Safety of Dynamic Intravenous Iron Administration Strategies in Hemodialysis Patients

Roxadustat for treatment of anemia in a cancer patient with end-stage renal disease: A case report

BACKGROUND

Most cancer patients are accompanied by anemia, which will be more serious when combined with end-stage renal disease (ESRD). At present, cancer-related anemia and renal anemia treatments mainly include erythropoiesis-stimulating agents (ESAs), iron supplementation, and blood transfusion, but their effects are often poor with several safety concerns. We have used roxadustat to treat anemia in a cancer patient with ESRD and achieved a successful outcome for the first time.

CASE SUMMARY

A 64-year-old man was diagnosed with right renal cancer (clear cell renal cell carcinoma). He did not receive surgery or radiotherapy before admission. He was treated with oral soltan (sunitinib malate) on April 18, 2017. During oral chemotherapy, he had numerous complications, including anemia, hypertension, thyroid hypofunction, skin pigment loss, and renal function deterioration. At last, he progressed to ESRD and began hemodialysis treatment. We initially treated the patient with high-dose ESAs, iron supplementation, adequate dialysis, and even blood transfusion, but his anemia did not improve. Roxadustat is a newly developed drug for renal anemia treatment, but not for cancer-related anemia, let alone to treat anemia in cancer patients with ESRD. We prescribed oral roxadustat to the patient. After a period, his hemoglobin gradually increased. He did not have obvious discomfort symptoms, and his tumor did not progress significantly.

CONCLUSION

Oral roxadustat could achieve good results in treating anemia in cancer patients with ESRD.

Efficacy and safety of intravenous iron with different frequencies for renal anaemia: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

To evaluate the efficacy and safety of intravenous iron supplementation in patients with renal anaemia.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science from their inception until 17 September 2021, for randomized controlled trials (RCTs) to evaluate the efficacy and safety of intravenous iron at different frequencies. The observed efficacy indicators included transfer saturation (TSAT), serum ferritin (SF) and haemoglobin (HGB). Outcomes of interest included allergies, infections, all-cause mortality and cardiovascular events.

RESULTS AND DISCUSSION

Of the 751 eligible studies, 7 RCTs met the inclusion criteria. The RCTs showed that there were no significant differences between the low-frequency high-dose group (1-2 doses, >200 mg/dose) and the high-frequency low-dose group (4-5 doses, ≤200 mg/dose) in the increase in TSAT (WMD = 1.90; 95% CI = -2.04 to 5.84; I²  = 0%), SF (WMD = 15.70; 95% CI = -32.20 to 70.61; I²  = 0%) and HGB (WMD = -0.00; 95% CI = -0.43 to 0.42; I²  = 0%). There was also no significant difference in the occurrence of outcome events, including allergies (RR = 1.84; 95% CI = 0.95 to 3.57; I²  = 45%), infections (RR = 0.61; 95% CI = 0.20-1.86; I²  = 0%), cardiovascular events (RR = 0.88; 95% CI = 0.67-1.15; I²  = 48%) and all-cause mortality (RR = 0.74; 95% CI = 0.40-1.35; I²  = 0%).

WHAT IS NEW AND CONCLUSION

Frequencies of intravenous iron supplementation with similar doses share similar safety and efficacy in patients with renal anaemia. However, a single dose or two doses of intravenous iron are more cost-effective and patient friendly. These findings may provide evidence for the clinical application of intravenous iron supplementation for patients with renal anaemia.

Current Status of Renal Anemia Pharmacotherapy-What Can We Offer Today

Chronic kidney disease (CKD) is one of the fastest-growing major causes of death internationally. Better treatment of CKD and its complications is crucial to reverse this negative trend. Anemia is a frequent complication of CKD and is associated with unfavorable clinical outcomes. It is a devastating complication of progressive kidney disease, that negatively affects also the quality of life. The prevalence of anemia increases in parallel with CKD progression. The aim of this review is to summarize the current knowledge on therapy of renal anemia. Iron therapy, blood transfusions, and erythropoietin stimulating agents are still the mainstay of renal anemia treatment. There are several novel agents on the horizon that might provide therapeutic opportunities in CKD. The potential therapeutic options target the hepcidin–ferroportin axis, which is the master regulator of iron homeostasis, and the BMP-SMAD pathway, which regulates hepcidin expression in the liver. An inhibition of prolyl hydroxylase is a new therapeutic option becoming available for the treatment of anemia in CKD patients. This new class of drugs stimulates the synthesis of endogenous erythropoietin and increases iron availability. We also summarized the effects of prolyl hydroxylase inhibitors on iron parameters, including hepcidin, as their action on the hematological parameters. They could be of particular interest in the out-patient population with CKD and patients with ESA hyporesponsiveness. However, current knowledge is limited and still awaits clinical validation. One should be aware of the potential risks and benefits of novel, sophisticated therapies.

