Study of Recombinant Factor IX Fc Fusion Protein (rFIXFc) in Participants With Hemophilia B

Annualized bleeding episodes = (number of bleeding episodes / number of days in the respective period)\*365.25. In Arms 1 and 2, the efficacy period (EP) started with date and time of first prophylactic dose following a completed pharmacokinetic (PK) sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). In Arm 3, the EP started following last PK sampling timepoint and ended with either date of last contact or date of last entry into the eDiary, whichever was later. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc.

Estimated with a factor for arm, based on whole study duration for all participants. Annualized bleeding episodes = (number of bleeding episodes / number of days in the respective period)\*365.25. In Arms 1 and 2, the efficacy period (EP) started with date and time of first prophylactic dose following a completed PK sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). In Arm 3, the EP started following last PK sampling timepoint and ended with either date of last contact or date of last entry into the eDiary, whichever was later. The EP was interrupted for the repeat PK period in Arm 1 and for all surgical/rehabilitation periods in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc.

An inhibitor test result ≥0.6 Bethesda units (BU)/mL, identified and confirmed by re-testing of a second sample obtained within 2 to 4 weeks, was considered positive. Both tests were to be performed using the Nijmegen-modified Bethesda Assay by the central laboratory. The incidence rates along with the 95% CI were summarized for all titers for subjects with 50 or more exposure days (EDs) to rFIXFc and a valid inhibitor test after the 50th exposure. In addition, the incidence rates for all subjects regardless of their exposure days to rFIXFc were also summarized. The 95% CI was calculated using Clopper-Pearson exact method.

Time frame: up to 52 weeks ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of of rFIXFc and who had a valid inhibitor test; n=number of participants with given number of exposure days who had a valid inhibitor test.

AE=any untoward medical occurrence that did not necessarily have a causal relationship with this treatment, and could be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of study product, whether related or not. TEAE=AE present prior to receiving the first injection of BeneFIX or rFIXFc that subsequently worsened in severity or was not present prior to receiving the first injection but subsequently appeared before last visit on study. Participants are counted once if they report multiple events in the same system organ class (SOC) or preferred term (PT). Coded using the Medical Dictionary for Regulatory Activities (MedDRA), version 15.0 dictionary. The following SOCs are abbreviated in the table: Immune System (IS); Injury, Poisoning, and Procedural (IPP); Metabolism and Nutrition (MN); Musculoskeletal and Connective Tissue (MCT); Respiratory, Thoracic and Mediastinal (RTM); Skin and Subcutaneous Tissue (SST).

Time frame: up to 52 weeks + 30 days ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of BeneFIX or rFIXFc. A participant may have been in more than one group (i.e., participants in Arm 4 who were also in Arm 1, 2, or 3; please see Participant Flow for details).

Clinical laboratory evaluations included hematology and blood chemistry. Table does not include laboratory tests evaluated during the surgical/rehabilitation period. Because the perioperative management period represents a unique clinical situation, safety data obtained during the surgical/rehabilitation period for participants in Arm 4 were included in listings and reviewed separately. Review of the listing was sufficient to assess this endpoint. ULN=upper limit of normal.

Time frame: up to 52 weeks ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of BeneFIX or rFIXFc; n=the number of participants with at least one post-baseline value. For this study, a table was not generated for potentially clinically significant laboratory abnormalities for participants in the perioperative management/surgical arm (Arm 4).

AE=any untoward medical occurrence that did not necessarily have a causal relationship with this treatment, and could be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of study product, whether related or not. TE=event present prior to receiving the first injection of BeneFIX or rFIXFc that subsequently worsened in severity or not present prior to receiving the first injection but subsequently appeared before last visit on study. Serious AE (SAE)=AE resulting in death, immediate risk of death, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, or a congenital/anomaly/birth defect, or any other medically important event. Related=related, possibly related, and relationship missing. Data include AEs emergent during the surgical/rehabilitation period; AE data are included in each treatment arm only for the time each participant was enrolled in that arm.

