Does iron chelation therapy improve survival in regularly transfused lower risk MDS patients? A multicenter study by the GFM

Treatment characteristics and outcomes in lower-risk, non-del(5q) myelodysplastic syndromes: findings from a medical record review in the USA, Canada and Europe

Aim: To assess treatment patterns and outcomes in patients with non-del(5q) lower-risk myelodysplastic syndromes. Methods: Patient medical records were reviewed in the USA, Canada (CAN), UK and the EU. Results: Analysis included 119 patients in the USA/CAN (median age, 61.5 years) and 245 patients in the UK/EU (median age, 67.3 years). Most patients received erythropoiesis-stimulating agents (ESAs) as first-line (1L) therapy (USA/CAN: 89.0%; UK/EU: 90.2%). A substantial proportion of 1L erythropoiesis-stimulating agent-treated patients were transfusion dependent before 1L (USA/CAN: 37.1%; UK/EU: 51.2%); a small percentage of these patients achieved transfusion independence during 1L therapy (USA/CAN: 2.8%; UK/EU: 14.4%). Conclusion: These findings highlight an unmet need for more effective treatments among patients with non-del(5q) lower-risk myelodysplastic syndromes.

The Role of Hepcidin in Myelodysplastic Syndromes (MDS): A Systematic Review of Observational Studies

Iron overload emerges as a serious complication in myelodysplastic syndromes (MDS), particularly associated with frequent transfusions during the course of the disease. The discovery and description of hepcidin's mechanisms of action have contributed to a deeper understanding of iron metabolism. The existing literature reports a potential role of hepcidin in MDS, yet these data are fragmented and presented in an unstructured, somewhat chaotic manner. Hence, to address the existing data, we performed a systematic review of observational studies examining hepcidin levels in MDS. An extensive review of three bibliographic databases (Pubmed, Web of Science, and Scopus) enabled us to identify 12 observational studies. These studies focused primarily on adult patients with low-risk MDS who underwent transfusions and chelation therapy. An in-depth analysis of these manuscripts led to four main conclusions: (1) although high serum hepcidin levels are associated with MDS, most studies generally have not found a significant difference in these levels between patients and healthy individuals; (2) serum hepcidin levels are specific to MDS type; (3) serum hepcidin levels in MDS are strongly associated with transfusions and the genetic status of patients; and (4) high-risk MDS is associated with high serum hepcidin levels. While we have furnished a comprehensive summary of the significance of hepcidin in MDS, there are still gaps that future research should address. This pertains primarily to the capacity of hepcidin in predicting adverse outcomes for MDS patients and evaluating the efficacy of chelation therapy or the need for transfusion.

[Transfusions and iron chelation in myelodysplastic syndromes]

Iron overload (IO) is probably as toxic in elderly patients with low-risk myelodysplastic syndromes (MDS) as in young thalassemic patients. This impact is more difficult to demonstrate because of associated comorbidities. Cardiovascular disease increases vulnerability to the toxic effects of IO. In recent years, registry studies have shown a survival benefit of Iron Chelation Therapy (ICT) in these patients. These findings are now corroborated by an improvement in event-free survival in a single randomized study: the Telesto study. The EFS curves separate after two years of follow-up. This indicates inertia in the occurrence of complications. The benefits of ICT are also very slowly being revealed. It is possible to offer ICT to patients with transfusion-dependent MDS with a life expectancy of at least two years. In Telesto, patients had a serum ferritin (F) level of at least 1000ng/mL, recommendations using this F threshold as a trigger for chelation seem to be reinforced. It remains an open question whether chelation should be started earlier for effective suppression of IO-related oxidative stress. ICTs could be used in transfusion-dependent MDS patients with life expectancy greater than two years. including possibly higher risk patients responding to hypomethylating agents.

Lower-risk myelodysplastic syndromes: Current treatment options for anemia

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematological disorders. Treatment options are classified and defined by prognostic risk based on the International Prognostic Scoring System (IPSS) and, more recently, the revised IPSS (IPSS-R). The treatment goal for lower-risk MDS is to correct cytopenias or their consequences, with the goal of maintaining or improving quality of life. Erythropoiesis-stimulating agents (ESAs) play an important role in treating anemia. Individuals with MDS who have a 5q deletion are particularly sensitive to treatment with lenalidomide; however, this comprises the minority of patients with MDS. Luspatercept was recently approved in the United States and the European Union for the treatment of ESA-refractory MDS with ring sideroblasts. Research into new treatment options, especially after ESA failure, is needed. In this review, we will focus on the current therapeutic options for MDS-related anemia.

Iron overload disorders

Iron overload disorders represent a variety of conditions that lead to increased total body iron stores and resultant end-organ damage. An elevated ferritin and transferrin-iron saturation can be commonly encountered in the evaluation of elevated liver enzymes. Confirmatory homeostatic iron regulator (HFE) genetic testing for C282Y and H63D, mutations most encountered in hereditary hemochromatosis, should be pursued in evaluation of hyperferritinemia. Magnetic resonance imaging with quantitative assessment of iron content or liver biopsy (especially if liver disease is a cause of iron overload) should be used as appropriate. A secondary cause for iron overload should be considered if HFE genetic testing is negative for the C282Y homozygous or C282Y/H63D compound heterozygous mutations. Differential diagnosis of secondary iron overload includes hematologic disorders, iatrogenic causes, or chronic liver diseases. More common hematologic disorders include thalassemia syndromes, myelodysplastic syndrome, myelofibrosis, sideroblastic anemias, sickle cell disease, or pyruvate kinase deficiency. If iron overload has been excluded, evaluation for causes of hyperferritinemia should be pursued. Causes of hyperferritinemia include chronic liver disease, malignancy, infections, kidney failure, and rheumatic conditions, such as adult-onset Still's disease or hemophagocytic lymphohistiocytosis. In this review, we describe the diagnostic testing of patients with suspected hereditary hemochromatosis, the evaluation of patients with elevated serum ferritin levels, and signs of secondary overload and treatment options for those with secondary iron overload.

Prognostic Factors and Clinical Considerations for Iron Chelation Therapy in Myelodysplastic Syndrome Patients

Iron chelation therapy (ICT) is an important tool in the treatment of transfusion-dependent lower-risk myelodysplastic syndrome (MDS) patients. ICT is effective in decreasing iron overload and consequently in limiting its detrimental effects on several organs, such as the heart, liver, and endocrine glands. Besides this effect, ICT also proved to be effective in improving peripheral cytopenia in a significant number of MDS patients, thus further increasing the clinical interest of this therapeutic tool. In the first part of the review, we will analyze the toxic effect of iron overload and its mechanism. Subsequently, we will revise the clinical role of ICT in various subsets of MDS patients (low, intermediate, and high risk MDS, patients who are candidates for allogeneic stem cell transplantation).

