Utilization of darbepoetin alfa and epoetin alfa for chemotherapy-induced anemia.

PURPOSE: The patterns of use and effectiveness of therapy with darbepoetin alfa and epoetin alfa for chemotherapy-induced anemia (CIA) in hospital outpatient and community settings were evaluated. METHODS: Data were collected from medical charts at 65 oncology clinics in hospital outpatient and community settings for consecutive patients who received the first dose of either darbepoetin alfa or epoetin alfa between August 1, 2002, and February 15, 2003, and were to have had 12 weeks of follow-up data. RESULTS: Data from the charts of 3123 patients were abstracted. Of these patients, 2785 were treated with only one erythropoietic agent (1444 with darbepoetin alfa and 1341 with epoetin alfa) and were included in the analysis. The most common initial dosage of darbepoetin alfa was 200 microg every two weeks (61% of darbepoetin alfa recipients), and the most common initial dosage of epoetin alfa was 40,000 units weekly (72%). With these regimens, the dosage was escalated for 22% of darbepoetin alfa recipients and 23% of epoetin alfa recipients at a median of six weeks after the initial dose. The mean change from baseline in hemoglobin concentration after 12 weeks of therapy was similar for both groups, as was the percent of patients with red-blood-cell transfusions during treatment. CONCLUSION: The most common initial dosage of darbepoetin alfa for CIA was 200 microg every two weeks, and the most common initial dosage of epoetin alfa was 40,000 units weekly. At these dosages, the two agents appear to have similar clinical effectiveness.     

Evaluation of the US Oncology Network's recommended guidelines for therapeutic substitution with darbepoetin alfa 200 microg every 2 weeks in both naïve patients and patients switched from epoetin alfa

STUDY OBJECTIVE: To evaluate the efficacy of darbepoetin alfa 200 microg subcutaneously every 2 weeks after therapeutic substitution for epoetin alfa. DESIGN: Retrospective multicenter chart review. SETTING: Three US Oncology-affiliated outpatient sites. PATIENTS: Three hundred thirty anemic patients with nonmyeloid malignancies, of whom 174 had been treated previously with epoetin alfa (switched group) and 156 had not been treated recently with epoetin alfa (naive group). INTERVENTIONS: Therapeutic substitution with darbepoetin alfa was started according to the US Oncology Pharmacy and Therapeutics Committee's recommended dosing guidelines: anemic patients with cancer received a starting dosage of darbepoetin alfa 200 microg every 2 weeks regardless of whether or not they had previously received epoetin alfa. Hematologic and darbepoetin alfa usage data were abstracted from consecutive medical records dated from May 2002-March 2003. MEASUREMENTS AND MAIN RESULTS: Median exposure to darbepoetin alfa was 10 weeks (25th quartile 6 wks, 75th quartile 17 wks) and 10 weeks (25th quartile 5 wks, 75th quartile 18 wks) for the naive and switched groups, respectively. The week before the switch to darbepoetin alfa, the 174 patients receiving epoetin alfa were administered the following weekly doses: less than 40,000 U (9%), 40,000 U (50%), or 45,000-90,000 U (41%). Mean hemoglobin level increased from baseline (wk 0) in both the naive and switched groups. The proportion of patients receiving a red blood cell transfusion in the darbepoetin alfa treatment phase was low (15% in each group). No variation in transfusion rates was observed across weight categories in patients who received a fixed dosage of darbepoetin alfa. Darbepoetin alfa was well tolerated. A detailed usage algorithm was validated by these results and is being used in these three US Oncology-affiliated practices. CONCLUSION: A darbepoetin alfa starting dosage of 200 microg subcutaneously every 2 weeks administered according to US Oncology-recommended dosing guidelines is effective in treating chemotherapy-induced anemia in both epoetin alfa-naive patients and those switched from epoetin alfa.     

