Limitations of serum ferritin to predict liver iron concentration responses to deferasirox therapy in patients with transfusion-dependent thalassaemia.

BACKGROUND: In transfusion-dependent anaemias, while absolute serum ferritin levels broadly correlate with liver iron concentration (LIC), relationships between trends in these variables are unclear. These relationships are important because serum ferritin changes are often used to adjust or switch chelation regimens when liver magnetic resonance imaging (MRI) is unavailable. OBJECTIVES AND METHODS: This post hoc analysis of the EPIC study compared serum ferritin and LIC in 317 patients with transfusion-dependent thalassaemia before and after 1 yr of deferasirox. RESULTS: Serum ferritin responses (decreases) occurred in 73% of patients, 80% of whom also have decreased LIC. However, 52% of patients without a serum ferritin response did decrease LIC and by >1 mg Fe/g dw (median 3.9) in 77% of cases. Absolute serum ferritin and LIC values correlated significantly only when serum ferritin was <4000 ng/mL (r = 0.59; P < 0.0001) and not at higher levels (≥4000 ng/mL; r = 0.19). Serum ferritin response was accompanied by decreased LIC in 89% and 70% of cases when serum ferritin was <4000 or ≥4000 ng/mL, respectively. CONCLUSIONS: As serum ferritin non-response was associated with LIC decrease in over half of patients, use of liver MRI may be particularly useful for differentiating true from apparent non-responders to deferasirox based on serum ferritin trends alone.

Utility of labile plasma iron and transferrin saturation in addition to serum ferritin as iron overload markers in different underlying anemias before and after deferasirox treatment.

OBJECTIVES: Plasma markers in addition to serum ferritin (SF) may be useful for the assessment of iron overload; however, predictive utility may differ depending on underlying, transfusion-dependent, anemias. METHODS: Data were collected before and after 1 year of deferasirox treatment (end of study; EOS) from the large, 1-year EPIC (Evaluation of Patients' Iron Chelation with Exjade(®) ) study. Trends were evaluated between liver iron concentration (LIC), transferrin saturation (TfSat), predose labile plasma iron (LPI) and their relationship to SF categories in 1530 patients: thalassemia major (TM; n = 1114), myelodysplastic syndromes (MDS, n = 336), and sickle-cell disease (SCD, n = 80). RESULTS: Baseline and EOS SF values showed a clear and similar relationship to LIC for all disease groups. TfSat also showed a relationship to SF, most clearly in patients with SCD, where TfSat was lowest in the lowest relative SF category. Unlike SF or LIC, TfSat did not decrease at EOS in any disease group. Baseline LPI was raised in TM and MDS, but not in patients with SCD, decreasing at EOS in both patient groups. After 1 year of chelation therapy, there was a significant trend for greater LPI reduction in patients with TM achieving LIC <7 mg Fe/g dw (P = 0.0137). CONCLUSIONS: Despite limitations, SF showed the clearest relationship, of the plasma markers evaluated, to LIC before and after 1 year of deferasirox in patients with TM, MDS, and SCD. In patients with TM, changes in LPI with chelation show a significant relationship to EOS LIC and may provide an additional indicator of chelation response (clinicaltrials.gov identifier: NCT00171821).

Hematologic responses in patients with aplastic anemia treated with deferasirox: a post hoc analysis from the EPIC study.

Reports are emerging of hematologic responses associated with iron chelation therapy; however, studies are limited in aplastic anemia patients. Deferasirox reduced iron overload in aplastic anemia patients enrolled in the EPIC (Evaluation of Patients' Iron Chelation with Exjade(®)) study (n=116). A post hoc analysis of hematologic responses was conducted on 72 patients with evaluable hematologic parameters (according to UK guideline criteria), 24 of whom received deferasirox without concomitant immunosuppressive treatment. Partial hematologic responses were observed in 11 of 24 (45.8%) patients; all became transfusion-independent. One patient had an additional platelet response and one patient had an additional platelet and hemoglobin response. Mean serum ferritin levels at end of study were significantly reduced in partial hematologic responders (n=11; -3948 ± 4998 ng/mL; baseline 6693 ± 7014 ng/mL; percentage change from baseline -45.7%; P=0.0029). In non-responders, the reduction in serum ferritin was less pronounced (n=13; -2021 ± 3242 ng/mL; baseline 4365 ± 3063 ng/mL; % change from baseline -27.6%; P=0.0171). Alongside reduction in iron overload, deferasirox may, therefore, improve hematologic parameters in a subset of aplastic anemia patients. Further investigation is required to elucidate the mechanisms involved.

Importance of optimal dosing ≥ 30 mg/kg/d during deferasirox treatment: 2.7-yr follow-up from the ESCALATOR study in patients with ß-thalassaemia.

Following 1-yr deferasirox therapy in the ESCALATOR study, 57% of previously chelated patients with ß-thalassaemia achieved treatment success (maintenance of or reduction in liver iron concentration (LIC) vs. baseline LIC). Seventy-eight per cent had dose increases at median of 26 wk, suggesting that 1-yr results may not have reflected full deferasirox efficacy. Extension data are presented here. Deferasirox starting dose was 20 mg/kg/d (increases to 30/40 mg/kg/d permitted in the core/extension, respectively). Efficacy was primarily assessed by absolute change in LIC and serum ferritin. Overall, 231 patients received deferasirox in the extension; 67.4% (P < 0.0001) achieved treatment success. By the end of the extension, 66.2% of patients were receiving doses ≥ 30 mg/kg/d. By the end of the 1-yr extension, mean LIC had decreased by 6.6 ± 9.4 mg Fe/g dw (baseline 19.6 ± 9.2; P < 0.001) and median serum ferritin by 929 ng/mL (baseline 3356; P < 0.0001). There was a concomitant improvement in liver function markers (P < 0.0001). Fewer drug-related adverse events were reported in extension than core study (23.8% vs. 44.3%). Doses ≥ 30 mg/kg/d were generally required because of high transfusional iron intake and high baseline serum ferritin levels, highlighting the importance of administering an adequate dose to achieve net negative iron balance.