This is a Phase IIIb, multicenter, open-label, single-arm study of prophylactic emicizumab in previously untreated and minimally treated patients at study enrollment from birth to ≤12 months of age with severe hemophilia A (intrinsic factor VIII \[FVIII\] level \<1%) without FVIII inhibitors. The study is designed to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of emicizumab administered at 3 milligrams per kilogram of body weight (mg/kg) once every 2 weeks (Q2W) for 52 weeks. After 1 year of treatment, participants will continue to receive emicizumab (1.5 mg/kg once every week \[QW\], 3 mg/kg Q2W or 6 mg/kg once every 4 weeks \[Q4W\]) over a 7-year long-term follow-up period under this study frame.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
55
Initially, all participants will receive 4 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. Starting from Week 17 of treatment, individual participants may have their dose up-titrated to 3 mg/kg SC QW if they experience suboptimal bleeding control. At the Week 53 clinic visit following consultation with the treating physician, parents/caregivers may elect 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. During the study, participants will be treated with emicizumab until unacceptable toxicity, discontinuation from the study due to any cause, or other criteria specified in the protocol, whichever occurs first.
Phoenix Children's Hospital
Phoenix, Arizona, United States
Children's Hospital Los Angeles
Los Angeles, California, United States
University of Colorado Denver, Children's Hospital
Aurora, Colorado, United States
Tulane University Health Sciences Center
New Orleans, Louisiana, United States
University of Michigan
Ann Arbor, Michigan, United States
Model-Based Annualized Bleeding Rate for Treated Bleeds
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.
Time frame: 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)
Mean Calculated Annualized Bleeding Rate for Treated Bleeds
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.
Time frame: 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)
Median Calculated Annualized Bleeding Rate for Treated Bleeds
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.
Time frame: 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)
Model-Based Annualized Bleeding Rate for All Bleeds
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.
Time frame: 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)
Mean Calculated Annualized Bleeding Rate for All Bleeds
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.
Time frame: 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)
Median Calculated Annualized Bleeding Rate for All Bleeds
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.
Time frame: 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)
Model-Based Annualized Bleeding Rate for Treated Spontaneous Bleeds
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.
Time frame: 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)
Mean Calculated Annualized Bleeding Rate for Treated Spontaneous Bleeds
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.
Time frame: 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)
Median Calculated Annualized Bleeding Rate for Treated Spontaneous Bleeds
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.
Time frame: 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)
Model-Based Annualized Bleeding Rate for Treated Joint Bleeds
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.
Time frame: 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)
Mean Calculated Annualized Bleeding Rate for Treated Joint Bleeds
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.
Time frame: 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)
Median Calculated Annualized Bleeding Rate for Treated Joint Bleeds
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.
Time frame: 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)
Hemophilia Joint Health Score (HJHS) Total Score at Specified Timepoints During the Long-Term Follow-Up Period
Time frame: At Years 4, 5, 6, 7, and 8 of follow-up
Magnetic Resonance Imaging (MRI) Score of Specific Joints at Specified Timepoints During the Long-Term Follow-Up Period
Time frame: At Years 5 and 8 of follow-up
Incidence and Severity of Adverse Events, With Severity Determined According to World Health Organization (WHO) Toxicity Grading Scale
Time frame: From first dose of emicizumab until study completion (8 years)
Incidence of Thromboembolic Events
Time frame: From first dose of emicizumab until study completion (8 years)
Incidence of Thrombotic Microangiopathy
Time frame: From first dose of emicizumab until study completion (8 years)
Incidence and Severity of of Injection Site Reactions, With Severity Determined According to WHO Toxicity Grading Scale
Time frame: From first dose of emicizumab until study completion (8 years)
Incidence of Severe Hypersensitivity, Anaphylaxis, and Anaphylactoid Events
Time frame: From first dose of emicizumab until study completion (8 years)
Incidence of Adverse Events Leading to Study Drug Discontinuation
Time frame: From first dose of emicizumab until study completion (8 years)
Number of Participants According to Hematology and Serum Chemistry Laboratory Test Result Shifts From Baseline WHO Grade to the Highest WHO Grade Post-Baseline
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.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Seattle Children's Hospital
Seattle, Washington, United States
The Children's Hospital at Westmead
Westmead, New South Wales, Australia
Royal Children's Hospital
Parkville, Victoria, Australia
Perth Children's Hospital
Nedlands, Western Australia, Australia
Medizinische Universität Wien
Vienna, Austria
...and 22 more locations
Time frame: Baseline, Weeks 4, 13, 21, 29, 37, 45, and 53
Change From Baseline in Pulse Rate Over Time
Time frame: 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)
Change From Baseline in Respiratory Rate Over Time
Time frame: 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)
Change From Baseline in Body Temperature Over Time
Time frame: 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)
Change From Baseline in Systolic Blood Pressure Over Time
Time frame: 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)
Change From Baseline in Diastolic Blood Pressure Over Time
Time frame: 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)
Plasma Trough Concentrations (Ctrough) of Emicizumab
Time frame: Predose at Weeks 1, 3, 5, 7, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, and 53
Incidence of Anti-Emicizumab Antibodies
Time frame: Weeks 1, 5, 17, 29, 41, and 53, and thereafter as clinically indicated until study completion (up to 8 years)
Incidence of De Novo Development of Factor VIII Inhibitors
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.
Time frame: As clinically indicated from baseline until study completion (up to 8 years)