PB1331 - NEW PARADIGM IN THE TREATMENT OF HEMOPHILIA B: SPANISH REAL-LIFE EXPERIENCE WITH rIX-FP

Background: Prophylaxis regimen with extended half-life factors, in patients with hemophilia B (HB), allows to reduce treatment associated burden.

Aims: To describe experience with rIX-FP (Recombinant Coagulation Factor IX Albumin Fusion Protein) at Hospital Universitario de Cruces and Hospital Txagorritxu.

Methods: This study includes 12 patients with rIX-FP. The treatment switch to those who are on prophylaxis was guided by individualized pharmacokinetic study (WAPPS Hemo platform).

Results: All patients were on treatment with rFIX-SHL (short half life) or plasma derivated factor and the average follow-up was 7.6 months.
The average age was 41.3 (only one patient was pediatric), and there were 8 patients with severe HB and 4 with moderate HB. Eight patients were on a prophylactic regimen and 4 were treated on demand with the prior treatment (one patient remains OD with the current treatment). A description of the patients is shown in Table 1.
After several months of follow-up, patients showed a significant improvement in their quality of life (QoL), and hospital burden has decreased considerably after the switch to rIX-FP, as they are more protected with higher trough levels, have improved their joint pain and their arthropathies. The ABR (annualized bleeding rate) was 0, except for one patient who presented a psoas hematoma secondary to intense physical exercise. In addition, FIX consumption was reduced after the switch to rIX-FP.
Two patients underwent two surgeries (Table 2) with excellent haemostatic response and neither patient developed inhibitor.

Conclusion(s): The switch from SHL to rIX-FP has led to a very significant improvement in the QoL of patients, reducing the number of infusions, increasing joint protection and achieving much higher trough levels, while maintaining an adequate safety profile and reducing consumption.