Study of Propranolol as Anti-Adhesive Therapy in Sickle Cell Disease (SCD)

An open label, prospective, randomized cross-over phase II study in up to 60 sickle cell patients who are either homozygous for Hb S or have HbSB0 thalassemia. Initially, each patient will be treated for 6 weeks with placebo or a standard dose of propranolol (40 mg) every 12 hrs. This will be followed by a 2-week washout period after which, patients will receive the other treatment modality (placebo or propranolol). We Hypothesize that propranolol administered in vivo on a daily basis for 6 weeks (1) will decrease baseline adhesion to endothelial cells and will substantially abrogate epinephrine-stimulated adhesion to endothelial cells, as measured in vitro; (2) will improve biomarkers of endothelial activation and dysfunction; and (3) can be safely used in patients with SCD. Thus, the use of propranolol in SCD may represent a safe and effective means of anti-adhesive therapy in SCD. Study Objectives: Primary Objective: • To establish the safety and efficacy of long-term therapy with propranolol as an anti-adhesive therapy for SCD. Secondary Objective: • To evaluate changes in soluble markers of endothelial activation and dysfunction. Correlative Science Objective: • To determine whether response to propranolol therapy is associated with polymorphisms in genes encoding the proteins involved in the upregulation of Sickle Red Blood Cell (SS RBC) adhesion by epinephrine.