A Multi-Biomarker Disease Activity Score and the Choice of Second-Line Therapy in Early Rheumatoid Arthritis After Methotrexate Failure

Objective: To investigate whether the Multi-Biomarker Disease Activity (MBDA) score predicts optimal add-on treatment in patients with early rheumatoid arthritis (RA) who were inadequate responders to MTX (MTX-IRs). Methods: We analyzed data from 157 MTX-IRs (with a Disease Activity Score using the erythrocyte sedimentation rate [DAS28-ESR] >3.2) from the Swedish Pharmacotherapy (SWEFOT) trial who were randomized to receive triple therapy (MTX plus sulfasalazine plus hydroxychloroquine) versus MTX plus infliximab. The MBDA score as a predictor of the subsequent DAS28-based response to each second-line treatment was analyzed at randomization with the Breslow-Day test for 2 × 2 groups, using both validated categories (low [<30], moderate [30–44], and high [>44]) and dichotomized categories (lower [≤38] versus higher [>38]). Results: Among the 157 patients, 12% had a low MBDA score, 32% moderate, and 56% high. Of those with a low MBDA score, 88% responded to subsequent triple therapy, and 18% responded to MTX plus infliximab (P = 0.006); for those with a high MBDA score, the response rates were 35% and 58%, respectively (P = 0.040). When using 38 as a cutoff for the MBDA score (29% patients with lower scores versus 71% with higher scores), the differential associations with response to triple therapy versus MTX plus infliximab were 79% versus 44% and 36% versus 58%, respectively (P = 0.001). Clinical and inflammatory markers had poorer predictive capacity for response to triple therapy or MTX plus infliximab. Conclusion: In patients with RA who had an inadequate response to MTX, the MBDA score categories were differentially associated with response to subsequent therapies. Thus, patients with post-MTX biochemical improvements (lower MBDA scores) were more likely to respond to triple therapy than to MTX plus infliximab. If confirmed, these results may help to improve treatment in RA.