The medications widely used for the treatment and prevention of osteoporosis are the bisphosphonates: Boniva (ibandronate), Fosamax (alendronate) and Actonel (risedronate). While these are safe and effective, concerns have been raised about some side effects like atypical fractures and jaw osteonecrosis (“dead” jaw bone) making some folks leery of taking these meds.
Enter Prolia. Prolia is a new medication that works quite differently then the bisphosphonates and is generating buzz for the treatment and prevention of osteoporosis. Prolia (denosumab) is what is called a monoclonal antibody and works by inhibiting the cells that break down bone (osteoclasts). Prolia decreases bone resorption, increases bone mineral density, and decreases the risk of fractures.
Sounds promising, but what else do we know about Prolia?
• It’s expensive. Really expensive. It’s about 900 dollars for an injection.
• Prolia is an injection given once every six months.
• Prolia has been shown to lower the risk of vertebral and hip fractures compared to placebo.
• Jaw osteonecrosis has been shown to occur in trials with the use of Prolia but this was in the group treated for longer than 6 years and it was very rare.
• There are no studies on Prolia for the treatment of osteoporosis in men (yet). Prolia has been shown to reduce the risk of vertebral (spine) fractures in men with prostate cancer taking lupron (or another anti-androgen).
• Given the absence of long-term safety data, Prolia is not recommended for osteoporosis prevention unless you are at high risk for fracture and have failed or cannot tolerate other available therapies.
The upshot here is until we know more about how safe and effective Prolia is, oral bisphosphonates should be used as initial therapy because of their efficacy, favorable cost and the availability of long-term safety data. Having said that, Prolia is an exciting new way of targeting bone loss and if we continue to get good news, it may be a way to go.