Deferasirox is a once-daily, oral iron chelator that is widely used in the management of patients with transfusional hemosiderosis. Several Phase II trials along with their respective extension studies as well as a Phase III trial have established the efficacy and safety of this novel agent in transfusion-dependent patients with β-thalassemia, sickle-cell disease and bone marrow-failure syndromes, including myelodysplastic syndrome and aplastic anemia. Data from various clinical trials show that a deferasirox dose of 20 mg/kg/day stabilizes serum ferritin levels and liver iron concentration, while a dose of 30–40 mg/kg/day reduces these parameters and achieves negative iron balance in red cell transfusion-dependent patients with iron overload. Across various pivotal clinical trials, deferasirox was well tolerated, with the most common adverse events being gastrointestinal disturbances, skin rash, nonprogressive increases in serum creatinine, and elevations in liver enzyme levels. Longer-term extension studies have also confirmed the efficacy and safety of deferasirox. However, it is essential that patients on deferasirox therapy are monitored regularly to ensure timely management for any adverse events that may occur with long-term therapy.
deferasirox; iron overload; thalassemia; sickle-cell disease; myelodysplastic syndrome
Purpose of review
Mucormycosis is an increasingly common fungal infection with an unacceptably high mortality despite first-line antifungal therapy. Iron acquisition is a critical step in the causative organsisms’ pathogenetic mechanism. Therefore, abrogation of fungal iron acquisition is a promising therapeutic strategy to impact clinical outcomes for this deadly disease.
The increased risk of mucormycosis in patients in renal failure receiving deferoxamine iron chelation therapy is explained by the fact that deferoxamine actually acts as a siderophore for the agents of mucormycosis, supplying previously unavailable iron to the fungi. The iron liberated from deferoxamine is likely transported into the fungus by the high affinity iron permease. In contrast, two other iron chelators, deferiprone and deferasirox, do not supply iron to the fungus and were shown to be cidal against Zygomycetes in vitro. Further, both iron chelators were shown to effectively treat mucormycosis in animal models, and one has been successfully used as salvage therapy for a patient with rhinocerebral mucormycosis.
Further investigation and development of iron chelators is warranted as adjunctive therapy for mucormycosis.
Mucormycosis; Rhizopus; Iron chelation; Deferasirox; deferiprone
Increased bone marrow iron levels in patients with haematological malignancies is an independent risk factor for developing invasive pulmonary aspergillosis (IPA), suggesting an important role for iron uptake in the pathogenesis of IPA. We sought to determine the potential for combination therapy with the iron chelator deferasirox + liposomal amphotericin B (LAmB) to improve the outcome of murine IPA compared with LAmB monotherapy.
In vitro MIC and minimum fungicidal concentration (MFC) values of the iron chelator, deferasirox, for Aspergillus fumigatus were determined by microdilution assay. In addition, we studied the efficacy of deferasirox alone or combined with LAmB in treating immunocompromised mice infected with A. fumigatus via inhalation.
Deferasirox was cidal in vitro against A. fumigatus, with an MIC and MFC of 25 and 50 mg/L, respectively. Deferasirox monotherapy modestly prolonged survival of mice with IPA. Combination deferasirox + LAmB therapy synergistically improved survival and reduced lung fungal burden compared with either monotherapy alone.
Iron chelation therapy with deferasirox alone or in combination with LAmB is effective in treating experimental IPA. Further study of deferasirox is warranted as adjunctive therapy for IPA infections.
Aspergillus fumigatus; LAmB; IPA
The prognosis of acute myeloid leukemia (AML) in elderly (≥65 years) patients is poor and treatment remains non-consensual especially for those who are not eligible for intensive therapies. Our group has shown that in vitro the iron chelator deferasirox (DFX) synergizes with vitamin D (VD) to promote monocyte differentiation in primary AML cells. Herein, we present results from a retrospective case-control study in which the association of DFX (1–2 g/d) and 25-hydroxycholecalciferol (100,000 IU/week) (DFX/VD) was proposed to patients following demethylating agents failure. Median survival of patients treated with DFX/VD combination (n = 17) was significantly increased in comparison with matched patients receiving best supportive care (BSC) alone (n = 13) (10.4 versus 4 months respectively). In addition, the only factor associated to an increased overall survival in DFX/VD-treated patients was serum VD levels. We conclude that DFX/VD treatment correlated with increased overall survival of AML patients in this retrospective cohort of elderly patients.
