Efficacy and safety of deferasirox in myelodysplastic syndromes

Skin complications during iron chelation therapy for beta-thalassemia: overview and treatment approach

Thalassemia is an inherited genetic disorder of hemoglobin that affects a large population worldwide, and it is estimated that between 50,000 and 60,000 infants with thalassemia are born each year. The most common treatment for thalassemia is blood transfusion, which leads to iron overload. This in itself is a serious clinical condition, and is commonly managed with iron chelation therapy. However, iron chelators can cause various skin complications, including hyperpigmentation, skin rash, itching, and photosensitivity. These skin side effects can impact patients' quality of life. Therefore, this article provides a comprehensive overview of skin complications caused by iron chelators, along with a proposed comprehensive approach to their management in patients with beta-thalassemia. Key strategies include patient education, regular skin assessment, sun protection measures, symptomatic relief with topical corticosteroids and antihistamines, and consideration of treatment modification if severe complications occur. Collaboration between hematologists and dermatologists, along with psychological support and regular follow-up, is an essential component of this multidisciplinary approach. By implementing these strategies, healthcare providers can optimize skin care for patients with beta-thalassemia treated with iron chelators and improve their quality of life.

Therapy-resistant nature of cancer stem cells in view of iron metabolism

Due to increased resistance to standard chemo/radiotherapies and relapse, highly tumorigenic cancer stem cells (CSCs) have been proposed as a promising target for the development of effective cancer treatments. In order to develop innovative cancer therapies that target CSCs, much attention has focused on the iron metabolism of CSCs, which has been considered to contribute to self-renewal of CSCs. Here, we review recent advances in iron metabolism and conventional iron metabolism-targeted cancer therapies, as well as therapy resistance of CSCs and potential treatment options to overcome them, which provide important insights into therapeutic strategies against intractable cancers. Potential treatment options targeting iron homeostasis, including small-molecule inhibitors, nanotechnology platforms, ferroptosis, and 5-ALA-PDT, might be a focus of future research for the development of innovative cancer therapies that tackle CSCs.

Iron Metabolism in Cancer

Demanded as an essential trace element that supports cell growth and basic functions, iron can be harmful and cancerogenic though. By exchanging between its different oxidized forms, iron overload induces free radical formation, lipid peroxidation, DNA, and protein damages, leading to carcinogenesis or ferroptosis. Iron also plays profound roles in modulating tumor microenvironment and metastasis, maintaining genomic stability and controlling epigenetics. in order to meet the high requirement of iron, neoplastic cells have remodeled iron metabolism pathways, including acquisition, storage, and efflux, which makes manipulating iron homeostasis a considerable approach for cancer therapy. Several iron chelators and iron oxide nanoparticles (IONPs) has recently been developed for cancer intervention and presented considerable effects. This review summarizes some latest findings about iron metabolism function and regulation mechanism in cancer and the application of iron chelators and IONPs in cancer diagnosis and therapy.

Clinical consequences of iron overload in patients with myelodysplastic syndromes: the case for iron chelation therapy

INTRODUCTION

Patients with myelodysplastic syndromes (MDS) are at increased risk of iron overload due to ineffective erythropoiesis and chronic transfusion therapy. The clinical consequences of iron overload include cardiac and/or hepatic failure, endocrinopathies, and infection risk. Areas covered: Iron chelation therapy (ICT) can help remove excess iron and ultimately reduce the clinical consequences of iron overload. The authors reviewed recent (last five years) English-language articles from PubMed on the topic of iron overload-related complications and the use of ICT (primarily deferasirox) to improve outcomes in patients with MDS. Expert commentary: While a benefit of ICT has been more firmly established in other transfusion-dependent conditions, such as thalassemia, its role in reducing iron overload in MDS remains controversial due to the lack of prospective controlled data demonstrating a survival benefit. Orally administered chelation agents (e.g. deferasirox) are now available, and observational and/or retrospective data support a survival benefit of using ICT in MDS. The placebo-controlled TELESTO trial (NCT00940602) is currently examining the use of deferasirox in MDS patients with iron overload, and is evaluating specifically whether use of ICT to alleviate iron overload can also reduce iron overload-related complications in MDS and improve survival.

Comparison of the effects of deferasirox, deferoxamine, and combination of deferasirox and deferoxamine on an aplastic anemia mouse model complicated with iron overload

Background and aim

Iron overload is commonly observed during the course of aplastic anemia (AA), which is believed to aggravate hematopoiesis, cause multiple organ dysfunction, lead to disease progression, and impair quality of life. Deferasirox (DFX) and deferoxamine (DFO) are among the most common iron chelation agents available in the clinical setting. The aim of this study was to investigate if the combination therapy with DFX and DFO is superior in hematopoietic recovery and iron chelation.

