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.