Factor XI as a Drug Target for the Prevention and Treatment of Thrombosis

The optimal anticoagulation therapeutic intervention balances preventing or treating thrombosis, depending on the clinical scenario, and bleeding. A novel drug target, factor eleven (FXI), may theoretically represent a way to prevent thrombosis in the clotting cascade, without increasing the risk of bleeding. Several mechanisms for inhibiting FXI or its activated form are being studied and include antisense oligonucleotides, monoclonal antibodies, small molecules, natural peptides, and aptamers. Many of the drugs that have been developed have been studied in clinical trials evaluating their use in secondary prevention of acute coronary syndromes, prevention of venous thromboembolism after orthopedic surgery, and stroke and systemic embolism prevention. Ongoing areas of interest include special patient populations such as patients with end stage renal disease (ESRD), cancer, and COVID-19 infection. FXI inhibition is a novel concept with many drug mechanisms that exist and are in varying stages of clinical study for a number of clinical uses.