Impact of iron overload by transfusion on survival and leukemia transformation of myelodysplastic syndromes in a single center of China

INTRODUCTION

Myelodysplastic syndromes (MDS) are a heterogeneous group of diseases which are prone to progress into acute myeloid leukemia (AML). Iron overload (IOL) caused by transfusion occurred in most MDS patients. But how IOL influences MDS progression has not been clarified yet.

METHODS

Herein, we collected clinical data from 143 MDS patients to investigate the impacts of IOL on patients survival and AML transformation.

RESULTS

We found that median survival time, 3-year survival rate, leukemia-free survival (LFS) time were significantly shorter in patients with IOL than those with non-iron overload (NIOL) (P = 0.040; P = 0.044; P = 0.037). Besides, IOL was more likely to be found in higher-risk subgroups (assessed by IPSS and WPSS) of MDS patients which also promoted 2-year AML transformation. Furthermore, the serum ferritin (SF) was significantly correlated with the overall survival (OS) of MDS patients (r = -0.311, P < 0.05). The concentrations of both intracellular iron and reactive oxygen species (ROS) in CD34⁺ cells of bone marrow were higher in the IOL group than the NIOL group, respectively (P = 0.0426; P = 0.0185). Moreover, ROS level was closely correlated with the percentage of bone marrow blasts (r = 0.7200, P = 0.0370). Collectively, IOL threatened the survival of MDS patients and promoted AML transformation.

CONCLUSION

Elevated intracellular iron and ROS in CD34⁺ cells of bone marrow could accelerate the abnormal proliferation of blasts.

From Biology to Clinical Practice: Iron Chelation Therapy With Deferasirox

Iron chelation therapy (ICT) has become a mainstay in heavily transfused hematological patients, with the aim to reduce iron overload (IOL) and prevent organ damage. This therapeutic approach is already widely used in thalassemic patients and in low-risk Myelodysplastic Syndrome (MDS) patients. More recently, ICT has been proposed for high-risk MDS, especially when an allogeneic bone marrow transplantation has been planned. Furthermore, other hematological and hereditary disorders, characterized by considerable transfusion support to manage anemia, could benefit from this therapy. Meanwhile, data accumulated on how iron toxicity could exacerbate anemia and other clinical comorbidities due to oxidative stress radical oxygen species (ROS) mediated by free iron species. Taking all into consideration, together with the availability of approved oral iron chelators, we envision a larger use of ICT in the near future. The aim of this review is to better identify those non-thalassemic patients who can benefit from ICT and give practical tips for management of this therapeutic strategy.

Myelodysplastic Syndromes: A New Decade

Myelodysplastic syndromes (MDS) are a group of heterogeneous clonal hematopoietic stem cell disorders. The 2020 Surveillance, Epidemiology, and End Results data demonstrates the incidence rate of MDS increases with age especially in those greater than 70 years of age. Risk stratification that impact prognosis, survival, and rate of acute myeloid leukemia (AML) transformation in MDS is largely dependent on revised International Prognostic Scoring System along with molecular genetic testing as a supplement. Low risk MDS typically have a more indolent disease course in which treatment is only initiated to ameliorate symptoms of cytopenias. In many, anemia is the most common cytopenia requiring treatment and erythroid stimulating agents, are considered first line. In contrast, high risk MDS tend to behave more aggressively for which treatment should be initiated rapidly with Hypomethylating Agents (HMA) being in the frontline. In those with high risk MDS and eligible, evaluation for allogeneic stem cell transplant should be considered as this is the only potential curative option for MDS. With the use of molecular genetic testing, a personalized approach to therapy in MDS has ensued. As the treatment landscape in MDS continues to flourish with novel targeted agents, we ambitiously seek to improve survival rates especially among the relapsed/refractory and transplant ineligible.

Iron overload-induced oxidative stress in myelodysplastic syndromes and its cellular sequelae

The myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders. MDS patients often require red blood cell transfusions, resulting in iron overload (IOL). IOL increases production of reactive oxygen species (ROS), oxygen free radicals. We review and illustrate how IOL-induced ROS influence cellular activities relevant to MDS pathophysiology. ROS damage lipids, nucleic acids in mitochondrial and nuclear DNA, structural proteins, transcription factors and enzymes. Cellular consequences include decreased metabolism and tissue and organ dysfunction. In hematopoietic stem cells (HSC), consequences of ROS include decreased glycolysis, shifting the cell from anaerobic to aerobic metabolism and causing HSC to exit the quiescent state, leading to HSC exhaustion or senescence. ROS oxidizes DNA bases, resulting in accumulation of mutations. Membrane oxidation alters fluidity and permeability. In summary, evidence indicates that IOL-induced ROS alters cellular signaling pathways resulting in toxicity to organs and hematopoietic cells, in keeping with adverse clinical outcomes in MDS.

The Clinical Significance of Iron Overload and Iron Metabolism in Myelodysplastic Syndrome and Acute Myeloid Leukemia

Myelodysplasticsyndrome (MDS) and acute myeloid leukemia (AML) are clonal hematopoietic stem cell diseases leading to an insufficient formation of functional blood cells. Disease-immanent factors as insufficient erythropoiesis and treatment-related factors as recurrent treatment with red blood cell transfusions frequently lead to systemic iron overload in MDS and AML patients. In addition, alterations of function and expression of proteins associated with iron metabolism are increasingly recognized to be pathogenetic factors and potential vulnerabilities of these diseases. Iron is known to be involved in multiple intracellular and extracellular processes. It is essential for cell metabolism as well as for cell proliferation and closely linked to the formation of reactive oxygen species. Therefore, iron can influence the course of clonal myeloid disorders, the leukemic environment and the occurrence as well as the defense of infections. Imbalances of iron homeostasis may induce cell death of normal but also of malignant cells. New potential treatment strategies utilizing the importance of the iron homeostasis include iron chelation, modulation of proteins involved in iron metabolism, induction of leukemic cell death via ferroptosis and exploitation of iron proteins for the delivery of antileukemic drugs. Here, we provide an overview of some of the latest findings about the function, the prognostic impact and potential treatment strategies of iron in patients with MDS and AML.

