Study Evaluating The Efficacy And Safety Of Xyntha In Children Less Than 6 Years Of Age

• Percentage of Participants With Factor VIII (FVIII) Inhibitor Development [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: Yes ]
  Incidence of inhibitor development was defined as any result determined positive at a central laboratory (Bethesda inhibitor titer of >=0.6 BU/mL) using Nijmegen modification of the Bethesda assay.
  
  
• Percentage of Participants With Less Than Expected Therapeutic Effects (LETE) in the On-Demand Setting [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  LETE in the on-demand setting was based on the response to the treatment of a bleeding episode. LETE in the on-demand setting occurred if the participant recorded 2 successive "No Response" ratings (indicated there was no improvement at all between infusions or during the 24 hour interval following an infusion, or condition worsened) after 2 successive Xyntha infusions, respectively. The infusions was to be administered within 24 hours (=<24 hours) of each other for the treatment of the same bleeding event in the absence of confounding factor.
  
  
• Percentage of Participants With LETE in the Prophylaxis Setting [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  The LETE in the prophylaxis setting was the occurrence of a bleed. LETE in the prophylaxis setting occurred if there was a spontaneous bleed within 48 hours (=<48 hours) after a regularly scheduled prophylactic dose of Xyntha (which was not used to treat a bleed) in the absence of confounding factors.
  
  
• Percentage of Participants With Low Recovery LETE [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  The LETE could be considered lower than expected recovery of FVIII in the opinion of the investigator following infusion of Xyntha in the absence of confounding factors.
  
  

• Mean Annualized Bleed Rate (ABR) [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  An annualized bleeding rate (ABR) for each participant was calculated as the number of bleeds requiring administration of FVIII replacement product (taken from the electronic Infusion Log Diary), divided by his total therapy duration (in days), and then multiplied by 365.25.
  
  
• Number of Xyntha Infusions Needed to Treat Each New Bleed [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  The data from the electronic Infusion Log Diary plus the Test Article case report form (CRF) was used to determine the number of infusions administered to treat a bleed. This was calculated by adding the initial 'for a new bleed' (on demand) infusion to any subsequent (on demand) infusions for the (same) 'previously treated bleed'. An on-demand infusion for a 'previously treated bleed' was counted toward the bleed with the most recent start time prior to that infusion.
  
  
• Response to First On-demand Xyntha Treatment for All New Bleeds as Assessed by the Caregiver [ Time Frame: Baseline to 24 months or early withdrawal ] [ Designated as safety issue: No ]
  A 4-point response scale to be completed is as defined as follows: (Excellent: definite pain relief/improvement in signs of bleeding starting within 8 hrs after an infusion, with no additional infusion; Good: definite pain relief/improvement in signs of bleeding starting within 8 hrs or following the infusion; Moderate: probable/slight improvement starting after 8 hours following the infusion; No Response: no improvement at all between infusions).
  
  
• Mean Number of Breakthrough (Spontaneous/Non-traumatic) Bleeds [ Time Frame: Baseline to 24 months or early withdrawal. ] [ Designated as safety issue: No ]
  The number of breakthrough (spontaneous/non-traumatic) bleeds within 48 hours following a prophylaxis dose of Xyntha was summarized. The data from the electronic Infusion Log Diary plus the Test Article CRF was used to determine the number of infusions administered to treat a new bleed, counting only those infusions administered =<48 hours after an infusion marked as 'prophylaxis' (which had no associated bleed).
  
  

The study was terminated on 22 Sept 2009 due to competition with another Wyeth study for a similar patient population. The decision to terminate the trial was not based on any safety issues.