Crizanlizumab in sickle cell disease.

ABSTRACT

Vaso-occlusion in sickle cell disease (SCD) leads to a myriad of manifestations driving morbidity and mortality in patients with SCD. Increased leucocyte adhesion and P-selectin expression on platelets and endothelial cells is an inciting event that leads to obstruction of microcirculation by adhesion with rigid sickled red blood cells. Crizanlizumab is a first-in-class monoclonal antibody that inhibits P-selectin and has been shown to decrease the frequency of vaso-occlusive pain crises in patients with SCD in clinical trials. The role of crizanlizumab in other manifestations of SCD still needs further investigation.

There are more than 100,000 people in the USA living with sickle cell anemia, which is a form of the inherited blood disorder, sickle cell disease. Patients with sickle cell anemia are typically diagnosed through newborn screening programs. They are also diagnosed during times of vaso-occlusive pain crisis, where patients present with severe pain without an obvious cause, and also through hemolytic anemia, a disorder in which red blood cells are destroyed faster than they can be made. While children typically survive into adulthood, the life expectancy of those with sickle cell remains shorter secondary to the after-effects of chronic sickling, where the hemoglobin inside red blood cells sticks or clumps together, causing the cell to become fragile. The associated complications of chronic sickling include pulmonary hypertension (high blood pressure in the arteries of the lung and the right side of the heart), heart failure, stroke, liver dysfunction and splenic infarction, where the blood flow to the spleen is compromised. Crizanlizumab is a new therapy targeting P-selectin, a protein that blocks interaction with p-selectin glycoprotein ligand, and has shown promise in reducing vaso-occlusive crises.