Thalassaemia is a genetic disease in which there is a reduced ability to produce haemoglobin. Management by regular blood transfusions results in excess iron in the body. Removal of excess iron is vital to prevent damage to major organs. This is achieved through iron chelation therapy; one common iron chelator is deferiprone. Questions exist about whether deferiprone is as good at removing excess iron, and as safe as the most widely used iron chelator desferrioxamine (DFO).
Ten randomised controlled trials were identified that compared deferiprone with DFO for the treatment of transfusion-dependent thalassaemia. Removal of excess iron was assessed in a number of ways by these trials: measuring iron concentration in the blood and in the liver; measuring how well the heart functions; and measuring the amount of iron that is excreted in urine. However, there was little consistency in the amount of iron removed with either deferiprone or DFO; for some of these measures the amount of iron removed was greater with deferiprone, for other measures the amount of iron removed was greater with DFO. One of the reasons for this inconsistency is that there were many differences in how these measures were made and assessed in the included trials.
Adverse events were recorded in trials comparing deferiprone with DFO. The range of adverse events that occurred across all trials included nausea, joint pain, stomach upsets and low white blood cell count with deferiprone and pain or skin reactions at the injection site and joint pain with DFO. In one trial, adverse events were significantly more likely with deferiprone than DFO, the risk of experiencing an adverse event with deferiprone was twice that of the risk of experiencing an adverse event with DFO (risk ratio 2.24 (95% confidence interval 1.19 to 4.23)).
A limitation to this review is the difference in the ways outcomes were measured by the included trials. This makes it difficult to compare results between the different trials.
We have found no evidence to change current treatment recommendations, namely that deferiprone is indicated for treating iron overload in people with thalassaemia major when desferrioxamine is contraindicated or inadequate. There is a need for more research that considers how the removal of excess iron is measured by trials and what the results of these measurements mean to a person with transfusion-dependent thalassaemia.