The safety and efficacy of ferumoxytol therapy in anemic chronic kidney disease patients

Utility of a new bolus-injectable nanoparticle for clinical cancer staging

BACKGROUND

In this study, we report on the use of a new, bolus-injectable, carboxymethyl dextran-based magnetic nanoparticle (MNP), ferumoxytol, to improve detection in loco-regional lymph nodes by magnetic resonance imaging (MRI).

METHODS

This preliminary study was performed as a prospective, single-center, open label pilot study to determine the magnitude of nodal MRI signal changes and to determine the optimal time points for imaging following intravenous (IV) bolus injection of the MNP. The study group consisted of 10 patients, all of whom were diagnosed with prostate cancer before any systemic therapy.

RESULTS

All 10 patients had lymph nodes evaluated by histopathology. Of the evaluated 26 lymph nodes, 20 were benign and 6 were malignant. The mean short-axis diameter of benign lymph nodes was 6 mm and the mean short-axis diameter of malignant lymph nodes was 7 mm. Following IV administration, there was a significant change in mean signal-to-noise ratio (SNR) of benign lymph nodes (P < .0001) whereas there was little change in the mean SNR of malignant nodes (P = .1624). No adverse events were encountered.

CONCLUSION

Ferumoxytol is safe and, at the appropriate circulation interval, modulates nodal signal intensity, allowing for identification of malignant nodal involvement by MRI.

Iron deficiency in patients with chronic kidney disease: potential role for intravenous iron therapy independent of erythropoietin

The prevalence of iron deficiency and its contribution to the anemia of end stage renal disease has been extensively studied, but much less is known about the role of iron deficiency in the pathogenesis of the anemia of chronic kidney disease in predialysis patients. All new hemodialysis patients entering a single hemodialysis unit between July 1999 and April 2002 were included in the study. The admission laboratory tests and the Health Care Financing Administration (HCFA) 2728 form were examined to determine the prevalence of erythropoietin use, anemia (Hb<11 g/dl), and iron deficiency (ferritin<100 ng/ml and transferrin saturation %<20%). In a second part of the study, the effect of intravenous iron gluconate replacement in patients with stage III & IV chronic kidney disease was examined. Anemia was present in 68% of all patients starting hemodialysis. Iron deficiency was a common feature occurring in 29% of patients taking erythropoietin (49% of all patients) and 26% of patients without erythropoietin (51% of all patients). Following the administration of intravenous iron gluconate to four patients, there was a significant rise in hemoglobin levels from 10.6+/-0.19 to 11.7+/-g/dl (p=0.02).

CONCLUSION

Iron deficiency is common in predialysis patients. Replenishing iron stores in anemic patients with chronic kidney disease significantly increases hemoglobin levels and should be considered as an integral part of the therapy for treating anemia in the predialysis population.

Update on clinical practice recommendations and new therapeutic modalities for treating anemia in patients with chronic kidney disease

PURPOSE

The National Kidney Foundation (NKF) clinical practice recommendations for treating anemia in chronic kidney disease (CKD) and the dosing, route and frequency of administration, efficacy, and safety of currently available and investigational drug therapies for anemia in patients with CKD, including the erythropoietin-stimulating agents (ESAs) iron replacement, and adjuvants, are described.

SUMMARY

The NKF recommendations for ESA use are general and include dosing based on the measured and target hemoglobin concentrations, the rate of increase in hemoglobin, and clinical circumstances, with the route and frequency of administration determined by the CKD stage, treatment setting, efficacy, and ESA class. A serum ferritin concentration of 100-500 ng/mL is the target during oral and intravenous (i.v.) iron therapy for predialysis and peritoneal dialysis patients, but use of the i.v. route of administration and a target serum ferritin concentration of 200-500 ng/mL is recommended for hemodialysis patients by NKF. Iron deficiency and inflammation are possible causes of inadequate response to ESAs. The safety profile of epoetin alfa and darbepoetin alfa are similar, but the longer half-life of darbepoetin alfa permits administration on a once-monthly basis in patients with CKD and anemia. Extended dosing of CERA also appears safe and effective in dialysis patients with CKD. Several investigational anemia therapies with a variety of mechanisms of action are in development.

CONCLUSION

Efforts by the NKF to update their clinical practice recommendations provide clinicians with insight into the optimal therapeutic approach to treating anemia in patients with CKD. Clinical research has resulted in the development of new therapeutic modalities to improve outcomes in patients with CKD and anemia.

Intravenous versus Oral Iron Supplementation in Peritoneal Dialysis Patients

Iron supplementation is required in a preponderance of peritoneal dialysis (PD) patients treated with erythropoietic stimulatory agents (ESAs). Although many authors and clinical practice guidelines recommend primary oral iron supplementation in ESA-treated PD patients, numerous studies have clearly demonstrated that, because of a combination of poor bioavailability of oral iron, gastrointestinal intolerance, and noncompliance, oral iron supplementation is insufficient for maintaining a positive iron balance in these patients over time. Controlled trials have demonstrated that, in iron-deficient and iron-replete PD patients alike, intravenous (IV) iron supplementation results in superior iron stores and hemoglobin levels with fewer side effects than oral iron produces. Careful monitoring of iron stores in patients receiving IV iron supplementation is important in view of conflicting epidemiologic links between IV iron loading and infection and cardiovascular disease. Emerging new iron therapies such as heme iron polypeptide and ferumoxytol may further enhance the tolerability, efficacy, and ease of administration of iron in PD patients.