Cortical and trabecular bone undergo a continuous and balanced remodeling process, consisting of an osteoclast-mediated bone-resorption phase and an osteoblast- mediated bone-formation phase. An imbalance in this process, which favours bone resorption, results in bone loss and in damage to the skeletal microarchitecture. A new targeted anti-resorptive approach is represented by the inhibition of RANK ligand (RANKL), which is one of the primary mediators of osteoclast activity, essential for osteoclast formation, function and survival.