 dichloride
Xofigo · RA223
A calcium-mimetic alpha-emitter that homes to bone metastases — the cleanest kidney of the radiopharmaceutical group.
MildBone-targeted alpha-emitter radiopharmaceutical · approved 2013
Castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastatic disease
Signature kidney injury
Prerenal / Hemodynamic AKI
Direct renal toxicity is minimal and not a recognized feature; renal labs are typically unaffected. The dominant toxicities are gastrointestinal (diarrhea, nausea) and myelosuppression. Any AKI is essentially always attributable to other causes (obstruction, dehydration, concomitant nephrotoxins).
Source: Parker et al., NEJM 2013
Mechanism of kidney injury
Minimal direct renal handling: excretion is predominantly fecal/intestinal, with only a minor renal/urinary component, and biodistribution studies show small, transient renal remnant activity that clears rapidly. There is no targeted renal irradiation. When AKI occurs it is hemodynamic/prerenal — typically GI fluid losses from treatment-related diarrhea — rather than a drug-specific tubular lesion.
Clinical presentation
GI symptoms (diarrhea, nausea, vomiting) and myelosuppression (anemia, thrombocytopenia, neutropenia) dominate. If a creatinine rise occurs it tracks volume status (diarrhea, poor intake) rather than a primary tubulopathy.
Onset
GI effects early; hematologic nadir over weeks. No characteristic renal onset.
Reversibility
Reversible
Anticancer mechanism
Calcium-mimetic alpha-emitter that incorporates into bone mineral at sites of high osteoblastic turnover (bone metastases), delivering short-range (<100 micron), high-linear-energy-transfer alpha radiation to adjacent tumor with minimal penetration into marrow or soft tissue.
Management
Supportive: rehydrate for volume-mediated prerenal AKI, manage GI symptoms, and support cytopenias. Hold injections for hematologic toxicity per label. No renal-specific antidote or renal dose modification is needed.
Risk factors
- Extensive marrow involvement / superscan and low marrow reserve
- GI fluid losses (diarrhea) causing volume depletion
- Concurrent nephrotoxins or obstructive pelvic disease
- Baseline CKD
Prevention
- Supportive hydration and management of diarrhea/GI losses
- CBC monitoring before each injection (hematologic safety)
- Avoid combination with abiraterone plus prednisone (ERA-223 fracture/death safety signal)
- No amino-acid renoprotection required
Note · Established (2013) alpha-emitter with a well-characterized non-renal toxicity profile; renal claims are deliberately framed as minimal/indirect, supported by biodistribution and registrational safety data.
Clinical depth
Renal dose adjustment
Standard 55 kBq/kg IV every 4 weeks for 6 injections. No renal dose adjustment is required given negligible renal clearance and exposure; holds are driven by hematologic parameters (ANC, platelets), not CrCl.
Dialyzability & ESKD dosing
Not a clinical consideration — minimal renal handling and no removable nephrotoxic moiety. No ESKD-specific dosing guidance is established.
Differential diagnosis
If AKI occurs, look beyond the drug: obstructive uropathy from pelvic disease, dehydration from GI losses, concomitant nephrotoxins, and baseline CKD — radium-223 itself is rarely the cause.
Monitoring
- CBC (hemoglobin, ANC, platelets) before each injection
- Volume status/weight if diarrhea occurs
- Renal monitoring is not specifically mandated for drug toxicity
Key trials & series
- ALSYMPCA (Parker, NEJM 2013) — registrational phase 3 RCT showing OS benefit with a favorable, non-renal toxicity profile
- Re-treatment phase 1/2 (Sartor, Prostate 2019) — no new renal safety signals over 2 years
Clinical pearls
- Excretion is mostly fecal — radium-223 is the 'clean kidney' agent of the radiopharmaceutical group.
- The toxicity story is marrow plus GI, not renal; no renal dose adjustment and no amino-acid renoprotection.
- Do not combine with abiraterone/prednisone (ERA-223 safety signal) — a key non-renal prescribing pearl.
- A rising creatinine on radium-223 should trigger a hunt for obstruction or volume depletion, not radiation nephropathy.
Where it strikes
Nephron segments
Vasculature / Endothelium
Glomerular & peritubular capillaries
Injury signatures
Prerenal / Hemodynamic AKI
Evidence
6 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkAlpha emitter radium-223 and survival in metastatic prostate cancer.Parker C et al. · N Engl J Med 2013 · PMID 23863050ALSYMPCA registrational RCT — OS benefit and favorable, predominantly non-renal toxicity profile.PMIDWhole-Body and Microenvironmental Localization of Radium-223 in Naive and Mouse Models of Prostate Cancer Metastasis.Abou DS et al. · J Natl Cancer Inst 2015 · PMID 26683407Biodistribution mechanism — bone-targeted with only a minor renal remnant, supporting minimal renal handling.PMIDThe impact of age on radium-223 distribution and an evaluation of molecular imaging surrogates.Jiang W et al. · Nucl Med Biol 2018 · PMID 29800797Confirms rapid soft-tissue (including renal) clearance with stable bone uptake — minimal renal radiation exposure.PMIDRe-treatment with radium-223: 2-year follow-up from an international, open-label, phase 1/2 study in patients with castration-resistant prostate cancer and bone metastases.Sartor O et al. · Prostate 2019 · PMID 31442327Re-treatment safety — minimal hematologic toxicity and no renal-specific concerns over 2 years.PMIDSafety and activity of radium-223 in metastatic castration-resistant prostate cancer: the experience of Istituto Nazionale dei Tumori.Raimondi A et al. · Tumori 2020 · PMID 32116138Real-world safety cohort — main grade 3/4 events were anemia/thrombocytopenia/fatigue; renal toxicity not a feature.PMIDRadium-223 dichloride in prostate cancer: proof of principle for the use of targeted alpha treatment in clinical practice.Dizdarevic S et al. · Eur J Nucl Med Mol Imaging 2019 · PMID 31471713Systematic review of targeted alpha therapy confirming radium-223 is well tolerated with a non-renal toxicity profile.
Related agents
Other agents sharing the same signature kidney injury.