Efficacy of nabumetone versus diclofenac, naproxen, ibuprofen, and piroxicam in osteoarthritis and rheumatoid arthritis.

The efficacy of nabumetone was compared with that of diclofenac, naproxen, ibuprofen, and piroxicam in patients with osteoarthritis (OA) or rheumatoid arthritis (RA) in a randomized, controlled, open-label, multicenter trial. Patients > or = 18 years with clinical and radiographic evidence of OA or RA (functional class I, II, or III), who provided written informed consent, were eligible. To mimic real-life therapy, no washout phase preceded randomization. Eligible patients were assigned in a 3:1 ratio to receive nabumetone or a comparator NSAID for 12 weeks. Thus a total of 4,411 eligible patients were randomized to receive nabumetone (N = 3,315) or one of the comparator NSAIDs (N = 1,096). Initial daily doses were: nabumetone, 1,000 mg; diclofenac, 100 mg; naproxen, 500 mg; ibuprofen, 1,200 mg; piroxicam, 10 mg. Dosage increases were permitted after a 2-week trial period. All patients were evaluated at baseline, and at 4 and 12 weeks. Of all patients randomized, approximately 46% had RA and approximately 54% had OA. Demographic characteristics were similar for the nabumetone and comparator NSAID treatment groups. In OA, nabumetone was as effective as the comparator NSAIDs in the physician and patient global assessments of disease activity, in improving the Activities and Lifestyle Index, and in decreasing the degree of pain. There was no significant difference in the percentage of patients withdrawn for lack of efficacy when treated with nabumetone or one of the comparator NSAIDs. In contrast, nabumetone was significantly (p < or = 0.02) more effective than the comparator NSAIDs in RA patients for the global assessments of disease activity, pain relief, and improving the Activities and Lifestyle Index, primarily due to the poor response in the ibuprofen and piroxicam treatment groups. Furthermore, fewer nabumetone-treated RA patients (8.8%) withdrew for lack of efficacy than those treated with diclofenac (10.3%), naproxen (11%), piroxicam (13.5%), or ibuprofen (13.2%). In conclusion, in a large, randomized, open-label trial that mimicked real-life therapy, nabumetone was as effective as diclofenac, naproxen, piroxicam, and ibuprofen for the treatment of patients with OA. However, in RA, nabumetone was significantly more effective than the comparator NSAIDs, and fewer patients were withdrawn because of lack of efficacy.