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Neurology Mar 2018To systematically review evidence regarding ataxia treatment.
Comprehensive systematic review summary: Treatment of cerebellar motor dysfunction and ataxia: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology.
OBJECTIVE
To systematically review evidence regarding ataxia treatment.
METHODS
A comprehensive systematic review was performed according to American Academy of Neurology methodology.
CONCLUSIONS
For patients with episodic ataxia type 2, 4-aminopyridine 15 mg/d probably reduces ataxia attack frequency over 3 months (1 Class I study). For patients with ataxia of mixed etiology, riluzole probably improves ataxia signs at 8 weeks (1 Class I study). For patients with Friedreich ataxia or spinocerebellar ataxia (SCA), riluzole probably improves ataxia signs at 12 months (1 Class I study). For patients with SCA type 3, valproic acid 1,200 mg/d possibly improves ataxia at 12 weeks. For patients with spinocerebellar degeneration, thyrotropin-releasing hormone possibly improves some ataxia signs over 10 to 14 days (1 Class II study). For patients with SCA type 3 who are ambulatory, lithium probably does not improve signs of ataxia over 48 weeks (1 Class I study). For patients with Friedreich ataxia, deferiprone possibly worsens ataxia signs over 6 months (1 Class II study). Data are insufficient to support or refute the use of numerous agents. For nonpharmacologic options, in patients with degenerative ataxias, 4-week inpatient rehabilitation probably improves ataxia and function (1 Class I study); transcranial magnetic stimulation possibly improves cerebellar motor signs at 21 days (1 Class II study). For patients with multiple sclerosis-associated ataxia, the addition of pressure splints possibly has no additional benefit compared with neuromuscular rehabilitation alone (1 Class II study). Data are insufficient to support or refute use of stochastic whole-body vibration therapy (1 Class III study).
Topics: Ataxia; Cerebellar Diseases; Humans
PubMed: 29440566
DOI: 10.1212/WNL.0000000000005055 -
The Cochrane Database of Systematic... Aug 2017Thalassaemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Administration, Oral; Benzoates; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Deferasirox; Deferiprone; Deferoxamine; Erythrocyte Transfusion; Ferritins; Humans; Iron Chelating Agents; Iron Overload; Patient Satisfaction; Pyridones; Randomized Controlled Trials as Topic; Thalassemia; Triazoles
PubMed: 28809446
DOI: 10.1002/14651858.CD007476.pub3 -
The Cochrane Database of Systematic... Aug 2016Friedreich ataxia is a rare inherited autosomal recessive neurological disorder, characterised initially by unsteadiness in standing and walking, slowly progressing to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Friedreich ataxia is a rare inherited autosomal recessive neurological disorder, characterised initially by unsteadiness in standing and walking, slowly progressing to wheelchair dependency usually in the late teens or early twenties. It is associated with slurred speech, scoliosis, and pes cavus. Heart abnormalities cause premature death in 60% of people with the disorder. There is no easily defined clinical or biochemical marker and no known treatment. This is the second update of a review first published in 2009 and previously updated in 2012.
OBJECTIVES
To assess the effects of pharmacological treatments for Friedreich ataxia.
SEARCH METHODS
On 29 February 2016 we searched The Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, EMBASE and CINAHL Plus. On 7 March 2016 we searched ORPHANET and TRIP. We also checked clinical trials registers for ongoing studies.
SELECTION CRITERIA
We considered randomised controlled trials (RCTs) or quasi-RCTs of pharmacological treatments (including vitamins) in people with genetically-confirmed Friedreich ataxia. The primary outcome was change in a validated Friedreich ataxia neurological score after 12 months. Secondary outcomes were changes in cardiac status as measured by magnetic resonance imaging or echocardiography, quality of life, mild and serious adverse events, and survival. We excluded trials of duration shorter than 12 months.
DATA COLLECTION AND ANALYSIS
Three review authors selected trials and two review authors extracted data. We obtained missing data from the two RCTs that met our inclusion criteria. We collected adverse event data from included studies. We used standard methodological procedures expected by Cochrane.
