Hypophosphataemia after treatment of iron deficiency with intravenous ferric carboxymaltose or iron isomaltoside-a systematic review and meta-analysis

Iron and bones: effects of iron overload, deficiency and anemia treatments on bone

Iron is a vital trace element and exerts opposing effects on bone in both iron overload and iron deficiency situations. Remarkably, iron supplementation through intravenous infusion in patients with iron deficiency can also have detrimental effects on bone in special cases. The diverse mechanisms underlying these effects and their manifestations contribute to the complexity of this relationship. Iron overload impacts both bone resorption and formation, accelerating bone resorption while reducing bone formation. These effects primarily result from the direct action of reactive oxygen species (ROS), which influence the proliferation, differentiation, and activity of both osteoclasts and osteoblasts differently. This imbalance favors osteoclasts and inhibits the osteoblasts. Simultaneously, multiple pathways, including bone morphogenic proteins, RANK ligand, and others, contribute to these actions, leading to a reduction in bone mass and an increased susceptibility to fractures. In contrast, iron deficiency induces low bone turnover due to energy and co-factor deficiency, both of which require iron. Anemia increases the risk of fractures in both men and women. This effect occurs at various levels, reducing muscular performance and, on the bone-specific level, decreasing bone mineral density. Crucially, anemia increases the synthesis of the phosphaturic hormone iFGF23, which is subsequently inactivated by cleavage under physiological conditions. Thus, iFGF23 levels and phosphate excretion are not increased. However, in specific cases where anemia has to be managed with intravenous iron treatment, constituents-particularly maltoses-of the iron infusion suppress the cleavage of iFGF23. As a result, patients can experience severe phosphate wasting and, consequently, hypophosphatemic osteomalacia. This condition is often overlooked in clinical practice and is often caused by ferric carboxymaltose. Ending iron infusions or changing the agent, along with phosphate and vitamin D supplementation, can be effective in addressing this issue.

Expert consensus guidelines: Intravenous iron uses, formulations, administration, and management of reactions

Intravenous iron has become an essential component for the treatment of iron deficiency and iron deficiency anemia. Individuals administering Intravenous iron should have knowledge in intravenous iron administration, including a pre-infusion assessment to evaluate infusion reaction risks, pre- and post-infusion monitoring, identification of and management of infusion reactions, accurate documentation of these reactions, laboratory monitoring and recognition and management of treatment-emergent hypophosphatemia. This comprehensive consensus provides step-by-step guidance and tools for practitioners to promote safe delivery of intravenous iron, recognition, and management of infusion reactions and treatment-emergent hypophosphatemia.

Screening and treatment of iron deficiency anemia in pregnancy: A review and appraisal of current international guidelines

Iron deficiency anemia (IDA) in pregnancy is a common diagnosis that is associated with adverse obstetric and neonatal outcomes. There remains uncertainty regarding how best to screen for, prevent, and treat established IDA in pregnancy. There is no consensus on the benefits of routine iron supplementation in pregnancy, with concerns regarding potential harmful effects of routine iron supplementation in women who are iron replete. Fourteen international guidelines were selected and appraised and compared by a multidisciplinary team. The AGREE II GRS tool was used. Each reviewer independently made their own assessment, and the scores from 1 to 7 were also collated and averaged for an overall score incorporating seven domains: process of development, clarity of presentation, completeness of reporting, clinical validity, and overall quality. The reviewers' scores were also individually compared according to discipline. The mean score across all the guidelines was 4.4 (range 3.5-6.5). Only half of the guidelines recommend routine iron in pregnancy. In terms of screening recommendations, five guidelines recommend screening with ferritin in addition to a full blood count in pregnancy, two recommend selective screening with ferritin for at risk groups only, and one guideline suggests using ferritin where feasible. Although many of the guidelines recommend similar doses of oral elemental iron of 100-200 mg daily for the treatment of established IDA in pregnancy, two recommend twice or three times daily dosing. Only five guidelines give hemoglobin rises to expect within specific timeframes. There remains a need to clarify the optimal screening method, dosing regimen, timing, and route of iron supplementation in pregnancy. Robust randomized controlled data are needed to guide appropriate prevention and management.

Intravenous iron-induced hypophosphatemia and kidney stone disease

Patients with Crohn's disease are at increased risk for symptomatic nephrolithiasis. Stones in these patients are most commonly composed of calcium oxalate monohydrate or mixed calcium-oxalate and calcium-phosphate. Precipitation of both minerals depends on urinary pH, calcium, phosphate and oxalate excretion. The present manuscript reports on two patients with Crohn's disease and bowel resection, in whom the onset of symptomatic urolithiasis occurred after repeated infusions of ferric carboxymaltose - a drug, which is known to cause hyperphosphaturia. The present study shows that ferric carboxymaltose-induced hyperphosphaturia can be associated with kidney stone formation and symptomatic urolithiasis, especially in patients treated with calcitriol. Calcitriol has been shown to mitigate ferric carboxymaltose-induced secondary hyperparathyroidism and hyperphosphaturia, but is known to increase urinary calcium excretion. Chemical analysis of recovered stones revealed that they were mixed calcium oxalate and phosphate stones. Ring-like deposition of iron detected by spatially resolved elemental analysis using laser ablation-inductively coupled plasma mass spectrometry, showed that the stones also contained iron. Based on our findings, we propose that patients with inflammatory bowel disease requiring intravenous iron therapy should be carefully monitored for the development of hypophosphatemia and urolithiasis. If hypophosphatemia occurs in such patients, calcitriol should be used with caution.

Cardiac Arrest During a Ferric Derisomaltose Infusion Followed by Complete Heart Block: A Case Report

Introduction

Ferric derisomaltose is the newest available parenteral iron formulation. Studies have demonstrated a good safety profile with improved tolerability compared to alternative parenteral iron formulations. To date there have been no reported acute, life-threatening cardiac events associated with ferric derisomaltose.

Case Report

An 86-year-old male who had previously tolerated routine iron infusions received a first dose of ferric derisomaltose at an outpatient infusion clinic. Six minutes into the infusion the patient became unresponsive with no palpable pulse. Return of spontaneous circulation was achieved after two minutes of chest compressions. Electrocardiogram showed complete heart block requiring transcutaneous pacing and vasopressor administration. The patient was transferred to the emergency department for stabilization and then admitted to the cardiac intensive care unit. During admission, the patient received a dual-chamber, permanent pacemaker without complication and was ultimately discharged.

Conclusion

It may be reasonable to consider parenteral iron as a toxicological etiology for patients presenting with complete heart block temporally associated with parenteral iron administration, particularly in patients with underlying conduction abnormalities.

Regulation of FGF23 Production in Osteocytes

PURPOSE OF REVIEW

FGF23 is a bone-derived hormone working to reduce serum phosphate level. This review focuses on recent findings regarding regulatory mechanisms of FGF23 expression in osteocytes, FGF23 levels, and activities.

