Comparison of ferumoxytol- and gadolinium chelate-enhanced MRI for assessment of sarcomas in children and adolescents.

OBJECTIVES: We compared the value of ferumoxytol (FMX)- and gadolinium (Gd)-enhanced MRI for assessment of sarcomas in paediatric/adolescent patients and hypothesised that tumour size and morphological features can be equally well assessed with both protocols. METHODS: We conducted a retrospective study of paediatric/adolescent patients with newly diagnosed bone or soft tissue sarcomas and both pre-treatment FMX- and Gd-MRI scans, which were maximal 4 weeks apart. Both protocols included T1- and T2-weighted sequences. One reader assessed tumour volumes, signal-to-noise ratios (SNR) of the primary tumour and adjacent tissues and contrast-to-noise ratios (CNR) of FMX- and Gd-MRI scans. Additionally, four readers scored FMX- and Gd-MRI scans according to 15 diagnostic parameters, using a Likert scale. The results were pooled across readers and compared between FMX- and Gd-MRI scans. Statistical methods included multivariate analyses with different models. RESULTS: Twenty-two patients met inclusion criteria (16 males, 6 females; mean age 15.3 ± 5.0). Tumour volume was not significantly different on T1-LAVA (p = 0.721), T1-SE (p = 0.290) and T2-FSE (p = 0.609) sequences. Compared to Gd-MRI, FMX-MRI demonstrated significantly lower tumour SNR on T1-LAVA (p < 0.001), equal tumour SNR on T1-SE (p = 0.104) and T2-FSE (p = 0.305), significantly higher tumour-to-marrow CNR (p < 0.001) on T2-FSE as well as significantly higher tumour-to-liver (p = 0.021) and tumour-to-vessel (p = 0.003) CNR on T1-LAVA images. Peritumoural and marrow oedema enhanced significantly more on Gd-MRI compared to FMX-MRI (p < 0.001/p = 0.002, respectively). Tumour thrombi and neurovascular bundle involvement were assessed with a significantly higher confidence on FMX-MRI (both p < 0.001). CONCLUSIONS: FMX-MRI provides equal assessment of the extent of bone and soft tissue sarcomas compared to Gd-MRI with improved tumour delineation and improved evaluation of neurovascular involvement and tumour thrombi. Therefore, FMX-MRI is a possible alternative to Gd-MRI for tumour staging in paediatric/adolescent sarcoma patients. KEY POINTS: • Ferumoxytol can be used as an alterative to gadolinium chelates for MRI staging ofpaediatric sarcomas. • Ferumoxytol-enhanced MRI provides equal assessment of tumour size and other diagnostic parameters compared to gadolinium chelate-enhanced MRI. • Ferumoxytol-enhanced MRI provides improved delineation of sarcomas from bone marrow, liver and vessels compared to gadolinium chelate-enhanced MRI.

Comparative liver function assessment of natural and available drug (Ferrous sulfate) for iron-deficiency anemia in rat model.

To assess the comparative effect of anti-anaemic drug (ferrous sulfate) with naturally occurring anti-anaemic compound (Illicium verum commonly called star anise) on liver in rat model. Model and both test groups were made anaemic. Ferrous sulfate was given to T1 group of rats as 30mg/kg body weight (b.w) and Illicium verum to T2 group of rats with dose of 80mg/kg b.w for six weeks. Illicium verum treated group (T2 rats) produced depression, decreased anxiety and enhanced short-term memory, whereas ferrous sulfate treated group (T1 rats) enhanced long term memory. The liver function test of T2 rats showed that the total bilirubin was in normal range, but direct bilirubin, SGPT, ALP and GGT were significantly decreased in T2 rats in comparison with T1 and also from model group of rats. It was concluded in this study that by comparing the effect of ferrous sulfate with naturally occurring Illicium verum on iron-defficiency anaemia, illicium verum produces same effects and can be used to treat iron-defficiency anaemia without affecting liver function.

Impact of Erythropoiesis-Stimulating Agents on Behavioral Measures in Children Born Preterm.

