Long term comparative studies in thalassemia patients treated with deferoxamine or a deferoxamine/deferiprone combination. Identification of effective chelation therapy protocols

Drug Selection and Posology, Optimal Therapies and Risk/Benefit Assessment in Medicine: The Paradigm of Iron-Chelating Drugs

The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.

Interventions for improving adherence to iron chelation therapy in people with sickle cell disease or thalassaemia

BACKGROUND

Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia are at risk of iron overload. Iron overload can lead to iron toxicity in vulnerable organs such as the heart, liver and endocrine glands, which can be prevented and treated with iron-chelating agents. The intensive demands and uncomfortable side effects of therapy can have a negative impact on daily activities and wellbeing, which may affect adherence.

OBJECTIVES

To identify and assess the effectiveness of different types of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions) and interventions specific to different age groups, to improve adherence to iron chelation therapy compared to another listed intervention, or standard care in people with SCD or thalassaemia.

SEARCH METHODS

We searched CENTRAL (Cochrane Library), MEDLINE, PubMed, Embase, CINAHL, PsycINFO, ProQuest Dissertations & Global Theses, Web of Science & Social Sciences Conference Proceedings Indexes and ongoing trial databases (13 December 2021). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register (1 August 2022).

SELECTION CRITERIA

For trials comparing medications or medication changes, only randomised controlled trials (RCTs) were eligible for inclusion. For studies including psychological and psychosocial interventions, educational interventions, or multi-component interventions, non-randomised studies of interventions (NRSIs), controlled before-after studies, and interrupted time series studies with adherence as a primary outcome were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

For this update, two authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 19 RCTs and one NRSI published between 1997 and 2021. One trial assessed medication management, one assessed an education intervention (NRSI) and 18 RCTs were of medication interventions. Medications assessed were subcutaneous deferoxamine, and two oral chelating agents, deferiprone and deferasirox. We rated the certainty of evidence as very low to low across all outcomes identified in this review. Four trials measured quality of life (QoL) with validated instruments, but provided no analysable data and reported no difference in QoL. We identified nine comparisons of interest. 1. Deferiprone versus deferoxamine We are uncertain whether or not deferiprone affects adherence to iron chelation therapy (four RCTs, unpooled, very low-certainty evidence), all-cause mortality (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.18 to 1.21; 3 RCTs, 376 participants; very low-certainty evidence), or serious adverse events (SAEs) (RR 1.43, 95% CI 0.83 to 2.46; 1 RCT, 228 participants; very low-certainty evidence).  Adherence was reported as "good", "high" or "excellent" by all seven trials, though the data could not be analysed formally: adherence ranged from 69% to 95% (deferiprone, mean 86.6%), and 71% to 93% (deferoxamine, mean 78.8%), based on five trials (474 participants) only. 2. Deferasirox versus deferoxamine We are uncertain whether or not deferasirox affects adherence to iron chelation therapy (three RCTs, unpooled, very low-certainty evidence), although medication adherence was high in all trials. We are uncertain whether or not there is any difference between the drug therapies in serious adverse events (SAEs) (SCD or thalassaemia) or all-cause mortality (thalassaemia). 3. Deferiprone versus deferasirox We are uncertain if there is a difference between oral deferiprone and deferasirox based on a single trial in children (average age 9 to 10 years) with any hereditary haemoglobinopathy in adherence, SAEs and all-cause mortality. 4. Deferasirox film-coated tablet (FCT) versus deferasirox dispersible tablet (DT) One RCT compared deferasirox in different tablet forms. There may be a preference for FCTs, shown through a trend for greater adherence (RR 1.10, 95% CI 0.99 to 1.22; 1 RCT, 88 participants), although medication adherence was high in both groups (FCT 92.9%; DT 85.3%). We are uncertain if there is a benefit in chelation-related AEs with FCTs. We are uncertain if there is a difference in the incidence of SAEs, all-cause mortality or sustained adherence. 5. Deferiprone and deferoxamine combined versus deferiprone alone We are uncertain if there is a difference in adherence, though reporting was usually narrative as triallists report it was "excellent" in both groups (three RCTs, unpooled). We are uncertain if there is a difference in the incidence of SAEs and all-cause mortality.  6. Deferiprone and deferoxamine combined versus deferoxamine alone We are uncertain if there is a difference in adherence (four RCTs), SAEs (none reported in the trial period) and all-cause mortality (no deaths reported in the trial period). There was high adherence in all trials. 7. Deferiprone and deferoxamine combined versus deferiprone and deferasirox combined There may be a difference in favour of deferiprone and deferasirox (combined) in rates of adherence (RR 0.84, 95% CI 0.72 to 0.99) (one RCT), although it was high (> 80%) in both groups. We are uncertain if there is a difference in SAEs, and no deaths were reported in the trial, so we cannot draw conclusions based on these data (one RCT). 8. Medication management versus standard care We are uncertain if there is a difference in QoL (one RCT), and we could not assess adherence due to a lack of reporting in the control group. 9. Education versus standard care One quasi-experimental (NRSI) study could not be analysed due to the severe baseline confounding.

AUTHORS' CONCLUSIONS

The medication comparisons included in this review had higher than average adherence rates not accounted for by differences in medication administration or side effects, though often follow-up was not good (high dropout over longer trials), with adherence based on a per protocol analysis. Participants may have been selected based on higher adherence to trial medications at baseline. Also, within the clinical trial context, there is increased attention and involvement of clinicians, thus high adherence rates may be an artefact of trial participation. Real-world, pragmatic trials in community and clinic settings are needed that examine both confirmed or unconfirmed adherence strategies that may increase adherence to iron chelation therapy. Due to lack of evidence this review cannot comment on intervention strategies for different age groups.

Deferiprone and Iron-Maltol: Forty Years since Their Discovery and Insights into Their Drug Design, Development, Clinical Use and Future Prospects

The historical insights and background of the discovery, development and clinical use of deferiprone (L1) and the maltol-iron complex, which were discovered over 40 years ago, highlight the difficulties, complexities and efforts in general orphan drug development programs originating from academic centers. Deferiprone is widely used for the removal of excess iron in the treatment of iron overload diseases, but also in many other diseases associated with iron toxicity, as well as the modulation of iron metabolism pathways. The maltol-iron complex is a recently approved drug used for increasing iron intake in the treatment of iron deficiency anemia, a condition affecting one-third to one-quarter of the world's population. Detailed insights into different aspects of drug development associated with L1 and the maltol-iron complex are revealed, including theoretical concepts of invention; drug discovery; new chemical synthesis; in vitro, in vivo and clinical screening; toxicology; pharmacology; and the optimization of dose protocols. The prospects of the application of these two drugs in many other diseases are discussed under the light of competing drugs from other academic and commercial centers and also different regulatory authorities. The underlying scientific and other strategies, as well as the many limitations in the present global scene of pharmaceuticals, are also highlighted, with an emphasis on the priorities for orphan drug and emergency medicine development, including the roles of the academic scientific community, pharmaceutical companies and patient organizations.

Serum Ferritin Levels and Other Associated Parameters with Diabetes Mellitus in Adult Patients Suffering from Beta Thalassemia Major

Background

Although beta thalassemia major (BTM) patients are properly treated with blood transfusions in accompany with iron chelation therapy, they suffer from complications, such as diabetes mellitus (DM).

Purpose

The purpose was to detect the critical serum ferritin level and other parameters correlated with DM among adult BTM patients. Also, it was to study whether each of these parameters is associated with a certain period of age.

Patients and Methods

This study included 200 adult BTM patients. A cross-sectional study was carried out. Patients clinical and laboratory variables, such as ferritin levels, and fasting blood glucose (FBS) were extracted from medical records at Zagazig University Hospital, Egypt. Liver and cardiac iron contents were assessed using MRI T2* methods. Statistical analysis was performed using IBM SPSS V26.0 software package.