Mucormycosis causes mortality in at least 50% of cases despite current first-line therapies. Clinical and animal data indicate that the presence of elevated available serum iron predisposes the host to mucormycosis. Here we demonstrate that deferasirox, an iron chelator recently approved for use in humans by the US FDA, is a highly effective treatment for mucormycosis. Deferasirox effectively chelated iron from Rhizopus oryzae and demonstrated cidal activity in vitro against 28 of 29 clinical isolates of Mucorales at concentrations well below clinically achievable serum levels. When administered to diabetic ketoacidotic or neutropenic mice with mucormycosis, deferasirox significantly improved survival and decreased tissue fungal burden, with an efficacy similar to that of liposomal amphotericin B. Deferasirox treatment also enhanced the host inflammatory response to mucormycosis. Most importantly, deferasirox synergistically improved survival and reduced tissue fungal burden when combined with liposomal amphotericin B. These data support clinical investigation of adjunctive deferasirox therapy to improve the poor outcomes of mucormycosis with current therapy. As iron availability is integral to the pathogenesis of other infections (e.g., tuberculosis, malaria), broader investigation of deferasirox as an antiinfective treatment is warranted.
Patients with non-transfusion-dependent thalassemia (NTDT) often develop iron overload that requires chelation to levels below the threshold associated with complications. This can take several years in patients with high iron burden, highlighting the value of long-term chelation data. Here, we report the 1-year extension of the THALASSA trial assessing deferasirox in NTDT; patients continued with deferasirox or crossed from placebo to deferasirox. Of 133 patients entering extension, 130 completed. Liver iron concentration (LIC) continued to decrease with deferasirox over 2 years; mean change was −7.14 mg Fe/g dry weight (dw) (mean dose 9.8 ± 3.6 mg/kg/day). In patients originally randomized to placebo, whose LIC had increased by the end of the core study, LIC decreased in the extension with deferasirox with a mean change of −6.66 mg Fe/g dw (baseline to month 24; mean dose in extension 13.7 ± 4.6 mg/kg/day). Of 166 patients enrolled, 64 (38.6 %) and 24 (14.5 %) patients achieved LIC <5 and <3 mg Fe/g dw by the end of the study, respectively. Mean LIC reduction was greatest in patients with the highest pretreatment LIC. Deferasirox progressively decreases iron overload over 2 years in NTDT patients with both low and high LIC. Safety profile of deferasirox over 2 years was consistent with that in the core study.
Electronic supplementary material
The online version of this article (doi:10.1007/s00277-013-1808-z) contains supplementary material, which is available to authorized users.
Iron overload; Iron chelation; Non-transfusion-dependent thalassemia; Deferasirox
Duodenal ulcer perforation in pediatric age group is an uncommon entity; hence, it is not usually considered in the differential diagnosis of acute abdomen in these patients. It is important for the emergency physician to consider perforated peptic ulcer in the differential diagnosis of children presenting with acute abdominal pain, gastrointestinal bleeding, or shock. We report a 6½-year-old male child with thalassemia major who presented to emergency room with an acute abdomen and shock, who was subsequently found to have a perforated duodenal ulcer, probably related to use of oral chelating agent, deferasirox. Although, gastrointestinal symptoms like nausea, vomiting, and abdominal pain has been mentioned as infrequent adverse event in the scientific product information of deferasirox, in our current knowledge this is the first case report of perforated duodenal ulcer after oral deferasirox. The severity of this event justifies the reporting of this case. This patient had an atypical presentation in that there were no signs or symptoms of peptic ulcer disease before perforation and shock he was successfully managed with open surgery after initial resuscitation and stabilization of his general condition.
Chelating agent; deferasirox; duodenal perforation
Host iron availability is fundamental to mucormycosis pathogenesis. The combination of liposomal amphotericin B (LAmB) and deferasirox iron chelation therapy synergistically improved survival in diabetic mice with mucormycosis. To determine the safety of combination deferasirox plus LAmB therapy for mucormycosis, a multicentred, placebo-controlled, double-blinded clinical trial was conducted.
