Over 5 years of darbepoetin alfa: two case histories

Anaemia is one of the most serious complications of renal dysfunction and is associated with severe, often life-threatening clinical sequelae including cardiovascular disease [1]. Anaemia of renal insufficiency originates from a reduced ability of the kidney to produce the protein hormone erythropoietin (EPO), which is responsible for the initiation of red blood cell (RBC) production from precursor cells produced by the bone marrow. Currently, European Best Practice Guidelines for the Management of Anaemia in Patients with Chronic Renal Failure recommend that treatment of renal anaemia should be achieved by the supplementation of endogenous EPO with recombinant human EPO (rHuEPO), which stimulates erythropoiesis, thereby inducing a rise in haemoglobin (Hb) concentrations [2]. Usually, rHuEPO therapy is given two or three times per week and can be administered by the intravenous or subcutaneous routes in patients undergoing haemodialysis (HD) or subcutaneously in patients receiving peritoneal dialysis (PD). Darbepoetin alfa (Aranesp, Amgen, Inc.) is an erythropoiesis-stimulating protein that is molecularly distinct from rHuEPO. It is super-sialated, which leads to a longer serum half-life than that of rHuEPO [3,4], resulting in extended in vivo erythropoietic activity. Darbepoetin alfa can be given less frequently and can be used subcutaneously or intravenously with the same, or equivalent Hb responses and dosing [7], offering simplified dosing for new patients and those currently treated with rHuEPO. Clinical trials with darbepoetin alfa began in 1997 and this brief article reports on two patients whose long-term anaemia management has been simplified by its use.     

The advantages of intravenous renal anaemia treatment in an undernourished patient with chronic kidney disease

SUMMARY

The subcutaneous (SC) treatment of renal anaemia in undernourished patients has potential limitations. In this case report we demonstrate the value of intravenous (IV) darbepoetin alfa in such a patient who experienced difficulty tolerating SC recombinant human erythropoietin (rHuEPO) therapy due to severe malnutrition. Intravenous treatment of renal anaemia in a malnourished patient is preferred because the absence of SC fat makes SC administration difficult. In such patients, darbepoetin alfa is the treatment of choice as it is administered less frequently than other erythropoietic therapies and yis more effective at maintaining target haemoglobin (Hb) concentrations. In contrast to rHuEPO, darbepoetin alfa also has the additional advantage of bioequivalent IV and SC dose requirements.     

The advantages of intravenous renal anaemia treatment in an undernourished patient with chronic kidney disease

The subcutaneous (SC) treatment of renal anaemia in undernourished patients has potential limitations. In this case report we demonstrate the value of intravenous (IV) darbepoetin alfa in such a patient who experienced difficulty tolerating SC recombinant human erythropoietin (rHuEPO) therapy due to severe malnutrition. Intravenous treatment of renal anaemia in a malnourished patient is preferred because the absence of SC fat makes SC administration difficult. In such patients, darbepoetin alfa is the treatment of choice as it is administered less frequently than other erythropoietic therapies and is more effective at maintaining target haemoglobin (Hb) concentrations. In contrast to rHuEPO, darbepoetin alfa also has the additional advantage of bioequivalent IV and SC dose requirements.     

Effects of salicylate and other enhancers on rectal absorption of erythropoietin in rats.

To develop a new treatment for patients with anaemia in which erythropoietin (EPO) can be given without injection, the effects of promoters of the rectal absorption of EPO were studied. Recombinant human (rHu) EPO (5000 units) in a dosing solution or in a rectal suppository was placed in the rectum of healthy rats and changes in serum EPO levels were monitored by an enzyme-linked immunosorbent assay. Without a promoter, rHuEPO was not absorbed. Sodium glycocholate, sodium caprate, and sodium salicylate in the solution of rHuEPO increased the absorption of rHuEPO. Sodium salicylate or sodium caprate in the suppository with rHuEPO also increased its absorption. The bioavailability of rHuEPO in a suppository containing 5% sodium salicylate compared with that by an intravenous injection was 1.2%. rHuEPO given in rectal suppositories containing sodium salicylate and inserted once a day for 6 consecutive days increased erythropoiesis in peripheral blood.     