Methods

Briefly, we developed a composite mouse model with AA and iron overload that was consequently treated with DFX, DFO, or with a combination of both agents. The changes in peripheral hemogram, marrow apoptosis, and its related protein expressions were compared during the process of iron chelation, while the iron depositions in liver and bone marrow and its regulator were also detected.

Results

The obtained results showed that compared to DFX, DFO has a better effect in protecting the bone marrow from apoptosis-induced failure. The combination of DFO and DFX accelerated the chelation of iron, while their efficiency on further hemogram improvement appeared limited.

Conclusion

To sum up, our data suggest that single treatment with DFO may be a better choice for improving the hematopoiesis during the gradual chelation treatment irrespective of the convenience of oral DFX, while the combination treatment should be considered for urgent reduction of the iron burden.

Deferasirox-induced urticarial vasculitis in a patient with myelodysplastic syndrome

Deferasirox is an iron chelator agent used in the treatment of diseases with iron overload, such as thalassemia and myelodysplastic syndrome. Although the majority of adverse reactions of deferasirox involve gastrointestinal symptoms and increase in serum creatinine and transaminases, skin rashes, such as maculopapular and urticarial eruptions, have also been reported. This study reports a case of myelodysplastic syndrome with urticarial vasculitis due to deferasirox therapy. Drug eruption was been confirmed by means of a challenge test, together with histopathological and clinical findings. To the best of our knowledge, we report the first case of deferasirox-induced urticarial vasculitis. Physicians should be aware of the possibility of urticarial vasculitis on deferasirox therapy and the fact that the discontinuation of the drug generally results in improvement.

Iron-chelating therapy with deferasirox in transfusion-dependent, higher risk myelodysplastic syndromes: a retrospective, multicentre study

Iron chelation is controversial in higher risk myelodysplastic syndromes (HR-MDS), outside the allogeneic transplant setting. We conducted a retrospective, multicentre study in 51 patients with transfusion-dependent, intermediate-to-very high risk MDS, according to the revised international prognostic scoring system, treated with the oral iron chelating agent deferasirox (DFX). Thirty-six patients (71%) received azacitidine concomitantly. DFX was given at a median dose of 1000 mg/day (range 375-2500 mg) for a median of 11 months (range 0·4-75). Eight patients (16%) showed grade 2-3 toxicities (renal or gastrointestinal), 4 of whom (8%) required drug interruption. Median ferritin levels decreased from 1709 μg/l at baseline to 1100 μg/l after 12 months of treatment (P = 0·02). Seventeen patients showed abnormal transaminase levels at baseline, which improved or normalized under DFX treatment in eight cases. One patient showed a remarkable haematological improvement. At a median follow up of 35·3 months, median overall survival was 37·5 months. The results of this first survey of DFX in HR-MDS are comparable, in terms of safety and efficacy, with those observed in lower-risk MDS. Though larger, prospective studies are required to demonstrate real clinical benefits, our data suggest that DFX is feasible and might be considered in a selected cohort of HR-MDS patients.

Treatment of Myelofibrosis: Old and New Strategies

Myelofibrosis (MF) is a BCR-ABL1-negative myeloproliferative neoplasm that is mainly characterised by reactive bone marrow fibrosis, extramedullary haematopoiesis, anaemia, hepatosplenomegaly, constitutional symptoms, leukaemic progression, and shortened survival. As such, this malignancy is still orphan of curative treatments; indeed, the only treatment that has a clearly demonstrated impact on disease progression is allogeneic haematopoietic stem cell transplantation, but only a minority of patients are eligible for such intensive therapy. However, more recently, the discovery of JAK2 mutations has also led to the development of small-molecule JAK1/2 inhibitors, the first of which, ruxolitinib, has been approved for the treatment of MF in the United States and Europe. In this article, we report on old and new therapeutic strategies that proved effective in early preclinical and clinical trials, and subsequently in the daily clinical practice, for patients with MF, particularly concerning the topics of anaemia, splenomegaly, iron overload, and allogeneic stem cell transplantation.

Anti-leukemic effects of the V-ATPase inhibitor Archazolid A

Prognosis for patients suffering from T-ALL is still very poor and new strategies for T-ALL treatment are urgently needed. Our study shows potent anti-leukemic effects of the myxobacterial V-ATPase inhibitor Archazolid A. Archazolid A reduced growth and potently induced death of leukemic cell lines and human leukemic samples. By inhibiting lysosomal acidification, Archazolid A blocked activation of the Notch pathway, however, this was not the mechanism of V-ATPase inhibition relevant for cell death induction. In fact, V-ATPase inhibition by Archazolid A decreased the anti-apoptotic protein survivin. As underlying mode of action, this work is in line with recent studies from our group demonstrating that Archazolid A induced S-phase cell cycle arrest by interfering with the iron metabolism in leukemic cells. Our study provides evidence for V-ATPase inhibition as a potential new therapeutic option for T-ALL.

