Safety and efficacy of Burosumab in patients with X-linked hypophosphatemia: A systematic review

X-linked hypophosphatemia is a rare genetic disorder caused by a loss-of-function mutation in the phosphate-regulating gene with homologies to endopeptidases on the X chromosome. It is characterized by early-onset skeletal deformities, hypophosphatemia, and elevated fibroblast growth factor 23 levels. The following mutations lead to recurrent fractures, osteoarthritis, joint stiffness, and a reduced life expectancy. Burosumab, a human monoclonal antibody, is considered a breakthrough in the treatment of X-linked hypophos-phatemia. MEDLINE, Cochrane Library, CENTRAL, Google Scholar, and clinicaltrials.gov were searched from inception through March 3rd, 2025. Overall, eight clinical trials investigating the effectiveness and safety of Burosumab in patients with X-linked hypophosphatemia were identified using the PRISMA guidelines. Out of which two randomized controlled trials exhibited a significant increase in serum phosphate. The other five single-arm studies reported instability in serum phosphate levels with variability in the dosing regimen. Furthermore, other primary outcomes; 1,25 dihydroxy vitamin D, serum calcium, and tubular maximum reabsorption of phosphate to glomerular filtration markedly optimized. Secondary outcomes assessing bone pain and ambulation indicated lower scores on the Brief Pain Inventory and Western Ontario and McMaster Universities Arthritis Index. Burosumab was well-tolerated by all participants, with only mild to moderate adverse events reported. The findings indicate significant improvement in levels of key biochemical markers; serum phosphate concentration, tubular maximum reabsorption of phosphate to glomerular filtration, 1,25 dihydroxy vitamin D after Burosumab use. A decrease in the level of pain and stiffness in joints was reported through the Brief Pain Inventory and Western Ontario and McMaster Universities Arthritis Index in most studies. Burosumab was well tolerated by participants from all included studies.