Monitoring long‐term efficacy of iron chelation therapy by deferiprone and desferrioxamine in patients with β‐thalassaemia major: application of SQUID biomagnetic liver susceptometry

Abstract

Summary. In this non‐randomized prospective study, liver and spleen iron concentrations were monitored annually over a 4‐year period by non‐invasive Superconducting Quantum Interference Device biomagnetometry in 54 β‐thalassaemia major patients (age, 7–22 years) receiving treatment with deferiprone (75 mg/kg/d). Median liver iron concentrations increased significantly from 1456 to 2029 and 2449 µg/gliver at baseline, after 2·0 and 3·2 years respectively. Another group of 51 thalassaemic patients (aged 4–34 years) who received desferrioxamine s.c. for 1·9 years increased their liver iron concentration from 1076 to 1260 µg/gliver. Taking into account the increase of the daily iron input from transfusions of 3·6 mg/d, caused by weight gain in 67% of the patients treated with deferiprone, a larger total body iron elimination rate was achieved after 2 years than at baseline. A negative ferritin change was observed in 51% of the patients. In 15 non‐splenectomized patients, liver iron significantly increased from 1260 to 1937 µg/gliver (P < 0·01), but serum ferritin remained stable at 2100 µg/l, as did the spleen iron concentration at 1200 µg/gspleen. A two‐compartment model may predict an average chelation efficacy for desferrioxamine and deferiprone, with a saturation effect of the latter, for a certain chelation and transfusion regimen by a single liver iron quantification.

Deferiprone (GPO‐L‐ONE®) monotherapy reduces iron overload in transfusion‐dependent thalassemias: 1‐year results from a multicenter prospective, single arm, open label, dose escalating phase III pediatric study (GPO‐L‐ONE; A001) from Thailand

“…These groups of patients were inadequately treated or chelation naive with very high levels of baseline serum ferritin and high iron intake from blood transfusion [11,[36][37][38][39][40][41]. Furthermore our findings that SF values were more likely to decrease in those patients who began with the highest SF values and lower iron intake from lower transfusion rate (<0.25 mg/kg/day in our study) are consistent with previous individual studies [42][43][44] and review of trends from several studies [38]. Also in the view of without a strong evidence to suggest that deferiprone has superior efficacy than desferoxamine, together with its associated adverse effects, some can be fatal, deferiprone remains the second line therapy for thalassemia major patients whose desferoxamine is inadequate or contraindicated as reviewed [45,46] and documented in all clinical practice guidelines around the world [47][48][49] including the latest registration filed by the US-FDA [50].…”

Safety and efficacy of pegylated interferon -2a and ribavirin for the treatment of hepatitis C in patients with thalassemia

“…As total body iron excretion cannot be measured long-term, the molar efficacy of DFO was calculated from the daily iron input from blood transfusions (FeTx), the chelator dose rate (D), and the difference in total body iron stores (TBI) as defined by equation, 1,13 with TBI calculated from dry weight LIC and body weight at baseline and 48 weeks (time interval ∆t). …”

Magnetic Resonance Imaging Assessment of Excess Iron in Thalassemia, Sickle Cell Disease and Other Iron Overload Diseases

“…It is also disliked by patients, making it difficult to perform serially at reasonable intervals. Although the superconducting quantum interference device (SQUID) has been used as a non invasive alternative to liver iron estimation, there are only four functioning devices in the world, critically limiting this technique (14).…”