Treatment of anemia with darbepoetin alfa administered de novo once every other week in chronic kidney disease

BACKGROUND/AIMS: Darbepoetin alfa is an erythropoiesis-stimulating protein that works via the same mechanism and has a threefold longer serum half-life than recombinant human erythropoietin (rHuEPO). The objective of this study was to evaluate extending the dosing interval of darbepoetin alfa to once every other week administration for the treatment of anemia in patients with chronic kidney disease (CKD) not requiring dialysis who were naive to rHuEPO therapy. METHODS: This was a multi-center, open-label study. Seventy-six rHuEPO-naive patients were enrolled to receive darbepoetin alfa (0.75 microg/kg) once every other week for up to 24 weeks. Doses were titrated to achieve and maintain a hemoglobin target of 11.0 to 13.0 g/dl. RESULTS: Ninety-seven percent (95% CI: 0.92, 1.00) of patients completing 24 weeks of treatment achieved a hemoglobin response. The median time to response was 5 weeks (range 1-25 weeks). The median darbepoetin alfa dose at the time of response was 60 microg(range 30-130 microg). Darbepoetin alfa was safe and well tolerated, and no antibodies to darbepoetin alfa were detected. CONCLUSION: These results demonstrate the utility of darbepoetin alfa administered once every other week in rHuEPO-naive CKD patients. This new treatment paradigm may allow for more widespread management of anemia in patients with CKD.     

Darbepoetin alfa administered once monthly maintains hemoglobin concentrations in patients with chronic kidney disease

BACKGROUND: Darbepoetin alfa is an erythropoiesis-stimulating glycoprotein that functions by the same mechanism as recombinant human erythropoietin (rHuEPO), but has a three-fold longer serum half-life. Reduction in the frequency of darbepoetin alfa administration would be beneficial to patients with renal disease and their healthcare providers. This study evaluated the effect of extending the darbepoetin alfa dosing interval to once monthly in patients with chronic kidney disease (CKD) not receiving dialysis. METHODS: This study was a multicenter, open-label study of 97 patients with CKD not on dialysis. Patients receiving stable subcutaneous doses of darbepoetin alfa once every two weeks were converted to darbepoetin alfa once monthly for 29 weeks. The proportion of patients who successfully maintained hemoglobin concentrations between 10.0 and 12.0 g/dl and the mean darbepoetin alfa dose were evaluated. Safety measurements (e.g. adverse events, laboratory parameters, blood pressure) and seroreactivity were assessed. RESULTS: Hemoglobin concentration was maintained within the target range in 79% (95% confidence interval (CI) = 71% to 87%) of all patients receiving darbepoetin alfa and in 85% (95% Cl = 78% - 93%) of patients who completed the study period. The mean +/- standard deviation monthly darbepoetin alfa dose was similar between baseline (88.7 +/- 49.9 microg) and the evaluation period (86.6 +/- 78.8 microg). The safety profile for monthly darbepoetin alfa administration was comparable with that previously observed with more-frequent administration. CONCLUSION: Patients with CKD who are clinically stable on darbepoetin alfa administered once every two weeks can be safely and effectively converted to darbepoetin alfa administered once monthly.     

Darbepoetin alfa administered every other week maintains hemoglobin levels over 52 weeks in patients with chronic kidney disease converting from once-weekly recombinant human erythropoietin: results from simplify the treatment of anemia with Aranesp (STAAR)

BACKGROUND/AIM: Darbepoetin alfa, an effective treatment for anemia of chronic kidney disease (CKD), can be administered at extended intervals. Simplify the Treatment of Anemia with Aranesp (STAAR), a multicenter, 52-week study, was conducted to assess the efficacy of darbepoetin alfa administered subcutaneously every other week (Q2W) in maintaining hemoglobin (Hb) in CKD patients not receiving dialysis. METHODS: This is a subgroup analysis of subjects converted from once-weekly (QW) recombinant human erythropoietin (rHuEPO; US Aranesp package insert) and who received up to 52 weeks of darbepoetin alfa therapy (evaluation period 20-32 weeks). Enrolled subjects had a creatinine clearance < or = 70 ml/min or an estimated glomerular filtration rate < or = 60 ml/min and transferrin saturation > or = 20%. Darbepoetin alfa doses were titrated to maintain Hb levels < or = 12 g/dl. The primary endpoint was mean Hb during evaluation. RESULTS: There were 524 subjects enrolled in the study who were previously receiving rHuEPO QW. Mean Hb +/- standard deviation was 11.2 +/- 1.27 g/dl at baseline, and the least squares mean +/- SE was 11.4 +/- 0.04 during evaluation. The mean +/- SD Q2W darbepoetin alfa dose was 49.7 +/- 21.9 microg at baseline and 48.9 +/- 35.5 microg at evaluation. Darbepoetin alfa was well tolerated. CONCLUSIONS: Study subjects with CKD receiving QW rHuEPO were effectively converted to Q2W darbepoetin alfa, which was well tolerated. Hb levels were maintained over 52 weeks without a significant change in darbepoetin alfa dose.     