Treatment options for lower-risk myelodysplastic syndromes. Where are we now?

Myelodysplastic syndromes (MDS) are a spectrum of clonal stem-cell disorders characterized clinically by bone-marrow failure. Resultant cytopenias are responsible for significant mortality and decreased quality of life in patients with MDS. In patients with low-risk MDS (LR-MDS), anemia is the most common cytopenia and erythropoiesis-stimulating agents (ESA) are usually used as first-line therapy. Those patients who become refractory to ESA have a poor survival. Available treatment options such as lenalidomide, hypomethylating agents, and immunosuppressive therapy can provide some hematologic response among selected subsets of patients, however durable responses are limited, and these agents can carry significant adverse effects. Chronic transfusions help to alleviate symptoms of anemia but still carry risks associated with transfusion and iron overload. Luspatercept, recently approved for those LR-MDS with ring sideroblasts refractory to ESA, was found to have an improvement in transfusion independence with a well-tolerated safety profile. While anemia is the most common cytopenia, thrombocytopenia and neutropenia management is challenging and the co-occurrence of these cytopenias with anemia may dictate the choice of therapy. In this article, we review LR-MDS and discuss the optimal use of current treatment options and explore new therapeutic options on the horizon.

Protein Carbonylation and Lipid Peroxidation in Hematological Malignancies

Among the different mechanisms involved in oxidative stress, protein carbonylation and lipid peroxidation are both important modifications associated with the pathogenesis of several diseases, including cancer. Hematopoietic cells are particularly vulnerable to oxidative damage, as the excessive production of reactive oxygen species and associated lipid peroxidation suppress self-renewal and induce DNA damage and genomic instability, which can trigger malignancy. A richer understanding of the clinical effects of oxidative stress might improve the prognosis of these diseases and inform therapeutic strategies. The most common protein carbonylation and lipid peroxidation compounds, including hydroxynonenal, malondialdehyde, and advanced oxidation protein products, have been investigated for their potential effect on hematopoietic cells in several studies. In this review, we focus on the most important protein carbonylation and lipid peroxidation biomarkers in hematological malignancies, their role in disease development, and potential treatment implications.

Deferasirox-Dependent Iron Chelation Enhances Mitochondrial Dysfunction and Restores p53 Signaling by Stabilization of p53 Family Members in Leukemic Cells

Iron is crucial to satisfy several mitochondrial functions including energy metabolism and oxidative phosphorylation. Patients affected by Myelodysplastic Syndromes (MDS) and acute myeloid leukemia (AML) are frequently characterized by iron overload (IOL), due to continuous red blood cell (RBC) transfusions. This event impacts the overall survival (OS) and it is associated with increased mortality in lower-risk MDS patients. Accordingly, the oral iron chelator Deferasirox (DFX) has been reported to improve the OS and delay leukemic transformation. However, the molecular players and the biological mechanisms laying behind remain currently mostly undefined. The aim of this study has been to investigate the potential anti-leukemic effect of DFX, by functionally and molecularly analyzing its effects in three different leukemia cell lines, harboring or not p53 mutations, and in human primary cells derived from 15 MDS/AML patients. Our findings indicated that DFX can lead to apoptosis, impairment of cell growth only in a context of IOL, and can induce a significant alteration of mitochondria network, with a sharp reduction in mitochondrial activity. Moreover, through a remarkable reduction of Murine Double Minute 2 (MDM2), known to regulate the stability of p53 and p73 proteins, we observed an enhancement of p53 transcriptional activity after DFX. Interestingly, this iron depletion-triggered signaling is enabled by p73, in the absence of p53, or in the presence of a p53 mutant form. In conclusion, we propose a mechanism by which the increased p53 family transcriptional activity and protein stability could explain the potential benefits of iron chelation therapy in terms of improving OS and delaying leukemic transformation.

Myelodysplastic syndromes: a review of therapeutic progress over the past 10 years

INTRODUCTION

Myelodysplastic syndromes (MDS) represent a range of bone marrow disorders, with patients affected by cytopenias and risk of progression to AML. There are limited therapeutic options available for patients, including hypomethylating agents (azacitidine/decitabine), growth factor support, lenalidomide, and allogeneic stem cell transplant.

AREAS COVERED

This review provides an overview of the progress made over the past decade for emerging therapies for lower- and higher-risk MDS (MDS-HR). We also cover advances in prognostication, supportive care, and use of allogeneic SCT in MDS.

EXPERT OPINION

While there have been no FDA-approved therapies for MDS in the past decade, we anticipate the approval of luspatercept based on results from the MEDALIST trial for patients with lower-risk MDS (MDS-LR) and ringed sideroblasts who have failed or are ineligible for erythropoiesis stimulating agents (ESAs). With growing knowledge of the biologic and molecular mechanisms underlying MDS, it is anticipated that new therapies will be approved in the coming years.

Controversies on the Consequences of Iron Overload and Chelation in MDS

Many patients with MDS are prone to develop systemic and tissue iron overload in part as a consequence of disease-immanent ineffective erythropoiesis. However, chronic red blood cell transfusions, which are part of the supportive care regimen to correct anemia, are the major source of iron overload in MDS. Increased systemic iron levels eventually lead to the saturation of the physiological systemic iron carrier transferrin and the occurrence of non-transferrin-bound iron (NTBI) together with its reactive fraction, the labile plasma iron (LPI). NTBI/LPI-mediated toxicity and tissue iron overload may exert multiple detrimental effects that contribute to the pathogenesis, complications and eventually evolution of MDS. Until recently, the evidence supporting the use of iron chelation in MDS was based on anecdotal reports, uncontrolled clinical trials or prospective registries. Despite not fully conclusive, these and more recent studies, including the TELESTO trial, unravel an overall adverse action of iron overload and therapeutic benefit of chelation, ranging from improved hematological outcome, reduced transfusion dependence and superior survival of iron-loaded MDS patients. The still limited and somehow controversial experimental and clinical data available from preclinical studies and randomized trials highlight the need for further investigation to fully elucidate the mechanisms underlying the pathological impact of iron overload-mediated toxicity as well as the effect of classic and novel iron restriction approaches in MDS. This review aims at providing an overview of the current clinical and translational debated landscape about the consequences of iron overload and chelation in the setting of MDS.

Iron Chelation in Transfusion-Dependent Patients With Low- to Intermediate-1-Risk Myelodysplastic Syndromes: A Randomized Trial

BACKGROUND

Iron chelation therapy (ICT) in patients with lower-risk myelodysplastic syndromes (MDS) has not been evaluated in randomized studies.

