Long-Term Safety and Efficacy of Recombinant Coagulation Factor IX Albumin Fusion Protein (rIX-FP) in Previously Treated Pediatric Patients with Hemophilia B: Results from a Phase 3b Extension Study

Gili Kenet, Hervé Chambost, Christoph Male, Susan Halimeh, Thierry Lambert, Yanyan Li, Wilfried Seifert, Elena Santagostino*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Introduction: A phase 3b extension study evaluated the long-term safety and efficacy of a recombinant fusion protein-linking coagulation factor IX (FIX) with albumin (rIX-FP) for the routine prophylaxis and on-demand treatment of bleeding in pediatric hemophilia B patients. Methods: Previously treated patients aged <12 years with moderate to severe hemophilia B enrolled in a 3-year extension study following a phase 3 pivotal study in which they received weekly rIX-FP prophylaxis. In the extension study, they could maintain or extend their prophylaxis interval to every 10 or 14 days if they were well controlled on the 7-day regimen. Results: Compared with their initial regimen, by the end of the study, dosing intervals were the same, extended, and shortened in 16, 4, and 4 patients, respectively. Very low annualized spontaneous bleeding rates (AsBRs) were observed; median AsBR was 0.0 for the 7-and 10-day regimens, and 1.1 for the 14-day regimen. The 7-and 14-day regimens were comparable in preventing spontaneous bleeds; mean (95% confidence interval) difference in AsBR of-1.2 (-2.6 to 0.3) bleeding episodes/year/subject. Overall, 96% of bleeding episodes were successfully treated with one or two injections of rIX-FP. Patients on a 14-day regimen maintained a mean steady-state trough FIX level of >7.2 IU/dL. No patient developed an inhibitor. Conclusion: This extension study demonstrated the long-term safety and efficacy of weekly rIX-FP in pediatric patients. Additionally, it showed that adequate bleed protection can be achieved with 10-or 14-day rIX-FP regimens in selected pediatric patients while maintaining safety.

Original languageEnglish
Pages (from-to)599-606
Number of pages8
JournalThrombosis and Haemostasis
Volume120
Issue number4
DOIs
StatePublished - 1 Apr 2020

Keywords

  • factor IX
  • hemophilia B
  • prophylaxis
  • rIX-FP
  • recombinant fusion protein

Fingerprint

Dive into the research topics of 'Long-Term Safety and Efficacy of Recombinant Coagulation Factor IX Albumin Fusion Protein (rIX-FP) in Previously Treated Pediatric Patients with Hemophilia B: Results from a Phase 3b Extension Study'. Together they form a unique fingerprint.

Cite this