Guidelines for treating iron overload in myelodysplastic syndromes: a Taiwan consensus statement

Iron overload is common in myelodysplastic syndrome (MDS) patients, and an accumulation of evidence shows that iron chelation may have benefits in these patients. However, discussion and consensus about iron chelation therapy (ICT) for MDS patients is lacking in Taiwan and other Southeast Asian countries. An Expert Panel in Taiwan was organized in 2011 to develop iron overload guidelines and provide a uniform reference for physicians treating MDS patients with iron overload, with specific regard to when to initiate ICT, in which patients, and the clinical and scientific rationale behind its use.     

Overall survival in lower IPSS risk MDS by receipt of iron chelation therapy,adjusting for patient‐related factors and measuring from time of first red blood cell transfusion dependence: an MDS‐CAN analysis

Analyses suggest iron overload in red blood cell (RBC) transfusion‐dependent (TD) patients with myleodysplastic syndrome (MDS) portends inferior overall survival (OS) that is attenuated by iron chelation therapy (ICT) but may be biassed by unbalanced patient‐related factors. The Canadian MDS Registry prospectively measures frailty, comorbidity and disability. We analysed OS by receipt of ICT, adjusting for these patient‐related factors. TD International Prognostic Scoring System (IPSS) low and intermediate‐1 risk MDS, at RBC TD, were included. Predictive factors for OS were determined. A matched pair analysis considering age, revised IPSS, TD severity, time from MDS diagnosis to TD, and receipt of disease‐modifying agents was conducted. Of 239 patients, 83 received ICT; frailty, comorbidity and disability did not differ from non‐ICT patients. Median OS from TD was superior in ICT patients (5·2 vs. 2·1 years; P < 0·0001). By multivariate analysis, not receiving ICT independently predicted inferior OS, (hazard ratio for death 2·0, P = 0·03). In matched pair analysis, OS remained superior for ICT patients (P = 0·02). In this prospective, non‐randomized analysis, receiving ICT was associated with superior OS in lower IPSS risk MDS, adjusting for age, frailty, comorbidity, disability, revised IPSS, TD severity, time to TD and receiving disease‐modifying agents. This provides additional evidence that ICT may confer clinical benefit.     

Iron Chelation Therapy for Patients with Myelodysplastic Syndrome

Chronic blood transfusions are necessary for patients with hereditary anemia such as thalassemia, and for patients with myelodysplastic syndrome (MDS) who become anemic and transfusion-dependent. A common consequence of chronic transfusion is iron accumulation that can lead to organ damage. While there is general agreement regarding the value of iron chelation therapy to reduce the detrimental effects of iron overload in thalassemia major, the same is not true for MDS. The malignant nature of the disease and the relatively high cost of iron chelation therapy make cost-effectiveness an issue of great concern. Furthermore, the positive assessment of a drug's cost-effectiveness in one country does not necessarily justify its use in another country. More prospective studies are needed to identify the best iron chelator for patients with MDS as well as to identify those patients who will benefit most from iron chelation therapy.     

Patients with biochemical iron overload: causes and characteristics of a cohort of 150 cases

Biochemical iron overload (IO) is a frequent metabolic abnormality. It may be caused by several diseases, and data regarding the relative frequency of these are scant. A single diagnostic protocol including clinical, biochemical, and genetic data was used to diagnose the cause of biochemical IO in a group of 150 patients referred by general practitioners. Severe alterations of the HFE gene (42 patients, 28%), hepatitis C virus infection (33 patients, 22%), and dysmetabolic syndrome with iron overload (DSIO) (22 patients, 15%) emerged as the main causes, and other single causes were found in 20 patients (13%). In 19 patients (13%), multiple causes of IO were found, and in 14 patients no cause was found, 5 of whom had classical criteria of genetic hemochromatosis (GH) without HFE mutations. Transferrin saturation index (TSI) had a very low positive predictive value (0.16) for GH among patients with biochemical IO in this setting. In conclusion, 90% of patients with biochemical IO were diagnosed with a specific disorder. GH, hepatitis C infection, and DSIO were the major causes, and a large group of patients had multiple causes of IO. TSI is not a useful indicator of GH in patients referred by general practitioners.     

