Overall survival in lower IPSS risk MDS by receipt of iron chelation therapy, adjusting for patient-related factors and measuring from time of first red blood cell transfusion dependence: an MDS-CAN analysis

Iron Overload, Oxidative Stress, and Somatic Mutations in MDS: What Is the Association?

INTRODUCTION

Iron overload (IOL) accumulates in myelodysplastic syndromes (MDS) from expanded erythropoiesis and transfusions. Somatic mutations (SM) are frequent in MDS and stratify patient risk. MDS treatments reversing or limiting transfusion dependence are limited.

METHODS

The literature was reviewed on how IOL and oxidative stress interact with specific SM in MDS to influence cellular physiology. PubMed searches included keywords of each specific mutation combined with iron, oxidative stress, and reactive oxygens species (ROS). Papers relevant to hematopoietic stem/progenitor cells, the bone marrow microenvironment, MDS, AML or other myeloid disorders were preferred. Included were the most frequent SM in MDS, SM of the International Prognostic Scoring System-Molecular (IPSS-M), of familial predisposing conditions and the CMML PSS-molecular.

RESULTS

About 31 SM plus four familial conditions were searched. Discussed are the frequency of each SM, whether function is gained or lost, early or late SM status, a function of the unmutated gene, and function considering iron and oxidative stress.

DISCUSSION

Given limited effective MDS therapies, considering how IOL and ROS interact with SM to influence cellular physiology in the hematopoietic system, increasing bone marrow failure progression or malignant transformation may be of benefit and support optimization of measures to reduce IOL or neutralize ROS.

Low-risk MDS-A spotlight on precision medicine for SF3B1-mutated patients

A deep understanding of the biological mechanisms driving the pathogenesis of myelodysplastic neoplasms (MDS) is essential to develop comprehensive therapeutic approaches that will benefit patient's disease management and quality of life. In this review, we focus on MDS harboring mutations in the splicing factor SF3B1. Clones harboring this mutation arise from the most primitive hematopoietic compartment and expand throughout the entire myeloid lineage, exerting distinct effects at various stages of differentiation. Supportive care, particularly managing anemia, remains essential in SF3B1-mutated MDS. While SF3B1 mutations are frequently linked with ring sideroblasts and iron overload due to impaired erythropoiesis, the current therapeutic landscape fails to adequately address the underlying disease biology, particularly in transfusion-dependent patients, where further iron overload contributes to increased morbidity and mortality. Novel agents such as Luspatercept and Imetelstat have shown promise, but their availability remains restricted and their long-term efficacy is to be investigated. Spliceosome modulators have failed to deliver and inhibitors of inflammatory pathways, including TLR and NF-κB inhibitors, are still under investigation. This scarcity of effective and disease-modifying therapies highlights the unmet need for new approaches tailored to the molecular and genetic abnormalities in SF3B1-mutated MDS. Emerging strategies targeting metabolic mis-splicing (e.g., COASY) with vitamin B5, pyruvate kinase activators, and inhibitors of oncogenic pathways like MYC and BCL-2 represent potential future avenues for treatment, but their clinical utility remains to be fully explored. The current limitations in treatment underscore the urgency of developing novel, more effective therapies for patients with SF3B1-mutated MDS.

How I treat iron overload in adult MDS

ABSTRACT

Although clinical benefits of iron chelation therapy (ICT) in red blood cell (RBC) transfusion-dependent (TD) hereditary anemias such as α-thalassemia major are incontrovertible, the evidence supporting a similar benefit in patients with TD myelodysplastic neoplasms (MDS) and iron overload (IOL) is sometimes debated. MDS presents later in life, has a limited repertoire of life-extending therapies, and patients may have comorbidities acting as competing causes of death. However, refined prognostication identifies patients with MDS with a reasonable life expectancy, and because 50% of patients will ultimately become RBC TD and develop transfusional IOL, ICT should be considered in some. Using illustrative cases, we summarize mechanisms of iron toxicity, strategies for the identification of IOL, and propose definitions of IOL severity. We provide rationale for, and recommend which patients may benefit from, ICT. We discuss currently available chelators, their administration, monitoring, side effects, and their management. Given challenges with the use of iron chelators, we suggest the nuances to be considered when planning chelation initiation to include the rate of iron accumulation, the presence of organ iron and/or dysfunction, and detectable indicators of oxidative stress. Areas for future investigation are identified.

