A comparison of the efficacy and safety of celecoxib 200 mg and celecoxib 400 mg once daily in treating the signs and symptoms of psoriatic arthritis.

Objective: To evaluate the efficacy of the cyclooxygenase-2 selective inhibitor celecoxib in treating patients with psoriatic arthritis (PsA) in flare.

Methods: This 12-week, multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel-group study compared the efficacy and safety of celecoxib 400 mg (n=201) or celecoxib 200 mg (n=213) once daily (qd) with placebo (n=194) in treating the signs and symptoms of PsA in flare. The primary efficacy measure was the number of patients responding to treatment according to the American College of Rheumatology Responders Index 20% (ACR-20) at week 12. Efficacy and safety were assessed for all randomized patients who received at least 1 dose of study medication.

Results: At the week-12 primary endpoint, approximately 50% of patients in each treatment group were responders according to the ACR-20 criteria, and no statistically significant treatment differences between treatment groups were observed. However, at week 2, the ACR-20 response rates for the celecoxib 400 mg (49%) and 200 mg (39%) groups were significantly higher than for the placebo group (28%) (P<0.001 and P=0.016, respectively). Within the celecoxib 400 mg group, ACR-20 response rates were similar at weeks 2, 6 (46%), and 12 (49%). In contrast, in the celecoxib 200 mg and placebo treatment groups, ACR-20 response rates increased 7 and 16%, respectively, from week 2 to week 6, and remained relatively unchanged from week 6 to week 12. There were no statistically significant differences in ACR-20 response rates between the celecoxib 400 mg and 200 mg groups at any time point. Treatment with celecoxib 200 and 400 mg qd was statistically superior to placebo treatment at weeks 2 and 6 for Patient's Assessment of Arthritis Pain. Both doses of celecoxib were well tolerated.

Conclusions: Celecoxib 400 mg and 200 mg qd were efficacious and well tolerated in treating the signs and symptoms of PsA in flare after 2 weeks of treatment. However, although the clinical effects of celecoxib 400 mg and 200 mg qd were observed for 12 weeks, there was a high placebo response at these time points, and there were no differences relative to placebo treatment at week 12.