Twenty patients with proven or probable mucormycosis were randomized to receive treatment with LAmB plus deferasirox (20 mg/kg/day for 14 days) or LAmB plus placebo (NCT00419770, clinicaltrials.gov). The primary analyses were for safety and exploratory efficacy.
Patients in the deferasirox arm (n = 11) were more likely than those in the placebo arm (n = 9) to have active malignancy, neutropenia and corticosteroid therapy, and were less likely to receive concurrent non-study antifungal therapy. Reported adverse events and serious adverse events were similar between the groups. However, death was more frequent in the deferasirox than in the placebo arm at 30 days (45% versus 11%, P = 0.1) and 90 days (82% versus 22%, P = 0.01). Global success (alive, clinically stable, radiographically improved) for the deferasirox arm versus the placebo arm at 30 and 90 days, respectively, was 18% (2/11) versus 67% (6/9) (P = 0.06) and 18% (2/11) versus 56% (5/9) (P = 0.2).
Patients with mucormycosis treated with deferasirox had a higher mortality rate at 90 days. Population imbalances in this small Phase II study make generalizable conclusions difficult. Nevertheless, these data do not support a role for initial, adjunctive deferasirox therapy for mucormycosis.
antifungal; fungal infections; mould infections; combination therapy
Iron chelating agents have the potential to minimize damage associated with oxidative stress in a range of diseases; however, this potential is countered by risks of indiscriminant metal binding or iron depletion in conditions not associated with systemic iron overload. Deferasirox is a chelator used clinically for iron overload, but also is cytotoxic to cells in culture. In order to test whether a prodrug version of deferasirox could minimize its cytotoxicity but retain its protective properties against iron-induced oxidative damage, we synthesized a prochelator that contains a self-immolative boronic ester masking group that is removed upon exposure to hydrogen peroxide to release the bis-hydroxyphenyltriazole ligand deferasirox. We present here the synthesis and characterization of this triazole-based, self-immolative prochelator: TIP (4-(5-(2-((4-boronobenzyl)oxy)phenyl)-3-(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl)benzoic acid). TIP does not coordinate to Fe3+ and shows only weak affinity for Cu2+ or Zn2+, in stark contrast to deferasirox, which avidly binds all three metal ions. TIP converts efficiently in vitro upon reaction with hydrogen peroxide to deferasirox. In cell culture, TIP protects retinal pigment epithelial cells from death induced by hydrogen peroxide; however, TIP itself is more cytotoxic than deferasirox in unstressed cells. These results imply that the cytotoxicity of deferasirox may not derive exclusively from its iron withholding properties.
Chelation therapy; Iron; Oxidative stress; Fenton chemistry; Reactive oxygen species; Prodrug
Zygomycosis are invasive mould infections, rarely diagnosed in hematologic patients. Most of the cases published are in patients with prolonged neutropenia, along with other risk factors such as the use of prior broad-spectrum antibiotics (including new antifungal agents, such as voriconazole), diabetes mellitus (with or without ketoacidosis), malnutrition, iron overload (with or without the use of deferoxamine). These infections have poor prognosis due to the involvement of vital anatomic structures and late diagnosis. Until recent years, the treatment was based on high doses of amphotericin B plus surgical debridement. Here we present two patients with hematologic diseases (one with leukemia, the second with aplastic anemia) with an impaired immune system and the diagnosis of zygomycosis. The survival of one of them was mainly due to early diagnosis and surgical debridement; unfortunately the second was misdiagnosed as an extensive ecchymosis due to thrombocytopenia and died with CNS involvement.
Beta thalassemia is an inherited hemoglobin disorder resulting in a severe, chronic anemia requiring life-long blood transfusion that induces iron overload. Silymarin is a flavonoid complex isolated from Silybin marianum with a strong antioxidant activity, inducing an hepatoprotective action, and probably, a protective effect on iron overload. The aim of this work was to determine the silymarin value in improving iron chelation in thalassemic patients with iron overload treated with Deferasirox.
