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Protocol - Population-based Pharmacokinetic Study Using Chromogenic Substrate Assay - Extended Half-life Factor VIII Products

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Description:

This protocol provides instructions and guidance for collecting and processing samples for coagulation testing, performing a population-based pharmacokinetic study using the chromogenic substrate assay, and interpreting pharmacokinetic results in response to infusion of extended half-life Factor VIII products. Because there are many comparable assays for performing the chromogenic substrate assay, the protocol also provides basic guidelines to aid comparability among different studies.

Specific Instructions:

The PhenX Hemophilia Inhibitor Research Working Group (WG) notes that these measures are intended for use in observational and interventional trials but are not sufficient to define hemophilia phenotypes when used in isolation.

The WG recommends that when measuring inhibitor recovery in non-severe patients, endogenous factor should be measured by the same assay that was optimized prior to inhibitor development.

The WG recommends that Factor VIII and IX assays, either by one-stage clotting factor or chromogenic substrate methodology, should be performed by a laboratory that is College American Pathologists (CAP) accredited or Clinical Laboratory Improvement Amendments of 1998 (CLIA) certified. For multi-center clinical trials, the use of a central laboratory is strongly encouraged.

The WG notes that in comparison to the one-stage clotting factor assay, the chromogenic substrate assay demonstrates less variation by reagents, thus enabling cross-laboratory comparisons.

Protocol:

Population-based Pharmacokinetic Study Using Chromogenic Substrate Assay - Extended Half-life Factor VIII Products

Sample Collection

The PhenX Hemophilia Inhibitors Working Group (WG) recommends that investigators follow the sample collection procedures outlined in Lippi et al. (2012) to ensure quality specimens for coagulation testing. These recommendations include basic criteria for venipuncture (e.g., proper patient identification, use of correct techniques, appropriate devices and needles) as well as additional guidance for critical parameters which can affect the outcome of clot-based tests. These critical parameters include prevention of prolonged venous stasis, collection of nonhemolyzed samples, order of blood draw, and appropriate filling and mixing of collection tubes.

Additionally, the WG highlights that blood should be collected by direct venipuncture into 3.2% sodium citrate tubes and filled within 11% of fill line. A second tube should be collected. A discard tube should be drawn if using a winged butterfly collection system.

Sample Processing

The WG recommends that investigators follow the sample collection procedures outlined in Adcock Funk et al. (2012). The procedures include that:

  • unprocessed or processed sodium citrate samples remain capped and at room temperature until testing,
  • samples should not be refrigerated or stored on ice or in an ice bath,
  • samples should be transported vertically, and
  • processed samples should not be agitated during transportation to avoid remixing of components.

Additionally, samples can be transported and stored as:

  • unprocessed sodium citrate whole blood samples,
  • whole blood samples centrifuged and maintained in sodium citrate tubes, or
  • plasma processed by centrifugation and aliquoted into a second tube.

Ideally, whole blood samples should be processed to platelet poor plasma (PPP) within 1 hour of collection and assayed within 4 hours of collection.

If centrifuging samples, the centrifuge should be validated so that post-centrifuged samples contain less than 10,000 platelets/microliter. Centrifuged and processed plasma can be stored at -20o C for 2 weeks and should be transferred to < -70o C for longer storage, including shipment.

Extended Half-life Factor VIII Products: Chromogenic Substrate Assay

The WG notes that there are a number of different assays and instruments that are appropriate to perform the chromogenic substrate assay. Once an assay is chosen for a particular study, the WG recommends that no changes in the protocol be made over the course of the study. Because results can vary with the instrumentation and reagents, the WG recommends that the investigator record the make and manufacturer of equipment, the repeatability and coefficients of variation for the assay, and the reagents used.

Extended Half-life Factor VIII Products: Population-based Pharmacokinetic Study

The WG recommends that investigators follow parameters outlined by the International Society on Thrombosis and Haemostasis Subcommittee on Factor VIII, Factor VIII and Rare Coagulation Disorders (Iorio et al., 2017). These parameters include taking two to three measurements at least 12 hours apart in the after a routine dose of the extended half-life product (i.e., no washout period and no standardized dose) at the following timepoints:

  • 4-8 hours after infusion;
  • 16-28 hours after infusion; and
  • 40-60 hours after infusion.

In addition, investigators should take a sample 60-84 hours after infusion.

Extended Half-life Factor VIII Products: Population-based Pharmacokinetics Model

Investigators should use a "robust" population pharmacokinetics model, such as WAPPS-Hemo or PKFit.

Protocol Name from Source:

N/A; see source.