RECENT FINDINGS

Circulatory FGF23 levels reflecting FGF23 biological activities can be regulated by both FGF23 expression and posttranslational modification of FGF23 protein. O-linked glycosylation and phosphorylation of FGF23 protein as well as enzymes that can cleave FGF23 protein are involved in the posttranslational modification. However, precise mechanisms of FGF23 protein processing are not clear. Several extracellular factors have been shown to affect FGF23 levels in kidney injuries. Contribution of these factors may be different depending on the causes and stages of kidney injury. FGF23 activities are regulated by complex mechanisms involving transcriptional and posttranslational modulations. There still remain several questions regarding the regulatory mechanisms of FGF23 expression and FGF23 processing.

Acquired disorders of phosphaturia: Beyond tumor-induced osteomalacia

Phosphate is an integral part of human cellular structure and function. Though most recognised disorders of phosphaturia are genetic in origin, phosphate loss due to acquired conditions is commonly encountered in clinical practice. Acquired hypophosphatemia is most commonly due to renal phosphate wasting and can produce significant morbidity. It also heralds future kidney damage, and continued exposure can lead to progressive kidney injury and potentially renal failure. These conditions are a diverse group of disorders with common shared mechanisms causing loss of phosphate in the urine. Renal phosphate loss can occur as an isolated entity or as a part of generalised proximal tubular dysfunction, i.e., Fanconi's syndrome. An insight into the pathophysiological mechanisms of acquired phosphaturia can help clinicians monitor their patients better and avoid potential harms.

The differential effect of modern intravenous iron on fibroblast growth factor 23 and phosphate in non-dialysis dependent CKD - the exploratory randomized controlled double-blind ExplorIRON-CKD study

BACKGROUND

Intravenous iron is commonly used in patients with non-dialysis-dependent chronic kidney disease (CKD). Modern intravenous iron compounds (e.g. ferric derisomaltose (FDI), ferric carboxymaltose (FCM)) are increasingly utilized with similar efficacy. A differential effect in terms of hypophosphatemia has been noted following administration of FCM, which may be related to fibroblast growth factor 23 (FGF23). This study was designed to examine the comparative effects of FDI and FCM on FGF23, phosphate and other markers of bone turnover.

METHODS

The single-center double-blind randomized controlled trial "Iron and Phosphaturia - ExplorIRON-CKD" primarily assessed the effects of FCM and FDI on intact FGF23 and phosphate, whilst also studying the impact on vitamin D, parathyroid hormone and phosphaturia. Bone markers including alkaline phosphatase, bone-specific alkaline phosphatase, procollagen type 1 N-terminal propeptide and carboxy-terminal collagen cross-linked telopeptide were monitored. Non-dialysis-dependent CKD patients (stage 3a-5) with iron deficiency with/without anemia (serum ferritin < 200 µg/L or transferrin saturation = 20% and serum ferritin 200-299 µg/L) were randomized to receive FDI or FCM in a 1:1 ratio. At baseline 1000 mg of intravenous iron was administered followed by 500-1000 mg at 1 month to achieve replenishment. Measurements were performed at baseline, 1-2 days following iron administration, 2 weeks, 1 month (second iron administration), 1-2 days following second administration, 2 months and 3 months following initial infusion.

RESULTS

Twenty-six patients participated in the trial; 14 randomized to FDI and 12 to FCM. Intact FGF23 increased following administration of iron, and the increase was significantly higher with FCM compared to FDI (Baseline to 1-2 days following 1st administration: FDI: 3.0 (IQR: - 15.1 - 13.8) % vs. FCM: 146.1 (IQR: 108.1-203.1) %; p < 0.001 and Baseline to 1-2 days following 2nd administration: FDI: 3.2 (IQR: - 3.5 - 25.4) % vs. FCM: 235.1 (138.5-434.6) %; p = 0.001). Phosphate levels decreased in the FCM group, causing a significant difference versus FDI 2 weeks following administration of the first dose. A significantly greater decrease in 1,25 (OH)2 Vitamin D was noted with FCM. Several markers of bone turnover significantly changed following administration of FCM but not FDI.

CONCLUSIONS

The study suggests a differential effect on FGF23 following administration of FCM compared to FDI in non-dialysis-dependent CKD patients, similar to other patient groups. This may lead to changes consistent with hypovitaminosis D and alterations in bone turnover with potential clinical consequences. Further definitive studies are required to understand these differences of intravenous iron compounds.

TRIAL REGISTRATION

European Union Drug Regulating Authorities Clinical Trials Database (EudraCT) number: 2019-004370-26 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-004370-26/GB ) (First date of trial registration: 03/12/2019).

Concurrent Denosumab and Parenteral Iron Therapy Precipitating Severe Hypocalcemia and Hypophosphatemia

Denosumab-induced hypocalcemia and iron infusion-related hypophosphatemia are both well described. We describe a case of severe hypocalcemia and hypophosphatemia following sequential denosumab and parenteral iron administration. This resulted in respiratory failure due to muscle weakness and cardiac arrhythmia, requiring noninvasive ventilation and urgent intravenous electrolyte replacement. This case highlights the severe dysregulation in calcium and phosphate homeostasis that can occur with denosumab and iron infusions when administered in quick succession. Given that these drugs are among the most common therapies prescribed across a range of specialties, we hope to alert clinicians to this potential serious drug-drug interaction and suggest strategies for monitoring and management of the electrolyte derangement.

Is It Time to Alter the Standard of Care for Iron Deficiency/Iron Deficiency Anemia in Reproductive-Age Women?

Two billion people worldwide suffer from anemia, with reproductive-age women being disproportionately affected. Iron plays a crucial role in cellular function and impacts cognition, physical function, and quality of life. Iron deficiency (ID) and iron deficiency anemia (IDA) are associated with adverse effects on pregnancy and fetal development. Oral iron supplementation has been the standard treatment for decades, often producing sub-optimal outcomes. Many babies are still being born with ID and suffer adverse sequelae due to inadequate iron levels in the mothers. Is it time to consider a broad scale-up of parenteral iron as a new standard of care?

Intravenous iron: an update

Iron deficiency is the most common nutritional deficiency worldwide, with significant adverse health consequences in the presence or absence of anaemia. Total dose intravenous iron replacement is recommended for replacement of iron in patients with severe iron deficiency, especially in the presence of anaemia, intolerance or inefficacy following oral iron, or states of inflammation where upregulation of hepcidin may impair gastrointestinal absorption of iron. Currently, available intravenous iron formulations have been demonstrated to have an excellent overall safety profile, but potential adverse effects, including skin staining, infusion-related reactions and hypophosphataemia, have been described. Knowledge of differences in administration and safety profiles of currently available iron formulations will allow appropriate prescription, counselling, as well as recognition and management of adverse events in patients requiring intravenous iron.

Cost-utility analysis of ferric derisomaltose versus ferric carboxymaltose in patients with inflammatory bowel disease and iron deficiency anemia in England

AIMS

Anemia is the most common extraintestinal complication of inflammatory bowel disease (IBD), with approximately half of cases caused by iron deficiency (ID). Intravenous iron is the preferred ID anemia (IDA) treatment where oral iron is contraindicated, ineffective or not tolerated, or where ID correction is urgent. The objective was to evaluate the cost-utility of ferric derisomaltose (FDI) versus ferric carboxymaltose (FCM) in patients with IBD and IDA in England, in whom IV iron treatment is preferred.