Iron overload in acquired sideroblastic anemias and MDS: pathophysiology and role of chelation and luspatercept

Besides transfusion therapy, ineffective erythropoiesis contributes to systemic iron overload in myelodysplastic syndromes with ring sideroblasts (MDS-RS) via erythroferrone-induced suppression of hepcidin synthesis in the liver, leading to increased intestinal iron absorption. The underlying pathophysiology of MDS-RS, characterized by disturbed heme synthesis and mitochondrial iron accumulation, is less well understood. Several lines of evidence indicate that the mitochondrial transporter ABCB7 is critically involved. ABCB7 is misspliced and underexpressed in MDS-RS, due to somatic mutations in the splicing factor SF3B1. The pathogenetic significance of ABCB7 seems related to its role in stabilizing ferrochelatase, the enzyme incorporating iron into protoporphyrin IX to make heme. Although iron-related oxidative stress is toxic, many patients with MDS do not live long enough to develop clinical complications of iron overload. Furthermore, it is difficult to determine the extent to which iron overload contributes to morbidity and mortality in older patients with MDS, because iron-related complications overlap with age-related medical problems. Nevertheless, high-quality registry studies showed that transfusion dependency is associated with the presence of toxic iron species and inferior survival and confirmed a significant survival benefit of iron chelation therapy. The most widely used iron chelator in patients with MDS is deferasirox, owing to its effectiveness and convenient oral administration. Luspatercept, which can reduce SMAD2/SMAD3-dependent signaling implicated in suppression of erythropoiesis, may obviate the need for red blood cell transfusion in MDS-RS for more than a year, thereby diminishing further iron loading. However, luspatercept cannot be expected to substantially reduce the existing iron overload.

Role of reactive oxygen species in myelodysplastic syndromes

Reactive oxygen species (ROS) serve as typical metabolic byproducts of aerobic life and play a pivotal role in redox reactions and signal transduction pathways. Contingent upon their concentration, ROS production not only initiates or stimulates tumorigenesis but also causes oxidative stress (OS) and triggers cellular apoptosis. Mounting literature supports the view that ROS are closely interwoven with the pathogenesis of a cluster of diseases, particularly those involving cell proliferation and differentiation, such as myelodysplastic syndromes (MDS) and chronic/acute myeloid leukemia (CML/AML). OS caused by excessive ROS at physiological levels is likely to affect the functions of hematopoietic stem cells, such as cell growth and self-renewal, which may contribute to defective hematopoiesis. We review herein the eminent role of ROS in the hematological niche and their profound influence on the progress of MDS. We also highlight that targeting ROS is a practical and reliable tactic for MDS therapy.

[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.

Myelodysplastic syndromes: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

The myelodysplastic syndromes (MDS) are a very heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to acute myelogenous leukemia (AML). MDS occurs more frequently in older males and in individuals with prior exposure to cytotoxic therapy.

DIAGNOSIS

Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy. Information obtained from additional studies such as karyotype, flow cytometry, and molecular genetics is usually complementary and may help refine diagnosis. A new WHO classification of MDS was proposed in 2022. Under this classification, MDS is now termed myelodysplastic neoplasms.

RISK-STRATIFICATION

Prognosis of patients with MDS can be calculated using a number of scoring systems. All these scoring systems include analysis of peripheral cytopenias, percentage of blasts in the bone marrow, and cytogenetic characteristics. The most commonly accepted system is the Revised International Prognostic Scoring System (IPSS-R). Recently, genomic data has been incorporated resulting in the new IPSS-M classification.

RISK-ADAPTED THERAPY

Therapy is selected based on risk, transfusion needs, percent of bone marrow blasts, cytogenetic and mutational profiles, comorbidities, potential for allogeneic stem cell transplantation (alloSCT), and prior exposure to hypomethylating agents (HMA). Goals of therapy are different in lower risk patients than in higher risk and in those with HMA failure. In lower risk, the goal is to decrease transfusion needs and transformation to higher risk disease or AML, as well as to improve survival. In higher risk, the goal is to prolong survival. In 2020, two agents were approved in the US for patients with MDS: luspatercept and oral decitabine/cedazuridine. In addition, currently other available therapies include growth factors, lenalidomide, HMAs, intensive chemotherapy, and alloSCT. A number of phase 3 combinations studies have been completed or are ongoing at the time of this report. At the present time there are no approved interventions for patients with progressive or refractory disease particularly after HMA based therapy. In 2021, several reports indicated improved outcomes with alloSCT in MDS as well as early results from clinical trials using targeted intervention.

