The treatment period started once the patient completed the core study and signed informed consent. It is continued for up to 4 years. Safety parameters were assessed every 4 weeks. Eye and Ear examinations were performed on a yearly basis. To further investigate the extent of iron overload, serum ferritin, iron, and transferrin were monitored every four weeks. The Program Safety Board monitored the safety of ICL670 during the study to evaluate and categorize any serious case reported in association with ICL670.