Updated clinical practice recommendations established burosumab as the first-line treatment in pediatric patients with symptomatic X-linked hypophosphatemia and provided revised guidance on diagnosis and management across age groups.
The 2024 guidelines, published in Nature Reviews Nephrology, marked a change from the 2019 recommendations, which relied on limited burosumab efficacy data. Burosumab is now recommended as the primary therapy for pediatric patients with X-linked hypophosphatemia (XLH) presenting with rickets, elevated alkaline phosphatase (ALP), or radiologic signs of rickets. Burosumab demonstrated improved safety and efficacy compared with conventional treatments, with reduced gastrointestinal issues and a lower risk of hyperparathyroidism.
Among adult patients, burosumab was advised for those with pseudofractures, inadequate response to oral phosphate and active vitamin D, or adverse effects from conventional therapies. In a randomized trial, burosumab achieved a 43.1% healing rate for active fractures by week 24 compared with 7.7% in placebo recipients.
The guidelines recommended biweekly dosing of 0.8 mg/kg in pediatric patients (adjustable to 0.4 mg/kg) and monthly doses of 1.0 mg/kg in adult patients, with a maximum of 90 mg. Monitoring included serum phosphate levels but not fibroblast growth factor 23 (FGF23) levels.
Long-term studies reported reduced dental abscesses in young pediatric patients treated with burosumab compared with conventional therapies. However, this benefit was less evident in older pediatric patients, underscoring the importance of early treatment.
Burosumab treatment improved the quality of life in pediatric patients, reducing bone pain and fatigue and enhancing physical health scores over 40 to 64 weeks.
Burosumab was contraindicated during pregnancy as a result of potential reproductive toxicity. Contraception was recommended for patients of childbearing potential.
The guidelines emphasized the need for further research to develop clinical scores for evaluating treatment efficacy, optimize surgical timing, and assess long-term outcomes, including quality of life and bone deformity correction.
By standardizing care and incorporating new evidence, the updated recommendations aim to enhance outcomes in patients with XLH while addressing gaps in understanding this rare condition.
Conflict of interest disclosures can be found the guidelines.