OBJECTIVE: To evaluate the impact of erythropoiesis-stimulating agents (ESAs) administered during initial hospitalization and family demographic factors on behavior at 3.5-4 years of age. STUDY DESIGN: Children were enrolled who had previously participated in a randomized study of ESAs (n = 35) or placebo (n = 14) in infants born preterm with birth weights of 500-1250 g. A term healthy control group (n = 22) also was recruited. Behavior was evaluated by parent report with the Behavioral Assessment System of Children-2. Principal component analyses identified 2 demographic factors, a Socioeconomic Composite (SEC) and a Family Stress Composite. A multivariate general linear model evaluated the impact of study group and sex on the 4 composite scales of the Behavioral Assessment System of Children-2. Demographic factors were treated as covariates and interactions with study group (ESA, placebo, and term) were examined. RESULTS: The ESA group had significantly better scores than the placebo group on behavioral symptoms (P = .04) and externalizing scales (P = .04). An interaction was observed between study group and SEC (P = .001). A beneficial effect of ESAs was maximal in the children with lower SEC scores. CONCLUSIONS: The beneficial effects of ESAs on childhood behavior were maximal in children with lower SEC scores. ESAs seemed to ameliorate the adverse impact of lower SEC on behavioral domains seen in the placebo group. This effect was independent of the beneficial effect of ESAs on global cognition we reported previously. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01207778 and NCT00334737.

Assessment of hemoglobin responsiveness to epoetin alfa in patients on hemodialysis using a population pharmacokinetic pharmacodynamic model.

A population pharmacokinetic pharmacodynamic (PK/PD) model describing the effect of epoetin alfa on hemoglobin (Hb) response in hemodialysis patients was developed. Epoetin alfa pharmacokinetics was described using a linear 2-compartment model. PK parameter estimates were similar to previously reported values. A maturation-structured cytokinetic model consisting of 5 compartments linked in a catenary fashion by first-order cell transfer rates following a zero-order input process described the Hb time course. The PD model described 2 subpopulations, one whose Hb response reflected epoetin alfa dosing and a second whose response was unrelated to epoetin alfa dosing. Parameter estimates from the PK/PD model were physiologically reasonable and consistent with published reports. Numerical and visual predictive checks using data from 2 studies were performed. The PK and PD of epoetin alfa were well described by the model.

[Effects of dose of erythropoiesis stimulating agents on cardiovascular outcomes, quality of life and costs of haemodialysis. the clinical evaluation of the DOSe of erythropoietins (C.E. DOSE) Trial]. / Effetti della dose degli agenti stimolanti l'eritropoiesi su esiti cardio-cerebrovascolari, qualità di vita e costi in emodialisi.

BACKGROUND: Anaemia is a risk factor for death, adverse cardiovascular outcomes and poor quality of life in patients with chronic kidney disease (CKD). Erythropoietin Stimulating Agents (ESA) are the most used treatment option. In observational studies, higher haemoglobin (Hb) levels (around 11-13 g/dL) are associated with improved survival and quality of life compared to Hb levels around 9-10 g/dL. Randomized studies found that targeting higher Hb levels with ESA causes an increased risk of death, mainly due to adverse cardiovascular outcomes. It is possible that this is mediated by ESA dose rather than haemoglobin concentration, although this hypothesis has never been formally tested. METHODS: We present the protocol of the Clinical Evaluation of the Dose of Erythropoietins (C.E. DOSE) trial, which will assess the benefits and harms of a high versus a low ESA dose therapeutic strategy for the management of anaemia of end stage kidney disease (ESKD). This is a randomized, prospective open label blinded end-point (PROBE) design trial due to enroll 900 haemodialysis patients. Patients will be randomized 1:1 to 4000 UI/week i. v. versus 18000 UI/week i. v. of epoetin alfa, beta or any other epoetin in equivalent doses. The primary outcome of the trial is a composite of cardiovascular events. In addition, quality of life and costs of these two strategies will be assessed. The study has been approved and funded by the Italian Agency of Drugs (Agenzia Italiana del Farmaco (AIFA)) within the 2006 funding plan for independent research on drugs (registered at www.clinicaltrials.gov (NCT00827021)).

