Efficacy and Safety of Celecoxib in Chinese Patients with Ankylosing Spondylitis: A 6-Week Randomized, Double-Blinded Study with 6-Week Open-Label Extension Treatment

BACKGROUND Nonsteroidal anti-inflammatory drugs are the first-line option for treating ankylosing spondylitis (AS) in China. However, no large-scale controlled trials have been conducted in this ethnic population. OBJECTIVE To evaluate the efficacy and safety of 6 weeks' treatment with celecoxib in patients with AS in China. METHODS This Phase 3, double-blind, parallel-group study randomized patients with AS aged ≥18 to 65 years 1:1 to receive celecoxib 200 mg once daily or diclofenac sustained release 75 mg once daily. After 6 weeks, patients could use celecoxib 400 mg once daily or maintain blinded therapy. The primary efficacy end point was mean change from baseline at Week 6 for Patient's Global Assessment of Pain Intensity score (100-mm visual analog scale). Noninferiority was established if the upper bound of the CI was <10 mm. Secondary objectives included patients' and physicians' assessments of disease activity, change from baseline in C-reactive protein level, and safety. RESULTS In the per-protocol analysis set the least squares mean change from baseline in the Patient's Global Assessment of Pain Intensity score at Week 6 was -23.8 mm and -27.1 mm in patients receiving celecoxib (n = 111) and diclofenac (n = 108), respectively. The 2-sided 95% CI for the treatment difference (celecoxib - diclofenac) was -2.2 to 8.8. Overall, 4.2% and 6.7% of patients in the celecoxib and diclofenac groups, respectively, reported treatment-related adverse events. All were mild to moderate in severity. CONCLUSIONS Celecoxib 200 mg once daily is noninferior to diclofenac sustained release 75 mg once daily for pain treatment in Chinese patients with AS. ClinicalTrials.gov identifier: NCT00762463.