Response to etanercept for rheumatoid arthritis can be predicted by 12 weeks
Decision trees specifically designed for patients with rheumatoid arthritis for whom etanercept with or without methotrexate is newly prescribed now permit researchers to determine in which patients treatment efficacy can be predicted with confidence after only 12 weeks. These classification and regression trees also identify those patients in whom the likelihood of achieving low disease activity (LDA) within 1 year of this therapy is indeterminate after only 12 weeks on that regimen. Data for this study were taken from the Trial of Etanercept and Methotrexate with Radiographic Patient Outcomes (TEMPO).
Patients in this trial received 25 mg of etanercept twice a week; methotrexate from 7.5 to 20 mg once a week, depending upon persistence of joint pain or swelling; or both drugs. The researchers developed various decision trees to predict by week 12 whether LDA would be achieved at the end of 1 year of therapy. Some 39 percent of patients receiving etanercept alone and 60 percent of patients receiving etanercept plus methotrexate achieved LDA at week 52. At week 12, 53 percent of patients receiving etanercept were predicted to achieve LDA, while another 39 percent were predicted not to do so.
Among patients prescribed etanercept plus methotrexate, 63 percent were predicted to achieve LDA and 25 percent were predicted not to respond. As a result, within 12 weeks of initiating etanercept with or without methotrexate, success or failure in achieving an outcome of LDA at 52 weeks could be predicted in 80 to 90 percent of patients. The remaining 10 to 20 percent of patients required more time on therapy to establish whether they would respond adequately or should discontinue this treatment. The study was supported in part by the Agency for Healthcare Research and Quality (HS18517).
See "Predicting low disease activity and remission using early treatment response to antitumour necrosis factor therapy in patients with rheumatoid arthritis: Exploratory analyses from the TEMPO trial," by Jeffrey R. Curtis, M.D., M.P.H., Shuo Yang, Lang Chen, M.D., and others in the Annals of Rheumatology Diseases 71, pp. 206-212, 2012.