Iron overload and chelation therapy in patients with low-risk myelodysplastic syndromes with transfusion requirements

The main objective of the study was to analyze the incidence of iron overload (IO) and its management in transfusion-dependent patients with low-risk myelodysplastic syndrome (MDS) before the license of deferasirox. This observational, cross-sectional, and multicenter study was conducted from January to May 2007 in 81 Spanish hospitals. Eligible patients had a low or intermediate-1 risk score and had to have received at least ten units of packed red blood cell (PRBC). Of the 549 patients analyzed, 75% had received more than 20 PRBC units since diagnosis; 14% had IO at diagnosis and 58% at last follow-up. Thirty-eight percent of patients received chelation therapy; of those, 92% were treated with desferrioxamine. Ferritin levels at the start of chelation therapy were higher than 1,000 μg/L in 76% and over 2,500 μg/L in 24% of patients. Of the 202 patients who received some form of chelation therapy, ferritin levels increased from a mean ± SD of 1,986 ± 1,398 to 2,480 ± 1,648 μg/L at last follow-up in 86% (p < 0.001). In the remaining 29 patients treated with a minimally effective therapy, ferritin levels did not increase. Of these, only 11 patients received such therapy lasting more than 12 months. In conclusion, most low-risk transfusion-dependent MDS patients develop IO, but only a minority receives a minimally effective and timely iron chelation therapy.     

Deferasirox treatment improved the hemoglobin level and decreased transfusion requirements in four patients with the myelodysplastic syndrome and primary myelofibrosis

Transfusion-induced iron overload is a frequent problem that clinicians have to face in the treatment of patients affected by both myelodysplastic syndrome (MDS) and primary myelofibrosis (PMF). Different options are currently available for chelation therapy, e.g. oral once-daily administration of the iron chelator deferasirox. In 3 patients with MDS and 1 patient with PMF, deferasirox therapy resulted in an improvement in the hemoglobin level and a reduction in transfusion dependence. Our data open new insights regarding the benefit of iron chelation therapy not only for transfusional iron overload of myelodysplastic and myelofibrotic patients but also for the increase in hemoglobin levels. The biological mechanism of action of deferasirox, an effect which is not shared by other iron chelators, is still obscure and requires further investigations.     

Recent advances in the understanding of iron overload in sideroblastic myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal haematopoietic stem cell malignancies. A subgroup, the so‐called sideroblastic MDS, shows ring sideroblasts in the bone marrow aspirate that represent mitochondrial iron accumulation. Patients with sideroblastic MDS also develop systemic iron overload and generally have a low‐risk MDS. Therefore it is important to understand the mechanisms responsible for iron accumulation and the associated toxicity in these patients. Recently, low levels of the iron‐regulatory peptide hepcidin were found to contribute to body iron overload in β‐thalassaemia patients. A similar mechanism may account for systemic iron accumulation in sideroblastic MDS. Mitochondrial iron accumulation is observed in several subtypes of MDS, and predominantly in refractory anaemia with ring sideroblasts. The presence of ring sideroblasts is also the diagnostic hallmark in patients with inherited forms of sideroblastic anaemia. The ever‐increasing insights into the affected pathways in inherited sideroblastic anaemia may lead to a better comprehension of the pathogenesis of mitochondrial iron accumulation in MDS patients. Overall, an improved understanding of the mechanisms responsible for iron overload in MDS will lead to novel treatment strategies to reduce both systemic and mitochondrial iron overload, resulting in less tissue damage and more effective erythropoiesis.     

Controversies surrounding iron chelation therapy for MDS

The myelodysplastic syndromes (MDS) are characterized by cytopenias and acute myeloid leukemia risk. Most MDS patients eventually require transfusion of red blood cells for anemia, placing them at risk of iron overload (IOL). In beta-thalassemia major, transfusional IOL leads to organ dysfunction and death, however, with iron chelation therapy survival improved to near normal and organ function was improved. In lower risk MDS, several non-randomized studies suggest an adverse effect of IOL on survival, and that lowering iron minimizes this impact and may improve organ function. While guidelines for MDS generally recommend chelation in selected lower risk patients, data are emerging suggesting IOL may impact adversely on the outcome of higher risk MDS and stem cell transplantation (SCT) and that lowering iron may be beneficial in these patients. Trials to determine whether these effects are truly from lowering iron are currently enrolling. Chelation is costly and potentially toxic, and in MDS should be initiated after weighing potential risks and benefits for each patient until more definitive data are available. In this paper, data on the impact of IOL in MDS and SCT, possible mechanisms of iron toxicity such as oxidative stress, and the impact of lowering iron on organ function and survival are reviewed.     