Controversies in optimal anemia management: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Conference

In chronic kidney disease, anemia and disordered iron homeostasis are prevalent and associated with significant adverse consequences. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) issued an anemia guideline for managing the diagnosis, evaluation, and treatment of anemia in chronic kidney disease. Since then, new data have accrued from basic research, epidemiological studies, and randomized trials that warrant a re-examination of previous recommendations. Therefore, in 2019, KDIGO decided to convene 2 Controversies Conferences to review the latest evidence, explore new and ongoing controversies, assess change implications for the current KDIGO anemia guideline, and propose a research agenda. The first conference, described here, focused mainly on iron-related issues, including the contribution of disordered iron homeostasis to the anemia of chronic kidney disease, diagnostic challenges, available and emerging iron therapies, treatment targets, and patient outcomes. The second conference will discuss issues more specifically related to erythropoiesis-stimulating agents, including epoetins, and hypoxia-inducible factor-prolyl hydroxylase inhibitors. Here we provide a concise overview of the consensus points and controversies resulting from the first conference and prioritize key questions that need to be answered by future research.

Intravenous iron therapy and the cardiovascular system: risks and benefits

Anaemia is a common complication of chronic kidney disease (CKD). In this setting, iron deficiency is frequent because of the combination of increased iron needs to sustain erythropoiesis with increased iron losses. Over the years, evidence has accumulated on the involvement of iron in influencing pulmonary vascular resistance, endothelial function, atherosclerosis progression and infection risk. For decades, iron therapy has been the mainstay of therapy for renal anaemia together with erythropoiesis-stimulating agents (ESAs). Despite its long-standing use, grey areas still surround the use of iron therapy in CKD. In particular, the right balance between either iron repletion with adequate therapy and the avoidance of iron overload and its possible negative effects is still a matter of debate. This is particularly true in patients having functional iron deficiency. The recent Proactive IV Iron Therapy in Haemodialysis Patients trial supports the use of intravenous (IV) iron therapy until a ferritin upper limit of 700 ng/mL is reached in haemodialysis patients on ESA therapy, with short dialysis vintage and minimal signs of inflammation. IV iron therapy has also been proven to be effective in the setting of heart failure (HF), where it improves exercise capacity and quality of life and possibly reduces the risk of HF hospitalizations and cardiovascular deaths. In this review we discuss the risks of functional iron deficiency and the possible benefits and risks of iron therapy for the cardiovascular system in the light of old and new evidence.

Narrative Review of Hyperferritinemia, Iron Deficiency, and the Challenges of Managing Anemia in Aboriginal and Torres Strait Islander Australians With CKD

Aboriginal and Torres Strait Islander Australians (Indigenous Australians) suffer some of the highest rates of chronic kidney disease (CKD) in the world. Among Indigenous Australians in remote areas of the Northern Territory, prevalence rates for renal replacement therapy (RRT) are up to 30 times higher than national prevalence. Anemia among patients with CKD is a common complication. Iron deficiency is one of the major causes. Iron deficiency is also one of the key causes of poor response to the mainstay of anemia therapy with erythropoiesis-stimulating agents (ESAs). Therefore, the effective management of anemia in people with CKD is largely dependent on effective identification and correction of iron deficiency. The current identification of iron deficiency in routine clinical practice is dependent on 2 surrogate markers of iron status: serum ferritin concentration and transferrin saturation (TSAT). However, questions exist regarding the use of serum ferritin concentration in people with CKD because it is an acute-phase reactant that can be raised in the context of acute and chronic inflammation. Serum ferritin concentration among Indigenous Australians receiving RRT is often markedly elevated and falls outside reference ranges within most national and international guidelines for iron therapy for people with CKD. This review explores published data on the challenges of managing anemia in Indigenous people with CKD and the need for future research on the efficacy and safety of treatment of anemia of CKD in patients with high ferritin and evidence iron deficiency.