Treatment of anaemia in dialysis patients with unit dosing of darbepoetin alfa at a reduced dose frequency relative to recombinant human erythropoietin (rHuEpo).

BACKGROUND: Darbepoetin alfa is an erythropoietic agent with a 3-fold longer elimination half-life than recombinant human erythropoietin (rHuEpo), which allows less frequent dosing. This study investigated the safety and efficacy of darbepoetin alfa for treating anaemia in dialysis patients, using a dosing regimen that was independent of the patient's body weight (unit dosing). METHODS: Dialysis patients (n=341) maintained on rHuEpo treatment (alfa or beta) were switched to darbepoetin alfa at a reduced dosing frequency, but by the same route of administration [intravenous (i.v.) or subcutaneous (s.c.)]. Patients receiving rHuEpo two or three times weekly changed to once-weekly darbepoetin alfa, and those receiving rHuEpo once weekly changed to once every other week darbepoetin alfa. The unit doses of darbepoetin alfa (10-150 microg) were titrated to maintain haemoglobin concentrations within -1.0 and +1.5 g/dl of the individual mean baseline haemoglobin and between 10 and 13 g/dl for 24 weeks. RESULTS: Mean change in haemoglobin from baseline to the evaluation period (weeks 21-24) was 0.13 g/dl (95% CI, 0.01, 0.25), which was not clinically relevant. An analysis by route of administration revealed that mean haemoglobin concentrations had increased by 0.58 g/dl (95% CI, 0.33, 0.82) in patients receiving i.v. darbepoetin alfa, and previously treated with i.v. rHuEpo, while remaining unchanged in s.c. patients (0.00 g/dl; 95% CI, -0.13, 0.13) previously treated by s.c. rHuEpo. In addition, there was a statistically significant decrease in mean weekly i.v. darbepoetin alfa dose requirements from 25.2 microg/week at baseline to 21.5 microg/week (P=0.004) during the evaluation period (-17.3%). Subcutaneous weekly dosage requirements increased slightly during the study period (20.8 to 22.7 microg/week; P=0.014). An i.v./s.c. dose ratio of 0.95 (95% CI, 0.78, 1.14) at evaluation confirms previous findings that dose requirements by the i.v. and s.c. routes were not different in patients treated with darbepoetin alfa. Haemoglobin concentrations were also effectively maintained in patients who received darbepoetin alfa once weekly and once every other week. Darbepoetin alfa was well tolerated. CONCLUSIONS: The treatment of renal anaemia in dialysis patients with unit doses of darbepoetin alfa effectively and safely maintains target haemoglobin concentrations with less frequent dosing. Dose requirements for darbepoetin alfa following i.v. and s.c. administration were not different. The results of this study demonstrate that darbepoetin alfa administered i.v. once weekly, or once every other week is an effective treatment regimen for haemodialysis patients with renal anaemia.     

Correction of anaemia with darbepoetin alfa in patients with chronic kidney disease receiving dialysis.

BACKGROUND: Darbepoetin alfa is a new recombinant erythropoietic protein with a 3-fold longer half-life than recombinant human erythropoietin (rHuEpo). The optimal starting dose and frequency of administration of darbepoetin alfa were investigated for treating renal anaemia in dialysis patients. METHODS: Two multicentre, sequential dose-escalation studies examined the i.v. route of administration of darbepoetin alfa in haemodialysis patients (n=75) and the s.c. route in peritoneal dialysis patients (n=47). Patients were randomized to receive darbepoetin alfa at doses ranging from 0.075 to 0.75 microg/kg/week administered as either a once weekly or a three-times weekly injection. Patients achieving the primary endpoint of a > or = 1 g/dl increase in haemoglobin after 4 weeks continued darbepoetin alfa for up to 52 weeks. Safety was assessed by adverse event reports, changes in laboratory values and vital signs, and antibody screening. RESULTS: Darbepoetin alfa produced dose-related increases in haemoglobin over the first 4 weeks of treatment in both studies. Two dose levels (0.45 and 0.75 microg/kg/week) increased the haemoglobin by > or = 1 g/dl in 60-80% of patients, and no difference between once weekly and three-times weekly dosing was apparent. For patients who continued treatment up to 52 weeks, haemoglobin was maintained between 10 and 13 g/dl from mean baseline values of 8.4 and 8.7 g/dl. The adverse event profile was similar to that associated with rHuEpo therapy, and no antibodies to darbepoetin alfa were detected. CONCLUSIONS: Darbepoetin alfa is safe and effective for the treatment of anaemia in dialysis patients. The optimal weekly starting dose is 0.45-0.75 microg/kg and once weekly dosing is possible for both the s.c. and i.v. routes of administration.     