Epoetins and [symbol: see text] darbepoetin alfa in malignant disease

Anaemia is common in people with cancer, and may reduce their quality of life and life expectancy. Blood transfusion can increase haemoglobin levels but is usually reserved for those with moderate anaemia (haemoglobin level below 10 g/dL). A potential alternative is treatment with one of the human recombinant forms of erythropoietin, epoetin alfa (Eprex--Janssen-Cilag) or epoetin beta (NeoRecormon--Roche), or their hyperglycosylated derivative [symbol: see text] darbepoetin alfa (Aranesp--Amgen). These products have improved the management of patients with chronic renal failure who are anaemic. Here we assess the place of the epoetins and darbepoetin alfa in managing anaemia in patients with cancer.     

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.     

The impact of anaemia and its treatment on employee disability and medical costs

OBJECTIVE: Anaemia is a common haematological complication of cancer and cytotoxic treatment. The incremental economic burden associated with medical care and short-term disability of anaemia in patients with malignancy and receiving chemotherapy has not been well documented. This study evaluates the effect of anaemia on the costs associated with cancer treated with chemotherapy. METHODS: Patients receiving chemotherapy within 6 months of their initial cancer diagnosis were identified in a commercial claims database for 1999-2000. Data for these individuals were linked to their employers' short-term disability records via unique encrypted personal identification numbers provided by employers. Patients with anaemia were identified by a diagnosis of anaemia or treatment with transfusion or erythropoietin alfa (EPO). Healthcare expenditure and short-term disability leave were observed for up to 6 months following initial cancer diagnosis and were summarised into monthly averages. Exponential conditional mean models and zero-inflated negative binomial models were used to analyse mean monthly healthcare expenditures and short-term disability days. RESULTS: Twenty-five percent of the 619 newly diagnosed cancer patients treated with chemotherapy had anaemia. The presence of anaemia and longer length of transfusion therapy were associated with increased expenditures, while longer length of EPO treatment was associated with lower expenditures. The incremental costs due to anaemia among patients receiving chemotherapy were US$5,538 (year 2001 values) per month in the first 6 months following cancer diagnosis, 10.8% of which were costs related to short-term disability leave. CONCLUSION: Anaemia in patients undergoing chemotherapy presents a substantial burden to employers and payers. The findings also suggest that patients with anaemia treated with erythropoietin alfa can achieve expenditure levels similar to those patients without anaemia.     

Dosing patterns, hematologic outcomes, and costs of erythropoietic agents in predialysis chronic kidney disease patients with anemia

OBJECTIVE: Few observational studies have evaluated the use of epoetin alfa (EPO) and darbepoetin alfa (DARB) in chronic kidney disease (CKD) patients with anemia. The objective of this study was to investigate dosing patterns, hematologic outcomes, and intervention costs with EPO and DARB in anemic CKD patients treated in an ambulatory care setting. METHODS: This was a multicenter, retrospective, chart review of predialysis CKD patients with anemia treated with EPO or DARB. Charts were sequentially selected from 435 EPO and 432 DARB patients naive to erythropoietic therapy and treated for > or = 24 weeks. Hemoglobin (Hb) levels, dates, and EPO/DARB doses were recorded. Drug costs using 2005 wholesale acquisition costs (WAC) and Federal Supply Schedule (FSS) pricing were based on the mean cumulative drug dose over the 24-week study period. RESULTS: A total of 393 EPO and 396 DARB charts met all criteria with predominantly male subjects (EPO: 94%; DARB: 96%). Mean baseline GFR and Hb levels were similar. Once-weekly and extended dosing (> or = Q2W) was common in both groups. At Weeks 4, 8, and 12 following initiation of therapy, a greater proportion of EPO than DARB patients reached target Hb levels (> or = 11 g/dL) (p < 0.0001); at Week 24, all patients reached target Hb levels. Mean 24-week cumulative doses were EPO 279 336 +/- 68 302 units and DARB 1084 +/- 246 microg. Drug cost was higher for DARB independent of pricing utilized (WAC: EPO = 3400 US dollars, DARB = 4726 US dollars; FSS: EPO = 1528 US dollars, DARB = 2379 US dollars). CONCLUSIONS: Extended dosing (Q2W) was common in EPO- and DARB-treated patients with CKD-related anemia, with EPO-treated patients experiencing a significantly greater hematologic response (at Weeks 4, 8, and 12). In addition, drug cost was 39-56% higher in the DARB group. The male predominance may limit generalizability, warranting further research in other populations.     