Time frame: up to 52 weeks + 30 days ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of BeneFIX or rFIXFc. A participant may have been in more than one group (i.e., participants in Arm 4 who were also in Arm 1, 2, or 3; please see Participant Flow for details). Participants with at least one TESAE reported are included in the TEAE count.

SAE=AE resulting in death, immediate risk of death, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, or a congenital/anomaly/birth defect, or any other medically important event. TESAE=SAE present prior to receiving the first injection of BeneFIX or rFIXFc that subsequently worsened in severity or was not present prior to receiving the first injection but subsequently appeared before last visit on study. Participants are counted once if they report multiple events in the same system organ class (SOC) or preferred term (PT). Coded using the Medical Dictionary for Regulatory Activities (MedDRA), version 15.0 dictionary. The following SOC is abbreviated in the table: Injury, Poisoning, and Procedural (IPP).

Time frame: up to 52 weeks + 30 days ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of BeneFIX or rFIXFc. A participant may have been in more than one group (i.e., participants in Arm 4 who were also in Arm 1, 2, or 3; please see Participant Flow for details).

Annualized bleeding episodes = (number of bleeding episodes/number of days in efficacy period)\*365.25. Please see the definition of the efficacy period (EP) in the Outcome Measure 4 Description. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode. Any bleeding at a different location was a separate bleeding episode regardless of time from the last injection.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc with evaluable data.

Annualized bleeding episodes = (number of bleeding episodes/number of days in efficacy period)\*365.25. Please see the definition of the efficacy period (EP) in the Outcome Measure 4 Description. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode. Any bleeding at a different location was a separate bleeding episode regardless of time from the last injection.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc with evaluable data.

Consumption is calculated for the efficacy period (EP). In Arms 1 and 2, the EP started with date and time of first prophylactic dose following a completed PK sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). In Arm 3, the EP started following last PK sampling timepoint and ended with either date of last contact or date of last entry into the eDiary, whichever was later. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. Overall units (IU/kg) of annualized rFIXFc consumption = \[Total rFIXFc IU/kg received during the EP / number of days in EP\]\*365.25.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc with evaluable data in the efficacy period. 'Overall' n=all participants in the Full Analysis Set with evaluable data in the efficacy period; 'Last 3 Months on Study' n=all participants in the Full Analysis Set with evaluable data and \>=6 months on study.

Dose normalized area under the drug concentration-time curve. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

Average dosing interval = sum of days in the included dosing intervals divided by the number of included intervals. Participants could have multiple prophylactic dose interval changes. Prophylactic dosing = from first prophylactic injection received for rFIXFc to the last prophylactic injection on study. Intervals between 2 prophylactic doses separated by a bleed/surgery/PK visit were not included. In Arm 2, the efficacy period (EP) started with date and time of first prophylactic dose following a completed PK sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). The EP was interrupted for all surgical/rehabilitation periods (for both major and minor surgeries).

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants in Arm 2 who received at least 1 dose of rFIXFc with \>=6 months on study and evaluable data.

Average weekly dose = (total IU/kg of all eligible prophylactic doses in the included intervals / total number of days in the included intervals)\*7. Eligible dose = the first of the 2 doses defining the interval. Participants could have multiple prophylactic dose changes. Prophylactic dosing = from first prophylactic injection received for rFIXFc to the last prophylactic injection on study. Intervals between 2 prophylactic doses separated by a bleed/surgery/PK visit were not included. In Arm 1, the efficacy period (EP) started with date and time of first prophylactic dose following a completed PK sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries).

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants in Arm 1 who received at least 1 dose of rFIXFc with evaluable data. 'Overall' n=participants with evaluable data; 'Last 3 Months on Study' n=participants with evaluable data and \>=6 months on study.

The measure of the efficiency of the body to remove the drug and the unit is the volume of the plasma or blood cleared of drug per unit time. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

Maximum value post-dosing is defined as maximum value over the 1-, 6-, and 24-hour evaluations.

