Long-term effectiveness of tocilizumab in patients with rheumatoid arthritis, stratified by number of previous treatment failures with biologic agents: results from the German RABBIT cohort

In Germany, Tocilizumab (TCZ) is used for the treatment of rheumatoid arthritis both in biologic-naïve patients and those with previous failures of biologic disease-modifying antirheumatic drugs (bDMARDs). The long-term effectiveness and retention rates of TCZ in patients with different numbers of prior bDMARD failures has rarely been investigated. We included 885 RA patients in the analyses, enrolled with the start of TCZ between 2009 and 2015 in the German biologics register RABBIT. Patients were stratified according to prior bDMARD failures: no prior bDMARD or 1, 2 or ≥ 3 bDMARD failures. We applied Kaplan–Meier methods and Cox-regression to examine treatment adherence as well as linear mixed effects models to investigate effectiveness over 3 years of follow-up. Compared to biologic-naïve patients, those with prior bDMARD failures at start of TCZ were younger but had significantly longer disease duration and more comorbidities. DAS28 at baseline and loss of physical function were highest in patients with ≥ 3 bDMARD failures. During follow-up, patients with up to two bDMARD failures on average reached low disease activity (LDA, DAS28 < 3.2). Those with ≥ 3 prior bDMARDs had a slightly lower response. However, after 3 years, nearly 50% of them achieved LDA. Treatment continuation on TCZ therapy was similar in patients with ≤ 2 bDMARD failures but significantly lower in those with ≥ 3 bDMARD failures. TCZ seems to be similarly effective in patients with no, one or two prior bDMARD failures. The majority of patients achieved LDA already after 6 months and maintained it over a period of 3 years. TCZ proved effective even in the high-risk group of patients with more than two prior bDMARD failures.