Activity and Content of Factor VIII (FVIII) in Human Plasma: The Assessment of a Novel Immunoassay

Study Overview
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Brief Summary
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A novel immuno-assay is being evaluated for the measurement of Factor VIII. Current procedure measures a rate assay which is subject to much artefact. The hypothesis is that the new assay will give a reading of absolute quantities of FVIII which will provide a more suitable indicator of FVIII content for clotting factor manufacturers, physicians and patients.

Detailed Description
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Remnant samples collected in a clinical laboratory are assayed with the new procedure and compared with the standard functional activated partial thromboplastin time (APTT) assay. A PK study in seven study subjects with hemophilia A is being carried out using five different commercially licensed factor VIII concentrates and the blood samples drawn for the PK analysis are being measured for FVIII with the novel assay and compared with the standard APTT assay. The concentrates used in the PK studies are also being applied to the two assay systems to determine each product's specific activity.

Official Title
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Pharmacokinetic (PK) Analysis of a Novel Immunoassay in Hemophilia A

Conditions
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Hemophilia A

Intervention / Treatment
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* Other: FVIII immuno-assay


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adults with hemophilia A factor VIII less that 2% informed consent signed absence of an inhibitor Exclusion Criteria: history of a high responding inhibitor anemia

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FVIII immuno-assay<br>The study is not designed as a therapeutic evaluation, but an assessment of clotting factor VIII timed responses after the infusion of specified doses of licensed clotting factor VIII concentrates. The purpose of the study is to measure the levels of infused licensed clotting factor VIII by standard assay techniques and comparing these standard assays with an experimental assay. Measurements of possible co-factors that might impact the results were also carried out. | Other: FVIII immuno-assay<br>* There is no intervention. This is a study of the differences in assays.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The level of Factor VIII in pMols |  | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The possible role of VWF, factor concentrate type and non-inhibitory antibody presence or absence on the FVIII antigen levels |  | 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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factor VIII, hemophilia A, assay