Burosumab is a recombinant human monoclonal antibody (IgG1) that binds to FGF23 and inhibits its activity, but to date, it is only indicated for XLH-linked hypophosphatemia; it is not indicated for CKD due to the risk of severe hyperphosphatemia that patients may experience [58]. Here, FGF23 is linked to X-linked hypophosphatemia.