Investigation of the effects of altered receptor binding activity on the clearance of erythropoiesis-stimulating proteins: Nonerythropoietin receptor-mediated pathways may play a major role

Erythropoietin (EPO) receptor-mediated endocytosis and degradation in the bone marrow has been hypothesized to be the major clearance pathway of erythropoiesis-stimulating agents (ESA). We investigated the role of this pathway in ESA clearance by determining the pharmacokinetic profiles after intravenous (IV) dosing in rats and mice of recombinant human EPO (rHuEPO) and rHuEPO derivatives with different receptor binding activities and biochemical properties. These derivatives included NM385 (no detectable receptor binding activity), hyperglycosylated analogs with different carbohydrate contents and receptor binding activities; (NM294: +1 carbohydrate chain; darbepoetin alfa: +2 carbohydrate chains) and polyethylene glycol (PEG) derivatives (PEG-darbepoetin alfa, PEG-rHuEPO and PEG-NM385). After IV administration in rats, NM385 had a mean clearance (CL) similar to rHuEPO. Hyperglycosylated ESAs, compared with rHuEPO, had a progressively longer half-life (t(1/2)) and a progressively slower CL with increasing number of carbohydrates or amount of added PEG that correlated more closely with carbohydrate and/or PEG content than receptor binding activity. Taken together, these results suggest that (1) EPO receptor-independent pathway(s) play a substantial role in ESA clearance; (2) the longer half-life and reduced clearance of hyperglycosylated and/or PEGylated ESAs are primarily the result of decreased susceptibility to receptor-independent elimination mechanisms.     

Retrospective observational study of patients with chemotherapy-related anemia receiving erythropoietic agents

OBJECTIVE: Epoetin alfa (EPO) and darbepoetin alfa (DARB) are approved for the treatment of chemotherapy-related anemia (CRA) in patients with nonmyeloid malignancies. This study examined dosing and hematologic outcomes with these agents in community oncology clinics. METHODS: Medical charts were abstracted retrospectively for 1005 patients (527 EPO, 478 DARB) with CRA (hemoglobin [Hb] < or = 11 g/dL) who received EPO or DARB at 10 U.S. oncology clinics between January 2002 and March 2003. MAIN OUTCOME MEASURES: Outcome measures included dose and frequency of erythropoietic therapy, change in Hb at 4, 8, and 12 weeks after initiation of therapy, and transfusion of packed red blood cells. RESULTS: Baseline characteristics were generally similar between groups. Most EPO-treated patients received EPO once weekly, but 25% received EPO every 2-3 weeks, with 40,000 U the predominant dose. DARB was usually given every 1-2 weeks in doses ranging from 200-400 mcg/injection. Mean treatment duration was relatively short (< 8 weeks) in both groups, with a similar number of Hb determinations and similar incidence of red blood transfusion between groups. Hb increased from baseline in the EPO and DARB groups at 4 weeks (0.99 vs. 0.69 g/dL, p = 0.003), 8 weeks (1.39 vs. 1.06 g/dL, p = 0.011), and 12 weeks (1.43 vs. 1.11 g/dL, p = 0.055). Early Hb response (> or = 1 g/dL increase by 4 weeks) was more common with EPO than DARB (48% vs. 38%, p = 0.008). CONCLUSIONS: EPO was superior to DARB for early hematologic outcomes in patients with CRA in community oncology clinics. Retrospective data collection and relative inexperience with DARB at the time of the study may limit the generalization of these results. Randomized, controlled trials comparing EPO and DARB are warranted.     

