Skip to main content
ISTH 2023 Main banner
Back

    Poster Networking

    Hemophilia and Rare Bleeding Disorders

    Poster Networking Session

    PB0692 - Matching-adjusted indirect comparison of rIX-FP versus rFIXFc for prophylactic treatment of hemophilia B

    Monday, June 26, 2023
    18:30 – 19:30 ET
    Room: Exhibition

      Co-Author(s)

    • SY

      Songkai Yan

      Director, Global Health Economics
      CSL Behring, King of Prussia, PA, USA
      King of Prussia, Pennsylvania, United States

      • Co-Author(s)

    • BH

      Becky Hooper

      Manager, Data Analytics & Evidence Synthesis
      EVERSANA, Burlington, Canada
      Burlington, Ontario, Canada

    • SB

      Soraya Benchikh El Fegoun

      Global Medical Director
      CSL Behring, Bern, Switzerland
      Bern, Bern, Switzerland

    • WS

      Wilfried Seifert

      Director Clinical Development
      CSL Behring, Marburg, Germany
      Marburg, Hessen, Germany

    • JS

      Jason Steenkamp

      Manager, Biostatistics
      EVERSANA, Burlington, Canada
      Burlington, Ontario, Canada

      • Presenting Author(s)

    • Maria Elisa Mancuso, MD, PhD

      Senior Hematology Consultant
      Center for Thrombosis and Hemorrhagic Diseases, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
      Milan, Lombardia, Italy

    Background: Recombinant factor IX (FIX) molecules with enhanced PK profile allow for longer dosing intervals with higher protection levels in treating hemophilia B patients. Albutrepenonacog alfa (Idelvion©), recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP), was assessed in the PROLONG-9FP trial. Eftrenonacog alfa (Alprolix©), recombinant FIX Fc fusion protein (rFIXFc), was evaluated in the B-LONG trial. The comparative efficacy of these treatments has not been assessed in head-to-head trials.

    Aims: This study aimed to estimate the comparative efficacy of rIX-FP versus rFIXFc using matching-adjusted indirect comparison (MAIC).

    Methods: MAICs leveraged individual patient data (IPD) from PROLONG-9FP and published summary-level data from B-LONG of patients who received weekly prophylaxis regimens. Where possible, baseline characteristics from PROLONG-9FP were adjusted to those in B-LONG by assigning weights to patients in the IPD. Annualized bleeding rate (ABR), spontaneous bleeding rate (AsBR), and joint bleeding rate (AjBR), and proportion of patients with no bleeds (% no bleeds), no spontaneous bleeds (% no spontaneous bleeds), and no joint bleeds (% no joint bleeds) were analyzed.

    Results: In the main analysis, rIX-FP was associated with statistically significantly lower AsBR (rate ratio [RR]: 0.42; 95% confidence interval [CI]: 0.22, 0.82; p = 0.0107), % no bleeds (odds ratio [OR]: 3.24; 95% CI: 1.41, 7.45; p = 0.0057), % no spontaneous bleeds (OR: 3.47; 95% CI: 1.56, 7.73; p = 0.0023), and % no joint bleeds (OR: 2.41; 95% CI: 1.10, 5.26; p = 0.0274) compared with rFIXFc, and numerically but not statistically significantly lower ABR (RR: 0.75; 95% CI: 0.32, 1.75; p = 0.5095) and AjBR (RR: 0.82; 95% CI: 0.37, 1.82; p = 0.6178) (Table 1). Additional analyses showed similar results.

    Conclusion(s): After adjusting for key baseline characteristics, rIX-FP demonstrated statistically significantly improved or numerically favorable results compared to rFIXFc across all efficacy outcomes compared.