Randomized cross-over comparison of intravenous and subcutaneous darbepoetin dosing efficiency in haemodialysis patients

Erythropoiesis-stimulating agents for anaemia in adults with chronic kidney disease: a network meta-analysis

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) are commonly used to treat anaemia in people with chronic kidney disease (CKD). However, their use has been associated with cardiovascular events. This is an update of a Cochrane review first published in 2014.

OBJECTIVES

To compare the efficacy and safety of ESAs (epoetin alfa, epoetin beta, darbepoetin alfa, methoxy polyethylene glycol-epoetin beta, and biosimilar ESAs against each other, placebo, or no treatment) to treat anaemia in adults with CKD.

SEARCH METHODS

In this update, we searched the Cochrane Kidney and Transplant Register of Studies up to 29 April 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that included a comparison of an ESA (epoetin alfa, epoetin beta, darbepoetin alfa, methoxy polyethylene glycol-epoetin beta, a biosimilar epoetin or a biosimilar darbepoetin alfa) with another ESA, placebo or no treatment in adults with CKD were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two independent authors screened the search results and extracted data. Data synthesis was performed using random-effects pairwise meta-analysis (expressed as odds ratios (OR) and their 95% confidence intervals (CI)) and network meta-analysis. We assessed for heterogeneity and inconsistency within meta-analyses using standard techniques and planned subgroup and meta-regression to explore sources of heterogeneity or inconsistency. We assessed certainty in treatment estimates for the primary outcomes (preventing blood transfusions and death (any cause)) using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Sixty-two new studies (9237 participants) were included in this update, so the review now includes 117 studies with 25,237 participants. Most studies were at high or unclear risk of bias in most methodological domains. Overall, results remain similar in this update compared to our previous review in 2014. For preventing blood transfusion, epoetin alfa (OR 0.28, 95% CI 0.13 to 0.61; low certainty evidence) and epoetin beta (OR 0.19, 95% CI 0.08 to 0.47; low certainty evidence) may be superior to placebo, and darbepoetin alfa was probably superior to placebo (OR 0.27, 95% CI 0.11 to 0.67; moderate certainty evidence). Methoxy polyethylene glycol-epoetin beta (OR 0.33, 95% CI 0.11 to 1.02; very low certainty evidence), a biosimilar epoetin (OR 0.34, 95% CI 0.11 to 1.03; very low certainty evidence) and a biosimilar darbepoetin alfa (OR 0.37, 95% CI 0.07 to 1.91; very low certainty evidence) had uncertain effects on preventing blood transfusion compared to placebo. The comparative effects of ESAs compared with another ESA on preventing blood transfusions were uncertain, in low to very low certainty evidence. Effects on death (any cause) were uncertain for epoetin alfa (OR 0.79, 95% CI 0.51 to 1.22; low certainty evidence), epoetin beta (OR 0.69, 95% CI 0.40 to 1.20; low certainty evidence), methoxy polyethylene glycol-epoetin beta (OR 1.07, 95% CI 0.67 to 1.71; very low certainty evidence), a biosimilar epoetin (OR 0.80, 95% CI 0.47 to 1.36; low certainty evidence) and a biosimilar darbepoetin alfa (OR 1.63, 95% CI 0.51 to 5.23; very low certainty evidence) compared to placebo. There was probably no difference between darbepoetin alfa and placebo on the odds of death (any cause) (OR 0.99, 95% CI 0.81 to 1.21; moderate certainty evidence). The comparative effects of ESAs compared with another ESA on death (any cause) were uncertain in low to very low certainty evidence. Epoetin beta probably increased the odds of hypertension when compared to placebo (OR 2.17, 95% CI 1.17 to 4.00; moderate certainty evidence). Compared to placebo, epoetin alfa (OR 2.10, 95% CI 1.22 to 3.59; very low certainty evidence), darbepoetin alfa (OR 1.88, 95% CI 1.12 to 3.14; low certainty evidence) and methoxy polyethylene glycol-epoetin beta (OR 1.98, 95% CI 1.05 to 3.74; low certainty evidence) may increase the odds of hypertension, but a biosimilar epoetin (OR 1.88, 95% CI 0.96 to 3.67; low certainty evidence) and biosimilar darbepoetin alfa (OR 1.98, 95% CI 0.84 to 4.66; low certainty evidence) had uncertain effects on hypertension. The comparative effects of all ESAs compared with another ESA, placebo or no treatment on cardiovascular death, myocardial infarction, stroke, vascular access thrombosis, kidney failure, and breathlessness were uncertain. Network analysis for fatigue was not possible due to sparse data.  AUTHORS' CONCLUSIONS: The comparative effects of different ESAs on blood transfusions, death (any cause and cardiovascular), major cardiovascular events, myocardial infarction, stroke, vascular access thrombosis, kidney failure, fatigue and breathlessness were uncertain.