Results

The overall frequency of DM over the total sample equals 6.5%. There were no impaired fasting glucose (IFG) in the medical records. Statistical significance between serum ferritin and DM was (P = 0.014). The serum ferritin 2500 ng/mL with age group (27-<32) years-old were risk factors. The distributions of DM according to BMI were (3.5%) of class overweight. Significant association between DM and BMI was (r = 0.357, P < 0.001). Liver MRI T2* has significant correlation with serum ferritin, but cardiac MRI T2* was poorly correlated. Association between liver and cardiac MRI T2* was not found.

Conclusion

Age group (27-<32) years-old and ferritin >2500 ng/mL should be properly treated immediately. The serum ferritin and BMI of class "overweight" were risk factors for DM. Factors such as diet should be followed. Serum ferritin can be used for estimating liver iron content for economic factors. But cardiac MRI T2* must be performed for evaluating cardiac iron accurately.

Iron Chelators in Treatment of Iron Overload

Patients suffering from iron overload can experience serious complications. In such patients, various organs, such as endocrine glands and liver, can be damaged. Although iron is a crucial element for life, iron overload can be potentially toxic for human cells due to its role in generating free radicals. In the past few decades, there has been a major improvement in the survival of patients who suffer from iron overload due to the application of iron chelation therapy in clinical practice. In clinical use, deferoxamine, deferiprone, and deferasirox are the three United States Food and Drug Administration-approved iron chelators. Each of these iron chelators is well known for the treatment of iron overload in various clinical conditions. Based on several up-to-date studies, this study explained iron overload and its clinical symptoms, introduced each of the above-mentioned iron chelators, and evaluated their advantages and disadvantages with an emphasis on combination therapy, which in recent studies seems a promising approach. In numerous clinical conditions, due to the lack of accurate indicators, choosing a standard approach for iron chelation therapy can be difficult; therefore, further studies on the issue are still required. This study aimed to introduce each of these iron chelators, combination therapy, usage doses, specific clinical applications, and their advantages, toxicity, and side effects.

Iron and Chelation in Biochemistry and Medicine: New Approaches to Controlling Iron Metabolism and Treating Related Diseases

Iron is essential for all living organisms. Many iron-containing proteins and metabolic pathways play a key role in almost all cellular and physiological functions. The diversity of the activity and function of iron and its associated pathologies is based on bond formation with adjacent ligands and the overall structure of the iron complex in proteins or with other biomolecules. The control of the metabolic pathways of iron absorption, utilization, recycling and excretion by iron-containing proteins ensures normal biologic and physiological activity. Abnormalities in iron-containing proteins, iron metabolic pathways and also other associated processes can lead to an array of diseases. These include iron deficiency, which affects more than a quarter of the world's population; hemoglobinopathies, which are the most common of the genetic disorders and idiopathic hemochromatosis. Iron is the most common catalyst of free radical production and oxidative stress which are implicated in tissue damage in most pathologic conditions, cancer initiation and progression, neurodegeneration and many other diseases. The interaction of iron and iron-containing proteins with dietary and xenobiotic molecules, including drugs, may affect iron metabolic and disease processes. Deferiprone, deferoxamine, deferasirox and other chelating drugs can offer therapeutic solutions for most diseases associated with iron metabolism including iron overload and deficiency, neurodegeneration and cancer, the detoxification of xenobiotic metals and most diseases associated with free radical pathology.

Single-center retrospective study of the effectiveness and toxicity of the oral iron chelating drugs deferiprone and deferasirox

BACKGROUND

Iron overload, resulting from blood transfusions in patients with chronic anemias, has historically been controlled with regular deferoxamine, but its parenteral requirement encouraged studies of orally-active agents, including deferasirox and deferiprone. Deferasirox, licensed by the US Food and Drug Administration in 2005 based upon the results of randomized controlled trials, is now first-line therapy worldwide. In contrast, early investigator-initiated trials of deferiprone were prematurely terminated after investigators raised safety concerns. The FDA declined market approval of deferiprone; years later, it licensed the drug as "last resort" therapy, to be prescribed only if first-line drugs had failed. We undertook to evaluate the long-term effectiveness and toxicities of deferiprone and deferasirox in one transfusion clinic.

METHODS AND FINDINGS

Under an IRB-approved study, we retrospectively inspected the electronic medical records of consented iron-loaded patients managed between 2009 and 2015 at The University Health Network (UHN), Toronto. We compared changes in liver and heart iron, adverse effects and other outcomes, in patients treated with deferiprone or deferasirox.

RESULTS

Although deferiprone was unlicensed in Canada, one-third (n = 41) of locally-transfused patients had been switched from first-line, licensed therapies (deferoxamine or deferasirox) to regimens of unlicensed deferiprone. The primary endpoint of monitoring in iron overload, hepatic iron concentration (HIC), increased (worsened) during deferiprone monotherapy (mean 10±2-18±2 mg/g; p < 0.0003), exceeding the threshold for life-threatening complications (15 mg iron/g liver) in 50% patients. During deferasirox monotherapy, mean HIC decreased (improved) (11±1-6±1 mg/g; p < 0.0001). Follow-up HICs were significantly different following deferiprone and deferasirox monotherapies (p < 0.0000002). Addition of low-dose deferoxamine (<40 mg/kg/day) to deferiprone did not result in reductions of HIC to <15 mg/g (baseline 20±4 mg/g; follow-up, 18±4 mg/g; p < 0.2) or in reduction in the proportion of patients with HIC exceeding 15 mg/g (p < 0.2). During deferiprone exposure, new diabetes mellitus, a recognized consequence of inadequate iron control, was diagnosed in 17% patients, most of whom had sustained HICs exceeding 15 mg/g for years; one woman died after 13 months of a regimen of deferiprone and low-dose deferasirox. During deferiprone exposure, serum ALT increased over baseline in 65% patients. Mean serum ALT increased 6.6-fold (p < 0.001) often persisting for years. During deferasirox exposure, mean ALT was unchanged (p < 0.84). No significant differences between treatment groups were observed in the proportions of patients estimated to have elevated cardiac iron.

CONCLUSIONS

Deferiprone showed ineffectiveness and significant toxicity in most patients. Combination with low doses of first-line therapies did not improve the effectiveness of deferiprone. Exposure to deferiprone, over six years while the drug was unlicensed, in the face of ineffectiveness and serious toxicities, demands review of the standards of local medical practice. The limited scope of regulatory approval of deferiprone, worldwide, should restrict its exposure to the few patients genuinely unable to tolerate the two effective, first-line therapies.

Interventions for improving adherence to iron chelation therapy in people with sickle cell disease or thalassaemia

BACKGROUND

Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia (who are transfusion-dependent or non-transfusion-dependent) are at risk of iron overload. Iron overload can lead to iron toxicity in vulnerable organs such as the heart, liver and endocrine glands; which can be prevented and treated with iron chelating agents. The intensive demands and uncomfortable side effects of therapy can have a negative impact on daily activities and well-being, which may affect adherence.

OBJECTIVES

To identify and assess the effectiveness of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions) to improve adherence to iron chelation therapy in people with SCD or thalassaemia.

SEARCH METHODS

We searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL, PsycINFO, Psychology and Behavioral Sciences Collection, Web of Science Science & Social Sciences Conference Proceedings Indexes and ongoing trial databases (01 February 2017). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register (12 December 2017).

