Cardiac effects of deferasirox in transfusion-dependent patients with myelodysplastic syndromes: TELESTO study.

Iron overload from repeated transfusions has a negative impact on cardiac function, and iron chelation therapy may help prevent cardiac dysfunction in transfusion-dependent patients with myelodysplastic syndromes (MDS). TELESTO (NCT00940602) was a prospective, placebo-controlled, randomised study to evaluate the iron chelator deferasirox in patients with low- or intermediate-1-risk MDS and iron overload. Echocardiographic parameters were collected at screening and during treatment. Patients receiving deferasirox experienced a significant decrease in the composite risk of hospitalisation for congestive heart failure (CHF) or worsening of cardiac function (HR = 0.23; 95% CI: 0.05, 0.99; nominal p = 0.0322) versus placebo. No significant differences between the arms were found in left ventricular ejection fraction, ventricular diameter and mass or pulmonary artery pressure. The absolute number of events was low, but the enrolled patients were younger than average for patients with MDS, with no serious cardiac comorbidities and a modest cardiovascular risk profile. These results support the effectiveness of deferasirox in preventing cardiac damage caused by iron overload in this patient population. Identification of patients developing CHF is challenging due to the lack of distinctive echocardiographic features. The treatment of iron overload may be important to prevent cardiac dysfunction in these patients, even those with moderate CHF risk.

Differential effects of iron chelators on iron burden and long-term morbidity and mortality outcomes in a large cohort of transfusion-dependent ß-thalassemia patients who remained on the same monotherapy over 10 years.

We conducted a retrospective cohort study on 663 transfusion-dependent ß-thalassemia patients receiving the same iron chelation monotherapy with deferoxamine, deferiprone, or deferasirox for up to 10 years (median age 31.8 years, 49.9 % females). Patients on all three iron chelators had a steady and significant decline in serum ferritin over the 10 years (median deferoxamine: -170.7 ng/mL, P = 0.049, deferiprone: -236.7 ng/mL, P = 0.001; deferasirox: -323.7 ng/mL, P < 0.001) yet had no significant change in liver iron concentration or cardiac T2*; while noting that patients generally had low hepatic and cardiac iron levels at study start. Median absolute, relative, and normalized changes were generally comparable between the three iron chelators. Patients receiving deferasirox had the highest morbidity and mortality-free survival probability among the three chelators, although the difference was only statistically significant when compared with deferoxamine (P = 0.037). On multivariate Cox regression analysis, there was no significant association between iron chelator type and the composite outcome of morbidity or mortality. In a real-world setting, there is comparable long-term iron chelation effectiveness between the three available iron chelators for patients with mild-to-moderate iron overload.

Diagnosing aceruloplasminemia: navigating through red herrings.

A 58-year-old female was found to have hyperferritinemia (Serum ferritin:1683 ng/mL) during work-up for mild normocytic anemia. Transferrin saturation(TSAT) was low-normal. Magnetic resonance imaging (MRI) abdomen showed evidence of hepatic iron deposition. Liver biopsy showed 4 + hepatic iron deposition without any evidence of steatosis or fibrosis. Quantitative liver iron was elevated at 348.3 µmol/g dry liver weight [Reference range(RR): 3-33 µmol/g dry liver weight]. She was presumptively diagnosed with tissue iron overload, cause uncertain. A diagnosis of ferroportin disease (FD) was considered, but the pattern of iron distribution in the liver, mainly within the hepatic parenchyma (rather than in the hepatic Kupffer cells seen in FD), and the presence of anemia (uncommon in FD) made this less likely. She was treated with intermittent phlebotomy for over a decade with poor tolerance due to worsening normocytic to microcytic anemia. A trial of deferasirox was done but it was discontinued after a month due to significant side effects. During the course of treatment, her ferritin level decreased. Over the past 1.5 years, she developed progressively worsening neurocognitive decline. MRI brain showed areas of susceptibility involving basal ganglia, midbrain and cerebellum raising suspicion for metabolic deposition disease. Neuroimaging findings led to testing for serum copper and ceruloplasmin levels which were both found to be severely low. Low serum copper, ceruloplasmin levels and neuroimaging findings led us to consider Wilson disease however prior liver biopsy showing elevated hepatic iron rather than hepatic copper excluded the diagnosis of Wilson disease. After shared decision making, ceruloplasmin gene analysis was not pursued due to patient's preference and prohibitive cost of testing. The diagnosis of aceruloplasminemia was ultimately made. The biochemical triad of hyperferritinemia, low-normal TSAT and microcytic anemia should raise the possibility of aceruloplasminemia. Since neurological manifestations are rare in most inherited iron overload syndromes, neurological symptoms in a patient with tissue iron overload should prompt consideration of aceruloplasminemia as a differential diagnosis.

