Study Evaluating On-Demand Treatment With BeneFIX In Chinese Subjects

Investigator Hemostatic Efficacy Assessment was based on response of bleeding episodes to BeneFIX treatment on 4-point rating scale: Excellent(1): definite pain relief or improvement in signs of bleeding starting within 8 hrs after infusion, with no additional infusion; Good(2): definite pain relief or improvement in signs of bleeding starting within 8 hrs or following infusion; Moderate(3): probable or slight improvement starting after 8 hours following infusion; No Response(4): no improvement at all between infusions or during 24 hour interval following an infusion, or condition worsens.

Investigator Hemostatic Efficacy Assessment was based on response of bleeding episodes to BeneFIX treatment on 4-point rating scale: Excellent(1): definite pain relief or improvement in signs of bleeding starting within 8 hrs after infusion, with no additional infusion; Good(2): definite pain relief or improvement in signs of bleeding starting within 8 hrs or following infusion; Moderate(3): probable or slight improvement starting after 8 hours following infusion; No Response(4): no improvement at all between infusions or during 24 hour interval following an infusion, or condition worsens.

Incidence of FIX inhibitor was defined as any result determined as positive at local laboratory, and confirmed at central laboratory with Nijmegen assay result >=0.6 Bethesda Unit (BU). Incidence was stratified by participant exposure history - Minimally Treated Patients (MTPs): those who had received at least one prior FIX infusion, and <= 100 documented Exposure Days (EDs); while Previously Treated Patients (PTPs): those who had received >100 documented prior EDs. When number of prior EDs for an individual was not known to be at least 100, participants were included in the MTP population.

The number of BeneFIX infusions required to treat each bleeding episode were analyzed. The average frequency of BeneFIX infusions per hemorrhage incidence to treat every hemorrhage was equal to the total number of injections throughout the study divided by total number of hemorrhagic events.

FIX recovery was assessed by evaluating FIX:C after initial exposure and following 6 months of repeated exposures to BeneFIX. A modified FIX recovery study was performed at Day 1 (Visit 2) and Month 6/Final/Early Termination visits (Visit 4) and when clinically indicated at the applicable on-demand visits. Blood samples for determination of FIX:C were collected immediately before BeneFIX infusion and at 30 minutes (±5 minutes) after the start of infusion. Post-infusion blood samples were collected via venipuncture in arm contralateral to arm used for infusion.

The incidence of LETE for on-demand treatment was defined as no response after each of 2 successive infusions within 24 hours for the same bleeding event in the absence of confounding factors.

Hypersensitivity to undesirable (damaging, discomfort-producing and sometimes fatal) reactions produced by the normal immune system. Hypersensitivity reactions require a pre-sensitized (immune) state of the host.

Thrombosis is the formation of a blood clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss.

RBC Agglutination is the clumping of red blood cells in the presence of an antibody. The antibody or other molecule bonded multiple particles and joined them, creating a large complex.