International Anemia Prevalence and Management in Peritoneal Dialysis Patients

Background:The optimal treatment for managing anemia in peritoneal dialysis (PD) patients and best clinical practices are not completely understood. We sought to characterize international variations in anemia measures and management among PD patients.Methods:The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) enrolled adult PD patients from 6 countries from 2014 to 2017. Hemoglobin (Hb), ferritin levels, and transferrin saturation (TSAT), as well as erythropoiesis stimulating agents (ESAs) and iron use were compared cross-sectionally at study enrollment in Australia and New Zealand (A/NZ), Canada, Japan, the United Kingdom (UK), and the United States (US).Results:Among 3,603 PD patients from 193 facilities, mean Hb ranged from 11.0 - 11.3 g/dL across countries. The majority of patients (range 53% - 59%) had Hb 10 - 11.9 g/dL, with 4% - 12% patients ≥ 13 g/dL and 16% - 23% < 10 g/dL. Use of ESAs was higher in Japan (94% of patients) than elsewhere (66% - 79% of patients). In the US, 63% of patients had a ferritin level > 500 ng/mL, compared with 5% - 38% in other countries. In the US and Japan, 87% - 89% of PD patients had TSAT ≥ 20%, compared with 73% - 76% in other countries. Intravenous (IV) iron use within 4 months of enrollment was higher in the US (55% of patients) than elsewhere (6% - 17% patients).Conclusions:In this largest international observational study of anemia and anemia management in patients receiving PD, comparable Hb levels across countries were observed but with notable differences in ESA and iron use. Peritoneal dialysis patients in the US have higher ferritin levels and higher IV iron use than other countries.

Darbepoetin for the anaemia of chronic kidney disease

BACKGROUND

Erythropoiesis-stimulating agents are used to treat anaemia in people with chronic kidney disease (CKD). Several agents are available including epoetin alfa or beta as well as agents with a longer duration of action, darbepoetin alfa and methoxy polyethylene glycol-epoetin beta.

OBJECTIVES

To assess the benefits and harms of darbepoetin alfa to treat anaemia in adults and children with CKD (stages 3 to 5, 5D, and kidney transplant recipients).

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (to 13 January 2014) through contact with the Trials' Search Co-ordinator using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE and EMBASE.

SELECTION CRITERIA

We included randomised controlled trials of any darbepoetin alfa treatment of at least three months duration in adults or children with CKD (any stage).

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent investigators. Patient-centred outcomes (need for blood transfusion, iron therapy, progression of kidney disease, total and cardiovascular mortality, cardiovascular events, cancer, hypertension, seizures, and health-related quality of life) and other outcomes (haemoglobin levels) were assessed using random effects meta-analysis. We calculated risk ratios for dichotomous outcomes and mean differences for continuous outcomes, both with 95% confidence intervals.

MAIN RESULTS

We identified 32 studies comprising 9414 participants; 21 studies in 8328 participants could be included in our meta-analyses. One study (4038 participants) compared darbepoetin alfa to placebo, 16 studies (2955 participants) compared darbepoetin alfa to epoetin alfa or beta, four studies (1198 participants) compared darbepoetin alfa to methoxy polyethylene glycol-epoetin beta, three studies (420 participants) compared more frequent with less frequent darbepoetin alfa administration and four studies (303 participants) compared intravenous with subcutaneous darbepoetin alfa administration.In a single large study, darbepoetin alfa reduced the need for blood transfusion and iron therapy compared with placebo in adults with CKD stage 3 to 5, but had little or no effect on survival, increased risks of hypertension, and had uncertain effects on quality of life. Data comparing darbepoetin alfa with epoetin alfa or beta or methoxy polyethylene glycol-epoetin beta were sparse and inconclusive. Comparisons of differing dosing schedules and routes of administration were compared in small numbers of participants and studies. Evidence for treatment effects of darbepoetin alfa were particularly limited for children with CKD, adults with CKD stage 5D, and recipients of a kidney transplant.Studies included in this review were generally at high or unclear risk of bias for all items (random sequence generation, allocation concealment, incomplete outcome data, blinding of participants and personnel, blinding of outcome assessment, selective outcome reporting, intention to treat analysis and other sources of bias). One large study comparing darbepoetin alfa with placebo was at low risk of bias for most items assessed.

AUTHORS' CONCLUSIONS

Data suggest that darbepoetin alfa effectively reduces need for blood transfusions in adults with CKD stage 3 to 5, but has little or no effect on mortality or quality of life. The effects of darbepoetin alfa in adults with CKD stage 5D and kidney transplant recipients and children with CKD remain uncertain as do the relative benefits and harms of darbepoetin alfa compared with other ESAs (epoetin alfa or beta and methoxy polyethylene glycol-epoetin beta).