MAIN RESULTS
We identified more than 12 studies that used antioxidants in the treatment of Friedreich ataxia, but only two small RCTs, with a combined total of 72 participants, both fulfilled the selection criteria for this review and published results. One of these trials compared idebenone with placebo, the other compared high-dose versus low-dose coenzyme Q10 and vitamin E (the trialists considered the low-dose medication to be the placebo). We identified two other completed RCTs, which remain unpublished; the interventions in these trials were pioglitazone (40 participants) and idebenone (232 participants). Other RCTs were of insufficient duration for inclusion.In the included studies, the primary outcome specified for the review, change in a validated Friedreich ataxia rating score, was measured using the International Co-operative Ataxia Rating Scale (ICARS). The results did not reveal any significant difference between the antioxidant-treated and the placebo groups (mean difference 0.79 points, 95% confidence interval -1.97 to 3.55 points; low-quality evidence).The published included studies did not assess the first secondary outcome, change in cardiac status as measured by magnetic resonance imaging. Both studies reported changes in cardiac measurements assessed by echocardiogram. The ejection fraction was not measured in the larger of the included studies (44 participants). In the smaller study (28 participants), it was normal at baseline and did not change with treatment. End-diastolic interventricular septal thickness showed a small decrease in the smaller of the two included studies. In the larger included study, there was no decrease, showing significant heterogeneity in the study results; our overall assessment of the quality of evidence for this outcome was very low. Left ventricular mass (LVM) was only available for the smaller RCT, which showed a significant decrease. The relevance of this change is unclear and the quality of evidence low.There were no deaths related to the treatment with antioxidants. We considered the published included studies at low risk of bias in six of seven domains assessed. One unpublished included RCT, a year-long study using idebenone (232 participants), published an interim report in May 2010 stating that the study reached neither its primary endpoint, which was change in the ICARS score, nor a key cardiological secondary endpoint, but data were not available for verification and analysis.
AUTHORS' CONCLUSIONS
Low-quality evidence from two small, published, randomised controlled trials neither support nor refute an effect from antioxidants (idebenone, or a combination of coenzyme Q10 and vitamin E) on the neurological status of people with Friedreich ataxia, measured with a validated neurological rating scale. A large unpublished study of idebenone that reportedly failed to meet neurological or key cardiological endpoints, and a trial of pioglitazone remain unpublished, but on publication will very likely influence quality assessments and conclusions. A single study of idebenone provided low-quality evidence for a decrease in LVM, which is of uncertain clinical significance but of potential importance that needs to be clarified. According to low-quality evidence, serious and non-serious adverse events were rare in both antioxidant and placebo groups. No non-antioxidant agents have been investigated in RCTs of 12 months' duration.
Topics: Antioxidants; Friedreich Ataxia; Heart; Humans; Hypertrophy, Left Ventricular; Randomized Controlled Trials as Topic; Rare Diseases; Ubiquinone; Ultrasonography; Vitamin E
PubMed: 27572719
DOI: 10.1002/14651858.CD007791.pub4 -
Hemoglobin 2014β-Thalassemia major (β-TM) patients require life-long blood transfusions, resulting in iron overload with multi-organ morbidity and mortality. Evidence from small... (Meta-Analysis)
Meta-Analysis Review
A systematic review and meta-analysis of deferiprone monotherapy and in combination with deferoxamine for reduction of iron overload in chronically transfused patients with β-thalassemia.
β-Thalassemia major (β-TM) patients require life-long blood transfusions, resulting in iron overload with multi-organ morbidity and mortality. Evidence from small randomized controlled trials (RCTs) published to date for deferiprone (DFP) monotherapy or in combination with deferoxamine (DFO) is unclear. We summarized evidence on the efficacy of DFP monotherapy compared to DFO, and DFP-DFO combination therapy compared to DFP or DFO monotherapy in chronically transfused β-TM. We searched four electronic databases and examined the grey literature. Two authors independently assessed trial quality and extracted data. We calculated the relative risk for dichotomous outcomes and mean difference (MD) for continuous outcomes. We identified 15 RCTs (1003 participants) that met the inclusion criteria. Deferiprone was more efficacious than DFO in improving cardiac ejection fraction [MD 2.88, 95% CI (95% confidence interval) 1.12 to 4.64, p = 0.001) and endocrine dysfunction (MD 0.09, 95% CI 0.08 to 0.10, p < 0.00001). The DFP-DFO combination therapy was more efficacious than DFP or DFO monotherapy in improving cardiac ejection fraction (MD 5.67, 95% CI 1.32 to 10.02, p = 0.008). There was no significant difference in all other outcomes examined. Meta-analysis on changes in myocardial iron content was not possible due to differences in data presentation. The quality of evidence for all outcomes was low. There is currently insufficient evidence to show that DFP is superior to DFO in the treatment of iron overload. The use of DFP must be weighed against the potential side-effects, patient compliance and preference. Large RCTs with clinically relevant outcomes are required.