MATERIALS AND METHODS

A patient-level simulation model was developed, capturing quality of life (QoL) differences based on SF-36v2 data from the PHOSPHARE-IBD randomized controlled trial, monitoring and incidence of post-infusion hypophosphatemia, and number of iron infusions required. Analyses were conducted over a five-year time horizon from the Department of Health and Social Care (DHSC) perspective, with healthcare provider and societal perspectives adopted in separate analyses. Future costs and effects were discounted at 3.5% per annum and one-way and probabilistic sensitivity analyses were performed.

RESULTS

FDI increased quality-adjusted life expectancy by 0.075 QALYs versus FCM from 2.57 QALYs to 2.65 QALYs per patient. Patients receiving FDI required 1.63 fewer iron infusions over the five-year time horizon, driving infusion-related cost savings of GBP 496 per patient (GBP 2,188 versus GBP 1,692) from the DHSC perspective. Costs of monitoring and treating hypophosphatemia after FCM were GBP 226, yielding total savings of GBP 722 per patient (GBP 2,414 versus GBP 1,692) over the five-year time horizon. FDI also led to reduced costs versus FCM in the societal and provider analyses and was therefore the dominant intervention across all three perspectives.

LIMITATIONS

The analysis did not capture patient adherence, hypophosphatemic osteomalacia, or fractures.

CONCLUSIONS

Results showed that FDI improved patient QoL and reduced direct healthcare expenditure versus FCM in patients with IBD and IDA in England.

IV iron formulations and use in adults

Intravenous iron has become a major component of the therapeutic armamentarium for iron deficiency and iron deficiency anemia. The earliest formulations were associated with unacceptable toxicity. Newer formulations, with complex carbohydrate cores that bind elemental iron more tightly, allow the administration of full therapeutic doses in 15 to 60 minutes. Nonetheless, a folklore of danger, fueled by earlier formulations no longer available, continues to foment caution. Complement-mediated minor infusion reactions, referred to as complement activation-related pseudo-allergy, resolve without therapy. Inappropriate intervention with vasopressors and H1 blockers converts these minor reactions into hemodynamically significant adverse events. Four new formulations, low-molecular-weight iron dextran, ferumoxytol, ferric carboxymaltose, and ferric derisomaltose, all approved for the treatment of iron deficiency in a host of conditions, are now widely used with an excellent safety profile. Herein, the administration, safety, indications, and management of infusion reactions are discussed. Treatment-emergent hypophosphatemia, a newly recognized side effect for some formulations, is also reviewed. Based on the preponderance of published evidence, intravenous iron should be moved up-front for the treatment of iron deficiency and iron deficiency anemia in those conditions in which oral iron is suboptimal.

Hypophosphatemia related to intravenous iron therapy with ferric carboxymaltose: A case series

OBJECTIVES

This case series would like to highlight hypophosphatemia related to ferric carboxymaltose and its adverse clinical consequences.

BACKGROUND

Intravenous iron supplementation is a good alternative to oral iron replacement in iron deficiency anaemia due to its ability to correct iron deficit with minimal infusions without incurring the gastrointestinal side effects of oral iron replacement. Ferric carboxymaltose is one common formula for intravenous iron supplementation. However, an increasingly recognised adverse side-effect of intravenous ferric carboxymaltose is hypophosphatemia. There has been increasing reports and studies highlighting hypophosphatemia related to intra-venous iron therapy. Though initially thought to be transient and asymptomatic, recent studies have shown that persistent hypophosphatemia in iron therapy can result in debilitating disease including myopathy, fractures and osteomalacia.

METHODS

A retrospective analysis of all patients who had ferric carboxymaltose was performed.

RESULTS

We highlight 3 cases where hyposphatemia affected the clinical outcomes.

CONCLUSION

With the increased use of IV iron it is important to be aware of the high potential for hypophosphatemia secondary to ferric carboxymaltose.

Patient reported outcome measures and cardiovascular outcomes following high dose modern intravenous iron in non-dialysis dependent chronic kidney disease: secondary analysis of ExplorIRON-CKD

Intravenous iron is commonly used to treat iron deficiency anemia in non-dialysis chronic kidney disease (ND-CKD). There is a paucity of information on the potential impact of intravenous iron on patient reported outcome measures, functional status and markers of cardiovascular health. As part of the secondary analysis of this double-blind exploratory randomized controlled trial focusing on patients with iron deficiency (+ /- anemia) and ND-CKD (serum ferritin < 200 µg/L or transferrin saturation ≤ 20% and serum ferritin 200-299 µg/L; CKD stages: 3a-5), 26 patients were randomized in a 1:1 ratio to receive ferric derisomaltose or ferric carboxymaltose. Participants received 1000 mg at baseline and 500-1000 mg at one month to achieve iron repletion. Quality of life and fatigue status were assessed using the Short-Form (36) questionnaire and the fatigue severity scale. Functional status was evaluated using the Duke Activity Status Index and the 1-min-sit-to-stand test. Cardiac markers such as NT-proBNP, Troponin T and pulse wave velocity were monitored. Intravenous iron was associated with similar improvements in most domains of the Short-Form (36) questionnaire, fatigue status, and 1-min-sit-to-stand ability increased significantly by the end of the trial in both groups (p < 0.001). Markers of cardiac function remained stable, with no arterial stiffness impact. Longer term studies are required to further evaluate the impact of intravenous iron on quality of life and cardiac safety in patients with ND-CKD.

Incidence and predictors of hypophosphataemia after ferric carboxymaltose use-A 3-year experience from a single institution in Singapore

Ferric carboxymaltose (FCM) administration helps reduce transfusion requirements in the perioperative situation, which improves patient outcomes and reduces healthcare costs. However, there is increasing evidence of hypophosphataemia after FCM use. We aim to determine the incidence of hypophosphataemia after FCM administration and elucidate potential biochemical factors associated with the development of subsequent hypophosphataemia. A retrospective review of anonymised data of all FCM administrations in a single institution was conducted from August 2018 to August 2021. Each unique FCM dose administered was examined to assess its effect on Hb and serum phosphate levels within the subsequent 28 days from each FCM administration. Phosphate levels were repeatedly measured within the 28-day interval and the lowest phosphate level within that period was determined. Patients' serum phosphate levels within 28 days of FCM administration were compared against normal serum phosphate levels within 2 weeks before FCM administration. The odds ratios of various pre-FCM serum markers were calculated to elucidate potential biochemical predictors of post-FCM hypophosphataemia. In 3 years, a total of 1296 doses of FCM were administered to 1069 patients. The mean improvement in Hb was 2.45 g/dL (SD = 1.94) within 28 days of FCM administration, with the mean time taken to peak Hb levels being 6.3 days (SD = 8.63), which is earlier than expected, but was observed in this study and hence reported. The incidence of hypophosphataemia <0.8 mmol/L was 22.7% (n = 186), and <0.4 mmol/L was 1.6% (n = 9). This figure is lower than the numbers reported in previously published meta-analyses given that routine checks of serum phosphate levels were not conducted initially and hence could possibly be higher. The odds of developing hypophosphataemia (<0.8 mmol/L) were 27.7 (CI: 17.3-44.2, p < 0.0001) if baseline serum phosphate was less than 1 mmol/L. The odds of developing hypophosphataemia (<0.8 mmol/L) were 1.3 (CI: 1.08-1.59, p < 0.01) if the change in Hb levels observed after FCM administration were more than 4 g/dL. Hypophosphataemia after FCM administration is significant and FCM should be used by clinicians with caution.