SELECTION CRITERIA

For trials comparing medications or medication changes, only randomised controlled trials (RCTs) were eligible for inclusion.For studies including psychological and psychosocial interventions, educational Interventions, or multi-component interventions, non-RCTs, controlled before-after studies, and interrupted time series studies with adherence as a primary outcome were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial eligibility, risk of bias and extracted data. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

We included 16 RCTs (1525 participants) published between 1997 and 2017. Most participants had β-thalassaemia major; 195 had SCD and 88 had β-thalassaemia intermedia. Mean age ranged from 11 to 41 years. One trial was of medication management and 15 RCTs were of medication interventions. Medications assessed were subcutaneous deferoxamine, and two oral-chelating agents, deferiprone and deferasirox.We rated the quality of evidence as low to very low across all outcomes identified in this review.Three trials measured quality of life (QoL) with validated instruments, but provided no analysable data and reported no difference in QoL.Deferiprone versus deferoxamineWe are uncertain whether deferiprone increases adherence to iron chelation therapy (four trials, very low-quality evidence). Results could not be combined due to considerable heterogeneity (participants' age and different medication regimens). Medication adherence was high (deferiprone (85% to 94.9%); deferoxamine (71.6% to 93%)).We are uncertain whether deferiprone increases the risk of agranulocytosis, risk ratio (RR) 7.88 (99% confidence interval (CI) 0.18 to 352.39); or has any effect on all-cause mortality, RR 0.44 (95% CI 0.12 to 1.63) (one trial; 88 participants; very low-quality evidence).Deferasirox versus deferoxamineWe are uncertain whether deferasirox increases adherence to iron chelation therapy, mean difference (MD) -1.40 (95% CI -3.66 to 0.86) (one trial; 197 participants; very-low quality evidence). Medication adherence was high (deferasirox (99%); deferoxamine (100%)). We are uncertain whether deferasirox decreases the risk of thalassaemia-related serious adverse events (SAEs), RR 0.95 (95% CI 0.41 to 2.17); or all-cause mortality, RR 0.96 (95% CI 0.06 to 15.06) (two trials; 240 participants; very low-quality evidence).We are uncertain whether deferasirox decreases the risk of SCD-related pain crises, RR 1.05 (95% CI 0.68 to 1.62); or other SCD-related SAEs, RR 1.08 (95% CI 0.77 to 1.51) (one trial; 195 participants; very low-quality evidence).Deferasirox film-coated tablet (FCT) versus deferasirox dispersible tablet (DT)Deferasirox FCT may make little or no difference to adherence, RR 1.10 (95% CI 0.99 to 1.22) (one trial; 173 participants; low-quality evidence). Medication adherence was high (FCT (92.9%); DT (85.3%)).We are uncertain if deferasirox FCT increases the incidence of SAEs, RR 1.22 (95% CI 0.62 to 2.37); or all-cause mortality, RR 2.97 (95% CI 0.12 to 71.81) (one trial; 173 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferiprone alone We are uncertain if deferiprone and deferoxamine combined increases adherence to iron chelation therapy (very low-quality evidence). Medication adherence was high (deferiprone 92.7% (range 37% to 100%) to 93.6% (range 56% to 100%); deferoxamine 70.6% (range 25% to 100%).Combination therapy may make little or no difference to the risk of SAEs, RR 0.15 (95% CI 0.01 to 2.81) (one trial; 213 participants; low-quality evidence).We are uncertain if combination therapy decreases all-cause mortality, RR 0.77 (95% CI 0.18 to 3.35) (two trials; 237 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferoxamine aloneDeferiprone and deferoxamine combined may have little or no effect on adherence to iron chelation therapy (four trials; 216 participants; low-quality evidence). Medication adherence was high (deferoxamine 91.4% to 96.1%; deferiprone: 82.4%)Deferiprone and deferoxamine combined, may have little or no difference in SAEs or mortality (low-quality evidence). No SAEs occurred in three trials and were not reported in one trial. No deaths occurred in two trials and were not reported in two trials.Deferiprone and deferoxamine combined versus deferiprone and deferasirox combinedDeferiprone and deferasirox combined may improve adherence to iron chelation therapy, RR 0.84 (95% CI 0.72 to 0.99) (one trial; 96 participants; low-quality evidence). Medication adherence was high (deferiprone and deferoxamine: 80%; deferiprone and deferasirox: 95%).We are uncertain if deferiprone and deferasirox decreases the incidence of SAEs, RR 1.00 (95% CI 0.06 to 15.53) (one trial; 96 participants; very low-quality evidence).There were no deaths in the trial (low-quality evidence).Medication management versus standard careWe are uncertain if medication management improves health-related QoL (one trial; 48 participants; very low-quality evidence). Adherence was only measured in one arm of the trial.

AUTHORS' CONCLUSIONS

The medication comparisons included in this review had higher than average adherence rates not accounted for by differences in medication administration or side effects.Participants may have been selected based on higher adherence to trial medications at baseline. Also, within the clinical trial context, there is increased attention and involvement of clinicians, thus high adherence rates may be an artefact of trial participation.Real-world, pragmatic trials in community and clinic settings are needed that examine both confirmed or unconfirmed adherence strategies that may increase adherence to iron chelation therapy.Due to lack of evidence this review cannot comment on intervention strategies for different age groups.

Transplantation in patients with iron overload: is there a place for magnetic resonance imaging? : Transplantation in iron overload

In iron overload diseases (thalassemia, sickle cell, and myelodysplastic syndrome), iron is deposited in all internal organs, leading to functional abnormalities. Hematopoietic stem cell transplantation (HSCT) is the only treatment offering a potential cure in these diseases. Our aim was to describe the experience in the field and the role of magnetic resonance imaging in the evaluation of iron overload before and after HSCT. Magnetic resonance imaging (MRI), using T2*, is the most commonly used tool to diagnose myocardial-liver iron overload and guide tailored treatment. Currently, HSCT offers complete cure in thalassemia major, after overcoming the immunologic barrier, and should be considered for all patients who have a suitable donor. The overall thalassemia-free survival of low-risk, HLA-matched sibling stem cell transplantation patients is 85-90%, with a 95% overall survival. The problems of rejection and engraftment are improving with the use of adequate immunosuppression. However, a detailed iron assessment of both heart and liver is necessary for pre- and post-transplant evaluation. In iron overload diseases, heart and liver iron evaluation is indispensable not only for the patients' survival, but also for evaluation before and after HSCT.

Deferasirox for managing iron overload in people with thalassaemia

BACKGROUND

Thalassaemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusions. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone are effective; however, a review of the effectiveness and safety of the newer oral chelator deferasirox in people with thalassaemia is needed.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and iron overload.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 12 August 2016.We also searched MEDLINE, Embase, the Cochrane Library, Biosis Previews, Web of Science Core Collection and three trial registries: ClinicalTrials.gov; the WHO International Clinical Trials Registry Platform; and the Internet Portal of the German Clinical Trials Register: 06 and 07 August 2015.