Topics: Blood Transfusion; Deferiprone; Deferoxamine; Female; Humans; Iron Chelating Agents; Iron Overload; Male; Pyridones; beta-Thalassemia
PubMed: 25307964
DOI: 10.3109/03630269.2014.965781 -
The Cochrane Database of Systematic... Aug 2013Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through red blood cell... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through red blood cell transfusions.Repeated transfusions result in an excessive accumulation of iron in the body (iron overload), removal of which is achieved through iron chelation therapy. A commonly used iron chelator, deferiprone, has been found to be pharmacologically efficacious. However, important questions exist about the efficacy and safety of deferiprone compared to another iron chelator, desferrioxamine.
OBJECTIVES
To summarise data from trials on the clinical efficacy and safety of deferiprone and to compare the clinical efficacy and safety of deferiprone with desferrioxamine for thalassaemia.
SEARCH METHODS
We searched the Cochrane Cystic fibrosis and Genetic Disorders Group's Haemoglobinopathies trials Register and MEDLINE, EMBASE, CENTRAL (The Cochrane Library), LILACS and other international medical databases, plus registers of ongoing trials and the Transfusion Evidence Library (www.transfusionevidencelibrary.com). We also contacted the manufacturers of deferiprone and desferrioxamine.All searches were updated to 05 March 2013.
SELECTION CRITERIA
Randomised controlled trials comparing deferiprone with another iron chelator; or comparing two schedules or doses of deferiprone, in people with transfusion-dependent thalassaemia.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed trials for risk of bias and extracted data. Missing data were requested from the original investigators.
MAIN RESULTS
A total of 17 trials involving 1061 participants (range 13 to 213 participants per trial) were included. Of these, 16 trials compared either deferiprone alone with desferrioxamine alone, or a combined therapy of deferiprone and desferrioxamine with either deferiprone alone or desferrioxamine alone; one compared different schedules of deferiprone. There was little consistency between outcomes and limited information to fully assess the risk of bias of most of the included trials.Four trials reported mortality; each reported the death of one individual receiving deferiprone with or without desferrioxamine. One trial reported five further deaths in patients who withdrew from randomised treatment (deferiprone with or without desferrioxamine) and switched to desferrioxamine alone. Seven trials reported cardiac function or liver fibrosis as measures of end organ damage.Earlier trials measuring the cardiac iron load indirectly by magnetic resonance imaging (MRI) T2* signal had suggested deferiprone may reduce cardiac iron more quickly than desferrioxamine. However, a meta-analysis of two trials suggested that left ventricular ejection fraction was significantly reduced in patients who received desferrioxamine alone compared with combination therapy. One trial, which planned five years of follow up, was stopped early due to the beneficial effects of combined treatment compared with deferiprone alone in terms of serum ferritin levels reduction.The results of this and three other trials suggest an advantage of combined therapy over monotherapy to reduce iron stores as measured by serum ferritin. There is, however, no conclusive or consistent evidence for the improved efficacy of combined deferiprone and desferrioxamine therapy over monotherapy from direct or indirect measures of liver iron. Both deferiprone and desferrioxamine produce a significant reduction in iron stores in transfusion-dependent, iron-overloaded people. There is no evidence from randomised controlled trials to suggest that either has a greater reduction of clinically significant end organ damage.Evidence of adverse events were observed in all treatment groups. Occurrence of any adverse event was significantly more likely with deferiprone than desferrioxamine in one trial, RR 2.24 (95% CI 1.19 to 4.23). Meta-analysis of a further two trials showed a significant increased risk of adverse events associated with combined deferiprone and desferrioxamine compared with desferrioxamine alone, RR 3.04 (95% CI 1.18 to 7.83). The most commonly reported adverse event was joint pain, which occurred significantly more frequently in patients receiving deferiprone than desferrioxamine, RR 2.64 (95% CI 1.21 to 5.77). Other common adverse events included gastrointestinal disturbances as well as neutropenia or leucopenia, or both.