[Hypophosphatemia after injectable iron treatments in adults: Comparison between ferric carboxymaltose and iron sucrose]

Hypophosphatemia is a recognized side effect of treatment of iron deficiency anemias with injectable iron. We analyzed 35 clinical trials that used ferric carboxymaltose (FCM) or iron sucrose (IS). Hypophosphatemia prevalence ranged from 0 to 91.7%. FCM-induced a significant (P<0.001) greater hypophosphatemia prevalence and phosphatemia decrease than IS (52.0% [95% CI: 42.2-61.8%] vs. 7.7% [95% CI: -2.8 to 18.2%] and -1.12mmol/L [95% CI: -1.36 to -0.89mmol/L] vs. -0.13mmol/L [95% CI: -0.59 to 0.32mmol/L]). FCM-induced hypophosphatemia was dose-dependent. The nadir of hypophosphatemia was reached in almost all studies after 7 and 14days. Hypophosphatemia persisted at the end of the study in 53.8% of the reported studies that used FCM and lasted up to 6months. FCM-induced an increase in intact circulating fibroblast growth factor 23 and in renal phosphorus excretion while serum 1-25 dihydroxyvitamin D was decreased. Risk factors for hypophosphatemia after FCM therapy were low basal circulating phosphate or ferritin, low body weight, high glomerular filtration rate, serum parathyroid hormone or hemoglobin and age, whereas renal insufficiency was associated with a lower risk. In conclusion, hypophosphatemia is common after treatment with injectable iron, FCM being associated with a higher risk than IS and with disorders of phosphocalcium metabolism. Monitoring of blood phosphate and 1-25 dihydroxyvitamin D could be considered during FCM therapy.

Treatment Options for Anemia in Kidney Transplant Patients: A Review

Anemia is common after kidney transplantation. The etiology may be multifactorial, such as causes of anemia in the general population and causes that are unique to the kidney transplant setting. Posttransplant anemia, particularly when severe, may be associated with adverse effects such as graft failure, mortality, and a decline in kidney function. After careful investigation, that is, having excluded or treated reversible causes of anemia, treatment of anemia in patients with a kidney transplant is based on iron supplementation or erythropoiesis-stimulating agents (ESA), although there are no specific guidelines on anemia management in this patient population. Iron therapy is often needed, but optimal and safe iron-deficiency management strategies remain to be defined. Evidence suggests that ESAs are safe and potentially associated with favorable outcomes. Better graft function has been reported with ESA use targeting hemoglobin levels higher than those recommended in the general population with chronic kidney disease and with no apparent increased risk of cardiovascular events. These results require further investigation. Data on the use of hypoxia-inducible factor inhibitors are limited. Prevention and treatment of anemia in kidney transplantation can improve patients' quality of life, life expectancy, allograft function, and survival.

Interaction between ferric carboxymaltose and denosumab causing severe hypocalcaemia and hypophosphataemia in a patient without chronic kidney disease

Coadministration of ferric carboxymaltose and denosumab may cause hypocalcaemia and hypophosphataemia; however, this interaction is not well-described in the literature and has typically been described in patients with chronic kidney disease (CKD). We present a case of this interaction in a patient without preexisting CKD. We suggest the use of alternative iron preparations and an interval of at least 4 weeks between administrations.

Methodology and Baseline Data of a Comparative Exploratory Double-Blinded Randomized Study of Intravenous Iron on Fibroblast Growth Factor 23 and Phosphate in Chronic Kidney Disease

Modern intravenous iron compounds (e.g., ferric carboxymaltose [FCM] and ferric derisomaltose [FDI]) are utilized in the treatment of iron deficiency anemia in non-dialysis-dependent chronic kidney disease (ND-CKD). Product-specific alterations in the metabolism of fibroblast growth factor 23 (FGF-23) leading to hypophosphatemia have been described for certain intravenous iron compounds, such as FCM, with potential effects on bone and cardiovascular health and quality of life. No prior head-to-head comparison between FCM and FDI exists in ND-CKD. This single-center exploratory double-blind randomized controlled trial primarily aimed to investigate the differential impact of FCM and FDI on FGF-23 and phosphate in patients with iron deficiency +/- anemia and ND-CKD (stages 3a-5 - serum ferritin <200 μg/L or serum ferritin 200-299 μg/L and transferrin saturation <20%). Patients were randomized (1:1) to receive either FCM or FDI over two infusions (1 month apart). Follow-up was 3 months. Measurements of serum intact FGF-23, phosphate, vitamin D metabolites, parathyroid hormone, other bone metabolism, cardiovascular, and quality of life markers were monitored. 168 patients were prescreened. Thirty-five patients were screened; 26 patients were randomized. The mean (standard deviation) age was 67.9 (12.4) years and 17 participants were male. Most participants had stage 4 CKD (median [interquartile range] estimated glomerular filtration rate [eGFR]: 18.0 [11.3] mL/min/1.73 m2). A higher than normal median (interquartile range) level of intact FGF-23 (212.1 [116.4] pg/mL) was noted. Serum phosphate was within normal range, while parathyroid hormone was higher and 1,25 (OH)2 vitamin D lower than the normal range. The "Iron and Phosphaturia - ExplorIRON-CKD" trial will provide important information regarding the differential effect of intravenous iron products in terms of FGF-23, phosphate, and other markers of bone and cardiovascular metabolism, alongside patient-reported outcome measures in patients with ND-CKD.

Hypophosphataemia following ferric derisomaltose and ferric carboxymaltose in patients with iron deficiency anaemia due to inflammatory bowel disease (PHOSPHARE-IBD): a randomised clinical trial

OBJECTIVE

Intravenous iron-a common treatment for anaemia and iron deficiency due to inflammatory bowel disease (IBD)-can cause hypophosphataemia. This trial compared the incidence of hypophosphataemia after treatment with ferric carboxymaltose (FCM) or ferric derisomaltose (FDI).

DESIGN

This randomised, double-blind, clinical trial was conducted at 20 outpatient hospital clinics in Europe (Austria, Denmark, Germany, Sweden, UK). Adults with IBD and iron deficiency anaemia (IDA) were randomised 1:1 to receive FCM or FDI at baseline and at Day 35 using identical haemoglobin- and weight-based dosing regimens. The primary outcome was the incidence of hypophosphataemia (serum phosphate <2.0 mg/dL) at any time from baseline to Day 35 in the safety analysis set (all patients who received ≥1 dose of study drug). Markers of mineral and bone homeostasis, and patient-reported fatigue scores, were measured.