The Management of Low-Risk Myelodysplastic Syndromes-Current Standards and Recent Advances

ABSTRACT

The myelodysplastic syndromes (MDSs) are a heterogeneous group of hematologic neoplasms with varied natural histories and prognoses. Specific to this review, treatment of low-risk MDS most often focuses on improving quality of life by correcting cytopenias, as opposed to urgent disease modification to avoid acute myeloid leukemia. These treatments include transfusion support with iron chelation when necessary, growth factors including novel maturation agents such as luspatercept, lenalidomide for del(5q) disease, and, increasingly, low-dose hypomethylating agents. Recent advances in the understanding of the genetic lesions that drive MDS have prompted a reassessment of how low-risk disease is defined and helped to identify a subset of low-risk MDS patients who may benefit from a more aggressive treatment paradigm, including hematopoietic stem cell transplantation.

Erythropoiesis in lower-risk myelodysplastic syndromes and beta-thalassemia

The hematologic disorders myelodysplastic syndromes and beta-thalassemia are characterized by ineffective erythropoiesis and anemia, often managed with regular blood transfusions. Erythropoiesis, the process by which sufficient numbers of functional erythrocytes are produced from hematopoietic stem cells, is highly regulated, and defects can negatively affect the proliferation, differentiation, and survival of erythroid precursors. Treatments that directly target the underlying mechanisms of ineffective erythropoiesis are limited, and management of anemia with regular blood transfusions imposes a significant burden on patients, caregivers, and health care systems. There is therefore a strong unmet need for treatments that can restore effective erythropoiesis. Novel therapies are beginning to address this need by targeting a variety of mechanisms underlying erythropoiesis. Herein, we provide an overview of the role of ineffective erythropoiesis in myelodysplastic syndromes and beta-thalassemia, discuss unmet needs in targeting ineffective erythropoiesis, and describe current management strategies and emerging treatments for these disorders.

Neonatal hemochromatosis with εγδβ-thalassemia: a case report and analysis of serum iron regulators

Background

Neonatal hemochromatosis causes acute liver failure during the neonatal period, mostly due to gestational alloimmune liver disease (GALD). Thalassemia causes hemolytic anemia and ineffective erythropoiesis due to mutations in the globin gene. Although neonatal hemochromatosis and thalassemia have completely different causes, the coexistence of these diseases can synergistically exacerbate iron overload. We report that a newborn with εγδβ-thalassemia developed neonatal hemochromatosis, which did not respond to iron chelators and rapidly worsened, requiring living-donor liver transplantation.

Case presentation

A 1-day-old Japanese boy with hemolytic anemia and targeted red blood cells was diagnosed with εγδβ-thalassemia by genetic testing, and required frequent red blood cell transfusions. At 2 months after birth, exacerbation of jaundice, grayish-white stool, and high serum ferritin levels were observed, and liver biopsy showed iron deposition in hepatocytes and Kupffer cells. Magnetic resonance imaging scans showed findings suggestive of iron deposits in the liver, spleen, pancreas, and bone marrow. The total amount of red blood cell transfusions administered did not meet the criteria for post-transfusion iron overload. Administration of an iron-chelating agent was initiated, but iron overload rapidly progressed to liver failure without improvement in jaundice and liver damage. He underwent living-donor liver transplantation from his mother, after which iron overload disappeared, and no recurrence of iron overload was observed. Immunohistochemical staining for C5b-9 in the liver was positive. Serum hepcidin levels were low and serum growth differentiation factor-15 levels were high prior to living-donor liver transplantation.

Conclusions

We reported that an infant with εγδβ-thalassemia developed NH due to GALD, and that coexistence of ineffective erythropoiesis in addition to erythrocyte transfusions may have exacerbated iron overload. Low serum hepcidin levels, in this case, might have been caused by decreased hepcidin production arising from fetal liver damage due to neonatal hemochromatosis and increased hepcidin-inhibiting hematopoietic mediators due to the ineffective hematopoiesis observed in thalassemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03706-3.

High transferrin saturation predicts inferior clinical outcomes in patients with myelodysplastic syndromes

Iron overload (IO) reflected by elevated ferritin is associated with increased mortality in myelodysplastic syndromes (MDS), however, ferritin is an imperfect metric. Elevated labile plasma iron correlates with clinical outcomes and transferrin saturation (TSAT) >80%, but is not readily measurable. The trajectory of TSAT, and its association with clinical outcomes remain undefined. Canadian MDS registry patients were evaluated. Mean TSAT, mean ferritin and transfusion dose density (TDD) were determined. Survival was evaluated by TSAT and ferritin (<50%, 50-80%, >80%), (≤500 μg/L, 501-800 μg/L, >800 μg/L). In 718 patients, median age was 74 years; 12%, 31%, 29%, 15% and 13% were IPSS-R very low, low, intermediate, high and very high. TSAT and ferritin were moderately correlated (r=0.63, P<0.0001). TSAT increased over time in transfusion- dependent patients (P=0.006). Higher TSAT and ferritin were associated with inferior 5-year overall (OS), progression- free (PFS), and leukemia-free survival (LFS) (P≤0.008) and higher TDD with inferior 5-year OS. TSAT >80% trended with inferior cardiac death-free survival (P=0.053). In univariate analysis, age, IPSS-R, blast percentage by Eastern Cooperative Oncology Group Performance Status, frailty, Charlson Comorbidity Index, iron chelation (Y/N), TDD, TSAT and ferritin were significantly associated with inferior OS. By multivariable analysis, TSAT >80% (P=0.007) remained significant for OS (R2 30.3%). In MDS, TSAT >80% and ferritin >800 μg/L portended inferior OS, PFS and LFS. TSAT may indicate the presence of oxidative stress, and is readily measurable in a clinical setting. The relationship between TSAT and cardiac death-free survival warrants further study.

