Blood factor monitoring assay and uses thereof
View Patent ↗The present disclosure provides methods and compositions for diagnosing and treating subject having a bleeding disorder. The disclosed methods comprise contacting a sample, e.g., a blood or plasma sample obtained from the patient, with an activation mixture comprising an activated coagulation factor and a phospholipid mixture, wherein the activation mixture is dried onto a solid substrate. Also provided is a global hemostasis test based on the integration of clotting time (Ct) and pharmacokinetics data. The methods and compositions presented can be applied to point-of-care diagnostic systems.
1. A method of treating a bleeding disorder in a patient in need thereof comprising:
a) measuring the time between contacting of a sample obtained from the patient with an activation mixture dried on a solid substrate and the onset of clotting, thereby calculating the clotting time (Ct),
wherein the activation mixture comprises (i) an activated Factor IX (FIXa) and (ii) a phospholipid mixture,
wherein the Ct is used to determine a pharmacokinetic (PK) parameter of a coagulation factor, wherein the coagulation factor comprises a Factor VIII (FVIII),
wherein the PK parameter is a terminal half-life (HL) or a time to trough (T),
wherein the HL is calculated according to the following formula:
HL=−0.693×( T 2 −T 1 )× A /(Ct 1 −Ct 2 ),
wherein A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, T 1 and T 2 are times at which Ct is measured, and Ct 1 and Ct 2 are Ct values measured at T 1 and T 2 , respectively,
wherein the T is calculated according to the following formula:
T =−1.44×HL/( A ×(Ct measured −Ct trough ),
wherein A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, and HL is the terminal half-life, Ct measured is Ct measured at certain time point, and Ct trough is patient-specific clot time at trough, and
b) administering an effective amount of the coagulation factor at a dosing interval based on the PK parameter.
2. A method of treating a bleeding disorder in a patient in need thereof comprising:
a) measuring the time between contacting of a sample obtained from the patient with an activation mixture dried on a solid substrate and the onset of clotting, thereby calculating the clotting time (Ct),
wherein the activation mixture comprises (i) an activated Factor XI (FXIa) and (ii) a phospholipid mixture,
wherein the Ct is used to determine a pharmacokinetic (PK) parameter of a coagulation factor, wherein the coagulation factor comprises a Factor IX (FIX),
wherein the PK parameter is a terminal half-life (HL) or a time to trough (T),
wherein the HL is calculated according to the following formula:
HL=−0.693×( T 2 −T 1 )× A /(Ct 1 −Ct 2 ),
wherein, for each coagulation factor, A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, T 1 and T 2 are times at which Ct is measured, and Ct 1 and Ct 2 are Ct values measured at T 1 and T 2 , respectively,
wherein the T is calculated according to the following formula:
T =−1.44×HL/( A ×(Ct measured −Ct trough ),
wherein for each coagulation factor, A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, and HL is the terminal half-life, Ct measured is Ct measured at certain time point, and Ct trough is patient-specific clot time at trough, and
b) administering an effective amount of the coagulation factor at a dosing interval based on the PK parameter.
3. The method of claim 1 , wherein the correlation between Ct and a coagulation factor level (% Factor) is calculated based on the following formula:
Ct= A ×Ln(% Factor)+ B
wherein, for each coagulation factor, A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, and B is a patient-specific off-set value.
4. The method of claim 1 , further comprising monitoring the efficacy of the coagulation factor administered to the patient.
5. The method of claim 1 , wherein the PK parameter is terminal half-life (HL).
6. The method of claim 1 , wherein the PK parameter is time to trough (T).
7. The method of claim 6 , wherein the patient is administered a new dose of the coagulation factor every T interval.
8. The method of claim 1 , wherein the sample is selected from the group consisting of whole blood, citrated or equivalently stabilized blood, plasma, and other fluid sample containing or suspected of containing a coagulation factor.
9. The method of claim 8 , wherein the sample further comprises an added inhibitor.
10. The method of claim 1 , wherein the Ct correlates with a therapeutically efficacious treatment.
11. The method of claim 1 , wherein the FVIII is a chimeric FVIII polypeptide comprising FVIII and a non-FVIII polypeptide, wherein the non-FVIII polypeptide increases a half-life of the FVIII and comprises Fc, albumin, a PAS sequence, transferrin, C-terminal peptide of hCG (CTP), polyethylene glycol (PEG), hydryoxyethyl starch (HES), or two or more combinations thereof.
12. The method of claim 2 , wherein the FIX is a chimeric FIX polypeptide comprising FIX and a non-FIX polypeptide, wherein the non-FIX polypeptide increases a half-life of the FIX and comprises Fc, albumin, a PAS sequence, transferrin, C-terminal peptide of hCG (CTP), polyethylene glycol (PEG), hydryoxyethyl starch (HES), or two or more combination thereof.
13. The method of claim 11 , wherein the chimeric FVIII polypeptide comprises a monomer dimer hybrid comprising the FVIII and an Fc.
14. The method of claim 12 , wherein the chimeric FIX polypeptide comprises a monomer dimer hybrid comprising the FIX and an Fc.
15. The method of claim 2 , wherein the correlation between Ct and a coagulation factor level (% Factor) is calculated based on the following formula:
Ct= A ×Ln(% Factor)+ B,
wherein A is a constant value corresponding to the slope of a Ct versus coagulation factor concentration dose-response, and B is a patient-specific off-set value.
16. The method of claim 2 , further comprising monitoring the efficacy of the coagulation factor administered to the patient.
17. The method of claim 2 , wherein the PK parameter is terminal half-life (HL).
18. The method of claim 2 , wherein the PK parameter is time to trough (T).
19. The method of claim 18 , wherein the patient is administered a new dose of the coagulation factor every T interval.
20. The method of claim 2 , wherein the sample is selected from the group consisting of whole blood, citrated or equivalently stabilized blood, plasma, and other fluid sample containing or suspected of containing a coagulation factor.
21. The method of claim 20 , wherein the sample further comprises an added inhibitor.
22. The method of claim 2 , wherein the Ct correlates with a therapeutically efficacious treatment.