New-Onset Anemia and Associated Risk of ESKD and Death in Non-Dialysis CKD Patients: A Multi-Cohort Observational Study

Haemoglobin trajectories in chronic kidney disease and risk of major adverse cardiovascular events

BACKGROUND

The trajectories of haemoglobin in patients with chronic kidney disease (CKD) have been poorly described. In such patients, we aimed to identify typical haemoglobin trajectory profiles and estimate their risks of major adverse cardiovascular events (MACE).

METHODS

We used 5-year longitudinal data from the CKD-REIN cohort patients with moderate to severe CKD enrolled from 40 nationally representative nephrology clinics in France. A joint latent class model was used to estimate, in different classes of haemoglobin trajectory, the competing risks of (i) MACE + defined as the first event among cardiovascular death, non-fatal myocardial infarction, stroke or hospitalization for acute heart failure, (ii) initiation of kidney replacement therapy (KRT) and (iii) non-cardiovascular death.

RESULTS

During the follow-up, we gathered 33 874 haemoglobin measurements from 3011 subjects (median, 10 per patient). We identified five distinct haemoglobin trajectory profiles. The predominant profile (n = 1885, 62.6%) showed an overall stable trajectory and low risks of events. The four other profiles had nonlinear declining trajectories: early strong decline (n = 257, 8.5%), late strong decline (n = 75, 2.5%), early moderate decline (n = 356, 11.8%) and late moderate decline (n = 438, 14.6%). The four profiles had different risks of MACE, while the risks of KRT and non-cardiovascular death consistently increased from the haemoglobin decline.

CONCLUSION

In this study, we observed that two-thirds of patients had a stable haemoglobin trajectory and low risks of adverse events. The other third had a nonlinear trajectory declining at different rates, with increased risks of events. Better attention should be paid to dynamic changes of haemoglobin in CKD.

The estimated mediating roles of anemia-related variables in the association between kidney function and mortality: a National Health and Nutrition Examination Survey (NHANES) study

Anemia is a common complication of chronic kidney disease (CKD), impacting long-term outcomes such as mortality and morbidity. Analyzing NHANES data from 1999 through 2016 for adults aged ≥ 20 years, we assessed the mediating effects of anemia biomarkers (hemoglobin, hematocrit, red cell distribution width [RDW], and mean corpuscular hemoglobin concentration [MCHC]) on CKD-related outcomes by using hazard ratios from a biomarker-adjusted model. Of 44,099 participants, 7463 experienced all-cause death. Cox proportional hazard models revealed a higher all-cause mortality risk in the > 45 years and CKD groups than in the early CKD group. Hemoglobin, hematocrit and MCHC were inversely related to all-cause mortality; RDW was related to mortality. Single mediation analysis showed greater mediating effects of anemia indicators on CKD and mortality in the elderly (> 65 years) population than those in the general population. In the multimediation analysis, the combined mediating effect of anemia was higher in the CKD population than in the general population. This study showed a proportional increase in the mediating effect of anemia with CKD stage, suggesting potential therapeutic avenues. However, further exploration of other mediating factors on kidney outcomes is necessary.

A novel scenario in the therapeutic management of anemia of chronic kidney disease: placement and use of roxadustat

Anemia is a frequent and early chronic kidney disease (CKD) complication. Its management is currently based on oral or intravenous iron supplements, erythropoiesis-stimulating agents, and red blood cell transfusions, when the benefits of transfusion outweigh the risks. Anemia in CKD patients is underdiagnosed and undertreated. Current standard of care is associated with challenges and therefore new treatment approaches have been sought. Hypoxia-inducible factor-prolyl-hydroxylase enzyme inhibitors are a new class of orally administered drugs used to treat anemia associated with CKD. Small-molecule hypoxia-inducible factor-prolyl-hydroxylase inhibitors have a novel mechanism of action that activates the hypoxia-inducible factor (oxygen-sensing) pathway resulting in a coordinated erythropoietic response, leading to increased endogenous erythropoietin production, improved iron absorption and transport, and reduced hepcidin. Roxadustat is the first hypoxia-inducible factor-prolyl-hydroxylase inhibitor approved by the European Medicines Agency (EMA) and reimbursed in Italy by the Italian Medicines Agency (AIFA) for the treatment of adult patients with symptomatic CKD-related anemia. This authorization was based on the outcome of a globally-conducted phase 3 clinical trial program comprising eight pivotal multicenter randomized studies. In the absence of up-to-date guidelines, we performed a critical appraisal of the placement and use of roxadustat in this therapeutic context.