Darbepoetin alfa effectively maintains haemoglobin concentrations at extended dose intervals relative to intravenous or subcutaneous recombinant human erythropoietin in dialysis patients.

BACKGROUND: Darbepoetin alfa is a unique molecule that stimulates erythropoiesis by the same mechanism as endogenous erythropoietin. Due to its approximately 3-fold longer half-life and greater biological activity than recombinant human erythropoietin (rHuEpo), darbepoetin alfa maintains effective haemoglobin control at extended dose intervals compared with rHuEpo. This study assessed the efficacy and safety of unit doses of darbepoetin alfa for the treatment of renal anaemia. METHODS: In this multicentre, prospective, open-label study, 1502 dialysis subjects maintained on stable rHuEpo treatment were switched to darbepoetin alfa at extended dose intervals by the same route of administration as previous rHuEpo therapy [intravenous (i.v.), n = 900 or subcutaneous (s.c.), n = 602]. Subjects receiving rHuEpo two (n = 408, 27%) or three times (n = 884, 59%) a week were switched to darbepoetin alfa once a week, and those receiving rHuEpo once a week (n = 210, 14%) were switched to darbepoetin alfa once every 2 weeks. The unit doses of darbepoetin alfa (10-150 microg) were titrated to maintain haemoglobin concentrations of 10-13 g/dl for 24 weeks. RESULTS: Haemoglobin concentrations were maintained effectively in subjects regardless of whether they received darbepoetin alfa once a week or once every 2 weeks. The overall mean change in haemoglobin from baseline to the evaluation period (weeks 21-24) was +0.10 g/dl [95% confidence interval (CI) 0.04+/- 0.17]. The mean haemoglobin concentration increased by 0.19 g/dl (95% CI 0.11+/-0.27) in subjects receiving i.v. darbepoetin alfa, and was unchanged (-0.02 g/dl; 95% CI -0.12 to 0.07) in patients treated with s.c. darbepoetin alfa. Subjects with baseline haemoglobin < 11 g/dl experienced a clinically relevant increase in mean haemoglobin concentration of 0.67 g/dl (95% CI 0.56+/-0.77) from baseline to the evaluation period. The mean weekly i.v. and s.c. darbepoetin alfa dosage requirements during the evaluation period were 19.9 microg/week (95% CI 19.02+/-20.87) and 21.6 microg/week (95% CI 20.36+/- 22.94), respectively. Darbepoetin alfa was well tolerated and the safety profile was consistent with previous trials with darbepoetin alfa in dialysis subjects. CONCLUSIONS: Treating renal anaemia with darbepoetin alfa administered at extended dose intervals is both effective and well tolerated. Moreover, administration of darbepoetin alfa by both the i.v. and s.c. route is associated with stable haemoglobin concentrations.     

Darbepoetin alfa administered once monthly maintains haemoglobin levels in stable dialysis patients.

BACKGROUND: Darbepoetin alfa, a glycoprotein that stimulates erythropoiesis by the same mechanism as endogenous erythropoietin, has a 3-fold longer terminal half-life than recombinant human erythropoietin, allowing for an extended dosing interval. Darbepoetin alfa is currently recommended for once-weekly and once every 2 weeks administration in patients with chronic renal failure (CRF). The objective of this study was to explore once-monthly administration in this patient population. METHODS: Clinically stable dialysis patients (mean haemoglobin concentration, 10.0-13.0 g/dl) receiving stable darbepoetin alfa therapy administered once every 2 weeks in a long-term treatment study were converted to darbepoetin alfa once every 3 weeks for 20 weeks and then, if haemoglobin concentrations were successfully maintained between 10.0 and 13.0 g/dl, were converted to darbepoetin alfa once every 4 weeks for 20 weeks. The darbepoetin alfa dose was titrated to maintain haemoglobin within a target range (-1.0 to +1.5 g/dl of baseline haemoglobin, and between 10.0 and 13.0 g/dl). Success with the extended dosing interval was defined as maintenance of mean haemoglobin >/=10.0 g/dl during a 4-week evaluation at the end of the dosing period. RESULTS: Of the 54 patients who entered the study, 38 patients were converted to darbepoetin alfa administered once every 4 weeks. Of these, 36 patients were considered evaluable and 30 (83%) of those evaluable patients successfully maintained the target haemoglobin. For successful patients the mean (SD) haemoglobin during evaluation was 11.16 (0.60) g/dl, and the mean change in haemoglobin from baseline to evaluation was -0.26 g/dl (95% CI: -0.51, -0.01). The median change from baseline in average weekly darbepoetin alfa dose was 1.61 microg (95% CI: 0.00, 4.75). Adverse events were consistent with those expected for this patient population. CONCLUSIONS: Darbepoetin alfa, administered once monthly, maintained haemoglobin effectively and safely in most dialysis patients stabilized previously on once every 2 weeks dosing. Once-monthly dosing may optimize anaemia management for patients with CRF and for health care providers.     