RESULTS

A total of 156 patients were screened; 97 (49 FDI, 48 FCM) were included and treated. Incident hypophosphataemia occurred in 8.3% (4/48) FDI-treated patients and in 51.0% (25/49) FCM-treated patients (adjusted risk difference: -42.8% (95% CI -57.1% to -24.6%) p<0.0001). Both iron formulations corrected IDA. Patient-reported fatigue scores improved in both groups, but more slowly and to a lesser extent with FCM than FDI; slower improvement in fatigue was associated with greater decrease in phosphate concentration.

CONCLUSION

Despite comparably effective treatment of IDA, FCM caused a significantly higher rate of hypophosphataemia than FDI. Further studies are needed to address the longer-term clinical consequences of hypophosphataemia and to investigate mechanisms underpinning the differential effects of FCM and FDI on patient-reported fatigue.

Effect of Intravenous Iron Administration on Bone Mineral and Iron Homeostasis in Patients with Inflammatory Bowel Disease—Results of a Prospective Single-Centre Study

Introduction: Anaemia and bone metabolism alterations are common in inflammatory bowel disease (IBD), which is a heterogeneous group of diseases that include Crohn’s disease (CD) and ulcerative colitis (UC) with a rich intestinal and extraintestinal symptomatology. All these make the diagnostic procedures complicated and difficult. Purpose and scope: The aim of this study was to assess the effect of parenteral iron administration on biomarkers of mineral and bone homeostasis over time. Materials and methods: The study was a single-centre non-randomised prospective study. It was carried out between 2016 and 2020 in a group of patients in the Department of Internal Medicine and Gastroenterology Subunit of Inflammatory Bowel Diseases at the National Institute of Medicine of the Ministry of the Interior and Administration in Warsaw. At the first examination, the baseline disease severity, initial evaluation of anaemia (morphology, iron (Fe), total iron binding capacity (TIBC), ferritin, vitamin B12, folic acid) and bone mineral metabolism including C-reactive protein (CRP), albumins, alkaline phosphatase (ALP), Calcium, osteocalcin, phosphate in serum and in urine, parathyroid hormone (PTH), vitamin D3, fibroblast growth factor (iFGF23) and procollagen type 1N propeptide (P1NP) C-terminal telopeptide (CTX), was initially assessed. On the basis of peripheral blood counts, an appropriate dose of iron (iron derisomaltose or caboxymaltose) was administered. During the subsequent appointments on week 1, 4, and 12 morphology, iron (Fe), total iron binding capacity (TIBC), ferritin, vitamin B12, folic acid, C-reactive protein (CRP), albumins, alkaline phosphatase (ALP), Calcium, osteocalcin, phosphate in serum and in urine, parathyroid hormone (PTH), vitamin D3, fibroblast growth factor (iFGF23) and procollagen type 1N propeptide (P1NP) C-terminal telopeptide (CTX), were evaluated. Results: A total of 56 patients were enrolled into the study: 24 women and 32 men. In the group, 32 patients had Crohn’s disease (CD) and 24 had ulcerative colitis (UC). We found a statistically significant increase in the concentration of albumin (p = 0.031), haemoglobin (p < 0.001), haematocrit (p < 0.001), MCV (p < 0.001), MCHC (p = 0.001), iron (p < 0.001) and ferritin (p < 0.001) after the administration of parenteral iron. The influence of individual iron formulations on the analysed parameters (phosphate concentration in serum and in the urine, iFGF23, P1NP, PTH, vitamin D, haemoglobin and ferritin) was similar. Interestingly, an inverse correlation was found between the concentration of phosphorus in the blood and iFGF23 at certain time-points; however, in the study group they did not significantly affect the disturbances of calcium and phosphate metabolism. Conclusions: In the study group, transient and non-significant disorders of phosphate metabolism were found, which does not constitute a contraindication to treatment with parenteral iron in inflammatory bowel disease patients, which was safe and efficient.

Consensus guidelines for diagnosis and management of anemia in epidermolysis bullosa

BACKGROUND

Anemia is a common complication of severe forms of epidermolysis bullosa (EB). To date, there are no guidelines outlining best clinical practices to manage anemia in the EB population. The objective of this manuscript is to present the first consensus guidelines for the diagnosis and management of anemia in EB.

RESULTS

Due to the lack of high-quality evidence, a consensus methodology was followed. An initial survey exploring patient preferences, concerns and symptoms related to anemia was sent to EB patients and their family members. A second survey was distributed to EB experts and focused on screening, diagnosis, monitoring and management of anemia in the different types of EB. Information from these surveys was collated and used by the panel to generate 26 consensus statements. Consensus statements were sent to healthcare providers that care for EB patients through EB-Clinet. Statements that received more than 70% approval (completely agree/agree) were adopted.

CONCLUSIONS

The end result was a series of 6 recommendations which include 20 statements that will help guide management of anemia in EB patients. In patients with moderate to severe forms of EB, the minimum desirable level of Hb is 100 g/L. Treatment should be individualized. Dietary measures should be offered as part of management of anemia in all EB patients, oral iron supplementation should be used for mild anemia; while iron infusion is reserved for moderate to severe anemia, if Hb levels of > 80-100 g/L (8-10 g/dL) and symptomatic; and transfusion should be administered if Hb is < 80 g/L (8 g/dL) in adults and < 60 g/L (6 g/dL) in children.

Clinical and economic impact of ferric carboxymaltose treatment for iron deficiency in patients stabilized following acute heart failure: a multinational study

OBJECTIVE

To estimate clinical events and evaluate the financial implications of introducing ferric carboxymaltose (FCM) to treat iron deficiency (ID) at discharge in patients hospitalized for acute heart failure (AHF) with left ventricular ejection fraction (LVEF) <50% in the UK, Switzerland and Italy.

METHODS

A decision analytic cost-offset model was developed to evaluate the costs associated with introducing FCM for all eligible patients in three countries compared to a world without FCM, over a five-year time horizon. Data from AFFIRM-AHF clinical trial were used to model clinical outcomes, using an established cohort state-transition Markov model. Country-specific prevalence estimates were derived using data from real-world studies to extrapolate number of events and consequent cost totals to the population at risk on a national scale.

RESULTS

The cost-offset modeling demonstrated that FCM is projected to be a cost-saving intervention in all three country settings over a five-year time horizon. Savings were driven primarily by reduced hospitalizations and avoided cardiovascular deaths, with net cost savings of -£14,008,238, -CHF25,456,455 and -€105,295,146 incurred to the UK, Switzerland and Italy, respectively.

LIMITATIONS

Although AFFIRM-AHF was a multinational trial, efficacy data per country was not sufficiently large to enable country-specific analysis, therefore overall clinical parameters have been assumed to apply to all countries.

CONCLUSIONS

This study provides further evidence of the potential cost savings achievable by treating ID with FCM at discharge in patients hospitalized for AHF with LVEF <50%. The value of FCM treatment within the healthcare systems of the UK, Switzerland and Italy was demonstrated even within a limited time frame of one year, with consistent cost savings indicated over a longer term.

