REACH is a prospective, phase I/II open-label dose escalation trial of hydroxyurea for children with confirmed SCA between 3 and 10 years of age. The short-term goal is to obtain critical pilot data regarding the feasibility, safety, and benefit of hydroxyurea for children with SCA in multiple distinct research settings in Africa. Based on that information, the longer-term goal is to make hydroxyurea more widely available for children with SCA in Africa, particularly those identified with SCA through expanded newborn screening programs.

REACH is a prospective, phase I/II open-label dose escalation trial of hydroxyurea for children with confirmed SCA between 3 and 10 years of age. The short-term goal is to obtain critical pilot data regarding the feasibility, safety, and benefit of hydroxyurea for children with SCA in multiple distinct research settings in Africa. Based on that information, the longer-term goal is to make hydroxyurea more widely available for children with SCA in Africa, particularly those identified with SCA through expanded newborn screening programs. In the REACH prospective trial, the Original Cohort will receive long-term treatment while for the New Cohort, treatment will continue at least 4 years using PK-guided dosing after an initial 3-month screening period.

Inclusion Criteria

1. Pediatric patients with documented sickle cell anemia (typically HbSS supported by hemoglobin electrophoresis, complete blood count, and peripheral blood smear)
2. In the Original Cohort, age range of 1.00-9.99 years, inclusive, at the time of enrollment (now age 5.5 - 17.5 years); age range 3.0-10.0 years for the New Cohort
3. Weight at least 10.0 kg at the time of enrollment
4. Parent or guardian willing and able to provide written informed consent, with child's verbal assent as per local IRB/Ethics Board requirements
5. Willingness to comply with all study-related treatments, evaluations, and follow-up

Exclusion Criteria

1. Known medical condition making participation ill-advised (e.g., acute or chronic infectious disease, HIV, or malignancy)

2. Acute or chronic severe malnutrition determined by impaired growth parameters as defined by WHO (weight for length/height or height for age >3 z-scores below the median WHO growth standards.

3. Pre-existing severe hematological toxicity (temporary exclusions)

   1. Anemia: Hb <4.0 g/dL
   2. Anemia: Hb <6.0 g/dL with ARC <100 x 109/L
   3. Reticulocytopenia: ARC <80 x 109/L with Hb <7.0 g/dL
   4. Thrombocytopenia: Platelets <80 x 109/L
   5. Neutropenia: ANC <1.0 x 109/L

4. Blood transfusion within 60 days before enrollment (temporary exclusion)

5. In the Original Cohort, hydroxyurea use within 6 months before enrollment (temporary exclusion). In the New Cohort, the children should be hydroxyurea naïve, without any prior treatment exposure.

Investigators whose proposed use of the data has been approved by a review committee identified for this purpose, will be provided individual participant data that underlie the results reported from this study, after de-identification and publication. The data can be obtained via email to Dr. Ware as the corresponding author.

Nine months following publication ending 36 months following publication.

For individual participant data meta-analysis after approval of a proposal and with a signed data access agreement.