The impact of chelation compliance in health outcome and health related quality of life in thalassaemia patients: a systematic review.

Understanding consequences of poor chelation compliance is crucial given the enormous burden of post-transfusional iron overload complications. We systematically reviewed iron-chelation therapy (ICT) compliance, and the relationship between compliance with health outcome and health-related quality of life (HRQoL) in thalassaemia patients. Several reviewers performed systematic search strategy of literature through PubMed, Scopus, and EBSCOhost. The preferred reporting items of systematic reviews and meta-analyses (PRISMA) guidelines were followed. Of 4917 studies, 20 publications were included. The ICT compliance rate ranges from 20.93 to 75.3%. It also varied per agent, ranging from 48.84 to 85.1% for desferioxamine, 87.2-92.2% for deferiprone and 90-100% for deferasirox. Majority of studies (N = 10/11, 90.91%) demonstrated significantly negative correlation between compliance and serum ferritin, while numerous studies revealed poor ICT compliance linked with increased risk of liver disease (N = 4/7, 57.14%) and cardiac disease (N = 6/8, 75%), endocrinologic morbidity (N = 4/5, 90%), and lower HRQoL (N = 4/6, 66.67%). Inadequate compliance to ICT therapy is common. Higher compliance is correlated with lower serum ferritin, lower risk of complications, and higher HRQoL. These findings should be interpreted with caution given the few numbers of evidence.

Potential anticancer effect of free and nanoformulated Deferasirox for breast cancer treatment: in-vitro and in-vivo evaluation.

BACKGROUND: Breast cancer (BC) stands as the second-leading cause of mortality among women worldwide. Many chemotherapeutic treatments for BC come with significant adverse effects. Additionally, BC is recognized as one of the most resistant forms of malignancy to treatment. Consequently, there exists a critical need for innovative therapeutic agents that are both highly effective and exhibit reduced toxicity and side effects for patients. Deferasirox (DFX), an iron-chelating drug approved by the FDA for oral use, emerges as a promising contender in the fight against BC proliferation. DFX, primarily administered orally, is utilized to address chronic iron excess resulting from blood transfusions, and it is the inaugural treatment for chronic iron overload syndrome. However, DFX encounters limitations due to its poor water solubility. AIM: This study aimed at incorporating DFX into lipid nanocapsules (DFX-LNCs) followed by investigating the anticancer effect of the DFX nanoform as compared to free DFX in-vitro and on an orthotopic BC mouse model in-vivo. METHODS: The DFX-LNCs was prepared and imaged using TEM and also characterized in terms of particle size (PS), zeta potential (ZP), and polydispersity index (PDI) using DLS. Moreover, drug release, cytotoxicity, and anticancer effect were assessed in-vitro, and in-vivo. RESULTS: The results revealed that DFX-LNCs are more cytotoxic than free DFX with IC50 of 4.417 µg/ml and 16.114 µg/ml, respectively, while the plain LNCs didn't show any cytotoxic effect on the 4T1 cell line (IC50 = 122.797 µg/ml). Besides, the apoptotic effect of DFX-LNCs was more pronounced than that of free DFX, as evidenced by Annexin V/PI staining, increased BAX expression, and decreased expression of BcL-2. Moreover, DFX-LNCs showed a superior antitumor effect in-vivo with potent antioxidant and anti-proliferative effects. CONCLUSION: The newly developed DFX nanoform demonstrated a high potential as a promising therapeutic agent for BC treatment.

Efficacy and Safety of a Dispersible Tablet of GPO-Deferasirox Monotherapy among Children with Transfusion-Dependent Thalassemia and Iron Overload.

