Denosumab significantly improves bone mineral density with or without bisphosphonate pre-treatment in osteoporosis with rheumatoid arthritis Denosumab improves bone mineral density in osteoporosis with rheumatoid arthritis

Bone mineral density (BMD) sometimes cannot be improved by long-term bisphosphonate (BP) therapy in osteoporosis (OP) patients with rheumatoid arthritis (RA). This study showed that BMD significantly increased after denosumab treatment in patients with long-term BP pre-treatment as much as in treatment-naive patients. Thus, denosumab can be a strong OP treatment option for long-term BP pre-treated RA patients. Introduction The aim of this 24-month retrospective study was to evaluate differences in outcomes of denosumab with or without bisphosphonate (BP) pre-treatment in osteoporosis (OP) patients with rheumatoid arthritis (RA). Methods Patients were divided into those with (BP group, 26 cases) or without (denosumab group, 26 cases) BP pre-treatment. We measured serum BAP, TRACP-5b, and urinary NTX at baseline and every 3 months for 24 months. We also assessed bone mineral density (BMD) of the lumbar 1-4 vertebrae (L-BMD) and total hip BMD (H-BMD) at baseline and every 6 months for 24 months. MMP-3, DAS28-CRP, SDAI, and HAQ-DI were assessed at baseline and 24 months to evaluate RA state. Results In BP group, the percent changes of bone turnover markers decreased but were consistently higher compared with those in the denosumab group. There were significant differences of the percent changes in BAP at 9, 21, and 24 months; TRACP-5b at 9, 18, and 21 months; and urinary NTX at 3, 9, 12, 15, 18, and 21 months between the groups. The percent changes of L-BMD and H-BMD were significantly increased at 24 months in the BP pre-treated group (11.5 and 13.3%, respectively) and denosumab group (13.0 and 16.5%, respectively). There was a significant difference of the percent changes in H-BMD at 6 months between the groups. There was no significant difference in RA state between the groups. Conclusions Compared with BP group, denosumab group displayed significantly increased H-BMD at 6 months, while L-BMD and H-BMD were significantly increased for 24 months in both groups. Thus, regardless of BP pre-treatment, denosumab could be a good agent in OP with RA.