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Comparative Study
. 2025 Nov;42(11):5696-5707.
doi: 10.1007/s12325-025-03336-y. Epub 2025 Sep 18.

Comparing Real-World Outcomes of Prophylaxis with Extended Half-life Factor IX (rIX-FP vs. rFIXFc and N9-GP) for Haemophilia B: An Analysis of Medical Chart Data from Germany

Martin Olivieri  1 , Songkai Yan  2 , Ying Yang  3 , Radovan Tomic  4 , Thomas Linhoff  5 , Xiang Zhang  6 , Douglass Drelich  6 , Natalie Jakobs  3 , Wolfgang Miesbach  7
Affiliations
Comparative Study

Comparing Real-World Outcomes of Prophylaxis with Extended Half-life Factor IX (rIX-FP vs. rFIXFc and N9-GP) for Haemophilia B: An Analysis of Medical Chart Data from Germany

Martin Olivieri et al. Adv Ther. 2025 Nov.

Abstract

Introduction: In Germany, three extended half-life factor IX (FIX) products are commonly used to treat people with haemophilia B (PwHB). However, there remains a critical need to differentiate treatments for PwHB. The aim of this study was to assess the effectiveness and utilisation of rIX-FP compared with rFIXFc and N9-GP for prophylaxis in clinical practice in Germany.

Methods: A retrospective chart review was performed for PwHB aged ≥ 12 years with moderate/severe haemophilia B, who received prophylaxis with rIX-FP, rFIXFc or N9-GP for ≥ 12 months. The primary outcome was FIX consumption; secondary outcomes included annualised bleeding rate (ABR), annualised spontaneous bleeding rate (AsBR) and annualised joint bleeding rate (AjBR).

Results: The study included 138 PwHB: rIX-FP, n = 52; rFIXFc, n = 55; and N9-GP, n = 31. Mean FIX consumption with rIX-FP (46.9 IU/kg/week) was significantly lower than that of rFIXFc (70.1 IU/kg/week, p = 0.0083) but not significantly different from N9-GP (47.2 IU/kg/week, p = 0.9331). PwHB receiving rIX-FP prophylaxis had significantly lower mean bleeding rates than those receiving N9-GP (ABR: 0.8 vs. 1.5, p = 0.0472; AsBR: 0.1 vs. 0.6, p = 0.0092; and AjBR: 0.2 vs. 0.6, p = 0.0140). Bleeding rates for rIX-FP and rFIXFc did not differ significantly.

Conclusion: rIX-FP prophylaxis was associated with significantly lower FIX consumption and numerically (but not significantly) lower bleeding rates compared with rFIXFc. Compared to N9-GP, prophylaxis with rIX-FP was associated with similar FIX consumption and significantly lower bleeding rates.

Keywords: Annualised bleeding rates; Dosing interval; Factor consumption; Haemophilia B; N9-GP; Prophylaxis; rFIXFc; rIX-FP.

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Conflict of interest statement

Declarations. Conflict of Interest: Martin Olivieri has received grants/research support from Bayer, Biomarin, Biotest, Takeda, CSL Behring Octapharma, Pfizer, Shire, Roche, Stago and Swedish Orphan Biovitrum, consultancy and speaker fees from Bayer, BioMarin, Biotest, Novo Nordisk, Takeda, CSL Behring, Pfizer, Roche and Swedish Orphan Biovitrum; Songkai Yan, Radovan Tomic, Xiang Zhang, Thomas Linhoff and Douglass Drelich are employees of CSL Behring; Ying Yang and Natalie Jakobs are employees of Adivo Associates; Wolfgang Miesbach received consultation fees from Bayer, BioMarin, Biotest, CSL Behring, Chugai, Freeline, LFB, Novo Nordisk, Octapharma, Pfizer, Regeneron, Roche, Sanofi, Sobi, Takeda/Shire, uniQure. Ethical Approval: Following institutional review board (IBR) evaluation, the study was determined to be exempt from patient informed consent under category 4 (IBR case name: CSL Behring - 2023-168, Patient chart analysis to assess real-world outcomes and utilisation of recombinant FIX products in Germany and Italy—IRB protocol#: [Pro00072842]) as secondary research for which consent is not required; this applied to all 31 haemophilia treatment centres involved in the study.

Figures

Fig. 1
Fig. 1
Mean dosing interval (days) by product: a PwHB, b people with severe haemophilia B, c people with moderate haemophilia B. PwHB people with haemophilia B. Bars show 95% confidence intervals
See this image and copyright information in PMC

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