Darbepoetin alfa.

Darbepoetin alfa is a novel erythropoiesis-stimulating protein developed for the treatment of anaemia associated with chronic kidney disease. In single-dose studies in patients undergoing dialysis, the mean terminal half-life for intravenous darbepoetin alfa was approximately 3-fold longer than for intravenous recombinant human erythropoitin (r-HuEPO, epoetin alfa; 25.3 vs 8.5 hours). The mean terminal half-life after subcutaneous administration of darbepoetin alfa was 48.8 hours. In randomised nonblind trials in patients undergoing dialysis, darbepoetin alfa (0.45 pg/kg) given once weekly for the correction of anaemia increased haemoglobin (Hb) levels to a similar extent as darbepoetin alfa three times weekly or r-HuEPO two or three times weekly. A double-blind, randomised clinical trial reported that switching patients from a three-times weekly regimen of r-HuEPO to once weekly darbepoetin alfa with additional placebo twice weekly (all intravenously) maintained Hb levels between 9.0 and 13.0 g/dl to a similar extent as continued treatment with r-HuEPO three times weekly. In a randomised nonblind study, r-HuEPO-naive patients with chronic renal insufficiency received either subcutaneous darbepoetin alfa once weekly or r-HuEPO twice weekly. 93% of patients receiving darbepoetin alfa and 92% of patients receiving r-HuEPO achieved a Hb increase of > or = 1.0 g/dl from baseline and the mean increase in Hb level over the initial 4 weeks was similar for both treatments. The number and frequency of adverse events, withdrawals and deaths reported in clinical trials did not differ between patients receiving darbepoetin alfa and patients receiving r-HuEPO. There have been no reports of immune responses to darbepoetin alfa in 1534 patients receiving treatment for up to 2 years.     

Dosing patterns,hematologic outcomes,and costs of erythropoietic agents in predialysis chronic kidney disease patients with anemia

ABSTRACT

Objective: Few observational studies have evaluated the use of epoetin alfa (EPO) and darbepoetin alfa (DARB) in chronic kidney disease (CKD) patients with anemia. The objective of this study was to investigate dosing patterns, hematologic outcomes, and intervention costs with EPO and DARB in anemic CKD patients treated in an ambulatory care setting.

Methods: This was a multicenter, retrospective, chart review of predialysis CKD patients with anemia treated with EPO or DARB. Charts were sequentially selected from 435 EPO and 432 DARB patients naive to erythropoietic therapy and treated for ≥ 24 weeks. Hemoglobin (Hb) levels, dates, and EPO/DARB doses were recorded. Drug costs using 2005 wholesale acquisition costs (WAC) and Federal Supply Schedule (FSS) pricing were based on the mean cumulative drug dose over the 24‐week study period.

Results: A total of 393 EPO and 396 DARB charts met all criteria with predominantly male subjects (EPO: 94%; DARB: 96%). Mean baseline GFR and Hb levels were similar. Once-weekly and extended dosing (≥ Q2W) was common in both groups. At Weeks 4, 8, and 12 following initiation of therapy, a greater proportion of EPO than DARB patients reached target Hb levels (≥ 11?g/dL) (?p < 0.0001); at Week 24, all patients reached target Hb levels. Mean 24‐week cumulative doses were EPO 279?336 ± 68?302 units and DARB 1084 ± 246?µg. Drug cost was higher for DARB independent of pricing utilized (WAC: EPO = $3400, DARB = $4726; FSS: EPO = $1528, DARB = $2379).

Conclusions: Extended dosing (≥ Q2W) was common in EPO- and DARB-treated patients with CKD-related anemia, with EPO-treated patients experiencing a significantly greater hematologic response (at Weeks 4, 8, and 12). In addition, drug cost was 39–56% higher in the DARB group. The male predominance may limit generalizability, warranting further research in other populations.     

