Efficacy of leflunomide addition in relation to prognostic factors for patients with active early rheumatoid arthritis failing to methotrexate in daily practice

The recommendations of the European League Against Rheumatism (EULAR) for the management of rheumatoid arthritis (RA) suggest a different therapeutic approach to methotrexate (MTX) resistance according to the presence or absence of poor prognostic factors. Retrospectively, in our patients with active early RA (disease activity score in 28 joints (DAS28)>3.2) that failed to respond to initial MTX monotherapy, we investigated whether leflunomide (LEF) addition had a different efficacy when associated with the presence or absence of poor prognostic factors. Of the 20 patients who received LEF, 15 (2 males and 13 females) tolerated the combination. Five patients had no poor prognostic factors, and 4 (80%) of those patients achieved remission or low disease activity (LDA) according to DAS28 and also a good response with the EULAR criteria. Of the 10 patients with at least one poor prognostic factor, remission or LDA occurred in 4 (40%) of the patients, and a good EULAR response was obtained in 3 (30%) of the patients. By Fisher's exact test, no significant difference was found between the two groups of patients in remission or LDA (p=0.28) according to DAS28 and a good response (p=0.12) with the EULAR criteria. In all patients with an inadequate response to the LEF+MTX combination, the substitution of a TNF inhibitor for LEF or the addition of a TNF inhibitor to the combination led to remission or LDA. Large studies are required to investigate the efficacy of LEF addition in relation to prognostic factors in patients with active early RA that did not respond to the initial therapy with MTX alone.