The study aimed to determine efficacy and safety of generic deferasirox monotherapy. Deferasirox was administered in transfusion-induced iron overloaded thalassemia. Efficacy was defined as responders and nonresponders by ≤ 15 reduced serum ferritin from baseline. Adverse events were also monitored. Fifty-two patients with mainly Hb E/ß-thalassemia at the mean (SD) age of 8.7 (4.1) years, were enrolled. The mean (SD) daily transfusion iron load was 0.47 (0.1) mg/kg and maximum daily deferasirox was 35.0 (6.2) mg/kg. Altogether, 52, 40 and 18 patients completed the first, second and third years of study, respectively. The median baseline serum ferritin 2,383 ng/mL decreased to 1,478, 1,038 and 1,268 ng/mL at the end of first, second and third years, respectively, with overall response rate at 73.1% (38/52). Patients with baseline serum ferritin >2,500 ng/mL showed a change in serum ferritin higher than those ≤2,500 ng/mL starting from the 9th month of chelation. Adverse events were found in 5 of 52 patients (9.6%) including transaminitis (n = 2), one each of proteinuria, rash and proximal tubular dysfunction which resolved after transient stopping or decreasing the chelation dose. Generic deferasirox was effective and safe among pediatric patients with transfusion-induced iron overloaded thalassemia.

COMPARATIVE STUDY OF OXIDATIVE STRESS IN PATIENTS WITH Β -THALASSEMIA MAJOR ON DEFERASIROX VERSUS DEFEROXAMINE THERAPY.

Accumulation of iron in vital organs is increasingly challenging in clinical settings during the lifespan of thalassemia patients. Iron overload hurdle these organs to redox imbalances. Commonly used iron-chelating agents in (deferasirox and, deferoxamine) could have a positive antioxidant role. Therefore, the aim of this study was designed to compare the effects of deferasirox and, deferoxamine, iron-chelating agents in oxidative stress in patients with ß-thalassemic major. In this case series comparative study, 60 known cases of ß-thalassemic patients receiving chelating agents therapy were divided into two groups of thirty, group one consisted of 30 patients 16 male and14 female, who received oral agent deferasirox tablets at dose 20-40mg/kg. Group two consisted of 30 patients, 16 male and 14 female, on intravenous therapy with Deferoxamine at a dose of 20-50mg/kg, Another thirty healthy individuals matched with age and gender, were kept as a control group. Total antioxidant capacity (TAOC) and Malondialdehyde (MDA) were measured in all studied groups. The three groups were similar in terms of age, and gender, A statistically non-significant difference in age (p>0.05) existed between the control and patient groups (10.9±2.93; 11.2±4.1*;11.6±3.6*) respectively. The number of patients in to control group and male-to-female numbers were matched since the ratios were similar. A statistically non-significant difference in BMI (p>0.05) existed between the control and patient groups (17±2, 17.2±2, 18±2.4*) respectively. TAOC is lower in-patient groups, when compared with the control group (27.8 ± 10.7; 32.5 ± 10.2; and 79.5 ± 7 u/ml) respectively, while the MDA value is higher when compared with the control group (7.2±4.6 and, 6.6±4.42; and 0.57±0.26; nmol/ml) respectively. The TAOC in patients group on Deferoxamine, is higher, while MDA is lower than in patients on Defrasirox. The TAOC in patients was reduced and Oxidative stress was enhanced in patients with thalassemia. Deferoxamine is more effective in modulating redox status.

Evidence for the Metabolic Activation of Deferasirox In Vitro and In Vivo.

Deferasirox (DFS) is used for the treatment of iron accumulation caused by the need for long-term blood transfusions, such as thalassemia or other rare anemia. Liver injury due to exposure to DFS has been documented, and the toxic mechanisms of DFS are unknown. The present study aimed to investigate the reactive metabolites of DFS in vitro and in vivo to help us understand the mechanisms of DFS hepatotoxicity. Two hydroxylated metabolites (5-OH and 5'-OH) were identified during incubation of DFS-supplemented rat liver microsomes. Such microsomal incubations fortified with glutathione (GSH) or N-acetylcysteine (NAC) as capture agents offered two GSH conjugates and two NAC conjugates. These GSH conjugates and NAC conjugates were also detected in bile and urine of rats given DFS. CYP1A2 and CYP3A4 were found to dominate the metabolic activation of DFS. Administration of DFS induced decreased cell survival in cultured primary hepatocytes. Pretreatment with ketoconazole and 1-aminobenzotrizole made hepatocytes less susceptible to the cytotoxicity of DFS.

Patient preference for deferasirox film-coated versus dispersible tablet formulation: a sequential-design phase 2 study in patients with thalassemia.

