Efficacy and safety of oral deferasirox treatment in the posttransplant period for patients who have undergone allogeneic hematopoietic stem cell transplantation (alloHSCT)

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

BACKGROUND

Studies on the increased body iron load in patients with thalassemia major have thoroughly demonstrated the problems caused by iron overload. In patients who undergo hematopoietic stem cell transplantation (HSCT) as curative therapy, iron overload continues long after transplantation. There are few pediatric studies on chelation therapy in the posttransplant period. In this study, we present the outcomes of our patients who received posttransplant oral chelation therapy.

PATIENTS AND METHODS

This retrospective observational study evaluated the outcomes of pediatric patients with thalassemia major who used oral chelation therapy after allogeneic HSCT at the Akdeniz University Pediatric Bone Marrow Unit between January 2008 and October 2019.

RESULTS

Deferasirox therapy was initiated in 58 pediatric patients who underwent HSCT for thalassemia. Pretreatment mean serum ferritin was 2166±1038 ng/mL. Treatment was initiated at a mean of 12±6.7 months after transplantation and continued for a mean of 15.7±11.5 months. At treatment discontinuation, the mean serum ferritin was 693±405 ng/mL and the mean reduction was -1472.75±1121.09 ng/mL (P<0.001 vs. posttreatment). Serum ferritin was below 500 ng/mL in 52% of the patients at treatment discontinuation. Manageable side effects such as nausea, vomiting, liver enzyme elevation, and proteinuria were observed in 17% of the patients, while one patient developed ototoxicity.

CONCLUSIONS

Deferasirox therapy effectively reduces iron overload in the posttransplant period. Studies evaluating the effects of early treatment on the graft may help to establish guidelines for posttransplant chelation therapy. Clear guidelines are needed regarding when to initiate and discontinue treatment.

Iron overload in the HCT patient: a review

Iron overload (IO) is common in hematologic malignancies and hemoglobinopathies, largely due to red cell transfusion burden. End-organ damage from IO occurs via reactive oxygen species-mediated pathways. The impact of pretransplant IO on hematopoietic cell transplant (HCT) morbidity and mortality remains contentious; studies have shown mixed results, possibly due to variability in study population and design, as well as markers of IO. Ferritin has served as a traditional circulating marker of total body IO, but liver iron content by MRI appears to be a better marker of end-organ involvement. Novel surrogate markers including hepcidin, marrow Prussian blue staining, and labile plasma iron levels may prove to be more specific for HCT complications. Posttransplant phlebotomy, chelation, or both in combination remains the mainstays of treatment, though may ultimately be supplanted by pretransplant or peri-transplant use of bone marrow maturation agents or targeted chelation at time of highest IO risk. This review discusses the pathophysiology of IO in hematologic disease, the evidence supporting and refuting its negative impact on HCT outcomes, as well as current and future therapies.

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.

What is known about deferasirox chelation therapy in pediatric HSCT recipients: two case reports of metabolic acidosis

To date, in pediatric field, various hematological malignancies are increasingly treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). Iron overload and systemic siderosis often occur in this particular cohort of patients and are associated with poor prognosis. We describe herein the case of two allo-HSCT patients, on treatment with deferasirox; they showed histopathological elements compatible with venoocclusive disease or vanishing bile duct syndrome in ductopenic evolution before deferasirox started. The first patient developed drug-induced liver damage with metabolic acidosis and the second one a liver impairment with Fanconi syndrome. After withdrawing deferasirox treatment, both patients showed improvement. Measurements of drug plasma concentrations were performed by HPLC assay. The reduction and consequent disappearance of symptoms after the suspension of deferasirox substantiate its role in inducing hepatic damage, probably enabling the diagnosis of drug-induced liver damage. But the difficulties in diagnosing drug-related toxicity must be underlined, especially in compromised subjects. For these reasons, in patients requiring iron-chelating therapy, close and careful drug therapeutic monitoring is strongly recommended.

