Crizanlizumab is a monoclonal antibody used for the prevention of vaso-occlusive crises (VOCs) in patients with sickle cell disease (SCD). Crizanlizumab binds to P-selectin, a cell adhesion molecule expressed on the surface of activated endothelial cells and platelets. By inhibiting P-selectin, crizanlizumab helps prevent the adhesion of sickle red blood cells to the endothelium and other blood cells, which is a key step in the initiation of VOCs in patients with SCD. It is indicated for the prevention of VOCs in patients with SCD. Vaso-occlusive crises are episodes of severe pain caused by the blockage of blood flow in small blood vessels, leading to tissue ischemia and organ damage. Crizanlizumab aims to reduce the frequency and severity of these painful episodes.