Model-Based Annualized Bleed Rate (ABR) for All Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of all bleeds over the efficacy period was assessed as an annualized bleed rate (ABR) using a negative binomial (NB) regression model, which accounts for different follow-up times. All bleeds included both treated bleeds (with coagulation factors) and non-treated bleeds. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Intra-Participant Comparison of the Model-Based Annualized Bleed Rate (ABR) for All Bleeds in Arm A: Emicizumab Versus Previous Episodic Bypassing Agents
This was an intra-participant comparison of the annualized bleed rates (ABRs) for all bleeds in Arm A participants who had previously received episodic bypassing agents during the non-interventional study (NIS) BH29768 (NCT02476942) (Arm A NIS) prior to entry in this study versus emicizumab prophylaxis during this study (Arm A). The number of all bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. All bleeds included both treated bleeds (with coagulation factors) and non-treated bleeds. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Intra-Participant Comparison of the Model-Based Annualized Bleed Rate (ABR) for Treated Bleeds in Arm A: Emicizumab Versus Previous Episodic Bypassing Agents
This was an intra-participant comparison of the ABRs for treated bleeds in Arm A participants who had previously received episodic bypassing agents during the non-interventional study (NIS) BH29768 (NCT02476942) (Arm A NIS) prior to entry in this study versus emicizumab prophylaxis during this study (Arm A). The number of treated bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated bleeds were defined as a bleed that was directly followed by a hemophilia medication reported to be a "treatment for bleed". The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, efficacy period ended the day before the first day on the up-titrated dose.
Model-Based Annualized Bleed Rate (ABR) for Treated Joint Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of treated joint bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated joint bleeds were defined as treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Bleeds due to surgery/procedure were excluded.
Intra-Participant Comparison of the Model-Based Annualized Bleed Rate (ABR) for All Bleeds in Arm C: Emicizumab Versus Previous Prophylactic Bypassing Agents
This was an intra-participant comparison of the annualized bleed rates (ABRs) for all bleeds in Arm C participants who had previously received prophylactic bypassing agents during the non-interventional study (NIS) BH29768 (NCT02476942) (Arm C NIS) prior to entry in this study versus emicizumab prophylaxis during this study (Arm C). The number of all bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. All bleeds included both treated bleeds (with coagulation factors) and non-treated bleeds. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Intra-Participant Comparison of the Model-Based Annualized Bleed Rate (ABR) for Treated Bleeds in Arm C: Emicizumab Versus Previous Prophylactic Bypassing Agents
This was an intra-participant comparison of the ABRs for treated bleeds in Arm C participants who had previously received bypassing agent prophylaxis during the non-interventional study (NIS) BH29768 (NCT02476942) (Arm C NIS) prior to entry in this study versus emicizumab prophylaxis during this study (Arm C). The number of treated bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated bleeds were defined as a bleed that was directly followed by a hemophilia medication reported to be a "treatment for bleed". The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, efficacy period ended the day before the first day on the up-titrated dose.
Model-Based Annualized Bleed Rate (ABR) for Treated Spontaneous Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of treated spontaneous bleeds over the efficacy period was assessed as an annualized bleed rate (ABR) using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated spontaneous bleeds were defined as treated (with coagulation factors) bleeds with no known contributing factor (e.g., trauma, surgery). The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Model-Based Annualized Bleed Rate (ABR) for Treated Target Joint Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of treated target joint bleeds over the efficacy period was assessed as an annualized bleed rate (ABR) using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated target joint bleeds included treated (with coagulation factors) joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Mean Calculated Annualized Bleed Rates (ABR) for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Median Calculated Annualized Bleed Rates (ABR) for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
The number of bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Percentage of Participants With 0 Bleeds for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, Arm A: Emicizumab Versus Arm B: No Prophylaxis
Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Hemophilia-Specific Quality of Life (Haem-A-QoL) Questionnaire Physical Health Score at Week 25 in Adult Participants (>/=18 Years Old), Arm A: Emicizumab Versus Arm B: No Prophylaxis
Haem-A-QoL questionnaire has been developed and used in hemophilia A participants. As a hemophilia-specific questionnaire, this measure assesses very specific aspects of dealing with hemophilia. This questionnaire consists of items pertaining to 10 domains specific to living with hemophilia. The 10 domains are: physical health, sports and leisure, school and work, dealing with hemophilia, family planning, feeling, relationships, treatment, view of yourself, and outlook for the future. The total score for each domain range from 0 to 100 with lower scores reflective of better quality of life. Physical Health domain score is reported (range 0 to 100, with lower scores reflective of better physical health).
