Association of Liver Iron Concentration Levels with Myocardial T2* Responses in Transfusion-Dependent Thalassemia Major Patients Treated with Deferasirox and Deferoxamine- Extension of Cordelia Study

Abstract

Background: Beta thalassemia major patients (pts) are at an increased risk of heart failure, due to the deposition of iron in the heart causing myocardial siderosis. Intensive long-term iron chelation therapy (ICT) is required to obtain a normal myocardial T2* (mT2* >20 ms). Previously published studies suggested that cardiac iron removal lags changes in liver iron, and liver iron concentration (LIC) may affect the rate of removal of cardiac iron (Porter et al, ASH 2013). The objective of these analyses was to evaluate the association of the severity of LIC levels with the change in mT2* responses in pts with myocardial siderosis when treated with deferasirox (DFX) and deferoxamine (DFO) for up to 24 months (mo) in the CORDELIA study. Due to the very low pt numbers in the DFO arm, the results for these pts are not presented here. Methods: The study design, inclusion, and exclusion criteria have been reported previously (Pennell et al, Am J Hematol. 2015). Pts were categorized into LIC Results: Of 197 pts, 160 (81.2%) completed 12 mo of treatment and 146 (74.1%) entered into the extension study whereas 103 pts continued on initially assigned treatment. Pts completing 24 mo of treatment included 65 (87.8%) of 74 pts (mean age 20.1±6.9 years, 59.5% male) on DFX and the results for these pts are presented as follows. Average actual doses (mg/kg/d) were 26.7±8.9, 31.5±7.4, 38.0±2.9 for LIC The LIC levels for pts categorized by LIC For pts with BL LIC The mT2* responses for pts categorized according to visit specific LIC levels (LIC Discussion: Overall, DFX treatment resulted in a substantial decrease in LIC and improved mT2*. These results suggest a greater difference in mT2* improvement and CIC reduction in pts who achieved lower LIC during treatment with DFX. This divergence was progressive with time, being maximal at Mo 24. Thus, a therapeutic response in LIC with DFX may be associated with a greater likelihood of improving mT2*. Pts with high LIC ≥15 may require an effective long-term treatment with higher doses of ICT to have an improvement in mT2*, suggesting that cardiac iron removal is likely to be slow in heavily iron overloaded pts. These results are consistent with the previous report which showed a significant decrease in LIC and increased mT2* responses at Mo 36 in pts who attained lower end-of-year LIC levels when treated with DFX (Porter et al, ASH 2013) and highlight the potential value of monitoring the liver and cardiac responses during ICT. To further understand the kinetics between liver and cardiac iron removal, prospective investigation is warranted. Disclosures Pennell:Novartis: Consultancy, Research Funding; Apotex: Consultancy, Research Funding. Porter:Celgene: Consultancy; Novartis: Consultancy, Honoraria, Research Funding; Shire: Consultancy, Honoraria. Piga:Acceleron: Research Funding; Cerus: Research Funding; Apopharma: Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding; Celgene Corporation: Honoraria. Han:Novartis: Employment. Vorog:Novartis: Employment. Aydinok:Cerus: Research Funding; Sideris: Research Funding; Novartis: Membership on an entity9s Board of Directors or advisory committees, Research Funding, Speakers Bureau.