Efficacy and safety of hypoxia-inducible factor prolyl hydroxylase inhibitors in patients with chronic kidney disease: meta-analysis of phase 3 randomized controlled trials

Background

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new therapeutic agents for anaemia in chronic kidney disease (CKD). We evaluated by meta-analysis and meta-regression the efficacy and safety of HIF-PHIs in patients with CKD-related anaemia.

Methods

We selected phase 3 randomized clinical trials (RCTs) comparing HIF-PHIs and erythropoiesis-stimulating agents (ESAs) in dialysis and non-dialysis patients. Efficacy outcomes were the changes from baseline of haemoglobin, iron parameters (hepcidin, serum iron, TIBC, TSAT, ferritin) and intravenous iron dose; as safety outcomes we considered cancer, adjudicated major adverse cardiovascular events (MACE), MACE+ (MACE plus hospitalization for hearth failure or unstable angina or thromboembolic event), thrombotic events (deep vein thrombosis, pulmonary embolism), arterovenous fistula (AVF) thrombosis and death.

Results

We included 26 RCTs with 24 387 patients. Random effect meta-analysis of the unstandardized mean difference between HIF-PHIs and ESAs showed a significant change in haemoglobin levels from baseline of 0.10 g/dL (95% CI 0.02 to 0.17). Meta-regression analysis showed a significantly higher haemoglobin change for HIF-PHIs in younger patients and versus short-acting ESA (0.21 g/dL, 95% CI 0.12 to 0.29 versus -0.01, 95% CI -0.09 to 0.07 in studies using long-acting ESA, P < .001). No significant effect on heterogeneity was found for type of HIF-PHIs. In comparison with ESAs, HIF-PHIs induced a significant decline in hepcidin and ferritin and a significant increase in serum iron and TIBC, while TSAT did not change; intravenous iron dose was lower with HIF-PHI (-3.1 mg/week, 95% CI -5.6 to -0.6, P = .020). Rate ratio of cancer (0.93, 95% CI 0.76 to 1.13), MACE (1.00, 95% CI 0.94 to 1.07), MACE+ (1.01, 95% CI 0.95 to 1.06), thrombotic events (1.08, 95% CI 0.84 to 1.38), AVF thrombosis (1.02, 95% CI 0.93 to 1.13) and death (1.02, 95% CI 0.95 to 1.13) did not differ between HIF-PHIs and ESAs.

Conclusions

HIF-PHIs at the doses selected for the comparisons are effective in correcting anaemia in comparison with ESA therapy with a significant impact on iron metabolism without notable difference among various agents. No safety signals emerge with use of HIF-PHIs.

Quantitative systems pharmacology model of erythropoiesis to simulate therapies targeting anemia due to chronic kidney disease

Anemia induced by chronic kidney disease (CKD) has multiple underlying mechanistic causes and generally worsens as CKD progresses. Erythropoietin (EPO) is a key endogenous protein which increases the number of erythrocyte progenitors that mature into red blood cells that carry hemoglobin (Hb). Recombinant human erythropoietin (rHuEPO) in its native and re-engineered forms is used as a therapeutic to alleviate CKD-induced anemia by stimulating erythropoiesis. However, due to safety risks associated with erythropoiesis-stimulating agents (ESAs), a new class of drugs, prolyl hydroxylase inhibitors (PHIs), has been developed. Instead of administering exogenous EPO, PHIs facilitate the accumulation of HIF-α, which results in the increased production of endogenous EPO. Clinical trials for ESAs and PHIs generally involve balancing decisions related to safety and efficacy by carefully evaluating the criteria for patient selection and adaptive trial design. To enable such decisions, we developed a quantitative systems pharmacology (QSP) model of erythropoiesis which captures key aspects of physiology and its disruption in CKD. Furthermore, CKD virtual populations of varying severities were developed, calibrated, and validated against public data. Such a model can be used to simulate alternative trial protocols while designing phase 3 clinical trials, as well as an asset for reverse translation in understanding emerging clinical data.