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.

Exploring the rationale for red cell transfusion in myelodysplastic syndrome patients: emerging data and future insights

INTRODUCTION

Anemia is often present in mostly elderly patients with myelodysplastic syndromes (MDS), and is associated with a poorer outcome. Although Red blood cell (RBC) transfusions are the most immediate treatment, waiting for the response to disease-specific therapy, or in case of non-response, the choice of the optimal transfusion regimen is still controversial.

AREAS COVERED

The main objectives of RBC transfusion are the control of anemia-related symptoms and complications and the improvement of functional status and of health-related quality of life (HRQoL). However, RBC transfusions are associated with several negative clinical consequences, mainly adverse transfusion reactions and iron overload, which can be counteracted by iron chelation therapy. Recent few pilot prospective trials have shown a benefit, in terms of HRQoL, of more liberal transfusion regimens, with higher haemoglobin (Hb) targets, compared to conventional restrictive regimens, but these results need confirmation by larger studies.

EXPERT OPINION

: A patient-oriented RBC transfusion therapy in MDS patients must take into account several laboratory (Hb), clinical (age, comorbidities), psychological, family and social factors, and evaluation of HRQoL should become a fundamental parameter in assessing the clinical benefit of therapy. Many questions remain to be clarified, including why some patients report little benefit from transfusions.

Assessing the Prognosis of Patients with Myelodysplastic Syndromes (MDS)

Prognostic stratification in patients with myelodysplastic syndrome (MDS) relies on a number of key factors. Combining such patient-related and disease-related prognostic parameters into useful assessment tools remains a challenge. The most widely used scoring systems include the international prognostic scoring system (IPSS), the revised IPSS (IPSS-R), the World Health Organization (WHO) Prognostic Scoring System (WPSS), and the new molecular IPSS (IPSS-M). Similar to the IPSS-R and the IPSS-M, the chronic myelomonocytic leukemia (CMML) prognostic scoring system (CPSS) and the CPSS molecular (CPSS-mol) are powerful and reliable prognostic tools that help to assess the individual prognosis of patients with CMML. The well-established prognostic assessment of MDS and CMML may be further augmented by additional disease-related parameters, such as somatic mutations, or patient-related factors, such as comorbidities. In this article, we briefly describe useful prognostic scoring systems for myelodysplastic syndromes and identify some open questions that require further investigation.

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.

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.

Early transplantation-related mortality after allogeneic hematopoietic cell transplantation in patients with acute leukemia

Background

Transplantation-related mortality (TRM) is a major obstacle in allogeneic hematopoietic cell transplantation (allo-HCT). Approximately 60–80% of TRM occurs early, within 100 days of transplantation.

Methods

This was a nationwide population cohort study involving 5395 patients with acute leukemia who underwent allo-HCT between 2003 and 2015. Patient data were collected from the Korean National Health Insurance Service database. We investigated the cumulative incidence rates (CIRs) of early TRM at 50 and 100 days.

Results

The CIRs of early TRM at 50 and 100 days were 2.9 and 8.3%, respectively. There was no decrease in the CIRs of early TRM over time. The early mortality was significantly higher in patients with more than 9 months between the diagnosis and transplantation (CIRs of TRM at 50, 100 days; 6.0, 13.2%), previous transplantations (CIRs of TRM at 50, 100 days; 9.4, 17.2%), and cord blood transplantation (CIRs of TRM at 50, 100 days; 6.1, 8.3%). The early TRM was significantly lower in patients who received iron chelation before transplantation (CIRs of TRM at 50, 100 days; 0.3, 1.8%).

Conclusions

In conclusion, the overall CIR of early TRM was less than 10%. The predictable factors for early TRM included age, time from diagnosis to transplantation, the number of prior transplantations, the graft source, and previous iron chelation therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07897-3.

