Clinical data for intravenous iron - debunking the hype around hypersensitivity

[Iron supplementation in patients with chronic inflammatory bowel disease: recommendations for a practical approach]

Iron deficiency is the predominant cause of anemia. Iron deficiency anemia plays a major role, especially in patients with inflammatory bowel disease (IBD), and is the most common extraintestinal manifestation and IBD-associated systemic complication. The presence of anemia leads to a reduction in quality of life in patients with IBD associated with limitations in physical, emotional, and cognitive function. In addition, it is associated with an increased hospitalization rate. For this reason, iron supplementation is of particular importance. Oral and intravenous iron supplements are used to treat iron deficiency. Due to the lack of absorption and gastrointestinal side effects of oral substitution, intravenous supplementation is becoming increasingly important. However, there are still certain concerns about intravenous administration.With the help of this review, we want to address the topic of iron substitution in patients with IBD, summarize current guideline recommendations, and provide a practical approach.

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.

Iron Deficiency Related to Obesity

There is a direct correlation between being overweight and iron deficiency. Physiological changes occur in obese adipose cells that contribute to the development of iron deficiency (ID) and iron deficiency anemia (IDA). These changes disrupt the normal iron metabolic checks and balances. Furthermore, bariatric surgery can lead to long-term ID and IDA. Oral iron supplementation may not be effective for many of these patients. Intravenous iron infusions can significantly increase the quality of life for individuals experiencing this condition but are also associated with potentially serious complications. Adequate knowledge about intravenous (IV) iron administration can greatly increase the safety of this beneficial therapy. This review article explains the relationship between obesity, ID/IDA, bariatric surgery and the safe administration of IV iron.

Intravenous iron versus blood transfusion for postpartum anemia: a systematic review and meta-analysis

BACKGROUND

Intravenous iron (IV-iron) is used as an alternative to, or alongside, red blood cell transfusion (RBC-T) to treat more severe postpartum anemia (PPA), although optimal treatment options remain unclear. No previous systematic reviews have examined IV-iron and RBC-T, including patient-reported outcomes and hematological responses.

METHODS

A systematic review and meta-analysis of randomized trials comparing IV-iron and RBC-T with each other, oral iron, no treatment, and placebo for the treatment of PPA. Key inclusion criteria were PPA (hemoglobin < 12 g/dL) and IV-iron or RBC-T as interventions. Key exclusion criteria were antenatal IV-iron or RBC-T. Fatigue was the primary outcome. Secondary outcomes included hemoglobin and ferritin concentrations, and adverse events. From 27th August 2020 to 26th September 2022, databases, registries, and hand searches identified studies. A fixed-effect meta-analysis was undertaken using RevMan (5.4) software. The quality of the studies and the evidence was assessed using the Cochrane Risk of Bias table, and Grading of Recommendations, Assessment, Development, and Evaluation. This review is registered with the Prospective Register of Systematic Reviews (CRD42020201115).

RESULTS

Twenty studies and 4196 participants were included: 1834 assigned IV-iron, 1771 assigned oral iron, 330 assigned RBC-T, and 261 assigned non-intervention. Six studies reported the primary outcome of fatigue (1251 participants). Only studies of IV-iron vs. oral iron (15 studies) were available for meta-analysis. Of these, three reported on fatigue using different scales; two were available for meta-analysis. There was a significant reduction in fatigue with IV-iron compared to oral iron (standardized mean difference - 0.40, 95% confidence interval (CI) - 0.62, - 0.18, I2 = 0%). The direction of effect also favored IV-iron for hemoglobin (mean difference (MD) 0.54 g/dL, 95% confidence interval (CI) 0.47, 0.61, I2 = 91%), ferritin, (MD 58.07 mcg/L, 95% CI 55.74, 60.41, I2 = 99%), and total adverse events (risk-ratio 0.63, 95% CI 0.52, 0.77, I2 = 84%). The overall quality of the evidence was low-moderate.

DISCUSSION

For all outcomes, the evidence for RBC-T, compared to IV-iron, non-intervention, or dose effects of RBC-T is very limited. Further research is needed to determine whether RBC-T or IV-iron for the treatment of PPA is superior for fatigue and hematological outcomes.

