Recombinant factor IX‐Fc fusion protein in severe hemophilia B: Patient‐reported outcomes and health‐related quality of life

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.