International trends in erythropoietin use and hemoglobin levels in hemodialysis patients

Hemoglobin levels and the dose of erythropoiesis-stimulating agents (ESAs) have risen over time in hemodialysis patients within the United States. There are concerns that these trends may be driven by reimbursement policies that provide potential incentives to increase this use. To determine this we studied trends in the use of ESA and hemoglobin levels in hemodialysis patients and the relationship of these trends to the mode of reimbursement. Using the Dialysis Outcomes and Practice Patterns Study (DOPPS) database of hemodialysis we analyzed facility practices in over 300 randomly selected dialysis units in 12 countries. At each of three phases (years 1996-2001, 2002-2004, and 2005-present), we randomly selected over 7500 prevalent hemodialysis, hemofiltration, or hemodiafiltration patients. ESA usage rose significantly in every country studied except Belgium. All but Sweden demonstrated a substantial increase in hemoglobin levels. In 2005 more than 40% of patients had hemoglobin levels above the KDOQI upper target limit of 120 g/l in all but Japan. These trends appeared to be independent of the manner of reimbursement even though the United States is the only country with significant financial incentives promoting increased use of these agents. Thus, our study found that prescribing higher doses of ESAs and achieving higher hemoglobin levels by physicians reflects a broad trend across DOPPS countries regardless of the reimbursement policies.

A meta-analysis of the relative doses of erythropoiesis-stimulating agents in patients undergoing dialysis

Background. Erythropoiesis-stimulating agents (ESAs) such as epoetin alfa and beta, and darbepoetin alfa have improved the management of anaemia secondary to chronic kidney disease. Numerous studies have reported a dose reduction when patients receiving dialysis were converted from epoetin to darbepoetin alfa using the starting dose conversion of 200:1 as indicated on the prescribing label by the European Medicines Agency. The objective of this meta-analysis was to summarize the existing body of scientific evidence to evaluate the potential dose savings when comparing epoetin alfa or beta to darbepoetin alfa. Method. Medline and EmBase were searched to identify all published trials investigating ESA treatment in anaemic patients receiving dialysis and converted from epoetins to darbepoetin alfa. We selected prospective randomized controlled, non-randomized and observational studies involving patients on dialysis that compared epoetin and darbepoetin alfa dosing. Results. Of 573 articles identified, 9 studies met the eligibility criteria and were included in our analysis. The overall percentage dose savings attained when dialysis patients were converted from epoetin to darbepoetin alfa was 30% (range: 4%-44%). Greater dose savings were noted with intravenous administration (33%) compared with subcutaneous (27%) and between switch-over studies (31%) and RCTs (27%). In all studies, target haemoglobin levels were maintained before and after conversion. Conclusion. This meta-analysis demonstrates that when using an initial 200:1 conversion ratio, as indicated on the European label, from epoetin to darbepoetin, a subsequent reduction in dose was observed and an average 30% dose savings could be achieved.

Randomized Equivalence Study Evaluating the Possibility of Switching Hemodialysis Patients Receiving Subcutaneous Human Erythropoietin Directly to Intravenous Darbepoetin Alfa

Background:

Darbepoetin alfa is an erythropoiesis-stimulating agent (ESA) used either intravenously or subcutaneously with no dose penalty; however, the direct switch from subcutaneous recombinant human erythropoietin (rHuEPO) to intravenous darbepoetin has barely been studied.

Objective:

To establish the equivalence of a direct switch from subcutaneous rHuEPO to intravenous darbepoetin versus an indirect switch from subcutaneous rHuEPO to intravenous darbepoetin after 2 months of subcutaneous darbepoetin in patients undergoing hemodialysis.

Methods:

In this open, randomized, 6-month, prospective study, patients with end-stage kidney disease who were on hemodialysis were randomized into 2 groups: direct switch from subcutaneous rHuEPO to intravenous darbepoetin (group 1) and indirect switch from subcutaneous rHuEPO to intravenous darbepoetin after 2 months of subcutaneous darbepoetin (group 2). A third, nonrandomized group (control), consisting of patients treated with intravenous rHuEPO who were switched to intravenous darbepoetin, was also studied to reflect possible variations of hemoglobin (Hb) levels due to change from one type of ESA to the other. The primary outcome was the proportion of patients with stable Hb levels at month 6. Secondary endpoints included Hb stability at month 3, dosage requirements for darbepoetin, and safety of the administration route.

Results:

Among 154 randomized patients, the percentages with stable Hb levels were equivalent in groups 1 and 2, respectively, at month 3 (86.0% vs 91.3%) and month 6 (82.1% vs 81.6%; difference –0.5 [90% CI –12.8 to 11.8]). Mean Hb levels between baseline and month 6 remained stable in both groups, with no variation in mean darbepoetin dose. Mean ferritin levels remained above 100 μg/L in the 3 groups during the whole study, and darbepoetin was well tolerated.