AUTHORS' CONCLUSIONS
In the absence of data from randomised controlled trials, there is no evidence to suggest the need for a change in current treatment recommendations; namely that deferiprone is indicated for treating iron overload in people with thalassaemia major when desferrioxamine is contraindicated or inadequate. Intensified desferrioxamine treatment (by either subcutaneous or intravenous route) or use of other oral iron chelators, or both, remains the established treatment to reverse cardiac dysfunction due to iron overload. Indeed, the US Food and Drug Administration (FDA) recently only gave support for deferiprone to be used as a last resort for treating iron overload in thalassaemia, myelodysplasia and sickle cell disease. However, there is evidence that adverse events are increased in patients treated with deferiprone compared with desferrioxamine and in patients treated with combined deferiprone and desferrioxamine compared with desferrioxamine alone. There is an urgent need for adequately-powered, high-quality trials comparing the overall clinical efficacy and long-term outcome of deferiprone with desferrioxamine.
Topics: Administration, Oral; Chelation Therapy; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Pyridones; Randomized Controlled Trials as Topic; Thalassemia; Treatment Outcome
PubMed: 23966105
DOI: 10.1002/14651858.CD004839.pub3 -
The Cochrane Database of Systematic... Aug 2013Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through red blood cell... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through red blood cell transfusions.Repeated transfusions result in an excessive accumulation of iron in the body (iron overload), removal of which is achieved through iron chelation therapy. Desferrioxamine mesylate (desferrioxamine) is one of the most widely used iron chelators. Substantial data have shown the beneficial effects of desferrioxamine, although adherence to desferrioxamine therapy is a challenge. Alternative oral iron chelators, deferiprone and deferasirox, are now commonly used. Important questions exist about whether desferrioxamine, as monotherapy or in combination with an oral iron chelator, is the best treatment for iron chelation therapy.
OBJECTIVES
To determine the effectiveness (dose and method of administration) of desferrioxamine in people with transfusion-dependent thalassaemia.To summarise data from trials on the clinical efficacy and safety of desferrioxamine for thalassaemia and to compare these with deferiprone and deferasirox.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We also searched MEDLINE, EMBASE, CENTRAL (The Cochrane Library), LILACS and other international medical databases, plus ongoing trials registers and the Transfusion Evidence Library (www.transfusionevidencelibrary.com). All searches were updated to 5 March 2013.
SELECTION CRITERIA
Randomised controlled trials comparing desferrioxamine with placebo, with another iron chelator, or comparing two schedules or doses of desferrioxamine, in people with transfusion-dependent thalassaemia.
DATA COLLECTION AND ANALYSIS
Six authors working independently were involved in trial quality assessment and data extraction. For one trial, investigators supplied additional data upon request.
MAIN RESULTS
A total of 22 trials involving 2187 participants (range 11 to 586 people) were included. These trials included eight comparisons between desferrioxamine alone and deferiprone alone; five comparisons between desferrioxamine combined with deferiprone and deferiprone alone; eight comparisons between desferrioxamine alone and desferrioxamine combined with deferiprone; two comparisons of desferrioxamine with deferasirox; and two comparisons of different routes of desferrioxamine administration (bolus versus continuous infusion). Overall, few trials measured the same or long-term outcomes. Seven trials reported cardiac function or liver fibrosis as measures of end organ damage; none of these included a comparison with deferasirox.Five trials reported a total of seven deaths; three in patients who received desferrioxamine alone, two in patients who received desferrioxamine and deferiprone. A further death occurred in a patient who received deferiprone in another who received deferasirox alone. One trial reported five further deaths in patients who withdrew from randomised treatment (deferiprone with or without desferrioxamine) and switched to desferrioxamine alone.One trial planned five years of follow up but was stopped early due to the beneficial effects of a reduction in serum ferritin levels in those receiving combined desferrioxamine and deferiprone treatment compared with deferiprone alone. The results of this and three other trials suggest an advantage of combined therapy with desferrioxamine and deferiprone over monotherapy to reduce iron stores as measured by serum ferritin. There is, however, no evidence for the improved efficacy of combined desferrioxamine and deferiprone therapy against monotherapy from direct or indirect measures of liver iron.Earlier trials measuring the cardiac iron load indirectly by measurement of the magnetic resonance imaging T2* signal had suggested deferiprone may reduce cardiac iron more quickly than desferrioxamine. However, meta-analysis of two trials showed a significantly lower left ventricular ejection fraction in patients who received desferrioxamine alone compared with those who received combination therapy using desferrioxamine with deferiprone.Adverse events were recorded by 18 trials. These occurred with all treatments, but were significantly less likely with desferrioxamine than deferiprone in one trial, relative risk 0.45 (95% confidence interval 0.24 to 0.84) and significantly less likely with desferrioxamine alone than desferrioxamine combined with deferiprone in two other trials, relative risk 0.33 (95% confidence interval 0.13 to 0.84). In particular, four studies reported permanent treatment withdrawal due to adverse events from deferiprone; only one of these reported permanent withdrawals associated with desferrioxamine. Adverse events also occurred at a higher frequency in patients who received deferasirox than desferrioxamine in one trial. Eight trials reported local adverse reactions at the site of desferrioxamine infusion including pain and swelling. Adverse events associated with deferiprone included joint pain, gastrointestinal disturbance, increases in liver enzymes and neutropenia; adverse events associated with deferasirox comprised increases in liver enzymes and renal impairment. Regular monitoring of white cell counts has been recommended for deferiprone and monitoring of liver and renal function for deferasirox.In summary, desferrioxamine and the oral iron chelators deferiprone and deferasirox produce significant reductions in iron stores in transfusion-dependent, iron-overloaded people. There is no evidence from randomised clinical trials to suggest that any one of these has a greater reduction of clinically significant end organ damage, although in two trials, combination therapy with desferrioxamine and deferiprone showed a greater improvement in left ventricular ejection fraction than desferrioxamine used alone.