CONIFER - Non-Interventional Study to Evaluate Therapy Monitoring During Deferasirox Treatment of Iron Toxicity in Myelodysplastic Syndrome Patients with Transfusional Iron Overload

BACKGROUND

The non-interventional study CONIFER was designed to assess the safety and clinical practicability of deferasirox for the treatment of transfusional iron overload in myelodysplastic syndrome (MDS) patients.

METHODS

Patients included in the study were diagnosed with MDS and received at least 1 treatment with deferasirox. The observation period covered the time from the initial visit until the last follow-up.

RESULTS

The data of 99 patients with MDS scored mainly as International Prognostic Scoring System (IPSS) low and intermediate 1 were evaluated. The mean age of the participants was 75 years and 58% of the patients were male. Iron overload was assessed by serum ferritin level (mean baseline serum ferritin 2,080 ± 1,244 µg/l). Patients were treated for a mean duration of 16 months (mean daily dose at baseline 11.8 ± 7.0 mg/kg). Stratification of serum ferritin levels by deferasirox dose showed a reduction at the higher but no reduction at the lower dose (< 15 mg/kg vs. ≥ 15 mg/kg and < 20 mg/kg vs. ≥ 20 mg/kg). The majority of patients (81%) were affected by at least 1 adverse event, with decreased renal creatinine clearance being the most frequent.

CONCLUSION

Higher doses (≥ 15 mg/kg) of deferasirox effectively and safely reduced serum ferritin levels in MDS patients with transfusional iron overload.

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells

BACKGROUND/AIMS

The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies.

METHODS

We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib.

RESULTS

Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-κB (NF-κB) and β-catenin.

CONCLUSIONS

We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-κB and β-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML.

Association between renal iron accumulation and renal interstitial fibrosis in a rat model of chronic kidney disease

Iron accumulation is associated with the pathophysiology of chronic kidney disease (CKD). Renal fibrosis is a final common feature that contributes to the progression of CKD; however, little is known about the association between renal iron accumulation and renal interstitial fibrosis in CKD. Here we investigate the effects of iron chelation on renal interstitial fibrosis in a rat model of CKD. CKD was induced by 5/6 nephrectomy in Sprague-Dawley rats. At 8 weeks after operation, 5/6 nephrectomized rats were administered an oral iron chelator, deferasirox (DFX), in chow for 8 weeks. Other CKD rats were given a normal diet. Sham-operative rats given a normal diet served as a control. CKD rats exhibited hypertension, glomerulosclerosis and renal interstitial fibrosis. Iron chelation with DFX did not change hypertension and glomerulosclerosis; however, renal interstitial fibrosis was attenuated in CKD rats. Consistent with these findings, renal gene expression of collagen type III and transforming growth factor-β was increased in CKD rats compared with the controls, while iron chelation suppressed these increments. In addition, a decrease in vimentin along an increase in E-cadherin in renal gene expression was observed in CKD rats with iron chelation. CKD rats also showed increased CD68-positive cells in the kidney, whereas its increase was attenuated by iron deprivation. Similarly, increased renal gene expression of CD68, tumor necrosis factor-α and monocyte chemoattractant protein-1 was suppressed in CKD rats with iron chelation. Renal iron accumulation seems to be associated with renal interstitial fibrosis in a rat model of CKD.

Dual effect of oxidative stress on leukemia cancer induction and treatment

Oxidative stress (OS) has been characterized by an imbalance between the production of reactive oxygen species (ROS) and a biological system's ability to repair oxidative damage or to neutralize the reactive intermediates including peroxides and free radicals. High ROS production has been associated with significant decrease in antioxidant defense mechanisms leading to protein, lipid and DNA damage and subsequent disruption of cellular functions. In humans, OS has been reported to play a role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, Lou Gehrig's disease, multiple sclerosis and Parkinson's disease, as well as atherosclerosis, autism, cancer, heart failure, and myocardial infarction. Although OS has been linked to the etiology and development of chronic diseases, many chemotherapeutic drugs have been shown to exert their biologic activity through induction of OS in affected cells. This review highlights the controversial role of OS in the development and progression of leukemia cancer and the therapeutic application of increased OS and antioxidant approaches to the treatment of leukemia patients.

