Xisomab 3G3(Oregon Health & Science University)

Thrombosis remains one of the leading causes of death in the world. The history of anticoagulation has evolved considerably from non-specific drugs (i.e., heparins and vitamin K antagonists, VKA) to agents that directly target specific coagulation factors (i.e., argatroban, fondaparinux and direct oral anticoagulants, DOAC). Since the last decade, DOAC are widely used in clinical practice because of their ease to use with favorable pharmacological profile and not requiring monitoring, particularly for venous thromboembolism treatment and prevention and stroke prevention in atrial fibrillation. However, despite having a better safety profile than VKA, their bleeding risk is not negligible. Therefore, research is underway to develop new anticoagulant therapies with a better safety profile. One of these news approaches to reduce the risk of bleeding is to target the coagulation in the intrinsic pathway, in particular the contact activation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data with patients with inherited factor XI (FXI) deficiency and preclinical studies, FXI emerged as the most promising candidate target separating hemostasis from thrombosis. This review summaries the role of FXI and FXIa in hemostasis, provides evidence of initial success with FXI pathway inhibitors in clinical trials (such as IONIS-FXI_Rx, fesomersen, osocimab, abelacimab, milvexian, asundexian or xisomab 3G3) and highlights the opportunities and challenges for this next generation of anticoagulants.

Cardioembolic stroke, associated to nonvalvular atrial fibrillation (NVAF), accounts for approximately one in every four strokes. Cardioembolic stroke has a bad prognosis and is associated with a significant rate of recurrence.

This article reviews current pharmacotherapeutic options for prevention of stroke in NVAF, paying special attention to their use in particular clinical settings (e.g. cardioversion, catheter ablation). We also aim to review new drug candidates that have entered clinical studies in this indication.

Oral anticoagulant therapy (OAT) remains the mainstay for ischemic stroke prophylaxis in NVAF in patients at risk. Several oral (asundexian, milvexian) and parenteral (abelacimab, osocimab, xisomab, IONIS-FXI_RX, fesomersen) factor XIa inhibitors are under development. These new compounds appear to be associated with a low bleeding tendency and have the potential to complement current existing alternatives for anticoagulation. However, it is also of paramount importance to implement interventions to improve adherence to available anticoagulants, which is currently suboptimal. Non-anticoagulant drugs, such as colchicine, metformin and dronedarone, also being investigated to reduce the burden of NVAF and cardioembolic stroke. Additional clinical data are needed to more clearly define the role of these drugs for stroke prevention in NVAF.