AUTHORS' CONCLUSIONS
Desferrioxamine is the recommended first-line therapy for iron overload in people with thalassaemia major and deferiprone or deferasirox are indicated for treating iron overload when desferrioxamine is contraindicated or inadequate. Oral deferasirox has been licensed for use in children aged over six years who receive frequent blood transfusions and in children aged two to five years who receive infrequent blood transfusions. In the absence of randomised controlled trials with long-term follow up, there is no compelling evidence to change this conclusion.Worsening iron deposition in the myocardium in patients receiving desferrioxamine alone would suggest a change of therapy by intensification of desferrioxamine treatment or the use of desferrioxamine and deferiprone combination therapy.Adverse events are increased in patients treated with deferiprone compared with desferrioxamine and in patients treated with combined deferiprone and desferrioxamine compared with desferrioxamine alone. People treated with all chelators must be kept under close medical supervision and treatment with deferiprone or deferasirox requires regular monitoring of neutrophil counts or renal function respectively. There is an urgent need for adequately-powered, high-quality trials comparing the overall clinical efficacy and long-term outcomes of deferiprone, deferasirox and desferrioxamine.
Topics: Benzoates; Chelation Therapy; Deferasirox; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Pyridones; Randomized Controlled Trials as Topic; Siderophores; Thalassemia; Transfusion Reaction; Triazoles
PubMed: 23963793
DOI: 10.1002/14651858.CD004450.pub3 -
The Cochrane Database of Systematic... Feb 2012Thalassemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Benzoates; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Deferasirox; Deferoxamine; Erythrocyte Transfusion; Humans; Iron Chelating Agents; Iron Overload; Randomized Controlled Trials as Topic; Thalassemia; Triazoles
PubMed: 22336831
DOI: 10.1002/14651858.CD007476.pub2 -
Blood Cells, Molecules & Diseases Oct 2011The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences... (Meta-Analysis)
Meta-Analysis Review
The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences with 95% CI, or standardized mean differences. Statistical heterogeneity was tested using χ2 (Q) and I2. Sources of bias and Grading of Recommendations Assessment, Development and Evaluation system (GRADE) were considered. Overall, 1520 patients were included. Only 7.4% of trials were free of bias. Overall measurements suggest low trial quality (GRADE). The meta-analysis suggests lower final liver iron concentrations during associated versus monotherapy treatment (p<0.0001), increases in serum ferritin levels during DFX 5, 10, and 20 mg/kg versus DFO-treated groups (p<0.00001, p<0.00001, and p=0.002, respectively), but no statistically significant difference during DFX 30 mg/kg versus DFO (p=0.70), no statistically significant variations in heart T2* signal during associated or sequential versus mono-therapy treatment (p=0.46 and p=0.14, respectively), increases in urinary iron excretion during associated or sequential versus monotherapy treatment (p=0.008 and p=0.02, respectively), and improved ejection fraction during associated or sequential versus monotherapy treatment (p=0.01 and p<0.00001, respectively). These findings do not support any specific chelation treatment. The literature shows risks of bias, and additional larger and longer trials are needed.