Availability:

Publicly available

Personnel and Training Required

Phlebotomist

Equipment Needs
Laboratory with the ability to perform the chromogenic substrate assay.
Requirements
Requirement CategoryRequired
Major equipment No
Specialized training No
Specialized requirements for biospecimen collection Yes
Average time of greater than 15 minutes in an unaffected individual Yes
Mode of Administration

Bioassay

Life Stage:

Toddler, Child, Adolescent, Adult

Participants:

Any age

Selection Rationale

The PhenX Hemophilia Inhibitors Working Group selected the recommendations from Lippi et al. (2012) and Adcock Funk et al. (2012) as the best standardized methodology for collecting and processing samples for coagulation testing. The International Society on Thrombosis and Haemostasis (Iorio et al., 2017) provides recommended parameters for consistent implementation of the pharmacokinetic study.

Language

English

Standards
StandardNameIDSource
Derived Variables

None

Process and Review

Not applicable.

Source

Adcock Funk, D. M., Lippi, G., & Favaloro, E. J. (2012). Quality standards for sample processing, transportation, and storage in hemostasis testing. Seminars in Thrombosis and Hemostasis, 38(6), 576-585.

Iorio, A., Blanchette, V., Blatny, J., Collins, P., Fischer, K., & Neufeld, E. (2017). Estimating and interpreting the pharmacokinetic profiles of individual patients with hemophilia A or B using a population pharmacokinetic approach: Communication from the SSC of the ISTH. Journal of Thrombosis and Haemostasis, 15(12), 2461-2465.

Lippi, G., Salvagno, G. L., Montagnana, M., Lima-Oliveira, G., Guidi, G. C., & Favaloro, E. J. (2012). Quality standards for sample collection in coagulation testing. Seminars in Thrombosis and Hemostasis, 38(6), 565-575.

General References

lvarez-Romn, M. T., Fernandez-Bello, I., de la Corte-Rodrguez, H., Hernndez-Moreno, A. L., Martn-Salces, M., Butta-Coll, N., Rivas-Pollmar, M. I., Rivas-Muoz, S., & Jimnez-Yuste, V. (2017). Experience of tailoring prophylaxis using factor VIII pharmacokinetic parameters estimated with myPKFiT in patients with severe haemophilia A without inhibitors. Haemophilia, 23(1), e50-e54.

Blanchette, V. S., Key, N. S., Ljung, L. R., Manco-Johnson, M. J., van den Berg, H. M., & Srivastava, A.; Subcommittee on Factor VIII, Factor VIII and Rare Coagulation Disorders of the Scientific and Standardization Committee of the International Society on Thrombosis and Hemostasis. (2014). Definitions in hemophilia: Communication from the SSC of the ISTH. Journal of Thrombosis and Haemostasis, 12(11), 1935-1939.

Hay, C. R., & DiMichele, D. M.; International Immune Tolerance Study. (2012). The principal results of the International Immune Tolerance Study: A randomized dose comparison. Blood, 119(6), 1335-1344.

Iorio, A., Edginton, A.N., Blanchette, V., Blatny, J., Boban, A., Cnossen, M., Collins, P., Croteau, S.E., Fischer, K., Hart, D.P., Ito, S., Korth-Bradley, J., Lethagen, S., Lillicrap, D., Makris, M., Matht, R., Morfini, M., Neufeld, E.J., Spears, J. (2018). Performing and interpreting individual pharmacokinetic profiles in patients with Hemophilia A or B: Rationale and general considerations. Research and Practice in Thrombosis and Haemostasis, 2(3), 535-548.

Iorio, A., Keepanasseril, A., Foster, G., Navarro-Ruan, T., McEneny-King, A., Edginton, A. N., & Thabane, L.; WAPPS-Hemo Co-investigator Network. (2016). Development of a Web-Accessible Population Pharmacokinetic Service-Hemophilia (WAPPS-Hemo): Study protocol. JMIR Research Protocols, 5(4), e239.

Kitchen, S., Kershaw, G., & Tiefenbacher, S. (2016). Recombinant to modified factor VIII and factor VIII Chromogenic and one-stage assays issues. Haemophilia, 22(Suppl. 5), 72-77.

Lee, M., Morfini, M., Schulman, S., & Ingerslev, J.; Factor VIII/Factor VIII Scientific and Standardization Committee of the International Society for Thrombosis and Haemostasis. (2001). Scientific and Standardization Committee communication. The design and analysis of pharmacokinetic studies of coagulation factors. https://www.isth.org/members/group_content_view.asp?group=100348&id=159244. Retrieved August 30, 2018.

Peyvandi, F., Oldenburg, J., & Friedman, K. D. (2006). A critical appraisal of one-stage and chromogenic assays of factor VIII activity. Journal of Thrombosis and Haemostasis, 14(2), 248-261.

