BAX 326 Pediatric Study

Computed as total area under the first moment curve (total AUMC) divided by the total area under the concentration versus time curve (total AUC)

Computed as the dose divided by total Area under the curve (AUC)

The rise in FIX activity in IU/dL per unit dose administered in IU/kg. Calculated as follows: (FIX activity at post-infusion minus FIX activity at pre-infusion) divided by weight-adjusted dose

Calculated as log_e2/λ, where λ is the regression slope in the terminal phase of the least absolute deviations regression model

Computed as Clearance (CL) * Mean residence time (MRT)

IR calculated as follows: (FIX activity at post-infusion minus FIX activity at pre-infusion) divided by weight-adjusted dose. IR is determined at baseline (PK analysis), Week 5, Week 13 and Week 26 timepoints. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants > 6 years of age; pediatric participants 6 to <12 years of age; pharmacokinetic Full Analysis Set (PKFAS).

Rating Scale for Treatment of bleeding episodes (4-point ordinal scale): - Excellent: Full relief of pain and cessation of objective signs of bleeding (eg, swelling, tenderness, and decreased range of motion in the case of musculoskeletal hemorrhage) after a single infusion. No additional infusion required for the control of bleeding. Administration of further infusions to maintain hemostasis did not affect this scoring. - Good: Definite pain relief and/or improvement in signs of bleeding after a single infusion. Possibly requires more than 1 infusion for complete resolution. - Fair: Probable and/or slight relief of pain and slight improvement in signs of bleeding after single infusion. Required more than 1 infusion for complete resolution. - None: No improvement or condition worsens.

The annualized bleeding rate (ABR) during prophylaxis was calculated only for participants who had adequate treatment time for bleeding rate assessment (i.e., more than 3 months of prophylaxis treatment). The observation period for prophylaxis was to be the time between the first and the last prophylactic infusions. The treatment period for surgery was to be excluded from the bleed rate calculation. ABR calculated as (Number of bleeding episodes/observed treatment period in days) * 365.25.

Event includes prophylactic infusions of study product and infusions of study product for treatment of bleeding episodes (BEs).

If more than 2-dilution increase as compared to pre-study level at screening and titers verified for specificity in the confirmatory assay. AB=antibodies in category for outcome measure data.

Categories consist of Clinically Significant (CS) changes in haemaotology parameters, clinical chemistry parameters and vital signs. Abbreviations in categories; Clin=clinical; params=parameters

If more than 2-dilution increase as compared to pre-study level at screening and titers verified for specificity in the confirmatory assay.

For this study, the PedsQL™ questionnaires for participants 2 to 7 years of age (parent-proxy versions for age groups 2-4 years and 5-7 years) and PedsQL™ Child version for participants 8 to 12 years of age were used. The Peds-QL is a generic Health-Related Quality of Life (HR QoL) instrument designed specifically for a pediatric population. It captures the following domains: general health/activities, feelings/emotional, social functioning, school functioning. A 5-point score is used for each domain: from 0 (never) to 4 (almost always). Items are reversed scored and linearly transformed to a 0-100 scale as follows: 0=100, 1=75, 2=50, 3=25, 4=0 so that higher scores indicate better quality of life (QoL). The total score is the mean (average) of all scores from the 4 domains. The change from baseline in total score is reported- a positive score indicates a better QoL compared to baseline and a negative score indicates a poorer QoL compared to baseline.

The Haemo-QoL is a quality of life (QoL) assessment instrument for children and adolescents with haemophilia. As a hemophilia-specific instrument, this measure assesses very specific aspects of dealing with hemophilia. For the Haemo-QoL, higher scores indicate a worse quality of life. Scores on a scale range between 0 and 100.

The number of hospitalizations per participant. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants < 6 years of age; pediatric participants 6 to <12 years of age; Full Analysis Set.

The length of hospitalization per participant. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants < 6 years of age; pediatric participants 6 to <12 years of age; Full Analysis Set.

The number of unscheduled doctor's Office visits per participant. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants < 6 years of age; pediatric participants 6 to <12 years of age; Full Analysis Set.

The number of Emergency Room visits per participant. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants < 6 years of age; pediatric participants 6 to <12 years of age; Full Analysis Set.

The number of days lost from school per participant. Number of participants contributing data (N) for this outcome measure is included in the category title in the order: pediatric participants < 6 years of age; pediatric participants 6 to <12 years of age; Full Analysis Set.