Predictive factors for induction of remission in patients with active rheumatoid arthritis treated with tocilizumab in clinical practice.

Abstract

To identify predictors of early response to tocilizumab (TCZ) in patients with active rheumatoid arthritis (RA) seen in daily routine clinical practice. A multicenter ambispective observational study of 126 RA patients treated with TCZ as a first- or second-line biological therapy. The variables associated to achieve the therapeutic goal (remission defined as a DAS28-ESR < 2.6) at 3 and 6 months were identified using regression analysis. TCZ was administered as the first biologic in 26% of patients. Overall, 34% of patients received TCZ as monotherapy. EULAR response and remission were obtained in 82% and 31% of patients at 3 months and in 86% and 40% at 6 months. In the multivariate analysis, the predictive factors increasing the likelihood of clinical remission at 3 months were baseline ESR > 30 mm/h (OR = 19.07, 95% CI: 2.720-133.716), baseline CRP > 10 mg/L (OR = 4.95; 95% CI: 1.464-13.826), and the presence of extra-articular manifestations of the disease (OR = 15.45, 95% CI: 2.334-102.319). The factors that decreased it were higher concentrations of hemoglobin (OR = 0.53, 95% CI: 0.319-0.910), higher baseline DAS28-ESR (OR = 0.30, 95% CI: 0.145-0.635) and the number of previous DMARDs (OR = 0.41, 95% CI: 0.221-0.779), and biological therapies used (OR = 0.33, 95% CI: 0.155-0.734). The only factor that remained statistically significant at 6 months was higher baseline DAS28-ESR (OR = 0.55, 95% CI: 0.347-0.877). No relationship was found with the neutrophil count or with the RF or ACPA positivity. In routine clinical practice, strong acute phase response, the presence of extra-articular manifestations, and the number of previous DMARDs and biological therapies used may help to identify patients who will have a rapid response to TCZ. However, it is likely that no parameter will predict response if taken separately.