OBJECTIVE

To evaluate event-free survival (EFS) and safety of ICT in iron-overloaded patients with low- or intermediate-1-risk MDS.

DESIGN

Multicenter, randomized, double-blind, placebo-controlled trial (TELESTO). (ClinicalTrials.gov: NCT00940602).

SETTING

60 centers in 16 countries.

PARTICIPANTS

225 patients with serum ferritin levels greater than 2247 pmol/L; prior receipt of 15 to 75 packed red blood cell units; and no severe cardiac, liver, or renal abnormalities.

INTERVENTION

Deferasirox dispersible tablets (10 to 40 mg/kg per day) (n = 149) or matching placebo (n = 76).

MEASUREMENTS

The primary end point was EFS, defined as time from date of randomization to first documented nonfatal event (related to cardiac or liver dysfunction and transformation to acute myeloid leukemia) or death, whichever occurred first.

RESULTS

Median time on treatment was 1.6 years (interquartile range [IQR], 0.5 to 3.1 years) in the deferasirox group and 1.0 year (IQR, 0.6 to 2.0 years) in the placebo group. Median EFS was prolonged by approximately 1 year with deferasirox versus placebo (3.9 years [95% CI, 3.2 to 4.3 years] vs. 3.0 years [CI, 2.2 to 3.7 years], respectively; hazard ratio, 0.64 [CI, 0.42 to 0.96]). Adverse events occurred in 97.3% of deferasirox recipients and 90.8% of placebo recipients. Exposure-adjusted incidence rates of adverse events (≥15 events per 100 patient treatment-years) in deferasirox versus placebo recipients, respectively, were 24.7 versus 23.9 for diarrhea, 21.8 versus 18.7 for pyrexia, 16.7 versus 22.7 for upper respiratory tract infection, and 15.9 versus 0.9 for increased serum creatinine concentration.

LIMITATIONS

The protocol was amended from a phase 3 to a phase 2 study, with a reduced target sample size from 630 to 210 participants. There was differential follow-up between treatment groups.

CONCLUSION

The findings support ICT in iron-overloaded patients with low- to intermediate-1-risk MDS, with longer EFS compared with placebo and a clinically manageable safety profile. Therefore, ICT may be considered in these patients.

PRIMARY FUNDING SOURCE

Novartis Pharma AG.

Efficacy and safety of iron chelator for transfusion-dependent patients with myelodysplastic syndrome: a meta-analysis

To systematically evaluate the efficacy and safety of iron chelators for transfusion-dependent patients with MDS. Thirteen cohort studies with 12,990 patients diagnosed with MDS were included in this study. According to m eta-analysis results transfusion-dependent MDS patients with secondary iron overload had a longer (HR = 0.52, 95%CI = 0.43-0.62, P < 0.001). Further subgroup analysis revealed a longer LFS (HR = 0.84, 95%CI = 0.76-0.93, P = 0.001) in MDS patients receiving iron chelators than in MDS patients not receiving iron chelators (HR = 0.52, 95%CI = 0.43-0.62, P < 0.001) and in patients with lower-risk MDS (HR = 0.50, 95%CI = 0.43-0.59, P < 0.001). Subgroup analysis of DFX showed that compared with patients not treated with iron chelators, the group receiving DFX monotherapy had significantly increased OS (HR = 0.43, 95%CI = 0.27-0.69, P < 0.001). In terms of tolerance, meta-analysis of binary variables in CAEs indicated that the occurrence of CAEs was significantly reduced by ICT (RR = 0.64, 95%CI = 0.57-0.71, P < 0.001).

Evolving therapies for lower-risk myelodysplastic syndromes

The development in the therapeutic landscape of myelodysplastic syndromes (MDS) has substantially lagged behind other hematologic malignancies with no new drug approvals for MDS for 13 years since the approval of decitabine in the United States in 2006. While therapeutic concepts for MDS patients continue to be primarily defined by clinical-pathologic risk stratification tools such as the International Prognostic Scoring System (IPSS) and its revised version IPSS-R, our understanding of the genetic landscape and the molecular pathogenesis of MDS has greatly evolved over the last decade. It is expected that the therapeutic approach to MDS patients will become increasingly individualized based on prognostic and predictive genetic features and other biomarkers. Herein, we review the current treatment of lower-risk MDS patients and discuss promising agents in advanced clinical testing for the treatment of symptomatic anemia in lower-risk MDS patients such as luspatercept and imetelstat. Lastly, we review the clinical development of new agents and the implications of the wider availability of mutational analysis for the management of individual MDS patients.

Iron chelation therapy for myelodysplastic syndrome: a systematic review and meta-analysis

Iron overload remains a concern in myelodysplastic syndrome (MDS) patients especially those requiring recurrent blood transfusions. Whether iron chelating therapy (ICT) is beneficial to the long-term survival of myelodysplastic syndrome is still a controversial issue. Therefore, we conducted a systematic review and meta-analysis to clarify the relationship between ICT and long-term survival in patients with MDS. A total of 14 studies involving 7242 participants were identified; the outcomes revealed that for patients with MDS, ICT resulted in a lower risk of mortality compared to those with no ICT (HR 0.57; 95% CI 0.44-0.70; P < 0.001); what is more, ICT led to a lower risk of leukemia transformation (HR 0.70; 95% CI 0.52-0.93; P = 0.016). Results of subgroup analyses based on adequate ICT or any ICT, low/int-1 IPSS or unclassified IPSS and study types indicated that the ICT had a beneficial role in all these groups of patients.

Protein Carbonylation in Patients with Myelodysplastic Syndrome: An Opportunity for Deferasirox Therapy

Control of oxidative stress in the bone marrow (BM) is key for maintaining the interplay between self-renewal, proliferation, and differentiation of hematopoietic cells. Breakdown of this regulation can lead to diseases characterized by BM failure such as the myelodysplastic syndromes (MDS). To better understand the role of oxidative stress in MDS development, we compared protein carbonylation as an indicator of oxidative stress in the BM of patients with MDS and control subjects, and also patients with MDS under treatment with the iron chelator deferasirox (DFX). As expected, differences in the pattern of protein carbonylation were observed in BM samples between MDS patients and controls, with an increase in protein carbonylation in the former. Strikingly, patients under DFX treatment had lower levels of protein carbonylation in BM with respect to untreated patients. Proteomic analysis identified four proteins with high carbonylation levels in MDS BM cells. Finally, as oxidative stress-related signaling pathways can modulate the cell cycle through p53, we analyzed the expression of the p53 target gene p21 in BM cells, finding that it was significantly upregulated in patients with MDS and was significantly downregulated after DFX treatment. Overall, our results suggest that the fine-tuning of oxidative stress levels in the BM of patients with MDS might control malignant progression.

