Key clinical point: Tumor necrosis factor inhibitors (TNFis) vs. abatacept or tocilizumab showed no significant difference in the risk for osteoporotic fractures among patients with rheumatoid arthritis (RA).
Major finding: No significant difference was observed in the risk for osteoporotic fractures between patients initiating TNFis vs. abatacept (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.48-1.71) or tocilizumab (HR, 1.00; 95% CI, 0.55-1.83).
Study details: The data come from a population-based cohort study of RA patients. A total of 2,307 TNFi initiators were matched with 588 abatacept initiators and 2,462 TNFi initiators were matched with 640 tocilizumab initiators.
Disclosures: This study was supported by a grant from Celltrion Healthcare company and the Hanmi Pharmaceutical company. The authors declared no conflicts of interest.
“Osteoporosis is common in patients with rheumatoid arthritis and is associated with 25% increased risk of fracture compared to general population. Because biologic disease modifying anti-rheumatic drugs (bDMARDs) suppress inflammation, they have been associated with decreased bone loss. However, the comparative effectiveness of various bDMARDs on decreasing the risk of osteoporotic fractures has not been studied. Using administrative data from patients with RA from Korea, the investigators compared the effect of TNFi vs abatacept, or TNFi vs tocilizumab on the occurrence of osteoporotic fractures. To adjust for > 50 baseline confounders, the study used propensity score (PS) matching with a variable ratio up to 10 TNFi initiators per 1 comparator drug initiator. A total of 2,307 TNFi initiators were matched with 588 abatacept initiators and 2,462 TNFi initiators were matched with 640 tocilizumab initiators. Importantly, only half of the patients had a diagnosis of osteoporosis.
The mean follow-up (± standard deviation, SD) was 457 ± 333 days for TNFi initiators and 441 ± 318 days for abatacept initiators (TNFis versus abatacept), and 466 ± 339 days for TNFi initiators and 439 ± 320 days for tocilizumab initiators (TNFis versus tocilizumab). There was no significant difference in the risk of osteoporotic fractures between patients initiating TNFi compared to abatacept, between those initiating TNFi compared to tocilizumab. Despite propensity score matching, residual confounding is possible and the number of people in the comparator groups were relatively small, which may have precluded observing a difference between groups.”
Maria I. Danila, MD, MSc, MSPH
University of Alabama at Birmingham
Shin A et al. 2020 Jun 8. Osteoporos Int. 2020 Jun 8. doi:10.1007/s00198-020-05488-9.