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BackgroundHydroxyurea is an effective treatment for sickle cell anemia, but few studies have been conducted in sub-Saharan Africa, where the burden is greatest. Coexisting conditions such as malnutrition and malaria may affect the feasibility, safety, and benefits of hydroxyurea in low-resource settings.MethodsWe enrolled children 1 to 10 years of age with sickle cell anemia in four sub-Saharan countries. Children received hydroxyurea at a dose of 15 to 20 mg per kilogram of body weight per day for 6 months, followed by dose escalation. The end points assessed feasibility (enrollment, retention, and adherence), safety (dose levels, toxic effects, and malaria), and benefits (laboratory variables, sickle cell-related events, transfusions, and survival).ResultsA total of 635 children were fully enrolled; 606 children completed screening and began receiving hydroxyurea at a mean (±SD) dose of 17.5±1.8 mg per kilogram per day. The retention rate was 94.2% at 3 years of treatment. Hydroxyurea therapy led to significant increases in both the hemoglobin and fetal hemoglobin levels. Dose-limiting toxic events regarding laboratory variables occurred in 5.1% of the participants, which was below the protocol-specified threshold for safety. During the treatment phase, 20.6 dose-limiting toxic effects per 100 patient-years occurred, as compared with 20.7 events per 100 patient-years before treatment. As compared with the pretreatment period, the rates of clinical adverse events decreased with hydroxyurea use, including rates of vaso-occlusive pain (98.3 vs. 44.6 events per 100 patient-years; incidence rate ratio, 0.45; 95% confidence interval [CI], 0.37 to 0.56), nonmalaria infection (142.5 vs. 90.0 events per 100 patient-years; incidence rate ratio, 0.62; 95% CI, 0.53 to 0.72), malaria (46.9 vs. 22.9 events per 100 patient-years; incidence rate ratio, 0.49; 95% CI, 0.37 to 0.66), transfusion (43.3 vs. 14.2 events per 100 patient-years; incidence rate ratio, 0.33; 95% CI, 0.23 to 0.47), and death (3.6 vs. 1.1 deaths per 100 patient-years; incidence rate ratio, 0.30; 95% CI, 0.10 to 0.88).ConclusionsHydroxyurea treatment was feasible and safe in children with sickle cell anemia living in sub-Saharan Africa. Hydroxyurea use reduced the incidence of vaso-occlusive events, infections, malaria, transfusions, and death, which supports the need for wider access to treatment. (Funded by the National Heart, Lung, and Blood Institute and others; REACH ClinicalTrials.gov number, NCT01966731 .).

Original publication

DOI

10.1056/nejmoa1813598

Type

Journal

The New England journal of medicine

Publication Date

01/2019

Volume

380

Pages

121 - 131

Addresses

From Centre Hospitalier Monkole, Kinshasa, Democratic Republic of Congo (L.T.); the Department of Medicine, University Health Network and Mt. Sinai Hospital, and the University of Toronto, Toronto (G.T.); the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Program, Kilifi, Kenya (T.N.W.); the Department of Medicine, Imperial College London, London (T.N.W.); Hospital Pediátrico David Bernardino, Luanda, Angola (B.S.); Mbale Clinical Research Institute and Mbale Regional Referral and Teaching Hospital-Busitema University, Mbale, Uganda (P.O.-O.); the Division of Hematology, Department of Pediatrics, Cincinnati Children's Hospital (A.L., S.E.S., T.S.L., P.T.M., R.E.W.), University of Cincinnati College of Medicine (A.L., P.T.M., R.E.W.), and the Global Health Center, Cincinnati Children's Hospital Medical Center (S.E.S., P.T.M., R.E.W.), Cincinnati; and Cohen Children's Medical Center, New Hyde Park, and the Zucker School of Medicine at Hofstra/Northwell, Hempstead - both in New York (B.A.).

Keywords

REACH Investigators, Humans, Malaria, Pain, Anemia, Sickle Cell, Hydroxyurea, Antisickling Agents, Dose-Response Relationship, Drug, Child, Child, Preschool, Infant, Africa South of the Sahara, Neglected Diseases