Current and future options for the treatment of chemotherapy-induced anaemia

Chemotherapy-induced anaemia (CIA) is a significant source of morbidity in patients receiving treatment for cancer. There are three products currently available for the treatment of CIA: epoetin alfa, epoetin beta and darbepoetin alfa. Several organisations have published recommendations for the use of these agents. Several randomised, controlled trials have been conducted comparing the most popular dosing regimens of epoetin alfa and darbepoetin alfa, with conflicting results. Information regarding survival and adverse event data related to these agents continues to create debate. This review considers four new agents that are under development for the treatment of CIA.     

Current and future options for the treatment of chemotherapy-induced anaemia

Chemotherapy-induced anaemia (CIA) is a significant source of morbidity in patients receiving treatment for cancer. There are three products currently available for the treatment of CIA: epoetin alfa, epoetin beta and darbepoetin alfa. Several organisations have published recommendations for the use of these agents. Several randomised, controlled trials have been conducted comparing the most popular dosing regimens of epoetin alfa and darbepoetin alfa, with conflicting results. Information regarding survival and adverse event data related to these agents continues to create debate. This review considers four new agents that are under development for the treatment of CIA.     

Management of anaemia: a critical and systematic review of the cost effectiveness of erythropoiesis-stimulating agents

Erythropoiesis-stimulating agents (ESAs) are genetically engineered forms of erythropoietin that are used in the treatment of anaemia. Their successful use in the treatment of anaemia associated with renal disease, cancer and other diseases, as well as the development of multiple agents, has increased the visibility of these agents in the clinical and health economics literature. The circumstances under which the use of ESAs is cost effective, or indeed, whether it is cost effective, is of central concern for clinicians and payers who must make informed decisions regarding the management of these costly resources. Much of the recent literature on ESAs in the treatment of anaemia associated with chronic kidney disease and cancer, the two major therapeutic areas for ESA treatment, has focused on comparisons between individual ESAs, particularly epoetin alfa and darbepoetin alfa. While there have been some studies of cost effectiveness, many studies in these treatment areas have employed a cost-minimization approach and have relied on published prices rather than actual market prices. In general, this review of the literature suggests a cost advantage for epoetin alfa relative to darbepoetin alfa in the treatment of anaemia in renal and oncology indications. For other indications in which the literature is less developed, such as anaemia induced by antiviral therapy and blood management in surgery, small prospective studies or decision-analytic models comparing ESA therapy and standard care have been most common. Few conclusions can be drawn about the overall and relative costs or cost effectiveness of ESAs in these treatment areas.With the recent concerns about the safety of ESAs, especially when used outside the approved product labelling, future evaluations of epoetin alfa and darbepoetin alfa should factor their safety profiles into estimates of cost effectiveness. Moreover, additional studies are needed to evaluate whether the treatment of anaemia with ESAs is cost effective compared with no treatment or minimal blood transfusions, and whether the cost effectiveness of ESAs would be improved if ESA doses and durations were reduced.With the introduction of new longer-acting ESAs, such as the continuous erythropoietin receptor activator, the relative cost effectiveness among the different ESAs will continue to be an important question for public and private payers, policy makers and clinicians who must consider the emergence of new data and changing dosing patterns when making decisions about the use of these important but costly agents.     

Parenteral iron with erythropoiesis-stimulating agents for chemotherapy-induced anemia.

PURPOSE: To discuss the clinical issues we addressed in the development of our institutional guidelines regarding the assessment of iron stores for cancer- and treatment-related anemia and the administration of parenteral iron with erythropoiesis-stimulating agents (ESAs). DATA SOURCE: Studies published from January 1995 to August 2007 were identified by computer searches of Medline and hand searching of bibliographies of the articles identified via the computer searches. The current clinical practice guidelines were identified by computer searches of the web sites for national professional organizations that represent health care professionals who treat patients with cancer. RESULTS: of data analysis. Hematopoietic responses demonstrate that epoetin alfa and darbepoetin alfa provide similar outcomes for patients with chemotherapy-induced anemia (CIA); however, up to 50% of patients receiving these agents fail to adequately respond. Functional iron deficiency defined as a state of iron-restricted erythropoiesis is likely the primary contributor to the lack of response. Hematopoietic responses following ESA therapy with parenteral iron are substantially higher compared to response with no or oral iron. CONCLUSIONS: Iron stores should be assessed in all patients with cancer- or treatment-related anemia and parenteral iron should be administered to patients receiving ESA therapy to improve hematopoietic response. A unique algorithm that summarizes our institutional guidelines to assess iron stores and administer parenteral iron with ESA therapy in patients with CIA is included.     

