Worse Outcomes of Patients With HFE Hemochromatosis With Persistent Increases in Transferrin Saturation During Maintenance Therapy

Rusfertide for the treatment of iron overload in HFE-related haemochromatosis: an open-label, multicentre, proof-of-concept phase 2 trial

BACKGROUND

Hereditary haemochromatosis protein (HFE)-related haemochromatosis, an inherited iron overload disorder caused by insufficient hepcidin production, results in excessive iron absorption and tissue and organ injury, and is treated with first-line therapeutic phlebotomy. We aimed to investigate the efficacy and safety of rusfertide, a peptidic mimetic of hepcidin, in patients with HFE-related haemochromatosis.

METHODS

This open-label, multicentre, proof-of-concept phase 2 trial was done across nine academic and community centres in the USA and Canada. Adults (aged ≥18 years) with HFE-related haemochromatosis on a stable therapeutic phlebotomy regimen (maintenance phase) for at least 6 months before screening and who had a phlebotomy frequency of at least 0·25 per month (eg, at least three phlebotomies in 12 months or at least four phlebotomies in 15 months) and less than one phlebotomy per month, with serum ferritin of less than 300 ng/mL and haemoglobin of more than 11·5 g/dL, were eligible. Patients initiated 24 weeks of subcutaneous rusfertide treatment within 7 days of a scheduled phlebotomy at 10 mg once weekly. Rusfertide doses and dosing schedules could be adjusted to maintain serum transferrin iron saturation (TSAT) at less than 40%. During rusfertide treatment, investigators were to consider the need for phlebotomy when the serum ferritin and TSAT values exceeded the patient's individual pre-phlebotomy serum ferritin and TSAT values. No primary endpoint or testing hierarchy was prespecified. Prespecified efficacy endpoints included the change in the frequency of phlebotomies; the proportion of patients achieving phlebotomy independence; change in serum iron, TSAT, serum transferrin, serum ferritin, and liver iron concentration (LIC) as measured by MRI; and treatment-emergent adverse events (TEAEs). The key efficacy analyses for phlebotomy rate and LIC were conducted by use of paired t tests in the intention-to-treat population, defined as all patients who received any study drug and who had pretreatment and at least one post-dose measurement. We included all participants who received at least one dose of rusfertide in the safety analyses. This trial is closed and completed and is registered with ClinicalTrials.gov, NCT04202965.

FINDINGS

Between March 11, 2020, and April 23, 2021, 28 patients were screened and 16 (ten [63%] men and six [38%] women) were enrolled. 16 were included in analyses of phlebotomy endpoints and 14 for the LIC endpoint. 12 (75%) patients completed 24 weeks of treatment. The mean number of phlebotomies was significantly reduced during the 24-week rusfertide treatment (0·06 phlebotomies [95% CI -0·07 to 0·20]) compared with 24 weeks pre-study (2·31 phlebotomies [95% CI 1·77 to 2·85]; p<0·0001). 15 (94%) of 16 patients were phlebotomy-free during the treatment period. Mean LIC in the 14 patients in the intention-to-treat population was 1·4 mg iron per g dry liver weight (95% CI 1·0 to 1·8) at screening and 1·1 mg iron per g dry liver weight (95% CI 0·9 to 1·3) at the end of treatment (p=0·068). Mean TSAT was 45·3% (95% CI 33·2 to 57·3) at screening, 36·7% (24·2 to 49·2) after the pretreatment phlebotomy, 21·8% (15·8 to 27·9) 24 h after the first dose of rusfertide, 40·4% (27·1 to 53·8) at the end of treatment, and 32·6% (25·0 to 40·1) over the treatment duration. Mean serum iron was 24·6 μmol/L (95% CI 18·6 to 30·6), 20·1 μmol/L (14·8 to 25·3), 11·9 μmol/L (9·2 to 14·7), 22·5 μmol/L (15·9 to 29·1), and 19·0 μmol/L (15·3 to 22·6) at these same timepoints, respectively. Mean serum ferritin was 83·3 μg/L (52·2 to 114.4), 65·5 μg/L (32·1 to 98·9), 62·8 μg/L (33·8 to 91·9), 150·0 μg/L (86·6 to 213.3), and 94·3 μg/L (54·9 to 133.6) at these same timepoints, respectively. There were only minor changes in serum transferrin concentration. 12 (75%) patients had at least one TEAE, the most common of which was injection site pain (five [31%] patients). All TEAEs were mild or moderate in severity, except for a serious adverse event of pancreatic adenocarcinoma, which was considered severe and unrelated to treatment and was pre-existing and diagnosed 21 days after starting rusfertide treatment.

