The Wnt pathway has an important role in bone formation. Inactivation of 
sclerostin, an inhibitor of this pathway, has been associated with increased 
bone mass both in animal experiments and in human clinical trials. Romosozumab 
is a humanized monoclonal antibody targeting sclerostin. Preclinical studies 
showed that this antibody primarily increases bone formation resulting in 
increased bone mineral density. Initial studies carried out in humans are in 
line with data obtained in animals. If these results are confirmed in larger 
studies with fracture end-points, this monoclonal antibody with its anabolic 
action, will become a key drug in the treatment of osteoporosis.