The present invention provides a heparin-insensitive assay for measuring the quantity of Factor XIa in a sample. The present invention provides a method for measuring the concentration of Factor XIa in a plasma sample by using enzymatic heparin degradation as sample pretreatment step.

The present disclosure concerns aptamers of formula (I) capable of specifically binding to Factor XIa. The aptamers can be used to prevent, treat or alleviate the symptoms of thrombosis. The aptamers can also be used to detect Factor XIa in a sample and/or purify Factor XIa from a sample. The aptamers can further be used to identity putative therapeutic agents for the prevention, treatment or alleviation of symptoms associated with thrombosis.

The present invention relates to the field of therapeutic monoclonal antibodies, and specifically provides an anti-FXI/FXIa antibody or an antigen-binding fragment thereof, nucleic acid molecules encoding same, and methods for preparing same. The anti-FXI/FXIa antibody or antigen-binding fragment thereof described in the present invention has specificity and high affinity to FXI/FXIa, and can effectively inhibit the activity of FXI/FXIa. Therefore, the present invention further provides a pharmaceutical composition comprising the antibody or antigen-binding fragment thereof, and a use thereof in the preparation of a drug which is used for the prevention and/or treatment of diseases or disorders related to coagulation or thromboembolism.

A highly sensitive blood coagulation test reagent that enables determining and evaluating bleeding risk of direct oral anticoagulants (DOACs) and the like accurately in hemorrhagic diseases, and the like are provided. A blood coagulation test reagent containing: an active form of a blood coagulation factor XI (FXIa); and tissue factor (TF). A blood coagulation test method including a step of measuring the amount of thrombin generated by reacting a biological sample as a test specimen with a test reagent containing: 0.5 pM to 1,000 pM of an active form of a blood coagulation factor XI(FXIa); and 1 fM to 1,000 fM of tissue factor.

Provided are methods and devices for evaluating coagulation, including the identification of a coagulation impairment such as a factor deficiency or the presence of a factor inhibitor. In various embodiments, the methods and devices measure coagulation of a sample in response to the addition of one or more coagulation factors, added at various concentrations to portions of the sample. Such coagulation measurements can be evaluated to accurately profile coagulation impairments of the sample. In additional various embodiments, point-of-care or bedside testing with a convenient, microfluidic device can be used by minimally trained personnel.

Various methods for evaluating hemostatic effect and various blood coagulation initiation reagents were studied to construct a method for evaluating blood coagulation reaction mediated by a substance having an activity of substituting for coagulation factor VIII (FVIII). As a result, it was discovered that by using a coagulation initiation reagent containing activated coagulation factor XI (FXIa) and phospholipids, the effect of a substance having an activity of substituting for coagulation factor VIII (FVIII) on blood coagulation reaction can be evaluated using the amount of thrombin generated in the blood sample as an indicator.

This disclosure relates to methods for detection and measurement of anti-drug antibodies (ADAs) against Factor XI and/or Factor XIa therapeutic antibodies, e.g., in a subject being treated with said Factor XI and/or Factor XIa therapeutic antibodies.

The present disclosure concerns aptamers of formula (I) capable of specifically binding to Factor XIa. The aptamers can be used to prevent, treat or alleviate the symptoms of thrombosis. The aptamers can also be used to detect Factor XIa in a sample and/or purify Factor XIa from a sample. The aptamers can further be used to identity putative therapeutic agents for the prevention, treatment or alleviation of symptoms associated with thrombosis.

The present invention relates to the field of therapeutic monoclonal antibodies, and specifically provides an anti-FXI/FXIa antibody or an antigen-binding fragment thereof, nucleic acid molecules encoding same, and methods for preparing same. The anti-FXI/FXIa antibody or antigen-binding fragment thereof described in the present invention has specificity and high affinity to FXI/FXIa, and can effectively inhibit the activity of FXI/FXIa. Therefore, the present invention further provides a pharmaceutical composition comprising the antibody or antigen-binding fragment thereof, and a use thereof in the preparation of a drug which is used for the prevention and/or treatment of diseases or disorders related to coagulation or thromboembolism.

The present invention relates to novel compounds suitable for the detection and/or inhibition of coagulation proteases, specifically APC, fIIa, fXa, and fXIa. The compounds have the structural formula 1 or X shown below:

##STR00001## in which R.sub.1, P.sub.1, P.sub.2, P.sub.3, P.sub.4, Z, R.sub.1x, A.sub.1, A.sub.2, A.sub.3, A.sub.4 and Z.sub.x are defined herein.

The present invention also relates to compositions comprising the compounds of formula I or formula X defined herein, to processes for synthesising these compounds and to their use for the treatment and/or detection of diseases and conditions in which coagulation proteases, in particular APC, fIIa, fXa, and fXIa, are implicated.