SELECTION CRITERIA

Randomised controlled studies comparing deferasirox with no therapy or placebo or with another iron-chelating treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Sixteen studies involving 1807 randomised participants (range 23 to 586 participants) were included. Twelve two-arm studies compared deferasirox to placebo (two studies) or deferoxamine (seven studies) or deferiprone (one study) or the combination of deferasirox and deferoxamine to deferoxamine alone (one study). One study compared the combination of deferasirox and deferiprone to deferiprone in combination with deferoxamine. Three three-arm studies compared deferasirox to deferoxamine and deferiprone (two studies) or the combination of deferasirox and deferiprone to deferiprone and deferasirox monotherapy respectively (one study). One four-arm study compared two different doses of deferasirox to matching placebo groups.The two studies (a pharmacokinetic and a dose-escalation study) comparing deferasirox to placebo (n = 47) in people with transfusion-dependent thalassaemia showed that deferasirox leads to net iron excretion. In these studies, safety was acceptable and further investigation in phase II and phase III studies was warranted.Nine studies (1251 participants) provided data for deferasirox versus standard treatment with deferoxamine. Data suggest that a similar efficacy can be achieved depending on the ratio of doses of deferoxamine and deferasirox being compared. In the phase III study, similar or superior efficacy for the intermediate markers ferritin and liver iron concentration (LIC) could only be achieved in the highly iron-overloaded subgroup at a mean ratio of 1 mg of deferasirox to 1.8 mg of deferoxamine corresponding to a mean dose of 28.2 mg per day and 51.6 mg per day respectively. The pooled effects across the different dosing ratios are: serum ferritin, mean difference (MD) 454.42 ng/mL (95% confidence interval (CI) 337.13 to 571.71) (moderate quality evidence); LIC evaluated by biopsy or SQUID, MD 2.37 mg Fe/g dry weight (95% CI 1.68 to 3.07) (moderate quality evidence) and responder analysis, LIC 1 to < 7 mg Fe/g dry weight, risk ratio (RR) 0.80 (95% CI 0.69 to 0.92) (moderate quality evidence). The substantial heterogeneity observed could be explained by the different dosing ratios. Data on mortality (low quality evidence) and on safety at the presumably required doses for effective chelation therapy are limited. Patient satisfaction was better with deferasirox among those who had previously received deferoxamine treatment, RR 2.20 (95% CI 1.89 to 2.57) (moderate quality evidence). The rate of discontinuations was similar for both drugs (low quality evidence).For the remaining comparisons in people with transfusion-dependent thalassaemia, the quality of the evidence for outcomes assessed was low to very low, mainly due to the very small number of participants included. Four studies (205 participants) compared deferasirox to deferiprone; one of which (41 participants) revealed a higher number of participants experiencing arthralgia in the deferiprone group, but due to the large number of different types of adverse events reported and compared this result is uncertain. One study (96 participants) compared deferasirox combined with deferiprone to deferiprone with deferoxamine. Participants treated with the combination of the oral iron chelators had a higher adherence compared to those treated with deferiprone and deferoxamine, but no participants discontinued the study. In the comparisons of deferasirox versus combined deferasirox and deferiprone and that of deferiprone versus combined deferasirox and deferiprone (one study, 40 participants), and deferasirox and deferoxamine versus deferoxamine alone (one study, 94 participants), only a few patient-relevant outcomes were reported and no significant differences were observed.One study (166 participants) included people with non-transfusion dependent thalassaemia and compared two different doses of deferasirox to placebo. Deferasirox treatment reduced serum ferritin, MD -306.74 ng/mL (95% CI -398.23 to -215.24) (moderate quality evidence) and LIC, MD -3.27 mg Fe/g dry weight (95% CI -4.44 to -2.09) (moderate quality evidence), while the number of participants experiencing adverse events and rate of discontinuations (low quality evidence) was similar in both groups. No participant died, but data on mortality were limited due to a follow-up period of only one year (moderate quality evidence).

AUTHORS' CONCLUSIONS

Deferasirox offers an important treatment option for people with thalassaemia and secondary iron overload. Based on the available data, deferasirox does not seem to be superior to deferoxamine at the usually recommended ratio of 1 mg of deferasirox to 2 mg of deferoxamine. However, similar efficacy seems to be achievable depending on the dose and ratio of deferasirox compared to deferoxamine. Whether this will result in similar efficacy and will translate to similar benefits in the long term, as has been shown for deferoxamine, needs to be confirmed. Data from randomised controlled trials on rare toxicities and long-term safety are still limited. However, after a detailed discussion of the potential benefits and risks, deferasirox could be offered as the first-line option to individuals who show a strong preference for deferasirox, and may be a reasonable treatment option for people showing an intolerance or poor adherence to deferoxamine.

Assessment of Heart and Liver Iron Overload in Thalassemia Major Patients Using T2* Magnetic Resonance Imaging

Accumulation of excess iron in heart can lead to cardiac dysfunction, which is the most common cause of death in thalassemia major patients. Biopsy is an invasive procedure and therefore not an ideal option to assess iron load. However, standard/usual non-invasive methods, such as ferritin measurement, have some limitations and the results show poor correlations with iron load. Magnetic Response Imaging (MRI-T2*), as a non-invasive and reliable method for iron load assessment in organs such as liver and heart, can be suggested as a favorable alternative. This cross-sectional study was implemented in Thalassemia and Hemophilia Clinic Center (Sarvar) affiliated with Mashhad University of Medical Sciences, Mashhad, Iran, from 2012 to 2013. After the approval of the research protocol by the local ethic committee, laboratory tests, including CBC and serum ferritin, were carried out, and echocardiography and heart and liver MRI-T2* were performed. All statistical analysis was done through SPSS software (version 11.5), using independent sample t test and Pearson's correlation coefficient test. A P value ≤0.05 was considered to be significant. 88 patients with the mean (±SD) age of 21.2 (±5.6) years, (range 11-37 years) were observed. Iron load was assessed using MRI-T2* with the following results: Out of 88 patients, 48.9 % had mild to severe cardiac siderosis, and 75.2 % had mild to severe liver siderosis. We demonstrated a correlation between liver MRI-T2* and serum ferritin, and heart MRI-T2* and ejection fraction. However, no correlation between liver and heart MRI-T2* was observed. Heart and liver siderosis is a common and serious problem in thalassemia major patients, and MRI-T2* as a sensitive and non-invasive technique can be used for early/timely detection of siderosis and good therapeutic monitoring in these patients.

New developments and controversies in iron metabolism and iron chelation therapy

Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic haemochromatosis, thalassaemia intermedia and ex-thalassaemia transplanted patients who are safely treated with venesection. Iron chelating drugs can override normal regulatory pathways, correct iron imbalance and minimise iron toxicity. The use of iron chelating drugs as main, alternative or adjuvant therapy is in progress in many conditions, especially those with non established or effective therapies.

The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes

Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload.

Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters.

The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes.

Transition of Thalassaemia and Friedreich ataxia from fatal to chronic diseases

Thalassaemia major (TM) and Friedreich’s ataxia (FA) are autosomal recessive inherited diseases related to the proteins haemoglobin and frataxin respectively. In both diseases abnormalities in iron metabolism is the main cause of iron toxicity leading to increased morbidity and mortality. Major efforts are directed towards the prevention of these diseases and also in their treatment using iron chelation therapy. Both TM and FA are endemic in Cyprus, where the frequency per total population of asymptomatic heterozygote carriers and patients is the highest worldwide. Cyprus has been a pioneering nation in preventing and nearly eliminating the birth of TM and FA patients by introducing an organized health structure, including prenatal and antenatal diagnosis. Effective iron chelation therapy, improved diagnostic methods and transfusion techniques as well as supportive therapy from other clinical specializations have improved the survival and quality of life of TM patients. Despite the tiresome clinical management regimes many TM patients are successful in their professional lives, have families with children and some are now living well into their fifties. The introduction of deferiprone led to the elimination of cardiac failure induced by iron overload toxicity, which was the major cause of mortality in TM. Effective combinations of deferiprone with deferoxamine in TM patients caused the fall of body iron to normal physiological ranges. In FA different mechanisms of iron metabolism and toxicity apply to that of TM, which can be targeted with specific iron chelation protocols. Preliminary findings from the introduction of deferiprone in FA patients have increased the hopes for improved and effective therapy in this untreatable condition. New and personalised treatments are proposed in TM and FA. Overall, advances in treatments and in particular of chelation therapy using deferiprone are transforming TM and FA from fatal to chronic conditions. The paradigm of Cyprus in the prevention and treatment of TM can be used for application worldwide.

