Limited efficacy of conventional DMARDs after initial methotrexate failure in patients with recent onset rheumatoid arthritis treated according to the disease activity score

Abstract

Objectives: To determine the efficacy of subsequent disease modifying antirheumatic drug (DMARD) therapies after initial methotrexate (MTX) failure in patients with recent onset rheumatoid arthritis (RA), treated according to the DAS for 2 years.

Methods: In groups 1 and 2 of the BeSt study, 244 RA patients were initially treated with MTX 15-25 mg/week. Patients who discontinued MTX because of insufficient clinical response (disease activity score, DAS >2.4) or toxicity were classified as "MTX failures." In group 1, these patients switched to sulfasalazine (SSA), then leflunomide and finally to MTX + infliximab (IFX). In group 2, "MTX failures" added SSA to MTX, then hydroxychloroquine (HCQ), then prednisone, and eventually switched to MTX + IFX. "MTX successes" were patients who achieved a DAS </=2.4 after 2 years while still on MTX monotherapy. Total Sharp/van der Heijde score (TSS) progression from 0-2 years was assessed in "MTX failures" versus "MTX successes."

Results: After 2 years, 162/244 patients (66%) had discontinued MTX because of insufficient response or toxicity. Of these, 78% also failed on SSA (adding or switching), 87% subsequently failed on leflunomide (in group 1), and 64% on MTX + SSA + HCQ (in group 2). 34 of 48 patients (71%) in groups 1 and 2 were successfully treated with MTX + IFX. After 2 years, regardless of the "success" on subsequent DMARDs, " MTX failures" had a median TSS progression of 3 units (mean 9) versus 1 unit (mean 3) in "MTX successes" (p = 0.007).

Conclusion: After failure on initial MTX, treatment with subsequent conventional DMARDs is unlikely to result in a DAS </=2.4 and allows progression of joint damage.