The efficacy of intravenous darbepoetin alfa administered once every 2 weeks in chronic kidney disease patients on haemodialysis.

BACKGROUND: It is becoming increasingly more common to administer intravenous (i.v.) darbepoetin alfa to haemodialysis (HD) patients at less frequent dosing intervals in routine clinical practice. This study investigated extending the dosing interval for i.v. darbepoetin alfa treatment from once a week (QW) to once every 2 weeks (Q2W) at the same dose in order to maintain target haemoglobin (Hb) concentrations (11-13 g/dl). METHODS: Stable HD patients in routine clinical practice receiving i.v. darbepoetin alfa QW for a period of 6 months (n = 105) (treatment period 1) were switched to i.v. Q2W darbepoetin alfa for a further 6 months (treatment period 2) (n = 90). The dose of i.v. darbepoetin alfa was titrated to maintain Hb concentrations between 11 and 13 g/dl throughout the full 12-month study period. RESULTS: The mean change in Hb for treatment period 2 was 0.04 +/- 1.1 g/dl (+/-SD), which was not clinically relevant (11.7 +/- 0.8 g/dl vs 11.7 +/- 1.0 g/dl; P = 0.8). The mean weekly doses of darbepoetin alfa were similar throughout the treatment periods (34.0 +/- 17.1 microg/week vs 32.1 +/- 17.3 microg/week; P = 0.3, respectively for QW and Q2W dosing). Intravenous darbepoetin alfa was well tolerated. CONCLUSIONS: The treatment of renal anaemia in HD patients with i.v. Q2W darbepoetin alfa effectively and safely maintains Hb concentrations at a less frequent dosing regimen than observed with QW administration. Dose requirements for i.v. darbepoetin alfa administered QW or Q2W were not different. The results of this study demonstrate that i.v. darbepoetin alfa administered Q2W is an effective regimen for HD patients requiring anaemia treatment in routine clinical practice.     

Randomized trial of darbepoetin alfa for treatment of renal anemia at a reduced dose frequency compared with rHuEPO in dialysis patients

BACKGROUND: Darbepoetin alfa is a glycoprotein with a three-fold longer terminal half-life than recombinant human erythropoietin (rHuEPO). We aimed to determine whether darbepoetin alfa is as effective and well tolerated as rHuEPO for treating renal anemia in dialysis patients when administered at a reduced dose frequency. METHODS: A total of 522 European and Australian hemodialysis and peritoneal dialysis patients receiving stable rHuEPO therapy by either the intravenous (IV) or subcutaneous (SC) route were randomized, open-label in a 1:2 ratio to continue rHuEPO or to receive an equivalent dose of darbepoetin alfa at a reduced dose frequency. Patients receiving rHuEPO once weekly changed to once every other week darbepoetin alfa, and those receiving rHuEPO two or three times weekly changed to once-weekly darbepoetin alfa. The doses of rHuEPO and darbepoetin alfa were titrated to maintain hemoglobin close to the patient's baseline level for up to 52 weeks. The primary endpoint was the change in hemoglobin between baseline and the evaluation period at weeks 25 to 32 of treatment. RESULTS: The mean change in hemoglobin from baseline to the evaluation period was similar in the darbepoetin alfa (-0.03 g/dL; SE 0.11) and rHuEPO (-0.06 g/dL; SE 0.13) groups, and the difference between the two treatments was 0.03 g/dL (95% CI -0.16, 0.21). This was not a statistically significant or clinically relevant difference, despite the reduced frequency of darbepoetin alfa administration. At the end of the evaluation period, >/=95% of patients had their hemoglobin successfully maintained on their assigned dose frequency for darbepoetin alfa (once weekly and once every other week) and rHuEPO (once, twice and three times weekly). The safety profiles of darbepoetin alfa and rHuEPO were similar, and no antibodies to either treatment were detected. CONCLUSIONS: Darbepoetin alfa maintains hemoglobin as effectively as rHuEPO, but with a reduced dose frequency.     