Deferasirox for the treatment of iron overload after allogeneic hematopoietic cell transplantation: multicenter phase I study (KSGCT1302)

The aim of this study was to assess the safety and optimal dose of deferasirox for the treatment of iron overload after allogeneic hematopoietic cell transplantation (HCT). The primary endpoint was the maximum tolerated dose of deferasirox that was determined by the intrapatient dose escalation methods. A total of 16 patients with post-HCT iron overload were enrolled in the study. After excluding one case of early relapse, 15 remained evaluable. Their median age was 42 years (range 22-68). Median time from HCT to deferasirox administration was 9 months (range 6-84). Deferasirox was started at a dose of 5 mg/kg, and the dose was increased to 7.5 and 10 mg/kg every 4 weeks unless there were no grade ≥ 2 of adverse events. Achievement rates of planned medication were 80% in 5 mg/kg (12 of 15), 73% in 7.5 mg/kg (11 of 15), and 60% in 10 mg/kg (9 of 15), respectively. The reasons for discontinuation of the drug were grade 2 of adverse events (n = 4), late relapse (n = 1), and self-cessation (n = 1). None of the patients developed grade ≥ 3 of adverse events or exacerbation of GVHD. Among 11 evaluable cases, mean value of ferritin decreased from 1560 ng/ml pre-treatment to 1285 ng/ml post-treatment. These data suggested that 10 mg/kg of deferasirox may be maximum tolerated dose when given after HCT. Our dose escalating method of deferasirox is useful to identify the optimal dosage of the drug in each patient.

TRIAL REGISTRATION

UMIN000011251.

Safety and tolerability of deferasirox in pediatric hematopoietic stem cell transplant recipients: one facility's five years' experience of chelation treatment

42 pediatric patients with iron overload, who underwent liver biopsy and DFX treatment after hematopoietic stem cell transplantation were included in the study group. The patients were divided into two groups diversified according to deferasirox trough plasma concentrations (DFX C_trough) with cut-off equal to10 mcg/mL. The average dose of DFX was 25.9 mg/kg in the DFX C_trough < 10 mcg/mL group versus 19.2 mg/kg in the DFX C_trough > 10 mcg/mL group (p=0,0003). The mean duration of DFX treatment was 135.7 days in the DFX C_trough < 10 mcg/mL group versus 41.8 days in the DFX C_trough > 10 mcg/mL group (p<0.0001). The mean tissue iron concentration in the DFX C_trough < 10 mcg/mL group was 261.9 μmol/g versus 133.4 μmol/g in the DFX C_trough > 10 mcg/mL group (p < 0.0001). 21 patients (100%) in the DFX C_trough > 10 mcg/mL group had ductopenia which was complete in 47.6% of them and severe in 52.4%. All patients with particularly high C_trough (> 25 mcg/mL) were found to have total ductopenia. 90.5% of all deferasirox-related adverse events and 100% of major adverse events occurred in the DFX C_trough > 10 mcg/mL group. In the DFX C_trough < 10 mcg/mL group only one patient interrupted chelation therapy versus 16 (84.2%) patients in the DFX C_trough > 10 mcg/mL group. We would recommend a close monitoring in pediatric hematopoietic transplant recipients subjected to deferasirox-based therapy because we have observed a high incidence of adverse events and discontinuation of chelation treatment.

Current Review of Iron Overload and Related Complications in Hematopoietic Stem Cell Transplantation

Iron overload is an adverse prognostic factor for patients undergoing hematopoietic stem cell transplantation (HSCT). In the HSCT setting, pretransplant and early posttransplant ferritin and transferrin saturation were found to be highly elevated due to high transfusion requirements. In addition to that, post-HSCT iron overload was shown to be related to infections, hepatic sinusoidal obstruction syndrome, mucositis, liver dysfunction, and acute graft-versus-host disease. Hyperferritinemia causes decreased survival rates in both pre- and posttransplant settings. Serum ferritin levels, magnetic resonance imaging, and liver biopsy are diagnostic tools for iron overload. Organ dysfunction due to iron overload may cause high mortality rates and therefore sufficient iron chelation therapy is recommended in this setting. In this review the management of iron overload in adult HSCT is discussed.

