Trial Outcomes & Findings for A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Subcutaneous Emicizumab in Participants From Birth to 12 Months of Age With Hemophilia A Without Inhibitors (NCT NCT04431726)

NCT ID: NCT04431726

Last Updated: 2026-01-29

Results Overview

The number of treated bleeds over the efficacy period was estimated as an annualized bleeding rate (ABR) using a negative binomial regression model, which accounts for different follow-up times. A treated bleed was 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.

• Recruitment status: ACTIVE_NOT_RECRUITING
• Study phase: PHASE3
• Target enrollment: 55 participants
• Primary outcome timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)
• Results posted on: 2026-01-29

Participant Flow

Overall, 55 participants were enrolled in the study.

Participant milestones

Measure	Emicizumab Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Overall Study STARTED	55
Overall Study Received at Least One Dose of Study Drug	55
Overall Study Completed 52 Weeks in the Study	55
Overall Study Started the Long-Term Follow-Up Period	55
Overall Study COMPLETED	0
Overall Study NOT COMPLETED	55

Reasons for withdrawal

Measure

Emicizumab Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Overall Study Ongoing in the Study

55

Baseline Characteristics

A Study to Evaluate the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Subcutaneous Emicizumab in Participants From Birth to 12 Months of Age With Hemophilia A Without Inhibitors

Baseline characteristics by cohort

Measure	Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Age, Continuous	5.0 Months STANDARD_DEVIATION 3.9 • n=35 Participants
Sex: Female, Male Female	0 Participants n=35 Participants
Sex: Female, Male Male	55 Participants n=35 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	5 Participants n=35 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	49 Participants n=35 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=35 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=35 Participants
Race (NIH/OMB) Asian	3 Participants n=35 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=35 Participants
Race (NIH/OMB) Black or African American	1 Participants n=35 Participants
Race (NIH/OMB) White	48 Participants n=35 Participants
Race (NIH/OMB) More than one race	0 Participants n=35 Participants
Race (NIH/OMB) Unknown or Not Reported	2 Participants n=35 Participants

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated bleeds over the efficacy period was estimated as an annualized bleeding rate (ABR) using a negative binomial regression model, which accounts for different follow-up times. A treated bleed was 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Model-Based Annualized Bleeding Rate for Treated Bleeds

0.4 Treated bleeds per year Interval 0.3 to 0.63

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated bleed was 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Mean Calculated Annualized Bleeding Rate for Treated Bleeds

0.5 Treated bleeds per year Interval 0.0 to 4.59

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated bleed was 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Median Calculated Annualized Bleeding Rate for Treated Bleeds

0.0 Treated bleeds per year Interval 0.0 to 0.81

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of all bleeds over the efficacy period was estimated as an annualized bleeding rate (ABR) using a negative binomial regression model, which accounts for different follow-up times. In this outcome measure, all bleeds are included, irrespective of treatment with coagulation factors, with the following exception: bleeds due to surgery/procedure are excluded. As "all bleeds" comprises both treated and non-treated bleeds, the 72-hour rule was implemented separately for treated and non-treated bleeds. For treated bleeds, the 72-hour rule meant that 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. For non-treated bleeds, the 72-hour rule was implemented by calculating a treatment-free period of 72 hours from the bleed itself.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Model-Based Annualized Bleeding Rate for All Bleeds

2.0 All bleeds per year Interval 1.49 to 2.66

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of all bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. In this outcome measure, all bleeds are included, irrespective of treatment with coagulation factors, with the following exception: bleeds due to surgery/procedure are excluded. As "all bleeds" comprises both treated and non-treated bleeds, the 72-hour rule was implemented separately for treated and non-treated bleeds. For treated bleeds, the 72-hour rule meant that 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. For non-treated bleeds, the 72-hour rule was implemented by calculating a treatment-free period of 72 hours from the bleed itself.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Mean Calculated Annualized Bleeding Rate for All Bleeds

2.0 All bleeds per year Interval 0.24 to 7.22

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of all bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. In this outcome measure, all bleeds are included, irrespective of treatment with coagulation factors, with the following exception: bleeds due to surgery/procedure are excluded. As "all bleeds" comprises both treated and non-treated bleeds, the 72-hour rule was implemented separately for treated and non-treated bleeds. For treated bleeds, the 72-hour rule meant that 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. For non-treated bleeds, the 72-hour rule was implemented by calculating a treatment-free period of 72 hours from the bleed itself.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Median Calculated Annualized Bleeding Rate for All Bleeds