Efficacy and safety of hypoxia-inducible factor-prolyl hydroxylase inhibitor treatment for anemia in chronic kidney disease: an umbrella review of meta-analyses

The objective was to provide a comprehensive summary of existing evidence on the efficacy and safety of hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) for the treatment of anemia in chronic kidney disease (CKD). A systematic search was conducted in the Medline, Embase, and Cochrane databases. Only meta-analyses that evaluated the efficacy and safety of HIF-PHI treatment for anemia in CKD were included. The efficacy outcomes included hemoglobin levels and iron metabolism indices, while the safety outcomes were assessed by examining adverse events. The qualities of methodologies and evidence were assessed using the AMSTAR 2 system and the NutriGrade tool, respectively. Fourteen meta-analyses, comprising 105 distinct comparisons, were included. The comparisons were backed by evidence of high, moderate, and low levels, distributed in approximately equal proportions. None of the studies were deemed to possess a high level of confidence. In both the overall and individual treatment groups of HIF-PHI, there was an increase in the levels of hemoglobin, transferrin, and transferrin saturation, while the levels of hepcidin and total iron binding capacity decreased. Serum ferritin exhibited a reduction to some extent, while serum iron did not show significant alterations following HIF-PHI treatments. There were no notable disparities in safety outcomes between the HIF-PHI and erythropoietin stimulating agents or placebo groups. This umbrella review suggests that HIF-PHI treatment can effectively increase hemoglobin levels in CKD patients and enhance iron metabolism by decreasing hepcidin levels and improving iron transport. The safety profiles of HIF-PHIs were generally comparable to those of ESA therapies or placebos.

The effect of Dipeptidyl peptidase 4 (DPP-4) inhibitors on hemoglobin level in diabetic kidney disease: A retrospective cohort study

Anemia typically develops early in the course of diabetic kidney disease (DKD). There are data to show that dipeptidyl-peptidase-4 (DPP-4) inhibitors affect hematopoietic growth factor activity and hemoglobin level. We retrospectively reviewed 443 DKD patients who were started on DDP-4 inhibitor therapy in 2019. Their hemoglobin level at baseline (6-12 months before treatment), pretreatment (0-6 months before treatment), and post-treatment periods (within 6 months after DPP-4 inhibitor), concomitant estimated glomerular filtration rate (eGFR), HbA1c, peripheral blood white cell and platelet counts were reviewed. The severity of kidney failure was classified according to the Kidney Disease: Improving Global Outcomes stages. The hemoglobin level had a small but significant decline from 11.98 ± 2.07 to 11.87 ± 2.12 g/dL from pretreatment to post-treatment period (paired Student t test, P < .0001). From the pre- to post-treatment period, the decline of hemoglobin level was 0.10 ± 0.89 g/dL, which was significantly less than that from baseline to pretreatment period (0.24 ± 0.90 g/dL, P = .0008). The change in hemoglobin level had a positive correlation with the change in HbA1c level (R = 0.218, P < .0001), but did not correlate with the type of DPP-4 inhibitor or pretreatment eGFR. There was no significant change in peripheral blood white cell or platelet count during the same period. DPP-4 inhibitor ameliorates hemoglobin decline in DKD. The effect of DPP-4 inhibitor on hemoglobin is statistically significant but clinically modest, and did not correlate with the concomitant change in kidney function.

Prevalence, incidence, and treatment of anaemia in patients with non-dialysis-dependent chronic kidney disease: findings from a retrospective real-world study in Italy

BACKGROUND

Limited data are available on the epidemiology and clinical management of anaemia in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD).

METHODS

This retrospective observational study was based on records from databases of five Local Health Units across Italy. Adults with reported NDD-CKD stage 3a-5 between 1 January 2014 and 31 December 2016 were identified. Annual prevalence and incidence of anaemia (age- and sex-standardised) and clinical management (erythropoiesis-stimulating agents [ESAs], intravenous [IV] iron, and blood transfusions) were evaluated. Eligibility for ESAs was defined by ≥ 2 records of Hb < 10 g/dL, or < 11 g/dL over 6 months.

RESULTS

Overall, 101,143 individuals with NDD-CKD (3a-5) recorded between 2014 and 2016 were identified, of whom 40,020 (39.6%) were anaemic. Prevalence of anaemia was 33.8% in 2016 and incidence of anaemia was stable (11.4-12.4%) from 2014 to 2016. Prevalence and incidence of anaemia increased with CKD stage. Among eligible patients, 12.8% with Hb < 11 g/dL and 15.5% with Hb < 10 g/dL received ESAs, and the proportion treated increased with CKD stage. Among ESA-treated patients with at least 2 years of follow up, 18.4% and 19.3% received IV iron in the Hb < 11 and < 10 g/dL groups, respectively, and 16.5% and 19.4% received blood transfusions. Corresponding proportions for the overall anaemic cohort were 9.0% and 11.3%, respectively.

CONCLUSIONS

Anaemia is a significant issue in patients with NDD-CKD. Low rates of ESA treatment indicate a potential treatment gap and suggest that anaemia may not be adequately controlled in many patients.