Deferasirox chelation therapy in patients with transfusion‐dependent MDS: a ‘real‐world’ report from two regional Italian registries: Gruppo Romano Mielodisplasie and Registro Basilicata

Deferasirox (DFX) is an orally administered iron chelator approved for use in patients with transfusion‐dependent iron overload due to myelodysplastic syndromes (MDS). The safety and efficacy of DFX has been explored in clinical trial settings, but there is little data on unselected patients with MDS. The aim of this study was to retrospectively evaluate the safety, compliance, efficacy and effect on haematopoiesis of DFX in a large ‘real‐world’ MDS population. One hundred and eighteen patients with transfusion‐dependent MDS were treated with DFX across 11 centres in Italy. Serum ferritin levels, haematological response, dosing, adverse events and transfusion dependence were recorded at baseline, 3, 6, 12 and 24 months following initiation of treatment. DFX reduced mean serum ferritin levels from 1790 to 1140 ng/mL (P < 0.001), with 7.1% of patients achieving transfusion independence. Significant haematological improvement was seen in erythroid (17.6%), platelet (5.9%) and neutrophil counts (7.1%). Adverse events were reported in 47.5% of patients, including gastrointestinal and renal toxicity. Regression analysis showed that higher starting doses of DFX are associated with transfusion independence at 24 months. DFX is a safe, effective treatment for transfusion‐dependent MDS that can lead to transfusion independence and haematological improvement in a subset of patients.     

Myelodysplastic patients with raised percentage of hypochromic red cells have evidence of functional iron deficiency

Raised percentage hypochromic red cells (%HRC) were detected at diagnosis in 10 of 34 consecutive patients with low-risk myelodysplastic syndrome (MDS) [refractory anemia (RA) (4/26) and RA with ring sideroblasts (6/8)], all of whom had normal or increased serum ferritin and bone marrow iron stores. Elevated %HRC has persisted in all 10 cases and subsequently developed in another RA patient who later had a complete remission of MDS with normalisation of %HRC after a respiratory tract infection. A strong positive correlation was found between %HRC and erythrocyte zinc protoporphyrin levels in 11 MDS patients tested (p=0.01), suggesting that functional iron deficiency contributes to ineffective erythropoiesis in cases of MDS with raised %HRC. Five of seven patients with elevated %HRC had satisfactory haemoglobin responses to a trial of human recombinant erythropoietin without iron supplementation.     

No evidence for myocardial iron overload and free iron species in multitransfused patients with sickle/β0‐thalassaemia

Iron overload (IO) in the heart is a life‐threatening complication in transfusion‐dependent patients with thalassaemia major (TM) and to a lesser extent in sickle cell disease (SCD), while no data are available in patients with sickle/β⁰‐thalassaemia. Iron deposition in the heart, liver and pancreas was assessed using T2* MRI sequences, as well as free iron species assays – non‐transferrin bound iron (NTBI) and labile plasma iron (LPI), in addition to serum ferritin, percentage transferrin saturation and serum hepcidin, in 10 multitransfused patients (>30 yr) with sickle/β⁰‐thalassaemia. None of the patients had iron deposition in the heart. Three patients had mild, one had moderate, and two had severe liver IO. Two patients had mild iron deposition in the pancreas. In all the patients, serum hepcidin levels were normal – NTBI and LPI were not detected. Possible explanations of these findings are discussed.     

Labile plasma iron,more practical and more sensitive to iron overload in myelodysplastic syndromes

Objectives: In order to gain an insight into labile plasma iron (LPI) in iron metabolism microenvironment in MDS.

Methods: We performed ELISA, quantitative real-time polymerase chain reaction, flow cytometry, MRI T2* assays to test LPI, iron biochemical parameters, and liver iron concentration (LIC) among 22 MDS patients.