1.0 All bleeds per year Interval 0.53 to 2.93

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated spontaneous bleeds over the efficacy period was estimated as an annualized bleeding rate (ABR) using a negative binomial regression model, which accounts for different follow-up times. A treated spontaneous bleed was defined as a treated bleed (bleed directly followed by a hemophilia medication reported to be a "treatment for bleed") with no other known contributing factor such as trauma or procedure/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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Model-Based Annualized Bleeding Rate for Treated Spontaneous Bleeds

NA Treated spontaneous bleeds per year No participants experienced treated spontaneous bleeds while receiving emicizumab prophylaxis up to the clinical cutoff date; thus, the ABR and 95% confidence interval could not be estimated using the model-based approach.

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated spontaneous bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated spontaneous bleed was defined as a treated bleed (bleed directly followed by a hemophilia medication reported to be a "treatment for bleed") with no other known contributing factor such as trauma or procedure/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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Mean Calculated Annualized Bleeding Rate for Treated Spontaneous Bleeds

0.0 Treated spontaneous bleeds per year Interval to 3.69 The lower limit of the 95% confidence interval could not be calculated because no participants experienced treated spontaneous bleeds up to the clinical cutoff date.

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated spontaneous bleeds over the efficacy period is presented here as a calculated annualized bleeding rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated spontaneous bleed was defined as a treated bleed (bleed directly followed by a hemophilia medication reported to be a "treatment for bleed") with no other known contributing factor such as trauma or procedure/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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Median Calculated Annualized Bleeding Rate for Treated Spontaneous Bleeds

0.0 Treated spontaneous bleeds per year Interval 0.0 to 0.0

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated joint bleeds over the efficacy period was estimated as an annualized bleed rate (ABR) using a negative binomial regression model, which accounts for different follow-up times. A treated joint bleed was defined as a bleed with type reported as "joint" based on at least one of the following symptoms: increasing swelling or warmth of the skin over the joint and/or increasing pain, decreased range of motion, or difficulty using the joint compared with baseline, and the bleed 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Model-Based Annualized Bleeding Rate for Treated Joint Bleeds

0.0 Treated joint bleeds per year Interval 0.0 to 0.1

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated joint bleeds over the efficacy period is presented here as a calculated annualized bleed rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated joint bleed was defined as a bleed with type reported as "joint" based on at least one of the following symptoms: increasing swelling or warmth of the skin over the joint and/or increasing pain, decreased range of motion, or difficulty using the joint compared with baseline, and the bleed 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Mean Calculated Annualized Bleeding Rate for Treated Joint Bleeds

0.0 Treated joint bleeds per year Interval 0.0 to 3.75

PRIMARY outcome

Timeframe: From first dose of emicizumab to the clinical cutoff date or withdrawal date, whichever was earlier (median [range, min-max] efficacy period: 101.9 [52.6-119.7] weeks)

Population: The Treated Population includes all participants who received at least one dose of emicizumab.

The number of treated joint bleeds over the efficacy period is presented here as a calculated annualized bleed rate (ABR) that was annualized for each participant using the following formula: ABR = (number of bleeds/number of days during the efficacy period) x 365.25. A treated joint bleed was defined as a bleed with type reported as "joint" based on at least one of the following symptoms: increasing swelling or warmth of the skin over the joint and/or increasing pain, decreased range of motion, or difficulty using the joint compared with baseline, and the bleed 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.

Outcome measures

Measure

Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.

Median Calculated Annualized Bleeding Rate for Treated Joint Bleeds

0.0 Treated joint bleeds per year Interval 0.0 to 0.0

SECONDARY outcome

Timeframe: At Years 4, 5, 6, 7, and 8 of follow-up

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: At Years 5 and 8 of follow-up

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: From first dose of emicizumab until study completion (8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, Weeks 4, 13, 21, 29, 37, 45, and 53

Population: The Safety-Evaluable Population includes all participants who received at least one dose of emicizumab. The number analyzed (denominator) represents the total number of participants according to their baseline test result WHO toxicity grade for each parameter.

