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

This study has been completed.
University of Vermont
Information provided by (Responsible Party):
Edward Gomperts, Children's Hospital Los Angeles Identifier:
First received: February 6, 2009
Last updated: January 31, 2017
Last verified: January 2017
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.

Condition Intervention
Hemophilia A
Other: FVIII immuno-assay

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Basic Science
Official Title: Pharmacokinetic (PK) Analysis of a Novel Immunoassay in Hemophilia A

Resource links provided by NLM:

Further study details as provided by Children's Hospital Los Angeles:

Primary Outcome Measures:
  • The level of Factor VIII in pMols [ Time Frame: 48 hours ]

Secondary Outcome Measures:
  • The possible role of VWF, factor concentrate type and non-inhibitory antibody presence or absence on the FVIII antigen levels [ Time Frame: 48 hours ]

Enrollment: 7
Study Start Date: September 2006
Study Completion Date: February 2009
Primary Completion Date: September 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: FVIII immuno-assay
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
There is no intervention. This is a study of the differences in assays.

Detailed Description:
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.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00839202

United States, Vermont
Department of Biochemistry University of Vermont
Burlington, Vermont, United States, 05446
Sponsors and Collaborators
Children's Hospital Los Angeles
University of Vermont
Principal Investigator: Edward D Gomperts, MD Children's Hospital Los Angeles
Principal Investigator: Kenneth G Mann, PhD University of Vermont
  More Information

Responsible Party: Edward Gomperts, Attending Hematologist, Children's Hospital Los Angeles Identifier: NCT00839202     History of Changes
Other Study ID Numbers: CCI-06-0069-CR002
Study First Received: February 6, 2009
Last Updated: January 31, 2017
Individual Participant Data  
Plan to Share IPD: No

Keywords provided by Children's Hospital Los Angeles:
factor VIII
hemophilia A

Additional relevant MeSH terms:
Hemophilia A
Blood Coagulation Disorders, Inherited
Blood Coagulation Disorders
Hematologic Diseases
Coagulation Protein Disorders
Hemorrhagic Disorders
Genetic Diseases, Inborn
Factor VIII
Coagulants processed this record on March 28, 2017