Factors associated with hepcidin-25 levels in maintenance hemodialysis patients

This study aimed to investigate the factors that are independently associated with hepcidin-25 and its relationship with doses of erythropoiesis-stimulating agents (ESAs) and intravenous iron in stable maintenance hemodialysis patients (smHD) stratified by ESAs administration. In 103 adult smHD (ESAs therapy (N = 64) and ESAs-free (N = 39)), median values of biologically active hepcidin-25 (chemiluminescent direct ELISA assay) and ferritin levels were significantly higher whereas red blood cell count, hemoglobin, and hematocrit values were lower in ESAs therapy compared to ESAs-free group (P < .001, for all). Our results suggest that ESAs-independent smHD exhibit supposedly normal hepcidin-25 levels and preserved iron homeostasis, with a lower degree of anemia. The results of our multivariable model indicate that hepcidin-25 levels are independently and positively associated with iron stores and inflammation, and inversely with active erythropoiesis, regardless of ESAs administration. Maintenance ESAs and the intravenous iron dose were not related to hepcidin-25 levels.

Improving the safety of intravenous iron treatments for patients with chronic kidney disease

Introduction: Iron-deficiency anemia in chronic kidney disease (CKD) is common and has prognostic, financial, and quality of life implications. Intravenous (IV) iron is a key intervention for optimal management, however, ongoing safety concerns exist. Area covered: The potential side effects associated with IV iron use are addressed as we review the most recent studies. Hypersensitivity reactions and true anaphylaxis are indeed rare with a greater understanding of the nature of labile iron and 'Fishbane' reactions. Hypophosphatemia appears commoner with certain IV iron preparations, however its significance in CKD requires exploration. The long-standing questions regarding oxidative stress and the potential susceptibility to infections and worsening cardiovascular morbidity are discussed. Iron overload secondary to repeat IV iron infusions is plausible, however, a number of guidelines limit and strictly guide prescription. Expert opinion: The past decade has improved our understanding of IV iron administration safety in patients with CKD. Third generation IV iron compounds have minimized hypersensitivity reactions while allowing high doses to be administered safely and rapidly in non-dialysis-dependent CKD patients. However, differences in safety profiles such as hypophosphatemia require further study and therapy should be tailored to the individual. Clinicians should feel confident in using IV iron therapy.

Replicating Randomized Trial Results with Observational Data Using the Parametric g-Formula: An Application to Intravenous Iron Treatment in Hemodialysis Patients

BACKGROUND

Reproducibility of clinical and epidemiologic research is important to generalize findings and has increasingly been scrutinized. A recently published randomized trial, PIVOTAL, evaluated high vs low intravenous iron dosing strategies to manage anemia in hemodialysis patients in the UK. Our objective was to assess the reproducibility of the PIVOTAL trial findings using data from a well-established cohort study, the Dialysis Outcomes and Practice Patterns Study (DOPPS).

METHODS

To overcome the absence of randomization in the DOPPS, we applied the parametric g-formula, an extension of standardization to longitudinal data. We estimated the effect of a proactive high-dose vs reactive low-dose iron supplementation strategy on all-cause mortality (primary outcome), hemoglobin, two measures of iron concentration (ferritin and TSAT), and erythropoiesis-stimulating agent dose over 12 months of follow-up in 6325 DOPPS patients.

RESULTS

Comparing high- vs low-iron dose strategies, the 1-year mortality risk difference was 0.020 (95% CI: 0.008, 0.031) and risk ratio was 1.20 (95% CI: 1.07, 1.33), compared with null 1-year findings in the PIVOTAL trial. Differences in secondary outcomes were directionally consistent but of lesser magnitude than in the PIVOTAL trial.

CONCLUSION

Our findings are somewhat consistent with the recent PIVOTAL trial, with discrepancies potentially attributable to model misspecification and differences between the two study populations. In addition to the importance of our results to nephrologists and hence hemodialysis patients, our analysis illustrates the utility of the parametric g-formula for generalizing results and comparing complex and dynamic treatment strategies using observational data.

Erythropoietin Resistance in Patients with Chronic Kidney Disease: Current Perspectives

Anemia is a frequent complication of chronic kidney disease, and its primary cause is erythropoietin deficiency. After diagnosis, treatment begins with administration of an erythropoiesis-stimulating agent (ESA). However, some patients present with resistance to ESA, which needs to be reversed, as it can increase the risk of death in patients with kidney disease. Therefore, we provide a discussion of the current literature regarding the factors that can modify the response to this class of drugs and the strategies that can be considered to optimize the benefits of treating anemia.