Laboratory parameters for hematology and blood chemistry were measured at baseline and over time, and the values were compared with a standard reference range. Values outside the standard reference range were considered laboratory abnormalities and graded according to the World Health Organization (WHO) toxicity grading scale, ranging from lowest (Grade 1) to greatest (Grade 4) deviation from standard in the direction indicated for the abnormality (i.e., below (Low) or above (High) the reference range; 'Not Low' and 'Not High' indicate values within the reference range). Participants were categorized according to their laboratory test result shift from baseline WHO grade to highest WHO grade at any point post-baseline (up to Week 53) for each parameter. 'Missing' indicates that the test result was not available.

Outcome measures

Measure	Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Not High to Not High	43 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Not High to Not High	31 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (Low), Missing to Not Low	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Not Low to Not Low	36 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Not Low to Grade 1	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Not Low to Grade 2	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Grade 1 to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Grade 1 to Grade 1	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Grade 1 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Grade 1 to Grade 4	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Hemoglobin (Low), Grade 2 to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Not Low to Not Low	8 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Not Low to Grade 1	14 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Not Low to Grade 2	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Not Low to Grade 3	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Not Low to Grade 4	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 1 to Not Low	4 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 1 to Grade 1	7 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 1 to Grade 2	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 1 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 2 to Not Low	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 2 to Grade 1	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 2 to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Grade 2 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Missing to Not Low	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Missing to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Neutrophils, Total, Abs. (Low), Missing to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Platelets (Low), Not Low to Not Low	54 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Platelets (Low), Not Low to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Not High to Not High	32 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Not High to Grade 1	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Not High to Grade 2	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Not High to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Not High to Grade 4	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 1 to Not High	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 1 to Grade 1	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 1 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 2 to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 2 to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Grade 2 to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Missing to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Alkaline Phosphatase (High), Missing to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Not High to Grade 1	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Not High to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Not High to Grade 4	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Grade 1 to Grade 1	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Grade 1 to Grade 4	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGPT/ALT (High), Missing to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Not High to Grade 1	11 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Not High to Grade 3	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Grade 1 to Not High	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Grade 1 to Grade 1	8 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline SGOT/AST (High), Grade 1 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Blood Urea Nitrogen (High), Not High to Not High	42 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Blood Urea Nitrogen (High), Not High to Grade 1	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Blood Urea Nitrogen (High), Grade 1 to Grade 1	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Blood Urea Nitrogen (High), Missing to Not High	4 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Not High to Not High	13 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Not High to Grade 1	18 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Grade 1 to Not High	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Grade 1 to Grade 1	17 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Grade 1 to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Grade 2 to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (High), Missing to Not High	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Not High to Not High	32 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Not High to Grade 1	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Grade 1 to Not High	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Grade 1 to Grade 1	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Missing to Not High	5 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (High), Missing to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Creatinine (High), Not High to Not High	53 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Creatinine (High), Not High to Grade 1	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (High), Not High to Not High	51 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (High), Not High to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (High), Missing to Not High	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Not High to Not High	40 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Not High to Grade 1	7 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Grade 1 to Not High	4 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Grade 1 to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Missing to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Missing to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Potassium (High), Missing to Grade 3	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (High), Not High to Not High	52 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (High), Grade 1 to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (High), Missing to Not High	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Not High to Not High	43 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Not High to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 1 to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 2 to Not High	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 3 to Not High	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 3 to Grade 1	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 4 to Not High	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 4 to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Bilirubin (High), Grade 4 to Grade 3	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (Low), Not Low to Not Low	50 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (Low), Not Low to Grade 4	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium (Low), Missing to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (Low), Not Low to Not Low	47 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Calcium, Corrected for Albumin (Low), Not Low to Grade 4	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (Low), Not Low to Not Low	44 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (Low), Not Low to Grade 1	6 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (Low), Not Low to Grade 2	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (Low), Grade 1 to Not Low	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Glucose (Low), Missing to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Magnesium (Low), Not Low to Not Low	50 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Magnesium (Low), Grade 1 to Not Low	2 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Magnesium (Low), Missing to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Phosphorus (Low), Not Low to Not Low	52 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Phosphorus (Low), Missing to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Postassium (Low), Not Low to Not Low	52 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Postassium (Low), Missing to Not Low	3 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Not Low to Not Low	35 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Not Low to Grade 1	13 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Grade 1 to Not Low	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Grade 1 to Grade 1	4 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Missing to Not Low	1 Participants
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline Sodium (Low), Missing to Grade 1	1 Participants

