The clinical evidence was derived from two multicentre blinded randomised controlled trials (RCTs) comparing CZP + MTX to placebo + MTX (the RAPID 1 and RAPID 2 trials). RAPID 1 lasted 52 weeks with 982 patients and RAPID 2 24 weeks with 619 patients. Evidence for clinical effectiveness of CZP in mono-therapy came from the 24-week FAST4WARD trial with 220 patients that compared CZP (400 mg every 4 weeks) versus placebo. The three key RCTs demonstrated statistically significant superiority of CZP + MTX versus placebo + MTX and of CZP versus placebo with respect to a variety of outcomes including ACR 20, ACR 50 and ACR 70 measures and quality of life measures at 3 and 6 months. On the basis of results from the indirect comparison meta-analyses, the manufacturer suggested that CZP may be at least as effective as other 'biological' DMARD (bDMARD) comparators and, in a few ACR measures at 3 and 6 months, more effective. CZP is an effective therapy for adult RA patients whose disease has failed to respond adequately to cDMARDs including MTX or who are intolerant of MTX. The cost-effectiveness of CZP relative to other bDMARDs is unclear because the economic modelling undertaken may have ignored relevant effectiveness data and potential differences between trial populations, and so may have included effectiveness results that were biased in favour of CZP