Pharmacological and clinical evaluation of deferasirox formulations for treatment tailoring.

Deferasirox (DFX) is the newest among three different chelators available to treat iron overload in iron-loading anaemias, firstly released as Dispersible Tablets (DT) and more recently replaced by Film-Coated Tablets (FCT). In this retrospective observational study, pharmacokinetics, pharmacodynamics, and safety features of DFX treatment were analyzed in 74 patients that took both formulations subsequently under clinical practice conditions. Bioavailability of DFX FCT compared to DT resulted higher than expected [Cmax: 99.5 (FCT) and 69.7 (DT) µMol/L; AUC: 1278 (FCT) and 846 (DT), P < 0.0001]. DFX FCT was also superior in scalability among doses. After one year of treatment for each formulation, no differences were observed between the treatments in the overall iron overload levels; however, DFX FCT but not DT showed a significant dose-response correlation [Spearman r (dose-serum ferritin variation): - 0.54, P < 0.0001]. Despite being administered at different dosages, the long-term safety profile was not different between formulations: a significant increase in renal impairment risk was observed for both treatments and it was reversible under strict monitoring (P < 0.002). Altogether, these data constitute a comprehensive comparison of DFX formulations in thalassaemia and other iron-loading anaemias, confirming the effectiveness and safety characteristics of DFX and its applicability for treatment tailoring.

Safety and efficacy of deferasirox in patients with transfusion-dependent thalassemia: A 4-year single-center experience.

This study was organized to determine the efficacy and safety of deferasirox (DFX) in reducing the SF of patients with transfusion-dependent thalassemia (TDT). This is a retrospective, descriptive study of 101 transfusion- dependent patients with thalassemia major who were followed for 48 months. Twenty-nine patients who used an alternative chelator either alone or combined, who were not compliant to the treatment, changed the drug due to adverse reactions, and had multiple transfusions and did not complete 4 years of DFX use were excluded. A total 72 out of 101 patients completed the study. SF decreases were noted for the 6-12 and >18-year age groups, from a median of 1532 ng/mL to 1190 ng/mL, and from 1386 ng/mL to 1165 ng/mL, respectively (p > 0.05). The proportion of patients with SF concentrations >2000 ng/mL is decreased (29% at baseline decreased to 15% at the end of the study) during the 48 months. The median SF of those who used <30 mg/kg/day (n = 38) increased from 767 ng/mL to 1006 ng/mL, whereas the >30 mg/kg/day (n = 34) group's SF concentrations decreased from a median of 1575 ng/mL to 1209 ng/mL (p = 0.029). The decrease of median SF values for Syrian patients was statistically significant (p = 0.043). Most common adverse events were gastric irritation symptoms (19.4%). The total DFX discontinuation ratio was calculated as 9.7%. Although dosages between 25-30 mg/kg/day are adequate to stabilize SF concentrations higher dosages are needed to achieve a statistically significant decrease.