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Mediterranean Journal of Hematology and... 2019Deferoxamine (DFO) or Deferiprone (DFP) or Deferasirox (DFX) monotherapy and DFO and DFP combination therapy (DFO+DFP) were four commonly implemented now chelation... (Review)
Review
BACKGROUND
Deferoxamine (DFO) or Deferiprone (DFP) or Deferasirox (DFX) monotherapy and DFO and DFP combination therapy (DFO+DFP) were four commonly implemented now chelation regimens for the iron overloaded of β-thalassemia major. This systematic review aims to determine the cost-effectiveness of four chelation regimens and provide evidence for the rational use of chelation regimens for β-thalassemia major therapy in the clinic.
METHODS
A systematic literature search in MEDLINE, EMBASE, the Cochrane Library, China Biology Medicine, China National Knowledge Infrastructure, VIP Data, and WanFang Data was conducted in April 2018. In addition, a manual search was performed. Two researchers, working independently, selected the papers, extracted the data, and assessed the methodological quality of the included documents. Each included paper was evaluated using a checklist developed by Drummond .
RESULTS
The number of records was initially 968, and eight papers met the final eligibility criteria. All the included eight papers were cost-utility analyses, and their methodological quality was fair. In these eight papers, nineteen studies were present. Nine studies of DFX versus DFO had contradictory results. Out of the nineteen studies, three studies of DFX versus DFP established that using DFP was cost-effective. Three studies of DFP versus DFO proved that using DFP was cost-effective. One survey of DFO+DFP versus DFO found that using DFO was cost-effective. One study of DFO+DFP versus DFP found that using DFP was cost-effective. Moreover, there were two studies of DFO+DFP versus DFX, but we cannot be sure which one of two chelation regimens was cost-effective.
CONCLUSION
In brief, DFP is cost-effective, followed by DFO or DFX, when an iron chelator is to be used alone for β-thalassemia iron overload treatment. All studies that compared DFO+DFP with DFO (or DFP) monotherapy established that the DFO+DFP was not cost-effective. Existing studies about DFO+DFP versus DFX could not prove which one of two chelation regimens was cost-effective. However, due to the low number of DFO+DFP versus DFO (or DFP or DFX) monotherapy studies, more extensive, high-quality research is required for further analysis and confirmation of our findings. Moreover, the cost-effectiveness is not an absolute issue when in different countries (regions) the results are opposite for other countries (regions). As a result, the local/national context had a substantial influence on the results of the pharmacoeconomic evaluation.
PubMed: 31308912
DOI: 10.4084/MJHID.2019.036 -
The Cochrane Database of Systematic... May 2018Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia (who are transfusion-dependent or non-transfusion-dependent) are at risk of iron... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Adolescent; Adult; Anemia, Sickle Cell; Benzoates; Chelation Therapy; Child; Deferasirox; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Patient Compliance; Pyridones; Quality of Life; Randomized Controlled Trials as Topic; Triazoles; beta-Thalassemia
PubMed: 29737522
DOI: 10.1002/14651858.CD012349.pub2 -
The Cochrane Database of Systematic... Nov 2010The myelodysplastic syndrome (MDS) comprises a diverse group of haematopoietic stem cell disorders. Due to symptomatic anaemia most patients require supportive therapy... (Review)
Review
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.