Clinical Management of Anemia in Patients with Myelodysplastic Syndromes: An Update on Emerging Therapeutic Options

For the majority of patients with lower-risk myelodysplastic syndrome (LR-MDS), one of the primary clinical goals is to alleviate the symptoms associated with the resultant cytopenias and to minimize the transfusion burden. While supportive red blood cell (RBC) transfusions and erythropoiesis-stimulating agents (ESAs) may lead to clinical improvement, frequent transfusions are often complicated by iron overload and decreased quality of life; furthermore, most patients either do not respond to ESAs or will eventually develop resistance. As such, there is a great need for further therapeutic options in the management of anemia related to MDS. Several additional therapeutics are now available in select patients with LR-MDS and symptomatic anemia including luspatercept, lenalidomide, and immunosuppressive therapy. Furthermore, several novel agents are currently in development to address this area of clinical need such as imetelstat and roxadustat. In this article, we review the currently available therapeutic options for symptomatic anemia in LR-MDS as well as review the therapeutic agents in development.

Myelodysplastic syndromes: 2021 update on diagnosis, risk stratification and management

DISEASE OVERVIEW

The myelodysplastic syndromes (MDS) are a very heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to acute myelogenous leukemia (AML). Myelodysplastic syndromes occur more frequently in older males and in individuals with prior exposure to cytotoxic therapy.

DIAGNOSIS

Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy. Information obtained from additional studies such as karyotype, flow cytometry and molecular genetics is usually complementary and may help refine diagnosis.

RISK-STRATIFICATION

Prognosis of patients with MDS can be calculated using a number of scoring systems. In general, all these scoring systems include analysis of peripheral cytopenias, percentage of blasts in the bone marrow and cytogenetic characteristics. The most commonly accepted system is the Revised International Prognostic Scoring System (IPSS-R). Somatic mutations can help define prognosis and therapy.

RISK-ADAPTED THERAPY

Therapy is selected based on risk, transfusion needs, percent of bone marrow blasts, cytogenetic and mutational profiles, comorbidities, potential for allogeneic stem cell transplantation (alloSCT) and prior exposure to hypomethylating agents (HMA). Goals of therapy are different in lower-risk patients than in higher-risk individuals and in those with HMA failure. In lower-risk MDS, the goal is to decrease transfusion needs and transformation to higher risk disease or AML, as well as to improve survival. In higher-risk disease, the goal is to prolong survival. In 2020, we witnessed an explosion of new agents and investigational approaches. Current available therapies include growth factor support, lenalidomide, HMAs, intensive chemotherapy and alloSCT. Novel therapeutics approved in 2020 are luspatercept and the oral HMA ASTX727. At the present time, there are no approved interventions for patients with progressive or refractory disease particularly after HMA-based therapy. Options include participation in a clinical trial, cytarabine-based therapy or alloSCT.

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.

Which lower risk myelodysplastic syndromes should be treated with allogeneic hematopoietic stem cell transplantation?

Indications of allogeneic hematopoietic stem cell transplantation (HSCT) remain controversial in patients with lower risk myelodysplastic syndrome. We review prognostic factors in lower risk MDS, delineating patients with relatively poor risk who may potentially benefit from HSCT during the disease course. Results of HSCT in those patients, and main efforts to decrease non-relapse mortality (NRM) are detailed. Prospective studies are needed to determine more precisely which lower risk MDS patients may benefit from transplantation.

Myelodysplastic syndromes: moving towards personalized management

The myelodysplastic syndromes (MDS) share their origin in the hematopoietic stem cell but have otherwise very heterogeneous biological and genetic characteristics. Clinical features are dominated by cytopenia and a substantial risk for progression to acute myeloid leukemia. According to the World Health Organization, MDS is defined by cytopenia, bone marrow dysplasia and certain karyotypic abnormalities. The understanding of disease pathogenesis has undergone major development with the implementation of next-generation sequencing and a closer integration of morphology, cytogenetics and molecular genetics is currently paving the way for improved classification and prognostication. True precision medicine is still in the future for MDS and the development of novel therapeutic compounds with a propensity to markedly change patients' outcome lags behind that for many other blood cancers. Treatment of higher-risk MDS is dominated by monotherapy with hypomethylating agents but novel combinations are currently being evaluated in clinical trials. Agents that stimulate erythropoiesis continue to be first-line treatment for the anemia of lower-risk MDS but luspatercept has shown promise as second-line therapy for sideroblastic MDS and lenalidomide is an established second-line treatment for del(5q) lower-risk MDS. The only potentially curative option for MDS is hematopoietic stem cell transplantation, until recently associated with a relatively high risk of transplant-related mortality and relapse. However, recent studies show increased cure rates due to better tools to target the malignant clone with less toxicity. This review provides a comprehensive overview of the current status of the clinical evaluation, biology and therapeutic interventions for this spectrum of disorders.

