Infection outcomes in patients with rheumatoid arthritis treated with abatacept and other disease-modifying antirheumatic drugs: Results from a 10-year international post-marketing study.

Objective: To evaluate risk of infections requiring hospitalization and opportunistic infections, including tuberculosis, in patients with rheumatoid arthritis (RA) treated with abatacept versus conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) and other biologic/targeted synthetic (b/ts) DMARDs.

Methods: Five international observational data sources were used: two biologic registries (Sweden, Germany), a disease registry (USA) and two healthcare claims databases (Canada, USA). Crude incidence rates (IRs) per 1000 patient-years, with 95 % CIs, were used to estimate rate ratios (RRs) comparing abatacept versus csDMARDs or other b/tsDMARDs. RRs were adjusted for demographic factors, comorbidities, and other potential confounders and then pooled across data sources using a random effects model (REM).

Results: The data sources included 6450 abatacept users, 136,636 csDMARD users and 54,378 other b/tsDMARD users, with a mean follow-up range of 2.2-6.2 years. Across data sources, the IRs for infections requiring hospitalization ranged from 16 to 56 for abatacept, 19-46 for csDMARDs, and 18-40 for other b/tsDMARDs. IRs for opportunistic infections were 0.4-7.8, 0.3-4.3, and 0.5-3.8; IRs for tuberculosis were 0.0-8.4, 0.0-6.0, and 0.0-6.3, respectively. The pooled adjusted RR (95 % CI), only reported for infections requiring hospitalization, was 1.2 (0.6-2.2) for abatacept versus csDMARDs and 0.9 (0.6-1.3) versus other b/tsDMARDs.

Conclusions: Data from this international, observational study showed similar hospitalized infection risk for abatacept versus csDMARDs or other b/tsDMARDs. IRs for opportunistic infections, including tuberculosis, were low. These data are consistent with the known safety profile of abatacept.