Crizanlizumab is a medicine under development for the preventative treatment of SCD painful crisis. Circulating platelets (type of cells in the blood that has a role in blood clotting and stopping of bleeding) in SCD patients express higher levels of P-selectin, a protein that drives the blockage of blood vessels. Crizanlizumab acts by blocking P-selectin and thus can prevent blockage in small blood vessels and maintain blood flow. Therefore, if licensed, crizanlizumab will offer a new treatment option for patients with sickle cell-related pain crises.
Givosiran is made of a short, synthetic strand of genetic material called ‘small interfering RNA’ (siRNA) that has been designed to interfere with the production of an enzyme involved in an early step in making haem. By blocking this early step of haem production in patients with AHP, givosiran is expected to prevent the next steps which produce substances that accumulate in the body and cause the symptoms of the disease.