Teichman, J., Chaudhry, H. R., & Sholzberg, M. (2018). Novel assays in the coagulation laboratory: A clinical and laboratory perspective. Transfusion and Apheresis Science, 57(4), 480-484.

Protocol ID:

911204

Variables:
Export Variables
Variable NameVariable IDVariable DescriptionVersiondbGaP Mapping
PX911204_Factor_Eight_Population_Chromogenic_Extended_One_Stage_Clotting_Factor_Assay_Changes PX911204030100 Were any changes made in the protocol over more
the course of the study? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_One_Stage_Clotting_Factor_Assay_Record PX911204030200 Were the make and manufacturer of equipment, more
repeatability and coefficients of variation for the assay, and the reagents used recorded? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Model PX911204050000 Was a "robust" population pharmacokinetics more
model, such as WAPPS-Hemo or PKFit, used? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study PX911204040100 Were the parameters outlined by the more
International Society on Thrombosis and Haemostasis Subcommittee on Factor VIII, Factor VIII and Rare Coagulation Disorders (Iorio et al., 2017) followed? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study_After_Infusion_Hours_16 PX911204040400 Was Factor VIII activity tested 16-28 hours more
after infusion? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study_After_Infusion_Hours_4 PX911204040300 Was Factor VIII activity tested 4-8 hour more
after infusion? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study_After_Infusion_Hours_40 PX911204040500 Was Factor VIII activity tested 40-60 hours more
after infusion? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study_After_Infusion_Hours_60 PX911204040600 Was Factor VIII activity tested 60-84 hours more
after infusion? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Pharmacokinetic_Study_Infusion_Baseline PX911204040200 Was Factor VIII activity tested before more
infusion (baseline)? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection PX911204010100 Were the sample collection procedures more
outlined in Lippi et al. (2012) followed? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Blood_Draw PX911204010400 Was the order of blood draw recorded? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Nonhemolyzed PX911204010300 Were nonhemolyzed samples collected? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Tubes PX911204010500 Were collection tubes filled and mixed as more
outlined in Lippi et al. (2012)? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Tubes_Discard PX911204011000 Was a discard tube drawn? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Tubes_Filled PX911204010700 Were the tubes filled within 11% of the fill line? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Tubes_Second PX911204010800 Was a second tube collected? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Tubes_Winged PX911204010900 Was a winged butterfly collection system used? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Venipuncture PX911204010600 Was blood collected by direct venipuncture more
into 3.2% sodium citrate tubes? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Collection_Venous_Statsis PX911204010200 Were steps taken to prevent prolonged venous more
stasis? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing PX911204020100 Were the sample collection and processing more
procedures outlined in Adcock Funk et al. (2012) followed? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Agitation PX911204020500 Were samples agitated during transportation? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Assayed PX911204021000 Were samples assayed within 4 hours of collection? N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Centrifuge_Validated PX911204021100 Was the centrifuge validated so that process more
results in less than 10,000 platelets/microliter show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Deep_Freeze PX911204021300 Was the sample transferred to <= -70 C, more
including shipment? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Frozen PX911204021200 Was the sample frozen immediately and stored more
at -20 C for at most 2 weeks? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Platelet_Poor_Plasma PX911204020900 Were samples processed to platelet poor more
plasma (PPP) within 1 hour of collection? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Refrigerated PX911204020300 Were samples refrigerated or stored on ice more
or in an ice bath? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Sodium_Citrate PX911204020200 Did unprocessed or processed sodium citrate more
samples remain capped and at room temperature until testing? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Storage_Plasma PX911204020800 Were samples stored as plasma processed by more
centrifugation and aliquoting into a second tube? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Storage_Unprocessed PX911204020600 Were samples stored as unprocessed sodium more
citrate whole blood samples? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Storage_Whole_Blood PX911204020700 Were samples stored as whole blood samples more
centrifuged and maintained in sodium citrate tubes? show less
N/A
PX911204_Factor_Eight_Population_Chromogenic_Extended_Sample_Processing_Transportation PX911204020400 Were samples transported vertically? N/A
Hemophilia Inhibitor Research
Measure Name:

Response to Factor VIII Infusion - Population-based Pharmacokinetic Study

Release Date:

May 7, 2019

Definition

A series of plasma Factor VIII activity determinations in blood samples are obtained immediately prior to, and at timepoints after, infusion of FVIII concentrate.

Purpose

The results of the population-based pharmacokinetic study (i.e., initial recovery and half-life) can be used to guide prophylactic dosage of standard and extended half-life Factor VIII products in hemophiliacs who do not have FVIII inhibitors.

Keywords

Hemophilia inhibitors, Factor VIII, FVIII, hemophilia A, inhibitors, pharmacokinetic study, population pharmacokinetic study, popPK, prophylaxis, half-life, recovery