Deferasirox for managing iron overload in people with myelodysplastic syndrome

BACKGROUND

The myelodysplastic syndrome (MDS) comprises a diverse group of haematopoietic stem cell disorders. Due to symptomatic anaemia, most people with MDS require supportive therapy including repeated red blood cell (RBC) transfusions. In combination with increased iron absorption, this contributes to the accumulation of iron resulting in secondary iron overload and the risk of organ dysfunction and reduced life expectancy. Since the human body has no natural means of removing excess iron, iron chelation therapy, i.e. the pharmacological treatment of iron overload, is usually recommended. However, it is unclear whether or not the newer oral chelator deferasirox leads to relevant benefit.

OBJECTIVES

To evaluate the effectiveness and safety of oral deferasirox for managing iron overload in people with myelodysplastic syndrome (MDS).

SEARCH METHODS

We searched the following databases up to 03 April 2014: MEDLINE, EMBASE, The Cochrane Library, Biosis Previews, Web of Science, Derwent Drug File and four trial registries: Current Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), ICTRP (www.who.int./ictrp/en/), and German Clinical Trial Register (www.drks.de).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing deferasirox with no therapy, placebo or with another iron-chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

We did not identify any trials eligible for inclusion in this review.

MAIN RESULTS

No trials met our inclusion criteria. However, we identified three ongoing and one completed trial (published as an abstract only and in insufficient detail to permit us to decide on inclusion) comparing deferasirox with deferoxamine, placebo or no treatment.

AUTHORS' CONCLUSIONS

We planned to report evidence from RCTs that evaluated the effectiveness of deferasirox compared to either placebo, no treatment or other chelating regimens, such as deferoxamine, in people with MDS. However, we did not identify any completed RCTs addressing this question.We found three ongoing and one completed RCT (published as an abstract only and in insufficient detail) comparing deferasirox with deferoxamine, placebo or no treatment and data will hopefully be available soon. These results will be important to inform physicians and patients on the advantages and disadvantages of this treatment option.

The Role of Magnetic Resonance Imaging in the Evaluation of Thalassemic Syndromes: Current Practice and Future Perspectives

Iron can be deposited in all internal organs, leading to different types of functional abnormalities. However, myocardial iron overload that contributes to heart failure remains one of the main causes of death in thalassemia major. Using magnetic resonance imaging, tissue iron is detected indirectly by the effects on relaxation times of ferritin and hemosiderin iron interacting with hydrogen nuclei. The presence of iron in the human body results in marked alterations of tissue relaxation times. Currently, cardiovascular magnetic resonance using T2* is routinely used in many countries to identify patients with myocardial iron loading and guide chelation therapy, specifically tailored to the heart. Myocardial T2* is the only clinically validated non-invasive measure of myocardial iron loading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. Finally, the substantial amelioration of patients’ survival, allows the detection of other organs’ abnormalities due to iron overload, apart from the heart, missed in the past. Recent studies revealed that iron deposition has a different pattern in various parenchymal organs, which is independent from serum ferritin and follows an individual way after chelation treatment application. This new upcoming reality orders a closer monitoring of all organs of the body in order to detect preclinical lesions and early apply adequate treatment.

World health dilemmas: Orphan and rare diseases, orphan drugs and orphan patients

According to global annual estimates hunger/malnutrition is the major cause of death (36 of 62 million). Cardiovascular diseases and cancer (5.44 of 13.43 million) are the major causes of death in developed countries, while lower respiratory tract infections, human immunodeficiency virus infection/acquired immunodeficiency syndrome, diarrhoeal disease, malaria and tuberculosis (10.88 of 27.12 million) are the major causes of death in developing countries with more than 70% of deaths occurring in children. The majority of approximately 800 million people with other rare diseases, including 100000 children born with thalassaemia annually receive no treatment. There are major ethical dilemmas in dealing with global health issues such as poverty and the treatment of orphan and rare diseases. Of approximately 50000 drugs about 10% are orphan drugs, with annual sales of the latter approaching 100 billion USD. In comparison, the annual revenue in 2009 from the top 12 pharmaceutical companies in Western countries was 445 billion USD and the top drug, atorvastatin, reached 100 billion USD. In the same year, the total government expenditure for health in the developing countries was 410 billion USD with only 6%-7% having been received as aid from developed countries. Drugs cost the National Health Service in the United Kingdom more than 20 billion USD or 10% of the annual health budget. Uncontrollable drug prices and marketing policies affect global health budgets, clinical practice, patient safety and survival. Fines of 5.3 billion USD were imposed on two pharmaceutical companies in the United States, the regulatory authority in France was replaced and clinicians were charged with bribery in order to overcome recent illegal practises affecting patient care. High expenditure for drug development is mainly related to marketing costs. However, only 2 million USD was spent developing the drug deferiprone (L1) for thalassaemia up to the stage of multicentre clinical trials. The criteria for drug development, price levels and use needs to be readdressed to improve drug safety and minimise costs. New global health policies based on cheaper drugs can help the treatment of many categories of orphan and rare diseases and millions of orphan patients in developing and developed countries.

Deferasirox for managing transfusional iron overload in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a group of genetic haemoglobin disorders, that occurs in about 2.2 per 1000 births worldwide. Increasingly, some people with SCD develop secondary iron overload due to occasional red blood cell transfusions or are on long-term transfusion programmes for e.g. secondary stroke prevention. Iron chelation therapy can prevent long-term complications.Deferoxamine and deferiprone have been found to be efficacious. However, questions exist about the effectiveness and safety of the newer oral chelator deferasirox.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with SCD and secondary iron overload.

SEARCH METHODS

We searched the Cystic Fibrosis &amp; Genetic Disorders Group's Haemoglobinopathies Trials Register: date of most recent search:13 March 2014.We searched MEDLINE, Embase, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE, EBMR and The Cochrane Library, respectively; date of most recent searches: 02 August 2013.We searched four trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/; www.drks.de; date of most recent searches: 03 June 2013.

SELECTION CRITERIA

Randomised controlled trials comparing deferasirox with no therapy or placebo or with another iron chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We contacted the corresponding study authors for additional information.

MAIN RESULTS

Two studies (with 203 and 212 people) comparing the efficacy and safety of deferasirox and deferoxamine after 12 months and 24 weeks, respectively, were included. The overall quality, according to GRADE, for the main outcomes was moderate to low. Only limited data were available on mortality and end-organ damage, although one study did assess mortality, relative risk 1.26 (95% confidence interval 0.05 to 30.41), the 24-week follow up was too short to allow us to draw firm conclusions. One study reported a relative risk of 1.26 for the incidence of type 2 diabetes mellitus (95% confidence interval 0.05 to 30.41). Serum ferritin reduction was significantly greater with deferoxamine, mean difference of change of 440.69 µg/l (95% confidence interval 11.73 to 869.64). Liver iron concentration (reported in one study) measured by superconduction quantum interference device showed no significant difference for the overall group of patients adjusted for transfusion category, mean difference -0.20 mg Fe/g dry weight (95% confidence interval -3.15 to 2.75).The occurrence of serious adverse events did not differ between drugs. Nausea, diarrhoea and rash occurred significantly more often in people treated with deferasirox, while adverse events of any kind were more often reported for patients treated with deferoxamine (one study). The mean increase of creatinine was also significantly higher with deferasirox, mean difference 3.24 (95% confidence interval 0.45 to 6.03). Long-term adverse events could not be measured in the included studies (follow up 52 weeks and 24 weeks). Patient satisfaction and the likelihood of continuing treatment, were significantly better with deferasirox.

AUTHORS' CONCLUSIONS

Deferasirox appears to be of similar efficacy to deferoxamine depending on depending on the appropriate ratio of doses of deferoxamine and deferasirox being compared. However, only limited evidence is available assessing the efficacy regarding patient-important outcomes. The short-term safety of deferasirox seems to be acceptable, however, follow up in the available studies was too short to assess long-term side effects. Long-term safety and efficacy data are available from a non-controlled extension phase not included in our review; however, no valid comparative conclusions can be drawn and future studies should assess comparatively long-term outcomes both for safety and efficacy.