Haem-A-QoL Questionnaire Total Score at Week 25 in Adult Participants (>/=18 Years Old), Arm A: Emicizumab Versus Arm B: No Prophylaxis
Haem-A-QoL questionnaire has been developed and used in hemophilia A participants. As a hemophilia-specific questionnaire, this measure assesses very specific aspects of dealing with hemophilia. This questionnaire consists of items pertaining to 10 domains specific to living with hemophilia. The 10 domains are: physical health, sports and leisure, school and work, dealing with hemophilia, family planning, feeling, relationships, treatment, view of yourself, and outlook for the future. The total score for each domain range from 0 to 100 with lower scores reflective of better quality of life. Haem-A-QoL Questionnaire Total Score is the average of the all domain scores and range from 0 to 100, with lower scores reflective of better quality of life.
European Quality of Life-5 Dimensions-5 Levels (EQ-5D-5L) Visual Analog Scale Score at Week 25, Arm A: Emicizumab Versus Arm B: No Prophylaxis
EQ-5D-5L is a standardized, participant-rated questionnaire to assess health-related quality of life. The EQ-5D-5L includes 2 components: the EQ-5D-5L health state profile (descriptive system) and the EQ-5D-5L Visual Analog Scale. The Visual Analogue Scale is designed to rate the participant's current health state on a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state.
EQ-5D-5L Index Utility Score at Week 25, Arm A: Emicizumab Versus Arm B: No Prophylaxis
EQ-5D-5L is a standardized, participant-rated questionnaire to assess health-related quality of life. The EQ-5D-5L includes 2 components: the EQ-5D-5L health state profile (descriptive system) and the EQ-5D-5L Visual Analog Scale. The EQ-5D-5L health state profile is designed to record the participant's current health state in 5 domains: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Responses from the five domains are used to calculate a single utility index value ranging from 1 to 5, where 1 indicates better health state (no problems) and 5 indicates worst health state (confined to bed).
Hemophilia-Specific Quality of Life - Short Form (Haemo-Qol-SF) Questionnaire Total Score at Baseline and Week 25 in Adolescent Participants (12-17 Years Old)
The Haemo-QoL-SF contains 35 items, which cover nine domains considered relevant for the children's health-related quality of life (physical health, feelings, view of yourself, family, friends, other people, sports and school, dealing with hemophilia and treatment). Items are rated with five respective response options: never, seldom, sometimes, often, and always. Haemo-QoL-SF total score range from 0 to 100, where lower scores reflect better health-related quality of life. Baseline was defined as the last assessment prior to treatment. Because participants in Arm B switched from episodic bypassing agents to start receiving emicizumab prophylaxis after Week 24, the timepoints for Arm B (Emi) are expressed relative to first emicizumab dose; baseline for Arm B (Emi) is the same as Week 25 for Arm B (Control).
Long-Term Efficacy of Emicizumab: Model-Based Annualized Bleed Rates (ABR) for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, All Enrolled Participants
The number of bleeds over the efficacy period was assessed as an ABR using a negative binomial (NB) regression model, which accounts for different follow-up times. Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Long-Term Efficacy of Emicizumab: Mean Calculated Annualized Bleed Rates (ABR) for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, All Enrolled Participants
The number of bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Long-Term Efficacy of Emicizumab: Median Calculated Annualized Bleed Rates (ABR) for Treated Bleeds, All Bleeds, Treated Spontaneous Bleeds, Treated Joint Bleeds, and Treated Target Joint Bleeds, All Enrolled Participants
The number of bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. All bleeds included both treated and non-treated bleeds. Treated spontaneous bleeds: treated bleeds with no known contributing factor (e.g., trauma, surgery). Treated joint bleeds: treated bleeds in a joint associated with unusual sensation (aura) in a joint, in combination with another symptom: swelling/warmth, pain/decreased range of motion (RoM), or difficulty moving the joint. Treated target joint bleeds: treated joint bleeds in a target joint, defined as a joint in which greater than or equal to (>/=) 3 treated joint bleeds occurred during the last 24 weeks prior to study entry. For all types of bleeds: the 72-hour rule was implemented, and bleeds due to surgery/procedure and bleeds after up-titration were excluded.