Conclusions:

This study has shown equivalent efficacy on Hb stability without the need for dosage increase in patients switched directly from subcutaneous rHuEPO to intravenous darbepoetin.

A comparison of haemoglobin levels and doses in haemodialysis patients treated with subcutaneous or intravenous darbepoetin alfa: a German prospective, randomized, multicentre study

BACKGROUND

The different efficacy of subcutaneous and intravenous rHuEPO results in higher doses and costs in intravenously treated patients. Darbepoetin alfa has a different pharmacokinetic profile compared to rHuEPO, and previous clinical experience suggests that subcutaneous and intravenous darbepoetin alfa may have similar efficacy. Objective. The aim of this study was to compare the efficacy of intravenous and subcutaneous darbepoetin alfa regarding haemoglobin levels and doses.

METHODS

Patients treated with subcutaneous darbepoetin alfa for at least 6 months were randomized 1:1 to continue with subcutaneous treatment of darbepoetin alfa or to switch to the intravenous administration route. The application frequency was not altered. Darbepoetin alfa dose as well as haemoglobin concentrations were evaluated as per patient average at baseline (Week -3 +/- 1), Week 24 +/- 3 and Week 48 +/- 3.

RESULTS

One hundred fourteen patients in 9 German dialysis centres were included. Fifty-three patients were treated intravenously and 61 patients continued the subcutaneous therapy. Mean haemoglobin levels and mean weekly darbepoetin alfa dose did not change significantly in either treatment group.

CONCLUSIONS

Our data suggest that the darbepoetin alfa dose can be kept constant if patients are switched from subcutaneous to intravenous treatment.

New agents that stimulate erythropoiesis

Recombinant human erythropoietin (rhEpo) has proven to be remarkably safe and effective for treatment of anemias, primarily those secondary to renal disease and malignancy. Despite the worldwide use of rhEpo, concerns about its cost, the need for frequent parenteral administration, and the development of anti-Epo antibodies have prompted development of improved agents to stimulate erythropoiesis. Three strategies appear to be particularly promising. The half-life of Epo in the circulation can be prolonged by the addition of N-linked carbohydrate groups, by formation of adducts with polyethylene glycol, and by preparation of Epo multimers. Second, mimetic peptides can effectively trigger signal transduction at the Epo receptor, thereby boosting red-cell production. Finally, the hypoxia inducible transcription factor (HIF) can be pharmacologically induced by oral agents, resulting in enhanced expression not only of endogenous Epo but also of other genes important in the regulation of erythropoiesis.

[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.

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.

Clinical implications of converting stable haemodialysis patients from subcutaneous to intravenous administration of darbepoetin alfa

BACKGROUND

The erythropoiesis-stimulating protein darbepoetin alfa (Aranesp) can be given intravenously (i.v.) or subcutaneously (s.c.). Despite a s.c. bioavailability of only 37%, darbepoetin alfa i.v. or s.c. dose requirements were comparable in previous studies designed to evaluate other aspects of anaemia treatment. The present study was designed to compare i.v. vs s.c. dose requirements.

METHODS

A single-centre open-label, prospective and randomized crossover study was undertaken in 71 stable haemodialysis patients. After a run-in period randomized to a 20 week study treatment with either s.c. or i.v. darbepoetin alfa, the patients were crossed over to the other treatment modality for another 20 week study period. The unit dose of weekly darbepoetin alfa was adjusted to maintain each patient's haemoglobin within a target range of -0.8 to +0.8 mmol/l of the individual baseline haemoglobin and between 6.8 and 8.5 mmol/l throughout the study period. The primary endpoint was the mean dose of darbepoetin alfa necessary to maintain the haemoglobin level in the defined range.

RESULTS

Data from 58 patients were available for analysis. Haemoglobin concentrations were maintained effectively in subjects, regardless of whether they received darbepoetin alfa i.v. or s.c.. The overall mean difference in haemoglobin levels during s.c. or i.v. was 0.052 mmol/l (95% confidence interval: -0.132 to 0.236 mmol/l). The difference had no statistical or clinical significance. The population mean darbepoetin alfa dose during i.v. treatment was 32.1 microg/week, compared with a mean value for s.c. treatment of 34.1 microg/week. A paired two-tailed ratio t-test showed that P = 0.036, indicating a 95% probability of a mean dose reduction between 1.2% and 28% by i.v. treatment instead of s.c..

CONCLUSIONS

Renal anaemia of stable haemodialysis patients can be treated with darbepoetin alfa more effectively by the i.v. as compared with the s.c. route.