Potential clinical applications of chelating drugs in diseases targeting transferrin-bound iron and other metals

INTRODUCTION

Iron is essential for normal, neoplasmic and microbial cells. Transferrin (Tf) is responsible for iron transport and its interactions with chelators are of physiological and toxicological importance and could lead to new therapeutic applications.

AREAS COVERED

Differential interactions of Tf with chelators such as deferiprone (L1) could be used to modify toxicity and disease pathways in relation to iron and other metal metabolism. Iron mobilization by L1 could achieve normal body iron stores in thalassemia patients. Iron mobilization from the reticuloendothelial system by L1 and exchange with Tf could be used to increase the production of hemoglobin in the anemia of chronic disease. Iron accumulation is pathogenic in neurodegenerative, acute kidney and other diseases and could be removed by L1 with therapeutic implications. Deprivation of iron from neoplasmic and microbial cells by chelators could increase the prospect of improved treatments in cancer and infectious diseases. Other applications include metal detoxification and inhibition of oxidative stress-related conditions.

EXPERT OPINION

Specific mechanisms apply in the interactions of chelators with Tf, which could be used in the design of targeted therapeutic strategies in many conditions. In each case specific chelator protocols have to be designed for achieving optimum therapeutic activity.

Deferasirox for the treatment of iron overload in non-transfusion-dependent thalassemia

Non-transfusion-dependent thalassemia (NTDT) defines a group of patients who do not require regular transfusions for survival, but are at significant risk of iron accumulation from underlying disease-related mechanisms distinct from transfusional iron overload. Management of iron overload in NTDT has received little attention compared with that of β-thalassemia major, despite evidence of significant iron-induced complications with advancing age. The efficacy and safety of the iron chelator deferasirox in NTDT has been evaluated in two pilot studies and the first prospective, randomized, placebo-controlled study (THALASSA) of any chelator in NTDT. Treatment with deferasirox for up to 2 years yielded a sustained reduction in iron burden, with a clinically manageable safety profile. Following these trial data, deferasirox is the first iron chelator approved for use in NTDT patients, and with NTDT guidelines now available, physicians are better equipped to achieve effective monitoring and management of iron burden in NTDT.

International survey of T2* cardiovascular magnetic resonance in β-thalassemia major

Accumulation of myocardial iron is the cause of heart failure and early death in most transfused thalassemia major patients. T2* cardiovascular magnetic resonance provides calibrated, reproducible measurements of myocardial iron. However, there are few data regarding myocardial iron loading and its relation to outcome across the world. A survey is reported of 3,095 patients in 27 worldwide centers using T2* cardiovascular magnetic resonance. Data on baseline T2* and numbers of patients with symptoms of heart failure at first scan (defined as symptoms and signs of heart failure with objective evidence of left ventricular dysfunction) were requested together with more detailed information about patients who subsequently developed heart failure or died. At first scan, 20.6% had severe myocardial iron (T2*≤ 10 ms), 22.8% had moderate myocardial iron (T2* 10-20 ms) and 56.6% of patients had no iron loading (T2*>20 ms). There was significant geographical variation in myocardial iron loading (24.8-52.6%; P<0.001). At first scan, 85 (2.9%) of 2,915 patients were reported to have heart failure (81.2% had T2* <10 ms; 98.8% had T2* <20 ms). During follow up, 108 (3.8%) of 2,830 patients developed new heart failure. Of these, T2* at first scan had been less than 10 ms in 96.3% and less than 20 ms in 100%. There were 35 (1.1%) cardiac deaths. Of these patients, myocardial T2* at first scan had been less than 10 ms in 85.7% and less than 20 ms in 97.1%. Therefore, in this worldwide cohort of thalassemia major patients, over 43% had moderate/severe myocardial iron loading with significant geographical differences, and myocardial T2* values less than 10 ms were strongly associated with heart failure and death.

Liver iron and serum ferritin levels are misleading for estimating cardiac, pancreatic, splenic and total body iron load in thalassemia patients: factors influencing the heterogenic distribution of excess storage iron in organs as identified by MRI T2*

A comparative assessment of excess storage iron distribution in the liver, heart, spleen and pancreas of β-thalassemia major (β-ΤΜ) patients has been carried out using magnetic resonance imaging (MRI) relaxation times T2*. The β-ΤΜ patients (8-40 years, 11 males, 9 females) had variable serum ferritin levels (394-5603 μg/L) and were treated with deferoxamine (n = 10), deferiprone (n = 5) and deferoxamine/deferiprone combination (n = 5). MRI T2* assessment revealed that excess iron is not proportionally distributed among the organs but is stored at different concentrations in each organ and the distribution is different for each β-ΤΜ patient. There is random variation in the distribution of excess storage iron from normal to severe levels in each organ among the β-ΤΜ patients by comparison to the same organs of ten normal volunteers. The correlation of serum ferritin with T2* was for spleen (r = -0.81), liver (r = -0.63), pancreas (r = -0.33) and none with heart. Similar trend was observed in the correlation of liver T2* with the T2* of spleen (r = 0.62), pancreas (r = 0.61) and none with heart. These studies contradict previous assumptions that serum ferritin and liver iron concentration is proportional to the total body iron stores in β-ΤΜ and especially cardiac iron load. The random variation in the concentration of iron in the organs of β-ΤΜ patients appears to be related to the chelation protocol, organ function, genetic, dietary, pharmacological and other factors. Monitoring of the iron load for all the organs is recommended for each β-ΤΜ patient.

The importance of spleen, spleen iron, and splenectomy for determining total body iron load, ferrikinetics, and iron toxicity in thalassemia major patients

The importance of spleen, spleen iron and splenectomy has been investigated in 28 male and 19 female β-thalassemia major (β-ΤΜ), adult patients. In one study, an increase from about five (615 g; 19.5 × 11.0 × 6.0 cm) to twenty (2030 g; 25.0 × 17.5 × 12.0 cm) times higher than the normal size and weight of spleen has been observed in twenty patients following splenectomy. In a second study, the mean size for the liver (19.4 cm, range 13.5-26.0 cm) and spleen (15.6 cm, range 7.0-21.0 cm) measured by magnetic resonance imaging (MRI) and by ultrasound imaging for spleen (15.1 cm, range 9.0-21.0 cm) of 16 patients indicated that on average the spleen is about 80% of the size of the liver. In the third study, comparison of the iron load using MRI T(2)* and iron grading of stained biopsies indicated that substantial but variable amounts of excess iron are stored in the spleen (0-40%) in addition to that in the liver. Following splenectomy, total body iron storage capacity is reduced, whereas serum ferritin (p = 0.0085) and iron concentration in other organs appears to increase despite the reduction in the rate of transfusions (p = 0.0001) and maintenance of hemoglobin levels (p = 0.1748). Spleen iron seems to be cleared faster than liver iron using effective chelation protocols. Spleen iron is a major constituent of the total body iron load in β-ΤΜ patients and should be regularly monitored and targeted for chelation. Normalization of the body iron stores at an early age could maintain the spleen in near normal capacity and secondary effects such as cardiac and other complications could be avoided.

Deferasirox for managing iron overload in people with thalassaemia

BACKGROUND

Thalassemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusion. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone have been found to be efficacious. However, a systematic review of the effectiveness and safety of the new oral chelator deferasirox in people with thalassaemia is needed.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and secondary iron overload.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We also searched MEDLINE, EMBASE, EBMR, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE and three trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/. Date of the most recent searches of these databases: 24 June 2010.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 03 November 2011.