Time frame: Pre-dose, 1 hour post-dose, 6 hours post-dose, and 24 hours post-dose at baseline (120 hours before Day 1, for BeneFIX), Day 1, Week 26, and Week 52 (for rFIXFc)

Population: The Sequential PK subgroup consisted of all participants who had evaluable PK profiles for both BeneFIX and baseline rFIXFc, and/or evaluable PK profiles for both baseline and repeat rFIXFc at Week 26 (±1 week). n=participants with an assessment at given time point.

Maximum value post-dosing is defined as maximum value over the 1-, 6-, and 24-hour evaluations.

Time frame: Pre-dose, 1 hour post-dose, 6 hours post-dose, and 24 hours post-dose at baseline (120 hours before Day 1, for BeneFIX), Day 1, Week 26, and Week 52 (for rFIXFc)

Population: The Sequential PK subgroup consisted of all participants who had evaluable PK profiles for both BeneFIX and baseline rFIXFc, and/or evaluable PK profiles for both baseline and repeat rFIXFc at Week 26 (±1 week). n=participants with an assessment at given time point.

Maximum value post-dosing is defined as maximum value over the 1-, 6-, and 24-hour evaluations.

Time frame: Pre-dose, 1 hour post-dose, 6 hours post-dose, and 24 hours post-dose at baseline (120 hours before Day 1, for BeneFIX), Day 1, Week 26, and Week 52 (for rFIXFc)

Population: The Sequential PK subgroup consisted of all participants who had evaluable PK profiles for both BeneFIX and baseline rFIXFc, and/or evaluable PK profiles for both baseline and repeat rFIXFc at Week 26 (±1 week). n=participants with an assessment at given time point.

Mean dose per injection is the average dose for all injections (including loading dose) needed to maintain hemostasis during surgery. Total dose is the sum across all injections (including loading dose) needed to maintain hemostasis during surgery.

Time frame: up to 52 weeks ± 1 week

Population: Participants in Arm 4 who received at least 1 dose of rFIXFc.

Time frame: up to 52 weeks ± 1 week

Population: Participants in Arm 4 who received at least 1 dose of rFIXFc.

The Haem-A-QoL consists of items pertaining to 10 domains specific to living with hemophilia and was administered to adult participants (\> 17 years). The areas covered by this instrument are: physical health, feeling, view of yourself, sports/leisure, school/work, dealing with hemophilia, and treatment (all 7 domains, during the last month) and future, family planning, and outlook for the future (all 3 domains, recently). Changes from baseline for the Haem-A-QoL questionnaire are summarized by prestudy treatment regimen (pooled for Arms 1 and 2). Lower scores represent better QoL; therefore, a negative change from baseline represents improvement during the course of the study. Scores on a scale range between 0 and 100.

Time frame: Baseline, Week 52

Population: Full Analysis Set: participants in the 2 prophylaxis arms (Arms 1 and 2) over 17 years of age who received at least 1 dose of rFIXFc and had an assessment. n=participants who had specified assessment at given timepoint.

Time required for the concentration of the drug to reach half of its original value. Alpha and beta half-life indicate distribution and elimination half-life in a two-compartment PK model. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

The Haem-A-QoL consists of items pertaining to 10 domains specific to living with hemophilia and was administered to adult participants (\> 17 years). The areas covered by this instrument are: physical health, feeling, view of yourself, sports/leisure, school/work, dealing with hemophilia, and treatment (all 7 domains, during the last month) and future, family planning, and outlook for the future (all 3 domains, recently). Changes from baseline for the Haem-A-QoL questionnaire are summarized by prestudy treatment regimen (pooled for Arms 1 and 2). Lower scores represent better QoL; therefore, a negative change from baseline represents improvement during the course of the study. Scores on a scale range between 0 and 100.

Time frame: Baseline, Week 26

Population: Full Analysis Set: participants in the 2 prophylaxis arms (Arms 1 and 2) over 17 years of age who received at least 1 dose of rFIXFc and had an assessment. n=participants who had specified assessment at given timepoint.