FGF23 AND ALTERED MINERAL HOMEOSTASIS IN KIDNEY DISEASE AND FOLLOWING INTRAVENOUS IRON

Fibroblast growth factor 23 (FGF23) is an endocrine hormone that stimulates renal phosphate excretion and suppresses circulating concentrations of 1,25-dihydroxyvitamin D (1,25D). These effects of FGF23 are most evident in rare diseases that are characterized by FGF23-mediated hypophosphatemic rickets-osteomalacia. More commonly, elevated FGF23 is a ubiquitous, early consequence of chronic kidney disease (CKD) in which it helps to maintain normal serum phosphate levels but causes secondary hyperparathyroidism by suppressing 1,25D, and directly promotes cardiovascular disease and death. Elevated FGF23 is also a common complication of intravenous administration of ferric carboxymaltose (FCM), which is widely used to treat iron deficiency anemia. Among patients with normal kidney function who receive FCM, the resulting increase in FGF23 and subsequent FGF23-mediated reduction of 1,25D and secondary hyperparathyroidism promote hypophosphatemia that can be symptomatic, severe, and associated with musculoskeletal complications. Ongoing research is needed to design novel therapeutic approaches to mitigate FGF23-related illnesses.

Ferric Carboxymaltose Versus Ferrous Fumarate in Anemic Children with Inflammatory Bowel Disease: The POPEYE Randomized Controlled Clinical Trial

OBJECTIVE

To determine whether intravenous (IV) or oral iron suppletion is superior in improving physical fitness in anemic children with inflammatory bowel disease (IBD).

STUDY DESIGN

We conducted a clinical trial at 11 centers. Children aged 8-18 with IBD and anemia (defined as hemoglobin [Hb] z-score < -2) were randomly assigned to a single IV dose of ferric carboxymaltose or 12 weeks of oral ferrous fumarate. Primary end point was the change in 6-minute walking distance (6MWD) from baseline, expressed as z-score. Secondary outcome was a change in Hb z-score from baseline.

RESULTS

We randomized 64 patients (33 IV iron and 31 oral iron) and followed them for 6 months. One month after the start of iron therapy, the 6MWD z-score of patients in the IV group had increased by 0.71 compared with -0.11 in the oral group (P = .01). At 3- and 6-month follow-ups, no significant differences in 6MWD z-scores were observed. Hb z-scores gradually increased in both groups and the rate of increase was not different between groups at 1, 3, and 6 months after initiation of iron therapy (overall P = .97).

CONCLUSION

In this trial involving anemic children with IBD, a single dose of IV ferric carboxymaltose was superior to oral ferrous fumarate with respect to quick improvement of physical fitness. At 3 and 6 months after initiation of therapy, no differences were discovered between oral and IV therapies. The increase of Hb over time was comparable in both treatment groups.

TRIAL REGISTRATION

NTR4487 [Netherlands Trial Registry].

Severe Hypophosphatemia Occurring After Repeated Exposure to a Parenteral Iron Formulation

Hypophosphatemia is a less known complication of parenteral iron use, particularly after the use of certain iron formulations. We report the case of a young male with inflammatory bowel disease and iron deficiency anemia, who developed severe symptomatic hypophosphatemia after his third exposure to iron carboxymaltose with no evidence of the same occurring upon prior exposures to the compound. Investigations revealed serum phosphorous levels of 0.7 mg/dl, corrected serum calcium of 8-9.5 mg/dl, alkaline phosphatase of 50 U/L (38-126), 25 hydroxy vitamin D level of 40.2 ng/ml, and intact PTH elevated to 207 pg/ml. Urine studies indicated renal phosphate wasting. Presentation was not in keeping with refeeding syndrome. Intact fibroblast growth factor 23 level, measured after the initiation of treatment was within the normal range at 179 RU/mL (44-215). 1,25 dihydroxy vitamin D level, also measured after the initiation of treatment, was normal at 26.3 pg/ml (19.9-79.3). The patient was treated with calcitriol and aggressive oral and intravenous phosphorous repletion. Symptoms then resolved and the patient was discharged on an oral regimen. This phenomenon is postulated to occur due to an increase in the level and activity of FGF23 and decreased cleavage of the same, due to anemia as well as use of specific iron formulations. This is the first instance, in our literature review, of this complication known to occur, not after initial exposure to an implicated iron formulation but occurring on subsequent exposure.

Patient blood management and patient safety

PURPOSE OF REVIEW

The particular fields within patient blood management (PBM) and patient safety reviewed here include novel insights into bleeding therapy, autologous cell salvage, and perioperative anemia therapy.

RECENT FINDING

World Health Organization has published that implementation of PBM is important but has not yet been performed in all hospitals. Two antibodies that mimic the function of FVIII, Emicizumab, and Mim8 have been developed. Tranexamic acid (TXA) has been investigated further in patients with hip surgery and shows reduction of bleeding. Thrombocytopenia in patients undergoing cardiac surgery is a particular concern that has been investigated in another trial. The use of autologous cell salvage was updated in form of a review and meta-analysis. And last but not least, intravenous iron in preoperative anemia therapy can reduce the number of transfusions, but especially iron carboxymaltose can cause hypophosphatemia.

SUMMARY

PBM should be further implemented in more hospitals. Emicizumab and Mim8 are indicated in acquired hemophilia or hemophilia A with inhibitors. TXA was confirmed to reduce bleeding. Autologous cell salvage is state of the art to reduce transfusion requirements in major cardiac and noncardiac surgery. Serum phosphate concentrations should be monitored after administration of intravenous iron compounds.

High-Dose Intravenous Iron with Either Ferric Carboxymaltose or Ferric Derisomaltose: A Benefit-Risk Assessment

The intravenous iron formulations ferric carboxymaltose (FCM) and ferric derisomaltose (FDI) offer the possibility of administering a large amount of iron in one infusion. This results in faster correction of anemia and the formulations being better tolerated than oral iron formulations. This triad of logistic advantages, improved patient convenience, and fast correction of anemia explains the fact that intravenous iron formulations nowadays are frequently prescribed worldwide in the treatment of iron deficiency anemia. However, these formulations may result in hypophosphatemia by inducing a strong increase in active fibroblast growth factor-23 (FGF-23), a hormone that stimulates renal phosphate excretion. This effect is much more pronounced with FCM than with FDI, and therefore the risk of developing hypophosphatemia is remarkably higher with FCM than with FDI. Repeated use of FCM may result in severe osteomalacia, which is characterized by bone pain, Looser zones (pseudofractures), and low-trauma fractures. Intravenous iron preparations are also associated with other adverse effects, of which hypersensitivity reactions are the most important and are usually the result of a non-allergic complement activation on nanoparticles of free labile iron-Complement Activation-Related Pseudo-Allergy (CARPA). The risk on these hypersensitivity reactions can be reduced by choosing a slow infusion rate. Severe hypersensitivity reactions were reported in < 1% of prospective trials and the incidence seems comparable between the two formulations. A practical guideline has been developed based on baseline serum phosphate concentrations and predisposing risk factors, derived from published cases and risk factor analyses from trials, in order to establish the safe use of these formulations.