Topics: Benzoates; Chelation Therapy; Deferasirox; Humans; Iron Chelating Agents; Iron Overload; Myelodysplastic Syndromes; Triazoles
PubMed: 21069694
DOI: 10.1002/14651858.CD007461.pub2 -
Hemoglobin Jun 2010Good adherence to iron chelation therapy in thalassemia is crucial. Although there is evidence that adherence is related to regimen factors, there has been less emphasis... (Meta-Analysis)
Meta-Analysis Review
Good adherence to iron chelation therapy in thalassemia is crucial. Although there is evidence that adherence is related to regimen factors, there has been less emphasis on the relationship between psychosocial (psychological, demographic and social) factors and adherence. We present a systematic review of psychosocial correlates of chelation adherence in thalassemia. Nine studies met the inclusion criteria. Information was extracted regarding the study characteristics and the relationship between psychosocial factors and chelation adherence. Methodological quality was rated. The studies took place in a range of countries, were mostly cross sectional in design, and examined adherence to deferoxamine (DFO) only. Sample sizes ranged from 15 to 1573. A variety of psychosocial variables were examined. Definitions of adherence varied between studies and non adherence rates were also variable (9 to 66%). Older age was consistently associated with lower levels of chelation adherence. There were few other consistent findings. The methodological quality of studies was variable. There is a need for more methodologically sophisticated and theoretically informed studies on psychosocial correlates of chelation adherence. We offer specific suggestions.
Topics: Chelation Therapy; Demography; Humans; Iron Chelating Agents; Medication Adherence; Thalassemia
PubMed: 20524820
DOI: 10.3109/03630269.2010.485080 -
The Cochrane Database of Systematic... Jul 2007Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through transfusions of red... (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 transfusions of red blood cells. Repeated transfusions result in 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 for thalassaemia with desferrioxamine.
SEARCH STRATEGY
We searched the Group's Haemoglobinopathies Trials Register, MEDLINE, EMBASE, Biological Abstracts, ZETOC, Current Controlled Trials and bibliographies of relevant publications. We contacted the manufacturers of deferiprone and desferrioxamine. Most recent searches: June 2006.
SELECTION CRITERIA
Randomised controlled trials comparing deferiprone with another iron chelator; or comparing two schedules of deferiprone, in people with transfusion-dependent thalassaemia.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed trial quality and extracted data. Missing data were requested from the original investigators.
MAIN RESULTS
Ten trials involving 398 people (range 10 to 144 people) were included. Nine trials compared deferiprone with desferrioxamine or a combination of deferiprone and desferrioxamine and one compared different schedules of deferiprone. There was little consistency between outcomes and little information to fully assess the methodological quality of most of the included trials. No trial reported long-term outcomes (mortality and end organ damage). There was no consistent effect on reduction of iron overload between all treatment comparisons, with the exception of urinary iron excretion in comparisons of deferiprone with desferrioxamine. An increase in iron excretion levels favoured deferiprone in one trial and desferrioxamine in three trials, even though measurement of urinary iron excretion underestimates total iron excretion by desferrioxamine.Adverse events were recorded in trials comparing deferiprone with desferrioxamine. There was evidence of adverse events in all treatment groups. Adverse events in one trial were significantly more likely with deferiprone than desferrioxamine, relative risk 2.24 (95% confidence interval 1.19 to 4.23).
AUTHORS' CONCLUSIONS
We found no reason to change current treatment recommendations, namely deferiprone is indicated for treating iron overload in people with thalassaemia major when desferrioxamine is contraindicated or inadequate. However, 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: Chelation Therapy; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Pyridones; Randomized Controlled Trials as Topic; Thalassemia; Treatment Outcome
PubMed: 17636775
DOI: 10.1002/14651858.CD004839.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 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 -
Tropical Medicine & International... Nov 2005Randomized controlled clinical trials (RCTs) of adjunctive treatment to reduce the high-mortality associated with cerebral malaria (CM) have so far failed to show any... (Review)
Review
BACKGROUND
Randomized controlled clinical trials (RCTs) of adjunctive treatment to reduce the high-mortality associated with cerebral malaria (CM) have so far failed to show any benefit. This may be due in part to improperly designed and/or conducted trials. Therefore a systematic review of quality of RCTs for the treatment of CM with mortality as either primary or secondary outcome published between 1980 and 2000, was conducted.