Results: LPI has a statistical difference (P?P?=?0.086 by ANOVA). After DFO treatment, serum hepcidin expression increased from 301.26?±?59.78 to 340.33?±?49.78?µg/l (P?=?0.032), while hepcidin/ASF was upregulated gradually from 0.16?±?0.08 to 0.22?±?0.03 (P?=?0.045). APAF-1 expression (P?=?0.047) and erythroid apoptosis rate (P?=?0.009) decreased significantly, respectively. No statistical difference was found in EPO (P?=?0.247) and GDF15 expression (P?=?0.172). LIC dropped from 9.83?±?4.84 to 6.28?±?4.01?mg/g dry weight (P?P?=?0.594). LPI has a closer connection to LIC than ASF (r?=?0.739, P?r?=?0.321, P?=?0.034).

Discussion: LPI seems to be a real-time indicator which reflects body iron loading status instantaneously. Despite the limited knowledge available on LPI speciation in different types and degrees of IO, LPI measurements can be and are in fact used for identifying systemic IO and for initiating/adjusting chelation regimens.     

Efficacy and safety of deferasirox in myelodysplastic syndromes

Transfusion dependence in myelodysplastic syndrome (MDS) patients may lead to organ damage due to accumulation of non-transferrin-bound iron with consequent increased oxidative stress. Iron chelation has been reported in retrospective studies to improve overall survival in low-risk MDS patients, but this information needs to be validated in prospective trials. The oral iron chelator, deferasirox, has been shown to reduce serum ferritin levels in chelation naïve and pre-treated patients and to reduce labile plasma iron, independently from the efficacy on iron overload. Deferasirox is a potent NF-kB inhibitor, tested in vivo and on acute myeloid leukemia and MDS cell lines, and this effect may explain in part the phenomenon of hematological improvements reported in case reports and in different clinical trials. The drug has an acceptable safety profile, with the most common side effects reported being non-progressive change in serum creatinine level, gastrointestinal disturbances, and skin rash. In this review, we report the results of different studies testing safety and efficacy of deferasirox in MDS patients, side effects associated with the drug, and suggested management of iron overload.     

No evidence for myocardial iron overload in multitransfused patients with myelodysplastic syndrome using cardiac magnetic resonance T2 technique

The method of cardiovascular T2 magnetic resonance imaging (MRI) allows in vivo estimation of iron in the heart and liver and was used to measure the degree of iron overload in 10 transfused MDS patients (average 90 blood units) and in 3 patients with congenital hemolytic anemia. In all MDS patients iron overload was found in the liver but not in the heart. Patients with congenital anemias had iron in both organs despite iron chelation. It is possible that in MDS more time and more transfusions are required to induce iron accumulation in the myocardium. Therefore, cardiac MRI may serve as a diagnostic tool to assess if and when iron chelation is indicated.     

Current therapeutic approaches for patients with myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a heterogeneous spectrum of disorders requiring selective therapy based on patients’ specific clinical features, predominantly their prognostic subgroups, age and performance status. Guidelines for management of patients with MDS have been generated by a number of national panels. This review focuses on evidence‐based data supporting therapeutic approaches, which have also been recommended by the US National Comprehensive Cancer Network MDS Panel, with discussion of accessibility of recommended drugs in the US and in other countries. For lower risk disease (International Prognostic Scoring System Low and Intermediate‐1) therapy is aimed at haematological improvement whereas for higher risk disease (Intermediate‐2 and High) treatment focuses on altering disease natural history. Recent information regarding additional clinical and biological features has provided useful parameters for assessing disease prognosis that aid risk‐based management decisions. The rationale for use of low versus high intensity therapies with these agents, including allogeneic haematopoietic stem cell transplantation, is discussed in detail.     