One-year results from a prospective randomized trial comparing phlebotomy with deferasirox for the treatment of iron overload in pediatric patients with thalassemia major following curative stem cell transplantation

BACKGROUND

Iron overload is well documented in patients with β-thalassemia major, and patients who have undergone hematopoietic stem cell transplantation (HSCT) remain at risk as a result of pre- and immediate post-HSCT transfusions.

PROCEDURE

This is a prospective, randomized, 1-year clinical trial that compares the efficacy and safety of the once-daily oral iron chelator deferasirox versus phlebotomy for the treatment of iron overload in children with β-thalassemia major following HSCT.

RESULTS

Patients (aged 12.4 years) received deferasirox (n = 12, 10 mg/kg/day starting dose) or phlebotomy (n = 14, 6 ml/kg/2 weeks) for 1 year. In two and five patients, deferasirox dose was increased to 15 and 20 mg/kg/day, respectively. Magnetic resonance imaging (MRI)-assessed liver iron concentration (LIC) decreased with deferasirox (mean 12.5 ± 10.1 to 8.5 ± 9.3 mg Fe/g dry weight [dw]; P = 0.0005 vs. baseline) and phlebotomy (10.2 ± 6.8 to 8.3 ± 9.2 mg Fe/g dw; P = 0.05). LIC reductions were greater with deferasirox than with phlebotomy for patients with baseline serum ferritin 1,000 ng/ml or higher (-8.1 ± 1.5 vs. -3.5 ± 5.7 mg Fe/g dw; P = 0.048). Serum ferritin and non-transferrin-bound iron also decreased significantly. In two patients with severe cardiac siderosis, a clinically relevant improvement in myocardial T2* was seen, following phlebotomy and deferasirox therapy (n = 1 each). Adverse effects with deferasirox were skin rash, gastrointestinal upset, and increased liver function tests (all n = 1), while those for phlebotomy were difficulty with venous access (n = 4) and distress during procedure (n = 1). Parents of 13/14 children receiving phlebotomy wished to switch to deferasirox, with 1/14 being satisfied with phlebotomy.

CONCLUSIONS

Deferasirox treatment or phlebotomy reduces iron burden in pediatric patients with β- thalassemia major post-HSCT, with a manageable safety profile.

[Assessment and management of post-transplant iron overload: Guidelines of the Francophone Society of Marrow Transplantation and Cellular Therapy (SFGM-TC)]

To harmonize clinical practice in hematopoietic stem cell transplantation, the Francophone Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the sixth annual series of workshops which brought together practitioners from all member centers and took place in September 2015 in Lille. The main aim of this session was to describe the impact, evaluation and treatment of post-transplant iron overload.

Prognostic pre-transplant factors in myelodysplastic syndromes primarily treated by high dose allogeneic hematopoietic stem cell transplantation: a retrospective study of the MDS subcommittee of the CMWP of the EBMT

Many pre-transplant factors are known to influence the outcome of allogeneic stem cell transplantation (SCT) treatment in myelodysplastic syndromes (MDS). However, patient cohorts are often heterogeneous by disease stage and treatment modalities, which complicates interpretation of the results. This study aimed to obtain a homogeneous patient cohort by including only de novo MDS patients who received upfront allogeneic SCT after standard high dose myelo-ablative conditioning. The effect of pre-transplant factors such as age, disease stage, transfusions, iron parameters and comorbidity on overall survival (OS), non-relapse mortality (NRM), and relapse incidence (RI) was evaluated in 201 patients. In this cohort, characterized by low comorbidity and a short interval between diagnosis and transplantation, NRM was the most determinant factor for survival after SCT (47 % after 2-year follow-up). WHO classification and transfusion burden were the only modalities with a significant impact on overall survival after SCT. Estimated hazard ratios (HR) showed a strongly increased risk of death, NRM and RI, in patients with a high transfusion-burden (HR 1.99; P = 0.006, HR of 1.89; P = 0.03 and HR 2.67; P = 0.03). The HR's for ferritin level and comorbidity were not significantly increased.