Iron chelation therapy (ICT) is the mainstay of treatment in patients with thalassemia requiring blood transfusions. This phase 2 JUPITER study evaluated patient preference between film-coated tablet (FCT) and dispersible tablet (DT) in transfusion-dependent thalassemia (TDT) or non-TDT (NTDT) patients treated with both formulations in a sequential manner. The primary endpoint was patient-reported preference for FCT over DT, while secondary outcomes included patient reported outcomes (PROs) evaluated by overall preference, and by age, thalassemia transfusion status, and previous ICT status. Out of 183 patients screened, 140 and 136 patients completed the treatment periods 1 and 2 of the core study, respectively. At week 48, the majority of patients preferred FCT over DT (90.3 vs. 7.5%; difference of percentage: 0.83 [95% confidence interval (CI), 0.75-0.89; P < 0.0001]). FCT scored better on secondary PROs and showed less severe gastrointestinal symptoms than DT, except in the change of modified Satisfaction with Iron Chelation Therapy (mSICT) preference scores, which were similar for both the formulations. Patients with TDT had stable ferritin levels, while it showed a downward trend up to week 48 in patients with NTDT on deferasirox treatment. Overall, 89.9% of patients reported ≥ 1 adverse event (AE), of which 20.3% experienced ≥ 1 serious AE. The most common treatment-emergent AEs were proteinuria, pyrexia, urine protein/creatinine ratio increase, diarrhea, upper respiratory tract infections, transaminase increase, and pharyngitis. Overall, this study reinforced the observations from the previous study by showing a distinct patient preference for FCT over DT formulation and further supported the potential benefits of life-long compliance with ICT.

Iron chelation therapy.

Iron overload is a pathological condition resulting from a congenital impairment of its regulation, increased intestinal iron absorption secondary to bone marrow erythroid hyperplasia, or a chronic transfusional regimen. In normal conditions, intracellular and systemic mechanisms contribute to maintaining iron balance. When this complex homeostatic mechanism fails, an iron overload could be present. Detecting an iron overload is not easy. The gold standard remains the liver biopsy, even if it is invasive and dangerous. Identifying iron using noninvasive techniques allowed a better understanding of the rate of iron overload in different organs, with a low risk for the patient. Estimating serum ferritin (mg/L) is the easiest and, consequently, the most employed diagnostic tool for assessing body iron stores, even if it could be a not specific method. The most common hematological causes of iron overload are myelodysplastic syndromes, sickle cell disease, and thalassemia. In all of these conditions, three drugs have been approved for the treatment of iron overload: deferiprone, deferoxamine, and deferasirox. These chelators have been demonstrated to help lower tissue iron levels and prevent iron overload complications, improving event-free survival (EFS). Nowadays, the decision to start chelation and which chelator to choose remains the joint decision of the clinician and patient.

Nephrolithiasis in two patients on iron chelation therapy: A case report.

Drug-induced nephrolithiasis can arise from insoluble components within medications or crystallization of metabolites due to changes in metabolism and urinary pH. The connection between drugs utilized for iron chelation therapy (ICT) and nephrolithiasis is not well understood. In this report, we describe two pediatric patients diagnosed with nephrolithiasis while undergoing treatment with the chelating agents deferasirox, deferiprone, and deferoxamine for iron overload secondary to repeat blood transfusion.

Tuning the Solid- and Solution-State Fluorescence of the Iron-Chelator Deferasirox.

Deferasirox, an FDA-approved iron chelator, has gained increasing attention for use in anticancer and antimicrobial applications. Recent efforts by our group led to the identification of this core as an easy-to-visualize aggregation-induced emission platform, or AIEgen, that provides a therapeutic effect equivalent to deferasirox (J. Am. Chem. Soc. 2021, 143, 3, 1278-1283). However, the emission wavelength of the first-generation system overlapped with that of Syto9, a green emissive dye used to indicate live cells. Here, we report a library of deferasirox derivatives with various fluorescence emission profiles designed to overcome this limitation. We propose referring to systems that show promise as both therapeutic and optical imaging agents as "illuminoceuticals". The color differences between the derivatives were observable to the unaided eye (solid- and solution-state) and were in accord with the Commission Internationale de L'Eclairage (CIE) chromaticity diagram 1913. Each fluorescent derivative successfully imaged the respective spherical and rod shapes of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. They also displayed iron-dependent antibiotic activity. Three derivatives, ExNMe2 (3), ExTrisT (11), and ExDCM (13), display emission features that are sufficiently distinct so as to permit the multiplex (triplex) imaging of both MRSA and P. aeruginosa via stimulated emission depletion microscopy. The present deferasirox derivatives allowed for the construction of a multi-fluorophore sensor array. This array enabled the successful discrimination between Gram-positive/Gram-negative and drug-sensitive/drug-resistant bacteria. Antibiotic sensitivity and drug-resistant mutants from clinically isolated strains could also be identified and differentiated.

