Patient and carer perceptions and acceptability of current management practices in paediatric X-linked...

X-linked hypophosphatemia (XLH) is an X-linked dominant condition where fibroblast growth factor-23 (FGF23) excess leads to hypophosphatemic rickets, lower limb bowing, and musculoskeletal pain. Burosumab, a monoclonal antibody against FGF23, has been shown to ameliorate the clinical phenotype of XLH and has recently been approved for use in many countries. This study aimed to evaluate patient and parental/caregiver perception of burosumab therapy and the acceptability of current management practices in Australia. Children with XLH and parents/carers were invited to respond to a survey on clinical and management information including use of telehealth, access to multidisciplinary team members, and perceptions and experience regarding burosumab therapy. This was a multi-centre, cross-sectional survey-based study involving 4 tertiary Australian children's hospitals. A total of 21 survey responses from parents/carers were received between December 2022 and October 2023. Mean (SD) age at time of survey was 12.7 (4.1) yr and median time on burosumab was 42 mo (range 2-100). Reported side effects of burosumab were limited to local skin reactions (38%, n = 8) and injection site pain (5%, n = 1), with the majority (62%, n = 13) reporting no side effects. Logistical issues (availability from the pharmacy or medical centre holiday closure) led to most instances of missed or delayed doses, which were reported by 24% (n = 5). Most participants reported seeing their specialist both face-to-face and via telehealth (64%, n = 14). The majority saw an endocrinologist (100%, n = 21) and orthopaedic surgeon (67%, n = 14), but only a small minority saw a psychologist (10%, n = 2). Answers to Likert scale questions revealed that most parents/carers and children reported a perceived improvement in physical and psychological symptoms and function with burosumab therapy. This study supports the use of recently published local guidelines to manage children with XLH on burosumab due to high satisfaction expressed by children and parents/carers. However, logistical issues leading to delayed or missed doses should be addressed.