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.
- Hydroxyurea (Hydrea® and Droxia®
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Other Names: Droxia; Hydrea; Mylocel Intervention Desc: 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) ARM 1: Kind: Experimental Label: Hydroxyurea Description: We propose to enroll 40 children with SCA and an elevated TCD measurement between 5 and 12 years of age in this one arm feasibility study of hydroxyurea therapy, with follow-up of at least 12 months per subject. 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) with 200 mg capsules of hydroxyurea. Dosing will be based on weights as follows: 18 kg to 22.9 kg- 2 capsules; 23 kg to 33.9 kg- 3 capsules; 34 kg to 44.9 kg- 4 capsules. No dose escalation will occur as this dose was shown to have some efficacy with rare myelosuppression toxicity.(2)
- Masking: Open Label
- Purpose: Treatment
- Endpoint: Safety/Efficacy Study
- Intervention: Single Group Assignment
|Type||Measure||Time Frame||Safety Issue|
|Primary||Acceptability of hydroxyurea therapy for primary prevention of strokes in children with sickle cell anemia.||2 years||No|
|Secondary||Establish a safety protocol for using hydroxyurea for primary prevention of strokes in a clinical trial setting for one year in a low income country.||12 Months||No|
|Primary||Hydroxyurea Therapy Acceptance and Adherence||2 years||No|
|Secondary||Hydroxyurea Safety protocol for Children with Sickle Cell Anemia||12 Months||No|