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

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.

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

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

The relationship between serum ferritin level and fibrosis and splenomegaly in myelofibrosis

INTRODUCTION

Myelofibrosis (MF) is a disease in which the grade of bone marrow fibrosis increases in proportion to the degree of extramedullary hematopoiesis and splenomegaly. Associated with increased cytokines and inflammation, anemia deepens and an increase in serum ferritin levels is also expected. There are no studies addressing the relationship between ferritin and splenomegaly or fibrosis. In this study, the relationship between serum ferritin level and splenomegaly and bone marrow fibrosis was examined.

MATERIAL AND METHOD

The study was performed retrospectively in 46 MF cases diagnosed between 2012 and 2020. MF was divided into 3 separate subgroups: Primary myelofibrosis, secondary myelofibrosis and myeloproliferative neoplasms (MDS/MPN) with myelodsplastic syndrome.

RESULTS

Thirty (28.3%) of cases were PMF, 26 (56.5%) were SMF and 7 (15.2%) were MDS/MPN. There was no relation found between serum ferritin and splenomegaly in none of the cases or subgroup analysis (for PMF p: 0.564, for SMF p: 0.192, for MDS/MPN p: 0.364). There was a statistically significant relationship between serum ferritin and marrow fibrosis within the group of ages 60 years and older (p: 0.016).

DISCUSSION AND CONCLUSION

Disruption of hematopoiesis and progressive splenomegaly causes an increase in iron stores associated with an increased need for transfusion. This causes iron-related organ toxicity and bone marrow hematopoiesis disruption, leading to an increase in morbidity. We see that a significant relationship between ferritin and fibrosis has been revealed in the group aged 60 years and older. It is an unprecedented study in the literature in terms of both examining the relationship ferritin and fibrosis or splenomegaly and its results.

The role of allogeneic stem-cell transplant in myelofibrosis in the era of JAK inhibitors: a case-based review

Allogeneic hematopoietic stem-cell transplantation (HSCT) is, at present, the only potentially curative therapy for myelofibrosis (MF). Despite many improvements, outcomes of HSCT are still burdened by substantial morbidity and high transplant-related mortality. Allogeneic transplant is generally considered in intermediate-2 and high-risk patients aged <70 years, but the optimal selection of patients and timing of the procedure remains under debate, as does as the role of JAK inhibitors in candidates for HSCT. Starting from a real-life clinical case scenario, herein we examine some of the crucial issues of HSCT for MF in light of recent refinements on MF risk stratification, data on the use of ruxolitinib before and after transplant and findings on the impact of different conditioning regimens and donor selection.

Deferasirox in the treatment of iron overload during myeloproliferative neoplasms in fibrotic phase: does ferritin decrement matter?

Few data are available on the treatment with DFX in patients with transfusion dependent Ph- Myeloproliferative Neoplasms in fibrotic phase. Here we report 48MPNpatients and iron overload treated with DFX. Starting DFX dose was 20 mg/Kg in 23 patients, 15 mg/Kg in 20 patientsand 10 mg/Kg in 5 patients. After a median treatment of 27.6 months, 5 patients achieved ferritin<500 ng/ml, 11 < 1000 ng/ml and 3 a reduction >50% of basal ferritin with a global response rate of 41%. As to hematological improvement, 9/47 patients (19.1%) showed a persistent rise of Hb>1.5 g/dl, with disappearance of transfusion requirement in 6 cases. The median OS from DFX initiation in patients with chelation response was 61.0 months compared to 15.8 months in patients without chelation efficacy. Treatment with DFX is feasible and effective in MPN with iron overload and a hematological improvement can occur in a sizeable rate of patients.

Sustained Erythroid Response in a Patient with Myelofibrosis Receiving Concomitant Treatment with Ruxolitinib and Deferasirox

Iron overload (IOL) due to transfusion-dependent anemia is a serious adverse effect in patients with myelofibrosis (MF). Recent studies have shown that the oral iron chelator deferasirox may prevent multiple organ damage due to IOL in MF. However, it is not clear whether deferasirox may contribute to revert transfusion-dependent anemia. Here, we present a patient with transfusion-dependent intermediate-2 MF according to the International Prognostic Scoring System treated with ruxolitinib in combination with deferasirox. In addition to a reduced serum ferritin level, the patient required less blood transfusions, ultimately resulting in long-lasting transfusion-free survival.

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.

Treatment of Myelofibrosis: Old and New Strategies

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

Historical views, conventional approaches, and evolving management strategies for myeloproliferative neoplasms

The classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPN), which include essential thrombocythemia, polycythemia vera, and myelofibrosis (MF), are in a new era of molecular diagnosis, ushered in by the identification of the JAK2(V617F) and cMPL mutations in 2005 and 2006, respectively, and the CALR mutations in 2013. Coupled with increased knowledge of disease pathogenesis and refined diagnostic criteria and prognostic scoring systems, a more nuanced appreciation has emerged of the burden of MPN in the United States, including the prevalence, symptom burden, and impact on quality of life. Biological advances in MPN have translated into the rapid development of novel therapeutics, culminating in the approval of the first treatment for MF, the JAK1/JAK2 inhibitor ruxolitinib. However, certain practical aspects of care, such as those regarding diagnosis, prevention of vascular events, choice of cytoreductive agent, and planning for therapies, present challenges for hematologists/oncologists, and are discussed in this article.

