Growth and puberty in African children with sickle cell anemia treated with hydroxyurea.

abstractChildren with sickle cell anemia (SCA) have poor growth and pubertal development. REACH (Realizing Effectiveness Across Continents with Hydroxyurea) is a prospective trial evaluating the feasibility, safety, and benefits of hydroxyurea at maximum tolerated dose (MTD) for children with SCA in sub-Saharan Africa. Children aged 1 to 10 years received open-label hydroxyurea with longitudinal follow-up. Height, weight, and pubertal staging were collected over 7 years of treatment. Biomarkers included insulin-like growth factor I (IGF-I), IGF-binding protein 3, luteinizing hormone, follicle-stimulating hormone, and anti-Mullerian hormone (AMH). Hydroxyurea commenced at an average (mean ± 1 standard deviation [SD]) age of 5.9 ± 2.4 years (range, 1.6-10.2) for girls (n = 296) and 5.4 ± 2.4 years (range, 1.3-10.1) for boys (n = 310). Using natural history SCA-specific reference curves, the mean weight-for-age z score improved from 0.47 ± 0.90 at enrollment to 0.69 ± 1.00 on hydroxyurea treatment. Height increased from 0.26 ± 0.90 to 0.42 ± 1.00 on treatment, and body mass index from 0.46 ± 1.00 to 0.85 ± 1.20. IGF-I remained low in many participants. Puberty was delayed in 25% to 30% of children, with gradual progress on treatment. AMH was low (<2.5th percentile) in 4% of girls, whereas 52% of boys had low AMH at baseline and 28% at follow-up. Long-term hydroxyurea treatment at MTD is associated with beneficial effects on growth with improved weight and height, and does not negatively affect pubertal developmenty in children with SCA in sub-Saharan Africa. This study was registered at www.clinicaltrials.gov initially as NCT01966731 and is now registered as NCT06171217 for long-term follow-up.