Of great interest is the recent identification of novel Pi regulating genes, PHEX and FGF23, that play a role in the pathophysiology of inherited (X-linked hypophosphatemia and autosomal dominant hypophosphatemic rickets) and acquired (oncogenic hypophosphatemic rickets) disorders characterized by renal Pi wasting and associated skeletal abnormalities.
Our data indicate that monotherapy with R568 reduced PTH and FGF23 synthesis in bone, but failed to restore vitamin D and phosphate metabolism and skeletal abnormalities in Hyp mice.