Darbepoetin alfa: in patients with chemotherapy-related anaemia

Darbepoetin alfa, novel erythropoiesis stimulating protein closely related to human erythropoietin, has been developed for the treatment of chemotherapy-related anaemia in patients with non-myeloid malignancies. In three 12-week, phase II studies in patients with cancer and chemotherapy-related anaemia, subcutaneous darbepoetin alfa, administered in once-weekly or 2-, 3- or 4-weekly regimens, dose-dependently increased the mean haemoglobin levels. In a randomised, double-blind, phase III study in 320 patients with lung cancer and chemotherapy-related anaemia, recipients of subcutaneous darbepoetin alfa 2.25 micro g/kg once weekly, received red blood cell (RBC) transfusion approximate, equals 2-fold less frequently than placebo recipients (p < 0.001). In the same study, patients receiving darbepoetin alfa also received fewer standard units of RBC for transfusion and had greater haematopoietic response rate than placebo recipients (both p < 0.001). Subcutaneous darbepoetin alfa 2.25 micro g/kg once weekly also reduced patient-reported fatigue (assessed by a quality-of-life questionnaire) [p = 0.019 vs placebo]. black triangle Darbepoetin alfa was generally well tolerated in clinical trials. The most frequent darbepoetin alfa-related adverse events were: body oedema, arthralgia and skin rash.     

Epoetin alfa and epoetin beta: new indication. Treatment of anaemia due to cytotoxic chemotherapy

(1) The standard treatment for symptomatic anaemia due to cytotoxic chemotherapy is blood transfusion. (2) The licensing terms for epoetin alfa have been extended to cover the treatment of anaemia induced by all cytotoxic drugs, no longer only by platinum salts. The licensing terms for epoetin beta have been extended to cover some haematological malignancies. (3) The clinical file on epoetin alfa contains data from 8 placebo-controlled double-blind trials in patients with anaemia. Four trials showed a significant reduction (of 12-35%) in the number of patients transfused during the second and third months of treatment with epoetin alfa. (4) Quality of life was mentioned in only two trial reports. In one, the score was significantly better on epoetin alfa than on placebo, but the practical repercussions of this difference are unclear. In the other trial there was no significant difference between the groups. (5) The clinical file on epoetin beta contains data only from unblended dose-finding studies showing a favourable impact on the haemoglobin level and transfusion requirements. (6) The preventive effect of the two epoetins has not been compared with that of alternative treatments. (7) The main known risks of epoetin are arterial hypertension and thrombosis. Stimulation of tumour growth cannot be ruled out. (8) Epoetin beta has a practical advantage, in that it can be stored for a few days at room temperature. (9) In practice, epoetin is the standard treatment of anaemia after chemotherapy, outside emergency situations.     

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.     

The use of darbepoetin alfa for the treatment of chemotherapy-induced anaemia

Chemotherapy-induced anaemia, with its important consequences on quality of life and social function of cancer patients, can be improved with erythropoietic therapy. Darbepoetin alfa is the first of a novel generation of erythropoietic proteins with a unique molecular structure and a circulating half-life that is threefold longer than that of the previous recombinant human erythropoietin. The efficacy and safety of weekly administration have been confirmed in different Phase II and III randomised trials. In order to optimise the efficacy profile of darbepoetin alfa, extended dosing intervals and front-loading regimens are evaluated, as well the optimal haemoglobin level to initiate therapy. Across all trials, darbepoetin alfa was shown to be a well-tolerated and safe therapy. The possible favourable effect on the outcome of cancer patients needs to be further elucidated.     

Epoetin alfa (Eprex) and quality of life

Several recently published clinical trials in anaemic patients with cancer provide convincing evidence that the quality of life of such patients is considerably impaired and that a significant improvement in quality of life can be achieved if their anaemia is corrected by treatment with recombinant erythropoietin (epoetin alfa, Eprex). Findings of some of the major studies are summarised in this issue. These summaries have been prepared to make the findings more accessible to busy clinicians who may not have time to read longer reports in specialist journals but who need to understand the important clinical implications of this research.     

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.     