Transfusional iron overload in patients with myelodysplastic syndromes: A 10-year retrospective survey from a French general hospital

We retrospectively assessed the characteristics of 165 MDS patients from our institution having received at least 20 RBC units. In the vast majority of them various comorbidities (range: 1-6 per patient) were registered including mainly cardiovascular disorders. Serum ferritin was over 1000μg/L in about half of tested individuals. A chelator agent was initiated in 43.6% of patients (mainly low-risk MDS). Transformation in AML occurred in 46 cases (27.8%). Overall, 112 patients died during follow up. The cause of death was documented in 65 cases and included mainly MDS or AML resistance to therapy. There was a context of bacterial or fungal-related sepsis in 35.3% of cases. We noticed a correlation between survival and number of RBC transfusions. Median OS from the 20th RBC unit was significantly prolonged among the chelated subgroup. Consequences of transfusional iron overload and chelation need to be clarified in MDS patients.

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.

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.

Impact of transfusion on survival in patients with myelodysplastic syndromes: Current knowledge, new insights and transfusion clinical practice

Red Blood Cell (RBC) transfusion dependence is a prevalent consequence of anaemia in patients with lower risk Myelodysplastic Syndromes (MDS). These patients have shorter survival compared to patients responding to Erythropoiesis-stimulating agents (ESA), raising the question of potential negative effects of chronic RBC transfusions on MDS prognosis, independently of IPSS-R. Besides commonly identified complications of transfusions like iron toxicity or cardiac events, oxidative stress could be a risk factor for ineffective haematopoiesis. Recently, physicochemical changes of RBC during storage have been described. These changes called storage lesions could play a role in immunomodulation in vivo. We review the currently identified sources of potential impact on transfusion-associated effects in MDS patients and we discuss the unexplored potential role of erythrocyte-derived-extracellular vesicles. They could amplify impairment of haematopoiesis in addition to the negative intrinsic effects underlying the pathology in MDS. Thus, chronic RBC transfusions appear to potentially impact the outcome of MDS.

Integrating patient-centered factors in the risk assessment of MDS

Myelodysplastic syndromes are clonal myeloid neoplasms that primarily present in older adults. Although leukemia develops in approximately 25% to 30% of individuals, the significantly shortened survival in this population is attributed more commonly to nonleukemic causes. The current prognostic scoring systems for leukemia and overall survival based on disease characteristics are becoming increasingly sophisticated and accurate with the incorporation of molecular data. The addition of patient-related factors such as comorbidity, disability, frailty, and fatigue to these new models may improve their predictive power for overall survival, treatment toxicity, and health care costs. To improve the generalizability of clinical trial results to the real world, geriatric assessment testing should become a standard of care in MDS clinical trials.

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.

Novel therapies in low- and high-risk myelodysplastic syndrome

Introduction: Myelodysplastic syndromes (MDS) comprise a heterogeneous group of myeloid neoplasms with diverse clinical courses. The revised version of the international prognostic scoring system (IPSS-R) provides risk stratification into 5 different groups. Areas covered: For lower-risk patients, red blood cell transfusions and iron chelation are the backbone of supportive care. In addition, erythropoiesis-stimulating agents (ESA) are used to ameliorate anemia. Lenalidomide is approved for the treatment of lower-risk patients with del(5q) who are transfusion-dependent. Patients with higher-risk disease should be offered allogeneic stem cell transplantation whenever possible. If they are unfit for transplantation or an appropriate donor cannot be found, hypomethylating agents may be used. Expert opinion: New therapeutic options for lower-risk patients include thrombopoietin analogues, the TGF-beta family ligand trapping drug Luspatercept, and the telomerase inhibitor Imetelstat. Combinations of hypomethylating agents (HMA) with other compounds, and inhibitors of bcl2, such as venetoclax are being developed for higher-risk patients. Finally, hypomethylating agents in combination with donor lymphocytes may lead to long-term remission following molecular or hematological relapse after allogeneic SCT.

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.

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.

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.

Tolerability and efficacy of deferasirox in patients with transfusional iron overload: results from a German 2-year non-interventional study

BACKGROUND

Iron overload (IOL) due to repetitive transfusions of packed red blood cells (pRBC) has a major impact on morbidity and mortality in patients with inherited bone marrow failure syndromes and hemoglobinopathies such as thalassemia and sickle cell disease. However, whether IOL influences the outcome of elderly patients with myeloid malignancies is not yet clear. Moreover, clinical trials have reported high drop-out rates during treatment with the oral iron chelator deferasirox (DFX).