Methoxy polyethylene glycol-epoetin beta: a review of its use in the management of anaemia associated with chronic kidney disease

Methoxy polyethylene glycol-epoetin beta (Mircera) is a continuous erythropoietin receptor activator, with a long half-life (approximately 130 hours). In patients with anaemia associated with chronic kidney disease (CKD), both on and not on dialysis, who had not previously received an erythropoiesis-stimulating agent (ESA), methoxy polyethylene glycol-epoetin beta administered intravenously or subcutaneously once every 2 weeks resulted in a smooth and steady rise in haemoglobin levels. The response rates were high (up to 97.5%) in these patients at the end of the correction period; response rates with the comparator ESAs (epoetin alfa or beta, or darbepoetin alfa) were up to 96.3%. Moreover, patients with CKD on dialysis who had previously been treated with an ESA maintained stable haemoglobin levels (within +/-1 g/dL of baseline and within a range of 10-13.5 g/dL) when directly converted to methoxy polyethylene glycol-epoetin beta administered intravenously or subcutaneously once every 2 or 4 weeks. Methoxy polyethylene glycol-epoetin beta is generally well tolerated, with most adverse events being of mild to moderate severity, consistent with the co-morbidities known to occur in this patient group and those reported with other ESAs. In conclusion, in patients with anaemia associated with CKD, subcutaneous or intravenous methoxy polyethylene glycol-epoetin beta achieved a high haemoglobin response rate (ESA-naive patients) when administered once every 2 weeks and maintained stable haemoglobin levels (patients previously treated with ESAs) when administered once monthly.     

Darbepoetin alfa: a review of its use in the treatment of anaemia in patients with cancer receiving chemotherapy

Darbepoetin alfa (Aranesp) is an analogue of recombinant human erythropoietin (rHuEPO) produced using recombinant DNA technology. The high number of sialic acid moieties in darbepoetin alfa results in a prolonged half-life and enhanced in vivo biological activity compared with rHuEPO (as demonstrated in animal studies) and permits a reduction in the frequency of administration.Subcutaneous darbepoetin alfa 2.25 microg/kg once weekly or 500 microg once every 3 weeks (with a provision for dose adjustments) is an effective and well tolerated erythropoietic agent in anaemic patients with cancer receiving chemotherapy. In randomised, controlled clinical trials, the drug increased haemoglobin levels and reduced the need for blood transfusions in patients with various types of nonmyeloid malignancies and also ameliorated anaemia-related fatigue, thereby improving their health-related quality of life (HR-QOL) scores. The once-every-3-weeks dosage regimen provides further convenience by offering the possibility of synchronising its administration with most chemotherapy regimens. Direct comparisons between approved dosages of darbepoetin alfa and other erythropoietic agents have not been conducted. Such comparisons would be very helpful in formulating definitive conclusions about their relative efficacy and cost effectiveness. Darbepoetin alfa provides an effective and well tolerated treatment option for the treatment of anaemia in patients with cancer receiving chemotherapy.     

Development and evaluation of a population pharmacokinetic-pharmacodynamic model of darbepoetin alfa in patients with nonmyeloid malignancies undergoing multicycle chemotherapy