Epoetin alfa for the treatment of cancer- and chemotherapy-related anaemia: product review and update

Anaemia, often associated with chemotherapy, is a common and debilitating disorder in cancer patients. Recombinant human erythropoietin (epoetin alfa) was introduced in the 1990s for the treatment of chemotherapy-related anaemia. Data from randomised, double-blind, placebo-controlled studies and large, non-randomised, community-based studies have demonstrated that either of the FDA-approved dosing schedules of epoetin alfa 150 - 300 U/kg three times weekly or 40,000-60,000 U/week s.c., significantly increases haemoglobin levels, reduces transfusion requirements, and improves quality of life in anaemic cancer patients undergoing chemotherapy or chemoradiation therapy. Guidelines for the effective and safe use of epoetin alfa have been published by major oncology/haematology organisations and are reviewed in this article. Areas of recent and ongoing investigation with epoetin alfa are also covered in this review.     

Cost-minimization analysis of once-weekly versus thrice-weekly epoetin alfa for chemotherapy-related anemia

BACKGROUND: For individuals with chemotherapy-related anemia, the clinical effectiveness of epoetin alfa (EPO) dosed once weekly ([QW], 40,000 units per dose) has been demonstrated to be indistinguishable from that observed with thrice-weekly dosing ([TIW], 10,000 units per dose). Whether the advantage of less-frequent administration justifies the higher EPO dosage used in the weekly regimen in terms of overall cost of care is unknown. OBJECTIVE: To conduct a cost-minimization analysis comparing QW and TIW EPO dosing from a societal perspective. METHODS: Direct and indirect medical cost data were calculated for a 16-week period for 2 large, prospective, multicenter, community-based studies. Costs measured included EPO, transfusions, laboratory tests, office visits, and opportunity cost of patient time. RESULTS: The average total costs in 2002 (first half) dollars were nearly equivalent across the 2 groups (QW: 9,204 dollars; 95% confidence interval [CI], 9,057 dollars-9,350 dollars. TIW: 9,265 dollars; 95% CI, 9,083 dollars-9,447 dollars. P=0.60). QW incurred mean drug acquisition costs that were 23% higher (QW: 6,725 dollars; 95% CI, 6,611 dollars-6,838 dollars. TIW: 5,474 dollars; 95% CI, 5,350 dollars-5,598 dollars. P<0.001). However, QW patients can avoid the resource use and time cost associated with 2 additional office visits incurred each week (QW: 592 dollars [583 dollars-600 dollars]; TIW: 1,709 dollars [1,678 dollars-1,740 dollars]; P<0.001). Transfusion and laboratory test costs were slightly higher in the TIW group (QW: 1,888 dollars [1,837 dollars-1,940 dollars]; TIW: 2,082 dollars [2,020 dollars-2,144 dollars]; P<0.001). CONCLUSION: Total anemia treatment costs over a 16-week period with EPO QW were similar to those of TIW dosing. In the absence of cost differences between regimens, the noneconomic advantages of less-frequent dosing intervals should make weekly dosing increasingly attractive to patients, clinicians, and payers.     

