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

Following 1-yr deferasirox therapy in the ESCALATOR study, 57% of previously chelated patients with β-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 26wk, suggesting that 1-yr results may not have reflected full deferasirox efficacy. Extension data are presented here. Deferasirox starting dose was 20mg/kg/d (increases to 30/40mg/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 ≥30mg/kg/d. By the end of the 1-yr extension, mean LIC had decreased by 6.6±9.4mg Fe/g dw (baseline 19.6±9.2; P<0.001) and median serum ferritin by 929ng/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 ≥30mg/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.