Given large absolute numbers of individuals with sickle cell disease in Nigeria, hydroxyurea therapy for all individuals with sickle cell disease may not be initially feasible; however, a targeted strategy of hydroxyurea use for primary prevention of strokes is an alternative to the standard therapy (observation) for high-risk individuals. The investigators propose a feasibility study, Sickle Cell Disease - Stroke Prevention in Nigeria (SPIN) Trial, to determine whether hydroxyurea can be used for primary prevention of strokes in Nigerian children with sickle cell anemia.
Sickle cell disease (SCD) is the most common genetic disease in the world. Approximately 150,000 Nigerian children are born each year with SCD, making it the country with the largest burden of sickle cell disease in the world. SCD is the most common cause of stroke in children and results in considerable morbidity in affected children. The current primary prevention approach of regular monthly blood transfusion therapy of children at high risk of stroke (identified by elevated transcranial Doppler measurements) is not feasible in a low income country such as Nigeria due to scarcity of supply, cost, and high rate of blood borne infections. In the United States, hydroxyurea (HU) is standard therapy for adults with SCD and may be a reasonable prevention alternative to regular blood transfusion for treatment of primary stroke in high-risk children. Given large absolute numbers of individuals with SCD in Nigeria, HU therapy for all individuals with SCD may not be initially feasible; however, a targeted strategy of HU use for primary prevention of strokes is an alternative to the standard therapy (observation) for high-risk individuals. Study investigators therefore propose a feasibility study to determine the acceptability of HU for primary prevention of strokes in Nigerian children with sickle cell anemia (SCA) in preparation for a National Institute of Health (NIH) sponsored Phase III Trial. Investigators will establish a safety protocol for using HU in a clinical trial setting and complete the necessary preparations for a definitive phase III trial. To accomplish these aims study investigators have assembled a strong multidisciplinary team representing Vanderbilt University and two premier in-country institutions: Aminu Kano Teaching Hospital, Nigeria, and Friends in Global Health-Nigeria. Completion of a definitive trial will not only benefit children with SCA in sub-Saharan Africa, where the majority of children with SCA live in the world, but could provide reasonable evidence for an alternative to blood transfusion therapy for the primary prevention of strokes in the US. To our knowledge this would be the first stroke prevention trial in Nigeria and could establish a precedent to expand to secondary stroke prevention for children and adults with SCA, as regrettably, no therapy is available to prevent recurrent stroke in these high-risk patients in resource-poor nations.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
29
Hydroxyurea will be prescribed as an investigational therapy by the treating physician. Recommended guidelines for titration of hydroxyurea to maximal tolerated dose are below. The study intervention will include hydroxyurea to begin at \~20 mg/kg/day (range 17.5 - 26 mg/kg/day). No dose escalation will occur as this dose was shown to have some efficacy in infants with SCA and was associated with rare myelosuppression.(1)
Aminu Kano Teaching Hospital
Kano, Nigeria
Hydroxyurea Therapy Acceptance and Adherence
The primary outcome measure will be adherence to daily administration of hydroxyurea. If adherence rate is less than 55%, alternative strategies must be considered for the definitive Phase III Trial.
Time frame: 5 years
Hydroxyurea Safety protocol for Children with Sickle Cell Anemia
Study investigators will evaluate the use of a standard safety protocol, non-dose escalating, for hydroxyurea in children with sickle cell anemia using a protocol similar to the recently completed National Heart Lung and Blood Institute (NHLBI) Baby HUG study, published in Lancet.(1) Study investigators expect the proportion of serious adverse reactions, as well as hydroxyurea-related morbidity and mortality, to be very small compared to the benefits. Study investigators will compare the frequency of severe adverse events and hydroxyurea toxicity related events that are associated with hospitalization in those receiving hydroxyurea (n= 60) to those who had normal transcranial Doppler measurements (n= 210) over the course of one year.
Time frame: 12 Months
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