Approval Probability
TA Base Rate
Adjusted LOA
ML Risk
BIIB031 · 1 trial · 1 indication
An inhibitor test result ≥0.6 Bethesda units (BU)/mL, confirmed on 2 separate samples drawn 2 to 4 weeks apart, was considered positive. Both tests were to be performed by the central laboratory using the Nijmegen-modified Bethesda Assay. Incidences were summarized for any positive inhibitor for participants with ≥50 EDs to rFVIIIFc. In addition, the incidence for all participants, regardless of their EDs to rFVIIIFc, was also summarized. An exact 95% CI for the proportion of participants with a confirmed inhibitor was calculated using the Clopper-Pearson exact method for a binomial proportion.
| Arm | Type | Description |
|---|---|---|
| All participants | EXPERIMENTAL | PK subgroup: After a Washout Period of ≥72 hours, at the Baseline Visit (28±7 days prior to Day 1), participants receive a single IV injection of prestudy FVIII over 5 (±2) minutes at a dose of 50 IU/kg, rounded up to the nearest 250 IU increment, for a PK assessment. Following a second Washout Period of ≥72 hours, participants receive a single IV injection of rFVIIIFc over 5 (±2) minutes at a dose of 50 IU/kg for PK assessment. The first prophylactic dose of rFVIIIFc is administered at a starting dose of 25 IU/kg IV injection on Day 1 and 50 IU/kg on Day 4. Dose increases to a maximum of 80 IU/kg, and frequency of administration to a minimum interval of once every 2 days, are allowed as indicated. Non-PK subgroup: On Day 1, a first prophylactic dose of rFVIIIFc of 25 IU/kg IV injection is given, followed by a dose of 50 IU/kg on Day 4. Dose increases to a maximum of 80 IU/kg, and frequency of administration to a minimum interval of once every 2 days, are allowed as indicated. |
| Name | Type | Description |
|---|---|---|
| BIIB031 (rFVIIIFc) | DRUG | Vials of rFVIIIFc were combined as needed, based on the actual labeled potency to achieve the participant's calculated dose. Partial vial use was allowed, in order to achieve the calculated dose. |
| FVIII (PK subgroup only) | DRUG | Baseline prestudy FVIII dosing in participants who enter the PK subgroup. Vials of prestudy FVIII were combined as needed, based on the nominal labeled potency (e.g., 250 IU, 500 IU, and 1000 IU), to achieve the participant's calculated dose. |
Key Inclusion Criteria: * Severe hemophilia A defined as \<1 IU/dL (\<1%) endogenous FVIII * Male \<12 years of age and weight ≥13 kg * History of at least 50 documented prior exposure days to FVIII * No current, or history of, inhibitor development to FVIII Key Exclusion Criteria: * Other coagul...