Pre-emptive replacement of water treatment components improves responsiveness to erythropoiesis-stimulating agents in maintenance haemodialysis patients: a quality improvement report.

Hypo-responsiveness to erythropoiesis-stimulating agents (ESAs) has been associated with increased mortality. We examined the effect of water treatment component replacement on declining ESA responsiveness in the absence of chemical or microbiological standards failure. Pre-emptive renewal of the water treatment system supplying 802 standard-flux haemodialysis patients resulted in a significant rise in haemoglobin from (mean ± SD) 12.1 ± 1.2 to 12.3 ± 1.0 g/dl (p < 0.0001), accompanied by a significant decrease in prescribed dose of darbepoetin alfa from 47.9 ± 27.3 to 44.7 ± 27.6 µg/week (p < 0.0001). ESA responsiveness improved significantly from 0.060 ± 0.041 to 0.055 ± 0.040 µg/kg/g · dl(-1) (p < 0.0001) and the number of patients no longer requiring ESA therapy increased threefold. These benefits were derived in the absence of haemolysis or significant changes in water quality. Renewal of water system components should be conducted even in the absence of proven microbiological and chemical failure.

Erythropoiesis-stimulating agents in renal medicine.

The four currently available erythropoiesis-stimulating agents (ESAs), the main drugs for correcting anemia in patients with chronic kidney disease (CKD), are epoetin alfa, epoetin beta, darbepoetin alfa, and continuous erythropoietin receptor activator. The last two have much longer half-lives, which means they can be administered less frequently. The expiry of the patents for epoetin alfa and epoetin beta some years ago opened up the way for the production of a number of biosimilars that are now marketed in the European Union. Because biosimilars cannot be identical to their originator, a complex and still-evolving regulatory policy has been generated, but there are still a number of issues concerning international naming, automatic substitution, and safety. All ESAs are effective in correcting renal anemia and increasing hemoglobin levels, but the choice of which to use should also take into account their pharmacokinetics and pharmacodynamics, their administration route, and economic issues. Following the publication of a number of trials indicating no benefit (and even possible harm) when ESAs are used to aim at near-normal hemoglobin levels in CKD patients, the hemoglobin target has become a major subject of discussion. According to the position statement of the Anemia Group of the European Renal Best Practice, it should generally be about 11-12 g/dL; however, a risk-benefit evaluation is warranted in individual patients, and high ESA doses driven by hyporesponsiveness should be avoided.

Cardiovascular risks of anemia correction with erythrocyte stimulating agents: should blood viscosity be monitored for risk assessment?

To date, all major clinical trials for anemia correction using erythrocyte stimulating agents (ESAs) failed to show improved outcomes for cardiovascular disease (CVD), stroke, and vascular thrombosis. Even moderate elevations in hemoglobin (e.g., to 13 g/dL) using erythropoietin have been associated with significantly increased risk of thrombotic cardiovascular events and heart failure. This review presents a biophysical rationale for increased risk of CVD among certain patients treated with ESAs and suggests a risk management approach based on blood viscosity. Whole blood viscosity is a key determinant of the work of the heart, and elevated blood viscosity appears to be both a strong predictor of cardiovascular disease and an important pathophysiological factor in the development of atherothrombosis. Blood donation has been shown to reduce viscosity. Reflecting these findings, studies in male blood donors and in women of premenopausal age with regular menstruation have shown reduced incidence of cardiovascular events such as myocardial infarction, angina, stroke, and the requirement for procedures such as percutaneous transluminal coronary angioplasty and coronary artery bypass graft compared with non-donors and postmenopausal women, respectively. We propose that blood viscosity monitoring should be considered as part of a cardiovascular risk assessment, whenever an increased cardiovascular risk is detected and particularly in the context of anemia correction.

Biochemical assessment of erythropoietin products from Asia versus US Epoetin alfa manufactured by Amgen.