Anemia is frequently observed in patients undergoing chemotherapy. Administration of darbepoetin alfa, a recombinant erythropoiesis-stimulating agent that has longer residence time than endogenous erythropoietin, to patients with chemotherapy-induced anemia (CIA) increases mean hemoglobin concentration, reduces risk of red blood cell transfusions, and improves patient-reported outcomes. A pharmacokinetic/pharmacodynamic (PkPd) model was developed using data from patients with nonmyeloid malignancies and CIA who were receiving darbepoetin alfa. A 2-compartment Pk model with linear elimination described the Pk data obtained in 140 CIA patients after intravenous and subcutaneous (s.c.) doses of 2.25 microg/kg every week and s.c. doses of 6.75 microg/kg every 3 weeks. The population typical values of key Pk parameters were clearance, 2010 mL/day; steady-state volume of distribution, 3390 mL; and bioavailability, 44.3%. A modified indirect response model, wherein serum concentrations stimulated the production of hemoglobin through an Emax-type equation, described the hemoglobin levels after s.c. doses of 0.5 microg/kg every week to 15 microg/kg every 3 weeks in 573 CIA patients. The estimated incremental maximum stimulation of hemoglobin production was 43.7% and darbepoetin alfa serum concentration at half-maximal stimulation was 3.68 ng/mL. The impact of covariates (body weight and platinum-containing chemotherapy) on the PkPd response was evaluated based on point and interval estimates of parameters, rather than through stepwise hypothesis testing. The final PkPd model adequately predicted hemoglobin response in a test data set, thereby confirming the predictive capability of the model. Based on simulations, it was not possible to categorize the influence of any covariate as clinically important.     

Chemotherapy-induced anemia: the story of darbepoetin alfa

Abstract

Background:

Prior to the approval of the first erythropoiesis-stimulating agent (ESA) in the early 1990s, red blood cell transfusions were the primary means of treating severe chemotherapy-induced anemia (CIA), with little recourse for those with more mild forms of the condition. The introduction of the ESAs allowed treatment of mild-to-moderate CIA in patients with cancer. It has been a decade since darbepoetin alfa (DA), a second-generation ESA with a longer half-life, became available to patients with CIA.     

Darbepoetin alfa for anemia in chronic kidney disease

Anemia of chronic kidney disease (CKD) is common, yet it is often under-recognized and undertreated, with serious adverse consequences. It is highly responsive to treatment with erythropoiesis-stimulating agents (ESAs). Darbepoetin alfa is a hyperglycosylated ESA that has a lower affinity to the erythropoietin receptor but a longer half-life than recombinant human erythropoietin, irrespective of administration by a subcutaneous or intravenous route. Owing to its pharmacokinetic characteristics, darbepoetin alfa has been used in extended dosing intervals ranging from once every week to once every 4 weeks in CKD patients on dialysis, as well as in CKD patients not on dialysis. Darbepoetin alfa has been shown to be safe and effective in clinical trials. The safety profile of darbepoetin alfa is similar to that of recombinant human erythropoietin. While target hemoglobin levels in CKD anemia remain debatable, treatment of anemia with ESAs has the proven benefits of reducing transfusions and improving quality of life. Darbepoetin alfa has the potential to simplify the treatment of CKD anemia with many advantages, including infrequent dosing, improved patient convenience and compliance, and decreased healthcare resource utilization.     

Guidelines and recommendations for the management of anaemia in patients with lymphoid malignancies

