The researchers’ chart review revealed a 17.5% cumulative infection rate over the two years before denosumab treatment was initiated, as well as a 19% hospitalization rate for infections prior to denosumab. No new infections occurred in the first year after initiating denosumab. After five years, the cumulative infection rate was 71.4% in the TNF group, 50% in the other biologics group and 62.5% in patients receiving treatment with denosumab and other TNF/biologics. This compares with results from the FREEDOM trial that found that, at three years, the cumulative incidence rate of infections was 52.9%. The most common infections documented in the current study were urinary tract infections (17.5%). Other common infection sites included lungs, skin and soft tissue.
Because the researchers did not see any new infections within the first year of treatment with denosumab, they hypothesized that any increase in infection risk with denosumab may be cumulative over time. They also note that the patients who developed recurrent infections had other risk factors, such as suboptimally controlled diabetes mellitus, underlying lung disease, recent surgery, urinary incontinence and recent glucocorticoid use. Of note, in the two patients with a history of treated latent tuberculosis, their tuberculosis was not reactivated.
“We were somewhat pleasantly surprised with these results,” acknowledges Dr. Chhibar. “We were concerned that the addition of denosumab, which is itself a biologic, to other biologic anti-rheumatic therapies, would indeed increase risk of infections, or perhaps at least serious infections. However, we were reassured that our 40 patients treated [for] five years with both denosumab and anti-rheumatic biologics had no more infections than expected by their underlying disease, co-morbidities and treatments, and when compared with rates of infections before starting denosumab or with other trials.”
Lara C. Pullen, PhD, is a medical writer based in the Chicago area.
References
- Cummings SR, San Martin J, McClung MR, et al. Denosumab for prevention of fractures in postmenopausal women with osteoporosis. N Engl J Med. 2009 Aug 20;361(8):756–765. doi: 10.1056/NEJMoa0809493. Epub 2009 Aug 11.
- Chhibar P, Ehresmann G. Increased infection risk with concomitant use of RANK ligand-inhibitor, denosumab and TNF-inhibitors or other biologics: Reality or illusion? Long-term experience at the University of Southern California [abstract]. Arthritis Rheumatol. 2016 Oct;68(suppl 10).