Darbepoetin alfa. Amgen

Amgen has launched darbepoetin alfa, synthetic recombinant novel erythropoiesis stimulating protein (NESP), for the treatment of anemia associated with renal disease. The drug was approved by the European Commission in June 2001, under the tradename Aranesp, for the treatment of anemia in chronic kidney failure including patients on and not yet on dialysis. The company launched the drug on day one of its approval in the following countries: Germany, Sweden, Denmark, Portugal, the Netherlands, the UK and Austria. Roll out of the drug in Italy, Greece and France will follow as soon as pricing and reimbursement issues are resolved [412240], [412357]. By January 2001, the product was still under review and the company anticipated approval during the first half of 2001 in both the US and Europe [396802]. Launch in the US had originally been scheduled for 2000 [387293], [396802] and Japanese launch is planned for 2004 or 2005 [405915]. In January 2001, Amgen reported that the first pivotal trial of darbepoetin alfa in treating oncology patients with anemia was successful [396526], [396802]. The company anticipated a phase III trial in US patients in 2001 for the oncology indication 13977941. In the fourth quarter of 2000, darbepoetin alfa entered phase I trials in Japan. Japanese development of darbepoetin alfa was being conducted by Kirin Brewery (under the research code KRN-321) [396653]. In January 2001, Genesis Pharma licensed the rights to distribute, market and sell darbepoetin alfa for the treatment of anemia, in Greece and Cyprus [396437]. MegaPharm Ltd signed an agreement with Amgen in February 2001, granting MegaPharm certain exclusive rights to distribute, market and sell darbepoetin alfa in Israel [398897]. In February 2000, Merrill Lynch predicted that darbepoetin alfa sales will be in excess of $1.4 billion at maturity [355817]. In October 2000, darbepoetin alfa annual sales were predicted to hit $3 billion [387293].     

重组人红细胞生成素每周方案治疗化疗相关性贫血23例疗效观察

目的观察重组人红细胞生成素（rhEPO）每周方案治疗化疗相关性贫血的疗效和安全性。方法将43例肿瘤化疗相关性贫血患者分为治疗组和对照组。治疗组予rhEPO治疗,40000U皮下注射,1次/周,疗程8周;对照组未用rhEPO治疗,其他如补铁、支持治疗等两组均相同。观察治疗期间Hb、HCT、RBC的变化及不良反应情况,比较两组Hb反应率、输血率差异。结果治疗组Hb水平显著提高;8周后治疗组与对照组Hb反应率分别为69.5%和20.0%,输血率分别为8.7%和30.0%,差异有统计学意义（均P〈0.05）。且治疗组无严重不良反应发生。结论 rhEPO每周方案治疗肿瘤化疗相关性贫血能够有效提高Hb水平、减少输血需求,而且使用安全、耐受性好。     

A study of the response of elderly patients with end-stage renal disease to epoetin alfa or beta

BACKGROUND: Anaemia correction in patients with end-stage renal disease has been enhanced following the use of epoetin alfa or beta and there are a number of studies detailing its application. Dialysis centres are dealing with greater numbers of elderly patients and anaemia correction in these individuals may differ by virtue of co-existing comorbidity and their age. OBJECTIVE: The aim of this study was to examine the response of the elderly patients to anaemia correction using a locally devised anaemia correction protocol while receiving dialysis. METHODS: An incident, non-randomised, cohort observational study in a single centre was used to compare the correction of anaemia in a population of elderly (> or =65 years of age) and young dialysis patients. All incident patients starting peritoneal dialysis and haemodialysis (HD) between January 1998 and December 2000 were selected and treated using a locally devised anaemia correction protocol and observed for at least 1 year. Anaemia correction following adjustments for factors such as age, comorbidity, dialysis type, dialysis access type and predialysis nephrological care was assessed. RESULTS: 198 patients commenced dialysis with 86 elderly patients (mean age +/- SD 73.7 +/- 4.9 years). The elderly patients had similar periods of predialysis nephrological care as the younger patients. Most patients received HD and required a tunnelled dialysis catheter (TC) as vascular access. Equivalent numbers of elderly patients received peritoneal dialysis. Comorbid scores were greater in the elderly and patient survival was dependent upon these comorbid factors. Following the strict use of TCs, patient survival was similar to those patients commencing HD with arterio-venous fistulae.Anaemia correction in the elderly was similar to the younger patients, with a median haemoglobin of 11.3 g/dL. By 6 months of dialysis, most patients achieved the UK Renal Association anaemia correction standard (haemoglobin above 10 g/dL). The elderly patients maintained significantly higher serum ferritin levels throughout (median 209 microg/L) and required less epoetin alfa or beta (median 91.6 units/kg/wk), indicating that functional iron deficiency in the elderly dialysis patients is less. Intravenous iron sucrose doses were similar in both age groups and iron overload (serum ferritin above 800 microg/L) had been avoided following the use of the intravenous iron protocol. CONCLUSION: The study has noted that elderly patients responded to anaemia corrective therapies as well as the younger patients, despite greater levels of comorbidity while requiring less epoetin alfa or beta.     

