Long Term Comparative Studies in Thalassemia Patients Treated with Deferoxamine or a Deferoxamine/Deferiprone Combination. Identification of Effective Chelation Therapy Protocols

Abstract

For the past 2–6 years, two groups of thalassemia patients, one of 16 patients on deferoxamine (DFO) monotherapy (35–80 mg/kg, 2–5 days/week) and the other group comprising 19 patients on a deferiprone (L1) and DFO combination therapy (L1 75–100 mg/kg/day and DFO 30–60 mg/kg, 1–5 days/week), have been studied and compared before and after the introduction of the combination therapy. The patients on the combination therapy were mainly those not complying or experiencing toxicity with DFO. The effects of chelation therapy on iron load was monitored using regular serum ferritin measurements and also magnetic resonance imaging (MRI) T2* relaxation time measurements at the end of the study. In both groups, cardiac MRI T2* levels were within the normal range (>19 ms) in more than 75% of the patients. There was a substantial improvement in serum ferritin levels and normalization of the MRI T2* levels of the liver in many cases treated with the combination therapy at effective doses by comparison to the DFO group, where the serum ferritin and MRI T2* levels were largely unchanged. It would appear that the major overall determining factor in the rapid clearance of excess iron in thalassemia patients and the maintenance of normal iron stores is the selection and implementation of effective chelation dose protocols. The International Committee on Chelation (ICOC) combination protocol L1 (80–110 mg/kg/day)/DFO (40–60 mg/kg at least 3 days per week) and to a lesser extent, DFO monotherapy at about 50 mg/kg/day, 5 days/week, appears to achieve this goal.