Patients: 71 male patients who had completed either the paradigm 2 or paradigm 3 clinical trials. Patients were aged 13 to 70 years with hemophilia B and had FIX activity ≤2 IU/dL, no history of inhibitors to FIX, and at least 150 exposure days to any FIX product.

Study design: Open-label, non-randomized, multicenter trial with four treatment arms: three once-weekly prophylactic groups (10 IU/kg, 40 IU/kg, and 80 IU/kg) and one on-demand group (40 IU/kg for mild and moderate bleeds, 80 IU/kg for severe bleeds). All patients were expected to have at least 50 additional exposure days to Rebinyn^® during this extension trial. Treatment was mostly administered at home, with 2 clinic visits in the first 6 months and once every 6 months following. Prophylaxis patients received treatment during clinic visits, to allow pre-dose and post-dose blood samples and assessments.

Primary endpoint: Development of FIX inhibitors.

Secondary endpoints: Efficacy of Rebinyn^® for bleed prophylaxis and when treating spontaneous or traumatic bleeding episodes. Assessment included number of bleeds and FIX activity.

Patients: Study included 42 Canadian patients with hemophilia B and treated with Rebinyn^® prophylaxis for at least 6 months. Patients spanned all age groups and severity of hemophilia B. Secondary endpoint analysis included only those patients (n=42) with at least 6 months of data recorded with a previous product before switching to Rebinyn^®.

Design: Retrospective analysis of data reported to the Canadian Bleeding Disorders Registry (CBDR) by 11 hemophilia treatment centers from April 2018 through March 2021. Two study groups, patients previously treated with Alprolix^® and patients previously treated with BeneFIX^®, were analyzed using negative binomial regression, to compare bleed rates, and a shared frailty gamma model, to compare recurrent bleeding incidents. CBDR formulary mandated a switch from Alprolix^® to Rebinyn^®, and patients had the option to switch from BeneFIX^® to Rebinyn^®.

Primary endpoint: Efficacy of Rebinyn^® prophylaxis, including annualized bleeding rate, bleeding frequency in target joints, and target joint progression.

Secondary endpoint: Change in efficacy metrics and number of infusions required to treat a bleeding episode when patients switched to Rebinyn^® from a previous FIX product.

Patients: 25 previously treated children with severe or moderately severe hemophilia B. Children were ≤12 years old, had an FIX activity level of ≤2%, had a history of ≥ 50 exposure days to other FIX products, and weighed ≥10 kg.

Study design: International, multicenter, open-label, non-controlled, single-arm trial designed following EMA guidelines. Patients were stratified into two age groups: 0–6 years and 7–12 years. The trial consisted of a main phase of 52 weeks, and an extension phase. All patients received a fixed dose of 40 IU/kg of Rebinyn^® intravenously once weekly for prophylaxis. A pharmacokinetic (PK) assessment was conducted after the first dose of Rebinyn^®, with the last PK sample collected 1 week after that dose and just prior to administration of the second dose. Breakthrough bleeds were treated with a single dose of 40 IU/kg of Rebinyn^® (mild-to-moderate bleeds) or 80 IU/kg of Rebinyn^® (severe bleeds).⁵

Primary endpoint: Immunogenicity of Rebinyn^® as measured by the occurrence of FIX inhibitors (≥0.6 BU) over at least 50 exposure days.

Secondary endpoint: Efficacy of Rebinyn^® in long-term prophylaxis as assessed by the estimated number of bleeds per year, success in treating breakthrough bleeds, and safety other than immunogenicity. FIX activity was also a secondary endpoint, measured after the first single-dose exposure and again at steady state.