Men's Osteoporosis Support Group
Denosumab and infection risk
Osteoporos Int. 2011 Sep 3. [Epub ahead of print]. Infections in postmenopausal women with osteoporosis treated with denosumab or placebo: coincidence or causal association? Watts NB and others. PMID: 21892677. This research involves denosumab (Prolia) which is approved for treatment of postmenopausal osteoporosis in women. It has also been used in research on men with prostate cancer, and presumably is available as an off-label medication for men with osteoporosis. Previous studies have found potential problems related to infections and cellulitis. This study investigated further this possible infection correlation.
There were 3,902 women who received denosumab injections every six months and 3,906 women who received placebo. All then were tracked to record any serious adverse events, particularly “Infections and Infestations.” The authors found, “No relationship was observed between serious adverse events of infections and timing of administration or duration of exposure to denosumab.” This was the case even though there were more serious events in the denosumab group than in the placebo group.
The authors concluded, “Serious adverse events of infections that occurred with denosumab treatment had heterogeneous etiology, with no clear clinical pattern to suggest a relationship to time or duration of exposure to denosumab.”
Editor's comments. A recent study by Smith MR and others, PMID: 21898590, found that denosumab changed bone turnover markers in men receiving androgen deprivation therapy for prostate cancer, which would indicate it was protective of loss of BMD during that therapy. A 2010 Update has additional information regarding denosumab.
One nice feature of denosumab for treatment of osteoporosis is the twice-yearly injections would be convenient. But the infection risk issue has been a concern. The Watts and others study was unable to detect a clearcut correlation between the timing of denosumab injections or length of exposure to serious infections, which is positive. But there were more serious incidences in the denosumab group—for whatever reason. Thus I don't think we have heard the last of this issue regarding infections. Hopefully additional studies will be done that will produce more definitive results.