Children's Hospital of Wisconsin, Medical College of Wisconsin, Milwaukee, WI, USA.
Metabolic Bone Disorders Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA; National Institute of Child Health and Development, National Institutes of Health, Bethesda, MD, USA.
Bone. 2021 Sep;150:116004. doi: 10.1016/j.bone.2021.116004. Epub 2021 May 11.
Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare mosaic disorder of Gα activation. Fibroblast Growth Factor 23 (FGF23)-mediated hypophosphatemia is a feature of FD/MAS that has been associated with poor skeletal outcomes. Standard therapy includes oral phosphorus and vitamin D analogs; however, treatment is limited by potential adverse renal and gastrointestinal effects. Burosumab is a monoclonal antibody to FGF23 approved to treat patients with X-linked hypophosphatemia and tumor-induced osteomalacia. There is currently no safety or efficacy data to support burosumab use in patients with FD/MAS.
A 7-year-old boy with severe FD/MAS presented with persistent hypophosphatemia and skeletal complications despite conventional treatment with oral phosphate and calcitriol. He was started on burosumab and achieved sustained normalization of serum phosphorus and marked improvement in alkaline phosphatase levels. This was accompanied by an encouraging clinical response, including decreased bone pain, improved muscle strength, and improved ambulation. No adverse effects of burosumab therapy were observed.
This is the first reported case of burosumab treatment in a patient with FD/MAS. The encouraging biochemical and clinical response in this patient highlights the need for future studies to explore the safety and efficacy of burosumab in the FD/MAS pediatric population.
纤维性骨发育不良/ McCune-Albright 综合征（FD/MAS）是一种罕见的 Gα 激活嵌合体疾病。成纤维细胞生长因子 23（FGF23）介导的低磷血症是 FD/MAS 的特征，与骨骼不良结局有关。标准治疗包括口服磷和维生素 D 类似物；然而，治疗受到潜在的肾脏和胃肠道不良反应的限制。Burosumab 是一种针对 FGF23 的单克隆抗体，已被批准用于治疗 X 连锁低磷血症和肿瘤诱导性骨软化症患者。目前尚无安全性或疗效数据支持在 FD/MAS 患者中使用 burosumab。
一名 7 岁男孩患有严重的 FD/MAS，尽管接受了口服磷酸盐和骨化三醇的常规治疗，但仍持续出现低磷血症和骨骼并发症。他开始使用 burosumab，血清磷持续正常化，碱性磷酸酶水平显著改善。这伴随着令人鼓舞的临床反应，包括骨痛减轻、肌肉力量增强和行走能力改善。未观察到 burosumab 治疗的不良反应。
这是首例报告的 FD/MAS 患者使用 burosumab 治疗的病例。该患者的生化和临床反应令人鼓舞，强调需要进一步研究探索 burosumab 在 FD/MAS 儿科人群中的安全性和疗效。