The impact of iron chelation therapy on patients with lower/intermediate IPSS MDS and the prognostic role of elevated serum ferritin in patients with MDS and AML: A meta-analysis

Serum ferritin (SF) has been identified as a potential prognostic factor for patients undergoing stem cell transplantation, but the prognostic value of SF in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) patients and the impact of iron chelation therapy (ICT) on MDS patients are controversial. The present meta-analysis aimed to better elucidate these relationships.Three electronic databases were searched systematically to identify reports on the prognostic role of SF in MDS and AML patients, and those investigating the impact of ICT on prognosis of MDS patients. The hazard ratios (HRs) and its 95% confidence interval (95%CI) were extracted from the identified studies using Cox proportional hazard regression model for overall survival (OS) and progression of MDS to AML.Twenty reports including 1066 AML patients and 4054 MDS patients were included in present study. The overall pooled HRs for OS of AML and MDS patients with elevated SF prior to transplantation was 1.73 (1.40-2.14), subgroup analyses stratified by the cut-off value of SF ≥1400/1000 ng/mL showed that the pooled HRs were 1.45 (0.98-2.15) and 1.65 (1.30-2.10), respectively. The pooled HRs for ICT in MDS patients was 0.30 (0.23-0.40). For ICT, the pooled HRs for the progression of MDS to AML was 0.84 (0.61-1.61).SF has a negative impact on the OS of AML and MDS patients when it is higher than 1000 ng/mL. ICT can improve the OS of MDS patients with iron overload but it is not associated with the progression of MDS to AML.

How we manage adults with myelodysplastic syndrome

The prognosis in Myelodysplastic syndromes (MDS), although recently refined by molecular studies, remains largely based on conventional prognostic scores [International Prognostic Scoring System (IPSS), revised IPSS], classifying patients into "lower risk" MDS (LR-MDS) and "higher risk" MDS (HR-MDS). In LR-MDS, treatment mainly aims at improving cytopenias, principally anaemia, while in HR-MDS it aims at delaying disease progression and prolonging survival. In LR-MDS without deletion 5q, anaemia is generally treated first by erythropoietic stimulating factors, while second line treatments are currently not approved [lenalidomide, hypomethylating agents (HMA), luspatercept] or rarely indicated (antithymocyte globulin). Lenalidomide has major efficacy in LR-MDS with deletion 5q. Allogeneic stem cell transplantation (allo-SCT) is sometimes considered in LR-MDS, and iron chelation can be considered when multiple red blood cell transfusions are required. Allo-SCT is the only potentially curative treatment for HR-MDS; however, it is rarely applicable. It is generally preceded by intensive chemotherapy (IC) or HMA in patients with excess of marrow blasts (especially if >10%). In other patients, HMA can improve survival. The role of new drugs, including venetoclax or, in case of specific mutations, IDH1 or IDH2 inhibitors, is investigated. IC is mainly indicated as a bridge to allo-SCT, in the absence of unfavourable karyotype.

Impact of treatment with iron chelation therapy in patients with lower-risk myelodysplastic syndromes participating in the European MDS registry

Iron overload due to red blood cell (RBC) transfusions is associated with morbidity and mortality in lower-risk myelodysplastic syndrome (MDS) patients. Many studies have suggested improved survival after iron chelation therapy (ICT), but valid data are limited. The aim of this study was to assess the effect of ICT on overall survival and hematologic improvement in lower-risk MDS patients in the European MDS registry. We compared chelated patients with a contemporary, non-chelated control group within the European MDS registry, that met the eligibility criteria for starting iron chelation. A Cox proportional hazards model was used to assess overall survival (OS), treating receipt of chelation as a time-varying variable. Additionally, chelated and non-chelated patients were compared using a propensity-score matched model. Of 2,200 patients, 224 received iron chelation. The hazard ratio and 95% confidence interval for OS for chelated patients, adjusted for age, sex, comorbidity, performance status, cumulative RBC transfusions, Revised-International Prognostic Scoring System (IPSS-R), and presence of ringed sideroblasts was 0.50 (0.34-0.74). The propensity-score analysis, matched for age, sex, country, RBC transfusion intensity, ferritin level, comorbidity, performance status, and IPSS-R, and, in addition, corrected for cumulative RBC transfusions and presence of ringed sideroblasts, demonstrated a significantly improved OS for chelated patients with a hazard ratio of 0.42 (0.27-0.63) compared to non-chelated patients. Up to 39% of chelated patients reached an erythroid response. In conclusion, our results suggest that iron chelation may improve OS and hematopoiesis in transfused lower-risk MDS patients. This trial was registered at clinicaltrials.gov identifier: 00600860.

Delayed time from RBC transfusion dependence to first cardiac event in lower IPSS risk MDS patients receiving iron chelation therapy

Transfused MDS patients are at risk for iron overload (IOL). IOL may exacerbate congestive heart failure (CHF), coronary artery disease (CAD) and arrythmias (ARR). We retrospectively examined cardiac events (CE) in red blood cell (RBC) transfusion dependent (TD) lower IPSS risk MDS patients. Patients were censored at death or MDS progression. 151 MDS patients were lower IPSS risk and RBC TD. Median number of cardiac risk factors (RF) per patient was 1 (1-4). CE following RBC TD occurred in 48 (32%) and were: CHF, n = 20; CAD, n = 15; ARR, n = 11. In univariate analysis factors significant for time to (TT) CE were: age at 1st RBC transfusion; number of RBCU transfused while lower IPSS risk; received iron chelation therapy (ICT); MDS treatment received; and number of cardiac RF/patient (p ≤ 0.02). Receiving ICT remained significant for TTCE in multivariate analysis (p = 0.03). Median TTCE in patients not receiving and receiving ICT was 7.0 (0.1-65.0) and 20.0 (0.1-148.6) months, respectively (p = 0.02). For lower IPSS risk RBC transfusion dependent MDS patients, time to first cardiac event following RBC TD was significantly longer in patients receiving ICT. These results suggest ICT may delay cardiac events in transfused patients. The results should be confirmed in larger numbers in prospective analyses.

