RecruitingPhase 3Drug trialA Study to Investigate the Efficacy, Pharmacokinetics, and Safety of Mitapivat in Pediatric Participants With Transfusion-Dependent Alpha- or Beta-Thalassemia (α- or β-TDT)The primary objective of this study is to compare the effect of mitapivat versus placebo on transfusion burden in pediatric participants with α- or β-transfusion-dependent thalassemia.