Iron Balance Study of DFO and GT56-252 in Patients With Transfusional Iron Overload Secondary to Beta-Thalassemia

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.