Epoetin alfa for the treatment of combination therapy-induced hemolytic anemia in patients infected with hepatitis C virus

In the United States, about 2.7 million people are chronically infected with the hepatitis C virus, accounting for nearly 1.8% of the population. The current standard of therapy is a combination of pegylated interferon products and ribavirin. A common adverse effect associated with this therapy is anemia, which is frequently referred to as mixed anemia because of the synergistic contribution of the interferons and ribavirin. The effect of ribavirin on the development of anemia is considered greater than that of interferon. The current standard of practice for treating this adverse effect is reduction of the dosages of both drugs, at prespecified hemoglobin levels. However, recent findings underscore the importance of maintaining adequate dosages of interferon and ribavirin, which may be crucial in achieving an early virologic response and a sustained virologic response in treating patients with hepatitis C infection. Treatment with epoetin alfa for this mixed anemia significantly improved hemoglobin levels and quality of life, and enabled adequate dosages of ribavirin to be maintained. Future studies should address several issues: when to start epoetin alfa treatment, the duration of treatment, the drug's optimal dosage, its effects on end-of-treatment and sustained virologic response rates, and a cost analyses.     

Epoetin alfa protocol and multidisciplinary blood-conservation program for critically ill patients.

PURPOSE: An evidence-based epoetin alfa protocol and a multidisciplinary blood-conservation program were implemented in a medical intensive care unit (MICU) and surgical intensive care unit (SICU). SUMMARY: Baseline data were collected to evaluate the use of epoetin alfa and red blood cell (RBC) transfusions in our MICU and SICU. An evidence-based protocol for epoetin alfa use and a multidisciplinary blood-conservation program were designed, approved, and implemented. Preprotocol patients consisted of a convenience sample of 18 patients receiving epoetin alfa for various indications who were admitted to our MICU and SICU from January 1 to December 31, 2002. The postprotocol sample consisted of 40 patients who received epoetin alfa for the treatment of anemia due to critical illness who were admitted to the MICU and SICU from March 25 to May 23, 2003. Postprotocol data were collected and compared with baseline data. All patients seen in the MICU and SICU, during the postprotocol period, regardless of whether they were receiving epoetin alfa, were included in the multidisciplinary blood-conservation program. Postprotocol data showed statistically significant improvements in epoetin alfa dosing and monitoring and in the use of adjunctive therapy. Pharmacist-initiated blood-conservation strategies resulted in several blood-draw reductions and discontinuations. Statistically significant reductions in the number of RBC units transfused per patient and per intensive care unit (ICU) day were also observed. CONCLUSION: An epoetin alfa protocol and a multidisciplinary blood-conservation program contributed to rational prescribing of epoetin alfa and to a reduction in the number of RBC units transfused per patient and per ICU day.     

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.     

Naltrexone for the treatment of obesity: review and update

Since their discovery in the brain and gastrointestinal tract nearly 40 years ago, endogenous opioid peptides have been progressively shown to play a role in the regulation of food intake. Animal and human studies regarding opioid peptides and ingestive behavior are reviewed. While the opioid receptor antagonist naltrexone is associated with minimal weight loss as monotherapy, it does have potential utility in the treatment of obesity when combined with the pro-opiomelanocortin activator bupropion.     

Epoetin delta is effective for the management of anaemia associated with chronic kidney disease

ABSTRACT

Objective: To demonstrate the efficacy and safety of epoetin delta for the treatment of anaemia in dialysis patients with chronic kidney disease (CKD).

Research design and methods: This was a 12‐week, randomized, double-blind, active-comparator study. CKD patients who were naïve to epoetin treatment and had haemoglobin < 10?g/dL were randomized to epoetin delta 15, 50, 150, or 300 IU/kg or epoetin alfa 50 IU/kg. Patients initially entered a correction phase until they recorded haemoglobin of ≥ 11.5?g/dL for two consecutive weekly measurements or one haemoglobin measurement of ≥ 13?g/dL (correction success). A maintenance phase followed where the dose was adjusted to maintain haemoglobin ≥ 10.5?g/dL. Maintenance success was defined as haemoglobin > 10.5?g/dL at Week 12. Total success was defined as achieving maintenance and correction success.

