Novel Dose Escalation to Predict Treatment With Hydroxyurea

Sickle cell disease is a disorder in which red blood cells (RBCs) are abnormally shaped. This can result in painful episodes, serious infections, chronic anemia (a decrease in the number of red blood cells), and damage to body organs. Hydroxyurea therapy offers significant benefits for infants, children, and adolescents with sickle cell anemia. These include a reduction in the frequency of pain crises and acute chest syndrome (inflammation of the lungs) and an increase in hemoglobin (the oxygen-carrying protein) in the blood. Patients on hydroxyurea who receive a maximum tolerated dose (MTD) that is specific for them have greater clinical benefit than those who receive a standard lower dose. There is, however, no way currently to predict the MTD for individual patients. As such, MTD for each patient is currently determined by gradual increases in the dose over several months. This process is time-consuming, requires monthly clinic visits, and delays the benefits of hydroxyurea therapy. Our research group has come up with an equation that could be used to predict each patient's MTD using baseline clinical and laboratory measures before starting hydroxyurea treatment. The purpose of this research study is to compare the use of our equation for predicting MTD to the current standard practice of gradually increasing the hydroxyurea dose until MTD is reached. We want to see if the use of our predictive equation will allow us to achieve MTD faster and with no more side effects than with the standard practice.