Epoetin Beta: a review of its clinical use in the treatment of anaemia in patients with cancer

Epoetin beta (NeoRecormon) is a recombinant form of erythropoietin. It increases reticulocyte counts, haemoglobin (Hb) levels and haematocrit. Epoetin beta administered subcutaneously once weekly corrected anaemia and had equivalent efficacy to that of epoetin beta administered three times weekly in patients with haematological malignancies. Subcutaneous epoetin beta reduced transfusion requirements and increased Hb levels versus no treatment in patients with solid tumours and chemotherapy-induced anaemia in nonblind, randomised trials. Anaemia and quality of life were also improved, and blood transfusion requirements were reduced to a significantly greater extent than placebo or no treatment (with supportive blood transfusion) in patients with haematological malignancies. Most patients were receiving chemotherapy. Subcutaneous epoetin beta was well tolerated by patients with cancer; adverse events with the drug occurred with a similar incidence to those with placebo or no treatment (with supportive blood transfusion). Hypertension was relatively uncommon with epoetin beta in clinical trials. Patients with haematological malignancies and a baseline platelet count > or =100 x 10(9)/L, Hb levels of > or =9 g/dL or lower erythropoietin levels have demonstrated better responses to epoetin beta than other patients in clinical trials. However, neither baseline erythropoietin level nor the observed to predicted ratio of erythropoietin levels correlated with the response to epoetin beta in patients with solid tumours and chemotherapy-induced anaemia. A decrease of <1 g/dL or an increase in Hb with epoetin beta during the first chemotherapy cycle indicated a low transfusion need in subsequent cycles in patients with ovarian carcinoma. In general, the efficacy of epoetin beta is not limited by tumour type. Response to the drug occurred irrespective of the nature (platinum- or nonplatinum-based) or presence of chemotherapy treatment in randomised trials. CONCLUSION: Epoetin beta has shown efficacy in the management of cancer-related anaemia in patients with haematological malignancies and of chemotherapy-induced anaemia in patients with solid tumours. Once-weekly administration provides added convenience for patients and may be cost saving, although additional research into the potential pharmacoeconomic benefits of this regimen are required. The drug is well tolerated in patients with cancer and is associated with little injection-site pain when administered subcutaneously. Epoetin beta is an important option in the prevention of chemotherapy-induced anaemia, and a valid and valuable alternative to blood transfusion therapy for the treatment of cancer-related or chemotherapy-induced anaemia.     

Comparison of the therapeutic effects of epoetin zeta to epoetin alfa in the maintenance phase of renal anaemia treatment

ABSTRACT

Objective: To evaluate the therapeutic efficacy and safety of epoetin zeta, compared with epoetin alfa, in maintaining target haemoglobin (Hb) concentrations in patients with anaemia and chronic kidney disease (CKD) maintained on haemodialysis.

Methods: Patients received epoetin zeta or epoetin alfa intravenously, 1–3 times/week for 12 weeks, then the alternative treatment for 12 weeks, in this double-blind, crossover, phase III trial. Eligible patients were 18–75 years old with CKD stage 5 maintained on haemodialysis. Patients had received epoetin for ≥ 3 months upon study entry and had achieved a target Hb level of 10.5–12.5?g/dL with a stable epoetin dose.

Main outcome measures: Primary efficacy endpoints were intra-individual differences (test–reference) in mean Hb levels and mean weekly dose/kg of body weight. Safety endpoints included occurrence of neutralizing anti-erythro­poietin antibodies, tolerability, and adverse events (AEs).