INTERPRETATION

Rusfertide prevents iron re-accumulation in the absence of phlebotomies and could be a viable therapeutic option for selected patients with haemochromatosis.

FUNDING

Protagonist Therapeutics.

[Hereditary Liver Diseases: Wilson's Disease and Hemochromatosis]

Wilson's disease and HFE-hemochromatosis are autosomal-recessively inherited metabolic diseases of the liver. Copper overload in case of Wilson's disease and iron overload in case of hemochromatosis lead to organ damage of the liver and other organs. In order to diagnose these diseases at an early stage and introduce therapy, knowledge of the symptoms and diagnostic criteria of these diseases is important. Iron overload in hemochromatosis patients is treated with phlebotomies and copper overload in Wilson's disease patients with either chelating medications (D-penicillamine or trientine) or zinc salts. After introduction of lifelong therapy both diseases typically have a favorable disease course and further development of organ-damage can be prevented, especially with respect to liver-damage.

Patient-reported outcomes and their relation with iron parameters in HFE haemochromatosis during maintenance therapy: A prospective cohort study

BACKGROUND & AIMS

The standard of care for haemochromatosis is regular phlebotomy in order to maintain low ferritin levels. Many patients report fatigue or joint pain despite serum ferritin within the therapeutic targets. We evaluated Patient-Reported Outcomes, and their relation with iron parameters, in C282Y homozygous patients undergoing maintenance phlebotomy.

METHODS

Patients were prospectively enrolled in a French referral care centre. At each phlebotomy, patients completed a numeric fatigue scale, a joint pain questionnaire and SF-36 Mental Component Score (MCS) and Physical Component Score (PCS). Haemoglobin, iron, TS and ferritin were collected concomitantly.

RESULTS

About 701 visits were performed in 259 patients. The median fatigue score was 3/10; 171 (66%) patients reported joint pain. Age and worsening of joint pain were associated with fatigue (p < .0001 for both). Female gender (p < .037), age (p < .003), and a decrease of TS (p = .050) were associated with joint pain. Main features associated with PCS <50 were worsening of joint pain and age (p < .001 for both) and TS <20% (p < .02).

CONCLUSIONS

Fatigue was independent from iron parameters. The main factor impacting quality of life was joint pain, which was more severe in patients with low TS values. Then, a more precise monitoring of TS should be proposed during haemochromatosis maintenance therapy; while less stringent monitoring of serum ferritin levels could be tested.

Genetic Causal Association between Iron Status and Osteoarthritis: A Two-Sample Mendelian Randomization

Objective: Observational studies have shown the association between iron status and osteoarthritis (OA). However, due to difficulties of determining sequential temporality, their causal association is still elusive. Based on the summary data of genome-wide association studies (GWASs) of a large-scale population, this study explored the genetic causal association between iron status and OA. Methods: First, we took a series of quality control steps to select eligible instrumental SNPs which were strongly associated with exposure. The genetic causal association between iron status and OA was analyzed using the two-sample Mendelian randomization (MR). Inverse-variance weighted (IVW), MR-Egger, weighted median, simple mode, and weighted mode methods were used for analysis. The results were mainly based on IVW (random effects), followed by sensitivity analysis. IVW and MR-Egger were used for heterogeneity testing. MR-Egger was also used for pleiotropy testing. Leave-one-SNP-out analysis was used to identify single nucleotide polymorphisms (SNPs) with potential impact. Maximum likelihood, penalized weighted median, and IVW (fixed effects) were performed to further validate the reliability of results. Results: IVW results showed that transferrin saturation had a positive causal association with knee osteoarthritis (KOA), hip osteoarthritis (HOA) and KOA or HOA (p < 0.05, OR > 1), and there was a negative causal association between transferrin and HOA and KOA or HOA (p < 0.05, OR < 1). The results of heterogeneity test showed that our IVW analysis results were basically free of heterogeneity (p > 0.05). The results of the pleiotropy test showed that there was no pleiotropy in our IVW analysis (p > 0.05). The analysis results of maximum likelihood, penalized weighted median and IVW (fixed effects) were consistent with our IVW results. No genetic causal association was found between serum iron and ferritin and OA. Conclusions: This study provides evidence of the causal association between iron status and OA, which provides novel insights to the genetic research of OA.

Arthritis Prediction of Advanced Hepatic Fibrosis in HFE Hemochromatosis

OBJECTIVE

To evaluate whether arthritis predicts the likelihood of advanced hepatic fibrosis in HFE hemochromatosis.

