Pharmacological properties of betrixaban

Venous thromboembolism (VTE) in acute medically ill patients is a leading cause of in-hospital morbidity and mortality. A majority of these VTE events occur post-discharge, and patients remain at increased VTE risk for up to 3 months post-discharge. Recent clinical trials of extended-duration thromboprophylaxis with enoxaparin, rivaroxaban, and apixaban in acute medically ill patients did not demonstrate a net clinical benefit compared with in-hospital thromboprophylaxis, and were shown to be associated with higher risks of major bleeding. Betrixaban is a new direct oral anticoagulant (DOAC) with a different pharmacokinetic profile than other DOACs. Betrixaban has the longest half-life among the DOAC class, with a terminal half-life of 35-45 h and an effective half-life of 19-27 h. Betrixaban has a low peak-to-trough ratio compared with other anticoagulants and a predictable duration of drug exposure, leading to overall consistent anticoagulant effect over 24 h. Betrixaban is mainly cleared via the hepatobiliary system and therefore not contraindicated in patients with severe renal insufficiency. Betrixaban was recently approved for the indication of extended thromboprophylaxis in the United States based on the APEX trial of betrixaban 80 mg once daily for 35-42 days compared with low molecular weight heparin enoxaparin for 10 ± 4 days in hospitalized acute medically ill patients. This study demonstrated that extended-duration betrixaban reduced VTE compared with standard-duration enoxaparin in acute medically ill patients, without increased risk of major bleeding. This patient population at risk of VTE may benefit from extended prophylaxis, ensuring continuum of care from in-hospital to post-discharge.