Long-term safety and efficacy of deferasirox in young pediatric patients with transfusional hemosiderosis: Results from a 5­year observational study (ENTRUST)

Background: Children with red blood cell disorders may receive regular transfusions from an early age and consequently accumulate iron. Adequate iron chelation therapy can prevent organ damage and delayed growth/development. Deferasirox is indicated for treatment of pediatric patients with chronic iron overload due to transfusional hemosiderosis; however, fewer than 10% of patients in the registration studies were aged 2 to less than 6 years. Procedure: Deferasirox, a once-daily oral iron chelator, was evaluated in young pediatric patients with transfusional hemosiderosis during the observational 5-year ENTRUST study. Patients aged 2 to less than 6 years at enrollment received deferasirox according to local prescribing information, with the primary objective of evaluating safety, specifically renal and hepatic function. Serum ferritin was observed as a surrogate efficacy parameter. Results: In total, 267 patients (mean age 3.2 years) predominantly with β-thalassemia (n = 176, 65.9%) were enrolled. Mean ± standard deviation deferasirox dose was 25.8 ± 6.5 mg/kg per day over a median of 59.9 months. A total of 145 patients (54.3%) completed 5 years’ treatment. The proportion of patients with two or more consecutive postbaseline measurements (≥7 days apart) of serum creatinine higher than age-adjusted upper limit of normal (ULN) and alanine aminotransferase more than five times the ULN was 4.4% (95% confidence interval [CI]: 2.1–7.9) and 4.0% (95% CI: 1.8–7.4), respectively. Median serum ferritin decreased from 1,702 ng/ml at baseline to 1,127 ng/ml at 5 years. There were no new safety signals. Conclusions: Safety and efficacy of deferasirox in young pediatric patients in this long-term, observational study in everyday clinical practice were consistent with the known deferasirox profile.