Long-Term Efficacy of Emicizumab: Mean Calculated Annualized Bleed Rates (ABR) for Treated Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of treated bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Long-Term Efficacy of Emicizumab: Median Calculated Annualized Bleed Rates (ABR) for Treated Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of treated bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated bleeds: a bleed for which coagulation factors were administered. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Long-Term Efficacy of Emicizumab: Mean Calculated Annualized Bleed Rates (ABR) for All Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of all bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. All bleeds included both treated bleeds (with coagulation factors) and non-treated bleeds. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Long-Term Efficacy of Emicizumab: Median Calculated Annualized Bleed Rates (ABR) for All Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of all bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. All bleeds included both treated bleeds (with coagulation factors) and non-treated bleeds. The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Long-Term Efficacy of Emicizumab: Mean Calculated Annualized Bleed Rates (ABR) for Treated Spontaneous Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of treated spontaneous bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated spontaneous bleeds were defined as treated (with coagulation factors) bleeds with no known contributing factor (e.g., trauma, surgery). The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Long-Term Efficacy of Emicizumab: Median Calculated Annualized Bleed Rates (ABR) for Treated Spontaneous Bleeds Per 12-Week Intervals Over Time, All Enrolled Participants
The number of treated spontaneous bleeds over the efficacy period was calculated as: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. Treated spontaneous bleeds were defined as treated (with coagulation factors) bleeds with no known contributing factor (e.g., trauma, surgery). The 72-hour rule was implemented: two bleeds of the same type and at the same anatomical location were counted as one bleed if the second bleed occurred within 72 hours from the last treatment for the first bleed. Bleeds due to surgery/procedure were excluded. For participants whose dose was up-titrated, the efficacy period ended the day before the first day on the up-titrated dose.
Safety Summary of the Overall Number and Percentage of Participants With at Least One Adverse Event, Severity Assessed According to the WHO Toxicity Grading Scale
Investigators sought information on adverse events (AEs) at each contact with participants. The WHO toxicity grading scale was used for assessing AE severity (i.e., intensity of an AE); any AEs not specifically listed in the WHO toxicity grading scale were assessed for severity according to the following grades: Grade 1 is mild; Grade 2 is moderate, Grade 3 is severe; Grade 4 is life-threatening; and Grade 5 is death. Regardless of severity, some AEs may have also met seriousness criteria. The terms "severe" and "serious" are not synonymous; severity and seriousness were independently assessed for each AE. For participants whose emicizumab dose was up-titrated, only data before up-titration is included. aPCC = activated prothrombin complex concentrate; Hypersens.= hypersensitivity
Number of Participants Testing Negative or Positive for the Presence of Anti-Drug Antibodies (ADAs), Including Neutralizing ADAs, During the Study
'Total ADA Negative' is the sum of all subjects who tested negative for ADA in the 2 following categories: 'ADA Negative', those who are pre-dose ADA negative or are missing pre-dose ADA data and who have all negative post-dose ADA results; and 'ADA Negative (Treatment Unaffected)', a subset who are pre-dose ADA positive but do not have a ≥4-fold increase in post-dose ADA levels compared to baseline measurement. 'Total ADA Positive' is the sum of all subjects who tested positive for ADA in the 2 following categories: 'ADA Positive (Treatment Boosted)', those who are pre-dose ADA positive and have a ≥4-fold increase in post-dose ADA levels compared to baseline measurement; and 'ADA Positive (Treatment Induced)', those who are pre-dose ADA negative or missing data and who have at least one post-dose ADA positive sample. ADA-positive samples were further analyzed for neutralizing capacity using a modified FVIII chromogenic assay; if also positive, they were considered neutralizing ADAs.
Plasma Trough Concentrations of Emicizumab at Specified Timepoints
Plasma concentrations of emicizumab were analyzed using a validated Enzyme Linked Immunosorbent Assay (ELISA). The lower limit of quantification (LLOQ) was 100 nanograms per milliliter (ng/mL). Because participants in Arm B switched from episodic bypassing agents to start receiving emicizumab prophylaxis after Week 24, the timepoints for Arm B (Emi) are expressed relative to first emicizumab dose.