Patients and Methods
This study was conducted on 40 children with beta thalassemia major under follow-up at Hematology Unit, Pediatric Department, Tanta University Hospital with serum ferritin level more than 1000 ng/ml and was divided into two groups. Group IA: Received oral Deferasirox (Exjade) and silymarin for 6 months. Group IB: Received oral Deferasirox (Exjade) and placebo for 6 months and 20 healthy children serving as a control group in the period between April 2011 and August 2012 and was performed after approval from research ethical committee center in Tanta University Hospital and obtaining an informed written parental consent from all participants in this study.
Serum ferritin levels were markedly decreased in group IA cases compared with group IB (P= 0.001).
From this study we concluded that, silymarin in combination with Exjade can be safely used in the treatment of iron-loaded thalassemic patients as it showed good iron chelation with no sign of toxicity.
We recommend extensive multicenter studies in a large number of patients with longer duration of follow-up and more advanced techniques of assessment of iron status in order to clarify the exact role of silymarin in reducing iron overload in children with beta thalassemia.
Available iron chelation regimes in thalassaemia may achieve different changes in cardiac and hepatic iron as assessed by MR. The aim of this study was to assess the efficacy of four available iron chelator regimes in 232 thalassaemia major patients by assessing the rate of change in repeated measurements of cardiac and hepatic MR.
For the heart, deferiprone and the combination of deferiprone and deferoxamine significantly reduced cardiac iron at all levels of iron loading. As patients were on deferasirox for a shorter time, a second analysis ("Initial interval analysis") assessing the change between the first two recorded MR results for both cardiac and hepatic iron (minimum interval 12 months) was made. Combination therapy achieved the most rapid fall in cardiac iron load at all levels and deferiprone alone was significantly effective with moderate and mild iron load. In the liver, deferasirox effected significant falls in iron load and combination therapy resulted in the most rapid decline.
With the knowledge of the efficacy of the different available regimes and the specific iron load in the heart and the liver, appropriate tailoring of chelation therapy should allow clearance of iron. Combination therapy is best in reducing both cardiac and hepatic iron, while monotherapy with deferiprone or deferasirox are effective in the heart and liver respectively. The outcomes of this study may be useful to physicians as to the chelation they should prescribe according to the levels of iron load found in the heart and liver by MR.
Hereditary hemochromatosis (HH) is characterized by increased intestinal iron absorption that may result in iron overload. Although phlebotomy is widely practiced, it is poorly tolerated or contraindicated in patients with anemias, severe heart disease, or poor venous access, and compliance can vary. The once-daily, oral iron chelator, deferasirox (Exjade) may provide an alternative treatment option. Patients with HH carrying the HFE gene who were homozygous for the Cys282Tyr mutation, serum ferritin levels of 300-2000 ng/mL, transferrin saturation ≥45%, and no known history of cirrhosis were enrolled in this dose-escalation study to characterize the safety and efficacy of deferasirox, comprising a core and an extension phase (each 24 weeks). Forty-nine patients were enrolled and received starting deferasirox doses of 5 (n = 11), 10 (n = 15), or 15 (n = 23) mg/kg/day. Adverse events were generally dose-dependent, the most common being diarrhea, headache, and nausea (n = 18, n = 10, and n = 8 in the core and n = 1, n = 1, and n = 0 in the extension, respectively). More patients in the 15 mg/kg/day than in the 5 or 10 mg/kg/day cohorts experienced increases in alanine aminotransferase and serum creatinine levels during the 48-week treatment period; six patients had alanine aminotransferase >3× baseline and greater than the upper limit of normal range, and eight patients had serum creatinine >33% above baseline and greater than upper limit of normal on two consecutive occasions. After receiving deferasirox for 48 weeks, median serum ferritin levels decreased by 63.5%, 74.8%, and 74.1% in the 5, 10, and 15 mg/kg/day cohorts, respectively. In all cohorts, median serum ferritin decreased to <250 ng/mL. Conclusion: Deferasirox doses of 5, 10, and 15 mg/kg/day can reduce iron burden in patients with HH. Based on the safety and efficacy results, starting deferasirox at 10 mg/kg/day appears to be most appropriate for further study in this patient population. (Hepatology 2010)
Mucormycosis (zygomycosis) is an acute and often fatal opportunistic fungal infection. Predisposing factors in the development of mucormycosis are nonspecific and include hyperglycemia, hematologic malignancies, neutropenia, pharmacologic immunosuppression, solid organ or bone marrow/stem cell transplantation, burns, trauma, malnutrition, and intravenous drug use. Mucormycosis has also been described in patients with iron and aluminum overload, patients on dialysis, and patients receiving iron chelating therapy. We describe a 75-year-old man with myelodysplastic syndrome and iron overload secondary to multiple red blood cell transfusions who had been treated with deferoxamine chelation therapy. He was admitted to the hospital for atrial fibrillation, developed multiple organ failure, and died. Pulmonary invasive mucormycosis was demonstrated at autopsy. This case further documents an association between invasive mucormycosis, iron overload, and deferoxamine therapy.
