Study to Evaluate the Effect of GBT440 on TCD in Pediatrics With Sickle Cell Disease

Exclusion Criteria

• •1. Body weight \< 10kg at the screening visit
• •2. Hospitalization for VOC or acute chest syndrome (ACS) within the 14 days prior to execution of informed consent/assent
• •3. More than 10 VOCs within the past 12 months that required hospitalization, emergency room, or clinic visit
• •4. Stroke resulting in focal neurological deficit; previous silent infarcts are permitted.
• •5. Known history or findings suggestive of significant cerebral vasculopathy
• •6. History of seizure disorder
• •7. Has been treated with erythropoietin or other hematopoietic growth factors within 28 days of signing informed consent/assent or if, in the opinion of the Investigator, there is an anticipated need for such agents during the study
• •8. RBC transfusion therapy (also termed chronic, prophylactic, or preventative transfusion) or has received an RBC transfusion or exchange transfusion for any reason within 90 days of signing the informed consent/assent