A multicenter study to describe the immunogenic epitope(s) of factor VIII in previously treated patients with congenital hemophilia A who develop de novo factor VIII inhibitors while receiving factor VIII infusion therapy - N/A

• Conditions: Haemophilia A is an X-linked recessive clotting disorder in which the clotting factor, factor VIII (FVIII), is deficient or inactive. Patients with low levels of FVIII have an increased tendency to bleed and is characterised by recurrent haemorrhages due to trauma, surgery or spontaneous haemorrhaging when the condition is severe.

• Registration Number: EUCTR2004-000219-24-DE
• Lead Sponsor: Wyeth Pharmaceuticals

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Study Start: 2006-06-26
• Last Update Posted: 1 May 2012

Recruitment & Eligibility

• Status: ot Recruiting
• Sex: All
• Target Recruitment: 27

Inclusion Criteria

Inhibitor positive hemophilia A patients:
1. Written informed consent or assent, as applicable.
2. Patients with moderate or severe congenital hemophilia A (FVIII:C <5%) .
3. Patients with at least one positive de novo* inhibitor result (> the upper limit of normal as defined by the laboratory performing the assay), attributable by the Investigator to the patient’s current FVIII product, at the time of study visit and a positive inhibitor result confirmed by the central laboratory.
4. Patients with exposure to at least two different FVIII products during their lifetime.
5. Patients with > 50 cumulative ED to FVIII products.
6. Patients able to comply with a 72-hour FVIII washout period.

*de novo inhibitor is defined as no known history of FVIII inhibitor titer.

Comparison group (inhibitor-free patients):
1. Written informed consent / assent, as applicable.
2. Patients with moderate or severe congenital hemophilia A (FVIII:C < 5%).
3. Patients with exposure to at least two different FVIII products during their lifetime.
4. Patients with > 50 cumulative exposure days to FVIII products.
5. Documented negative FVIII BIA at the time of the study visit (< the upper limit of normal as defined by the laboratory performing the assay).

Are the trial subjects under 18? yes
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range
F.1.3 Elderly (>=65 years) yes
F.1.3.1 Number of subjects for this age range

Exclusion Criteria

Inhibitor positive hemophilia A patients:
1. Patients with a negative FVIII inhibitor result (< or equal to the upper limit of normal as defined by the laboratory performing the assay) at the study visit.
2. Patients with known history of an inhibitor (> the upper limit of normal as defined by the laboratory performing the assay) prior to their current inhibitor.
3. Patients who have not had at least 1 FVIII BIA performed during the last 5 years prior to their visit for this study.
4. Patients who have received FVIII immune tolerance therapy at any time.
5. Patients, who as of the study visit, have taken only one FVIII product during their lifetime.
6. For patients whose current inhibitor is attributable to treatment with ReFacto; treatment with ReFacto prior to their previous product. In other words patients who were previously treated with ReFacto, then switched to another product, then switched back to ReFacto.
7. Patients with immune disorders (e.g., HIV, myeloma, lymphoma).

Comparison group (inhibitor-free patients):
1. Patients with a positive FVIII inhibitor result (> the upper limit of normal as defined by the laboratory performing the assay) at the time of the study visit.
2. Patients with a prior history of FVIII inhibitor (> the upper limit of normal as defined by the laboratory performing the assay).
3. Patients with immune disorders (e.g., HIV, myeloma, lymphoma).

Study & Design

• Study Type: Interventional clinical trial of medicinal product
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Main Objective: To describe the patterns of antibodies and associated epitopes in a subset of patients with hemophilia A, who meet the protocol entry criteria, using the methodology described in the protocol.;Secondary Objective: N/A;Primary end point(s): The endpoint will be a descriptive presentation of epitope regions of FVIII in samples from the three patient groups, using the methodology described in the protocol.