SELECTION CRITERIA

Randomised controlled trials comparing deferasirox with no therapy or placebo or with another iron chelating treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Four studies met the inclusion criteria.Two studies compared deferasirox to placebo or standard therapy of deferoxamine (n = 47). The placebo-controlled studies, a pharmacokinetic and a dose escalation study, showed that deferasirox leads to net iron excretion in transfusion-dependent thalassaemia patients. In these studies, safety was acceptable and further investigation in phase II and phase III trials was warranted.Two studies, one phase II study (n = 71) and one phase III study (n = 586) compared deferasirox to standard treatment with deferoxamine. Data suggest that a similar efficacy can be achieved depending on the ratio of doses of deferoxamine and deferasirox being compared; in the phase III trial, similar or superior efficacy for surrogate parameters of ferritin and liver iron concentration could only be achieved in the highly iron-overloaded subgroup at a mean ratio of 1 mg of deferasirox to 1.8 mg of deferoxamine corresponding to a mean dose of 28.2 mg/d and 51.6 mg/d respectively. Data on safety at the presumably required doses for effective chelation therapy are limited. Patient satisfaction was significantly better with deferasirox, while rate of discontinuations was similar for both drugs.

AUTHORS' CONCLUSIONS

Deferasirox offers an important alternative line of treatment for people with thalassaemia and secondary iron overload. Based on the available data, deferasirox does not seem to be superior to deferoxamine at the usually recommended ratio of 1 mg of deferasirox to 2 mg of deferoxamine. However, similar efficacy seems to be achievable depending on the dose and ratio of deferasirox compared to deferoxamine. Whether this will result in similar efficacy in the long run and will translate to similar benefits as has been shown for deferoxamine, needs to be confirmed. Data on safety, particularly on rare toxicities and long-term safety, are still limited.Therefore, we think that deferasirox should be offered as an alternative to all patients with thalassaemia who either show intolerance to deferoxamine or poor compliance with deferoxamine. In our opinion, data are still too limited to support the general recommendation of deferasirox as first-line treatment instead of deferoxamine. If a strong preference for deferasirox is expressed, it could be offered as first-line option to individual patients after a detailed discussion of the potential benefits and risks.

Efficacy, compliance and toxicity factors are affecting the rate of normalization of body iron stores in thalassemia patients using the deferiprone and deferoxamine combination therapy

The international committee on chelation (ICOC) of deferiprone (L1) and deferoxamine (DFO) combination therapy was the first protocol reported to have achieved normal range body iron store levels (NRBISL) in β-thalassemia major (β-TM) patients. A follow-up study in eight β-TM patients has been designed to investigate the factors affecting the rate of iron removal leading to NRBISL. The patients had variable serum ferritin [mean ± SE (standard error) =1692 ± 366, range 539-3845 μg/L)] and magnetic resonance imaging (MRI) T2* relaxation times cardiac (mean ± SE =11.1 ± 2.5, range 4.5-24.2 ms) and liver (mean ± SE = 4.3 ± 1.8, range 1.4-14 ms). Organ function, blood and other biochemical parameters were regularly monitored for toxicity. The ICOC L1 (80-100 mg/kg/day) and DFO (40-60 mg/kg, at least 3 days per week) combination therapy caused an increase in cardiac (mean ± SE =30.2 ± 2.3, range 22-41 ms) and liver (mean ± SE =27.6 ± 2.8, range 9.1-35 ms) T2* and reduction in serum ferritin (mean ± SE = 158 ± 49, range 40-421 μg/L) to within the NRBISL. The rate of normalization was variable and in one case was achieved within 9 months, whereas the longest was about 3 years. The initial iron load, the rate of transfusions, the combination dose protocol and the level of compliance were the major factors affecting the rate of normalization of the iron stores. No serious toxicity was observed during the study period, which lasted a total of 24.7 patient years.

The proceedings of the 19Th international conference on chelation held in London, United Kingdom: major changes in iron chelation therapy in the last 25 years using deferiprone (L1) has resulted in the complete treatment of iron overload

Major advances were presented at the 19th International Conference on Chelation (ICOC) in London, UK including changes in iron chelation therapy that led to the complete treatment of transfusional iron overload. The first oral iron chelation results in animals using deferiprone (L1) were published in 1985, and effective iron removal in thalassemia and myelodysplasia patients were reported 2 years later. The results of multicenter clinical trials of L1 were presented at the 1st ICOC in London, UK in 1989. Long-term use of L1 resulted in the reduction of the mortality rate in thalassemia patients due to the effective removal of all excess iron from the heart. In 2008, specific combinations of L1 and deferoxamine (DFO) were reported to cause the complete removal of excess iron load and the achievement of normal range body iron store levels (NRBISL) in thalassemia patients. Patients with NRBISL were identified to require lower doses of L1 for the maintenance of negative iron balance. The introduction of deferasirox (DFRA) may benefit patients not tolerating L1, DFO or their combination. A simple, inexpensive synthesis of L1 has encouraged its manufacture in developing countries for the benefit of patients who could not afford the expensive imported chelating drugs or formulations.

Reduction of body iron stores to normal range levels in thalassaemia by using a deferiprone/deferoxamine combination and their maintenance thereafter by deferiprone monotherapy

BACKGROUND

Iron overload and toxicity is the major cause of morbidity and mortality in thalassaemia patients. New chelating drug protocols are necessary to treat completely transfusional iron overload and eliminate associated toxicity. Appropriate deferiprone/deferoxamine combinations could achieve this goal.

METHODS

A single-centre, single-armed, proof-of-concept study of the combination of deferiprone (75-100 mg/kg/d) and deferoxamine (40-60 mg/kg, at least 3 d per week) was carried out in eight patients with thalassaemia major (four men and four women) for 21-68 months. The patients were previously treated with deferoxamine and had variable serum ferritin [geometric (G) mean ± SD = 1446 ± 1035 μg/L] and magnetic resonance imaging relaxation times T2* cardiac (Gmean ± SD = 10.32 ± 6.72 ms) and liver (G mean ± SD = 3.77 ± 4.69 ms). The use of deferiprone (80-100 mg/kg/d) continued for 7-26 months in seven of the eight patients following the combination therapy. Organ function, blood and other biochemical parameters were monitored for toxicity.

RESULTS

  The deferiprone/deferoxamine combination caused an absolute value increase in cardiac (G mean ± SD = 29.6 ± 6.6 ms, P < 0.00076) and liver (G mean ± SD = 25.9 ± 8.07 ms, P < 0.00075) T2* and reduction in serum ferritin (G mean ± SD = 114.7 ± 139.8 μg/L, P < 0.0052) to within the normal body iron store range levels. In two cases, normalisation was achieved within a year. Deferiprone monotherapy was sufficient thereafter in maintaining normal range cardiac (G mean ± SD = 31.4 ± 5.25 ms, P < 0.79) and liver (G mean ± SD = 26.2 ± 12.4 ms, P < 0.58) T2* and normal serum ferritin (G mean ± SD = 150.7 ± 159.1, μg/L, P < 0.17) in five of the seven patients. No serious toxicity was observed.

CONCLUSION

  Transfusional iron overload in patients with thalassaemia could be reduced to normal body iron range levels using effective deferiprone/deferoxamine combinations. These levels could be maintained using deferiprone monotherapy.

Deferasirox for managing iron overload in people with myelodysplastic syndrome

BACKGROUND

The myelodysplastic syndrome (MDS) comprises a diverse group of haematopoietic stem cell disorders. Due to symptomatic anaemia most patients require supportive therapy including repeated red blood cell (RBC) transfusions. In combination with increased iron absorption, this contributes to the accumulation of iron resulting in secondary iron overload and the risk of organ dysfunction and reduced life expectancy. Since the human body has no natural means of getting rid of excess iron, iron chelation therapy is usually recommended. However, whether the new oral chelator deferasirox leads to relevant benefit is unclear.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with myelodysplastic syndrome and iron overload.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, The Cochrane Library, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE and three trial registries: Current Controlled Trials: www.controlled-trials.com, ClinicalTrials.gov: www.clinicaltrials.gov, ICTRP: www.who.int./ictrp/en/. Most recent searches of these databases: June 2010.