Patients with lymphoid malignancies frequently require repetitive and intensive anticancer treatments to induce and maintain disease remission. Anaemia (haemoglobin [Hb] <12 g/dL) is a common and debilitating problem associated with both the malignancy itself and its treatment burden. Anaemia negatively impacts on all aspects of patient quality of life (QOL) and treatment outcomes and survival, particularly in this disease setting.Widely acknowledged goals of anaemia treatment include Hb correction to approximately 12 g/dL, reduction in transfusion requirements and optimisation of patient QOL. Since the introduction of recombinant human erythropoietic therapy, transfusion (once the only anaemia treatment option available) is now primarily reserved for non-responders or those with severe or life-threatening anaemia. Data from randomised, double-blind, placebo-controlled studies, and large, non-randomised, open-label, community-based studies, along with almost 15 years of practical experience, support the assertion that epoetin alfa administered at a dosage of 150-300 U/kg three times weekly or 40,000-60,000U once weekly, both of which are US FDA-approved dose administration schedules, can effectively and safely achieve anaemia treatment goals for the majority of patients with lymphoid malignancies. Data and practical experience collected over the last 5 years on another erythropoietic agent with a slightly longer half-life but lower binding affinity, darbepoetin alfa, show that this agent when administered according to the FDA-approved dose administration schedules (2.25-4.5 microg/kg once weekly or 500microg once every 3 weeks) or according to a commonly-administered dose in clinical practice (3.0-5.0 microg/kg once every 2 weeks) can also effectively and safely correct anaemia, reduce transfusion requirements and improve QOL in many patients with lymphoid malignancies. One comparative head-to-head trial suggested that epoetin alfa might be superior to darbepoetin alfa in anaemic cancer patients receiving chemotherapy with respect to timing and magnitude of Hb correction, although further study is necessary, especially concerning optimal dose administration. Alternative dose administration schedules, such as epoetin alfa 80,000U every 2 weeks from initiation or 80,000U every 3 weeks following initiation with once weekly administration and darbepoetin alfa 4.5 microg/kg every 3 weeks following initiation with once weekly administration, are being actively investigated with the goal of increased flexibility for patients and healthcare providers.The treatment of anaemia in patients with lymphoid malignancies is an important part of overall disease management, as evidenced by continuous investigation of existing erythropoietic agents and new agents. Although treatment guidelines issued by organisations such as the National Comprehensive Cancer Network (NCCN) and American Society of Hematology (ASH)/American Society of Clinical Oncology (ASCO) suggest intervention with erythropoietic therapy when Hb falls below 10-11 g/dL or based on clinical symptoms, data suggest that anaemia is vastly under-recognised and under-treated. Clearly, an update on the definition, identification and optimal management of anaemia in patients with lymphoid malignancies is warranted.     

Economic evaluation of weekly epoetin alfa versus biweekly darbepoetin alfa for chemotherapy-induced anaemia: evidence from a 16-week randomised trial

INTRODUCTION: A 16-week, open-label, multicentre, randomised trial of weekly epoetin alfa 40 000 units versus biweekly darbepoetin alfa 200microg among 358 patients with solid-tumour cancers and chemotherapy-induced anaemia demonstrated superior haematological outcomes with epoetin alfa. We sought to compare resource use, costs and clinical outcomes between treatment groups and report the results using a cost-consequences framework. METHODS: Pre-specified methods were used to assign costs (US dollars, year 2004-5 values) to medical resources and patient time using a societal perspective. Costs for inpatient care, outpatient care and physician services were based on US Medicare reimbursement rates. Indirect costs assigned to patient time spent receiving study medication were based on the mean hourly wage in the US. In the base-case analysis, the average wholesale price was used to assign costs to medications. Clinical outcomes included all haemoglobin levels and transfusions recorded throughout the trial. Sensitivity analyses were performed to evaluate the impact of different costing methods, cost sources, perspectives and methods to assign haemoglobin values following a blood transfusion. RESULTS: Over a mean follow-up duration of 11.8 weeks, the average cost of study medications and their administration was the single largest component of total costs and was similar between groups (epoetin alfa 5979 US dollars and darbepoetin alfa 5935 US dollars, difference 44 US dollars; 95% CI -590, 692). There were no significant differences in the proportions of patients hospitalised (epoetin alfa 24.6%, darbepoetin alfa 22.0%; p = 0.57). Patients randomised to epoetin alfa experienced more inpatient days, on average, than patients randomised to darbepoetin alfa (2.6 vs 1.6, 95% CI for the difference, 0.07, 2.27). However, with regard to transfusions, patients in the epoetin alfa arm required fewer units of blood than patients in the darbepoetin alfa arm (0.46 vs 0.88, 95% CI for the difference -0.77, -0.08). Mean total costs, comprising costs for study medications and their administration, inpatient care, transfusions, unplanned radiation therapy, haematology and laboratory services, chemotherapy and non-chemotherapy drugs and indirect costs were 14,976 US dollars in the epoetin alfa arm compared with 14,101 US dollars in the darbepoetin alfa arm, a difference of 875 US dollars (95% CI for difference -849, 2607), of which 98% of the difference was attributable to higher inpatient costs in the epoetin alfa arm (2374 US dollars vs 1520 US dollars; 95% CI for difference -33, 1955). Assessments of multiple clinical measures demonstrated improved outcomes with epoetin alfa relative to darbepoetin alfa. CONCLUSION: Most clinical outcome measures suggested greater improvement with epoetin alfa relative to darbepoetin alfa, but most costs for both agents appeared similar. Decision makers must evaluate the differences in costs and efficacy measures that are most relevant from their perspectives.     

