Background Although medication of rheumatoid arthritis (RA) has been improved by early intensive treatment using csDMARDs, tsDMARDs and bDMARDs for decades, treatment of concomitant disease in RA patients, such as osteoporosis (OP), will be more important to improve activity of daily living of RA patients. Although denosumab (DMB), an anti-RANKL antibody, was approved for treatment of OP in Japan in 2013, clinical data in real world is lacking in patients with RA. We reported 12 months efficacy of denosumab on osteoporosis in patients with RA at EULAR 2016 in London 1). Here we report results for 24 months.
Objectives To investigate the 24 months efficacy of denosumab (DMB) on osteoporosis in patients with rheumatoid arthritis (RA-OP) and to explore predictors of efficacy from multicenter study (TBCR-BONE).
Methods 59 female cases with RA-OP treated with DMB for 24 months were included in this study. Bone mineral density (BMD) of lumbar spine (LS-BMD) and total hip (TH-BMD) and serum bone turnover markers (P1NP and TRACP-5b) were measured at baseline and every 6 month until 24 months. Spearman's rank correlation coefficient was calculated between %increase of BMD at 24 months and various data (baseline patients' characteristics, parameters of RA disease activity [DAS28-CRP, SDAI, CRP, MMP-3] and bone turnover markers (BTMs) [P1NP and TRACP-5b]). Time averaged data (ta-data) which was averaged data of every 6 month was utilized for analysis with respect to data of RA disease activity and BTMs besides baseline data.
Results Mean age was 59 years old. Mean RA duration was 16 years. Rates of concomitant prednisolone use was 33.9%. Mean DAS28-CRP was 2.7. 44% of cases had the past history of fracture. Mean FRAX was 28%. Daly teriparatide was used in 11 cases before DMB treatment. %increase of LSBMD at every 6 month was significantly increased (4.7%>6.7%>7.7%>8.3%) and %increase of THBMD at every 6 month was significantly increased (2.9%>3.3%>4.9%>4.9%) (Fig1). %decrease of P1NP and TRACP-5b was 37.4%>33.8%>25.5%>26.0% and 33.3%>29.8%>26.1%>23.1%, respectively (Fig2). Fig3 showed that parameters (correlation coefficient) which were correlated with %increase of LSBMD at 24 months were %increase of LSBMD at 6 months (0.61), baseline P1NP (0.33) and time averaged %decrease of TRACP-5b (0.30). Parameters (correlation coefficient) which were correlated with %increase of THBMD at 24 months were %increase of LSBMD at 6 months (0.42), %increase of THBMD at 6 months (0.69), baseline P1NP (0.36), time averaged %decrease of P1NP (0.37), baseline TRACP-5b (0.29) and time averaged %decrease of TRACP-5b (0.29). Although %increase of BMD at 24 months was not correlated with disease activity of RA, taCRP was significantly correlated with taP1NP (0.57) and taTRACP-5b (0.45).
Conclusions DMB was effective in RA-OP. Early response of BMD, baseline values of BTMs and response of BTMs were suggested to be the predictors of the efficacy of DMB in RA-OP. Inflamation of RA was correlated with not BMD but BTMs.
Hirano Y et al. The predictors for 12 months efficacy of denosumab, an anti-RANKL antibody, on osteoporosis in patients with rheumatoid arthritis from multicenter study (TBCR-BONE). Ann Rheum Dis2016; 75(Suppl2): 94.
Disclosure of Interest None declared