PATIENTS AND METHODS

We conducted a retrospective, cross-sectional analysis of 112 well-characterized patients with HFE hemochromatosis and liver biopsy-validated fibrosis staging recruited between January 1, 1983, and December 31, 2013. Complete clinical, biochemical, hematologic, and noninvasive serum biochemical indices (aspartate aminotransferase to platelet ratio index [APRI] and fibrosis 4 index [FIB4]) were available. Scheuer fibrosis stages 3 and 4, APRI greater than 0.44, or FIB4 greater than 1.1 were used to define advanced hepatic fibrosis. Comparisons between groups were performed using categorical analysis, unpaired or paired t test.

RESULTS

Male (n=76) and female (n=36) patients were similar in age. Nineteen patients had advanced hepatic fibrosis, and 47 had hemochromatosis arthritis. Arthritis was significantly associated with the presence of advanced hepatic fibrosis as determined by liver biopsy (sensitivity, 84%, [95% CI, 62% to 95%]; negative predictive value, 95% [95% CI, 87% to 99%]; relative risk, 7.4 [95% CI, 2.5 to 23]; P<.001), APRI (sensitivity, 75% [95% CI, 55% to 88%]; negative predictive value, 91% [95% CI, 81% to 96%]; relative risk, 4.5 [95% CI, 2.0 to 10.2]; P<.001), or FIB4 (sensitivity, 61% [95% CI, 41% to 78%]; negative predictive value, 67% [95% CI, 68% to 90%]; relative risk, 2.2 [95% CI, 1.1 to 4.6]; P=.03). Mean cell volume values were significantly higher pretreatment in patients with F3-4 fibrosis (96.7±1.1 fL) compared with F0-2 fibrosis (93.4±0.5 fL; P=.004) and declined following treatment (F3-4, 93.2±0.9 fL, P=.01; F0-2, 91.7±0.6 fL, P=.01).

CONCLUSION

Advanced hepatic fibrosis is strongly associated with arthritis in HFE hemochromatosis. The absence of arthritis predicts a low likelihood of advanced hepatic fibrosis, supporting its use as a clinical marker for advanced hepatic fibrosis in HFE hemochromatosis.

EASL Clinical Practice Guidelines on haemochromatosis

Haemochromatosis is characterised by elevated transferrin saturation (TSAT) and progressive iron loading that mainly affects the liver. Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications. In patients homozygous for p.Cys282Tyr in HFE, provisional iron overload based on serum iron parameters (TSAT >45% and ferritin >200 μg/L in females and TSAT >50% and ferritin >300 μg/L in males and postmenopausal women) is sufficient to diagnose haemochromatosis. In patients with high TSAT and elevated ferritin but other HFE genotypes, diagnosis requires the presence of hepatic iron overload on MRI or liver biopsy. The stage of liver fibrosis and other end-organ damage should be carefully assessed at diagnosis because they determine disease management. Patients with advanced fibrosis should be included in a screening programme for hepatocellular carcinoma. Treatment targets for phlebotomy are ferritin <50 μg/L during the induction phase and <100 μg/L during the maintenance phase.

NTBI levels in C282Y homozygotes after therapeutic phlebotomy

C282Y homozygotes exposed to sustained elevated transferrin saturation (TS) may develop worsening clinical symptoms. This might be related to the appearance of non‐transferrin bound iron (NTBI) when TS≥50% and labile plasma iron (LPI) when TS levels reach 75–80%. In this study, NTBI levels were examined in 219 randomly selected untreated and treated C282Y homozygotes. Overall, 161 of 219 had TS ≥ 50%, 124 of whom had detectable NTBI (≥0.47 µM, 1.81 µM [0.92–2.46 µM]) with a median serum ferritin 320 µg/L (226–442 µg/L). Ninety of 219 homozygotes had TS ≥ 75%, and all had detectable NTBI (2.21 µM [1.53–2.59 µM] with a median ferritin 338 µg/L [230–447 µg/L]). Of 125 homozygotes who last had phlebotomy ≥12 months ago (42 months [25–74 months], 92 had TS levels ≥ 50%, and 70 of these had NTBI ≥ 0.47 µM (2.06 µM [1.23–2.61µM]). Twenty‐six of these 70 had a normal ferritin. Fifty‐five of 125 had TS ≥ 75%, and NTBI was detected in all of these (2.32 µM [1.57–2.77 µM]) with a median ferritin 344 µg/L (255–418 µg/L). Eighteen of these 55 had a normal ferritin. In summary, NTBI is frequently found in C282Y homozygotes with TS ≥ 50%. Furthermore, C282Y homozygotes in the maintenance phase often have TS ≥ 50% together with a normal ferritin. Therefore, monitoring the TS level during the maintenance phase is recommended as an accessible clinical marker of the presence of NTBI.