Deferasirox in the management of iron overload in patients with myelofibrosis treated with ruxolitinib: The multicentre retrospective RUX-IOL study.

Deferasirox (DFX) is used for the management of iron overload (IOL) in many haematological malignancies including myelofibrosis (MF). The 'RUX-IOL' study retrospectively collected 69 MF patients treated with ruxolitinib (RUX) and DFX for IOL to assess: safety, efficacy in term of iron chelation response (ICR) and erythroid response (ER), and impact on overall survival of the combination therapy. The RUX-DFX therapy was administered for a median time of 12.4 months (interquartile range 3.1-71.2). During treatment, 36 (52.2%) and 34 (49.3%) patients required RUX and DFX dose reductions, while eight (11.6%) and nine (13.1%) patients discontinued due to RUX- or DFX-related adverse events; no unexpected toxicity was reported. ICR and ER were achieved by 33 (47.8%) and 32 patients (46.4%) respectively. Thirteen (18.9%) patients became transfusion-independent. Median time to ICR and ER was 6.2 and 2 months respectively. Patients achieving an ER were more likely to obtain an ICR also (p = 0.04). In multivariable analysis, the absence of leukocytosis at baseline (p = 0.02) and achievement of an ICR at any time (p = 0.02) predicted improved survival. In many MF patients, the RUX-DFX combination provided ICR and ER responses that correlated with improved outcome in the absence of unexpected toxicities. This strategy deserves further clinical investigation.

Risk factors for endocrine complications in transfusion-dependent thalassemia patients on chelation therapy with deferasirox: a risk assessment study from a multi-center nation-wide cohort.

Transfusion-dependent patients typically develop iron-induced cardiomyopathy, liver disease, and endocrine complications. We aimed to estimate the incidence of endocrine disorders in transfusiondependent thalassemia (TDT) patients during long-term iron-chelation therapy with deferasirox (DFX). We developed a multi-center follow-up study of 426 TDT patients treated with once-daily DFX for a median duration of 8 years, up to 18.5 years. At baseline, 118, 121, and 187 patients had 0, 1, or ≥2 endocrine diseases respectively. 104 additional endocrine diseases were developed during the follow-up. The overall risk of developing a new endocrine complication within 5 years was 9.7% (95% Confidence Interval [CI]: 6.3-13.1). Multiple Cox regression analysis identified three key predictors: age showed a positive log-linear effect (adjusted hazard ratio [HR] for 50% increase 1.2, 95% CI: 1.1-1.3, P=0.005), the serum concentration of thyrotropin showed a positive linear effect (adjusted HR for 1 mIU/L increase 1.3, 95% CI: 1.1-1.4, P<0.001) regardless the kind of disease incident, while the number of previous endocrine diseases showed a negative linear effect: the higher the number of diseases at baseline the lower the chance of developing further diseasess (adjusted HR for unit increase 0.5, 95% CI: 0.4-0.7, P<0.001). Age and thyrotropin had similar effect sizes across the categories of baseline diseases. The administration of levothyroxine as a covariate did not change the estimates. Although in DFX-treated TDT patients the risk of developing an endocrine complication is generally lower than the previously reported risk, there is considerable risk variation and the burden of these complications remains high. We developed a simple risk score chart enabling clinicians to estimate their patients' risk. Future research will look at increasing the amount of variation explained from our model and testing further clinical and laboratory predictors, including the assessment of direct endocrine magnetic resonance imaging.

Modern management of iron overload in thalassemia major patients guided by MRI techniques: real-world data from a long-term cohort study.

