Hydroxyurea to Prevent Central Nervous System (CNS) Complications of Sickle Cell Disease in Children


7 United States sites


12 to 54 Years




Phase 2

Study type








About the study

This is a pilot study of hydroxyurea versus placebo to reduce central nervous system
complications (abnormally fast blood flow to the brain, silent cerebral infarct or stroke) in
young children with sickle cell disease. The investigators plan to identify children 12 to 48
months old without central nervous system complications and randomly assign 20 to treatment
with hydroxyurea and 20 to treatment with placebo for 36 months. Neither the study doctors
nor the participants will know which treatment they are receiving.

participation requirements

for Screening

1. Participant must have sickle cell anemia (hemoglobin SS) or sickle Beta-zero (null)
thalassemia (hemoglobin S-B0) as confirmed at the local institution by hemoglobin
analysis after six months of age.

2. Participant must be 9 to 48 months of age. All screening procedures except MRI can be
completed between 9 and 12 months of age, with the exception of the MRI, for which the
child must have reached the age of 12 months.

3. Informed consent must be signed by the participant’s legally authorized guardian
acknowledging written consent to join the study.

participation restrictions

for Screening

1. History of a focal neurologic event lasting more than 24 hours with medical
documentation or a history of prior overt stroke.

2. Other neurological problems, such as neurofibromatosis, lead poisoning, non-febrile
seizure disorder, or tuberous sclerosis.

3. Known human immunodeficiency virus (HIV) infection.

4. Treatment with anti-sickling drugs or hydroxyurea within 3 months or anticipated
treatment during the course of the study.

5. Chronic blood transfusion therapy, ongoing or planned.

6. Poor adherence likely per his/her hematologist and study coordinator based on previous
compliance in clinic appointments and following advice.

7. Presence or planned permanent (or semi-permanent) metallic structures attached to
their body. (e.g., braces on teeth), which their physicians believe will interfere
with the MRI of the brain.

8. History of two or more TCD studies with a velocity ≥ 200 cm/sec by the non-imaging
technique, or ≥185 cm/sec for the imaging technique or a indeterminate TCD.

9. Significant cytopenias [absolute neutrophil count (ANC) <1500/ul, platelets <150,000/ul, reticulocytes <80,000/ul, unless the hemoglobin is > 9 g/dl]. Cytopenias
will be considered transient exclusions.

10. Other significant organ system dysfunction

11. Known allergy or intolerance of hydroxyurea

12. Significant prematurity (gestational age of < 32 weeks)


  • Birmingham, Alabama, United States, University of Alabama, 35233
  • Baltimore, Maryland, United States, Sinai Hospital, 21215
  • Baltimore, Maryland, United States, Johns Hopkins Hospital, 21287
  • Kansas City, Missouri, United States, Mercy Children's Hospital, 64108
  • Saint Louis, Missouri, United States, St. Louis Children's Hospital, 63110
  • New York, New York, United States, Columbia University, 10032
  • Philadelphia, Pennsylvania, United States, Children's Hospital of Philadelphia, 19104