Hypoxia-inducible factor stabilisers for the anaemia of chronic kidney disease

Consensus commentary and position of the Italian Society of Nephrology on KDIGO controversies conference on novel anemia therapies in chronic kidney disease

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new drugs developed for the treatment of anemia associated with chronic kidney disease (CKD). This class of drugs stimulates endogenous erythropoietin production and, at the same time, improves iron absorption and mobilization of iron stores (less evident with daprodustat, vadadustat and enarodustat). Several studies have been published in the last few years showing that these agents are not inferior to standard therapy in correcting anemia associated with CKD. The efficacy of HIF-PHIs is coupled with a safety profile comparable to that of standard erythropoiesis stimulating agent (ESA) treatment. However, studies with HIF-PHIs were not long enough to definitively exclude the impact of new drugs on adverse events, such as cancer, death and possibly cardiovascular events, that usually occur after a long follow-up period. Kidney Disease: Improving Global Outcomes (KDIGO) recently reported the conclusions of the Controversies Conference on HIF-PHIs held in 2021. The goal of the present position paper endorsed by the Italian Society of Nephrology is to better adapt the conclusions of the latest KDIGO Conference on HIF-PHIs to the Italian context by reviewing the efficacy and safety of HIF-PHIs as well as their use in subpopulations of interest as emerged from more recent publications not discussed during the KDIGO Conference.

Daprodustat: A Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitor for Anemia of Chronic Kidney Disease

OBJECTIVE

The objective was to review the safety and efficacy of daprodustat, a hypoxia-inducible factor-prolyl hydroxylase inhibitor (HIF-PHI) in the treatment of anemia of chronic kidney disease (CKD).

DATA SOURCES

A literature search was conducted in MEDLINE, EMBASE, and ClinicalTrials.gov using the keywords "daprodustat," "GSK1278863," and "hypoxia-inducible factor-prolyl hydroxylase inhibitors" from January 2010 through November 2023.

STUDY SELECTION AND DATA EXTRACTION

Literature was included if it evaluated pharmacology, pharmacokinetics, efficacy, and/or safety of daprodustat in human subjects and was reported in English. The manufacturer's product monograph was also utilized.

DATA SYNTHESIS

Daprodustat significantly increased hemoglobin levels in CKD patients on dialysis (difference 0.18 g/dL) and not on dialysis (difference 0.08 g/dL) over 52-week treatment periods compared with erythropoiesis stimulating agents (ESA) in Anemia Studies in CKD: Erythropoiesis via a Novel PHI Daprodustat (ASCEND)-D and ASCEND-ND, respectively. First occurrence of major adverse cardiovascular events (MACEs) was similar between daprodustat and ESAs in both trials.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS

Daprodustat can be used in patients with CKD on dialysis and already receiving an ESA for at least 6 weeks to further increase serum hemoglobin levels without increasing the risk of MACE. Adverse effects of daprodustat that may occur more than ESAs include headache, emesis, and thrombosis.

CONCLUSIONS

Daprodustat is a novel oral, non-iron therapy for treatment of anemia of CKD. It was Food and Drug Administration approved in 2023 in patients already receiving dialysis for at least 4 months but not in non-dialysis patients. Long-term data for safety and additional benefits are pending.

Impact of C-reactive protein on the effect of Roxadustat for the treatment of anemia in chronic kidney disease: a systematic review of randomized controlled trials

BACKGROUND

Chronic inflammation, reflected by an increased blood C-reactive protein (CRP) level, is common in patients with chronic kidney disease (CKD) and is involved in the development of renal anemia. This systematic review aims to investigate the impacts of CRP on the efficacy of hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) in the treatment of renal anemia in patients with CKD.

METHODS

We conducted a comprehensive search of electronic databases including Pubmed, Web of Science, Embase, Cochrane Library, CNKI, Wanfang, and the International Clinical Trials Registry Platform (ICTRP), from their inception to May 19, 2022. We systematically reviewed evidence from randomized controlled trials using HIF-PHIs for renal anemia treatment. The mean difference (MD) in changes in hemoglobin concentration (∆Hb) before and after treatment served as the meta-analysis outcome, utilizing a random-effects model. We compared groups with CRP levels greater than or equal to the upper limit of normal (ULN) and less than the ULN. Additionally, further analysis was conducted in the CRP ≥ ULN group comparing HIF-PHIs and erythropoiesis-stimulating agents (ESA).