SELECTION CRITERIA

Randomised controlled trials comparing deferasirox with no therapy/placebo or with another iron chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

No studies eligible for inclusion in this review were identified.

MAIN RESULTS

No studies were included in this review. However, we identified one ongoing study comparing deferasirox with deferoxamine.

AUTHORS' CONCLUSIONS

We planned to report evidence from randomised clinical trials evaluating the effectiveness of deferasirox compared to either placebo/no treatment or other chelating regimens such as deferoxamine in people with myelodysplastic syndrome. However, no completed randomised trials addressing this question could be identified.One ongoing randomised study comparing deferasirox with placebo was identified and preliminary data will hopefully be available soon. These results will be important to inform physicians and patients on the advantages and disadvantages of this treatment option.

Introduction of higher doses of deferasirox: better efficacy but not effective iron removal from the heart and increased risks of serious toxicities

IMPORTANCE OF THE FIELD

Thousands of iron loaded patients are using deferasirox, who are not aware of the new, fatal and irreversible serious toxic side effects, the need for prophylaxis and the availability of more effective and less toxic chelation therapies.

AREAS COVERED IN THIS REVIEW

Updating on efficacy issues in relation to the introduction of higher deferasirox doses and comparison to existing chelation therapies. A new maximum dose of 40 mg/kg/day has been introduced for deferasirox in an attempt to achieve negative iron balance in thalassemia and other transfused iron loaded patients. A marginal increase in cardiac iron removal using doses of 30 - 40 mg/kg/day suggests that the rate of iron removal by deferasirox is insufficient by comparison to the deferiprone/deferoxamine combination, where total and rapid clearance of excess cardiac iron and normalization of the body iron stores could be achieved.

WHAT THE READER WILL GAIN

Identification of drug interactions and new fatal and permanent toxic side effects of deferasirox and implications on efficacy, toxicity and cost of using higher doses. Deferasirox has been identified to cause fatal gastrointestinal hemorrhages, renal tubulopathy, hepatic and renal failure, alopecia and anaphylactic reactions in addition to previously reported fatal or serious toxic side effects such as agranulocytosis, renal and hepatic toxicity, skin rash and gastric intolerance. Interactions with UDP-glucuronosyl transferase inducers, CYP2C8 and CYP3A4 substrates and drugs affecting enterohepatic recycling are likely to affect deferasirox's efficacy and toxicity. Increased toxicity is expected from the use of higher doses of deferasirox and regular prophylactic monitoring is required to avoid fatal and permanent toxicity incidences. The increased costs from higher doses of deferasirox will mostly affect patients living in the developing countries.

TAKE HOME MESSAGE

Only few patients may benefit from the introduction of higher doses of deferasirox. There is a need for introducing more effective prophylactic measures. Safer, more effective and less costly chelation treatments are available using deferiprone, deferoxamine and their combination.

Safety issues of iron chelation therapy in patients with normal range iron stores including thalassaemia, neurodegenerative, renal and infectious diseases

An increased number of thalassaemia patients treated with effective chelation therapy protocols are achieving body iron levels similar to those of normal individuals. Iron chelation therapy has also been recently used in a number of other categories of patients with no excess body iron load such as neurodegenerative, renal and infectious diseases. Chelation therapy in the absence of iron overload in the latter conditions raises many safety issues including chelator overdose toxicity and toxicity related to iron and other essential metal deficiencies. Preliminary preclinical and clinical toxicity evidence suggest that deferoxamine and deferasirox can only be safely used for these non-iron loaded conditions for short-term treatments of a few weeks, whereas deferiprone can be used for longer term treatments of many months. The selection of the chelating drug and appropriate dose protocols for targeting specific organs and conditions is critical for the safety of patients with normal iron stores. Chelation therapy is likely to play a major role as adjuvant, alternative or main therapy in many non-iron loading conditions in the forthcoming years.

Deferasirox for managing transfusional iron overload in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a group of genetic haemoglobin disorders. Increasingly, some people with SCD develop secondary iron overload due to occasional red blood cell transfusions or are on long-term transfusion programmes for e.g. secondary stroke prevention. Iron chelation therapy can prevent long-term complications.Deferoxamine and deferiprone have been found to be efficacious. However, questions exist about the effectiveness and safety of the new oral chelator deferasirox.

OBJECTIVES

To assess the effectiveness and safety of oral deferasirox in people with SCD and secondary iron overload.

SEARCH STRATEGY

We searched the Cystic Fibrosis & Genetic Disorders Group's Haemoglobinopathies Trials Register (06 April 2010).We searched MEDLINE, EMBASE, EBMR, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE and three trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/. Most recent searches: 22 June 2009.

SELECTION CRITERIA

Randomised controlled trials comparing deferasirox with no therapy or placebo or with another iron chelating treatment schedule.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We contacted the study author for additional information.

MAIN RESULTS

One study (203 people) was included comparing the efficacy and safety of deferasirox and deferoxamine after 12 months. Data were not available on mortality or end-organ damage. Using a pre-specified dosing algorithm serum ferritin reduction was similar in both groups, mean difference (MD) 375.00 microg/l in favour of deferoxamine; (95% confidence interval (CI) -106.08 to 856.08). Liver iron concentration measured by superconduction quantum interference device showed no difference for the overall group of patients adjusted for transfusion category, MD -0.20 mg Fe/g dry weight (95% CI -3.15 to 2.75).Mild stable increases in creatine were observed more often in people treated with deferasirox, risk ratio 1.64 (95% CI 0.98 to 2.74). Abdominal pain and diarrhoea occurred significantly more often in people treated with deferasirox. Rare adverse events (less than 5% increase) were not reported; long-term adverse events could not be measured in the included study (follow-up 52 weeks). Patient satisfaction with, and convenience of treatment were significantly better with deferasirox.

AUTHORS' CONCLUSIONS

Deferasirox appears to be as effective as deferoxamine. However, only limited evidence is available assessing the efficacy regarding patient-important outcomes. The short-term safety of deferasirox seems to be acceptable, however, follow-up was too short to exclude long-term side effects and thus treatment with deferasirox cannot be judged completely safe. Future studies should assess long-term outcomes for safety and efficacy, and also evaluate rarer adverse effects.

Deferoxamine versus combined therapy for chelating liver, spleen and bone marrow iron in beta-thalassemic patients: a quantitative magnetic resonance imaging study

We used magnetic resonance imaging (MRI) to compare the effect of iron chelation on liver, spleen and bone marrow. We examined 21 beta-thalassemic patients undergoing deferoxamine (DFO) (9/21) or combined therapy [DFO and deferiprone (L1), 12/21] with two abdominal MRI studies using T1-w/Pd-w/T2*-wGRE and T1-wTSE sequences. Changes in serum ferritin (DF%), and liver, spleen and marrow to paraspinous muscles signal intensity ratios (SI) in T1-wTSE sequence were calculated as D%=[(2(nd)value-1(st) value)/1(st) value] x100%. Negative DF% and positive D(SI)% indicated reduction of iron. Although 17/21 (80.9%) patients demonstrated reduction in ferritin, only 8/21 (38%), 7/21 (33.3%) and 7/21 (33.3%) patients had decreased liver, spleen and marrow iron. Patients undergoing combined therapy showed significantly greater reduction (Student's t-test, p < 0.05) or less increase (t-test, p <0.05) in iron stores. Combined therapy is more effective than DFO for removing and preventing liver, spleen and bone marrow iron accumulation in beta-thalassemic patients. Magnetic resonance imaging is valuable for organ-specific monitoring of chelation therapy.