RESUMO
OBJECTIVES: To evaluate the influence of anti-infliximab antibodies (anti-IFX) on 3 different points of care: response/tolerance to infliximab (IFX), tapering strategy, and in a subsequent treatment with a second tumor necrosis factor inhibitor (TNFi). METHODS: A prospective cohort of 60 radiographic axial spondyloarthritis (r-axSpA) patients under IFX were evaluated retrospectively regarding clinical/laboratorial data, IFX levels and anti-IFX, at baseline, after 6, 12-14, 22-24, 48-54, 96-102 weeks and before tapering or switching. RESULTS: Anti-IFX were detected in 27 (45%) patients, of whom 23 (85.1%) became positive in the first year of IFX treatment. In comparison to negative anti-IFX group, anti-IFX positive patients demonstrated the following: less use of methotrexate (MTX) as a concomitant treatment to IFX (5 [18.5%] vs. 14 [42.4%]; p=0.048); more infusion reactions at 22-24 weeks (p=0.020) and 48-54 weeks (p=0.034); more treatment failures (p=0.028) at 48-54 weeks; reduced overall IFX survival (p<0.001); and lower sustained responses (p=0.044). Of note, positive anti-IFX patients exhibited a shorter tapering survival (9.9 months [95% CI 4.0-15.8] vs 63.4 months [95% CI 27.9-98.8]; p=0.004) in comparison with negative anti-IFX patients. Conversely, for patients who failed IFX, positive anti-IFX patients had better clinical response to the second TNFi at 3 (15 [83.3%] vs. 3 [27.3%]; p=0.005) and 6 months (15 [83.3%] vs. 4 [36.4%]; p=0.017) than the negative anti-IFX patients after switching. CONCLUSIONS: This study provided novel data that anti-IFX is a parameter for reduced tapering survival, reinforcing its detection to guide clinical decision. Additionally, we confirmed in a long-term cohort the anti-IFX association with worse IFX performance and as predictor of 2nd TNFi good clinical response.
