Study Group:
- Written informed consent or assent, as applicable.
- Subjects with moderate to severe Hemophilia B (FIX:C or class III allergic manifestations within 24 hours of a BeneFIX infusion.
Control Group:
- Written informed consent or assent, as applicable.
- Subjects with moderate to severe Hemophilia B (FIX:C
Study group:
- Subjects who had no reaction when rechallenged with BeneFIX, in the absence of
prophylactic immunomodulating therapy.
- Subjects whose most recent allergic manifestations with BeneFIX occurred >36 months
prior to providing written informed consent for this study.
- Subjects who have taken antihistamine, steroidal, or other immunosuppressive therapy
within 72 hours of the scheduled visit for this study.
- Subjects with immune disorders.
- Subjects unable to comply with a minimum 5-day FIX washout requirement.
Control group:
- Subjects with documented evidence of prior allergic reaction to any FIX product.
- Subjects with documented evidence of prior or current FIX inhibitor (BU >0.6).
- Subjects have taken antihistamine, steroidal, or other immunosuppressive therapy
within 72 hours of the scheduled study blood draw.
- Subjects with immune disorder.
- Subjects unable to comply with a minimum 5-day FIX washout requirement.