Evaluation of the efficacy of etoricoxib in ankylosing spondylitis: results of a fifty-two-week, randomized, controlled study

Abstract

Objective: To assess the efficacy, safety, and tolerability of etoricoxib, a cyclooxygenase 2 (COX-2) selective inhibitor, administered continuously over 52 weeks for the treatment of ankylosing spondylitis (AS).

Methods: This 2-part, multicenter, double-blind, parallel-group, 52-week study evaluated 2 doses of etoricoxib (90 and 120 mg) compared with naproxen at 1,000 mg. A 6-week, active-comparator- and placebo-controlled period (part I) was followed by a 46-week active-comparator-controlled period (part II). The primary outcome measures (on 100-mm visual analog scales) were patient's assessment of spine pain, patient's global assessment of disease activity, and the Bath Ankylosing Spondylitis Functional Index.

Results: Of the 387 patients randomized to receive treatment, 301 (77.8%) completed part I and 284 (75.9%) completed part II. Compared with placebo over 6 weeks, those receiving 90 mg etoricoxib, 120 mg etoricoxib, and naproxen demonstrated significantly (P < 0.001) greater improvement in all primary end points; treatment effects (expressed as the difference in least squares mean change versus placebo) were 21-29 mm for spine pain, 18-25 mm for disease activity, and 11-15 mm for function. Compared with patients receiving naproxen, significantly greater improvement in all primary end points was demonstrated in the combined group receiving either 90 mg etoricoxib or 120 mg etoricoxib over 6 weeks, in each individual etoricoxib treatment group over 6 weeks, and in the combined etoricoxib group over 1 year (all P < 0.05); results for secondary and exploratory end points were generally consistent with those from the primary analysis. Among all groups, there were no significant differences in the incidence of overall clinical, drug-related, or serious adverse experiences (AEs) and discontinuations due to AEs. Safety observations during part II were generally consistent with those in part I.

Conclusion: Etoricoxib at doses of 90 mg and 120 mg demonstrated superior efficacy compared with placebo over 6 weeks, and compared with naproxen over 1 year. These study results demonstrate that etoricoxib is generally safe, well-tolerated, and efficacious for the treatment of AS.