Abelacimab is a novel fully human monoclonal antibody that acts as a dual inhibitor of Factor XI and Factor XIa.

It targets the catalytic domain of Factor XI, preventing its activation and thereby reducing the levels of functional Factor XI.

It offers a hemostasis-sparing anticoagulation approach, which is particularly useful in the prevention and treatment of thromboembolic events.

Factor XI has emerge as a target for anticoagulants that have the potential to be safer than other available agents because factor  XI is essential for thrombosis but non-essential in most cases for hemostasis.

People with genetically mediated factor XI deficiency have few embolic events without appreciable increase in the occurrence of spontaneous bleeding.

Abelacimab is effective in reducing the risk of venous thromboembolism (VTE) postoperatively.

It was superior to enoxaparin in preventing postoperative VTE after total knee arthroplasty, with a lower incidence of thrombosis and a comparable safety profile regarding bleeding risks.

Pharmacokinetic and pharmacodynamic studies indicate that abelacimab has a long terminal elimination half-life of 25 to 30 days, and it significantly reduces free FXI levels shortly after administration.

Among patients with atrial fibrillation  at moderate to high risk for a stroke, treatment with abelacimab resulted in markedly lower levels of free factor XI, fewer bleeding events than treatment with rivaroxaban.

Both intravenous and subcutaneous administrations have been shown to be safe and well-tolerated in clinical trials.