Adherence to Iron Chelation Therapy with Deferasirox Formulations among Patients with Sickle Cell Disease and β-thalassemia

Abstract

Background: Individuals with hemoglobinopathies experience complications that often require management with multiple transfusions. These chronic transfusions can lead to iron overload, which places them at increased risk of organ damage, malignancy, and even death. Deferasirox is the most common iron chelator used to treat iron overload due to its safety, efficacy, and oral administration. The first formulation of deferasirox, a dispersible tablet for oral suspension (DT) called Exjade®, was associated with adherence challenges due to complaints from poor taste and side effects such as abdominal discomfort. A new film-coated tablet formulation (FCT) called Jadenu® was subsequently developed to overcome these challenges.

Objective: The objective of this study was to compare adherence rates between formulations of deferasirox (DT versus FCT) and describe associations between adherence to chelation therapy and changes in hematological parameters among patients with SCD and β-thalassemia.

Methods: In this retrospective study of 20 children and adults with sickle cell disease (SCD) and β-thalassemia with iron overload, we compared adherence rates for deferasirox DT versus deferasirox FCT. We reviewed data from the electronic medical record and pharmacy expense reports between 2014 and 2018. We calculated the mean medication possession ratio (MPR) and analyzed the mean paired difference in MPR and ferritin levels using paired sample t-test.

Results: The overall mean MPR was 0.15 (0.25) for deferasirox DT and 0.44 (0.32) for deferasirox FCT. The mean paired difference in MPR when transitioning from deferasirox DT to deferasirox FCT was +0.29, p-value < 0.01 (95% CI: 0.19, 0.39). The mean paired difference in ferritin while on deferasirox DT compared to ferritin 6 months after transitioning to deferasirox FCT was -306 ng/mL p-value = 0.14 (95% CI: 719, 113).

Conclusion: There was significant improvement in adherence to iron chelation therapy when patients transitioned from deferasirox DT to deferasirox FCT.

Keywords: Deferasirox; Iron chelation therapy; Iron overload; Sickle cell disease; Thalassemia.