# US 10,501,773 B2 · Detection and classification of an anticoagulant using a clotting assay

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- Number: US 10,501,773 B2
- Document ID: US10501773B2
- Status: Granted
- Kind: B2
- Application number: 14/813,939
- Filed: 2015-07-30
- Published: 2016-02-04
- Granted: 2019-12-10
- Earliest claimed: 2014-07-31
- Assignees: Haemonetics Corporation
- Applicants: Haemonetics Corporation
- Inventors: Fowzia S. Zaman; Marc Doubleday
- Web page: https://patentgrep.com/patent/US10501773B2

## CPC

- C12Q 1/56: involving blood clotting factors, e.g. involving thrombin, thromboplastin, fibrinogen
- G01N 33/86: involving blood coagulating time {or factors, or their receptors}
- G01N 2333/96444: Factor X (3.4.21.6)
- C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

In some embodiments, the invention provides methods for detecting and/or classifying an anticoagulant at a therapeutically relevant amount or higher in a patient, including subjecting a sample of a control blood component (known not to contain the anticoagulant) to a clotting assay in the presence of a Factor Xa reagent to obtain a control clotting measurement; and subjecting a sample of a blood component from a patient suspected of having the anticoagulant to the clotting assay in the presence of the Factor Xa reagent to obtain a patient clotting measurement, wherein the patient clotting measurement sample greater than the control clotting measurement indicates the presence of the anticoagulant at a therapeutically relevant amount or higher in the patient. In some embodiments, the invention includes methods for classifying an anticoagulant as an anti-Factor Xa or a direct thrombin inhibitor anticoagulant using a clotting assay in the presence of an ecarin reagent.

## Claims

### Claim 1

A method for treating a patient suspected of having either an anti-Factor Xa or a direct thrombin inhibitor (DTI) anticoagulant at a therapeutically relevant amount or higher, the method comprising:
a. detecting the anticoagulant by:
i. obtaining a sample of a blood component from the patient,
ii. performing a first viscoelastic clotting assay in the presence of a Factor Xa reagent in a first sample of a blood component from the patient to obtain a patient Factor Xa clotting measurement;
iii. obtaining a control sample of a blood component that lacks an anticoagulant;
iv. and performing a viscoelastic clotting assay in the presence of a Factor Xa reagent in the control sample to obtain a control Factor Xa clotting measurement;
wherein the presence of the anti-Factor Xa anticoagulant and the presence of the DTI anticoagulant are capable of being detected;
wherein the patient Factor Xa clotting measurement that is at least 1.25 times greater than the control Factor Xa clotting measurement indicates the presence of the anti-Factor Xa anticoagulant or the presence of the DTI anticoagulant at a therapeutically relevant amount or higher in the patient, and
wherein the patient Factor Xa clotting measurement less than or equal to the control Factor Xa clotting measurement indicates the absence of both the anti-Factor Xa anticoagulant and the DTI anticoagulant at a therapeutically relevant amount or higher in the patient; and
b. if the presence of the anti-Factor Xa anticoagulant or the presence of the DTI anticoagulant at a therapeutically relevant amount or higher in the patient is detected, classifying the anticoagulant by:
i. obtaining a second sample of a blood component from the patient identified as having an anticoagulant at a therapeutically relevant amount or higher;
ii. performing a second viscoelastic analysis clotting assay to obtain a patient ecarin clotting measurement;
iii. obtaining a control sample of a blood component that lacks an anticoagulant; and
iv. performing a viscoelastic clotting assay in the presence of an ecarin reagent in the control sample to obtain a control ecarin clotting measurement;
wherein a patient ecarin clotting measurement that is at least 1.25 times greater than the control ecarin clotting measurement identifies the detected anticoagulant as the DTI anticoagulant in the patient, and wherein a patient ecarin clotting measurement less than or equal to the control ecarin clotting measurement identifies the detected anticoagulant as the anti-Factor Xa anticoagulant in the patient; and
administering to the patient identified as having a DTI anticoagulant a therapeutically relevant amount of a reversal agent that reverses the DTI anticoagulant, or administering to the patient identified as having an anti-Factor Xa a therapeutically relevant amount of a reversal agent that reverses the anti-Factor Xa anticoagulant.

### Claim 2 (depends on 1)

The method of claim 1, wherein the viscoelastic analysis is performed using a container containing the sample on an interior of the container.

### Claim 3 (depends on 2)

The method of claim 2, wherein the viscoelastic analysis is performed using the container and a pin, wherein the pin moves relative to the container or the container moves relative to the pin.

### Claim 4 (depends on 2)

The method of claim 2, wherein the container lacks a bottom surface.

### Claim 5 (depends on 1)

The method of claim 1, wherein the patient is a human.

### Claim 6 (depends on 1)

The method of claim 1, wherein the patient is undergoing a condition selected from the group consisting of: surgery, trauma, bleeding, stroke and a thromboembolic event.

### Claim 7 (depends on 1)

The method of claim 1, wherein the anticoagulant is an oral anticoagulant.

### Claim 8 (depends on 1)

The method of claim 1, wherein the control Factor Xa clotting measurement is a range, average or median of at least two Factor Xa clotting measurements of at least two control blood components known to lack the anticoagulant.

### Claim 9 (depends on 1)

The method of claim 1, wherein the control ecarin clotting measurement is a range, average or median of at least two ecarin clotting measurements of at least two control blood components known to lack the anticoagulant.

### Claim 10 (depends on 1)

The method of claim 1, wherein the reversal agent that reverses the DTI anticoagulant is selected from the group consisting of prothrombin complex concentrate (PCC) and idarucizumab.

### Claim 11 (depends on 1)

The method of claim 1, wherein the reversal agent that reverses the anti-Factor Xa anticoagulant is andexanet.