Comparative effectiveness of abatacept, rituximab, tocilizumab and TNFi biologics in RA: results from the nationwide Swedish register.

Objectives: Current guidelines rank abatacept, rituximab, tocilizumab and TNF-inhibitors (TNFi) as having equal effectiveness for the treatment of RA, at least as second line therapies. These recommendations are mainly based on meta-analysis of randomized controlled trials, with few direct drug-drug comparisons. Our objective was to compare the real-world absolute and relative effectiveness among RA patients starting any of the available biologic DMARDs (bDMARDs).

Methods: We used the Swedish Rheumatology Register to identify patients with RA initiating TNFi, rituximab, abatacept or tocilizumab in 2010-2016 as first bDMARD (n = 9333), or after switch from TNFi as first bDMARD (n = 3941). National Swedish registers provided additional covariates and censoring events. Effectiveness was assessed 3 and 12 months after treatment start, as the proportion remaining on therapy and with EULAR Good Response, HAQ improvement >0.2, zero swollen/tender joints and CDAI remission. Adjusted differences were estimated with multivariable linear regression.

Results: Patients starting non-TNFi (vs TNFi) as first bDMARD had a higher proportion remaining on drug and reaching most response outcomes as first bDMARD (1-year EULAR Good Response/HAQ improvement: TNFi 24.9/25.4%, rituximab 28.6/37.2%, abatacept 31.9/33.7%, tocilizumab 50.9/43.1%). After switch from a first TNFi, rituximab and tocilizumab, but not abatacept, were associated with significantly better response measures than TNFi (1-year EULAR Good Response/HAQ improvement: TNFi 11.6/16.1%, rituximab 24.8/33.2%, abatacept 13.1/17.5%, tocilizumab 34.1/29.4%). Differences remained significant after adjusting for potential confounders.

Conclusion: Treatment outcomes among RA patients treated in Swedish clinical practice are in line with a superior effectiveness of non-TNFi bDMARDs, in particular tocilizumab and rituximab, compared with TNFi.