Cyclosporin A in rheumatoid arthritis: overview of efficacy

Five clinical trials of cyclosporin A (CyA) in the treatment of RA were reviewed and an initial evaluation made of clinical endpoints across the studies. A composite effect score for efficacy and the rates of dropout due to toxicity were each compared to earlier meta-analyses evaluating the relative efficacy and toxicity of second-line drugs for RA. The overall percentage improvements over a 6-month assessment period for the various clinical endpoints were all found to meet a minimal clinical improvement of 20%: tender joints, 20%; grip strength, 22%; swollen joints, 29%; functional index, 29%; morning stiffness, 40%; and CRP, 45%. The exception was ESR (16%). The composite effect for CyA indicated significant improvement over placebo (P < 0.001). This effect in excess of placebo was in the range of that found for antimalarial drugs. The toxicity associated with CyA was similar to that found with drugs with low toxicity, such as auranofin. A more detailed analysis using individual patient data and the results of two studies is planned.