SECONDARY outcome

Timeframe: Baseline, Weeks 1, 2, 3, 4, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53, and annually during the 7-year follow-up period until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, Weeks 1, 2, 3, 4, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53, and annually during the 7-year follow-up period until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, Weeks 1, 2, 3, 4, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53, and annually during the 7-year follow-up period until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, Weeks 1, 2, 3, 4, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53, and annually during the 7-year follow-up period until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, Weeks 1, 2, 3, 4, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53, and annually during the 7-year follow-up period until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Predose at Weeks 1, 3, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53

Population: The Pharmacokinetic (PK)-Evaluable Population: includes all participants who had received at least one dose of emicizumab and had at least one post-baseline emicizumab plasma concentration result. The number analyzed indicates the number of participants who provided a PK sample at a given timepoint.

Outcome measures

Measure	Emicizumab n=55 Participants Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 1	NA micrograms per millilitre (μg/mL) Standard Deviation NA The mean and standard deviation could not be calculated because all samples were below the limit of quantitation. The samples were taken prior to administration of the first dose.
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 3	36.8 micrograms per millilitre (μg/mL) Standard Deviation 9.8
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 5	62.0 micrograms per millilitre (μg/mL) Standard Deviation 13.4
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 7	62.3 micrograms per millilitre (μg/mL) Standard Deviation 13.5
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 9	64.2 micrograms per millilitre (μg/mL) Standard Deviation 14.4
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 13	66.0 micrograms per millilitre (μg/mL) Standard Deviation 12.0
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 17	65.8 micrograms per millilitre (μg/mL) Standard Deviation 13.1
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 21	65.8 micrograms per millilitre (μg/mL) Standard Deviation 13.9
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 25	65.6 micrograms per millilitre (μg/mL) Standard Deviation 15.1
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 29	63.2 micrograms per millilitre (μg/mL) Standard Deviation 14.6
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 33	64.0 micrograms per millilitre (μg/mL) Standard Deviation 21.5
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 37	63.1 micrograms per millilitre (μg/mL) Standard Deviation 15.8
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 41	62.0 micrograms per millilitre (μg/mL) Standard Deviation 17.6
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 45	59.9 micrograms per millilitre (μg/mL) Standard Deviation 16.6
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 49	57.1 micrograms per millilitre (μg/mL) Standard Deviation 14.7
Plasma Trough Concentrations (Ctrough) of Emicizumab Week 53	56.8 micrograms per millilitre (μg/mL) Standard Deviation 15.3

SECONDARY outcome

Timeframe: Weeks 1, 5, 17, 29, 41, and 53, and thereafter as clinically indicated until study completion (up to 8 years)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: As clinically indicated from baseline until study completion (up to 8 years)

As per the protocol, after any 3 exposure days to FVIII or a block of FVIII exposure days (e.g., a block is defined as a minimum of two consecutive doses of FVIII) administered for treatment of a bleed, a surgical procedure, or other (e.g., preventative doses before activity), one plasma sample for anti-FVIII antibodies (for centralized analysis) had to be collected 14 days after the final dose of FVIII administered.

Outcome measures

Outcome data not reported

Adverse Events

Emicizumab

Serious events: 16 serious events

Other events: 54 other events

Deaths: 0 deaths

Serious adverse events

Measure	Emicizumab n=55 participants at risk Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Infections and infestations Bronchiolitis	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Bronchitis	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Pneumonia	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Tonsillitis	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Ear infection	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Laryngitis	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Upper respiratory tract infection	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Urinary tract infection	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Viral infection	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Fall	7.3% 4/55 • Number of events 4 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Head injury	5.5% 3/55 • Number of events 4 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Eyelid contusion	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Post procedural fever	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Post procedural haemorrhage	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Skin laceration	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Tongue injury	1.8% 1/55 • Number of events 1 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Mouth haemorrhage	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Tongue haemorrhage	3.6% 2/55 • Number of events 2 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.

