The National Heart, Lung, and Blood Institute (NHLBI) has stopped a clinical trial evaluating a new approach to reduce the risk of recurrent stroke in children with sickle cell anemia and iron overload because of evidence that the new treatment was unlikely to prove better than the existing treatment.
The 26-site trial, Stroke With Transfusions Changing to Hydroxyurea, or SWiTCH, studied 133 participants between the ages of 5 and 18 who had already experienced a stroke. All had been receiving the standard treatment of blood transfusions for at least 18 months and high levels of iron before entering the study. Without further preventive measures, these children were at high risk of another stroke as well as life-threatening conditions due to iron overload.
The study tested whether the drug hydroxyurea, known to prevent complications of sickle cell disease in adults, was as effective as transfusions, the standard therapy, in reducing the risk of recurrent strokes. Hydroxyurea is the only FDA-approved drug for treating sickle cell anemia.
The study also compared two approaches to remove excess iron, a consequence of regular blood transfusions. Participants who continued to receive transfusion therapy were given the standard oral iron-removal drug deferasirox, and participants who were switched to hydroxyurea underwent regular phlebotomy (blood removal) to eliminate excess iron that had accumulated from their earlier transfusions.
Phlebotomy did not reduce liver iron better than deferasirox therapy. Analysis of the available data indicated that continuing the trial was unlikely to show that phlebotomy would provide a greater benefit than deferasirox to control iron accumulation. Without the ability to provide benefits for the management of liver iron, the potential risks of continuing study treatments were no longer warranted.
"Protecting our participants is an important factor in determining whether to stop a tri
|Contact: NHLBI Communications Office|
NIH/National Heart, Lung and Blood Institute