RESULTS

A total of 7 studies from 6 publications were included in the analysis. In the comparison between the CRP ≥ ULN group and the CRP < ULN group, 524 patients from 4 studies were incorporated into the analysis. All patients received roxadustat as the primary intervention. The pooled results revealed no significant difference in ΔHb between patients with CRP ≥ ULN and CRP < ULN at baseline (Mean Difference: 0.00, 95% Confidence Interval: -0.32 to 0.33, P = 0.99). Moreover, within the CRP ≥ ULN group, three studies involving 1399 patients compared the efficacy of roxadustat and erythropoiesis-stimulating agents (ESAs). The results indicated no significant difference in ΔHb between patients treated with ESAs and HIF-PHIs (Mean Difference: 0.24, 95% Confidence Interval: -0.08 to 0.56, P = 0.14). In terms of medication dosage, an increase in ESA dose over time was observed across various studies, particularly evident in the CRP ≥ ULN group, while the dose of roxadustat remains constant over time and is not influenced by the baseline levels of CRP.

CONCLUSIONS

Our systematic review demonstrates that roxadustat exhibits similar efficacy across different CRP levels. Moreover, within the CRP ≥ ULN group, roxadustat can maintain efficacy comparable to ESA without the necessity for dose escalation.

TRIAL REGISTRATION

CRD42023396704.

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.

Clinical significance of massive proteinuria in primary IgA nephropathy with and without nephrotic syndrome: a single center cohort study

BACKGROUND

Both primary IgA nephropathy (IgAN) with and without nephrotic syndrome (NS) can present massive proteinuria (24-h urinary protein ≥3.5 g/d). The clinical significance of massive proteinuria may be different in the two entities and needs further research.

METHODS

Data of 1870 patients with biopsy-proven IgAN in our hospital from January 2011 to December 2022 was retrospectively reviewed. A total of 242 IgAN patients with massive proteinuria were enrolled. Patients who presented with nephrotic syndrome at renal biopsy were included in the IgAN with NS cohort (IgAN-NS). The IgAN with nephrotic-range proteinuria cohort (IgAN-NR) consisted of 1:1 matched cases from the remaining according to age, gender, estimated glomerular filtration rate (eGFR) at baseline, and follow-up time. The clinical and pathological characteristics between the two cohorts were analyzed.

RESULTS

The IgAN-NS had a significantly higher proteinuria level than the IgAN-NR (p < .001). Cluster analysis revealed that proteinuria was associated with lipids in IgAN-NS, while it was associated with inflammatory indicators in IgAN-NR. When the complete remission of proteinuria (CR) was not achieved, the Kaplan-Meier analysis showed the prognosis of IgAN-NS was significantly worse than that of IgAN-NR (p = .04). Then, our GLMM model and line chart showed that the serum albumin level of the IgAN-NR was always evidently higher than that of the IgAN-NS while the significant difference in urinary albumin/creatinine ratio between the two cohorts gradually disappeared during the short-term follow-up (1 year). Moreover, the Cox regression analysis showed that the increased serum albumin was an independent protective factor for the poor outcomes (eGFR decreased from the baseline ≥ 30% continuously or reached end-stage renal disease [ESRD]).

CONCLUSION

The IgAN-NS had poorer clinicopathologic manifestation than IgAN-NR, including severer massive proteinuria. When the CR was not achieved, the prognosis of IgAN-NS was inferior to that of the IgAN-NR.

Mutual Regulation between Redox and Hypoxia-Inducible Factors in Cardiovascular and Renal Complications of Diabetes

Oxidative stress and hypoxia-inducible factors (HIFs) have been implicated in the pathogenesis of diabetic cardiovascular and renal diseases. Reactive oxygen species (ROS) mediate physiological and pathophysiological processes, being involved in the modulation of cell signaling, differentiation, and survival, but also in cyto- and genotoxic damage. As master regulators of glycolytic metabolism and oxygen homeostasis, HIFs have been largely studied for their role in cell survival in hypoxic conditions. However, in addition to hypoxia, other stimuli can regulate HIFs stability and transcriptional activity, even in normoxic conditions. Among these, a regulatory role of ROS and their byproducts on HIFs, particularly the HIF-1α isoform, has received growing attention in recent years. On the other hand, HIF-1α and HIF-2α exert mutually antagonistic effects on oxidative damage. In diabetes, redox-mediated HIF-1α deregulation contributes to the onset and progression of cardiovascular and renal complications, and recent findings suggest that deranged HIF signaling induced by hyperglycemia and other cellular stressors associated with metabolic disorders may cause mitochondrial dysfunction, oxidative stress, and inflammation. Understanding the mechanisms of mutual regulation between HIFs and redox factors and the specific contribution of the two main isoforms of HIF-α is fundamental to identify new therapeutic targets for vascular complications of diabetes.