Potential hazards of recent trends in liberal iron use for renal anemia

A randomized controlled trial,the Proactive IV Iron Therapy in Haemodialysis Patients (PIVOTAL), has recently shown that a high-dose (‘proactive’) intravenous iron regimen was superior to a low-dose (‘reactive’) regimen for hemodialysis patient outcomes and overall safety. However, even in the low-dose group, a substantial amount of iron was administered to maintain serum ferritin >200 ng/mL. This type of comparison may have strongly affected the safety results. Iron has two opposite effects on erythropoiesis: it activates erythroid differentiation directly by supplying iron but inhibits it indirectly by stimulating hepcidin and enhancing oxidative stress. Hepcidin plays an essential role not only in iron homeostasis and the anemia of chronic kidney disease, but also in its complications such as atherosclerosis and infection. Its main stimulation by iron—and to a lesser degree by inflammation—should urge clinicians to avoid prescribing excessive amounts of iron. Furthermore, as serum ferritin is closely correlated with serum hepcidin and iron storage, it would seem preferable to rely mainly on serum ferritin to adjust iron administration, defining an upper limit for risk reduction. Based on our estimations, the optimal range of serum ferritin is ∼50–150 ng/mL, which is precisely within the boundaries of iron management in Japan. Considering the contrasting ranges of target ferritin levels between end-stage renal disease patients in Japan and the rest of the world, the optimal range proposed by us will probably be considered as unacceptable by nephrologists abroad. Only well-balanced, randomized controlled trials with both erythropoiesis-stimulating agents and iron will allow us to settle this controversy.

Intravenous Iron Dosing and Infection Risk in Patients on Hemodialysis: A Prespecified Secondary Analysis of the PIVOTAL Trial

BACKGROUND

Experimental and observational studies have raised concerns that giving intravenous (IV) iron to patients, such as individuals receiving maintenance hemodialysis, might increase the risk of infections. The Proactive IV Iron Therapy in Haemodialysis Patients (PIVOTAL) trial randomized 2141 patients undergoing maintenance hemodialysis for ESKD to a high-dose or a low-dose IV iron regimen, with a primary composite outcome of all-cause death, heart attack, stroke, or hospitalization for heart failure. Comparison of infection rates between the two groups was a prespecified secondary analysis.

METHODS

Secondary end points included any infection, hospitalization for infection, and death from infection; we calculated cumulative event rates for these end points. We also interrogated the interaction between iron dose and vascular access (fistula versus catheter).

RESULTS

We found no significant difference between the high-dose IV iron group compared with the lose-dose group in event rates for all infections (46.5% versus 45.5%, respectively, which represented incidences of 63.3 versus 69.4 per 100 patient years, respectively); rates of hospitalization for infection (29.6% versus 29.3%, respectively) also did not differ. We did find a significant association between risk of a first cardiovascular event and any infection in the previous 30 days. Compared with patients undergoing dialysis with an arteriovenous fistula, those doing so via a catheter had a higher incidence of having any infection, hospitalization for infection, or fatal infection, but IV iron dosing had no effect on these outcomes.

CONCLUSIONS

The high-dose and low-dose IV iron groups exhibited identical infection rates. Risk of a first cardiovascular event strongly associated with a recent infection.

Iron Administration, Infection, and Anemia Management in CKD: Untangling the Effects of Intravenous Iron Therapy on Immunity and Infection Risk

Patients with chronic kidney disease (CKD) are at increased risk for infection, attributable to immune dysfunction, increased exposure to infectious agents, loss of cutaneous barriers, comorbid conditions, and treatment-related factors (eg, hemodialysis and immunosuppressant therapy). Because iron plays a vital role in pathogen reproduction and host immunity, it is biologically plausible that intravenous iron therapy and/or iron deficiency influence infection risk in CKD. Available data from preclinical experiments, observational studies, and randomized controlled trials are summarized to explore the interplay between intravenous iron and infection risk among patients with CKD, particularly those receiving maintenance hemodialysis. The current evidence base, including data from a recent randomized controlled trial, suggests that proactive judicious use of intravenous iron (in a manner that minimizes the accumulation of non-transferrin-bound iron) beneficially replaces iron stores while avoiding a clinically relevant effect on infection risk. In the absence of an urgent clinical need, intravenous iron therapy should be avoided in patients with active infection. Although serum ferritin concentration and transferrin saturation can help guide clinical decision making about intravenous iron therapy, definition of an optimal iron status and its precise determination in individual patients remain clinically challenging in CKD and warrant additional study.

