(6-Amino-1-hydroxyhexane-1,1-diyl)bis(phosphonic acid)

DescriptionNeridronic acid was launched in Italy as intravenous or intramuscular injection for the treatment of osteogenesis imperfecta. It is the first drug launched worldwide for this “orphan disease” characterized by a fragility of the bone. Sufferers risk frequent fractures commencing during infancy, eventually leading to bone deformation and a severe deterioration of the quality of life and life expectancy. Neridronic acid is structurally related to the second generation of bisphosphonates characterized by an amino terminal group and can be synthesized by treating E-aminocaproic acid with phosphoric acid and phosphorous trichloride. Bisphosphonates, synthetic analogs of the endogenous mineral deposition inhibitor pyrophosphate, are extremely potent inhibitors of bone resorption and increase bone mineral density, possibly by inhibiting the activity of osteoclasts and promoting the death of these bone-eroding cells. In vitro, neridronic acid was a poor inhibitor of phagocytosis, but significantly and dose dependently inhibited 8glucuronidase release and superoxide anion production in the rat peritoneal macrophage, two parameters that may have a part in bone resorption. In a clinical study on patients with osteogenesis imperfecta, neridronic acid increased remarkably bone mass in young growing individuals. In adults the changes were less important but still significant.

DescriptionNeridronic acid is an amino bisphosphonate that inhibits farnesyl pyrophosphate (FPP) synthase (IC50 = 388.2 nM in a cell-free assay). It decreases the differentiation of RAW 264.7 cells into osteoclasts in a CRL-12257 co-culture model of osteoclastogenesis when used at concentrations ranging from 0.001 to 100 μM. Neridronic acid (30 μM) inhibits FGF2-induced proliferation and tube formation in human umbilical vein endothelial cells (HUVECs). It reduces the loss of trabeculae and increases bone density in the tibial metaphysis of growing rats when administered subcutaneously at a dose of 0.1 mg/kg per day.