Hydroxyurea Therapy To Prevent Incident Stroke Among Children With Sickle Cell Anaemia In Jamaica: The Extend Trial

Incident stroke, both primary and recurrent are common in children with sickle cell anemia (SCA) in Jamaica with incidences of 7.8% by 14 years of age and 29/100 person-years respectively. Cerebral vasculopathy manifested by elevated transcranial doppler (TCD) velocity (>170 cm/sec) is the major risk factor for both with a prevalence of 19.8% among Jamaican children with SCA. Chronic blood transfusion is the standard of care to reduce stroke risk and recurrence in children with SCA in high income countries, but in low-resource settings where blood availability, safety and local acceptance are limited, hydroxyurea (HU) is emerging as a viable alternative. However, the efficacy of HU for incident stroke prevention in children with newly diagnosed severe cerebrovascular disease without the use of transfusions in a low resource setting like Jamaica is unclear. The EXpanding Treatment for Existing Neurological Disease (EXTEND) trial (ClinicalTrials.gov NCT02556099) was designed to investigate the effects of open label HU on TCD velocities after 18 months of treatment, compared to the pre-treatment value. Secondary aims included the effects of HU on the incidence of neurological events including magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) changes, non-neurological events, hematological responses and toxicity.