Objective: To evaluate the efficacy of rofecoxib (Vioxx) in subpopulations of patients with osteoarthritis (OA) identified by demographic or baseline disease characteristics, or varied OA involvement.
Methods: Data were combined from three 6-week double blind trials in patients with OA of the knee or hip. All trials contained placebo, 12.5 mg rofecoxib, and 25 mg rofecoxib arms (the only trials to date containing all 3 treatments). Analyses were performed on subgroups categorized according to the following baseline demographics and disease characteristics [age, sex, height, weight, body mass index, American Rheumatism Association (ARA) functional class, joint tenderness, joint stiffness, Western Ontario-McMaster University OA Index (WOMAC) functional subscale, unilateral/bilateral joint involvement, number of joint groups involved]. Three primary endpoints--Pain Walking on Flat Surface (WOMAC), Patient Global Assessment of Response to Therapy, and Investigator Global Assessment of Disease Status--were analyzed. The global assessments, which provided data on overall aspects of OA, regardless of affected joint, were used to assess effects among patients with one, 2, 3, or 4 joint groups affected (from among the following: interphalangeal/first carpal-metacarpal joint, spine, hip, or knee).
Results: Data from 1501 patients were included. No consistent treatment-by-subgroup interaction was observed with all 3 primary endpoints for patients taking placebo or 12.5 or 25 mg rofecoxib. Rofecoxib showed generally consistent efficacy across subgroups of patients identified by sex, race, age, OA location(s), prior OA therapy, baseline study joint tenderness or swelling (patients with knee OA only), and ARA functional class level.
Conclusion: In this combined analysis, no specific factor predicted a differential treatment effect to rofecoxib.