Pharmacokinetics, Efficacy and Safety of Twice Daily Dosing Regimen of Hydroxycarbamide Dispersible Tablets in Children With Sickle Cell Disease

Inclusion Criteria: * Written informed consent, signed and dated by both parents or by the legally acceptable representative(s) of the children, and, if possible, assent from the children, * HbSS or HbSβ0 SCD, * Aged between 9 months and 11 years old, * Hydroxycarbamide naïve, * Parent(s) or legally acceptable representative(s) capable of communicating with the investigator and understanding the requirements and constraints of the study protocol and willing to comply with the study requirements, * Contraception criterion, if applicable: for patients who are sexually active * Affiliated to a social security plan or beneficiary of a similar insurance plan, * Patient must meet the following laboratory values : Absolute Neutrophil Count ≥ 1.0x109/L, Platelets ≥ 75x109/L and Haemoglobin (Hgb) \> 5.5 g/dL, * Transcranial Doppler (TCD) in the last 12 months indicating low risk for stroke is required for children over 18 months of age. Exclusion Criteria: * Participation in any other clinical study for any other pharmaceutical product within 4 weeks preceding the inclusion visit, * Patients who have had chronic blood transfusion or transfusion in the last 3 months preceding the inclusion visit, * Patients treated with other SCD-modifying therapies, * Patient with a stage 3, 4 or 5 chronic kidney disease, * Patients known to be infected with human immunodeficiency virus, hepatitis B virus, or hepatitis C virus, * Known hypersensitivity or allergy to the excipients, * Any surgical or medical condition or any significant illness that, in the opinion of the investigator, constitutes a risk or a contraindication to the participation of the patient to the study, or that may interfere with the objectives, conduct or evaluation of the study, * Female patients who are pregnant or lactating, * Any documented history of a clinical stroke or intracranial haemorrhage, or an uninvestigated neurologic finding within the past 12 months.