We compared the physical and chemical properties of purported copies of recombinant human erythropoietin (rHuEPO) purchased from Korea, China, and India with the innovator product, Epoetin alfa, manufactured by Amgen Inc. The products were characterized for similarity in the types of glycoforms present, the relative degree of unfolding, in vitro potency, presence of covalent aggregates, and presence of cleavage products using established analytical methods. All products were different from Epoetin alfa (Epogen). The purported copies of rHuEPO from Korea, India, and China contained more glycoforms and other impurities. The in vitro relative potency varied for each product when based on the labeled concentration, while the concentration based on ELISA analysis brought the relative potency, for most products closer to 100%. These data emphasize potential biochemical discrepancies resulting from different cell lines and manufacturing processes. Concentrations varied within products and did not always match the information provided on the product label. As it is not possible to reliably correlate such biochemical discrepancies to clinical consequences, or the lack thereof, these data support the need for extensive preclinical testing and clinical testing of all investigational products as not all safety and efficacy aspects can be assessed during preclinical evaluation.

Use of erythropoiesis-stimulating agents in patients with anemia of chronic kidney disease: overcoming the pharmacological and pharmacoeconomic limitations of existing therapies.

Stage 3 chronic kidney disease (CKD), which is characterized by a glomerular filtration rate of 30 to 60 mL/min/1.73 m2 (reference range, 90-200 mL/min/1.73m2 for a 20-year-old, with a decrease of 4 mL/min per decade), affects approximately 8 million people in the United States. Anemia is common in patients with stage 3 CKD and, if not corrected, contributes to a poor quality of life. Erythropoiesis-stimulating agents (ESAs), introduced almost 2 decades ago, have replaced transfusions as first-line therapy for anemia. This review summarizes the current understanding of the role of ESAs in the primary care of patients with anemia of CKD and discusses pharmacological and pharmacoeconomic issues raised by recent data. Relevant studies in the English language were identified by searching the MEDLINE database (1987-2006). Two ESAs are currently available in the United States, epoetin alfa and darbepoetin alfa. More frequent dosing with epoetin alfa is recommended by the labeled administration guidelines because it has a shorter half-life than darbepoetin alfa. Clinical experience also supports extended dosing intervals for both these ESAs. Use of ESAs in the management of anemia of CKD is associated with improved quality of life, increased survival, and decreased progression of renal failure. Some evidence suggests that ESAs have a cardioprotective effect. However, correction of anemia to hemoglobin levels greater than 12 g/dL (to convert to g/L, multiply by 10) appears to increase the risk of adverse cardiac outcomes and progression of kidney disease in some patients. The prescription of ESAs in the primary care setting requires an understanding of the accepted use of these agents, the associated pharmacoeconomic challenges, and the potential risks. This review considers the need to balance effective ESA dosing intervals against the potential risks of treatment.

Blood conservation in the critically ill.

PURPOSE: Anemia of critical illness is common among intensive care unit patients. A blood management pilot program was initiated to study the pharmacodynamic response of epoetin alfa in critically ill patients and assess the impact of the use of a standardized order set of pharmaceuticals, including epoetin alfa and intravenous iron sucrose, on the quantity of red blood cell units transfused in the adult intensive care unit. SUMMARY: A pre-printed order set was developed which included baseline and follow-up laboratory monitoring and pharmaceutical options for iron, either intravenous and/or oral, folic acid, ascorbic acid, cyancobalamin, and weight-based epoietin alfa. Laboratory studies included: hemoglobin/hematocrit, reticulocyte count, absolute reticulocyte count, immature reticulocyte fraction obtained at baseline, and on day three and day five; in addition, iron, total iron binding capacity, transferrin saturation, and ferritin were obtained at baseline and on day five. An average hemoglobin response of 0.8 g/dL five days after administration of epoetin alfa was demonstrated in a diverse population of critically ill patients. Patients who received intravenous iron did not have a difference in mortality as compared to those patients who did not receive intravenous iron; however, there was a significantly longer length of stay. The cost of epoetin alfa was $64,000 over 10 months (approximately 8-10 patients/month). Transfusions of RBCs in adult intensive care unit decreased over the initial five months of the pilot study. CONCLUSION: Use of erythropoiesis stimulating agents (ESAs) in the critically ill is controversial. Implementing a standardized approach in the pharmaceutical management of anemia in the critically ill patient is possible. Limitations with the order set and standardized protocol included errors in selection of dose/weight, incomplete laboratory/monitoring, and inconsistent prospective/concurrent review to guide therapy. The determination of the cost-effectiveness of epoetin alfa therapy in anemia of critical illness was not the purpose of this project, but will be the focus of future studies.