Intravenous ferric derisomaltose in iron-deficient patients undergoing transcatheter aortic valve implantation due to severe aortic stenosis: study protocol of the randomised controlled IIISAS trial

INTRODUCTION

Iron deficiency is a prevalent comorbidity in patients with severe aortic stenosis and may be associated with procedural and clinical outcomes after transcatheter aortic valve implantation (TAVI). In the Intravenous Iron Supplement for Iron Deficiency in Patients with Severe Aortic Stenosis (IIISAS) trial, we aim to examine whether a single administration of ferric derisomaltose can improve physical capacity after TAVI.

METHODS AND ANALYSIS

This randomised, double-blind, placebo-controlled trial aims to enrol 150 patients with iron deficiency who are scheduled for TAVI due to severe aortic stenosis. The study drug and matching placebo are administered approximately 3 months prior to TAVI, and the patients are followed for 3 months after TAVI. Inclusion criteria are iron deficiency, defined as serum ferritin<100 µg/L or ferritin between 100 and 300 µg/L in combination with a transferrin saturation<20% and written informed consent. Exclusion criteria include haemoglobin<10 g/dL, red blood cell disorders, end-stage kidney failure, intolerance to ferric derisomaltose, and ongoing infections. The primary endpoint is the baseline-adjusted distance walked on a 6 min walk test (6MWT) 3 months after TAVI. Secondary end points include quality of life, New York Heart Association functional class (NYHA functional class), and skeletal muscle strength.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Regional Committee for Medical and Health Research of South-Eastern Norway and The Norwegian Medicines Agency. Enrolment has begun, and results are expected in 2022. The results of the IIISAS trial will be disseminated by presentations at international and national conferences and by publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04206228.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Osteomalacia as a Complication of Intravenous Iron Infusion: A Systematic Review of Case Reports

Randomized control trials (RCTs) have shown that certain intravenous iron preparations can induce high levels of fibroblast growth factor 23 (FGF-23) and persistent hypophosphatemia. Repeated iron infusions may lead to prolonged hypophosphatemia and osteomalacia events not captured by RCTs. Several previous case reports have described skeletal adverse effects after repeated iron infusions. To characterize these effects, we conducted a systematic review of case reports. MEDLINE, Embase, Web of Science, and Cochrane databases were searched in March 2021. We selected case reports of patients ≥16 years old. Study quality was assessed using the tool from Murad and colleagues. We report the results in a narrative summary. We identified 28 case reports, reporting 30 cases. Ages ranged from 28 to 80 years (median 50 years). Most patients (n = 18) received ferric carboxymaltose (FCM), whereas 8 received saccharated ferric oxide (SFO) and 3 received iron polymaltose (IPM). All but 2 cases had more than five infusions (range 2 to 198, median 17). The lowest phosphate levels ranged from 0.16 to 0.77 mmol/L (median 0.36 mmol/L). Intact FGF-23 (iFGF-23) was high when measured. Serum 25OH vitamin D was low in 10 of 21 cases measured and 1,25(OH)₂ vitamin D in 12 of 18. Alkaline phosphatase was high in 18 of 22 cases. Bone or muscle pain was reported in 28 of the 30 cases. Twenty patients had pseudofractures, 9 had fractures, and 6 patients had both. All 15 available bone scans showed focal isotope uptake. Case reports tend to report severe cases, so potential reporting bias should be considered. Osteomalacia is a potential complication of repeated iron infusion, especially in patients with gastrointestinal disorders receiving prolonged therapy. Pain and fractures or pseudofractures are common clinical findings, associated with low phosphate, high iFGF-23, high alkaline phosphatase, and abnormal isotope bone scan. Discontinuing or switching the iron formulation was an effective intervention in most cases. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Risk Factors for and Effects of Persistent and Severe Hypophosphatemia Following Ferric Carboxymaltose

CONTEXT

Hypophosphatemia, osteomalacia, and fractures are complications of certain intravenous iron formulations.

OBJECTIVE

This study investigated risk factors for incident, severe, and persistent hypophosphatemia, and associated alterations in bone and mineral biomarkers following intravenous iron treatment.

METHODS

We analyzed data from the PHOSPHARE-IDA randomized clinical trials, comprising 245 patients aged 18 years or older with iron deficiency anemia at 30 outpatient clinics in the United States who received intravenous ferric carboxymaltose (FCM) or ferric derisomaltose (FDI). Outcome measures included serum phosphate, intact fibroblast growth factor-23 (iFGF23), 1,25-dihydroxyvitamin D (1,25(OH)2D), ionized calcium, parathyroid hormone (PTH), and alkaline phosphatase.

RESULTS

FCM was the only consistent risk factor for incident hypophosphatemia (< 2.0 mg/dL; odds ratio vs FDI: 38.37; 95% CI: 16.62, 88.56; P < 0.001). Only FCM-treated patients developed severe hypophosphatemia (< 1.0 mg/dL; 11.3%; 13/115) or persistent hypophosphatemia (< 2.0 mg/dL at study end; 40.0%; 46/115). More severe hypophosphatemia associated with significantly greater increases in iFGF23, PTH, and alkaline phosphatase, and more severe decreases in 1,25(OH)2D and ionized calcium (all P < 0.05). Patients with persistent vs resolved hypophosphatemia demonstrated significantly greater changes in iFGF23, PTH, 1,25(OH)2D, and N-terminal procollagen-1 peptide levels (all P < 0.01), but alkaline phosphatase increased similarly in both groups.

CONCLUSION

Treatment with FCM was the only consistent risk factor for hypophosphatemia. Patients who developed severe or persistent hypophosphatemia after FCM treatment manifested more severe derangements in bone and mineral metabolism. Changes in bone biomarkers continued beyond resolution of hypophosphatemia, suggesting ongoing effects on bone that may help explain the association of FCM with osteomalacia and fractures.

Safety of Ferric Carboxymaltose in Children: Report of a Case Series from Greece and Review of the Literature

BACKGROUND

Parenteral iron is generally considered safe in adults, and severe adverse events are extremely rare. Ferric carboxymaltose (FCM), a third-generation parenteral iron product, is not licensed for pediatric use.

OBJECTIVE

The aim of this study was to present our data on the safety of FCM in children with iron deficiency (ID) and/or iron deficiency anemia (IDA) and to investigate through a systematic literature review articles reporting on the safety of FCM use in children with ID/IDA.

PATIENTS AND METHODS

Safety data regarding children treated with FCM for ID/IDA from four pediatric departments in Greece over a 26-month period are presented. Additionally, a literature search was performed in PubMed, Scopus, and Google Scholar on December 4, 2021 for articles reporting on the use of FCM in children with ID/IDA. Review articles, guidelines, case reports/case series, and reports on the use of FCM for conditions other than ID/IDA were excluded. Identified articles were screened for all reported adverse events (AE) that were graded according to the Common Terminology Criteria for Adverse Events, version 5.0.

RESULTS

In our cohort, 37 children with ID/IDA received 41 FCM infusions. All infusions were tolerated well. In addition, 11 articles reporting 1231 infusions of FCM in 866 children were identified in the literature. Among them, 52 (6%) children developed AE that were graded as mild or moderate (grades I-III).

CONCLUSIONS

Our patient cohort and this literature review provide further evidence for the good safety profile of FCM in children, although well-designed prospective clinical trials with appropriate safety endpoints are still required.

