Background Rheumatoid arthritis (RA) is an autoimmune disease with involvement of small and large joints. Biologic agents (BAs) represent treatment options if disease is not adequately controlled by DMARDs. Prognostic factors that may predict good clinical response to treatment and long-term efficacy need to be identified in these patients.
Objectives To estimate the predictive value of early good response, after 3 months of biologic treatment, in long-term efficacy and the level of disease activity in patients with RA.
Methods This is a retrospective study of 1.494 patients' files (1.173 women and 321 men, mean age at disease initiation 48.9 years). Demographic and clinical data were recorded during every patient's visit. There were 355 patients with initiation of biologic treatment during their follow-up in our department. Patients with less than 12 months administration of their first BA were excluded from further analysis. Disease activity was classified by DAS-28 score at 3, 6 and 12 months of treatment. Effectiveness of BAs was analyzed, taken in to account the EULAR criteria for response to treatment.
Results Two hundred forty seven patients with more than 12 months therapy with BAs were included in this analysis. Patients with good response after 3 months of treatment (DAS-28 <3.2, >1.2 variation between initial and final DAS-28), compared to patients with inadequate response, were 5 times more likely to achieve satisfactory response (remission or low disease activity) after 1 year of BAs administration (OR=5.15, 95% CI 2.84-9.31, p-value <0.0001). After adjustment for sex, age, type of joints and presence of extra-articular manifestations, the probability for good response remained similar (OR=4.73, 95% CI 2.53-8.84, p-value <0.0001). Further analysis was performed separately in incident (n=121) and prevalent cases (n=126). In the first group, patients with good response after 3 months of treatment were 6 times more likely to have similar response after one year of BAs (OR=6.27, 95% CI 2.57-15.33, p-value <0.0001) and 5 times more likely after adjustment to the aforementioned factors (OR=4.92, 95% CI 1.91-12.68, p-value =0.001). In the second group of prevalent cases, the prognostic value of early good response to treatment was similar (OR=4.45, 95% CI 1.99-9.93, p-value <0.0001 and OR=5.05, 95% CI 2.08-12.27, p-value <0.0001 after adjustment respectively).
Conclusions Early good response after 3 months of BAs administration may adequately predict a satisfactory long-term efficacy of biologic treatment in patients with RA.
Disclosure of Interest None declared