Background/Purpose: Recently, we showed that treatment with COBRA-light therapy including prednisone with initially 30 mg/day, was as effective as the original COBRA scheme, with initially 60 mg/day [1], in the treatment of rheumatoid arthritis (RA). Since high-dose glucocorticoids are associated with bone loss, we investigated the differences in bone mineral density (BMD) after one year of treatment in both arms. Therefore, this study aims to determine whether there is a significant difference in BMD between COBRA and COBRA-light, and to determine the difference in change in BMD between baseline and 52 weeks between these groups, at the lumbar spine (L1-L4), total hip, and femoral neck.  

Methods: An open-label, randomised controlled, non-inferiority trial of patients with active, newly diagnosed RA following a treat-to-target protocol.  

Results: BMD data were determined in 144 out of 164 included RA patients, all randomized to either COBRA (n=71) or COBRA-light (n=73) therapy. Both at baseline and after 52 weeks, no significant difference in BMD was found between COBRA and COBRA-light, at all sites. Changes between baseline and week 52 are shown in Table 1. No significant difference in change in BMD between COBRA and COBRA-light was found, at all sites. However, COBRA-light showed a significant decrease in BMD in the lumbar spine and total hip after 52 weeks, whereas the femoral neck and the COBRA group did not.  

Conclusion: No difference in change in BMD between COBRA and COBRA-light was found. The overall bone loss was small, which suggests that the negative effects of (high-dose) prednisone on bone might be counteracted by the large reduction in disease activity as a result of combination therapy and tight control treatment.         References: [1] Ter Wee MM, et al. Ann Rheum Dis 2015.