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.

Lessons learned from immunological characterization of nanomaterials at the Nanotechnology Characterization Laboratory

Nanotechnology carriers have become common in pharmaceutical products because of their benefits to drug delivery, including reduced toxicities and improved efficacy of active pharmaceutical ingredients due to targeted delivery, prolonged circulation time, and controlled payload release. While available examples of reduced drug toxicity through formulation using a nanocarrier are encouraging, current data also demonstrate that nanoparticles may change a drug’s biodistribution and alter its toxicity profile. Moreover, individual components of nanoparticles and excipients commonly used in formulations are often not immunologically inert and contribute to the overall immune responses to nanotechnology-formulated products. Said immune responses may be beneficial or adverse depending on the indication, dose, dose regimen, and route of administration. Therefore, comprehensive toxicology studies are of paramount importance even when previously known drugs, components, and excipients are used in nanoformulations. Recent data also suggest that, despite decades of research directed at hiding nanocarriers from the immune recognition, the immune system’s inherent property of clearing particulate materials can be leveraged to improve the therapeutic efficacy of drugs formulated using nanoparticles. Herein, I review current knowledge about nanoparticles’ interaction with the immune system and how these interactions contribute to nanotechnology-formulated drug products’ safety and efficacy through the lens of over a decade of nanoparticle characterization at the Nanotechnology Characterization Laboratory.

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.

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

Recent and Emerging Therapies for Iron Deficiency in Anemia of CKD: A Review

Iron deficiency commonly contributes to the anemia affecting individuals with chronic kidney disease. Diagnostic criteria for iron deficiency in chronic kidney disease are explained. Mechanisms of functional and absolute iron deficiency and general treatment Principles as delineated in the Kidney Disease: Improving Global Outcomes guidelines are reviewed. Repletion of absolute iron deficits has progressed over time with the addition of better tolerated, more effective oral agents including ferric citrate, ferric maltol, and sucrosomial iron. Structural characteristics and trial data enabling regulatory approval of these novel oral agents are examined. Newer intravenous iron therapies including ferric carboxymaltose and ferric derisomaltose allow for fewer infusions and decreased risk of serious hypersensitivity reactions. Concerns about adverse events including cardiovascular events and infections are discussed. The potential risk of 6H syndrome due to these intravenous agents, including hypophosphatemia, osteomalacia, and pathologic fractures is emphasized. The proposed pathophysiology of 6H syndrome and hypophosphatemia is described. Ferric pyrophosphate citrate enables administration of iron for repletion through dialysate. Relative merits, costs, and risks of various iron agents such as hypersensitivity and 6H syndrome/hypophosphatemia are summarized.

Intravenous ferric derisomaltose for the treatment of iron deficiency anemia

Intravenous (IV) iron is the therapy of choice when oral iron is ineffective or poorly tolerated, yet use has been limited by fears of hypersensitivity reactions (HSRs). Newer formulations that bind iron more tightly and release it more slowly have made the risk of serious or severe HSRs very low. One such formulation, ferric derisomaltose, has been approved in the United States for delivery of 1000 mg iron in a single IV infusion. Ferric derisomaltose rapidly repletes iron parameters with low rates of serious or severe HSRs. Single-infusion iron repletion offers convenience, eliminates adherence concerns, and reduces healthcare resource utilization.

Newer formulations of intravenous iron: a review of their chemistry and key safety aspects - hypersensitivity, hypophosphatemia, and cardiovascular safety

Introduction: The newest intravenous (IV) iron products show an improved safety profile over predecessors, allowing for the rapid administration of relatively high doses. Ferric derisomaltose (FDI; also known as iron isomaltoside), ferric carboxymaltose (FCM), and ferumoxytol (FER), are successful treatments for iron deficiency (Europe; FDI and FCM) and iron deficiency anemia (US; FDI, FCM, and FER).Areas covered: This review focusses on the chemistry and structure of FDI, FCM, and FER, and on three key aspects of IV iron safety: (1) hypersensitivity; (2) hypophosphatemia and sequelae; (3) cardiovascular safety.Expert opinion: Although the safety of modern IV iron has improved, immediate infusion reactions and the development of hypophosphatemia must be appreciated and recognized by those who prescribe and administer IV iron. Immediate infusion reactions can occur with any IV iron and are usually mild; severe reactions - particularly anaphylaxis - are extremely rare. The recognition and appropriate management of infusion reactions is an important consideration to the successful administration of IV iron. Severe, persistent, hypophosphatemia is a specific side effect of FCM. No cardiovascular safety signal has been identified for IV iron. Ongoing trials in heart failure will provide additional long-term efficacy and safety data.

