The search is endlessly on for a safe, effective osteoporosis treatment. One that may hit the market in 2017 inhibits the actions of a naturally-occurring protein, sclerostin. Sclerostin interferes with a signalling pathway (the Wnt signaling pathway) that spurs osteoblasts to grow bone. Sclerostin is secreted by osteoctyes embedded in bone matrix and seems to be a feedback mechanism to keep bones from growing too thick. If you inhibit sclerostin, as is seen in some disease states, you increase bone mass and strength.
Recently scientists have crystallized the antibody, and two pharmaceutical companies are moving ahead with clinical trials. They say the results are positive and that the drug could be available this year.
The clinical trials so far have been for 12 months, during which time no severe side effects were listed. It remains to be determined how long and how often treatment would be recommended.
It also remains unknown how long-term inhibition of sclerostin will affect the body as a whole.
Sclerostin Antibody Therapy for the Treatment of Osteoporosis:
Clinical Prospects and Challenges https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4899597/