Cardiac complications because of transfusional iron overload are the main cause of death in thalassaemia major. New chelators and iron monitoring methods such as cardiac magnetic resonance (CMR) became available after the year 2000. We evaluated the impact of these new management options on cardiac mortality and morbidity.
The risk of cardiac death during 1990–1999 and 2000–2008 was compared. Furthermore, after 1999, morbidity, mortality and reversal of heart failure were evaluated according to chelation regime: desferrioxamine (DFO), deferiprone (DFP) and combination therapy of DFO and DFP. We also present preliminary results for deferasirox (DFX), a new oral chelator.
Three hundred and fifty-four patients were included in the de novo cardiac event evaluation, while 86 were included in the improvement component. The annual risk of cardiac death in patients aged between 20–30 and 30–40 reduced from 1.52% to 0.67% and 1.87% to 0.56%, respectively, before and after the year 2000. The risk for a de novo cardiac event for DFO was 9.1 times greater than that of DFP and 23.6 than with the combination of DFP and DFO. For DFX, there was one cardiac event over 269 patient-years. The risk of cardiac death was 9.5 per 1000 patient-years for DFO, 2.5 on DFP, 1.4 on combination. In the DFX group no cardiac deaths were recorded. The odds of improvement were 8.5 times greater with DFP and 6.1 with combination therapy compared to DFO.
The new chelation regimes, together with CMR have contributed significantly to the reduction in cardiac morbidity and mortality in patients with thalassaemia major.
thalassaemia major; cardiac disease; desferrioxamine; deferiprone; deferasirox; transfusional iron overload
Zygomycosis is a difficult to treat and frequently fatal infection affecting immunocompromised and (rarely) immunocompetent patients. It requires a multifaceted approach involving elimination of predisposing factors, surgical debridement, and antifungal therapy.
We report the case of a postrenal transplant patient who developed disseminated zygomycosis with vascular aneurysms after receiving empirical voriconazole treatment for presumed pulmonary fungal infection in addition to immunosuppression and methylprednisolone pulses for presumed graft rejection, as renal biopsy was declined. Initially, liposomal amphotericin therapy in combination with surgical intervention failed. Addition of posaconazole as salvage therapy improved the patient outcome. He received total of 6 weeks of AmBisome and 12 weeks of posaconazole.
Zygomycosis is a difficult to treat infection. Management includes surgical debridement and antifungal therapy, namely liposomal amphotericin. However, in cases where treatment with liposomal amphotericin along with surgical intervention fails, posaconazole can be given as a salvage therapy. Duration of antifungal treatment should be determined on an individual basis.
renopulmonary; zygomycosis; postrenal transplant; posaconazole therapy
Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl’s Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.
Deferasirox effectively controls liver iron concentration; however, little is known regarding its ability to remove stored cardiac iron. Deferiprone seems to have increased cardiac efficacy compared with traditional deferoxamine therapy. Therefore, the relative efficacy of deferasirox and deferiprone were compared in removing cardiac iron from iron-loaded gerbils.
Twenty-nine 8- to 10-week-old female gerbils underwent 10 weekly iron dextran injections of 200 mg/kg/week. Prechelation iron levels were assessed in 5 animals, and the remainder received deferasirox 100 mg/kg/D po QD (n = 8), deferiprone 375 mg/kg/D po divided TID (n = 8), or sham chelation (n = 8), 5 days/week for 12 weeks.
Deferasirox reduced cardiac iron content 20.5%. No changes occurred in cardiac weight, myocyte hypertrophy, fibrosis, or weight-to-dry weight ratio. Deferasirox treatment reduced liver iron content 51%. Deferiprone produced comparable reductions in cardiac iron content (18.6% reduction). Deferiprone-treated hearts had greater mass (16.5% increase) and increased myocyte hypertrophy. Deferiprone decreased liver iron content 24.9% but was associated with an increase in liver weight and water content.
