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