Darbepoetin-alfa treatment of anemia secondary to chronic renal failure in dialysis patients: Results of a French multicenter study

Darbepoetin alfa is a unique genetically engineered glycoprotein with a three-fold longer terminal half-life than recombinant human erythropoietin (rHuEPO). The objective of this study was to determine if darbepoetin alfa administered at a reduced dosing frequency relative to the prior rHuEpo regimen is an effective and safe alternative for treating renal anemia in patients undergoing dialysis. A total of 1,008 French hemodialysis and peritoneal dialysis patients receiving stable rHuEPO therapy by either the intravenous (i.v., N = 217) or subcutaneous (s.c., N = 791) route were switched to darbepoetin alfa given by the same route of administration at a reduced dosing frequency. Patients receiving rHuEPO once weekly (N = 248, 25%) were switched to darbepoetin alfa every two weeks, and those receiving rHuEPO two or three times weekly (N = 760, 75%) were switched to darbepoetin alfa once weekly. The doses of darbepoetin alfa were titrated to maintain hemoglobin concentration in the target range of 10.0 to 13.0 g/dl for up to 24 weeks. The primary endpoint was the change in hemoglobin between baseline and the evaluation period (weeks 21-24). Adjusted (for covariates that might influence hemoglobin response) mean change in hemoglobin from baseline to the evaluation period was not clinically significant: +0.11 g/dl (95% CI: -0.30; 0.52). An i.v./s.c. dose ratio of 0.96 (95% CI: 0.86; 1.06) at evaluation confirms previous findings that darbepoetin alfa dose requirements were not different for the s.c. and i.v. routes. At the end of the evaluation period, more than 98% of patients successfully maintained hemoglobin within the target range and at their darbepoetin alfa assigned dosing frequency. Darbepoetin alfa was well tolerated with a safety profile consistent with that observed in previous darbepoetin alfa studies. Darbepoetin alfa administered at a reduced dosing frequency relative to the prior rHuEpo regimen effectively maintains hemoglobin in the target range in dialysis patients with renal anemia.     

Intravenously administered darbepoetin alfa once a week could maintain hemoglobin level more efficiently than once every 2 weeks in patients on hemodialysis

Background

Darbepoetin alfa, which has a much longer half-life than recombinant human erythropoietin, is used to treat renal anemia. However, there are few reports investigating the efficacy of darbepoetin alfa administered every 2 weeks (Q2W).

Methods

We performed the single-center, prospective, and randomized study in chronic hemodialysis patients. Clinically stable patients on hemodialysis were recruited, and darbepoetin alfa 15–40 μg/week was administered intravenously once a week (QW) to achieve a hemoglobin (Hb) level of 10.5–12.0 g/dl for 8 weeks prior to randomization. The patients were randomly assigned to 2 different dosing frequency groups: once a week (QW) or every 2 weeks (Q2W). We switched to a double dose in the Q2W group. We measured Hb level every 2 weeks and administered darbepoetin alfa to achieve an Hb level of 10.5–11.5 g/dl. The primary endpoints were the weekly dose of darbepoetin alfa administered at week 24.

Results

We assigned 19 and 20 patients into QW and Q2W, respectively. There were no significant differences between the groups in Hb, transferrin saturation, ferritin, and weekly dose of darbepoetin alfa at end of the baseline period. There was no significant difference in Hb level at week 24, at which time the weekly dose requirement and dose per dry body weight were much higher in the Q2W than in the QW group.

Conclusion

Administration of darbepoetin alfa Q2W could maintain Hb level similarly to to that obtained QW, but we did not confirm efficiency at a higher dose requirement or blood pressure elevation.     

Effectiveness of weekly darbepoetin alfa in the treatment of anaemia of HIV-infected haemodialysis patients.

BACKGROUND: Anaemia is aggravated by the coexistence of chronic kidney disease (CKD) in patients infected with human immunodeficiency virus (HIV). Darbepoetin alfa effectively alleviates CKD-associated anaemia with less frequent dosing than recombinant human erythropoietin (EPO). The current study aimed to determine the efficacy, safety and cost-effectiveness of darbepoetin alfa compared with erythropoietin alfa (EPO-alfa) for treatment of anaemia in HIV-infected subjects receiving haemodialysis. METHODS: An open label, single arm, prospective study of 12 haemodialysis subjects with HIV infection was conducted for a duration of 6 months after switching from intravenous (i.v.) EPO-alfa two/three times weekly to i.v. darbepoetin alfa once weekly. The primary end point was the proportion of patients maintaining haemoglobin (Hb) levels>or=11 g/dl while a weekly dose of darbepoetin alfa was a secondary end point. RESULTS: Darbepoetin alfa, as effectively as EPO-alfa maintained the proportion of the subjects having Hb levels>or=11 g/dl at an average weekly dose of 40.60 microg compared with an equivalent dose of 51.84 microg for EPO-alfa. Antiretroviral therapy and HIV infection stage remained the same for each specific patient throughout the study period, including the last 6 months of EPO-alfa therapy. No difference in the incidence of adverse effects was observed after switching from EPO-alfa to darbepoietin alfa. CONCLUSIONS: Lower doses of darbepoetin alfa at extended dosing interval is as safe and effective as EPO-alfa for treating anaemia, suggesting that darbepoetin alfa is a more cost-effective therapeutic alternative to EPO-alfa in the management of anaemia associated with HIV infection in subjects receiving haemodialysis.     

