|Margaret Tonda, PharmD|
11 United States sites
4 United Kingdom sites
2 Lebanon sites
9 to 17 Years
1. Male or female participants with homozygous hemoglobin SS (HbSS) or hemoglobin S beta0
thalassemia (HbS β0thal)
1. Part A – 6 to 17 years of age
2. Part B – 12 to 17 years of age
3. Part C – 4 to 17 years of age
4. Part D – 9 months to <4 years of age 3. Hydroxyurea (HU) therapy: - Parts A, B, and C: A participant taking hydroxyurea (HU) may be enrolled if the dose has been stable for at least 3 months with no anticipated need for dose adjustment during the study and no sign of hematological toxicity. - Part D: A participant taking HU may be enrolled if the dose has been stable for at least 1 month. Titration to the maximum tolerated dose (MTD) is allowed during the study. 4. Hemoglobin (HB): 1. Part A - No restriction 2. Parts B, C, & D - Hb ≤ 10.5 g/dL 10. For Part C only: Participants 12 to 17 years of age must have a TCD velocity of ≥ 140 cm/sec measured anytime during screening.
1. Any one of the following requiring medical attention within 14 days of signing the
Informed Consent Form (ICF):
– Vaso-occlusive crisis (VOC)
– Acute chest syndrome (ACS)
– Splenic sequestration crisis
2. Requires chronic transfusion therapy
3. History of stroke or meeting criteria for primary stroke prophylaxis (history of two
TCD measurements ≥ 200 cm/sec by non-imaging TCD or ≥185 cm/sec by TCDi).
4. Transfusion within 30 days prior to signing the ICF
Exclusion Criteria for Part D Only:
16. Body weight <5 kg for 1 month prior to the screening visit and at the screening visit.