Deferasirox and deferiprone were equally effective in removing stored cardiac iron in a gerbil animal model, but deferasirox removed more hepatic iron for a given cardiac iron burden.
In the absence of an iron chelating agent, patients with beta-thalassemia on regular
transfusions present complications of transfusion-related iron overload. Without iron
chelation therapy, heart disease is the major cause of death; however, hepatic and
endocrine complications also occur. Currently there are three iron chelating agents
available for continuous use in patients with thalassemia on regular transfusions
(desferrioxamine, deferiprone, and deferasirox) providing good results in reducing
cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the
Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA), presents a
review of the literature regarding iron overload assessment (by imaging and
laboratory exams) and the role of T2* magnetic resonance imaging (MRI) to control
iron overload and iron chelation therapy, with evidence-based recommendations for
each clinical situation. Based on this review, the authors propose an iron chelation
protocol for patients with thalassemia under regular transfusions.
Blood transfusion; Chelation therapy; Deferiprone; Deferasirox; Iron/metabolism; beta-Thalassemia; Iron overload; Iron chelating agents; Magnetic resonance imaging; Practice guidelines as topic; Protocols; Brazil
To date, there is a lack of long-term safety and efficacy data for iron chelation therapy in transfusion-dependent patients with sickle cell disease (SCD). To evaluate the long-term safety and efficacy of deferasirox (a once-daily oral iron chelator), patients with SCD completing a 1-year, Phase II, randomized, deferoxamine (DFO)-controlled study entered a 4-year extension, continuing to receive deferasirox, or switching from DFO to deferasirox. Average actual deferasirox dose was 19·4 ± 6·3 mg/kg per d. Of 185 patients who received at least one deferasirox dose, 33·5% completed the 5-year study. The most common reasons for discontinuation were withdrawal of consent (23·8%), lost to follow-up (9·2%) and adverse events (AEs) (7·6%). Investigator-assessed drug-related AEs were predominantly gastrointestinal [including nausea (14·6%), diarrhoea (10·8%)], mild-to-moderate and transient in nature. Creatinine clearance remained within the normal range throughout the study. Despite conservative initial dosing, serum ferritin levels in patients with ≥4 years deferasirox exposure significantly decreased by −591 μg/l (95% confidence intervals, −1411, −280 μg/l; P=0·027; n=67). Long-term deferasirox treatment for up to 5 years had a clinically acceptable safety profile, including maintenance of normal renal function, in patients with SCD. Iron burden was substantially reduced with appropriate dosing in patients treated for at least 4 years.
deferasirox; Exjade; oral iron chelator; sickle cell disease; iron overload
Deferasirox is a once-daily, oral iron chelator developed for treating transfusional iron overload. Preclinical studies indicated that the kidney was a potential target organ of toxicity. As patients with sickle cell disease often have abnormal baseline renal function, the primary objective of this randomised, open-label, phase II trial was to evaluate the safety and tolerability of deferasirox in comparison with deferoxamine in this population. Assessment of efficacy, as measured by change in liver iron concentration (LIC) using biosusceptometry, was a secondary objective. A total of 195 adult and paediatric patients received deferasirox (n = 132) or deferoxamine (n = 63). Adverse events most commonly associated with deferasirox were mild, including transient nausea, vomiting, diarrhoea, abdominal pain and skin rash. Abnormal laboratory studies with deferasirox were occasionally associated with mild non-progressive increases in serum creatinine and reversible elevations in liver function tests. Discontinuation rates from deferasirox (11·4%) and deferoxamine (11·1%) were similar. Over 1 year, similar dose-dependent LIC reductions were observed with deferasirox and deferoxamine. Once-daily oral deferasirox has acceptable tolerability and appears to have similar efficacy to deferoxamine in reducing iron burden in transfused patients with sickle cell disease.
deferasirox; ICL670; Exjade; sickle cell disease; iron overload
Many patients with bone marrow failure syndromes need frequent transfusions of red blood cells, and most of them eventually suffer from organ dysfunction induced by excessively accumulated iron. The only way to treat transfusion-induced iron overload is iron chelating therapy. However, most patients have not been treated effectively because daily/continuous administration of deferoxamine is difficult for outpatients. Recently, a novel oral iron chelator, deferasirox, has been developed, and introduction of the drug may help many patients benefit from iron chelation therapy. In this review, we will discuss the current status of iron overload in transfusion-dependent patients, and the development of Japanese guidelines for the treatment of iron overload in Japan, which were established by the National Research Group on Idiopathic Bone Marrow Failure Syndromes in Japan.
