Haemophilia B is a genetic condition that is caused by a shortage in clotting factor IX (FIX). The severity of the haemophilia is determined by the clotting activity of FIX in the blood. The standard of care for patients with haemophilia B consists of substitution therapy with FIX. In this procedure, FIX, either prepared from human plasma or a recombinant form, is administered through an intravenous (IV) infusion with a frequency that depends on the severity of the haemophilia. These infusions are given once or twice a week and lay a heavy burden on patients. In addition to this, the presence of inhibitory antibodies in haemophilia patients can hamper the treatment. In these cases, FIX is no longer active, or is sometimes even eradicated. More recently, important advances have been made in the development of gene therapy for haemophilia B patients. With this technique, a non-mutated FIX gene is introduced into the DNA of patients using a viral vector that targets the hepatocytes of patients. As such, the missing clotting factor is reintroduced in patients allowing them to produce sufficient amounts of the clotting factor. During the 2016 annual EHA meeting, several haemophilia studies addressed this technique.

(BELG J HEMATOL 2016;7(4):174–5)