Study of Recombinant Coagulation Factor IX Fc Fusion Protein, BIIB029, in Previously Treated Pediatric Participants With Hemophilia B (Kids B-LONG)

Bioverativ

Status and phase: Completed; Phase 3

Conditions: Hemophilia B

Treatments: Drug: rFIXFc; Drug: FIX

Study type: Interventional

Funder types: Industry

Identifiers

NCT01440946

2011-003076-36 (EudraCT Number)

9HB02PED

Details and patient eligibility

About

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

Full 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.

Enrollment: 30 patients

Sex: Male

Ages: Under 11 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

• Severe hemophilia B defined as ≤ 2 IU/dl (≤ 2%) endogenous FIX
• Male < 12 years and weight ≥ 13 kg
• History of at least 50 documented prior exposure days to FIX
• No history of, or currently detectable, inhibitor

Key Exclusion Criteria:

• Other coagulation disorders in addition to Hemophilia B
• History of anaphylaxis associated with any FIX or IV immunoglobulin administration

NOTE: Other protocol defined Inclusion/ Exclusion criteria may apply.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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30 participants in 1 patient group

rFIXFc Prophylaxis

Experimental group

Description:

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.

Treatment:

Drug: FIX

Drug: rFIXFc