Results: In total, 313 patients were randomized to receive epoetin zeta (n = 155) or epoetin alfa (n = 158); 146 and 145 patients (respectively) switched treatment after 12 weeks. Mean (range) Hb levels were 11.35 (8.96–14.22) g/dL and 11.54 (8.74–13.84) g/dL for patients receiving epoetin zeta and epoetin alfa, respectively (95% confidence interval [CI] [test–reference]: 0.09–0.28?g/dL, within the predefined equivalence range of ±?0.6?g/dL). Mean (range) weekly doses were 92.68 (12.74–398.41) IU/kg/wk and 92.58 (10.53–393.07) IU/kg/wk for patients receiving epoetin zeta and epoetin alfa, respectively (95% CI [test–reference]: –4.67 and 4.29 IU/kg/wk, within the equivalence range of ±?45.00?IU/kg/wk). Patients underwent minor nominal dose adjustments during treatment crossover. AE profile was similar for both products; the most commonly reported AEs were infections and infestations (in 26.5% of patients receiving epoetin zeta and 23.6% receiving epoetin alfa). No patients developed neutralizing anti-erythropoietin antibodies.

Conclusions: Epoetin zeta is therapeutically equivalent to epoetin alfa in the maintenance of target Hb levels in patients with renal anaemia. No unexpected AEs were seen.     

Dosing patterns and treatment costs of erythropoietic agents in elderly patients with pre-dialysis chronic kidney disease in managed care organisations

OBJECTIVES: To investigate dosing patterns and drug costs of erythropoietic agents and assess the frequency of outpatient nephrologist visits in an elderly population with pre-dialysis chronic kidney disease (pCKD) newly initiated on epoetin alfa (EPO) or darbepoetin alfa (DARB). METHODS: An analysis of medical claims from more than 30 healthcare plans covering all census regions of the US in the period July 2002 through February 2005 was conducted. Patients were included if they were > or = 65 years of age, had at least one claim for CKD within 90 days prior to the initiation of any erythropoietic agent, were newly commenced on either EPO or DARB, and had received at least two treatment doses. If a patient received renal dialysis, data were censored 30 days prior to the first date of dialysis. Patients diagnosed with cancer or those who had undergone chemotherapy were excluded from the analysis. The average dosing interval for both EPO and DARB was calculated and classified as once weekly (qw), every 2 weeks (q2w) or every 3 weeks or less frequently (> or = q3w). Weighted average weekly doses were scaled based on treatment duration. The frequency of outpatient nephrologist visits was analysed. Average weekly treatment costs were calculated and presented using the May 2005 Wholesale Acquisition Costs. RESULTS: A total of 293 EPO and 102 DARB patients met the inclusion criteria. The two groups of patients had similar mean age (74.4 years for EPO vs 74.3 years for DARB) and gender distribution (47.4% female for EPO vs 51.0% for DARB). Extended dosing (every 2 weeks or less frequently: > or = q2w) during treatment was observed in both groups (EPO: qw 49.8%, q2w 31.7%, > or = q3w 18.4%; DARB: qw 19.6%, q2w 52.9%, > or = q3w 27.5%). The average dosing interval between injections was 13.6 days for the EPO group and 17.3 days for the DARB group. The weighted average weekly dose was 12,748 units for EPO and 43.5 microg for DARB. The average weekly erythropoietic treatment cost was significantly greater for DARB compared with EPO (190 US dollars vs 155 US dollars per week [2005 values]; p = 0.028). After controlling for covariates, the cost difference between the two groups was more pronounced and remained statistically significant (adjusted cost difference 41 US dollars/week higher for DARB patients; p = 0.013). The frequency of outpatient nephrologist visits during treatment was similar between the two groups (EPO 3.4 vs DARB 3.0 visits). CONCLUSIONS: Based on this analysis of claims data from more than 30 US healthcare plans, extended dosing (> or = q2w) of EPO and DARB was common in elderly pCKD patients treated with erythropoietic agents, with significantly higher weekly drug costs observed in the DARB group compared with the EPO group. The number of outpatient nephrologist visits was not significantly different between EPO and DARB patients. This study was the first to evaluate the dosing patterns of EPO and DARB in elderly pCKD patients in a large managed care population.