PB1267 - Real World Experience of Taiwanese Hemophilia B Patients Treated with rFIX-FP as Prophylaxis Therapy

Background: Albuterpenonacog alfa ( rFIX-FP) is a fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin. rFIX-FP is an extended half life product for treatment of hemophilia B ( HB ), which has good efficacy of prophylaxis therapy for adult and paediatric HB patients. The real world experience reports on rFIX-FP for HB treatment in Asian countries are very limited and whichare far less than those reported from the west.

Aims: The aim of this study was to share our experience by using rFIX-FP as prophylaxis therapy for three HB patients.

Methods: The rFIX-FP as prophylaxis therapy for HB had been launched in Taiwan since Sep 1, 2020 and dose of 25-35 IU/kg/weekly for adult patients is allowed by our national insurance. Three adults male HB patients whose baseline characteristics are shown in Table 1 had received rFIX-FP as regular prophylaxis therapy for more than two years. Their clinical outcomes including trough level, annual spontaneous bleeding rate, annual spontaneous joint bleeding rate, the scores of hemophilic arthropathy assessed by HJHS and HEAD-US were retrospectively collected and analyzed.

Results: As shown in Tables 1 and 2, the trough level of two severe type HB patients ( patients 1 & 3 ) was 8.8~13.5% and only patient 1 with advanced hemophilic arthropathies had experienced spontaneous joint bleeding, the other two patients had no spontaneous joint bleeding. Hemophilic arthropathies of two patients ( patients 2 & 3 ) improved after switching to rFIX-FP therapy. Their both HIHS and HEAD-US scores were reduced at the first and second year follow up, as shown in Table 2.

Conclusion(s): Our study demonstrates that rFIX-FP was efficacious in the prophylaxis therapy for our three HB patients with much less bleeding and spontaneous joint bleeding events and prevention of progression of hemophilic arthropathies.