Early low-dose erythropoiesis-stimulating agent therapy and progression of moderate chronic kidney disease: a randomized, placebo-controlled trial

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.

Evolving Strategies in the Treatment of Anaemia in Chronic Kidney Disease: The HIF-Prolyl Hydroxylase Inhibitors

Chronic kidney disease (CKD) affects approximately 10% of the worldwide population; anaemia is a frequent complication. Inadequate erythropoietin production and absolute or functional iron deficiency are the major causes. Accordingly, the current treatment is based on iron and erythropoiesis stimulating agents (ESAs). Available therapy has dramatically improved the management of anaemia and the quality of life. However, safety concerns were raised over ESA use, especially when aiming to reach near-to-normal haemoglobin levels with high doses. Moreover, many patients show hypo-responsiveness to ESA. Hypoxia-inducible factor (HIF) prolyl hydroxylase domain (PHD) inhibitors (HIF-PHIs) were developed for the oral treatment of anaemia in CKD to overcome these concerns. They simulate the body's exposure to moderate hypoxia, stimulating the production of endogenous erythropoietin. Some molecules are already approved for clinical use in some countries. Data from clinical trials showed non-inferiority in anaemia correction compared to ESA or superiority for placebo. Hypoxia-inducible factor-prolyl hydroxylase domain inhibitors may also have additional advantages in inflamed patients, improving iron utilisation and mobilisation and decreasing LDL-cholesterol. Overall, non-inferiority was also shown in major cardiovascular events, except for one molecule in the non-dialysis population. This was an unexpected finding, considering the lower erythropoietin levels reached using these drugs due to their peculiar mechanism of action. More data and longer follow-ups are necessary to better clarifying safety issues and further investigate the variety of pathways activated by HIF, which could have either positive or negative effects and could differentiate HIF-PHIs from ESAs.

The interaction between post-transplant anemia and allograft function in kidney transplantation: The Japan Academic Consortium of Kidney Transplantation-II study

BACKGROUND

The interaction between post-transplant anemia (PTA) and allograft function in kidney transplantation has not been evaluated directly. PTA, defined by WHO/AST criteria, was investigated in 1307 adult kidney transplant recipients between 2000 and 2015 (median follow-up, 7 years).

METHODS

We investigated the impact of hemoglobin (Hb) on graft failure (non-censored for death) and their interactions, time-dependent Cox model, and subgroup analysis were used.

RESULTS

PTA prevalence was 43.6% at 7 years and varied according to allograft function, recipient sex, and follow-up period. Decreased Hb considering the time-varying effect was associated with an increased risk of graft failure (hazard ratio = 1.83, 95% CI 1.66-2.02, P < 0.001). In subgroup analysis, allograft function (post-transplant time-averaged estimated glomerular filtration rate and cut point: 45 mL/min/1.73 m²) had significant interaction (P = 0.032). The 7-year graft failure rate in recipients with PTA and high eGFR was 7.7% (HR 1.52, 95% CI 1.25-1.84), whereas in those with PTA and low eGFR was 19.9% (HR 2.00, 95% CI 1.74-2.31).

CONCLUSIONS

The unfavorable impact of PTA was significantly enhanced by low allograft function. PTA is likely to be associated with graft failure due to interaction with allograft function. Therefore, we should consider both Hb level and allograft function while determining the treatment strategy.

Continuous erythropoiesis receptor activator (CERA) for the anaemia of chronic kidney disease

BACKGROUND

Continuous erythropoiesis receptor activator (CERA) is a newer, longer acting ESA which might be preferred to other ESAs (epoetin or darbepoetin) based on its lower frequency of administration. Different dosing requirements and molecular characteristics of CERA compared with other ESAs may lead to different health outcomes (mortality, cardiovascular events, quality of life) in people with anaemia and chronic kidney disease (CKD).

OBJECTIVES

To assess benefits and harms of CERA compared with other epoetins (darbepoetin alfa and epoetin alfa or beta) or placebo/no treatment or CERA with differing strategy of administration for anaemia in individuals with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 13 June 2017 through contact with the Information Specialist 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; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least three months' duration, comparing CERA with a different ESA (darbepoetin alfa or epoetin alfa or beta) or placebo or standard care or versus CERA with different strategies for administration in people with any stage of CKD.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent investigators. We summarised patient-centred outcomes (all-cause and cardiovascular mortality, major adverse cardiovascular events, red cell blood transfusion, iron therapy, cancer, hypertension, seizures, dialysis vascular access thrombosis, drug injection-related events, hyperkalaemia and health-related quality of life and haemoglobin levels) using random effects meta-analysis. Treatment estimates were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean differences or standardized mean difference with 95% CI for continuous outcomes.

MAIN RESULTS

We included 27 studies involving 5410 adults with CKD. Seven studies (1273 participants) involved people not requiring dialysis, 19 studies (4209 participants) involved people treated with dialysis and one study (71 participants) evaluated treatment in recipients of a kidney transplant. Treatment was given for 24 weeks on average. No data were available for children with CKD. Studies were generally at high or unclear risk of bias from allocation concealment and blinding of outcomes. Only two studies masked participants and investigators to treatment allocation. One study compared CERA with placebo, nine studies CERA with epoetin alfa or beta, nine studies CERA with darbepoetin alfa, and two studies compared CERA with epoetin alfa or beta and darbepoetin alfa. Three studies assessed the effects of differing frequencies of CERA administration and five assessed differing CERA doses.There was low certainty evidence that CERA had little or no effects on mortality (RR 1.07, 95% CI 0.73 to 1.57; RR 1.11, 95% CI 0.75 to 1.65), major adverse cardiovascular events (RR 5.09, 95% CI 0.25 to 105.23; RR 5.56, 95% CI 0.99 to 31.30), hypertension (RR 1.01, 95% CI 0.75 to 1.37; RR 1.00, 95% CI 0.79 to 1.28), need for blood transfusion (RR 1.02, 95% CI 0.72 to 1.46; RR 0.94, 95% CI 0.55 to 1.61), or additional iron therapy (RR 1.03, 95% CI 0.91 to 1.15; RR 0.99, 95% CI 0.95 to 1.03) compared to epoetin alfa/beta or darbepoetin alfa respectively. There was insufficient evidence to compare the effect of CERA to placebo on clinical outcomes. Only one low quality study reported that CERA compared to placebo might lead to little or no difference in the risk of major cardiovascular events (RR 2.97, 95% CI 0.31 to 28.18) and hypertension ((RR 0.73, 95% CI 0.35 to 1.52). There was low certainty evidence that different doses (higher versus lower) or frequency (twice versus once monthly) of CERA administration had little or no different effect on all-cause mortality (RR 3.95, 95% CI 0.17 to 91.61; RR 0.97, 95% CI 0.56 to 1.66), hypertension (RR 0.45, 95% CI 0.08 to 2.52; RR 0.85, 95% CI 0.60 to 1.21), and blood cell transfusions (RR 4.16, 95% CI 0.89 to 19.53; RR 0.91, 95% CI 0.51 to 1.62). No studies reported comparative treatment effects of different ESAs on health-related quality of life.

AUTHORS' CONCLUSIONS

There is low certainty evidence that CERA has little or no effects on patient-centred outcomes compared with placebo, epoetin alfa or beta or darbepoetin alfa for adults with CKD. The effects of CERA among children who have CKD have not studied in RCTs.