METHODS
RCTs from the peer-reviewed literature using electronic searches. Methodological quality was assessed using an individual component approach (adequacy of concealment of allocation schedule, generation of allocation sequence, double blinding and analysis of participant as randomized). Sample sizes were recalculated for the ability of reviewed trials to detect 25% and 50% reductions in mortality.
RESULTS
Nine trials satisfied the inclusion criteria and were reviewed. Only two had sufficient power to detect a 50% reduction in mortality, and none could detect a 25% reduction. All the trials had inadequate methodological quality in one or more of the components, although in two trials these deficiencies were few.
CONCLUSION
There is a need for researchers and donors to ensure proper planning and implementation of RCTs in developing countries. In CM, demonstration of worthwhile reduction in mortality by a single intervention will require a large number of subjects, which a single centre may not be able to recruit.
Topics: Anticonvulsants; Deferoxamine; Dexamethasone; Double-Blind Method; Enzyme Inhibitors; Humans; Malaria, Cerebral; Pentoxifylline; Phenobarbital; Randomized Controlled Trials as Topic; Sample Size; Siderophores; Tumor Necrosis Factor-alpha
PubMed: 16262742
DOI: 10.1111/j.1365-3156.2005.01505.x -
The Cochrane Database of Systematic... Oct 2005Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through transfusions of red... (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 transfusions of red blood cells. Repeated transfusions results in excessive accumulation of iron in the body (iron overload), removal of which is achieved through iron chelation therapy. Desferrioxamine is the most widely used iron chelator. Substantial data have shown the beneficial effects of desferrioxamine. However, important questions exist about whether desferrioxamine is the best schedule for iron chelation therapy.
OBJECTIVES
To determine the effectiveness (dose and method of administration) of desferrioxamine in people with transfusion-dependent thalassaemia.
SEARCH STRATEGY
We searched the Cochrane Haemoglobinopathies Trials Register, MEDLINE, EMBASE, ZETOC, Current Controlled Trials and bibliographies of relevant publications. We also contacted the manufacturers of desferrioxamine and other iron chelators. Date of last searches: April 2004.
SELECTION CRITERIA
Randomised controlled trials comparing desferrioxamine with placebo; with another iron chelator; or comparing two schedules of desferrioxamine, in people with transfusion-dependent thalassaemia.
DATA COLLECTION AND ANALYSIS
Four authors working independently, were involved in trial quality assessment and data extraction. Missing data were requested from the original investigators.
MAIN RESULTS
Eight trials involving 334 people (range 20 to 144 people) were included. One trial compared desferrioxamine with placebo, five compared desferrioxamine with another iron chelator (deferiprone) and two compared different schedules of desferrioxamine. Overall, few trials measured the same outcomes.Compared to placebo, desferrioxamine significantly reduced iron overload. The number of deaths at 12 years follow up and evidence of reduced end-organ damage was less for desferrioxamine than placebo. When desferrioxamine was compared to deferiprone or a different desferrioxamine schedule there were no statistically significant differences in measures of iron overload. Compliance was recorded by two trials. Compliance was less for desferrioxamine than deferiprone in one trial and of no difference in comparison with desferrioxamine and deferiprone combined with a second trial. Adverse events were recorded in trials comparing desferrioxamine with other iron chelators. There was evidence of adverse events in all treatment groups. In one trial, adverse events were significantly less likely with desferrioxamine than deferiprone, relative risk 0.45 (95% confidence interval 0.24 to 0.84). Assessment of the methodological quality of included trials was not possible, given the general absence of these data in the trials.
AUTHORS' CONCLUSIONS
We found no reason to change current treatment recommendations. However, considerable uncertainty continues to exist about the optimal schedule for desferrioxamine in people with transfusion-dependent thalassaemia.
Topics: Chelation Therapy; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Pyridones; Randomized Controlled Trials as Topic; Thalassemia; Transfusion Reaction
PubMed: 16235363
DOI: 10.1002/14651858.CD004450.pub2 -
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