Bone marrow failure syndrome; Iron overload; Iron chelation; Guidelines
Transfusional iron overload in patients with chronic anemias can result in multiple organ failure. Experience in the management of iron overload in patients with myelodysplastic syndromes is limited, as many do not receive chelation therapy due to short-life expectancy and the difficulties associated with the administration of the current reference standard chelator, deferoxamine. There have, however, been some reports of reduced transfusion requirement associated with chelation therapy in patients with myelodysplastic syndromes and myelofibrosis. Here, we discuss a patient with primary myelofibrosis and related transfusion-dependent anemia who received chelation therapy with the once-daily oral iron chelator, deferasirox. In addition to the reduced iron levels, the patient demonstrated an unexpected reduction in blood transfusion requirement, ultimately resulting in long-lasting transfusion-free survival.
myelofibrosis; iron overload; chelation
Because of the rising incidence of failures in the treatment of oropharyngeal candidosis in the case of severely immunosuppressed patients (mostly human immunodeficiency virus [HIV]-infected patients), there is need for the development of new, more effective agents and/or compounds that support the activity of the common antifungal agents. Since lactoferrin is one of the nonspecific host defense factors present in saliva that exhibit antifungal activity, we studied the antifungal effects of human, bovine, and iron-depleted lactoferrin in combination with fluconazole, amphotericin B, and 5-fluorocytosine in vitro against clinical isolates of Candida species. Distinct antifungal activities of lactoferrin were observed against clinical isolates of Candida. The MICs generally were determined to be in the range of 0.5 to 100 mg · ml−1. Interestingly, in the combination experiments we observed pronounced cooperative activity against the growth of Candida by using lactoferrin and the three antifungals tested. Only in a limited concentration range was minor antagonism detected. The use of lactoferrin and fluconazole appeared to be the most successful combination. Significant reductions in the minimal effective concentrations of fluconazole were found when it was combined with a relatively low lactoferrin concentration (1 mg/ml). Such combinations still resulted in complete growth inhibition, while synergy of up to 50% against several Candida species was observed. It is concluded that the combined use of lactoferrin and antifungals against severe infections with Candida is an attractive therapeutic option. Since fluconazole-resistant Candida species have frequently been reported, especially in HIV-infected patients, the addition of lactoferrin to the existing fluconazole therapy could postpone the occurrence of species resistance against fluconazole. Clinical studies to further elucidate the potential utility of this combination therapy have been initiated.
The ability of Pseudomonas aeruginosa to form antibiotic-resistant biofilms is thought to account for the inability of current therapies to resolve bacterial infections in the lungs of patients with cystic fibrosis (CF). We recently described a system in which highly antibiotic-resistant P. aeruginosa biofilms grow on human CF airway epithelial cells, and using this system we showed that enhanced iron release from CF cells facilitates the development of such highly antibiotic-resistant biofilms. Given the positive role for iron in biofilm development, we investigated whether the FDA-approved iron chelators deferoxamine and deferasirox would enhance the ability of tobramycin, the primary antibiotic used to treat CF lung infections, to eliminate P. aeruginosa biofilms. The combination of tobramycin with deferoxamine or deferasirox reduced established biofilm biomass by approximately 90% and reduced viable bacteria by 7-log units. Neither tobramycin nor deferoxamine nor deferasirox alone had such a marked effect. The combination of tobramycin and FDA-approved iron chelators also prevented the formation of biofilms on CF airway cells. These data suggest that the combined use of tobramycin and FDA-approved iron chelators may be an effective therapy to treat patients with CF and other lung disease characterized by antibiotic-resistant P. aeruginosa biofilms.
antibiotic resistance; biofilms; deferoxamine; deferasirox; cystic fibrosis model