AIM

Here we report the results of a 2-year prospective observational study that aimed at describing the routine use of DFX in patients with hematological malignancies with regard to safety, efficacy and handling of the drug in a routine setting.

RESULTS

A total of 406 patients were included. 58% of the patients were male. Most of the patients had myelodysplastic syndromes (MDS) (68%) and myeloproliferative neoplasms (MPN) (14%). Median time from first transfusion to study enrollment was 1.1 years (0-25.5 years) and most patients were chelation naive (91%) at enrollment. With regard to transfusion burden, most of the patients were moderately or mildly transfusion-dependent with 53% receiving 2-4 and 27% receiving less than 2 units of pRBC per month. Serum ferritin decreased from a mean of 2305 μg/l (± 1449 μg/l) to a mean of 1910 μg/l (± 1529 μg/l) at 24 months. There was no substantial change in transfusion-dependence during the observation period. Dose adjustments were reported in 48% of the patients with dose-escalation strategies being the most frequent reason for dosage increases (49%). The median observation time was 355 days (5-1080 days). Median duration of exposure to DFX was 322 days (2-1078 days). Two-hundred and ninety (72%) patients discontinued the trial prematurely after a median time of 235 days (1-808 days). Death (29%) and adverse events (23%) were the main reasons for discontinuation. Eleven percent of the patients discontinued treatment due to sufficient decrease in serum ferritin. Most frequent adverse events were decrease in creatinine clearance (22%), increase in serum creatinine (18%) and diarrhea (16%).

CONCLUSION

This descriptive trial confirms the efficacy of DFX in decreasing the serum ferritin. Moreover, the high drop-out rates seen in prospective trials are recapitulated in this study, which can be attributed to adverse events in a substantial proportion of patients.

Infections in Myelodysplastic Syndrome in Relation to Stage and Therapy

Infections remain a significant problem in myelodysplastic syndromes (MDS) in treated as well in non-treated patients and assume a particular complexity. The susceptibility to infections is due, in the absence of intensive chemotherapies, mainly to functional defects in the myeloid lineage with or without neutropenia. Furthermore, MDS includes a heterogeneous group of patients with very different prognosis, therapy and risk factors regarding survival and infections. You should distinguish risk factors related to the disease, like as neutrophils function impairment, neutropenia, unfavorable cytogenetics and bone marrow insufficiency; factors related to the patient, like as age and comorbidities, and factors related to the therapy. When the patients with MDS are submitted to intensive chemotherapy with and without hematopoietic stem cell transplantation (HSCT), they have a risk factor for infection very similar to that of patients with acute myeloid leukemia (AML), and mostly related to neutropenia. Patients with MDS treated with supportive therapy only or with demethylating agent or lenalidomide or immunosuppressive drugs should have a tailored approach. Most of the infections in MDS originate from bacteria, and the main risk factors are represented by neutropenia, thrombocytopenia, and unfavorable cytogenetics. Thus, it is reasonable to give antibacterial prophylaxis to patients who start the therapy with demethylating agents with a number of neutrophils <500 × 10⁹/L, or with thrombocytopenia and unfavorable cytogenetics. The antifungal prophylaxis is not considered cost/benefit adequate and should be taken into consideration only when there is an antecedent fungal infection or presence of filamentous fungi in the surveillance cultures. Subjects submitted to immunosuppression with ATG+CSA have a high rate of infections, and when severely neutropenic should ideally be nursed in isolation, should be given prophylactic antibiotics and antifungals, regular mouth care including an antiseptic mouthwash.

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

INTRODUCTION

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

Effect of deferasirox + erythropoietin vs erythropoietin on erythroid response in Low/Int-1-risk MDS patients: Results of the phase II KALLISTO trial

OBJECTIVES

Erythropoiesis-stimulating agents (ESAs) remain first-choice to treat symptomatic anemia and delay transfusion dependence in most patients with lower-risk myelodysplastic syndromes (MDS) without del(5q). Deferasirox increased erythroid responses in some lower-risk MDS patients in clinical trials, and adding low-dose deferasirox to ESA treatment may further improve erythroid response.

METHODS

KALLISTO (NCT01868477) was a randomized, open-label, multicenter, phase II study. Lower-risk MDS patients received deferasirox at 10 mg/kg/d (dispersible tablets) or 7 mg/kg/d (film-coated tablets) plus erythropoietin (n = 11), or erythropoietin alone (n = 12) for 24 weeks. The primary endpoint was the between-group difference in erythroid response within 12 weeks.