Monitoring liver and cardiac iron stores by magnetic resonance imaging (MRI) enables identifying patients at risk of organ-specific morbidity and better tailoring of iron chelation therapy in thalassemia. Nevertheless, serum ferritin (SF) remains the only tool for monitoring iron status in most resource-poor regions. In this study, we assessed the impact of using MRI techniques to guide iron chelation therapy on iron overload outcomes in a cohort of 99 patients with thalassemia major (TM, mean age at baselines 20.7 ± 6.9 years) followed from 2006 to 2019. We also assessed the ability of SF trends to predict changes in consecutive liver iron concentration (LIC) and cardiac T2* (cT2*) measurements. The most commonly used chelator was deferasirox at baseline (65%) and final (72%) assessments. Overall, patients with safe LIC values (< 7 mg/g dw) increased from 57 to 77%, and safe cT2* values (> 20 ms) increased from 72 to 86%. We obtained the most significant improvement in patients with severe and moderate liver (p = 0.006 and p < 0.001) and cardiac (p < 0.0013 and p < 0.0001) iron overload at baseline. SF trends were in the same direction in 64% of changes in LIC, but only 42% of changes were proportional. Most of the changes in SF (64%) and LIC (61%) could not predict changes in cT2*. Moreover, downward trends in SF and LIC were associated with worsening cardiac iron in 29% and 23.5% of consecutive cT2* measurements. Liver and cardiac MRI-driven oral iron chelation improved the iron status of subjects with TM and demonstrated the importance of using validated MRI techniques in critical clinical decisions.

Deferasirox shows inhibition activity against cervical cancer in vitro and in vivo.

OBJECTIVE: Iron depletion may be a novel therapeutic strategy for cancer. This study aimed to assess the inhibition effects of deferasirox (DFX), an oral iron chelator, on cervical cancer. METHODS: In this study, we performed immunohistochemical analysis, enzyme-linked immunoassay, cell viability and invasive ability assay, cell cycle and apoptosis analysis, protein expression investigation, molecular mechanism investigation, and in vivo murine xenograft model to evaluate the impact of DFX on cervical cancer. RESULTS: The cervical cancer cell lines viability decreased and cell apoptosis was induced after DFX incubation. Additionally, DFX promoted cell cycle arrest by regulating the expression of cell cycle regulators cyclin D1, cyclin E and proliferating cell nuclear antigen (PCNA) in cervical cancer cell lines. DFX also decreased cell invasion by upregulating the expression of NDRG1 and downregulating c-Myc. The activation of Akt and the MEK/ERK signaling pathway was inhibited by DFX. DFX also significantly suppressed xenograft tumor growth, decreased the levels of ferritin in serum and tumor tissue, reduced iron deposits and reactive oxygen species (ROS) levels in xenografts of DFX-treated group compared with the control group, with no serious side effects. CONCLUSION: Present study demonstrated the inhibitory effect of DFX against cervical cancer, and provided a potential therapeutic agent for cervical cancer.

Effects of dual chelation therapy with deferasirox and deferoxamine in patients with beta thalassaemia major.

BACKGROUND AND OBJECTIVES: Patients with thalassaemia experience complications related to iron overload. In Australia currently, the two main options for iron chelation are deferasirox and deferoxamine. Optimal iron chelation using monotherapy can be limited due to toxicity or tolerability. Dual chelation therapy (DCT) may provide more aggressive iron chelation. MATERIAL AND METHODS: A retrospective, observational study was performed on a state-wide referral centre for patients receiving red cell transfusions for haemoglobinopathies (Monash Health, Australia). All patients prescribed DCT were identified using a local pharmacy dispensing database and were included in the study. Pre-DCT initiation and post-DCT completion were correlated with serum ferritin, cardiac iron loading (based on MRI T2* measurements) and liver iron content (LIC) using Wilcoxon signed-rank test. RESULTS: A total of 18 patients (12 adults, 6 children) were identified as receiving DCT. All patients received a combination of deferasirox and deferoxamine. The median duration of therapy was 23 months (range 2-73). Median serum ferritin reduced by 42% (p = 0.004) and there was a 76% reduction in LIC (p = 0.062). No significant changes were seen in cardiac iron loading. CONCLUSION: DCT over a prolonged period is effective at reducing serum ferritin and may contribute to improvement in liver iron loading.

Characterisation of individual ferritin response in patients receiving chelation therapy.