Management of iron overload before, during, and after hematopoietic stem cell transplantation for thalassemia major

Solid evidence has established the negative impact of high iron burden and related tissue damage on the outcome of hemopoietic stem cell transplantation for thalassemia major. Recent improvements in our knowledge of iron metabolism have been focused on elevated non-transferrin-bound iron and labile plasma iron levels in the peritransplantation period as potential contributors to tissue toxicity and subsequent adverse transplant outcome. As mouse models have shown, iron overload can injure bone marrow hematopoiesis by increasing reactive oxygen species. The Pesaro experience, conducted in the deferoxamine-only era, clearly defined three iron-related factors (liver fibrosis, hepatomegaly, and quality of lifelong chelation) as significantly affecting transplant outcome. The detrimental effect of iron has only been clarified in recent years. Active interventional strategies are ongoing. Although successful hematopoietic stem cell transplantation clinically resolves the thalassemia marrow defect, patients still remain carriers of iron overload and of all the clinical complications acquired during prior years of transfusion therapy. Therefore, adequate "iron diagnosis" and management is mandatory after hemopoietic stem cell transplantation. In transplanted thalassemia patients, body iron should be returned to within the normal range. Phlebotomy is the gold standard to reduce iron burden; though deferoxamine is a proven, acceptable alternative, clinical investigations on deferasirox are ongoing.

Initial serum ferritin predicts number of therapeutic phlebotomies to iron depletion in secondary iron overload

BACKGROUND

Therapeutic phlebotomy is increasingly used in patients with transfusional siderosis to mitigate organ injury associated with iron overload (IO). Laboratory response variables and therapy duration are not well characterized in such patients.

STUDY DESIGN AND METHODS

We retrospectively evaluated 99 consecutive patients undergoing therapeutic phlebotomy for either transfusional IO (TIO, n = 88; 76% had undergone hematopoietic transplantation) or nontransfusional indications (hyperferritinemia or erythrocytosis; n = 11). Complete blood cell count, serum ferritin (SF), transferrin saturation, and transaminases were measured serially. Phlebotomy goal was an SF level of less than 300 μg/L.

RESULTS

Mean SF levels before phlebotomy among TIO and nontransfusional subjects were 3093 and 396 μg/L, respectively. Transfusion burden in the TIO group was 94 ± 108 (mean ± SD) RBC units; approximately half completed therapy with 24 ± 23 phlebotomies (range, 1-103). One-third were lost to follow-up. Overall, 15% had mild adverse effects, including headache, nausea, and dizziness, mainly during first phlebotomy. Prior transfusion burden correlated poorly with initial ferritin and total number of phlebotomies to target in the TIO group. However, number of phlebotomies to target was strongly correlated with initial SF (R(2) = 0.8; p < 0.0001) in both TIO and nontransfusional groups. ALT decreased significantly with serial phlebotomy in all groups (mean initial and final values, 61 and 39 U/L; p = 0.03).

CONCLUSIONS

Initial SF but not transfusion burden predicted number of phlebotomies to target in patients with TIO. Despite good treatment tolerance, significant losses to follow-up were noted. Providing patients with an estimated phlebotomy number and follow-up duration, and thus a finite endpoint, may improve compliance. Hepatic function improved with iron offloading.

Iron overload in allogeneic hematopoietic cell transplantation outcome: a meta-analysis

An elevated ferritin level before allogeneic hematopoietic cell transplantation (HCT) is an adverse prognostic factor for overall survival (OS) and nonrelapse mortality. Because ferritin is an imperfect surrogate of iron stores, the prognostic role of iron overload remains unclear. We conducted a patient-level meta-analysis of 4 studies that used magnetic resonance imaging to estimate pre-HCT liver iron content (LIC). An elevated LIC was not associated with a significant increase in mortality: the hazard ratio (HR) for mortality associated with LIC > 7 mg/g dry weight (primary endpoint) was 1.4 (P = .18). In contrast, ferritin >1000 ng/mL was a significant prognostic factor (HR for mortality, 1.7; P = .036). There was, however, no significant association between ferritin > 2500 and mortality. This meta-analysis suggests that iron overload, as assessed by LIC, is not a strong prognostic factor for OS in a general adult HCT population. Our data also suggest that ferritin is an inadequate surrogate for iron overload in HCT.

