Randomized trial to compare the dosage of darbepoetin alfa by administration route 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.

Pharmacokinetic and pharmacodynamic considerations on the erythropoietin effect and adverse events of darbepoetin

INTRODUCTION

In the TREAT and RED-HF trials, patients who received a high darbepoetin dose had an increased risk of adverse events. To find an explanation, the published literature was analyzed on the pharmacokinetics and pharmacodynamics of darbepoetin.

AREAS COVERED

Based on the sigmoid Emax model, the concentration producing 50% of the maximum erythropoietin effect is reported as CE50 = 0.41 ng/ml and the Hill coefficient as H = 3.0 for darbepoetin. Accordingly, a pharmacodynamics-based threshold concentration can be estimated with CE05 = 0.153 ng/ml producing 5% of Emax and a ceiling concentration with CE95 = 1.098 ng/ml producing 95% of Emax, respectively.

EXPERT OPINION

Darbepoetin trough levels should not be less than the threshold concentration but peak levels above the ceiling concentration could be associated with an increased risk of adverse events. The time span associated with the concentration fluctuation between the ceiling and the threshold concentration is estimated with 236 h (= 2.84 times elimination half-life of 83 h) and shorter than the 336 h when dosing every other week. According to such time-dependent pharmacodynamics, a weekly dosing regimen might be more effective and associated with less adverse events than higher doses every other week in patients with suboptimal response to a normal darbepoetin dose.

Frequency of administration of erythropoiesis-stimulating agents for the anaemia of end-stage kidney disease in dialysis patients

BACKGROUND

The benefits of erythropoiesis-stimulating agents (ESA) for dialysis patients have been demonstrated. However, it remains unclear whether the efficacy and safety of new, longer-acting ESA given less frequently is equivalent to recombinant human erythropoietin (rHuEPO) preparations. This is an update of a review first published in 2002 and last updated in 2005.

OBJECTIVES

This review aimed to establish the optimal frequency of ESA administration in terms of effectiveness (correction of anaemia, and freedom from adverse events) and efficiency (optimal resource use) of different ESA dose regimens.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 21 March 2013 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised control trials (RCTs) comparing different frequencies of ESA administration in dialysis patients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Results were expressed as risk ratio (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) was used. Statistical analyses were performed using the random-effects model.

MAIN RESULTS

This review included 33 studies (5526 participants), 22 of which were added for this update. Risk of bias was generally high; only nine studies were assessed at low risk of bias for sequence generation and 14 studies for allocation concealment. Although only four studies were placebo-controlled, all were considered to be at low risk of performance or detection bias because the primary outcome of haemoglobin level was a laboratory-derived assessment and unlikely to be influenced by lack of blinding. We found that 16 studies were at low risk of attrition bias and five were at low risk of selection bias; only one study reporting sources of support was not funded by a pharmaceutical company.We compared four different interventions: Continuous erythropoietin receptor agonists (CERA) versus other ESA (darbepoetin or rHuEPO); different frequencies of darbepoetin administration; darbepoetin versus rHuEPO; and different frequencies of rHuEPO administration.There were no significant differences in maintaining final haemoglobin between CERA administered at two weekly intervals (4 studies, 1762 participants: MD 0.08 g/dL, 95% CI -0.04 to 0.21) or four weekly intervals (two studies, 1245 participants: MD -0.03 g/dL, 95% CI -0.17 to 0.12) compared with rHuEPO administered at two to three weekly intervals. In one study comparing CERA administered every two weeks with darbepoetin administered once/week, there was no significant difference in final haemoglobin (313 participants: MD 0.30 g/dL, 95% CI 0.05 to 0.55). In comparisons of once/week with once every two weeks darbepoetin (two studies, 356 participants: MD 0.04 g/dL, 95% CI -0.45 to 0.52) and once every two weeks with monthly darbepoetin (one study, 64 participants: MD 0.40 g/dL, 95% CI -0.37 to 1.17) there were no significant differences in final haemoglobin levels. There was marked heterogeneity among studies comparing weekly darbepoetin with once every two weeks and was possibly related to different administration protocols. Eight studies compared weekly darbepoetin with rHuEPO given two to three times/week; no statistical difference in final haemoglobin was demonstrated (6 studies, 1638 participants: MD 0.02 g/dL, 95% CI -0.09 to 0.12). Fourteen studies compared different frequencies of rHuEPO. No statistical difference was demonstrated in final haemoglobin (7 studies, 393 participants: SMD -0.17 g/dL, 95% CI -0.39 to 0.05). Adverse events did not differ significantly within comparisons; however, mortality and quality of life were poorly reported, particularly in earlier publications.

AUTHORS' CONCLUSIONS

Longer-acting ESA (darbepoetin and CERA) administered at one to four week intervals are non-inferior to rHuEPO given one to three times/week in terms of achieving haemoglobin targets without any significant differences in adverse events in haemodialysis patients. Additional RCTs are required to evaluate different frequencies of ESA in peritoneal and paediatric dialysis patients and to compare different longer-acting ESA (such as darbepoetin compared with CERA).

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).