AIMS: To develop a drug-disease model describing iron overload and its effect on ferritin response in patients affected by transfusion-dependent haemoglobinopathies and investigate the contribution of interindividual differences in demographic and clinical factors on chelation therapy with deferiprone or deferasirox. METHODS: Individual and mean serum ferritin data were retrieved from 13 published studies in patients affected by haemoglobinopathies receiving deferiprone or deferasirox. A nonlinear mixed effects modelling approach was used to characterise iron homeostasis and serum ferritin production taking into account annual blood consumption, baseline demographic and clinical characteristics. The effect of chelation therapy was parameterised as an increase in the iron elimination rate. Internal and external validation procedures were used to assess model performance across different study populations. RESULTS: An indirect response model was identified, including baseline ferritin concentrations and annual blood consumption as covariates. The effect of chelation on iron elimination rate was characterised by a linear function, with different slopes for each drug (0.0109 [90% CI: 0.0079-0.0131] vs. 0.0013 [90% CI: 0.0008-0.0018] L/mg mo). In addition to drug-specific differences in the magnitude of the ferritin response, simulation scenarios indicate that ferritin elimination rates depend on ferritin concentrations at baseline. CONCLUSION: Modelling of serum ferritin following chronic blood transfusion enabled the evaluation of drug-induced changes in iron elimination rate and ferritin production. The use of a semi-mechanistic parameterisation allowed us to disentangle disease-specific factors from drug-specific properties. Despite comparable chelation mechanisms, deferiprone appears to have a significantly larger effect on the iron elimination rate than deferasirox.

Efficacy and Safety of Iron Chelation Therapy After Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Thalassemia Patients: A Retrospective Observational Study.

BACKGROUND: Studies on the increased body iron load in patients with thalassemia major have thoroughly demonstrated the problems caused by iron overload. In patients who undergo hematopoietic stem cell transplantation (HSCT) as curative therapy, iron overload continues long after transplantation. There are few pediatric studies on chelation therapy in the posttransplant period. In this study, we present the outcomes of our patients who received posttransplant oral chelation therapy. PATIENTS AND METHODS: This retrospective observational study evaluated the outcomes of pediatric patients with thalassemia major who used oral chelation therapy after allogeneic HSCT at the Akdeniz University Pediatric Bone Marrow Unit between January 2008 and October 2019. RESULTS: Deferasirox therapy was initiated in 58 pediatric patients who underwent HSCT for thalassemia. Pretreatment mean serum ferritin was 2166±1038 ng/mL. Treatment was initiated at a mean of 12±6.7 months after transplantation and continued for a mean of 15.7±11.5 months. At treatment discontinuation, the mean serum ferritin was 693±405 ng/mL and the mean reduction was -1472.75±1121.09 ng/mL (P<0.001 vs. posttreatment). Serum ferritin was below 500 ng/mL in 52% of the patients at treatment discontinuation. Manageable side effects such as nausea, vomiting, liver enzyme elevation, and proteinuria were observed in 17% of the patients, while one patient developed ototoxicity. CONCLUSIONS: Deferasirox therapy effectively reduces iron overload in the posttransplant period. Studies evaluating the effects of early treatment on the graft may help to establish guidelines for posttransplant chelation therapy. Clear guidelines are needed regarding when to initiate and discontinue treatment.

Asbestos-induced mesothelial injury and carcinogenesis: Involvement of iron and reactive oxygen species.

Asbestos fibers have been used as an industrial and construction material worldwide due to their high durability and low production cost. Commercial usage of asbestos is currently prohibited in Japan; however, the risk of asbestos-induced malignant mesothelioma (MM) remains. According to epidemiological data, the onset of MM is estimated to occur after a latent period of 30-40 years from initial exposure to asbestos fibers; thus, the continuous increase in MM is a concern. To explore the molecular mechanisms of MM using animal models, iron saccharate with iron chelator-induced sarcomatoid mesothelioma (SM) revealed hallmarks of homozygous deletion of Cdkn2a/2b by aCGH and microRNA-199/214 by expression microarray. Oral treatment of iron chelation by deferasirox decreased the rate of high-grade SM. Moreover, phlebotomy delayed MM development in crocidolite-induced MM in rats. In Divalent metal transporter 1 (Dmt1) transgenic mice, MM development was delayed because of low reactive oxygen species (ROS) production. These results indicate the importance of iron and ROS in mesothelial carcinogenesis. The aims of this review focus on the pathogenesis of elongated mineral particles (EMPs), including asbestos fibers and multiwalled carbon nanotubes (MWCNTs) that share similar rod-like shapes in addition to the molecular mechanisms of MM development.