Profile of crizanlizumab and its potential in the prevention of pain crises in sickle cell disease: evidence to date

Sickle cell disease (SCD) is one of the most common inherited blood disorders globally. It is a grouping of autosomal recessive genetic disorders identified by a genetic mutation that replaces glutamic acid with valine at the sixth amino acid on the hemoglobin beta-globin chain. Millions of people around the world live with a severe genotype of SCD that is often associated with occlusion of the microvasculature resulting in episodes of severe pain and multiple organ system dysfunction. These episodes, commonly categorized as vaso-occlusive crises (VOC), are a distinctive clinical presentation of SCD which represents the majority of SCD morbidity and associated hospitalizations. Though the complete process by which these crises occur is complex and not fully outlined, evidence reveals this process to be multifactorial and heterocellular. For nearly two decades, hydroxyurea was the only FDA-approved therapy for SCD. Evidence to date shows that hydroxyurea treatment significantly reduces the rate of VOC, hospitalizations, and mortality. Despite these benefits, adherence remains problematic due to a variety of adverse effects and interpatient variability connected with hydroxyurea therapy. Crizanlizumab, an adhesion inhibitor of sickled red blood cells, was recently granted breakthrough therapy designation. Results of a phase 2 study have reported a successful reduction in annual rates of vaso-occlusive crisis with a favorable safety profile. This paper reviews the available literature concerning crizanlizumab use in patients with SCD.