The primary objective of this study is to determine the effect of mitapivat versus placebo on the need for transfusions in subjects with SCD.
Age ≥12 years.
Documented diagnosis of SCD (hemoglobin SS (HbSS), combined heterozygosity for hemoglobins S and C (HbSC), sickle cell hemoglobin (HbS)/β0-thalassemia, HbS/β+-thalassemia, or other sickle cell syndrome variants).
No more than 10 SCPCs in the 12 months before providing informed assent/consent.
At least 1 transfusion of packed RBCs in the 12 months before informed assent/consent.
Pregnant, breastfeeding, or parturient.
Receiving regularly scheduled RBC transfusion therapy (also termed chronic, prophylactic, or preventative transfusion); episodic transfusion in response to worsened anemia or vaso-occlusive crisis (VOC) is permitted. Additionally, a subject who requires episodic transfusion(s) may not have received a transfusion(s) within 60 days before providing informed assent/consent or during the Screening Period.
Hospitalized for an SCPC and/or other vaso-occlusive event within 14 days prior to providing informed assent/consent or during the Screening Period. A hospitalization is defined as an in-patient admission to a hospital that may or may not be preceded by an emergency room or outpatient clinic visit. A visit to an emergency room that does not result in an in-patient admission does not meet the definition of hospitalization.
Currently receiving treatment with a disease-modifying therapy for SCD (eg, voxelotor, crizanlizumab, L-glutamine), with the exception of hydroxyurea. The last dose of voxelotor, crizanlizumab, and L-glutamine must have been administered at least 90 days before randomization.