Hydroxycarbamide for very young children with sickle cell anaemia: no effect on the primary outcomes of spleen or kidney function, but evidence for decreased pain and dactylitis, with minimal toxicity.

Context Sickle cell anaemia (SCA) is a disorder of haemoglobin polymerisation that results in vaso-occlusion and haemolytic anaemia, culminating in organ injury and early mortality. Elevated fetal haemoglobin has been associated with a less severe phenotype leading to an interest in hydroxycarbamide (also known as hydroxyurea) use. The MSH study1 demonstrated that hydroxycarbamide in adults with severe sickle cell disease reduced painful events, hospitalisations, acute chest syndrome and the number of blood transfusions. The HUG–KIDS study,2 a phase I/II study, demonstrated safety and haematologic responses to hydroxycarbamide therapy in children 5–15 years of age. The HUSOFT study3 was conducted in infants and very young children for 2 years with similar end points and favourable results. Two adult trials document the benefi ts of hydroxycarbamide in reducing mortality in SCA.4 5 The BABY HUG study was designed to answer whether hydroxycarbamide given to infants with SCA for 2 years slows or delays organ damage.