[Management of myelodysplastic syndromes in 2019: An update]

Myelodysplastic syndromes are a heterogeneous group of clonal myeloid disorders characterized by peripheral cytopenias and an increased risk of progression to acute myeloid leukemia. Inflammatory, auto-immune or syndromic symptoms can make the diagnosis difficult. Diagnosis is currently based on bone marrow cytology but cytogenetics and molecular features are currently overpassing their initial prognostic function (allowing early diagnosis and prediction of therapeutic response). The prognostic classification is based on the Revised International Prognostic Scoring System, which also provides guidance for therapeutic management. The treatment of low-risk myelodysplastic syndromes is based on the correction of cytopenias (erythropoiesis stimulating agents, transfusions, lenalidomide, etc.), whereas in high-risk group, the goal is the control of the leukemic clone (hypomethylating agents, allograft of hematopoietic stem cell transplantation). Other molecules are used to manage complications of cytopenias or transfusion (anti-infectious prophylaxis and treatments, martial chelation). New molecules are being studied with some interesting results (luspatercept, venetoclax). This article aims to provide an update on the knowledge that an internist should know for the practical management of myelodysplastic syndromes in 2019.

The effect of vitamin D pathway genes and deferasirox pharmacogenetics on liver iron in thalassaemia major patients

Monitoring and treating iron overload is crucial in transfusion-dependent thalassaemia patients. Liver stiffness measurement by transient elastography and T2* magnetic resonance imaging represent non-invasive ways to evaluate the adequacy of the iron chelation treatment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity, and in deferasirox metabolism on liver iron burden parameters. One-hundred and five beta-thalassaemia patients, treated with deferasirox, have been enrolled. Drug plasma C_trough and AUC were measured by a HPLC-UV method. Allelic discrimination was performed by real-time PCR. Age, UGT1A1-364 CT/TT and CYP27B1 -1260 GT/TT positively predicted liver stiffness values. Deferasirox dose and serum ferritin negatively predicted T2* data, whereas age and CYP2D6 1457 GG genotype positively influenced these values. The discoveries of this research may be useful for personalized medicine and the proposed method could be applied in patients with hereditary hemochromatosis and myelodysplastic syndromes.

Systematic review and meta-analysis of the effect of iron chelation therapy on overall survival and disease progression in patients with lower-risk myelodysplastic syndromes

The impact of iron chelation therapy (ICT) on overall survival (OS) and progression to acute myeloid leukemia (AML) in patients with iron overload and International Prognostic Scoring System low- or intermediate-risk myelodysplastic syndromes (MDS) is not well understood. We conducted a systematic review and meta-analysis of published studies of ICT in patients with MDS to better elucidate these relationships. We searched PubMed, EMBASE, Cochrane databases, and the World Health Organization Clinical Trial Registry for studies reporting the impact of ICT on OS in patients with low- or intermediate-risk MDS. Studies were examined for demographics, effect measures, and potential bias risk. Fixed and random-effects models were used to calculate adjusted OS and adjusted hazards ratio (aHR) estimates, respectively, among the different studies. Nine observational studies (four prospective and five retrospective) were identified. For patients with MDS, ICT was associated with an overall lower risk of mortality compared with no ICT (aHR 0.42; 95% confidence interval (CI) 0.28-0.62; P < 0.01); however, there was significant heterogeneity across the studies. In studies reporting progression to AML, ICT was not associated with decreased risk of progression (odds ratio 0.68; 95% CI 0.31-1.43; P < 0.030). This systematic review and meta-analysis of nine nonrandomized trials demonstrated significant reduction in risk of mortality in patients with iron overload and low- or intermediate-risk MDS treated with ICT; however, a causal relationship cannot be established. Randomized, controlled trials are needed to more definitively evaluate the relationship between ICT and survival in patients with iron overload and low- or intermediate-risk MDS.

Deferasirox selectively induces cell death in the clinically relevant population of leukemic CD34+CD38- cells through iron chelation, induction of ROS, and inhibition of HIF1α expression

Despite a high remission rate after therapy, only 40-50% of acute myeloid leukemia (AML) patients survive 5 years after diagnosis. The main cause of treatment failure is thought to be insufficient eradication of CD34⁺CD38^- AML cells. In order to induce preferential cell death in CD34⁺CD38^- AML cells, two separate events may be necessary: (1) inhibition of survival signals such as nuclear factor kappa-beta (NF-κB) and (2) induction of stress responses such as the oxidative stress response. Therefore, regimens that mediate both effects may be favorable. Deferasirox is a rationally designed oral iron chelator mainly used to reduce chronic iron overload in patients who receive long-term blood transfusions. Our study revealed that clinically relevant concentrations of deferasirox are cytotoxic in vitro to AML progenitor cells, but even more potent against the more primitive CD34⁺CD38^- cell population. In addition, we found that deferasirox exerts its effect, at least in part, by inhibiting the NF-κB/hypoxia-induced factor 1-alpha (HIF1α) pathway and by elevating reactive oxygen species levels. We believe that, pending further characterization, deferasirox can be considered as a potential therapeutic agent for eradicating CD34⁺CD38^- AML cells.

Iron overload in myelodysplastic syndromes: Evidence based guidelines from the Canadian consortium on MDS

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.

Effect of pharmacogenetic markers of vitamin D pathway on deferasirox pharmacokinetics in children

OBJECTIVES

Patients with β-thalassemia major have extremely low vitamin D levels, owing to reduced intestinal absorption, subicteric tint, and/or iron-induced higher pigmentation. We investigated whether some polymorphisms within the VDR, CYP24A1, CYP27B1, and GC genes could play a role in deferasirox pharmacokinetics in a cohort of pediatric patients.

PATIENTS AND METHODS

Eighteen children with β-thalassemia were enrolled. Drug plasma concentrations at the end of dosing interval (Ctrough) and after 0, 2, 4, 6, and 24 h of drug administration were measured by a HPLC-UV method. Allelic discrimination for VDR (TaqI, FokI, BsmI, Cdx2, and ApaI), CYP24A1 (22776, 3999 and 8620), CYP27B1 (2838 and -1260), and GC (1296) single nucleotide polymorphisms was performed by real-time PCR.

RESULTS

CYP24A1 8620 AG/GG group negatively predicted Ctrough in regression analysis (P=0.012). ApaI AA genotype resulted as a negative predictor of Ctrough (P=0.025) and area under the concentration curve (P=0.007); FoKI CC genotype remained as area under the concentration curve positive predictor (P=0.008) and TC/CC group as half-life (t1/2) (P=0.003) and volume of distribution (Vd) (P=0.011) negative one; TaqI TC/CC was retained as a negative predictor of drug maximum concentration (Cmax) (P=0.004). Moreover, GC 1296 TG/GG seemed able to predict lower time to reach drug maximum concentration (Tmax) (P=0.033).

