A recent study from Keio University School of Medicine in Tokyo showed that denosumab inhibited the progression of bone erosion and increased bone mineral density (BMD) in Japanese patients with rheumatoid arthritis (RA) who were on methotrexate. This study confirmed the findings of an earlier study conducted in the U.S. and Canada.
The study followed 350 patients who have lived with RA for 6 months to less than 5 years’ duration. They were randomized to receive placebo or denosumab in doses of 60 mg every 6 months, every 3 months, or every 2 months. Participants were grouped together according to their glucocorticoid use and rheumatoid factor (RF) status at baseline. Throughout the study, they continued taking methotrexate at 6 to 16 mg/week and were treated with supplemental vitamin D and calcium. Researchers found that the changes from baseline in modified Sharp erosion score at 12 months were lower in the denosumab groups than in the placebo group.
Denosumab has been approved for use by Health Canada for women with postmenopausal osteoporosis with clinical or radiographically-documented fracture due to osteoporosis. This medication is an anti-resorptive therapy that inhibits the development and activation of osteoclasts (the cells that eat away bone). It is administered by an injection under the skin, twice yearly.
In an interview with MedPage Today, researchers said: “Addition of denosumab to background methotrexate treatment has potential to be a new therapeutic option for patients with RA with risk factors for joint destruction. Shorter dosing interval regimens of densoumab showed a numerical trend for better inhibition of bone destruction, while significant differences among denosumab groups were not confirmed.”
Researchers also observed that all denosumab groups showed significantly increased BMD at the lumbar spine and total hip compared with the placebo group at 6 and 12 months, regardless of glucocorticoid use. They also indicated that there were no differences between the denosumab groups and placebo on American College of Rheumatology 20/50/70 response rates, disease activity score in 28 joints using C-reactive protein, or the Health Assessment Questionnaire Disability Index.
The authors noted that future studies on this topic should have a longer duration of treatment and include a larger number of patients.