Darbepoetin alfa administered monthly maintains haemoglobin concentrations in patients with chronic kidney disease not receiving dialysis: a multicentre, open-label, Australian study

AIM: Darbepoetin alfa, an erythropoiesis-stimulating protein, has a longer serum half-life than recombinant human erythropoietin, allowing less-frequent administration. This study aimed to demonstrate that once-monthly (QM) darbepoetin alfa administration would maintain haemoglobin (Hb) concentrations in subjects with chronic kidney disease (CKD) not receiving dialysis who had previously been administered darbepoetin alfa every 2 weeks (Q2W). METHODS: This was a multicentre study in which subjects with CKD receiving stable Q2W darbepoetin alfa doses and with stable Hb (100-130 g/L) were started on QM darbepoetin alfa dosing. The initial QM darbepoetin alfa dose was equivalent to the cumulative darbepoetin alfa dose administered during the month preceding enrollment. Darbepoetin alfa doses were titrated to maintain Hb concentrations between 100 and 130 g/L. The primary endpoint was the proportion of subjects maintaining mean Hb >or= 100 g/L during the evaluation period (weeks 21-33). RESULTS: Sixty-six subjects were enrolled in the study and all received at least one dose of darbepoetin alfa; 55 (83%) had mean Hb >or= 100 g/L during evaluation. Mean (SD) Hb concentrations at baseline and during the evaluation period were 119 (8.7) g/L and 114 (9.8) g/L, respectively. The median QM darbepoetin alfa dose at baseline and during the evaluation period was 80 microg. Darbepoetin alfa was considered to be well-tolerated. CONCLUSION: Patients with CKD not receiving dialysis who are receiving darbepoetin alfa Q2W can be safely and effectively extended to darbepoetin alfa QM. Dosing QM may simplify anaemia management for patients and health-care providers.     

A trial of subcutaneous administration of darbepoetin alfa once every other week for the treatment of anemia in peritoneal dialysis patients

BACKGROUND: Darbepoetin alfa (Aranesp, Amgen) is an erythropoietic stimulating protein with a three fold longer terminal half life than recombinant human erythropoietin (rHuEPO). The purpose of this single center, single arm study was to determine whether darbepoetin alfa is as effective as rHuEPO for the treatment of renal anemia in patients on peritoneal dialysis when administered at a reduced dosing frequency of once every other week irrespective of the initial rHuEPO dose frequency. METHODS: A total of 17 patients on peritoneal dialysis receiving stable rHuEPO therapy were changed to darbepoetin alfa every other week, using the recommended 200:1 conversion factor . The doses of darbepoetin alfa were titrated to maintain hemoglobin within -1.0 to +1.5 g/dL of the patients' baseline value and also within a range of 10.0 to 13.0 g/dL for up to 24 weeks (20 weeks dose titration period followed by 4 week evaluation period). The primary end point was change in hemoglobin levels between baseline and evaluation period. RESULTS: Mean change in hemoglobin levels from baseline to evaluation period was 0.03 g/dL (95% CI -0.62 to +0.69). This was not a statistically significant or clinically relevant difference, despite the reduced frequency of darbepoetin alfa administration. There were no serious or major adverse effects observed with darbepoetin alfa during the study. CONCLUSION: These results show that darbepoetin alfa maintains hemoglobin concentrations effectively and safely in patients on peritoneal dialysis, but with a reduced dose frequency as compared to rHuEPO.     

