Rofecoxib 12.5 mg, rofecoxib 25 mg, and celecoxib 200 mg in the treatment of symptomatic osteoarthritis: results of two similarly designed studies.

Objective: To compare the efficacy of rofecoxib and celecoxib for the treatment of knee or hip OA over 6 weeks.
Methods: Two similarly designed, multicenter, randomized, double-blind, placebo-controlled studies. Patients were randomly assigned 3:3:3:1 in Study 1 to once daily (QD) rofecoxib 12.5 mg (N = 456), rofecoxib 25 mg (N = 459), celecoxib 200 mg (N = 456), or placebo (N = 150) and 3:3:1 in Study 2 to QD rofecoxib 25 mg (N = 471), celecoxib 200 mg (N = 460), or placebo (N = 151). There was no rofecoxib 12.5 mg arm in Study 2. The primary outcome measure of both studies was pain at night over 6 weeks for rofecoxib 25 mg vs. celecoxib 200 mg. Efficacy comparisons with rofecoxib 12.5 mg in Study 1 were included as pre-specified study objectives but not as pre-specified study hypotheses. Secondary endpoints included Patient Global Assessment of Response to Therapy (PGART) over 6 weeks and over 1 week. Safety was evaluated through the assessment of spontaneously reported adverse experiences (AEs), evaluation of vital signs, and laboratory data reported by investigators and patients.
Results: For the primary endpoint, reduction in pain at night over 6 weeks in Study 1 was not significantly different between active treatments; in Study 2 rofecoxib 25 mg significantly (p = 0.023) reduced pain at night compared with celecoxib 200 mg over 6 weeks. For the secondary endpoints, in both studies, significantly (p < 0.05) more patients treated with rofecoxib 25 mg than celecoxib 200 mg had a good or excellent PGART over 6 weeks, and over the first week (p < 0.01). In both studies, there were no significant differences between active medications in the incidence of reported overall, serious, or drug-related AEs. The reported AE rates with the active treatments were generally similar to those with placebo in the two studies.
Conclusions: Rofecoxib 25 mg was significantly better than celecoxib 200 mg in relieving night pain at 6 weeks in one study; this was not confirmed in the accompanying study.