A clinical trial designed to compare the safety and iron excretion properties of desferoxamine (DFO) and deferitrin (GT56-252), an experimental oral iron chelator.

Inclusion Criteria:

• Beta-thalassemia patients, 18 years of age or older, currently undergoing chronic blood transfusion therapy and iron chelation therapy who weigh more than 40 kg.
• No clinically significant findings on physical exam, medical history, or screening laboratories.
• Serum ferritin greater than 500 ng/mL, serum creatine creatinine within the normal range and platelet count greater than 100,000/mm3.
• Willing and able to discontinue DFO or L1 for the period of study.
• Woman of child-bearing potential must have a negative serum pregnancy test at screening and use a medically acceptable form of birth control during the study and for 1 month afterward. Male patients must also use barrier contraceptives during the study and for 1 month afterward.
• Have a level of understanding and willingness to cooperate with the confinement and all procedures. Able to provide voluntary signed/dated written informed consent.

Exclusion Criteria:

• Serious medical condition unrelated to Beta-Thalassemia.
• Participation in a previous investigational drug study within 30 days preceding screening.
• Patients with a known allergy to DFO that prevents chronic administration.