AB0231 OUTCOMES IN RHEUMATOID ARTHRITIS PATIENTS UNDER TOCILIZUMAB AS FIRST bDMARD: A REAL-LIFE MONOCENTRIC COHORT STUDY
Authors: F. R. Martins, A. Martins, D. Santos Oliveira, D. Fonseca, M. Rato, F. Oliveira Pinheiro, S. Garcia, B. M. Fernandes, L. Costa, M. Bernardes
Journal: Annals of the Rheumatic Diseases (2021)

Background: Rheumatoid arthritis (RA) is one of the most frequent systemic inflammatory rheumatic diseases, being constantly assessed regarding new disease activity monitoring tools and new therapeutic targets and therapies. Tocilizumab (TCZ) is one of the latest biological disease-modifying antirheumatic drugs (bDMARDs) approved for RA’s treatment, usually as a second line agent in daily clinical practice. Objectives: Evaluate the different disease and patient reported outcomes in patients undergoing treatment with tocilizumab as the first biologic therapy. Methods: All patients with a definite RA diagnosis who had undergone treatment with TCZ as the first biologic therapy at a tertiary hospital’s rheumatology department were included in this analysis. Diverse socio-demographic data, as well as disease and patient related outcomes were assessed at baseline, 6 and 12 months of treatment with TCZ, and posteriorly extracted from the Portuguese register of rheumatic diseases (Reuma.PT). Statistical analysis included non-parametric tests such as Wilcoxon test and univariate analysis using linear and logistic regression models. Results: Fifty-one patients were included, 88.2% females, with a median age at introduction of TCZ of 53.5 +/- 10.4 years; mainly seropositive for either rheumatoid factor (66%) or anti citrullinated peptide antibody (ACPA; 68%), with an erosive disease (75.6%) and concomitantly treated with a conventional synthetic disease modifying anti-rheumatic drug (csDMARD) (70.5%). During follow-up there was a statistically significant reduction at 6 and 12 months of TCZ treatment regarding DAS28 (4 variables) (4v) and DAS28(4V)-CRP scores (p &lt; 0.001), SDAI (p &lt; 0.001), CDAI (p &lt; 0.001), 68/66 tender and swollen joint counts (TJC/SJC) (p &lt; 0.001), ESR and CRP (p &lt; 0.001), patient and physician VAS (p &lt; 0.001) and HAQ score (p = 0.01 at 6 months and p &lt; 0.001 at 12 months). Rheumatoid factor and ACPA serum levels weren’t statistically different at 6 and 12 months of treatment with TCZ compared to the initial assessment, as well as the ACR responders at the same 6 months versus those at 12 months. A majority of patients showed good EULAR response at 6 (52.6%) and 12 (56.3%) months, as well as moderate to high mean improvement in ACR core set measures at 6 (53.3±22.7) and 12 (54.3±25.2) months. Assessment of subsequent therapeutic maintenance showed that 75% of patients remained under tocilizumab with an average treatment duration of 48.8±37.7 months. Reasons for switch ranged from adverse effects (63.6%) to primary failure (18.2%) and secondary failure (18.2%). There was a significant reduction in DAS28(4V), DAS28(4V)-CRP, CDAI, SDAI, TJC and SJC, ESR, CRP, patient and physician VAS and HAQ scores between 6 and 12 months of therapy (p &lt; 0,001). ACR and EULAR responses didn’t differ significantly between assessments at 6 and 12 months. In the absence of a representative number of RA patients on TCZ monotherapy, it wasn’t possible to draw conclusions about the need to use combined therapy with a csDMARD for better clinically significant response. A higher degree of ACR response at 6 months was associated with higher serum rheumatoid factor levels (OR 1.13, p &lt; 0.05) at baseline, while a lower degree of response was seen with higher TJC (p = 0.05) and HAQ score (p &lt; 0.01). ACR response at 12 months was lower in patients with erosive disease at baseline (p &lt; 0.05). Regarding EULAR response criteria at 6 months, there was a negative association with higher TJC (p &lt; 0.05), while at 12 months the negative trend was associated with ESR levels (p &lt; 0.05) and HAQ scores (p &lt; 0.05) at baseline. Conclusion: There seems to be evidence of good therapeutic response to TCZ in bDMARD naïve RA patients assessed at 6 months from baseline, without evidence of significant improvement of response measures further down the line. Basal serum rheumatoid factor levels, TJC, HAQ scores and the presence of erosive disease may have some predictive value on the therapeutic response. Further studies comparing TCZ as the first bDMARD in naïve RA patients against TNF inhibitors are needed. Disclosure of Interests: None declared