Abstract
OBJECTIVES: The aim of this study was to examine the discontinuation and occurrence of fracture during denosumab treatment in Japanese women with primary osteoporosis or rheumatoid arthritis (RA) with osteoporosis. METHODS: This retrospective study included 143 patients with primary osteoporosis and 96 patients with RA and osteoporosis who were treated with denosumab. Treatment discontinuation, fracture occurrence, lumbar spine (L1-4) bone mineral density (LS-BMD), and bilateral total hip BMD (TH-BMD) were examined before and at 1 and 2 years after treatment commencement. RESULTS: In the primary osteoporosis group, 32 cases dropped out and no fractures occurred from 0 to 1 year. Eighteen cases were lost to follow-up and no fractures were noted from 1 to 2 years. In the RA with osteoporosis group, 7 cases dropped out and no fracture occurred from 0 to 1 year. Twenty-one cases were lost to follow-up and 2 nonvertebral fractures were noted from 1 to 2 years. In this group, 13 cases dropped out from 1 to 2 years and 16 cases dropped out during the 2-year study period due to economic reasons. LS-BMD and TH-BMD values increased continuously for 2 years of treatment in both primary osteoporosis and RA with osteoporosis groups. CONCLUSIONS: These results suggest that during denosumab therapy, the discontinuation rate is expected to remain low during 2 years of treatment in primary osteoporotic patients. In RA patients with osteoporosis, however, the discontinuation rate may increase due to economic reasons from 1 to 2 years of therapy.