Patients with hereditary hemochromatosis reach safe range of transferrin saturation sooner with erythrocytaphereses than with phlebotomies

Introduction

For the maintenance treatment of patients with hereditary hemochromatosis (HH), it is advised to keep the transferrin saturation (TSAT) <70% to prevent formation of non‐transferrin‐bound iron and labile plasma iron. The period of the initial iron depletion may last up to 1 year or longer and during this period, the patient is exposed to elevated TSAT levels. Therapeutic erythrocytapheresis (TE) is a modality which has proven to reduce treatment duration of patients with iron overload from HH. In this study, we investigated the time to reach TSAT <70% for both treatment modalities.

Methods

From a previous randomized controlled trial comparing erythrocytaphereses with phlebotomies (PBMs), we performed an analysis in a subgroup of patients who presented with TSAT >70%. Mann‐Whitney U tests were performed to compare the number of treatments and the number of weeks to reach the interim goal of a persistent level of <70% for TSAT between TE and PBM.

Results

The period to reach TSAT levels of <70% was statistically significant shorter for the TE group compared to the PBM treatment group (median treatment procedures [IQR] 2.0 (5) vs 16.0 (23), P‐value: <.001, and median treatment duration [IQR]: 5.5 (11) vs 19.0 (29) weeks, P‐value: .007).

Conclusion

Patients with HH reach a safe TSAT <70% significantly sooner and with less treatment procedures with TE compared to PBM.

HFE hemochromatosis: an overview about therapeutic recommendations

Hemochromatosis is currently characterized by the iron overload caused by hepcidin deficiency. Large advances in the knowledge on the hemochromatosis pathophysiology have occurred due to a better understanding of the protein of the iron metabolism, the genetic basis of hemochromatosis and of other iron overload diseases or conditions which can lead to this phenotype. In the present review, the main aims are to show updates on hemochromatosis and to report a practical set of therapeutic recommendations for the human factors engineering protein (HFE) hemochromatosis for the p.Cys282Tyr (C282Y/C282Y) homozygous genotype, elaborated by the Haemochromatosis International Taskforce.

A survey of lifestyle habits, physician counseling, and direct-to consumer genetic testing in patients with hereditary hemochromatosis

INTRODUCTION AND OBJECTIVES

The goal of this study was to assess lifestyle habits and physician counseling of patients with hereditary hemochromatosis (HH), and determine the prevalence of direct-to-consumer (DTC) genetic testing.

MATERIALS AND METHODS

A 52-question survey was created to collect information on lifestyle habits and physician counseling among patients with HH, and the use of DTC genetic testing of patients referred to a clinic for evaluation of HH. A multivariate logistic regression model was applied to identify predictors of DTC genetic testing use.

RESULTS

The survey was e-mailed to 379 patients, of which 101 responded (26.6%). Among patients with HH, 37% reported alcohol use more than once weekly and 50% reported red meat consumption. The use of a vitamin C supplement was reported by 38.9% of participants. Among patients with living children and siblings, physicians failed to recommend HH screening 15.3% and 21.2% of the time respectively. Thirty-one patients reported DTC genetic testing, of which 46.7% (14/31) reported their DTC genetic test screened for HH. Six (19%) of those patients were prompted to see a specialist in HH based on the results.

CONCLUSIONS

Among patients with HH, lifestyle habits that may impact iron stores are common, but not all receive appropriate counseling. Direct-to-consumer genetic testing is common, and physicians should be aware of its limitations when patients seek further evaluation for HH based on their test results.

Genetic iron overload disorders

Due to its pivotal role in orchestrating vital cellular functions and metabolic processes, iron is an essential component of the human body and a main micronutrient in the human diet. However, excess iron causes an increased production of reactive oxygen species leading to cell dysfunction or death, tissue damage and organ disease. Iron overload disorders encompass a wide spectrum of pathological conditions of hereditary or acquired origin. A number of 'iron genes' have been identified as being associated with hereditary iron overload syndromes, the most common of which is hemochromatosis. Although linked to at least five different genes, hemochromatosis is recognized as a unique syndromic entity based on a common pathogenetic mechanism leading to excessive entry of unneeded iron into the bloodstream. In this review, we focus on the pathophysiologic basis and clinical aspects of the most common genetic iron overload syndromes in humans.

What's Important and New in Hemochromatosis?