Efficacy and safety of ferric derisomaltose (FDI) compared with iron sucrose (IS) in patients with iron deficiency anemia after bariatric surgery

Purpose

Iron deficiency is common following bariatric surgery, and treatment with intravenous iron is often required. This post hoc analysis of data from two randomized, open-label, multicenter trials evaluated the efficacy and safety of ferric derisomaltose (FDI; formerly iron isomaltoside 1000) versus iron sucrose (IS) over 4 weeks in adults with iron deficiency anemia (IDA) resulting from prior bariatric surgery.

Materials and methods

Data were pooled for participants who received FDI or IS in the PROVIDE or FERWON-IDA trials for the treatment of IDA post bariatric surgery. Efficacy outcomes included changes in hemoglobin (Hb) and iron parameters; safety outcomes included the incidence of adverse drug reactions (ADRs), serious or severe hypersensitivity reactions (HSRs), and hypophosphatemia.

Results

The analysis included 159 patients. Mean (standard deviation) cumulative iron doses were 1199 (± 347) mg for FDI and 937 (± 209) mg for IS. Compared with IS, FDI resulted in a faster and more pronounced Hb response, and a higher proportion of responders (Hb level increase ≥ 2 g/dL from baseline) at all time points. The incidence of ADRs was similar with FDI and IS (15.1% and 18.2%, respectively), with no serious ADRs or serious or severe HSRs reported. The incidence of hypophosphatemia was low and similar in both treatment groups, with no cases of severe hypophosphatemia observed.

Conclusions

In patients with IDA resulting from bariatric surgery, FDI produced a faster and more pronounced Hb response than IS. Both FDI and IS were well tolerated.

Graphical abstract

Hypophosphatemia after intravenous iron therapy: Comprehensive review of clinical findings and recommendations for management

Contemporary intravenous iron formulations allow administration of high doses of elemental iron and enable correction of total iron deficit in one or two infusions. An important but underappreciated complication of certain formulations is hypophosphatemia caused by increased secretion of the phosphaturic hormone, fibroblast growth factor 23 (FGF23). The pathophysiology of FGF23-induced hypophosphatemia due to certain intravenous iron formulations has been recently investigated in prospective clinical trials. To reach the correct diagnosis, clinicians must recognize the typical clinical manifestations of intravenous iron-induced hypophosphatemia and identify a specific pattern of biochemical changes (hyperphosphaturic hypophosphatemia triggered by high FGF23 that causes low 1,25 (OH)₂ vitamin D, hypocalcemia and secondary hyperparathyroidism). Physicians and patients should be aware of hypophosphatemia as a common complication of intravenous iron therapy and monitor serum phosphate concentrations in patients receiving repeated doses of specific intravenous iron formulations. Symptoms of hypophosphatemia are associated with severity and duration. Persistent hypophosphatemia can occur with iron therapy and can cause debilitating diseases including myopathy, osteomalacia and fractures. This review summarizes the current understanding of the iron-phosphate axis as well as complications of intravenous iron-induced hypophosphatemia.

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.

Rationale and design of the intravenous iron for treatment of anemia before cardiac surgery trial

Background Approximately 20% to 30% of patients awaiting cardiac surgery are anemic. Anemia increases the likelihood of requiring a red cell transfusion and is associated with increased complications, intensive care, and hospital stay following surgery. Iron deficiency is the commonest cause of anemia and preoperative intravenous (IV) iron therapy thus may improve anemia and therefore patient outcome following cardiac surgery. We have initiated the intravenous iron for treatment of anemia before cardiac surgery (ITACS) Trial to test the hypothesis that in patients with anemia awaiting elective cardiac surgery, IV iron will reduce complications, and facilitate recovery after surgery. Methods ITACS is a 1,000 patient, international randomized trial in patients with anemia undergoing elective cardiac surgery. The patients, health care providers, data collectors, and statistician are blinded to whether patients receive IV iron 1,000 mg, or placebo, at 1-26 weeks before their planned date of surgery. The primary endpoint is the number of days alive and at home up to 90 days after surgery. Results To date, ITACS has enrolled 615 patients in 30 hospitals in 9 countries. Patient mean (SD) age is 66 (12) years, 63% are male, with a mean (SD) hemoglobin at baseline of 118 (12) g/L; 40% have evidence (ferritin <100 ng/mL and/or transferrin saturation <25%) suggestive of iron deficiency. Most (59%) patients have undergone coronary artery surgery with or without valve surgery. Conclusions The ITACS Trial will be the largest study yet conducted to ascertain the benefits and risks of IV iron administration in anemic patients awaiting cardiac surgery.

Ironing out mechanisms of iron homeostasis and disorders of iron deficiency

Iron plays an important role in mammalian physiological processes. It is a critical component for the function of many proteins, including enzymes that require heme and iron-sulfur clusters. However, excess iron is also detrimental because of its ability to catalyze the formation of reactive oxygen species. As a result, cellular and systemic iron levels are tightly regulated to prevent oxidative damage. Iron deficiency can lead to a number of pathological conditions, the most prominent being anemia. Iron deficiency should be corrected to improve adult patients' symptoms and to facilitate normal growth during fetal development and childhood. However, inappropriate use of intravenous iron in chronic conditions, such as cancer and heart failure, in the absence of clear iron deficiency can lead to unwanted side effects. Thus, this form of therapy should be reserved for certain patients who cannot tolerate oral iron and need rapid iron replenishment. Here, we will review cellular and systemic iron homeostasis and will discuss complications of iron deficiency.

Skeletal endocrinology: where evolutionary advantage meets disease

The regulation of whole-body homeostasis by the skeleton is mediated by its capacity to secrete endocrine signaling molecules. Although bone-derived hormones confer several adaptive benefits, their physiological functions also involve trade-offs, thus eventually contributing to disease. In this manuscript, we discuss the origins and functions of two of the best-studied skeletal mediators, fibroblast growth factor 23 and osteocalcin, in an evolutionary context. Moreover, we provide a theoretical framework seeking to explain the broad involvement of these two hormones in amniote physiology as well as their potential to fuel the development and progression of diseases. Vice versa, we outline which perturbations might be amenable to manipulation of these systems and discuss limitations and ongoing challenges in skeletal endocrine research. Finally, we summarize unresolved questions and potential future studies in this thriving field.

Hypophosphataemia, fibroblast growth factor 23 and third-generation intravenous iron compounds: a narrative review

Third-generation intravenous (i.v.) iron preparations are safe and efficacious and are increasingly used in the treatment of iron-deficiency anaemia. Hypophosphataemia is emerging as an established side-effect following the administration of certain compounds. Symptoms of hypophosphataemia can be masked by their similarity to those of iron-deficiency anaemia and both acute and chronic hypophosphataemia can be detrimental. Hypophosphataemia appears to be linked to imbalances in the metabolism of the phosphatonin fibroblast growth factor 23. In this narrative review, we discuss the possible pathophysiology behind this phenomenon, the studies comparing third-generation i.v. iron compounds, and the potential implications of the changes in fibroblast growth factor 23 and hypophosphataemia. We also present an algorithm of how to approach such patients requiring i.v. iron in anticipation of hypophosphataemia and how the impact related to it can be minimized.