Experiences with Efanesoctocog Alfa: Exit Interviews with Caregivers of Previously Treated XTEND-Kids Phase III Trial Patients with Haemophilia A

BACKGROUND: Until recently, most treatments for haemophilia A consisted of regular prophylaxis with factor VIII (FVIII) replacement therapy, which, to be effective, needed to be given multiple times per week. Efanesoctocog alfa is a once-weekly FVIII replacement therapy that has demonstrated highly effective bleed prevention in patients aged < 12 years with haemophilia A during the 52-week phase III XTEND-Kids trial (ClinicalTrials.gov identifier: NCT04759131). OBJECTIVES: We conducted exit interviews with caregivers of XTEND-Kids trial patients to understand their experiences with efanesoctocog alfa. METHODS: Caregivers were asked questions, via telephone exit interviews, on their pre- and post-trial experiences to determine the impact of efanesoctocog alfa on their and their child's lives. Interviews were audio-recorded, transcribed, and analysed using an applied thematic analysis to identify key themes and trends. Quantitative data were obtained to inform the qualitative analysis. RESULTS: Interviews were conducted with 19 caregivers of 20 children with haemophilia A. Prior to the trial, caregivers described substantial impacts on children's mood and emotional wellbeing (reported for 19/20 [95%] of the children by their caregivers), physical activity (14/20; 70%), and caregiver burden. After the switch to efanesoctocog alfa, most caregivers reported improvements across multiple domains, including reduced bleeding and bruising, improved mood and emotional wellbeing (18/19; 94.7%), and increased physical activity (10/14; 71.4%). All reported at least one improvement in their child; many described reduced treatment burden due to less frequent injections. CONCLUSIONS: Caregiver-reported outcomes suggest that efanesoctocog alfa may meaningfully reduce disease and treatment burden, with improvements observed across children's daily functioning and emotional wellbeing, and caregiver experience.