CONCLUSION

Our preliminary experience suggested the potential usefulness of vitamin D pharmacogenetic to better understand deferasirox interindividual variability, also in pediatric patients.

SPAG6 silencing induces apoptosis in the myelodysplastic syndrome cell line SKM‑1 via the PTEN/PI3K/AKT signaling pathway in vitro and in vivo

Apoptosis is a multi-step mechanism of cell self‑destruction for maintaining cellular homeostatic balance. Accumulating evidence indicates that abnormal apoptosis promotes the evolution and progression of myelodysplastic syndromes (MDS). As a novel cancer-testis antigen, sperm‑associated antigen 6 (SPAG6) has been reported to regulate apoptosis through the tumor necrosis factor-related apoptosis-inducing ligand signaling pathway in the MDS cell line SKM‑1. However, the mechanism of the intrinsic cell death pathway for apoptosis induction by SPAG6 silencing is unclear. In the present study, the in vitro effects of SPAG6 silencing were investigated in SKM‑1 cells through extensive biochemical and molecular approaches. Western blotting and reverse transcription-quantitative polymerase chain reaction were used to detect the expression of SPAG6 and activation of PTEN/PI3K/AKT signal pathway. Additionally, SKM‑1 cells transduced with SPAG6 short hairpin RNA (shRNA) lentivirus were treated with the phosphatidylionositol 3-kinase (PI3K) inhibitor LY294002 or pan caspase inhibitor z‑VAD‑fmk and the apoptosis rates were measured by flow cytometry, and the expressions of associated proteins were examined by western blot analysis. A mouse xenograft model was also used to further evaluate the effects of SPAG6 knockdown on inducing tumor apoptosis in vivo. Lentivirus-mediated knockdown of SPAG6 in SKM‑1 cells increased phosphatase and tensin homolog (PTEN) expression and reduced protein kinase B (AKT) phosphorylation, which in turn resulted in cell apoptosis as evidenced by induced myeloid leukaemia cell differentiation protein Mcl‑1 downregulation, cytochrome c release and increased caspase‑9 expression. Consistently, the PI3K inhibitor LY294002 synergistically enhanced apoptosis of SKM‑1 cells when co-administered with SPAG6 shRNA lentivirus. Furthermore, treatment with the pan caspase inhibitor z‑VAD‑fmk failed to prevent PTEN activation upon SPAG6 knockdown, suggesting that SPAG6-regulated PTEN expression was caspase activation-independent. In addition, SPAG6 knockdown was associated with DNMT1 downregulation, implying that SPAG6 may indirectly control PTEN expression via DNA methylation. Furthermore, tumor tissues from nonobese diabetic/severe combined immunodeficient mice inoculated with SPAG6-shRNA lentivirus pre-infected SKM‑1 cells exhibited significantly elevated apoptosis in the extrinsic and intrinsic pathways. These results demonstrate that SPAG6 silencing induces PTEN expression to regulate apoptosis though the PI3K/AKT pathway, indicating that SPAG6 may be a potential therapeutic target for MDS.

Synergistic inhibitory effects of deferasirox in combination with decitabine on leukemia cell lines SKM-1, THP-1, and K-562

A multi-center study from the French Myelodysplastic Syndrome (MDS) Group confirmed that iron chelation therapy is an independent prognostic factor that can increase the survival rate of patients who are suffering from transfusion-dependent low-risk MDS. In this study, we aimed to explore this clinical phenomena in vitro, by exploring the synergistic effect of the iron chelator Deferasirox (DFX) and the DNA methyl transferase inhibitor Decitabine (DAC) in the leukemia cell lines SKM-1, THP-1, and K-562. Treatment with both DFX or DAC promoted apoptosis, induced cell cycle arrest, and inhibited proliferation in all three of these cell lines. The combination of DFX and DAC was much greater than the effect of using either drug alone. DFX showed a synergistic effect with DAC on cell apoptosis in all three cell lines and on cell cycle arrest at the G0/G1 phase in K-562 cells. DFX decreased the ROS levels to varying degrees. In contrast, DAC increased ROS levels and an increase in ROS was also noted when the two drugs were used in combination. Treatment of cells with DAC induced re-expression of ABAT, APAF-1, FADD, HJV, and SMPD3, presumably through demethylation. However the combination of DAC and DFX just had strong synergistic effect on the re-expression of HJV.

To chelate or not to chelate in MDS: That is the question!

Myelodysplastic syndromes (MDS) are a heterogeneous group of hemopathies that exhibit physical manifestations with clinical consequences of bone marrow failure and inherent risk of progression to acute myeloid leukemia. Iron overload (IO) is common in MDS due to chronic transfusion support and disease-related alterations in iron metabolism. IO has been conclusively associated with inferior outcomes among MDS patients. Despite lack of randomized trials showing a survival impact of iron chelation therapy (ICT), ICT is recommended by experts and guidelines for select MDS patients with IO and is often used. The availability of effective oral ICT agents has reignited the controversy regarding ICT use in patients with MDS and IO. Here we summarize the studies evaluating the value of ICT in MDS and suggest a practical approach for use of these therapies. We also highlight controversies regarding use of ICT in MDS and discuss some ongoing efforts to answer these questions.

Iron overload in lower international prognostic scoring system risk patients with myelodysplastic syndrome receiving red blood cell transfusions: Relation to infections and possible benefit of iron chelation therapy

BACKGROUND

An increased incidence of infections and infectious mortality has been reported in myelodysplastic syndromes (MDS) patients receiving red blood cell (RBC) transfusions.

METHODS

We examined incidence of infections requiring antibiotics, antifungal or antiviral medications in transfused lower International Prognostic Scoring System (IPSS) risk MDS patients and whether this differed with iron chelation therapy (ICT).

RESULTS

138 transfused MDS patients were lower IPSS risk. 59 received ICT; median duration was 13 months. There was no significant difference between groups in neutrophil count at first RBC transfusion or first infection. Infections included: bacterial, n = 88; viral; fungal; and mycobacterial; n = 2 each. In ICT and non-ICT patients, respectively, infections were (number [%]): patients, 23 (40.0%) and 22 (27.8%); episodes (median [range]), 2 (1-6) and 2 (1-5); hospitalizations, 16 (27.1%) and 8 (10.1%); and deaths, 0 (0%) and 1 (1.3%), p = NS for all. Median overall survival (OS) from first RBC transfusion was superior in ICT patients, p = 0.01, and remained significant in a multivariate analysis (MVA), p = 0.003. Median time to first infection (TTI) was 27 and 7.8 months, respectively, p < 0.0001, and ICT remained significant for TTI in an MVA, p = 0.02, hazard ratio 0.3. For ICT patients with blast count <5%, TTI was significantly superior (p = 0.004).

