Conditions: Hemophilia B
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 30
Healthy volunteers: no

Brief summary:
The primary objective of the study is to evaluate the safety of Recombinant Human Coagulation Factor IX Fc Fusion Protein (rFIXFc) in previously treated pediatric subjects with hemophilia B. Secondary objectives of this study in this study population are as follows: to evaluate the efficacy of rFIXFc for prevention and treatment of bleeding episodes; to evaluate and assess the pharmacokinetics (PK) of rFIXFc; to evaluate rFIXFc consumption for prevention and treatment of bleeding episodes

Detailed description:
At the Baseline visit (28 ± 7 days prior to Day 1), participants receive a single IV injection of prestudy FIX over 10 (±5) minutes in the clinic under medical supervision at a dose of 50 IU/kg. A washout period with no FIX treatment is required prior to administration of prestudy FIX and prior to rFIXFc. A PK assessment is done with prestudy FIX and also done with rFIXFc on Day 1. After completing the PK assessments, participants begin weekly prophylactic treatment with rFIXFc for approximately 50 weeks, to obtain 50 EDs. One ED is defined as a 24-hour period in which a participant received 1 or more doses of rFIXFc, with the time of the first injection of rFIXFc defined as the start of the ED.

Arms:
arm 1: At Baseline and at Day 1, participants receive a single intravenous (IV) injection of prestudy FIX and rFIXFc, respectively, over 10 (±5) minutes at a dose of 50 IU/kg. Immediately after the last PK sampling, the first prophylactic dose of approximately 50 to 60 IU/kg will be administered in clinic as an IV injection.

Dose could be increased or decreased in increments of 10 IU/kg; increases to a maximum of 100 IU/kg and frequency of administration to a maximum of twice weekly, were allowed as indicated.

Interventions: intervention 1: rFIXFc intervention 2: FIX
Intervention descriptions: intervention 1: Vials of rFIXFc 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. intervention 2: Vials of prestudy FIX (provided by the participants) 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.

Protocol document: