Tissue factor and phosphatidylserine-positive procoagulant complex (TF-PS complex)

The target refers to the procoagulant assembly formed on the surface of apoptotic vesicles or microparticles, characterized by the co-exposure of phosphatidylserine (PS) and tissue factor (TF). In physiological conditions, PS is restricted to the inner leaflet of the cell membrane, but it flips to the outer surface during apoptosis or cell activation, providing a critical anionic scaffold for the recruitment of vitamin K-dependent coagulation factors (PMID: 19154450). Tissue factor, the primary initiator of the extrinsic coagulation pathway, is often present on these same vesicles, especially those derived from tumor cells or activated monocytes (PMID: 24458210). Together, PS and TF facilitate the formation of the tenase (FVIIIa-FIXa) and prothrombinase (FVa-FXa) complexes, leading to a massive burst of thrombin generation and subsequent fibrin clot formation. This procoagulant surface is a major driver of cancer-associated thrombosis and is targeted by therapeutic agents such as bavituximab, which binds PS to disrupt the coagulation scaffold, and tisotumab vedotin, which targets TF to deliver cytotoxic payloads (PMID: 33831368). These therapies aim to disrupt the assembly of coagulation factors or exploit the unique membrane composition of the tumor microenvironment for targeted delivery. Understanding this target is crucial for developing site-specific anticoagulants and tumor-targeted therapies that address the prothrombotic state in malignancy and inflammatory diseases.

Other names

General blood coagulation components via apoptotic vesicle surface phosphatidylserine and tissue factorProcoagulant microvesiclesTissue factor-bearing apoptotic bodiesPhosphatidylserine-exposed procoagulant surfaceExtrinsic Xase and prothrombinase complex scaffold

Drugs targeting this complex function by either masking the phosphatidylserine catalytic surface to prevent factor assembly, inhibiting the initiator tissue factor to block the extrinsic pathway, or directly inhibiting the resulting activated serine proteases (Factors Xa and IIa) that utilize this surface for their catalytic activity.