Darbepoetin alfa: new indication/new dosage. No proven advantage in chemotherapy-induced anaemia

(1) Current treatments for anaemia in patients receiving cancer chemotherapy include blood transfusion and epoetin alfa and beta. These epoetins correct anaemia in 40% to 65% of patients and reduce the number of patients who require transfusions during the second and third months of treatment by 12-35% in absolute terms. (2) Darbepoetin alfa is slightly more glycosylated than epoetin alfa and beta. It is no more effective than these two drugs in chronic renal failure. Darbepoetin alfa is now approved for the treatment of anaemia in patients who are receiving chemotherapy for non myeloid malignancies. (3) Two placebo-controlled dose-finding studies and two placebo-controlled trials involving nearly 1000 patients in total have shown that darbepoetin alfa decreases the number of transfused patients by 17-25% in absolute terms, and that it probably reduces fatigue. However, one-quarter of patients receiving darbepoetin were nonetheless transfused. (4) In the absence of reliable comparisons, there is no firm evidence that darbepoetin alfa is more effective than other epoetins. (5) According to relatively imprecise company reports, darbepoetin alfa increased the risk of thromboembolic events during clinical trials (6% versus 3%), including pulmonary embolism (1.3% versus 0%); the company also states that darbepoetin alfa does not increase the risk of arterial hypertension, a classical effect of epoetin that is mentioned in the summary of product characteristics (SPC). Placebo-controlled trials and dose-finding studies show no impact on the outcome of cancer, but follow-up is limited and a negative effect cannot be ruled out. The company states that no cases of erythroblastopenia have occurred among more than 70 000 treated patients. (6) According to the SPC, darbepoetin alfa can be given once a week. However, the optimal epoetin dosing schedule is unknown. Epoetin therapy takes several weeks to correct anaemia, whereas transfusion is immediately effective. (7) In practice, darbepoetin alfa seems a little easier to administer than epoetin alfa or beta, but the advantages and disadvantages of these drugs as compared with blood transfusion are not entirely clear.     

Darbepoetin alfa: a novel erythropoiesis-stimulating protein

Darbepoetin alfa is a novel erythropoiesis-stimulating protein developed for the treatment of anemia. It is a hyperglycosylated analog of recombinant human erythropoietin with the same mechanism of action as erythropoietin, but with a three-fold longer terminal half-life after intravenous administration than recombinant human erythropoietin and the native hormone both in animal models and in humans. Clinical studies in patients with chronic renal failure either receiving or not receiving dialysis have shown that darbepoetin alfa is equivalent to recombinant human erythropoietin in terms of increases in hemoglobin concentration, percentage of patients achieving target hemoglobin concentration and average time to reach target hemoglobin concentration, although darbepoetin alfa is administered less frequently (once weekly or every other week). Clinical trials in cancer patients either receiving or not receiving chemotherapy have demonstrated that darbepoetin alfa is safe and effective in alleviating anemia at dose intervals of once every 1, 2 or 3 weeks, and results suggest that it may achieve greater and more rapid responses than recombinant human erythropoietin in cancer patients. Furthermore, an improvement in health-related quality of life has been observed in association with anemia correction using darbepoetin alfa therapy in these patients. Darbepoetin alfa has been approved for intravenous and subcutaneous administration by the European Commission and the FDA for the treatment of anemia in patients with chronic renal failure. Additionally, this product was recently approved by the FDA for the treatment of anemia in patients with nonmyeloid malignancies where anemia is due to the effect of concomitantly administered chemotherapy. The recommended starting dose in chronic renal failure patients is 0.45 microg/kg once weekly for both intravenous and subcutaneous administration, with subsequent titration based on the hemoglobin concentration. In cancer patients, the recommended starting dose is 2.25 microg/kg once weekly by subcutaneous injection and subsequent titration. The adverse event profile of darbepoetin alfa is similar to that of recombinant human erythropoietin in both settings. There are no reports of antibody formation associated with darbepoetin alfa in chronic renal failure patients, and three cases of antibody formation, with neutralizing activity in one of the cases, have been reported in cancer patients. However, no cases of antibody-mediated pure red cell aplasia have been reported. The longer half-life of darbepoetin alfa, together with a similar efficacy and safety profile, confers the clinical advantage over recombinant human erythropoietin of allowing a less frequent dosing (once weekly or every other week versus one to three times weekly in renal patients), thus reducing health-care utilization and probably improving patient compliance.     

