Hypoxic Red Blood Cells in Sickle Cell Anemia

Inclusion Criteria: 1. Male or female at least 7 years of age; 2. Are able to provide informed consent, and assent as applicable, to participate in the study; 3. Diagnosis of Sickle Cell Anemia (SCA) (HbSS, HbSβ0 thalassemia) with participation in a chronic transfusion program and have undergone regular transfusions during at least 6 months prior to Screening; 4. Have had an average interval of at least 14 days between RBC transfusions over the past 6 months; 5. If on iron chelation therapy, have been on a stable dose for ≥3 months prior to screening; Exclusion Criteria: 1. Are not exclusively transfused at the site; 2. Have a diagnosis of HbSC disease, HbSβ+ thalassemia or another SCD variant (excluding HbSS and HbSβ0 thalassemia) 3. Are routinely transfused with washed, packed RBC units; 4. Have received hemoglobin inducers (e.g. erythropoietin) in the 30 days prior to Screening; 5. Are currently being evaluated for gene therapy; 6. Have any clinically significant pulmonary, cardiovascular, endocrine, hepatic, gastrointestinal, renal, infectious, immunological (including significant allo- or auto-immunization) disease, considered not adequately controlled prior to the study; 7. Are a female of child-bearing potential who is pregnant or planning to become pregnant in the next 14 months; 8. Have a history of allo-immunization that cannot be managed by the local blood bank; 9. Patients who, in the opinion of the Investigator, would not be able or willing to comply with the protocol; 10. Is a ward of the state, prisoner, or transient