Evidence- and consensus-based practice guidelines for the therapy of primary myelodysplastic syndromes. A statement from the Italian Society of Hematology

BACKGROUND AND OBJECTIVES: Novel therapeutic agents and strategies have been introduced into the management of myelodysplastic syndromes (MDS) in the last years. This has led to more treatment options and a better chance of long-term survival for MDS patients, but also to uncertainty regarding the optimal use and possible side effects of these treatments. The Italian Society of Hematology commissioned a project to develop guidelines for the therapy of MDS using evidence-based knowledge and consensus-formation techniques. DESIGN AND METHODS: An Advisory Council (AC) shaped the project around a series of key clinical questions, performed a systematic search for evidence and graded the available evidence according to the Scottish Intercollegiate Guidelines Network (SIGN). A list of clinical questions was mailed to each of 10 senior hematologists composing the Expert Panel (EP): the panelists were asked to rank the most relevant questions, and to formulate answers to the questions according to the tables of evidence. A scenario phase followed, so as to reach a consensus on the three top ranked questions. The EP was asked to score patient profiles as appropriate or not appropriate for the therapeutic strategy under scrutiny, according to the RAND technique. Finally, from September 2001 to January 2002, four Consensus Conferences conducted according to the Nominal Group Technique were held in Milan, Italy. The overall goal of the conferences was to take a final decision upon the appropriateness of the uncertain scenarios and of the uncertain responses to the clinical questions. RESULTS: Evidence was judged sufficient for providing recommendations on the use of allogeneic stem cell transplantation, leukemia-like chemotherapy, autologous stem cell transplantation, low-dose chemotherapy, danazol, immunosuppressive therapy, hypomethylating agents and hematopoietic growth factors. Specific recommendations for supportive therapy, including iron chelation, were issued. Allogeneic stem cell transplantation was unanimously considered as the only curative treatment for MDS patients, and recommendations on its use were agreed based on patient's age, risk, clinical features and donor availability. AML-like chemotherapy was also considered a valuable therapeutic option for subsets of MDS patients. Autologous stem cell transplantation was recommended for patients who lack an HLA identical donor and have achieved complete remission with AML-like chemotherapy. Decitabine, recombinant human erythropoietin and immunosuppressive therapy were judged valuable therapeutic options for subsets of MDS patients whereas low-dose cytarabine was not.Specific therapeutic strategies for those subjects younger than 18 years or older than 75 years and the strategy of watchful waiting were decided by patient-oriented questions. INTERPRETATION AND CONCLUSIONS: Using evidence and consensus, recommendations for the treatment of MDS were issued. Statements were graded according to the strength of the supporting evidence and uncertainty was explicitly declared.     

Relative response of patients with myelodysplastic syndromes and other transfusion-dependent anaemias to deferasirox (ICL670): a 1-yr prospective study

Objectives/methods:  This 1-yr prospective phase II trial evaluated the efficacy of deferasirox in regularly transfused patients aged 3–81 yrs with myelodysplastic syndromes (MDS; n  = 47), Diamond–Blackfan anaemia (DBA; n  = 30), other rare anaemias ( n  = 22) or β-thalassaemia ( n  = 85). Dosage was determined by baseline liver iron concentration (LIC).
Results:  In patients with baseline LIC ≥7 mg Fe/g dry weight, deferasirox initiated at 20 or 30 mg/kg/d produced statistically significant decreases in LIC ( P  < 0.001); these decreases were greatest in MDS and least in DBA. As chelation efficiency and iron excretion did not differ significantly between disease groups, the differences in LIC changes are consistent with mean transfusional iron intake (least in MDS: 0.28 ± 0.14 mg/kg/d; greatest in DBA: 0.4 ± 0.11 mg/kg/d). Overall, LIC changes were dependent on dose ( P  < 0.001) and transfusional iron intake ( P  < 0.01), but not statistically different between disease groups. Changes in serum ferritin and LIC were correlated irrespective of disease group ( r  = 0.59), supporting the potential use of serum ferritin for monitoring deferasirox therapy. Deferasirox had a safety profile compatible with long-term use. There were no disease-specific safety/tolerability effects: the most common adverse events were gastrointestinal disturbances, skin rash and non-progressive serum creatinine increases.
Conclusions:  Deferasirox is effective for reducing iron burden with a defined, clinically manageable safety profile in patients with various transfusion-dependent anaemias. There were no disease-specific adverse events. Once differences in transfusional iron intake are accounted for, dose-dependent changes in LIC or serum ferritin are similar in MDS and other disease groups.     