Major advances in the understanding of genetic iron overload have led to a clarification of the nosology and terminology of the related diseases. The term hemochromatosis should be reserved to the entities where iron overload is related to hepcidin deficiency or hepcidin resistance. The diagnosis of hemochromatosis is non-invasive, based on clinical examination, blood investigations and, whenever possible, magnetic resonance imaging. Phlebotomies remain the mainstay of the treatment, but new therapeutic approaches should, in the future, constitute a valuable advance, hopefully both as an adjunct to bleeding in the induction phase and as its replacement in the maintenance phase. The goal of the present review is to update the terminology of hemochromatosis in light of major pathophysiological advances, and the main features of its diagnostic and therapeutic approaches.

Impaired Bone Microarchitecture in Patients with Hereditary Hemochromatosis and Skeletal Complications

Hereditary hemochromatosis (HHC) is characterized by excessive intestinal iron absorption resulting in a pathological increase of iron levels. Parenchyma damage may be a consequence of iron deposition in affected organs (e.g., liver, pancreas, gonads) as well as bones and joints, leading to osteoporosis with increased fracture risk and arthropathy. Up to date, it is not known whether HHC can also be considered as a risk factor for osteonecrosis. Likewise, the underlying skeletal changes are unknown regarding, e.g., microstructural properties of bone. We aimed to study the spectrum of skeletal complications in HHC and the possible underlying microarchitectural changes. Therefore, we retrospectively analyzed all patients with HHC (n = 10) presenting in our outpatient clinic for bone diseases. In addition to dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT) was performed and bone turnover markers, 25-OH-D3, ferritin and transferrin saturation were measured. Cortical volumetric bone mineral density (Ct.BMD) and cortical thickness (Ct.Th) were reduced, whereas trabecular microstructure (Tb.Th) and volumetric bone mineral density (Tb.BMD) were preserved compared to age- and gender-adjusted reference values from the literature. Interestingly, the occurrence of bone complications was age dependent; while younger patients presented with osteonecroses or transient bone marrow edema, patients older than 65 years presented with fractures. Our study provides first insights into altered bone microarchitecture in HHC and sheds new light on the occurrence of osteonecrosis. If available, HR-pQCT is a useful complement to fracture risk assessment and to determine microstructural deterioration and volumetric bone mineralization deficits.

Iron as a Therapeutic Target in HFE-Related Hemochromatosis: Usual and Novel Aspects

Genetic hemochromatosis is an iron overload disease that is mainly related to the C282Y mutation in the HFE gene. This gene controls the expression of hepcidin, a peptide secreted in plasma by the liver and regulates systemic iron distribution. Homozygous C282Y mutation induces hepcidin deficiency, leading to increased circulating transferrin saturation, and ultimately, iron accumulation in organs such as the liver, pancreas, heart, and bone. Iron in excess may induce or favor the development of complications such as cirrhosis, liver cancer, diabetes, heart failure, hypogonadism, but also complaints such as asthenia and disabling arthritis. Iron depletive treatment mainly consists of venesections that permit the removal of iron contained in red blood cells and the subsequent mobilization of stored iron in order to synthesize hemoglobin for new erythrocytes. It is highly efficient in removing excess iron and preventing most of the complications associated with excess iron in the body. However, this treatment does not target the biological mechanisms involved in the iron metabolism disturbance. New treatments based on the increase of hepcidin levels, by using hepcidin mimetics or inducers, or inhibitors of the iron export activity of ferroportin protein that is the target of hepcidin, if devoid of significant secondary effects, should be useful to better control iron parameters and symptoms, such as arthritis.

Haemochromatosis

Haemochromatosis is defined as systemic iron overload of genetic origin, caused by a reduction in the concentration of the iron regulatory hormone hepcidin, or a reduction in hepcidin-ferroportin binding. Hepcidin regulates the activity of ferroportin, which is the only identified cellular iron exporter. The most common form of haemochromatosis is due to homozygous mutations (specifically, the C282Y mutation) in HFE, which encodes hereditary haemochromatosis protein. Non-HFE forms of haemochromatosis due to mutations in HAMP, HJV or TFR2 are much rarer. Mutations in SLC40A1 (also known as FPN1; encoding ferroportin) that prevent hepcidin-ferroportin binding also cause haemochromatosis. Cellular iron excess in HFE and non-HFE forms of haemochromatosis is caused by increased concentrations of plasma iron, which can lead to the accumulation of iron in parenchymal cells, particularly hepatocytes, pancreatic cells and cardiomyocytes. Diagnosis is noninvasive and includes clinical examination, assessment of plasma iron parameters, imaging and genetic testing. The mainstay therapy is phlebotomy, although iron chelation can be used in some patients. Hepcidin supplementation might be an innovative future approach.