Darbepoetin alfa (Aranesp) in children with chronic renal failure

BACKGROUND: Darbepoetin alfa use has been reported in 7 children with chronic renal failure (CRF). Our objective was to evaluate the efficacy and safety of darbepoetin and determine a therapeutic dose in a larger sample of children with CRF. METHODS: Twenty-six children with chronic renal insufficiency (CRI) GFR <30 mL/min/1.73 m(2), on peritoneal dialysis (PD) or hemodialysis (HD) entered a prospective, open-label study of darbepoetin. Seven ineligible children who underwent the same evaluation were analyzed retrospectively. The starting dose was 0.45 microg/kg/week. IRB/REB approval and informed consent were obtained. The primary outcome measure was hemoglobin (Hb) response within a target range of 10.0 to 12.5 g/dL between 8 and 12 and 20 and 28 weeks. RESULTS: Thirty-three children (15 CRI, 9 HD, 9 PD; aged 1-17 years) were enrolled in the study. Ten patients dropped out (3 before 12 weeks and 7 before 28 weeks), none due to darbepoetin. Mean Hbs were 11.8 and 11.4 between weeks 8 and 12 and 20 and 28, respectively; the proportion of patients with Hb values >10.0 g/dL was 97% and 91% in the same intervals. No effect of grouping patients into CRI, HD, or PD or prospective versus retrospective was observed. One of 13 serious adverse events (hypertension) was possibly related to darbepoetin; 8/14 children reported injection-site pain. At 12 and 28 weeks, respectively, 73% and 87% were receiving darbepoetin less than once weekly. CONCLUSION: A dose approximating 0.5 microg/kg/week of darbepoetin effectively treats anemia in children with chronic renal failure; for many, this may be proportionately increased and injected less than once weekly.     

Efficacy and safety of once-weekly intravenous epoetin alfa in maintaining hemoglobin levels in hemodialysis patients

BACKGROUND: Although an erythropoiesis-stimulating agent (ESA) is most frequently administered intravenously for treatment of anemia in patients with chronic kidney disease who are on dialysis, few studies have compared the efficacy of different intravenous (i.v.) dosing schedules. METHODS: This multicenter, phase IIIb, open-label, controlled study randomized 289 stable hemodialysis patients to continue with conventional dosing of i.v. epoetin alfa or darbepoetin, or to switch to once-weekly i.v. epoetin alfa at the same cumulative weekly starting dose, to maintain hemoglobin levels at 11.0-13.0 g/dL, and within 1.0 g/dL of the baseline value. Hemoglobin levels and ESA doses were recorded every 4 weeks for 28 weeks. RESULTS: Hemoglobin levels fell significantly and ESA doses increased significantly between baseline and week 28 (mean of week 16-28 values) in the once-weekly epoetin alfa group, compared with the conventional treatment group (p< 0.001). The adjusted difference in mean hemoglobin levels between the groups was 0.73 g/dL (greater than the threshold for therapeutic equivalence of 0.5 g/dL). The changes between groups from baseline was significant at all time points for hemoglobin levels (0.36, 0.46, 0.81, 0.87, 0.78, 0.62 and 0.49 g/dL) and from week 12 for ESA dose (718.5, 1,326.5, 1,732.0, 1,839.7 and 1,959.1 IU/week; p=0.005). Hemoglobin was maintained at the target level in 78% and 84% of patients on conventional dosing, and 67% and 64% of those on once-weekly epoetin alfa in the intention-to-treat (p=0.1) and per protocol (p=0.016) populations, respectively. CONCLUSIONS: This study did not show therapeutic equivalence of once-weekly i.v. epoetin alfa with conventional dosing regimens.     

What is the practical conversion dose when changing from epoetin alfa to darbepoetin outside of clinical trials?

BACKGROUND: The recommended conversion dose for changing from epoetin alfa to darbepoetin alfa is 200 units to 1 microg. However, this may result in the over treatment of uraemic anaemia. METHODS: All in-centre haemodialysis patients (n = 60) were converted from an existing subcutaneous epoetin alfa regimen to weekly intravenous darbepoetin alfa. The protocol for anaemia management included a target haemoglobin (Hb) concentration of 120-130 g/L and a ferritin of 300-600 microg/L. Patient treatments were converted from subcutaneous epoetin alfa to weekly, intravenous darbepoetin alfa at month 0, at a conversion dose of 200 units epoetin alfa to 1 microg darbepoetin. RESULTS: Both Hb and ferritin concentrations remained within the target range, but darbepoetin dosages fell from 50.8 to 42.3 microg/week by month 3 (P = 0.02). The initial conversion factor of 210 units/microg rose to 275 units/microg (P = 0.01) at month 4. No difference in conversion dosage could be determined between patients who were epoetin sensitive (<200 units/kg per week) or resistant (>200 units/kg per week, P = NS). Patients were then switched to fortnightly darbepoetin alfa dosing treatments; the existing weekly dose being doubled and Hb levels fell from 125 to 110 g/L (P < 0.0001), despite an increase in the mean dose from 44.9 to 47.5 microg/week (P = 0.02). CONCLUSION: The original dosage reduction after the switch from epoetin alfa to weekly intravenous darbepoetin alfa may offset the increased relative cost of the latter. When administered weekly and intravenously, darbepoetin alfa maintains Hb at a more favourable conversion rate than is currently recommended.     