Effect of deferasirox on iron overload in patients with transfusion-dependent haemoglobinopathies

BACKGROUND

Patients with haematopoietic disorders requiring long-term blood transfusions are at risk of iron overload. This study aimed to investigate the efficacy and safety of long-term deferasirox monotherapy in patients with transfusion-dependent anaemia in the routine clinical practice setting.

METHODS

This was a retrospective analysis of patients who commenced deferasirox therapy at the Hospital Bianchi Melacrino Morelli in Reggio Calabria, Italy. Data collected included cardiac and hepatic iron load (assessed by magnetic resonance imaging); left ventricular ejection fraction (LVEF). Patients were divided into two groups for analysis: group A (baseline information collected prior to deferasirox initiation) and group B (baseline information collected after deferasirox initiation).

RESULTS

Forty-six patients were included (group A: n=25; group B: n=21). The overall population was 63% male, with a mean age of 33 years. The majority of patients (65%) had thalassaemia major. In the overall population, cardiac iron levels between the baseline and first follow-up visits improved in both groups A and B (29.2 vs. 32.5 ms; p=0.04 and 28.4 vs. 31.4 ms; p=0.038). Liver iron levels improved significantly from baseline to visit 1 in group A (7.2 vs. 12.1 ms; p<0.004) and from baseline to visit 3 (6.9 vs. 10.7; p=0.049) in group B. Generally, there was no correlation between cardiac and liver iron levels. LVEF remained stable throughout the study period. Deferasirox was well tolerated and was not associated with significant adverse events.

CONCLUSION

Long-term treatment with deferasirox is effective and safe in patients with transfusion-dependent haemoglobinopathies monitored in the clinical practice setting.

Chelation efficacy and erythroid response during deferasirox treatment in patients with myeloproliferative neoplasms in fibrotic phase

At present, very few data are available on deferasirox (DFX) in the treatment of patients with Philadelphia-negative myeloproliferative neoplasms in fibrotic phase (FP-MPN) and transfusion dependence. To address this issue, a retrospective analysis of 28 patients (22 male and 6 female) with FP-MPN and iron overload secondary to transfusion dependence was performed, based on patients enrolled in the database of our regional cooperative group who received treatment with DFX. DFX was started after a median interval from diagnosis of 12.8 months (IR 7.1-43.1) with median ferritin values of 1415 ng/mL (IR 1168-1768). Extra-hematological toxicity was reported in 16 of 28 patients (57.1%), but only two patients discontinued treatment due to toxicity. Among 26 patients evaluable for response (≥6 months of treatment), after a median treatment period of 15.4 months (IR 8.1-22.3), 11 patients (42.3%) achieved a stable and consistent reduction in ferritin levels <1000 ng/mL. As for hematological improvement, 6 of 26 patients (23%) showed a persistent (>3 months) rise of Hb levels >1.5 g/dL, with disappearance of transfusion dependence in four cases. Treatment with DFX is feasible and effective in FP-MPN with iron overload. Moreover, in this setting, an erythroid response can occur in a significant proportion of patients.

[MRI monitoring in diagnosis and follow-up of iron overload]

目的

探索磁共振成像技术（MRI）在铁过载患者诊断和随访中的应用。

方法

回顾性分析北京协和医院2011年7月至2014年3月临床上怀疑有铁过载的患者107例，通过MRI技术测定其肝脏、心脏及胰腺T2*值，同时检测了血清铁蛋白（SF)、转铁蛋白饱和度、输血量及其他实验室指标，比较脏器T2*值与SF、输血量的关系；对其中10例经过祛铁治疗的患者进行随访，探索治疗后SF及T2*值的改变。

结果

①男65例，女42例，中位年龄51(8~77)岁。诊断为骨髓增生异常综合征50例，再生障碍性贫血36例，骨髓纤维化10例，血色病7例，β地中海贫血携带者4例。②肝脏T2*值和SF之间呈低度相关(r=0.120，P=0.001)，心脏T2*值与SF无相关性(r=0.012，P=0.289)；肝脏和心脏T2*值均与输血量无相关性（分别为r=0.019，P=0.175；r=0.000，P=0.845）；肝脏T2*值与心脏T2*值之间无相关性(r=0.015,P=0.235)。③70例患者同时接受肝脏、心脏和胰腺T2*值检测，胰腺T2*值与SF呈低度相关(r=0.061,P=0.039)，与输血量无相关性(r=0.000，P=0.960)；胰腺T2*值与肝脏T2*值无相关性(r=0.047，P=0.071)，而与心脏T2*值呈低度相关(r=0.110，P=0.005)。④其中10例患者进行了规律足量祛铁治疗，治疗前、后SF水平明显下降，分别为（2 566.5±1 152.2)µg/L、(1 473.4±803.0)µg/L(P=0.001)；治疗前、后肝脏T2*值变化不大，分别为（6.0±5.1) ms、(6.3±6.0)ms(P=0.629)。

结论

各脏器铁过载的程度明显不同，MRI定量检测较SF更好地反映脏器间铁过载程度的差异；规律的祛铁治疗在半年内对SF的变化有显著影响，但对肝脏T2*值影响不大，可能需要更长时间的祛铁治疗才能观察到脏器铁沉积的改善。