Topics: Benzoates; Chelation Therapy; Deferasirox; Deferiprone; Deferoxamine; Drug Therapy, Combination; Ferritins; Humans; Iron; Iron Chelating Agents; Liver; MEDLINE; Myocardium; Pyridones; Randomized Controlled Trials as Topic; Siderophores; Treatment Outcome; Triazoles; Ventricular Function; beta-Thalassemia
PubMed: 21843958
DOI: 10.1016/j.bcmd.2011.07.002 -
The Cochrane Database of Systematic... Aug 2010Sickle cell disease (SCD) is a group of genetic haemoglobin disorders. Increasingly, some people with SCD develop secondary iron overload due to occasional red blood... (Review)
Review
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.
Topics: Anemia, Sickle Cell; Benzoates; Chelation Therapy; Deferasirox; Deferoxamine; Erythrocyte Transfusion; Ferritins; Humans; Iron Chelating Agents; Iron Overload; Randomized Controlled Trials as Topic; Triazoles
PubMed: 20687088
DOI: 10.1002/14651858.CD007477.pub2 -
Health Technology Assessment... Jan 2009To assess the clinical effectiveness and cost-effectiveness of deferasirox for the treatment of iron overload associated with regular blood transfusions in patients with... (Meta-Analysis)
Meta-Analysis Review
Deferasirox for the treatment of iron overload associated with regular blood transfusions (transfusional haemosiderosis) in patients suffering with chronic anaemia: a systematic review and economic evaluation.
OBJECTIVES
To assess the clinical effectiveness and cost-effectiveness of deferasirox for the treatment of iron overload associated with regular blood transfusions in patients with chronic anaemia such as beta-thalassaemia major (beta-TM) and sickle cell disease (SCD).
DATA SOURCES
Electronic databases were searched up to March 2007.
REVIEW METHODS
Methods followed accepted procedures for conducting and reporting systematic reviews and economic evaluations.
RESULTS
A total of 14 randomised controlled trials (RCTs) involving a study population of 1480 (ranging from 13 to 586) met the inclusion criteria. There was a high degree of heterogeneity between trials in terms of trial design and outcome reporting. As such it was only possible to meta-analyse serum ferritin data from six trials making comparisons between deferiprone and DFO and combination therapy and DFO. Only one of the results was statistically significant, favouring combination therapy over DFO alone for serum ferritin at 12 months. How this translates into iron loading in organs such as the heart is unclear, nor was it possible to determine the long-term benefits of chelation therapy. Eight full economic evaluations (one full paper; seven abstracts) were included in the review. The results were generally consistent and appear to demonstrate the cost-effectiveness of deferasirox compared with DFO for the treatment of iron overload in a number of different patient populations and study locations. However, a number of assumptions and, in the case of the long-term studies, extrapolation from short-term RCT data were required, which render the results highly speculative at best. Because of the paucity of long-term data we developed a simple, short-term (1 year) model to assess the costs and benefits of deferasirox, deferiprone and DFO in patients with beta-TM and SCD from an NHS perspective. A number of assumptions were required to generate results and, as such, they should be interpreted as indicative rather than factual. Our model suggests that deferasirox may be a cost-effective strategy compared with DFO, at a cost per quality-adjusted life-year (QALY) below 30,000 pounds per year, for patients with beta-TM and SCD. However, this is highly dependent upon the age of the patient and the use and benefits of balloon infusers to administer DFO. Deferasirox compared with deferiprone is likely to be cost-effective only for young children. Furthermore, if deferiprone is proven to offer the same health benefits as deferasirox, the latter will not be cost-effective for any patient compared with deferiprone.
CONCLUSIONS
In the short term there is little clinical difference between any of the three chelators in terms of removing iron from the blood and liver. Deferasirox may be cost-effective compared with DFO in patients with beta-TM and SCD, but it is unlikely to be cost-effective compared with deferiprone. Elucidating the long-term benefits of chelation therapy, including issues of adverse events and adherence, should be the primary focus for future research. Future work should aim for consistency and transparency in reporting study design and results to aid decision-making when making comparisons across trials.
Topics: Anemia; Benzoates; Chronic Disease; Contraindications; Cost-Benefit Analysis; Deferasirox; Deferiprone; Deferoxamine; Drug Therapy, Combination; Hemosiderosis; Humans; Iron Chelating Agents; Pyridones; Randomized Controlled Trials as Topic; Technology Assessment, Biomedical; Transfusion Reaction; Treatment Outcome; Triazoles
PubMed: 19068191
DOI: 10.3310/hta13010