Treatment of Renal Anemia with Roxadustat: Advantages and Achievement

Background

Although renal anemia has attracted widespread attention, a large proportion of chronic kidney disease (CKD) patients with anemia still do not meet the hemoglobin (Hb) targets. The discovery of prolyl hydroxylase domain (PHD) enzymes as regulators of hypoxia-inducible factor (HIF)-dependent erythropoiesis has led to the development of novel therapeutic agents for renal anemia. Roxadustat, the first small-molecule HIF-PHD inhibitor, has completed the phase 3 trials. There are currently more than 15 phase 3 clinical trials worldwide assessing the efficacy and safety of roxadustat in CKD patients with anemia. This review will summarize recent findings of roxadustat in the treatment of renal anemia.

Summary

Although the administration of erythropoiesis-stimulating agents (ESAs) and iron supplementation are a well-established and highly effective therapeutic approach for renal anemia, there are several safety concerns. Current findings from phase 2 and 3 trials suggest that roxadustat is clinically effective and well tolerated. On the one hand, roxadustat could increase endogenous erythropoietin (EPO) levels within or near physiological range in a titratable manner by inducing HIF pathway activation transiently. On the other hand, roxadustat also improves iron metabolism by decreasing serum hepcidin and increasing intestinal iron absorption, which is beneficial to functional iron deficiency and absolute iron deficiency. More importantly, the erythropoietic response of roxadustat is independent of baseline inflammatory state of CKD patients. Thus, the discovery of roxadustat will revolutionize the treatment strategy for renal anemia.

Key Messages

Roxadustat is an emerging and promising therapeutic approach against anemia in CKD patients, which differs from those of conventional ESAs. Roxadustat corrects anemia of CKD patients through multiple pathways, beyond elevating EPO levels within physiological range, and also by handling iron metabolism (particularly decreasing the hepcidin levels). Furthermore, the Hb response of roxadustat is independent of the inflammatory microenvironment.

Risk of iron overload with chronic indiscriminate use of intravenous iron products in ESRD and IBD populations

The routine use of recombinant erythropoiesis-stimulating agents (ESA) over the past three decades has enabled the partial correction of anaemia in most patients with end-stage renal disease (ESRD). Since ESA use frequently leads to iron deficiency, almost all ESA-treated haemodialysis patients worldwide receive intravenous iron (IV) to ensure sufficient available iron during ESA therapy. Patients with inflammatory bowel disease (IBD) are also often treated with IV iron preparations, as anaemia is common in IBD. Over the past few years, liver magnetic resonance imaging (MRI) has become the gold standard method for non-invasive diagnosis and follow-up of iron overload diseases. Studies using MRI to quantify liver iron concentration in ESRD have shown a link between high infused iron dose and risk of haemosiderosis in dialysis patients. In September 2017, the Pharmacovigilance Committee (PRAC) of the European Medicines Agency (EMA) considered convergent publications over the last few years on iatrogenic haemosiderosis in dialysis patients and requested that companies holding marketing authorization for iron products should investigate the risk of iron overload, particularly in patients with end-stage renal disease on dialysis and, by analogy, patients with IBD. We present a narrative review of data supporting the views and decision of the EMA, and then give our expert opinion on this controversial field of anaemia therapeutics.

Long-Term Risks of Intravenous Iron in End-Stage Renal Disease Patients

Patients with end-stage renal disease on dialysis commonly receive intravenous iron to treat anemia along with erythropoiesis-stimulating agents. While studies of intravenous iron have demonstrated efficacy in raising hemoglobin, the quantity of administered intravenous iron has raised concerns about iron overload leading to long-term toxicities. The goal of this review is to understand recent trends in intravenous iron use, potential mechanisms of iron toxicity, and to evaluate the available evidence in the literature for potential long-term cardiovascular and infectious complications. We include findings from the recently published landmark clinical trial of intravenous iron for patients receiving hemodialysis to contextualize treatment recommendations.