Objective: The role of alternative tumor necrosis factor (TNF) antagonist therapies in the context of failure of initial TNF antagonist therapy in patients with rheumatoid arthritis (RA) has yet to be clearly defined. The goal of this study was to determine the efficacy of etanercept in patients who failed to respond to infliximab.
Methods: Ninety-five patients with RA who failed to respond to infliximab and methotrexate were treated with etanercept (with continuation of concomitant methotrexate). Thirty-four patients never achieved a response to infliximab (primary nonresponse), 38 had an initial response to infliximab but relapsed (secondary nonresponse), and 23 demonstrated toxicity. Disease Activity Score in 28 joints (DAS28), European League Against Rheumatism (EULAR) response, and American College of Rheumatology (ACR) response were determined after 12 weeks of etanercept.
Results: After 12 weeks of etanercept, 38% of patients achieved an ACR 20% response (ACR20) on etanercept. Of these, 24% and 15% achieved ACR50 and ACR70 responses, respectively. In the primary infliximab nonresponse group, 42%, 30%, and 15% achieved ACR20, ACR50, and ACR70 responses, respectively; the percentages for the secondary nonresponse group were 34%, 21%, and 14%, respectively. Significant DAS28 reductions were observed in the entire cohort and nonresponse subtype groups. Sixty-one percent of the cohort achieved either a moderate or good EULAR score (67% of primary and 56% of secondary infliximab failures). No toxicity was observed in patients who stopped infliximab due to intolerance; 19 of 23 continued etanercept after week 12.
Conclusion: This study confirms that etanercept is effective in patients who fail to respond to infliximab and suggests a higher response in patients who have never had a response to infliximab.