Main outcome measures: The primary objective was to demonstrate that the proportion of patients achieving total success was greater in the pooled 150?IU/kg and 300?IU/kg groups compared with the 15?IU/kg dose group.

Results: Total success was achieved in 55.6% of patients in the pooled highest epoetin delta group compared with 4.5% in the lowest dose group. There was no significant difference in total success for the epoetin delta and epoetin alfa 50?IU/kg groups. Significant increases in haemoglobin and haematocrit levels were observed in the 150 and 300?IU/kg dose groups. Adverse events occurred at frequencies expected for this patient group.

Conclusions: Epoetin delta was effective in increasing haemoglobin levels in patients with baseline haemoglobin of < 10?g/dL.     

Epoetin alfa offers clinically significant improvements in the quality of life of anaemic cancer patients

Anaemia is a common problem for cancer patients and often causes fatigue and reduces quality of life (QoL). Although randomised trials have repeatedly shown that treatment with epoetin alfa raises haemoglobin levels, reduces fatigue and improves overall QoL, such findings may be hard to put into a clinical context and, as a result, cancer-related fatigue remains undertreated. This study gathered data using the FACT-An QoL scale from 1400 people on an internet survey panel. The 1400 were randomly selected and chosen to be representative of the total US population. Survey results were then compared with the findings from a large placebo-controlled study involving 375 anaemic cancer patients. FACT-An showed good psychometric properties in the survey population and was able to distinguish respondents with histories of anaemia and cancer from those without. Comparing the population norm values for FACT-An with the trial data showed that treatment with epoetin alfa led to clinically meaningful improvements in cancer patients' QoL.     

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.     

Biophysical comparability of the same protein from different manufacturers: a case study using Epoetin alfa from Epogen and Eprex

This study focuses on the development and application of biophysical methodology to characterize conformations of Epogen and Eprex, the injectable formulations of recombinant human Epoetin alfa produced by different manufacturers and commonly used for the treatment of renal anemia. In these studies Eprex, from prefilled syringes, and Epogen bulk product formulated in a buffer similar to the Eprex formulation, were purified by anion-exchange chromatography. Analytical ultracentrifugation studies of the purified main peak from each sample demonstrated that Epogen contains a single component with an s value of 2.51 while Eprex contains a single component with the same molecular weight but with an s value of 2.44 suggesting a slight difference in hydrodynamic structure. The degree of alpha-helicity was compared by far-UV circular dichroism and shown to contain slight differences. Intrinsic tryptophan fluorescence and near-UV circular dichroism were assessed and demonstrated additional differences between the proteins. Finally, the global stability of the proteins was monitored using thermal unfolding monitored by far-UV circular dichroism. The Epoetin alfa of Epogen demonstrated complete reversibility while the Epoetin alfa purified from Eprex demonstrated only 80%-85% thermal reversibility when heated to 100 degrees C. Together the data indicate that the proteins are not structurally identical.     

Epoetin (recombinant human erythropoietin). A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in anaemia and the stimulation of erythropoiesis

Epoetin (recombinant human erythropoietin) is a sialoglycoprotein hormone that appears to be immunologically and biologically equivalent to the endogenous compound, enhancing erythropoiesis dose-proportionally. The therapeutic efficacy of epoetin in the treatment of anaemia associated with chronic renal failure has been established, with almost all patients responding with increases in haematocrit and haemoglobin levels, and improvements in quality of life. Some patients demonstrate relative epoetin resistance and require a higher dosage to achieve target haemoglobin and haematocrit levels. Maintenance of an adequate iron supply is essential and iron supplementation is recommended if serum ferritin is below 100 to 150 micrograms/L or transferrin saturation is less than 20%. The incidence of serious adverse effects may be reduced by maintaining a moderate rate of increase in the haematocrit with close monitoring of blood pressure and dialysis efficacy. Individual titration of epoetin dosage is recommended, with increases made in small increments to achieve haematocrit and haemoglobin levels of 30 to 33% and 10 to 12 g/dl, respectively, although the optimal haematocrit for each patient should be individually determined. Some patients will also require a modest increase in heparin dosage because of a possible increase in clotting tendency. Hypertension is the most common adverse effect in patients with chronic renal failure, occurring partially as a result of increasing blood viscosity and peripheral vascular resistance with the correction of anaemia. Maintenance epoetin therapy has been given for more than 2 years without a decrease in responsiveness and does not appear to adversely affect the outcome of renal transplantation. Thus, epoetin represents a significant therapeutic advance in the treatment of anaemia associated with chronic renal failure and should be considered a first option for these patients. Its potential value in the treatment of anaemia associated with other disorders and in facilitating autologous blood donation remains to be fully determined.     