Are Pregnant Women Who Are Living with Overweight or Obesity at Greater Risk of Developing Iron Deficiency/Anaemia?

Low-grade inflammation is often present in people living with obesity. Inflammation can impact iron uptake and metabolism through elevation of hepcidin levels. Obesity is a major public health issue globally, with pregnant women often affected by the condition. Maternal obesity is associated with increased pregnancy risks including iron deficiency (ID) and iron-deficiency anaemia (IDA)-conditions already highly prevalent in pregnant women and their newborns. This comprehensive review assesses whether the inflammatory state induced by obesity could contribute to an increased incidence of ID/IDA in pregnant women and their children. We discuss the challenges in accurate measurement of iron status in the presence of inflammation, and available iron repletion strategies and their effectiveness in pregnant women living with obesity. We suggest that pre-pregnancy obesity and overweight/obese pregnancies carry a greater risk of ID/IDA for the mother during pregnancy and postpartum period, as well as for the baby. We propose iron status and weight gain during pregnancy should be monitored more closely in women who are living with overweight or obesity.

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.

An evaluation of ferric derisomaltose as a treatment for anemia

Introduction: Originally approved in Europe in 2009, ferric derisomaltose is the most recently authorized intravenous iron compound in the United States of America (2020). Ferric derisomaltose given as a rapid high-dose infusion can allow complete iron repletion in a single dose and it is now widely used in the treatment of iron deficiency. Areas covered: The chemistry, pharmacodynamics and pharmacokinetics of ferric derisomaltose are reviewed. Results from phase II, III and IV trials regarding efficacy and safety are presented. Mechanisms behind minor infusion reactions, hypersensitivity and hypophosphatemia are discussed. The economic impact of ferric derisomaltose use is presented. Data pertaining to the use of ferric derisomaltose in iron deficiency anemia, chronic kidney disease, inflammatory bowel disease, chronic heart failure, perioperative care and other patient groups are comprehensively covered. Expert opinion: Ferric derisomaltose is an effective intravenous iron formulation with a good safety profile, providing rapid, cost-effective iron repletion. Ferric derisomaltose releases low quantities of labile iron relative to older compounds. Anaphylaxis is extremely rare, and 'Fishbane' reactions are uncommon. Hypophosphatemia following ferric derisomaltose administration is infrequent in comparison to other intravenous irons such as ferric carboxymaltose. The scope of ferric derisomaltose use is growing with increasing research in these areas.

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.

Incidence of Iron Deficiency and the Role of Intravenous Iron Use in Perioperative Periods

Iron deficiency is a major problem in worldwide populations, being more alarming in surgical patients. In the presence of absolute iron deficiency (depletion of body iron), functional iron deficiency (during intense bone marrow stimulation by endogenous or exogenous factors), or iron sequestration (acute or chronic inflammatory conditions), iron-restricted erythropoiesis can develop. This systemic review was conducted to draw attention to the delicate problem of perioperative anemia, and to provide solutions to optimize the management of anemic surgical patients. Systemic reviews and meta-analyses, clinical studies and trials, case reports and international guidelines were studied, from a database of 50 articles. Bone marrow biopsy, serum ferritin levels, transferrin saturation, the mean corpuscular volume, and mean corpuscular hemoglobin concentration were used in the diagnosis of iron deficiency. There are various intravenous iron formulations, with different pharmacological profiles used for restoring iron. In surgical patients, anemia is an independent risk factor for morbidity and mortality. Therefore, anemia correction should be rapid, with parenteral iron formulations—the oral ones—being inefficient. Various studies showed the safety and efficacy of parenteral iron formulations in correcting hemoglobin levels and decreasing the blood transfusion rate, the overall mortality, the postoperative infections incidence, hospitalization days, and the general costs.