RESULTS

Erythroid response occurred in 27.3% of patients receiving deferasirox plus erythropoietin vs 41.7% of patients receiving erythropoietin alone within 12 weeks (difference 14.4%; 95% CI -24.0, 48.16). Within 24 weeks, the hematologic response rate was 27.3% with deferasirox plus erythropoietin vs 50% with erythropoietin alone, and hematologic improvement rates were 45.5% vs 100%. Deferasirox plus erythropoietin was generally well tolerated.

CONCLUSIONS

In this small pilot study, combining low-dose deferasirox with erythropoietin did not improve erythroid response. It remains of interest to investigate early chelation approaches with even lower deferasirox doses plus erythropoietin in lower-risk MDS patients before the onset of transfusion dependence.

Iron toxicity - Its effect on the bone marrow

Excess iron can be extremely toxic for the body and may cause organ damage in the absence of iron chelation therapy. Preclinical studies on the role of free iron on bone marrow function have shown that iron toxicity leads to the accumulation of reactive oxygen species, affects the expression of genes coding for proteins that regulate hematopoiesis, and disrupts hematopoiesis. These effects could be partially attenuated by iron-chelation treatment with deferasirox, suggesting iron toxicity may have a negative impact on the hematopoietic microenvironment. Iron toxicity is of concern in transfusion-dependent patients. Importantly, iron chelation with deferasirox can cause the loss of transfusion dependency and may induce hematological responses, although the mechanisms through which deferasirox exerts this action are currently unknown. This review will focus on the possible mechanisms of toxicity of free iron at the bone marrow level and in the bone marrow microenvironment.

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.

Diagnosis, management and response criteria of iron overload in myelodysplastic syndromes (MDS): updated recommendations of the Austrian MDS platform

INTRODUCTION

Despite the availability of effective iron chelators, transfusion-related morbidity is still a challenge in chronically transfused patients with myelodysplastic syndromes (MDS). In these patients, transfusion-induced iron overload may lead to organ dysfunction or even organ failure. In addition, iron overload is associated with reduced overall survival in MDS. Areas covered: During the past 10 years, various guidelines for the management of MDS patients with iron overload have been proposed. In the present article, we provide our updated recommendations for the diagnosis, prevention and therapy of iron overload in MDS. In addition, we propose refined treatment response criteria. As in 2006 and 2007, recommendations were discussed and formulated by participants of our Austrian MDS platform in a series of meetings in 2016 and 2017. Expert commentary: Our updated recommendations should support early recognition of iron overload, optimal patient management and the measurement of clinical responses to chelation treatment in daily practice.

Myelodysplastic syndromes: 2018 update on diagnosis, risk-stratification and management

DISEASE OVERVIEW

The myelodysplastic syndromes (MDS) are a very heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to acute myelogenous leukemia (AML). MDS occurs more frequently in older males and in individuals with prior exposure to cytotoxic therapy.

DIAGNOSIS

Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy. Information obtained from additional studies such as karyotype, flow cytometry or molecular genetics is usually complementary and may help refine diagnosis.

RISK-STRATIFICATION

Prognosis of patients with MDS can be calculated using a number of scoring systems. In general, all these scoring systems include analysis of peripheral cytopenias, percentage of blasts in the bone marrow and cytogenetic characteristics. The most commonly used system is probably the International Prognostic Scoring System (IPSS). IPSS is now replaced by the revised IPSS-R score. Although not systematically incorporated into new validated prognostic systems, somatic mutations can help define prognosis and should be considered as new prognostic factors.

RISK-ADAPTED THERAPY

Therapy is selected based on risk, transfusion needs, percent of bone marrow blasts and cytogenetic and mutational profiles. Goals of therapy are different in lower risk patients than in higher risk. In lower risk, the goal is to decrease transfusion needs and transformation to higher risk disease or AML, as well as to improve survival. In higher risk, the goal is to prolong survival. Current available therapies include growth factor support, lenalidomide, hypomethylating agents, intensive chemotherapy and allogeneic stem cell transplantation. The use of lenalidomide has significant clinical activity in patients with lower risk disease, anemia and a chromosome 5 alteration. 5-azacitidine and decitabine have activity in both lower and higher-risk MDS. 5-azacitidine has been shown to improve survival in higher risk MDS. A number of new molecular lesions have been described in MDS that may serve as new therapeutic targets or aid in the selection of currently available agents. Additional supportive care measures may include the use of prophylactic antibiotics and iron chelation.

MANAGEMENT OF PROGRESSIVE OR REFRACTORY DISEASE

At the present time there are no approved interventions for patients with progressive or refractory disease particularly after hypomethylating based therapy. Options include participation in a clinical trial or cytarabine based therapy and stem cell transplantation.