Achievement rate and predictive factors of the recommended therapeutical target in patients with axial spondyloarthritis who remain on biological therapy: a prospective cohort study in Spain.

OBJECTIVES: To determine the frequency of sustained remission (R) or low diseas activity (LDA) in patients with axial spondyloarthritis (axSpA) undergoing long-term biological therapy and to analyse predictive factors for achieving these outcomes. DESIGN: Prospective, observational cohort study. SETTING: Spanish hospital. PARTICIPANTS: Patients with axSpA who initiated biological treatment between 2003 and 2017. INTERVENTION: Assessment of demographic and clinical characteristics at the beginning of treatment and disease activity every 6 months up to a maximum of 2 years. MAIN OUTCOME MEASURES: Disease activity was measured by Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Disease Activity Index and C reactive protein (BASDAI&CRP). Sustained R was defined as ASDAS<1.3 and/or BASDAI <2 and normal CRP while sustained LDA was defined as ASDAS <2.1 and/or BASDAI <4 and normal CRP on at least three consecutive visits. RESULTS: In total 186 patients (66.1% men and 75.3% with radiographic sacroiliitis) were included. Overall, 76.8% of patients achieved ASDAS R/LDA (R53.2%/LDA23.6%) in at least one visit. Forty per cent (R17.6%/LDA22.4%) of the patients fulfilled the sustained ASDAS R/LDA state, whereas only 30.8% maintained this status (R14.8%/LDA15.9%) according to BASDAI&CRP. In the multivariate analysis, male sex (OR=4.01), younger age at the beginning of biological therapy (OR=0.96) and an HLA*B27 positive status (OR=4.30) were associated with achieving sustained ASDAS R/LDA. CONCLUSIONS: In clinical practice, around one-third of patients on biological disease-modifying antirheumatic drugs achieve a sustained R/LDA status, but these rates drop to less than one in five when targeting remission, preventing the use of the latter as a feasible target. Male sex, HLA*B27 positivity and younger age at the beginning of biological therapy are the main predictors for achieving sustained R/LDA.

Comparison of long-term efficacy between biological agents following tumor necrosis factor inhibitor failure in patients with rheumatoid arthritis: a prospective cohort study.

BACKGROUND: Currently, there is contradictory evidence regarding the best strategy to follow after discontinuation of a first biological agent in patients with rheumatoid arthritis (RA). We aimed to compare the long-term efficacy of switching to a second tumor necrosis factor inhibitor (TNFi) versus biopharmaceuticals with other mechanisms of action (non-TNFi) in patients with RA who previously failed a first TNFi. METHODS: This prospective cohort study analyzed data from 127 patients who discontinued a previous TNFi between 1999 and 2016. Disease activity was assessed at baseline and at 6, 12, and 24 months (m-6, m-12, m-24) after switching. Primary outcome was the proportion of patients achieving good/moderate EULAR response (E-resp). Factors associated with clinical outcomes were assessed using univariate and multivariate logistic regression models. RESULTS: Seventy-seven (61%) patients received a second TNFi and 50 (39%) switched to a non-TNFi. At m-6 and m-12, no differences were observed between groups; nevertheless, at m-24, the proportion of patients with E-resp was higher in the non-TNFi group (49% TNFi group versus 77% non-TNFi group; p = 0.002). In regression models, switching to a non-TNFi was significantly associated with E-resp at m-24 (odds ratio = 3.21; p = 0.01). When assessing the response to the second biological agent based on the reason for discontinuation of the first TNFi, similar results were obtained; at m-24, patients who discontinued the first TNFi due to inefficacy (either primary or secondary) experienced a better E-resp if they had switched to a non-TNFi (primary inefficacy: 52% TNFi group versus 79% non-TNFi group, p = 0.09; secondary inefficacy: 50% versus 76%, p = 0.03). CONCLUSION: In our cohort of RA patients who discontinued a first TNFi, those who switched to a non-TNFi were three times more likely to attain a sustained clinical response, regardless of whether they had discontinued the first biologic due to a primary or secondary inefficacy.