Darbepoetin alfa: an effective treatment with flexible and simplified dosing for anemia in patients with cancer

Anemia is common in patients with cancer or myelodysplastic syndrome. Erythropoietic therapy offers an effective way to manage anemia by increasing hemoglobin levels, decreasing transfusion requirements, and alleviating symptoms. We reviewed data showing the feasibility and effectiveness of treatment with the erythropoiesis-stimulating protein darbepoetin alfa at extended dosing intervals to treat anemia in patients with cancer receiving multicycle chemotherapy. We also explored the darbepoetin alfa's potential for treating anemia in patients with myelodysplastic syndrome. Data from clinical studies and drug therapy evaluations confirm that darbepoetin alfa administered weekly, every 2 weeks, and every 3 weeks corrects and maintains hemoglobin levels in patients with chemotherapy-induced anemia. In addition, the data demonstrate that both weight-based and fixed dosing with darbepoetin alfa are effective, and that early intervention to treat anemia has clinical benefits. Darbepoetin alfa also is an effective treatment for anemia in patients with cancer not receiving chemotherapy, at extended dosing intervals of at least 3 weeks. Extended dosing for anemia treatment can provide benefits for patients, caregivers, and clinicians because it reduces the number of clinic visits needed and permits synchronizing anemia treatment with chemotherapy cycles. Data from recent studies suggest that darbepoetin alfa is effective for treating anemia in patients with myelodysplastic syndrome; this potential use is being investigated further in ongoing studies. Thus, darbepoetin alfa is an attractive therapy option for patients with chemotherapy or cancer-induced anemia. It allows increased flexibility and simplified dosing and may offer some benefit in the treatment of anemia in patients with myelodysplastic syndrome.     

Cost-minimization analysis of darbepoetin alfa versus epoetin alfa in the hospital setting.

PURPOSE: The cost of darbepoetin alfa versus that of epoetin alfa in a hospital setting was studied. METHODS: The study was an observational, retrospective review of the hospitalwide use of darbepoetin and epoetin during hospital admissions beginning in the period from January 2003 through April 2003. After the identification from daily charge reports of patients who used at least one of the study drugs during an admission, charts were requested for review. Drug product costs were determined from hospital purchasing information. Material and labor costs were combined to estimate drug administration costs. Total costs were calculated as the sum of drug product costs and administration costs. RESULTS: A total of 429 epoetin records and 80 darbepoetin records were included. The two cohorts were similar with respect to demographic characteristics. With respect to costs, the only significant difference between cohorts was in daily administration costs, which were lower for patients receiving darbepoetin. Sensitivity analysis found lower costs for darbepoetin only after the dose-conversion ratio (DCR) was increased to above 256.74 units:1 microg. The overall DCR based on the median daily dose of each drug was 244.90 units:1 microg. CONCLUSION: A cost-minimization study in a hospital showed no cost difference between treatment with epoetin and darbepoetin.     