CONCLUSIONS

In this retrospective analysis, for lower IPSS risk MDS patients receiving RBC transfusions, though number and type of infections were similar between groups and despite similar neutrophil counts, time to first infection was significantly longer in ICT patients (p < 0.0001). These results should be confirmed in larger, prospective analyses.

Red blood cell transfusion support and management of secondary iron overload in patients with haematological malignancies in the Netherlands: a survey

BACKGROUND AND OBJECTIVES

Evidence-based guidelines on optimal triggers for red blood cell (RBC) transfusion in patients with haematological malignancies exist, but the evidence is weak. Secondary iron overload is an often overlooked chronic complication of RBC transfusions, and also here, guidelines are either lacking or lack international consensus. Our aim was to evaluate the triggers for RBC transfusion support and management of secondary iron overload among haematologists in the Netherlands.

MATERIALS AND METHODS

For this cross-sectional study, all haematologists and haematologists in training in the Netherlands were sent a web-based, 25-question survey including three clinical scenarios. The survey distribution took place between 19 November 2015 and 26 January 2016.

RESULTS

Seventy-seven responses were received (24%), well distributed among community and university hospitals. A wide variation in haemoglobin triggers existed: 5·6-9·5 g/dl (median: 8·0 g/dl). Personalization of this trigger was mostly based on (estimated) cardiopulmonary compensation capacity of patients. About 65% of respondents reported two RBC units per transfusion episode (range 1-3). For monitoring secondary iron overload, serum ferritin was most frequently measured (97%), while a value of 1000-1500 μg/l was the most common cut-off to initiate treatment (39%). For 81% of respondents, phlebotomies were the first choice of treatment, although often the haemoglobin level was considered a limiting factor.

CONCLUSION

Our results confirm large reported variation in daily practice among haematologists in the Netherlands regarding RBC transfusion support and management of secondary iron overload. Future studies providing better evidence are needed to improve guidelines specific for patients with haematological malignancies.

Iron overload in myelodysplastic syndromes (MDS)

Iron overload (IOL) starts to develop in MDS patients before they become transfusion-dependent because ineffective erythropoiesis suppresses hepcidin production in the liver and thus leads to unrestrained intestinal iron uptake. However, the most important cause of iron overload in MDS is chronic transfusion therapy. While transfusion dependency by itself is a negative prognostic factor reflecting poor bone marrow function, the ensuing transfusional iron overload has an additional dose-dependent negative impact on the survival of patients with lower risk MDS. Cardiac dysfunction appears to be important in this context, as a consequence of chronic anemia, age-related cardiac comorbidity, and iron overload. Another potential problem is iron-related endothelial dysfunction. There is some evidence that with increasing age, high circulating iron levels worsen the atherosclerotic phenotype. Transfusional IOL also appears to aggravate bone marrow failure in MDS, through unfavorable effects on mesenchymal stromal cells as well a hematopoietic cells, particularly erythroid precursors. Patient series and clinical trials have shown that the iron chelators deferoxamine and deferasirox can improve hematopoiesis in a minority of transfusion-dependent patients. Analyses of registry data suggest that iron chelation provides a survival benefit for patients with MDS, but data from a prospective randomized clinical trial are still lacking.

Role of CYP24A1, VDR and GC gene polymorphisms on deferasirox pharmacokinetics and clinical outcomes

β-Thalassemia patients develop deficiency in vitamin D absorption and liver hydroxylation, resulting in extremely low calcitriol levels. We explored the role of single-nucleotide polymorphisms (SNPs) involved in vitamin D metabolism, transport and activity on deferasirox pharmacokinetics and outcomes (effectiveness trough levels (C_trough) and the area under the curve (AUC) cutoffs of 20 μg ml^-1 and 360 μg ml^-1 h^-1, respectively; nonresponse AUC limit of 250 μg ml^-1 h^-1). Ninety-nine β-thalassemic patients were enrolled. Drug plasma C_trough and AUC were measured by the high-performance liquid chromatography system coupled with an ultraviolet determination method. Allelic discrimination for VDR, CYP24A1, CYP27B1 and GC gene SNPs was performed by real-time PCR. CYP24A1 22776 TT significantly influenced C_min and negatively predicted it in regression analysis. CYP24A1 3999 CC was associated with C_trough and C_min and was a negative predictor of T_max, whereas CYP24A1 8620 GG seemed to have a role in C_trough, AUC, t_1/2 and C_min, and was an AUC negative predictor factor. Considering treatment outcome, Cdx2 and GC 1296 were retained in regression analysis as AUC efficacy cutoff negative predictors.

Iron chelation therapy in lower IPSS risk myelodysplastic syndromes; which subtypes benefit?

BACKGROUND

Analyses suggest MDS patients with higher serum ferritin levels (SF) have inferior overall survival (OS), in one study across MDS subtypes. Multiple analyses suggest those with high SF receiving iron chelation therapy (ICT) have superior OS, but which MDS subtypes benefit from ICT remains undefined.

METHODS

We performed survival analyses of MDS subtypes by receipt of ICT.

RESULTS

182 MDS were lower IPSS risk and received red blood cell (RBC) transfusions; 63 received ICT. For the entire cohort, receiving ICT independently predicted superior OS in a multivariate analysis (hazard ratio for death 0.3, p=0.01). Features differing for ICT and non-ICT patients, respectively, were: age; IPSS risk group; number of RBC units transfused; and SF, p≤0.03 for all. At a median follow up of 76.5 and 28.4 months, 65.1% and 63.0% were alive. Median OS (months) for ICT and non-ICT patients was: RA, 140.9 and 36.3, p=0.0008; RARS/RARS-t, 133.4 and 73.3, p=0.02. For RCMD/RCMD-RS, p=NS, however, 3 (20%) had significant erythroid improvement with ICT; other subtypes had small numbers.

DISCUSSION

In this retrospective analysis, RA and RARS/RARS-t patients receiving ICT had superior OS to non-ICT patients. These findings should be verified and other MDS subtypes examined in larger prospective analyses.