Cessation of burosumab treatment due to end of skeletal growth (EoSG) in adolescents with XLH: A multi-centre case series.
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All Authors
Jarvis, C.
Ramakrishnan, R.
Dharmaraj, P.
Mushtaq, T.
Gupta, S.
Nixon, A.
Rylands, A.
Uday, S.
LTHT Author
Mushtaq, Talat
LTHT Department
Leeds Children's Hospital
Paediatric & Adolescent Endocrinology Service
Paediatric & Adolescent Endocrinology Service
Contributor Profession (Non Medical)
Publication Date
2024
Item Type
Conference Abstract
Language
Subject
Subject Headings
Abstract
OBJECTIVES: X-linked hypophosphataemia (XLH), a genetic condition of renal phosphate wasting secondary to excess FGF23 leads to significant musculoskeletal impairments. The National Health Service in England and Wales recommend burosumab (anti-FGF23 antibody) for treating XLH in children and young people with growing bones, with radiographic evidence of bone disease. This multi-centre case series captures real-world clinician recorded experience of burosumab cessation in adolescents at the end of skeletal growth (EoSG). METHOD(S): A retrospective descriptive case series of eight adolescents with XLH from four centres in England capturing medical history, biochemical data, radiological findings, and narratives of patient and caregiver reported experiences from clinical notes. RESULT(S): All patients switched to burosumab treatment from conventional therapy (oral phosphate and active Vitamin D) between 9-16 years. Median plasma phosphate levels at the end of conventional therapy were 0.59 mmol/L (n=7). Median burosumab treatment duration was 39 months (range 22-56 months) during which plasma phosphate levels increased to within or close to normal range for each patient (median 0.87 mmol/L, n=8). The reported benefits of burosumab treatment included leg straightening, improved bone biochemistry, pain, stiffness, mobility, energy, activity levels and mental health. Additionally, clinicians reported quicker recovery from orthopaedic surgery, improved school attendance and quality of life. Following cessation of burosumab at EoSG, plasma phosphate levels decreased to below the lower limit of normal (median 0.60 mmol/L, n=6). Six of the eight adolescents reported that pain returned or worsened within a few months of stopping burosumab. Six reported reductions in mobility and physical function, with increased pain. Decreased mobility compromised patients' ability to participate in physical education, physical activity, work/college and social activities. Five reported that stopping burosumab treatment had a marked impact on their mental wellbeing. Five restarted treatment with conventional therapy. CONCLUSION(S): Our case series provides insights into the positive experience of patients switching to burosumab treatment from conventional treatment which supports published evidence. Stopping burosumab treatment at EoSG had an adverse impact on pain, mobility and mental health in the majority of adolescents.
Journal
JBMR Plus