Despite the demonstrated efficacy of etanercept for the treatment of ankylosing spondylitis (AS), sulfasalazine is often prescribed, especially in countries with limited access to biologic agents. The objective of this subset analysis of the ASCEND trial was to compare the efficacy of etanercept and sulfasalazine in treating patients with AS from Asia, Eastern/Central Europe, and Latin America. A total of 287 patients, 190 receiving etanercept 50 mg once weekly and 97 receiving sulfasalazine 3 g daily, from eight countries were included in this subset analysis. Differences in disease activity and patient-reported outcomes assessing health-related quality-of-life (HRQoL) parameters in response to treatment were analyzed using the Cochran-Mantel-Haenszel test for categorical efficacy endpoints and analysis of covariance model for continuous variables. At week 16, a significantly greater proportion of patients receiving etanercept achieved ASAS20 (79.0 %) compared with patients receiving sulfasalazine (61.9 %; p = 0.002). At week 16, treatment with etanercept also resulted in significantly better responses than sulfasalazine for ASAS40 (64.7 vs. 35.1 %; p < 0.001), ASAS5/6 (48.1 vs. 26.3 %; p < 0.001), proportion of patients achieving 50 % response in Bath AS Disease Activity Index (65.8 vs. 42.3 %; p < 0.001), partial remission (35.3 vs. 17.5 %; p = 0.002), and all HRQoL parameters. Both treatments were well tolerated. Etanercept was significantly more effective than sulfasalazine in the treatment of patients with AS from Asia, Central/Eastern Europe, and Latin America.
Keywords: Ankylosing spondylitis; Efficacy; Etanercept; HRQoL; Subset analysis.