Impact of denosumab discontinuation on changes in bone mineral density and bone erosion in rheumatoid arthritis patients.

OBJECTIVES This study investigated changes in bone mineral density (BMD) and erosion after denosumab discontinuation in rheumatoid arthritis (RA) patients without osteoporosis who participated in the DESIRABLE study. METHODS This multicentre observational study consisted of a prediscontinuation visit (date of final assessment in DESIRABLE) and a postdiscontinuation visit (2.5 years after the last administered dose of denosumab). Percentage change in lumbar spine (LS) BMD from baseline was assessed as the primary endpoint. RESULTS Fifty-nine patients were enrolled. The percentage change in LS BMD decreased to baseline levels at the postdiscontinuation visit. Compared with baseline, C-telopeptide of type I collagen levels increased after denosumab discontinuation but most patients had levels within the reference range. Bone erosion scores were not significantly different between the on-treatment period and after denosumab discontinuation (p = .0666) but there was a numerical increase postdiscontinuation. The progression in bone erosion score was significantly reduced in patients whose disease activity was in remission versus those not in remission (p = .0195). CONCLUSIONS In RA patients without osteoporosis, denosumab discontinuation can be explored while considering patient background factors (disease activity and risk of fracture) and accounting for progression of bone erosion and LS BMD decrease after withdrawal.