A prospective observational study of the effectiveness,safety, and effect on fatigue of darbepoetin alfa for the treatment of chemotherapy-induced anaemia

ABSTRACT

Objective: Anaemia is common in cancer patients treated with chemotherapy. Darbepoetin alfa (DA) is the only erythropoiesis-stimulating protein approved for administration at weekly and every-three-week intervals in cancer patients receiving chemotherapy. This article investigates the effectiveness, tolerability and effect on fatigue of DA.

Methods: Prospective, observational study performed in 30 Spanish centres. Eligible patients were ≥?18?years of age, anaemic (haemoglobin [Hb] ≤?11?g/dL), with non-myeloid malignancies, receiving chemotherapy. DA (150?μg) was administered weekly for a maximum of 16?weeks (dosage doubled if Hb increased <?1?g/dL after 4?weeks).

Main outcome measures: Haematopoietic response (Hb increase ≥?2?g/dL or Hb ≥?12?g/dL in the absence of transfusions in the previous 28?days), transfusion required between Weeks 5 and 16 and fatigue measured by the Fatigue subscale of the Functional Assessment of Cancer Therapy.

Results: 293 adults were recruited (56.4% women), with lymphoproliferative malignancies (44.3%) or solid tumours (55.7%). Baseline Hb was 9–11?g/dL in 83.7% of patients. Sixty-four per cent (95% CI: 58.1–69.4%) had a haematopoietic response and 12% required transfusions. After adjusting for performance status, concomitant diseases and chemotherapy type, an increase in Hb level was significantly associated with an improvement in Fatigue subscale (+1.9 points per 1?g/dL). Only 2% of patients had treatment-related adverse events: thromboembolic pulmonary disease (0.3%); hypersensitivity reaction (0.3%); local pain following DA administration (0.3%); insomnia (0.3%); thrombocytosis (0.3%) and deep vein thrombosis (0.3%).

Conclusions: Fixed-dose DA administered once weekly seems to be an effective, well-tolerated treatment for chemotherapy-induced anaemia in patients with non-myeloid malignancies, and there is an indication of a possible benefit on fatigue in the clinical practice.     

Pharmacological treatment of binge eating disorder: update review and synthesis

Introduction: Binge eating disorder (BED), a formal eating disorder diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), is characterized by recurrent binge eating, marked distress about binge eating, and the absence of extreme weight compensatory behaviors. BED is more prevalent than other eating disorders, with broader distribution across age, sex and ethnic/racial groups, and is associated strongly with obesity and heightened risk for psychiatric/medical comorbidities.

Areas covered: This article provides an overview of pharmacotherapy for BED with a focus on Phase III randomized controlled trials (RCTs). The search with minimal methodological inclusion requirements yielded 22 RCTs investigating several different medication classes; most were pharmacotherapy-only trials with 8 trials testing combination approaches with psychological–behavioral methods.

Expert opinion: The evidence base regarding pharmacotherapy for BED remains limited, although this year the FDA approved the first medication (i.e., lisdexamfetamine dimesylate; LDX) specifically for moderate-to-severe BED. Data from RCTs suggest certain medications are superior to placebos for reducing binge eating over the short term; almost no data exist regarding longer-term effects of pharmacotherapy for BED. Except for topiramate, which significantly reduces both binge eating and weight, tested medications yield minimal weight loss and LDX is not indicated for weight loss. Psychological–behavioral and combination approaches with certain medications yield superior outcomes to pharmacotherapy-only acutely and over longer-term follow-up.