Weekly low-dose treatment with intravenous iron sucrose maintains iron status and decreases epoetin requirement in iron-replete haemodialysis patients.

BACKGROUND: Haemodialysis patients need sustained treatment with intravenous iron because iron deficiency limits the efficacy of recombinant human epoetin therapy in these patients. However, the optimal intravenous iron maintenance dose has not been established yet. METHODS: We performed a prospective multicentre clinical trial in iron-replete haemodialysis patients to evaluate the efficacy of weekly low-dose (50 mg) intravenous iron sucrose administration for 6 months to maintain the iron status, and to examine the effect on epoetin dosage needed to maintain stable haemoglobin values in these patients. Fifty patients were enrolled in this prospective, open-label, single arm, phase IV study. RESULTS: Forty-two patients (84%) completed the study. After 6 months of intravenous iron sucrose treatment, the mean ferritin value showed a tendency to increase slightly from 405 +/- 159 at baseline to 490 +/- 275 microg/l at the end of the study, but iron, transferrin levels and transferrin saturation did not change. The haemoglobin level remained stable (12 +/- 1.1 at baseline and 12.1 +/- 1.5 g/dl at the end of the study). The mean dose of darbepoetin alfa could be reduced from 0.75 to 0.46 microg/kg/week; epoetin alfa was decreased from 101 to 74 IU/kg/week; and the mean dose of epoetin beta could be reduced from 148 to 131 IU/kg/week at the end of treatment. CONCLUSIONS: A regular 50 mg weekly dosing schedule of iron sucrose maintains stable iron stores and haemoglobin levels in haemodialysed patients and allows considerable dose reductions for epoetins. Low-dose intravenous iron therapy may represent an optimal approach to treat the continuous loss of iron in dialysis patients.     

Darbepoetin alfa once every 2 weeks for treatment of anemia in dialysis patients: a combined analysis of eight multicenter trials

AIM: Darbepoetin alfa has a longer half-life than epoetin-(EPO) alfa or beta, allowing administration at less frequent intervals for the treatment of renal anemia. The aim of the present analysis was to evaluate the efficacy and tolerability of an every-2-week (Q2W) schedule of darbepoetin alfa in a large cohort of dialysis patients. METHODS: Data were combined from eight similarly designed 24-week phase 3b European studies, in which patients receiving EPO alfa or beta once-weekly were converted to Q2W darbepoetin alfa. Darbepoetin alfa dosage was titrated to maintain hemoglobin (Hb) between 10 and 13 g/dl and efficacy was evaluated during a 4-week evaluation period. RESULTS: In the 1,101 patients assigned to Q2W darbepoetin alfa (i.v., n = 196, s.c., n = 905), mean (SD) Hb levels were 11.53 (0.77) g/dl at baseline and 11.35 (1.04) g/dl at evaluation (mean change in Hb -0.27 g/dl, 95% confidence interval 0.34, -0.20). Hb levels were maintained between 10 and 13 g/dl during evaluation in 85% of patients. Darbepoetin alfa doses were similar at baseline and evaluation, and the i.v. and s.c. routes were associated with similar efficacy and dose requirements. Darbepoetin alfa was well-tolerated. CONCLUSIONS: Q2W darbepoetin alfa is effective in maintaining Hb levels in dialysis patients switched from weekly rHuEPO, regardless of the route of administration and with no notable increase in the weekly equivalent dose.     

Darbepoetin alfa for the treatment of anemia in pediatric patients with chronic kidney disease

Darbepoetin alfa, an erythropoiesis-stimulating glycoprotein, has proved efficacious in the treatment of anemia of chronic kidney disease (CKD) in adult subjects. However, little information is available from pediatric populations. We conducted an open-label, non-inferiority, 28-week study comparing the efficacy of darbepoetin alfa with that of recombinant human erythropoietin (rHuEpo) in pediatric subjects with CKD. Subjects, aged 1–18, who were receiving stable rHuEpo treatment (n=124) were randomized (1:2) to either continue receiving rHuEpo or convert to darbepoetin alfa, with doses titrated to achieve and maintain hemoglobin (Hb) levels between 10.0 and 12.5 g/dl. Darbepoetin alfa was considered to be non-inferior to rHuEpo if the lower limit of the two-sided 95% confidence interval (CI) for the difference in the mean change in Hb between the two treatment groups was above −1.0 g/dl. The adjusted mean change in Hb between the baseline and the evaluation period for the rHuEpo and darbepoetin alfa groups was −0.16 g/dl and 0.15 g/dl, respectively, with a difference of 0.31 g/dl (95% CI: −0.45, 1.07) between the means. These results, and the comparable safety profiles, demonstrate that darbepoetin alfa is non-inferior to rHuEpo in the treatment of anemia in pediatric patients with CKD.