The Haemo-QoL, a quality of life (QoL) assessment instrument for children and adolescents with hemophilia, was administered to participants from 13- to 17-years-old. This instrument assesses domains specific to living with hemophilia. For the Haemo-QoL, higher scores indicate a worse quality of life. Scores on a scale range between 0 and 100.

Time frame: Baseline, Week 26, Week 52

Population: No summary analysis was done for this outcome measure due to the small number of participants completing the questionnaire.

IU/dL rise in plasma per IU/kg drug administered. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

Based on the first assessment of hemostasis by the surgeon/investigator 24 hours or later post-surgery. Scaled responses: Excellent = 1, Good = 2, Fair = 3, Poor/none = 4.

Time frame: up to 52 weeks ± 1 week

Population: Participants in Arm 4 who received at least 1 dose of rFIXFc.

Maximum concentration during a dosing interval. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

The average time for all the drug molecules to reside in the body. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

Please see the definition of the Efficacy Period (EP) in the Outcome Measure 4 Description. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A follow-up injection administered \>72 hours after the most recent injection given to treat a bleed was considered a new bleed at the same location and was classified as type=Unknown (bleeding episodes of this type were not evaluable). The first bleed for each participant could not be included in this analysis since there was no previous bleed from which to measure time. The number of days from the last injection to treat a bleed to a new bleeding episode was analyzed across all evaluable bleeding episodes per participant.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc and at least 1 evaluable bleeding episode.

In Arms 1 and 2, the efficacy period (EP) started with date and time of first prophylactic dose following a completed PK sampling period and ended with last dose administered (for prophylaxis or a bleeding episode). In Arm 3, the EP started following last PK sampling timepoint and ended with either date of last contact or date of last entry into the eDiary, whichever was later. The EP was interrupted for the repeat PK period in Arm 1 and for all surgical/rehabilitation periods in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode. All injections given from the initial sign of a bleed until the last date/time within the bleed window are counted. The resolution of a bleed is defined as no sign of bleeding following injection for the bleed.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc and had at least 1 bleeding episode.

Please see the definition of the efficacy period (EP) in the Outcome Measure 4 Description. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode. All injections given from the initial sign of a bleed until the last date/time within the bleed window were counted. The resolution of a bleed was defined as no sign of bleeding following injection for the bleed. Bleeding episodes that presented in multiple locations are included as a single event in the overall summary for the number of injections to resolve that bleeding episode but are included in summaries for each location.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc, had a bleeding episode, and had evaluable efficacy assessments; n=total number of bleeds at given location.

The number of injections to maintain hemostasis during surgery includes all injections for surgery purposes including the loading dose to the end date/time of surgery.

Time frame: up to 52 weeks ± 1 week

Population: Participants in Arm 4 who received at least 1 dose of rFIXFc.

Number of participants with clinically relevant abnormalities or relevant changes from baseline in temperature, pulse (beats per minute \[bpm\]), systolic blood pressure (SBP), and diastolic blood pressure (DBP) are presented. Baseline (BL) is defined as the last non-missing evaluable assessment taken prior and closest to the first rFIXFc dose. Because the perioperative management period represents a unique clinical situation, safety data obtained during the surgical/rehabilitation period for participants in Arm 4 were included in listings and reviewed separately. Review of the listing was sufficient to assess this endpoint.

Time frame: up to 52 weeks ± 1 week

Population: Safety Analysis Set: participants who received at least 1 dose of BeneFIX or rFIXFc; a table was not generated for participants in the perioperative management/surgical arm (Arm 4). n=participants with a baseline assessment and at least one post-baseline assessment for temperature or at least one post-baseline assessment for pulse, SBP, and DBP.

Number of blood component transfusions during a single surgery.

Time frame: up to 52 weeks ± 1 week

Population: Participants in Arm 4 who received at least 1 dose of rFIXFc.

