To compare the effect of mitapivat versus placebo on transfusion burden in subjects with alpha- or beta-transfusiondependent thalassemia (TDT) Transfusion reduction response (TRR), defined as a 50% reduction in transfused red blood cell (RBC) units with a reduction of greater that or equal to 2 units of transfused RBCs in any consecutive 12-week period through Week 48 compared with baseline - greater than or equal to 33 percent reduction in transfused RBC units from Week 13 through Week 48 compared with baseline (TRR3) - greater than or equal to 50 percent reduction in transfused RBC units in any consecutive 24-week period through Week 48 compared with baseline (TRR2) - greater than or equal to 50 percent reduction in transfused RBC units from Week 13 through Week 48 compared with baseline (TRR4) - Change from baseline in transfused RBC units from Week 13 through Week 48 - Transfusion independence, defined as transfusion-free for greater than or equal to 8 consecutive weeks through Week 48 - Change from baseline in iron, serum ferritin, total iron binding capacity, and transferrin saturation through Week 48 - Type, severity, and relationship of adverse events (AEs) and serious adverse events - Plasma or blood concentrations and pharmacokinetic parameters of mitapivat and pharmacodynamic parameters, including adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG)

You may be eligible for this study if you meet the following criteria:

• Conditions: Medical Research
• Age: 99 years or below
• Gender: All