Rofecoxib for rheumatoid arthritis.

BACKGROUND

Editor's note: The anti-inflammatory drug rofecoxib (Vioxx) was withdrawn from the market at the end of September 2004 after it was shown that long-term use (greater than 18 months) could increase the risk of heart attack and stroke. Further information is available at www.vioxx.com. Rheumatoid arthritis (RA) is a systemic auto-immune disorder, in which the synovial lining of many joints and tendon sheaths are persistently inflamed.

OBJECTIVES

To assess the efficacy and toxicity of rofecoxib for treating RA.

SEARCH STRATEGY

We searched the following electronic databases up to December 2000: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, National Research Register, NHS Economic Evaluation Database, Health Technology Assessment database. The bibliographies of retrieved papers were scanned for additional references. The manufacturers of rofecoxib, MSD, were also approached by the UK National Institute for Clinical Excellence to submit additional evidence to inform it's appraisal on the use of cyclo-oxygenase inhibitors for arthritis.

SELECTION CRITERIA

We included randomised controlled trials of parallel group design evaluating the efficacy and/or toxicity of rofecoxib in RA, both placebo based and comparative trials were eligible. Relevant outcome criteria had to be available to evaluate efficacy and/or toxicity, such as the OMERACT outcomes.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by two reviewers and the results were compared for the degree of agreement. A validated tool (Jadad 1996) was used to score the quality of the randomised controlled trials. The planned analysis was to pool, where appropriate, continuous outcome measures using mean or standardized mean differences, and dichotomous outcome measures using relative risk ratios.

MAIN RESULTS

Two randomised controlled trials evaluating rofecoxib for the treatment of RA were identified and met the inclusion criteria. One compared rofecoxib to placebo and was designed to assess the safety and efficacy of several doses of rofecoxib. The second trial compared rofecoxib to naproxen and was primarily designed to assess the safety of rofecoxib so did not include all the recommended RA efficacy measures. The overall number of ACR 20 responders who had received 25mg (82/ 171 = 48%) or 50mg (86/161 = 53%) was statistically significantly more than those receiving placebo (58/168 = 35% ) (RR 1.39 CI: 1.07, 1.80 and RR 1.55 CI: 1.20, 1.99 respectively) with no statistically significant differences between the 25 and 50 mg doses. The safety profile of rofecoxib was similar to that of placebo. In the comparative trial, rofecoxib at a dosage of 50 mg/day demonstrated similar efficacy to naproxen at a dosage of 500 mg twice daily. However, the combined rate of clinically significant complicated gastro-intestinal events (GI) (perforations, ulcers, bleeds, or obstructions) was lower with rofecoxib than with naproxen (RR 0.46, 95% CI, 0.34 to 0.63) due to a reduction in the number of ulcers and bleeds. Compared to patients taking naproxen, patients taking rofecoxib had a greater risk of having any cardiovascular event (45/4047 = 1.1% vs 19/4029 =0.47%) (RR 2.36 CI 1.38 to 4.02) and had greater risk of having a non-fatal myocardial infarction (MI) (18/4047 =0 .44% and 4/4029 =0.1%) (RR 4.48, 95% CI, 1.52 to 13.23).

AUTHORS' CONCLUSIONS: In patients with RA, rofecoxib demonstrates a greater degree of efficacy than placebo, while having a comparable safety profile. Rofecoxib demonstrates a similar degree of efficacy as naproxen, but with a significantly lower rate of ulceration and gastrointestinal bleeding. Rofecoxib was associated with a greater risk for MI, but the exact significance and pathophysiology of this possible relationship is unclear. Rofecoxib was voluntarily withdrawn from global markets in October 2004. It cannot therefore be prescribed and therefore there are no implications for practice concerning its use. None the less when considering which NSAID to use, it must be borne in mind that the toxicity of NSAIDs is variable amongst patients and drugs and it tends to be dose related and associated with variation in the mode of action, absorption, distribution and metabolism. There remains a number of questions over both the benefits and risks associated with Cox II selective agents and further work is ongoing. It is likely that this issue will not be resolved until research has enabled a fuller understanding of the complex mechanism by which the Cox system operates.