Participant's assessment of the response to the first rFIXFc injection for each bleeding episode. Percentages were based on the number of bleeding episodes for which a response was provided for the first injection, using the following 4-point scale: excellent=abrupt pain relief and/or improvement in signs of bleeding within approximately 8 hours after the initial injection; good=definite pain relief and/or improvement in signs of bleeding within approximately 8 hours after an injection, but possibly requiring more than one injection after 24 to 48 hours for complete resolution; moderate=probable or slight beneficial effect within 8 hours after the initial injection and requiring more than one injection; no response=no improvement, or condition worsened, within approximately 8 hours after the initial injection.

Time frame: up to 52 weeks ± 1 week

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc and had a bleeding episode; participants with a non-evaluable bleeding episode are counted in the 'number of participants analyzed,' but not the percentages.

Physicians assessed each participant's response to rFIXFc using a 4-point scale: excellent=bleeding episodes responded to less than or equal to the usual number of injections or less than or equal to the usual dose of rFIXFc, or the rate of breakthrough bleeding during prophylaxis was less than or equal to that usually observed; effective=most bleeding episodes responded to the same number of injections and dose, but some required more injections or higher doses, or there was a minor increase in the rate of breakthrough bleeding; partially effective=bleeding episodes most often required more injections and/or higher doses than expected, or adequate breakthrough bleeding prevention during prophylaxis required more frequent injections and/or higher doses; ineffective=routine failure to control hemostasis or hemostatic control required additional agents. Percentage of the total count of scale responses for all participants is presented. Multiple responses per participant are counted.

Time frame: up to 52 weeks ± 1 week

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc, had evaluable efficacy assessments, and had nonmissing observations at time point.

Time to reach 1 or 3 IU/dL (%) after a single dose. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.

For each bleeding episode at one location, the total dose is the sum of the doses (IU/kg) administered across all injections given to treat that bleeding episode. Please see the definition of the efficacy period (EP) in the Outcome Measure 4 Description. The EP was interrupted for the repeat PK period in Arm 1 (sequential PK subgroup) and for all surgical/rehabilitation periods (for both major and minor surgeries) in all 3 arms. A bleeding episode started from the first sign of a bleed, and ended 72 hours after the last treatment for the bleeding, within which any symptoms of bleeding at the same location, or injections less than or equal to 72 hours apart, were considered the same bleeding episode. Bleeding episodes that presented in multiple locations are included as a single event in the overall summary for dose administered to resolve that bleeding episode but are included in the individual summaries for each location.

Time frame: up to 52 weeks ± 1 week (efficacy period as defined in description)

Population: Full Analysis Set: participants who received at least 1 dose of rFIXFc, had a bleeding episode, and had complete information on the dose administered to treat a bleeding episode; n=total number of bleeding episodes at this location.

Volume of distribution at steady state. Assessment of FIX activity with BeneFIX was conducted following a required 120-hour (5-day) washout period, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 72 (±3) hours, and 96 (±3) hours (4 days) from the start of the injection. Assessment of FIX activity and rFIXFc concentration was conducted following the initial dose of rFIXFc (after a required 120-hour \[5-day\] washout period) and at Week 26, at these timepoints: predose, 10 (±2) minutes, 1 hour (±15 minutes), 3 hours (±15 minutes), 6 hours (±15 minutes), 24 (±2) hours, 48 (±2) hours, 96 (±3) hours (4 days), 144 (±3) hours (6 days), 168 (±3) hours (7 days), 192 (±3) hours (8 days), and 240 (±3) hours (10 days) from the start of the injection.

Time frame: See Measure Description for complete time frame. Each participant was to complete PK sampling up to, and including, the 96-hour (4-day) timepoint for BeneFIX PK assessment and the 240-hour (10-day) timepoint for rFIXFc PK assessment.

Population: Participants in the Sequential PK Subgroup who have evaluable PK profiles for both BeneFIX and baseline rFIXFc.