TY - JOUR
T1 - Hydroxyurea pharmacokinetics in children with sickle cell anemia across different global populations
AU - Power-Hays, Alexandra
AU - McElhinney, Kathryn E.
AU - Williams, Thomas N.
AU - Mochamah, George
AU - Olupot-Olupot, Peter
AU - Paasi, George
AU - Reid, Marvin E.
AU - Rankine-Mullings, Angela E.
AU - Opoka, Robert O.
AU - John, Chandy C.
AU - McGann, Patrick T.
AU - Quinn, Charles T.
AU - Punt, Nieko C.
AU - Smart, Luke R.
AU - Stuber, Susan E.
AU - Latham, Teresa S.
AU - Vinks, Alexander A.
AU - Ware, Russell E.
N1 - Publisher Copyright:
© 2026 The American Society of Hematology
PY - 2026/1/27
Y1 - 2026/1/27
N2 - Hydroxyurea provides effective disease-modifying treatment for people with sickle cell anemia (SCA), especially when escalated to maximum tolerated dose (MTD), which has wide interpatient dosing variability due to pharmacokinetic (PK) differences. Whether hydroxyurea PK parameters differ among children with SCA in different global regions is unknown. We compared hydroxyurea PK parameters among children with SCA from 5 clinical trials: HUSTLE (United States), TREAT (United States), NOHARM (Uganda), REACH (Uganda and Kenya), and EXTEND (Jamaica). Key hydroxyurea PK parameters were determined using HdxSim, a validated hydroxyurea PK software program. The results were compared across regions by analysis of variance. PK profiles from 451 children with SCA (146 from the United States, 265 from Africa, and 40 from the Caribbean) were included. Children from Africa had slightly lower volumes of distribution, but absorption rate and clearance were similar across regions. The PK-recommended doses to achieve MTD were statistically different but clinically similar across the United States (26.6 ± 5.9 mg/kg per day), Africa (27.6 ± 6.5 mg/kg per day), and the Caribbean (25.2 ± 4.7 mg/kg per day) (P = .04). In multivariable regression, younger age and increased reticulocyte counts were associated with higher PK-recommended doses. Hydroxyurea PK parameters in children with SCA differ minimally across global populations, predicting clinically similar doses to achieve MTD. Individualized hydroxyurea dosing based on a PK-population model derived from US children with SCA can be used broadly to maximize the benefits of this critical medication in other global populations. These trials were registered at www.ClinicalTrials.gov as #NCT00305175 (HUSTLE), #NCT02286154 (TREAT), #NCT01976416 (NOHARM), #NCT01966731 (REACH), and #NCT02556099 (EXTEND).
AB - Hydroxyurea provides effective disease-modifying treatment for people with sickle cell anemia (SCA), especially when escalated to maximum tolerated dose (MTD), which has wide interpatient dosing variability due to pharmacokinetic (PK) differences. Whether hydroxyurea PK parameters differ among children with SCA in different global regions is unknown. We compared hydroxyurea PK parameters among children with SCA from 5 clinical trials: HUSTLE (United States), TREAT (United States), NOHARM (Uganda), REACH (Uganda and Kenya), and EXTEND (Jamaica). Key hydroxyurea PK parameters were determined using HdxSim, a validated hydroxyurea PK software program. The results were compared across regions by analysis of variance. PK profiles from 451 children with SCA (146 from the United States, 265 from Africa, and 40 from the Caribbean) were included. Children from Africa had slightly lower volumes of distribution, but absorption rate and clearance were similar across regions. The PK-recommended doses to achieve MTD were statistically different but clinically similar across the United States (26.6 ± 5.9 mg/kg per day), Africa (27.6 ± 6.5 mg/kg per day), and the Caribbean (25.2 ± 4.7 mg/kg per day) (P = .04). In multivariable regression, younger age and increased reticulocyte counts were associated with higher PK-recommended doses. Hydroxyurea PK parameters in children with SCA differ minimally across global populations, predicting clinically similar doses to achieve MTD. Individualized hydroxyurea dosing based on a PK-population model derived from US children with SCA can be used broadly to maximize the benefits of this critical medication in other global populations. These trials were registered at www.ClinicalTrials.gov as #NCT00305175 (HUSTLE), #NCT02286154 (TREAT), #NCT01976416 (NOHARM), #NCT01966731 (REACH), and #NCT02556099 (EXTEND).
UR - https://www.scopus.com/pages/publications/105027388875
U2 - 10.1182/bloodadvances.2025017254
DO - 10.1182/bloodadvances.2025017254
M3 - Article
C2 - 41026975
AN - SCOPUS:105027388875
SN - 2473-9529
VL - 10
SP - 418
EP - 427
JO - Blood advances
JF - Blood advances
IS - 2
ER -