Adalimumab in rheumatoid arthritis treatment: a systematic review and meta-analysis of randomized clinical trials

Since the discovery of the role of tumor necrosis factor in the physiopathological process of rheumatoid arthritis, five drugs that block this cytokine have been used as therapeutic options. To evaluate the efficacy and safety of adalimumab in the treatment of rheumatoid arthritis we performed a systematic review and meta-analysis of randomized controlled trials. A search of relevant studies in Medline (through PubMed) and LILACS in June 2011 was carried out. Study selection, data collection and analysis were performed in pairs and independently by two reviewers and by a third reviewer in cases of disagreement. The meta-analysis was performed using the software Review Manager® 5.1 using the random effects model. Eleven articles related to adalimumab were included and considered nine studies with 3461 patients. Ten studies showed low risk of bias regarding the blinding of participants and personnel and blinding of outcome assessment. Patients who received the combination treatment of adalimumab and methotrexate showed better efficacy results and lower radiographic progression when compared to placebo + methotrexate in 24-104 weeks. Patients who received adalimumab as monotherapy showed better efficacy outcomes when compared to placebo in 24 and 26 weeks. The results of the meta-analyses of adverse events were not statistically significant, except for reactions at the injection site, which favored the control group. Adalimumab efficacy was demonstrated in monotherapy and when associated to a DMARD, but the evidence for combined use is more robust.