Deferasirox in MDS patients with transfusion-caused iron overload—a phase-II study

Blood transfusions represent a main component of supportive care in myelodysplastic syndromes (MDS). To avoid organ damage caused by transfusion-dependent iron overload, an adequate iron chelation therapy is required. Recently, a new oral iron chelator deferasirox (ICL670, Exjade) has become available. A study was conducted to demonstrate the efficacy and tolerability of deferasirox in transfusion-dependent iron-overloaded patients with MDS. The efficacy of deferasirox was monitored by changes in serum ferritin, bone marrow iron, and liver iron concentration (LIC), as determined by T2*-weighted magnetic resonance imaging. Twelve patients with MDS of different subtypes (median age 76 years, range 53-91) were enrolled. Deferasirox administered in a once-daily dose of 20-30 mg/kg for 12 months was effective in reducing median ferritin concentration from 1,515 microg/L (range 665-6,900) to 413 microg/L (range 105-3,052). Within the first 4 weeks of treatment before the continuous decline of ferritin levels, the values markedly rose in eight of 12 patients. The median LIC declined from 315 to 230 micromol/g (p=0.02) at the end of study, accompanied by a reduction of bone marrow siderosis. The most common adverse events were mild and transient gastrointestinal disturbances, skin rash, nonprogressive transient increases in serum creatinine and urine beta2-microglobulin, and a temporary reduction of the creatinine clearance. The renal parameters normalized after end of treatment. No hematologic toxicities were observed. Deferasirox proved to be effective in transfusion-dependent iron overload in MDS by mobilizing iron deposits in liver and at least stabilizing iron stores in bone marrow.     

High incidence of hemochromatosis gene mutations in the myelodysplastic syndrome: the Budapest Study on 50 patients

Genotypic testing of nonselected patients with the myelodysplastic syndrome (MDS) for the C282Y and H63D mutations of the HFE gene responsible for hereditary hemochromatosis revealed a significantly increased frequency of these mutations when compared to healthy blood donors reflecting the average population. Among the 50 patients examined [26 refractory anemia (RA), 9 refractory anemia with ring sideroblasts (RARS), 2 refractory anemia with excess of blasts (RAEB) and 13 refractory anemia with excess of blasts in transformation (RAEB-t)] there were 24 heterozygotes (20 for H63D and 4 for C282Y), 1 homozygote for H63D and 1 compound heterozygote. The difference between the HFE-positive and HFE-negative MDS patients as regards initial serum iron and transferrin saturation was not significant. Inevitably the iron overload syndrome eventually develops in MDS patients due to intrinsic characteristics of the disease as well as an escalating need for blood transfusion therapy in the course of the disease. The high incidence rate of HFE gene mutations among MDS patients may also contribute to this vicious circle.     

Variable phenotypic presentation of iron overload in H63D homozygotes: are genetic modifiers the cause?

BACKGROUND: First considered as a polymorphism of the HFE gene, the H63D mutation is now widely recognised as a haemochromatosis associated allele. But few H63D homozygotes with clinical manifestations of hereditary haemochromatosis (HH) have been reported. Concurrently, an increasing number of genes have been shown to interact with HFE in iron metabolism. AIMS: To describe the clinical expression of iron overload (IO) associated with H63D homozygosity, and search for potential genetic modifiers (within the HFE or other genes) that could explain the variability of the phenotypes. PATIENTS AND METHODS: We retrospectively analysed the clinical phenotype of 56 H63D homozygotes referred for a personal or family history of IO. For each subject we examined intragenic HFE haplotypes and transferrin receptor (TfR) gene polymorphisms and searched for the Y250X mutation on the TFR2 gene. Additionally, we sequenced the HFE gene of H63D homozygotes with HH. RESULTS: Fifty of 56 subjects had biological and/or clinical abnormalities of iron metabolism. Up to two thirds of patients (n=34) had no acquired cause of IO. Among these, 12 had a phenotypic diagnosis of HH. In the iron loaded group there was a strong prevalence of male patients. No correlation was found between the potential genetic modifiers and phenotypes. No additional mutation of HFE was identified. CONCLUSION: The variable phenotypes associated with H63D homozygosity do not appear to be linked to other HFE mutations, to the TFR2 Y250X mutation, or to HFE or TfR gene intragenic polymorphisms. The exact role of H63D homozygosity in IO and HH needs to be further investigated in unselected populations.