ABSTRACT
INTRODUCTION: In 2017, all people with severe hemophilia B in Ireland switched to recombinant factor IX Fc fusion protein concentrate (rFIXFc) prophylaxis. Patient-reported outcomes (PROs) and health-related quality of life (HRQoL) are important to evaluate with new treatments. AIMS: To assess HRQoL in people with severe hemophilia B and their experience after switching to rFIXFc prophylaxis. METHODS: Participants completed a Patient Reported Outcomes Burden and Experience (PROBE) questionnaire on initiation and following two years of rFIXFc prophylaxis. The PROBE questionnaire has four domains: demographics, general health, haemophilia-specific, and European Quality of Life 5-Dimensions (EQ-5D-5L) questionnaire. RESULTS: Twenty-three participants completed the questionnaire at both time points. The number of activities where chronic pain occurred and interfered with the activity was reduced by 25% and 33%, respectively (P < .001), following two years of rFIXFc prophylaxis. There was a 9% decrease in chronic pain during the second year of rFIXFc prophylaxis compared to baseline, but the rate remained high, at 74%. A 25% reduction in the number of affected activities of daily living (ADLs) was reported following 2 years of rFIXFc prophylaxis (P = .007). The most common health problems were arthritis, hypertension, anxiety/depression, and gingivitis. The median EQ-5D-5L score was similar following two years of rFIXFc prophylaxis, 0.76 (range, -0.01 to 0.95), compared to 0.77 (range, 0.36-1) at baseline. CONCLUSION: This study of real-world patient experience using PROs demonstrates a reduction in chronic pain and improvement in ADLs in participants after switching to rFIXFc prophylaxis. It provides important insights into patient-identified health care needs and living with severe hemophilia B.
ABSTRACT
INTRODUCTION: In 2017, all people with severe haemophilia B (PWSHB) in Ireland switched from standard half-life (SHL) recombinant FIX (rFIX) to rFIX Fc fusion protein (rFIXFc) prophylaxis. AIMS: To evaluate prophylaxis regimens, bleeding rates and factor usage for two years of rFIXFc prophylaxis in a real-world setting. METHODS: Data collected retrospectively from electronic diaries and medical records of PWSHB for a two-year period on rFIXFc prophylaxis were compared with paired baseline data on SHL rFIX treatment. RESULTS: 28 PWSHB (≥18 years) were enrolled, and at switchover 79% were receiving prophylaxis and 21% episodic treatment with SHL rFIX. At 24 months following switchover, all remained on rFIXFc prophylaxis with reduced infusion frequency; median dose per infusion once weekly (55 IU/kg, 20/28), every 10 days (63 IU/kg, 2/28) or every 14 days (98 IU/kg, 6/28). Median annualised bleed rate improved significantly on rFIXFc prophylaxis (2.0 versus 3.3 on SHL FIX) (p = 0.01). Median FIX trough level with once-weekly infusions was 0.09 IU/ml (0.06-0.14 IU/ml). Management of bleeding episodes was similar with rFIXFc and SHL rFIX; one infusion was sufficient to treat 74% and 77% of bleeds, respectively, with similar total median treatment per bleeding episode. Factor consumption reduced by 28% with rFIXFc prophylaxis (57 IU/kg/week, range 40-86 IU/kg/week) compared with SHL rFIX (79 IU/kg/week, range 44-210 IU/kg/week) (p = 0.002). CONCLUSION: This study provides important insights into real-world experience of switching to rFIXFc prophylaxis in an adult population, demonstrating high rates of prophylaxis, with reduced infusion frequency, bleeding and FIX consumption.