PB0503 - Clinical outcomes of people with hemophilia B treated with N9-GP in real-world settings: the Adelphi Disease Specific Programme™ hemophilia study

Background: Nonacog beta pegol (N9-GP) is an extended half-life, recombinant factor IX treatment approved for people with hemophilia B (PwHB). Clinical trials have established N9-GP safety and efficacy, supported by limited registry data. However, further investigation of patient outcomes is required in larger cohorts and broader populations from real-world settings.

Aims: To assess clinical outcomes (bleeding episodes and joint health status) of N9-GP-treated PwHB using real-world data.

Methods: Data on bleeding episodes and joint health were obtained from physician-completed patient record forms as part of the Adelphi Real World hemophilia Disease Specific Programme™, a retrospective, cross-sectional survey. Data were obtained between July–November 2023 from Germany, Italy, Spain, UK, USA, and Japan. Physician inclusion criteria were: (1) hematology specialty; (2) management of ≥5 people with hemophilia A/B. Only male PwHB (moderate to severe, without current inhibitors) who had received N9-GP for ≥3 months were included in the analysis.

Results: 119 PwHB receiving N9-GP prophylaxis were included in the analysis (characteristics shown in Table 1). 91% (105/116) received N9-GP weekly, with 88% (102/116) taking a 40 U/kg dose, as per label recommendations. 42% (n=50) PwHB receiving N9-GP prophylaxis were judged to have ever had hemophilia-related joint problems, of which most (n=33, 80.5%) had ≥1 target joint. In the 12 months after switching to N9-GP, median bleeds reduced to 0.0 (IQR, 0.0–2.0; n=60) from 1.0 (0.0–4.8; n=60) before switching; in addition, a greater proportion of PwHB experienced 0 bleeds after switching (67%, vs 45% before switching) (Table 2). Following N9-GP treatment initiation, the proportion of PwHB judged to have no problems with their joint health status increased from 59% (n=70) to 66% (n=78).

Conclusion(s): PwHB experienced a reduction in bleeding episodes and improvement in joint health after switching to N9-GP prophylaxis in real-world settings.