An assessment of recombinant human erythropoietin effect on reticulocyte production rate and lifespan distribution in healthy subjects.

PURPOSE: An empirical pharmacodynamic model was developed to assess the effect of recombinant human erythropoietin (rHu-EPO) treatment on the reticulocyte production rate and lifespan distribution. MATERIALS AND METHODS: Single doses of rHu-EPO at levels 20, 40, 60, 90, 120, and 160 kIU were administered to healthy volunteers (n = 8 per dose level). Erythropoietin plasma concentrations as well as hematologic responses were measured up to 42 days. The hematological data were used to determine explicit relationships between reticulocyte and red blood cell counts (RBC) and the reticulocytes' production rate and lifespan distribution. RESULTS: The parameter estimates obtained by simultaneous fitting of the model to the reticulocyte and RBC data revealed that rHu-EPO transiently increased the reticulocyte lifespan from the baseline value of 1.7 days to 3.4 days and the effect lasted for 8.3 days. The dose dependent increase in the reticulocyte production had the maximal value of 77.5 10(9) cells/l/day and was followed by a rebound that was less than 9% of the baseline value. Both reticulocyte and RBC responses were preceded by a dose-independent lag time of 1.7 days. CONCLUSIONS: The effect of rHu-EPO on the reticulocyte production rate and lifespan distribution was characterized. The results of the present study can be further utilized in building more mechanistic pharmacodynamic models of rHu-EPO stimulatory effects.

Clinical and economic comparison of epoetin alfa and darbepoetin alfa.

BACKGROUND: The pharmacoeconomics of erythropoietic therapy for the treatment of anemia is receiving renewed attention due to the current availability of two agents. Epoetin alfa has been the standard of therapy for patients with renal disease and cancer-related anemia for more than a decade. Darbepoetin alfa, an alternative agent, is now approved for anemia resulting from renal disease and cancer chemotherapy. METHODOLOGY: Although direct comparative trials have not been performed with these agents, information published in the last several years regarding their clinical efficacy, safety, and dosing is sufficient, in most cases, to compare costs. With the disclaimer that any efficacy comparison of competing products using published reports has certain limitations, a cost-minimization approach from a provider's perspective was conducted. RESULTS: To provide background for the economic evaluation, pharmacokinetic and pharmacodynamic data for these two agents are discussed. Recent clinical trials in the nephrology and oncology therapeutic areas are summarized, highlighting study designs, dosing regimens, patient entry criteria, study endpoints, and published results. Cost data, based on average wholesale prices (AWP) in 2003, are compared and calculated from available clinical data with an emphasis on efficacy. CONCLUSION: These evaluations largely conclude that epoetin alfa is the better pharmacoeconomic value of the two currently available erythropoietic agents.

Parity as a determinant of the hematologic response to hematinics supplementation in underprivileged pregnant women in Malaysia.

The effect of parity on the hematological response to supplemental hematinics and the relationship between birth weight and Hb concentration were examined in 67 pregnant rural Kelantanese Malay women recruited at 20-24 weeks of gestation. Among initially anemic women (Hb concentration at recruitment < 110 g/l), a significant supplementation effect was observed in the lower parae (3 or less children) but not in the higher parae. Among initially nonanemic women, a progressive decline in mean Hb concentration was observed in the higher parae; in the lower parae, however, an initial fall in mean Hb concentration was followed by a rise to almost the initial level. Birth weight was inversely related to initial Hb concentration. There was no association between birth weight and final measured Hb level, parity or any of the measured maternal characteristics. These observations suggest: a) women with initially lower Hb concentration might have experienced a greater acceleration of plasma volume expansion than those with initially higher Hb level; and b) hemopoiesis might be impaired in the higher multiparae.