Deferasirox for managing iron overload in people with myelodysplastic syndrome

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Iron chelation therapy with deferasirox in the management of iron overload in primary myelofibrosis

Deferasirox (DSX) is the principal option currently available for iron-chelation-therapy (ICT), principally in the management of myelodysplastic syndromes (MDS), while in primary myelofibrosis (PMF) the expertise is limited. We analyzed our experience in 10 PMF with transfusion-dependent anemia, treated with DSX from September 2010 to December 2013. The median dose tolerated of DSX was 750 mg/day (10 mg/kg/day), with 3 transient interruption of treatment for drug-related adverse events (AEs) and 3 definitive discontinuation for grade 3/4 AEs. According to IWG 2006 criteria, erythroid responses with DSX were observed in 4/10 patients (40%), 2 of them (20%) obtaining transfusion independence. Absolute changes in median serum ferritin levels (Delta ferritin) were greater in hematologic responder (HR) compared with non-responder (NR) patients, already at 6 months of ICT respect to baseline. Our preliminary data open new insights regarding the benefit of ICT not only in MDS, but also in PMF with the possibility to obtain an erythroid response, overall in 40 % of patients. HR patients receiving DSX seem to have a better survival and a lower incidence of leukemic transformation (PMF-BP). Delta ferritin evaluation at 6 months could represent a significant predictor for a different survival and PMF-BP. However, the tolerability of the drug seems to be lower compared to MDS, both in terms of lower median tolerated dose and for higher frequency of discontinuation for AEs. The biological mechanism of action of DSX in chronic myeloproliferative setting through an independent NF-κB inhibition could be involved, but further investigations are required.

The anti-apoptotic gene Anamorsin is essential for both autonomous and extrinsic regulation of murine fetal liver hematopoiesis

Anamorsin (AM) is an antiapoptotic molecule that confers factor-independent survival on hematopoietic cells. AM-deficient (AM(-/-)) mice are embryonic lethal because of a defect in definitive hematopoiesis; however, the significance of AM in embryonic hematopoiesis remains unknown. This study characterized the hematopoietic defects in AM(-/-) fetal livers. The AM(-/-) fetal liver displayed significantly reduced numbers of c-Kit(+)Sca-1(+)Lin(-) (KSL) cells. An in vitro colony-forming unit assay showed that fetal liver cells isolated from AM(-/-) embryos gave rise to fewer colonies in all cell types. The reconstitution activity in AM(-/-) hematopoietic stem cells (HSCs) was markedly reduced in all lineages. Furthermore, the limiting dilution assay revealed that the number of fetal liver HSCs was reduced because of AM deficiency. Retrovirus-mediated AM expression rescued the defective hematopoietic colony-forming activities of AM(-/-) KSL cells. We also investigated the effects of AM deficiency on fetal liver stromal cells, which support hematopoiesis. Interestingly, primary stromal cell cultures from wild type fetal liver supported the growth of AM(-/-) KSL cells, but stromal cultures from AM(-/-) fetal liver provided little support of wild type KSL cell growth. These results demonstrated that AM was essential for both autonomous and extrinsic regulation of fetal liver hematopoiesis. This study provided new insight into the molecular regulation of hematopoiesis.

Oxidative stress in sickle cell disease: an overview of erythrocyte redox metabolism and current antioxidant therapeutic strategies

Erythrocytes have an environment of continuous pro-oxidant generation due to the presence of hemoglobin (Hb), which represents an additional and quantitatively significant source of superoxide (O2(-)) generation in biological systems. To counteract oxidative stress, erythrocytes have a self-sustaining antioxidant defense system. Thus, red blood cells uniquely function to protect Hb via a selective barrier allowing gaseous and other ligand transport as well as providing antioxidant protection not only to themselves but also to other tissues and organs in the body. Sickle hemoglobin molecules suffer repeated polymerization/depolymerization generating greater amounts of reactive oxygen species, which can lead to a cyclic cascade characterized by blood cell adhesion, hemolysis, vaso-occlusion, and ischemia-reperfusion injury. In other words, sickle cell disease is intimately linked to a pathophysiologic condition of multiple sources of pro-oxidant processes with consequent chronic and systemic oxidative stress. For this reason, newer therapeutic agents that can target oxidative stress may constitute a valuable means for preventing or delaying the development of organ complications.

Iron chelation in the treatment of cancer: a new role for deferasirox?

Iron plays a crucial role in a number of metabolic pathways including oxygen transport, DNA synthesis, and ATP generation. Although insufficient systemic iron can result in physical impairment, excess iron has also been implicated in a number of diseases including ischemic heart disease, diabetes, and cancer. Iron chelators are agents which bind iron and facilitate its excretion. Experimental iron chelators have demonstrated potent anti-neoplastic properties in a number of cancers in vitro. These agents have yet to be translated into clinical practice, however, largely due to the significant side effects encountered in pre-clinical models. A number of licensed chelators, however, are currently in clinical use for the treatment of iron overload associated with certain non-neoplastic diseases. Deferasirox is one such agent and the drug has shown significant anti-tumor effects in a number of in vitro and in vivo studies. Deferasirox is orally administered and has demonstrated a good side effect profile in clinical practice to date. It represents an attractive agent to take forward into clinical trials of iron chelators as anti-cancer agents.