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.

Health-related quality of life in transfusion-dependent patients with myelodysplastic syndromes: a prospective study to assess the impact of iron chelation therapy.

OBJECTIVE: The primary objective of this study was to evaluate the health-related quality of life (HRQOL) in lower-risk, transfusion-dependent patients with myelodysplastic syndromes (MDS) treated with deferasirox. A secondary objective was to investigate the relationship between HRQOL, serum ferritin levels and transfusion dependency. PATIENTS AND METHODS: This was a prospective multicentre study enrolling 159 patients, of whom 152 received at least one dose of deferasirox. HRQOL was assessed with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) at baseline and then at 3, 6, 9 and 12 months. Primary analysis was performed estimating mean HRQOL scores over time by a linear mixed model on selected scales. RESULTS: The median age of treated patients was 72 years (range 24-87 years). No statistically significant changes over time were found in mean scores for global health status/quality of life (p=0.564), physical functioning (p=0.409) and fatigue (p=0.471) scales. Also, no significant changes were found for constipation (p=0.292), diarrhoea (p=0.815) and nausea and vomiting (p=0.643). Serum ferritin levels were not associated with HRQOL outcomes. A higher patient-reported baseline pain severity was an independent predictive factor of an earlier achievement of transfusion independence with a HR of 1.032 (99% CI 1.004 to 1.060; p=0.003). CONCLUSIONS: HRQOL of transfusion-dependent patients with MDS receiving deferasirox therapy remains stable over time. HRQOL assessment might also provide important predictive information on treatment outcomes. TRIAL REGISTRATION NUMBER: NCT00469560.

Deferasirox for transfusion-dependent patients with myelodysplastic syndromes: safety, efficacy, and beyond (GIMEMA MDS0306 Trial).

BACKGROUND: In the absence of randomized, controlled trial data to support iron chelation therapy in transfusion-dependent patients with myelodysplastic syndromes (MDS), continued evidence from large prospective clinical trials evaluating the efficacy and safety of iron chelation therapy in this patient population is warranted. METHODS: The safety and efficacy of deferasirox was examined in a prospective, open-label, single-arm, multicenter trial of transfusion-dependent patients with International Prognostic Scoring System low- or intermediate-1-risk MDS and evidence of transfusion-related iron overload. The effects of deferasirox therapy on hematological response and disease progression were also examined. RESULTS: Of 159 participants enrolled from 37 Italian centers, 152 received ≥1 dose of deferasirox (initiated at 10-20 mg/kg/day and titrated as appropriate), and 68 completed the study. Of 84 patients who discontinued deferasirox therapy, 22 died during the trial, and 28 withdrew due to an adverse event (AE). Fourteen treatment-related grade 3 AEs occurred in 11 patients, whereas no grade 4 or 5 drug-related AEs were reported. Significant risks for dropout were a higher serum ferritin level at baseline, a higher MDS-Specific Comorbidity Index, and a shorter diagnosis-enrollment interval. Median serum ferritin level fell from 1966 ng/mL to 1475 ng/mL (P < 0.0001). The cumulative incidence of transfusion independence, adjusted for death and disease progression, was 2.6%, 12.3%, and 15.5% after 6, 9, and 12 months, respectively. CONCLUSIONS: Deferasirox therapy in transfusion-dependent patients with MDS was moderately well tolerated and effectively lowered serum ferritin levels. Positive hematological responses were observed, and a subset of patients achieved transfusion independence.

Hematological improvement during iron-chelation therapy in myelodysplastic syndromes: the experience of the "Rete Ematologica Lombarda".

To analyze the unpredicted event of hematological improvement (HI) during iron-chelation therapy (ICT), we reviewed a series of 53 myelodysplastic patients with transfusion dependency in a retrospective study involving 8 centers afferent to the "Rete Ematologica Lombarda". According to the IWG response criteria published in the year 2000, we observed erythroid responses in 19 patients (35.1%), 5 major (9.2%) and 14 minor (25.9%). In the assessable patients, platelet response was 8/13 (61%) and neutrophil response was 13/17 (76.4%). Only in patients with erythroid improvement, multilineage responses were observed. Apparently, patients with greater erythropoiesis dysfunction may take more advantage.