Anti-Human RANKL (Denosumab) (LT2800-GRP)

Osteoporosis is a disease of bone microarchitecture deterioration commonly seen in postmenopausal women1. Estrogen deficiency leads to low bone mass and increased bone fragility due to bone resorption increasing more than formation. Those affected have an increased risk of fracture. RANKL (receptor activator of NFκB ligand) is a TNF family member that acts as a key bone resorption protein by mediating osteoclast formation, activation, and survival via activating its receptor RANK1,2. Denosumab, a fully human monoclonal antibody originally generated using transgenic Xenomouse technology, selectively and with high affinity binds to and inhibits human RANKL, thus preventing interaction with and activation of its receptor RANK on the surface of osteoclasts and their precursors2. This blocking activity inhibits the formation, function, and survival of osteoclasts, resulting in reduced bone resorption and consequently reduces the risk of vertebral, nonvertebral and hip fractures. Denosumab increases bone mineral density (BMD) and trabecular and cortical bone strength, with continued antifracture and BMD benefits over 10 years of therapy. Bone resorption is inhibited in cynomolgus monkeys and humans, but not normal mice or rats. Unlike bisphosphonates, denosumab is not incorporated into bone and its effects on bone turnover markers, BMD and histomorphometric measures are generally reversed upon its discontinuation1.