Pharmacotherapy of kidney stones

Background: Since their inception nearly two decades ago, erythropoietin-stimulating agents (ESAs) have revolutionized the care of patients with renal anemia. Until recently, treatment options included the epoetins and darbepoetin alfa. As the use of these agents for chronic kidney disease (CKD) became widespread, the introduction of ESAs – touted for their longer-acting properties – was excitedly anticipated. Objectives: To review the option of methoxy polyethylene glycol-epoetin beta for ESA therapy in patients with renal anemia. Methods: Peer-reviewed scientific literature, published abstracts and renal business journals were reviewed in the writing of this opinion. Results/conclusion: Methoxy polyethylene glycol-epoetin beta (CERA) is an effective long-acting ESA approved for treatment of renal anemia and available for use outside of the United States. CERA corrects and maintains hemoglobin (Hb) levels in patients with CKD and its efficacy mirrors that of the epoetins and darbepoetin alfa. CERA holds promise for its safety record, administration requirements, and the potential impact on social and pharmacoeconomic barriers to treatment for patients with renal anemia.     

The relative dosing of epoetin alfa and darbepoetin alfa in chronic kidney disease

ABSTRACT

Objective: The purpose of this study was to review and analyze current research to evaluate the dose ratio of epoetin alfa and darbepoetin alfa for the treatment of anemia in chronic kidney disease (CKD) and to identify determinants of the variation in epoetin alfa: darbepoetin alfa dose ratios across studies.

Methods: A systematic review of the literature for comparative switch and non-switch studies of epoetin alfa and darbepoetin alfa treatments in CKD for the period 2000–2005 was performed. Two reviewers independently assessed the quality of the information. Data on the study design and outcomes were collected for each selected study. The dose ratio from epoetin alfa to darbepoetin alfa was calculated for each study, and the results were reported stratified by study characteristics. To control for differences in study design and characteristics that could explain the variability in the relative dosages of the two agents across studies, multivariate regression analysis was conducted. Based on these results, a dose conversion ratio for Canada was estimated.

Results: A total of 21 studies involving 16?378 patients exposed to epoetin alfa or darbepoetin alfa in CKD were identified. Univariate analysis of the dose ratios indicated a mean dose ratio of 217:1 (IU of epoetin alfa:µg of darbepoetin alfa). Results from the multivariate analysis demonstrated that the study design (i.e., switch study versus straight comparison studies) and geographical coverage (i.e., United States) affected the results. Based on the multivariate analysis, the dose conversion ratio between epoetin alfa and darbepoetin alfa for Canada was 169:1.

Conclusions: Despite limitations associated with switching studies and the limited total number of studies available, this systematic review based on aggregated results provides further evidence to the clinical community that the dose conversion ratio for epoetin alfa:darbepoetin alfa in CKD patients in Canada is approximately 169:1. At that ratio, treatment with epoetin alfa is 11–18% cheaper than treatment with darbepoetin alfa in Canada.     

Dose and cost comparison of erythropoietic agents in the inpatient hospital setting.

PURPOSE: The inpatient dosing patterns and treatment costs in cancer and predialysis chronic kidney disease (CKD) patients treated with erythropoietic agents from a hospital pharmacy perspective were studied. METHODS: An analysis of electronic inpatient records from the Premier Perspective comparative hospital database was conducted. Study participants were identified through hospitalizations recorded between July 2002 and March 2005 from over 500 hospitals nationwide. Adult patients with an admitting diagnosis of cancer or predialysis CKD and treated with epoetin alfa or darbepoetin alfa during hospitalization were included. Patients who had received renal dialysis or both agents during a hospitalization were excluded. Wholesale acquisition costs from September 2006 were used to calculate drug costs. RESULTS: A total of 25,645 hospitalized patients with cancer (22,873 received epoetin alfa; 2,772 received darbepoetin alfa) and 66,822 hospitalized patients with CKD (60,079 received epoetin alfa; 6,743 received darbepoetin alfa) were identified. The mean cumulative dose per hospitalization resulted in dose ratios of 245:1 and 242:1 (units epoetin alfa:micrograms darbepoetin alfa) for cancer and CKD patients, respectively. On the basis of the cumulative dose per hospitalization, drug costs for darbepoetin alfa-treated patients were approximately 50% higher than drug costs for epoetin alfa-treated patients for both oncology and CKD patients. CONCLUSION: Epoetin alfa was associated with less cost compared with darbepoetin alfa for treating inpatients with cancer or CKD. Further research including the patients' clinical outcomes is necessary to determine the true pharmacoeconomic differences between the two agents.