Other adverse events

Measure	Emicizumab n=55 participants at risk Initially, all participants received loading doses of 3 milligrams per kilogram (mg/kg) emicizumab subcutaneously (SC) once every week (QW) for 4 weeks followed by the maintenance dosing regimen 3 mg/kg emicizumab SC once every 2 weeks (Q2W) for a total of 52 weeks. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers could have elected for their child to continue with the maintenance 3-mg/kg SC Q2W dosing regimen or to switch to the maintenance 1.5-mg/kg SC QW or 6-mg/kg SC once every 4 weeks (Q4W) dosing regimen for the subsequent 7-year long-term follow-up period.
Blood and lymphatic system disorders Neutropenia	5.5% 3/55 • Number of events 4 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Diarrhoea	21.8% 12/55 • Number of events 14 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Teething	14.5% 8/55 • Number of events 12 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Vomiting	14.5% 8/55 • Number of events 11 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Gastrointestinal disorders Constipation	5.5% 3/55 • Number of events 3 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
General disorders Pyrexia	47.3% 26/55 • Number of events 51 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
General disorders Injection site reaction	20.0% 11/55 • Number of events 32 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
General disorders Hyperpyrexia	9.1% 5/55 • Number of events 7 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Upper respiratory tract infection	40.0% 22/55 • Number of events 57 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Nasopharyngitis	32.7% 18/55 • Number of events 39 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations COVID-19	29.1% 16/55 • Number of events 16 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Bronchitis	14.5% 8/55 • Number of events 8 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Ear infection	12.7% 7/55 • Number of events 15 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Gastroenteritis	14.5% 8/55 • Number of events 12 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Conjunctivitis	12.7% 7/55 • Number of events 10 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Viral upper respiratory tract infection	12.7% 7/55 • Number of events 16 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Viral infection	9.1% 5/55 • Number of events 10 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Hand-foot-and-mouth disease	9.1% 5/55 • Number of events 5 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Gastroenteritis viral	7.3% 4/55 • Number of events 5 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Otitis media	7.3% 4/55 • Number of events 5 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Gastrointestinal infection	5.5% 3/55 • Number of events 3 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Infections and infestations Varicella	5.5% 3/55 • Number of events 3 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Fall	29.1% 16/55 • Number of events 32 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Injury, poisoning and procedural complications Head injury	18.2% 10/55 • Number of events 18 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Skin and subcutaneous tissue disorders Rash	18.2% 10/55 • Number of events 11 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Skin and subcutaneous tissue disorders Dermatitis diaper	7.3% 4/55 • Number of events 5 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Respiratory, thoracic and mediastinal disorders Cough	23.6% 13/55 • Number of events 20 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Respiratory, thoracic and mediastinal disorders Rhinorrhea	10.9% 6/55 • Number of events 13 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Respiratory, thoracic and mediastinal disorders Nasal congestion	9.1% 5/55 • Number of events 5 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Investigations Blood alkaline phosphatase increased	5.5% 3/55 • Number of events 4 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.
Metabolism and nutrition disorders Iron deficiency	10.9% 6/55 • Number of events 6 • From first dose of emicizumab until the primary completion date cutoff (median [range, min-max] observation period: 101.9 [52.6-119.7] weeks) Adverse events (AEs) are reported in the Safety-Evaluable/Treated Population, comprising all participants who received at least one dose of emicizumab. AEs are still being collected until the end of the study and the results will be updated within 1 year of the date of final data collection.

Additional Information

Medical Communications

Hoffmann-La Roche

Phone: 800-821-8590

Email: genentech@druginfo.com

Results disclosure agreements

• Principal investigator is a sponsor employee The Study being conducted under this Agreement is part of the Overall Study. Investigator is free to publish in reputable journals or to present at professional conferences the results of the Study, but only after the first publication or presentation that involves the Overall Study. The Sponsor may request that Confidential Information be deleted and/or the publication be postponed in order to protect the Sponsor's intellectual property rights.
• Publication restrictions are in place

Restriction type: OTHER