Background/Purpose: Although anti-TNF therapies moved forward the treatment of rheumatoid arthritis (RA), failure of the first anti-TNF medication is not uncommon. Many times modifying dosage/frequency of the initial drug or prescribing a different TNF inhibitor proves to be still inadequate. Using instead a biologic with a different mechanism of action, such as Rituximab (RTX), may be beneficial in terms of RA treatment to target.

Based on EULAR-T2T and ACR criteria we analysed response following each RTX course (2 g at every 24 weeks).

Methods: Longitudinal (2002 to date), observational, population-based, cohort study. The analysis was performed based on data from the National Health Insurance House (NHIH) for 400 out of 1126 patients treated with RTX for RA in October 2011 in the NHIH database. The patients’ selection is statistically representative and homogenous at national level. All patients had an anti-TNF medication as first treatment stage for 2.5 years (average). In the second stage, 208 patients were switched to RTX after the initial anti-TNF failure. The remaining 192 patients followed one or two more anti-TNF therapy and only then continued with RTX. A total of 5 RTX courses were administered to both groups. Before each RTX course patient were monitored for DAS28 and EULAR response.

Results: Average DAS28 before RTX was 6.7 (N=400), reaching 4.5 (before C2), then 3.41 (before C3).  At the time of this analysis 335 patients followed C3 and 211 C4. Before RTX start, 93% of the total number of patients was in HDA and 8% in MDA. After 2 RTX courses 38.25 % of the patients reached LDA or remission. After 18 months (before C4) 63.88 % patients were in LDA or remission, while before C5 86.73% of the 211 patients having C4 were in LDA or remission (48.82% in remission). In terms of EULAR response after 4 RTX cycles 84.36% had a good response and 15.64% a moderate response, compared to previous treatment with anti-TNF in the same interval (2 years): 5.03% good response and 91.82% moderate response.

 Conclusion: Each RTX course led to an increased and cumulative clinical DAS28 response compared to the previous one. With each following RTX course all patients registered consolidation of lower DAS28 response, and continuously growing LDA or remission percentage. Response was sustained and cumulated regardless their rheumatoid factor status. Introducing Rituximab to patients with no response or intolerance to anti-TNF agents proved to be an adequate choice, therefore we consider its prescription after the first anti-TNF failure as a preferred option in terms of clinical response.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/sustained-and-cumulated-response-over-time-in-rheumatoid-arthritis-patients-treated-with-rituximab-after-initial-failure-of-anti-tumor-necrosis-factor-agents/