Efficacy of tocilizumab monotherapy after response to combined tocilizumab and methotrexate in patients with rheumatoid arthritis: the randomised JUST-ACT study.

OBJECTIVES: The aim of the JUST-ACT study was to assess whether the add-on effect of tocilizumab (TCZ) to background methotrexate (MTX) observed in MTX-inadequate responders with active rheumatoid arthritis (RA), would be sustained when MTX is withdrawn. METHODS: A double-blind, parallel-group, phase 3 study in biologic-naïve RA patients with a disease activity score 28 (DAS28)>3.2 despite MTX which were treated with TCZ+MTX for an initial 16-week period. Patients who at week 16 achieved low disease activity (LDA) (DAS28≤3.2) were randomised to continue with TCZ+MTX or switch to TCZ + placebo (PBO) for an additional 12 weeks. The primary endpoint was the change in DAS28-ESR from the randomisation at week 16 to week 28. Non-inferiority was confirmed if the upper limit of the two-sided 95%CI for the treatment difference between TCZ+MTX and TCZ monotherapy groups was lower than the selected non-inferiority margin of 0.6. RESULTS: 261 patients completed the first 16 weeks of TCZ+MTX treatment and 165 were randomised (83 to TCZ+MTX and 82 to TCZ+PBO). For the primary endpoint, the adjusted treatment difference (95% CI) in mean change of DAS28-ESR was -0.06 (-0.40 to 0.27), and therefore the non-inferiority of switching to TCZ monotherapy versus continuing with TCZ+MTX was demonstrated. In both treatment groups, the percentage of patients in clinical remission from 16 to 28 weeks was similar as were the improvements in disease activity, functional disability and quality of life. CONCLUSIONS: In MTX non-responder patients achieving LDA with TCZ+MTX, switching to TCZ monotherapy is non-inferior to continuing the combination.

A Single Nucleotide Polymorphism in the Il17ra Promoter Is Associated with Functional Severity of Ankylosing Spondylitis.

The aim of this study was to identify new genetic variants associated with the severity of ankylosing spondylitis (AS). We sequenced the exome of eight patients diagnosed with AS, selected on the basis of the severity of their clinical parameters. We identified 27 variants in exons and regulatory regions. The contribution of candidate variants found to AS severity was validated by genotyping two Spanish cohorts consisting of 180 cases/300 controls and 419 cases/656 controls. Relationships of SNPs and clinical variables with the Bath Ankylosing Spondylitis Disease Activity and Functional Indices BASDAI and BASFI were analyzed. BASFI was standardized by adjusting for the duration of the disease since the appearance of the first symptoms. Refining the analysis of SNPs in the two cohorts, we found that the rs4819554 minor allele G in the promoter of the IL17RA gene was associated with AS (p<0.005). This variant was also associated with the BASFI score. Classifying AS patients by the severity of their functional status with respect to BASFI/disease duration of the 60th, 65th, 70th and 75th percentiles, we found the association increased from p60 to p75 (cohort 1: p<0.05 to p<0.01; cohort 2: p<0.01 to p<0.005). Our findings indicate a genetic role for the IL17/ILRA axis in the development of severe forms of AS.