The oral iron chelator deferasirox might improve survival in allogeneic hematopoietic cell transplant (alloHSCT) recipients with transfusional iron overload

INTRODUCTION

Iron overload (IO) has been shown to be an important cause of mortality and morbidity in patients who underwent allogeneic hematopoietic stem cell transplantation (alloHSCT). This study aimed to evaluate the possible effect of oral iron-chelation treatment (deferasirox) on survival in alloHSCT recipients in the posttransplant period.

MATERIALS AND METHODS

A total of 80 alloHSCT recipients with IO were analyzed, retrospectively. Pretransplant and posttransplant data were obtained from the patients' files. Patients were divided into two groups. Group 1; patients who did not receive any chelator treatment due to side effects or compliance problems. These patients were treated by phlebotomy. Group 2 consisted of patients who received deferasirox treatment.

RESULTS

The median treatment duration with deferasirox was 122 days (min-max:91-225). The iron chelating treatment significantly reduced serum ferritin levels administered at a dosage of 20-30 mg/kg/day (p<0.001). The median OS in Group 1 was found 16.0 (min-max:1.0-63.0) months and 25.0 (min-max:3.0-72.0) months in Group 2. In univariate and multivariate analysis, patients in Group 1 showed poorer OS compared to those in Group 2 with an increase in risk of death (HR:3.22, min-max:1.67-6.23, p=0.001 and HR:3.51,, min-max:1.75-6.99, p<0.001; respectively). The median DFS in Group 1 was found 11.0 (min-max:3.0-24.0) months and 22.0 (min-max:8.0-43.0) months in Group 2. The difference was found statistically significant (p=0.023). The other factors that we found significant difference in multivariate analysis between groups were; presence of acute GVHD (patients with aGVHD had increased risk of death compared to patients without aGVHD (HR:2.49, min-max: 1.32-4.69, p=0.005), chronic GVHD (HR:2.57, min-max:1.23-5.41, p=0.013), median interval to tx (HR: 2.23, min-max:1.17-4.26, p=0.015) and HLA match (HR:3.01, min-max:1.35-6.73, p=0.007) CONCLUSION: Oral deferasirox (Exjade) treatment may improve survival in patients with iron overload who underwent alloHSCT.

Safety and efficacy of deferasirox in the management of transfusion-dependent patients with myelodysplastic syndrome and aplastic anaemia: a perspective review

Deferasirox is an orally administered, once-daily iron chelator with a generally good safety and efficacy profile. Reported adverse events in the older myelodysplastic population are somewhat different to the more intensively investigated and younger thalassaemic population. Renal impairment is the most concerning adverse event, but this is reversible if identified and the drug is withdrawn early. Gastrointestinal effects, particularly diarrhoea, can be troublesome for older patients, but can be minimized with tailored therapy. Negative iron balance can be achieved in most patients with a median dose of 20 mg/kg/day, and doses up to 40 mg/kg are possible in patients with severe iron overload, who are at risk of cardiac decompensation.

The management of iron overload in allogeneic hematopoietic stem cell transplant (alloHSCT) recipients: where do we stand?

Iron overload (IO), primarily related to multiple red blood cell transfusions, is a relatively common complication in hematopoietic stem cell transplant (HSCT) recipients. Elevated pretransplant ferritin levels have been reported to increase the risk of non-relapse mortality following HSCT and might influence the risk of acute and chronic graft versus host disease. IO has been shown to be an important cause of mortality and morbidity in patients who have undergone alloHSCT (Armand et al., Blood 109:4586-4588, 2007; Kim et al., Acta Haematol 120:182-189, 2008; Kataoka et al., Biol Blood Marrow Transplant 15:195-204, 2009). We know that excessive iron accumulation results in tissue damage and organ failure, mainly as a result of the generation of free radicals that cause oxidative damage and organ dysfunction (e.g., hepatotoxicity, cardiotoxicity, and endocrine dysfunction) (Altes et al., Bone Marrow Transplantation 29: 987-989, 2002; Papanikolaou et al., Toxicol Appl Pharmac 202:199-211, 2005). In the last decade, efforts have been directed toward identifying alternative treatment for IO in alloHSCT recipients to maintain improved transplant outcomes.