Biological Response Modifiers in Rheumatoid Arthritis: Systematic Review and Meta-analysis of Safety

OBJECTIVE: To analyze available evidence on the safety of different biological response modifiers which are used for a treatment of rheumatoid arthritis (RA). MATERIALS AND METHODS: We searched systematically for randomized controlled clinical trials on treatment of RA with different biological response modifiers, followed by a systematic review with meta-analysis. Trials were searched from MEDLINE and Cochrane Library databases. The following safety parameters reported in the selected trials were analyzed: number of patients suffering any adverse event (AE), withdrawal due to AEs, serious AE (SAEs), infections, serious infections, infusion reactions, injection site reactions, malignancies, and overall mortality. Undesired effects were estimated using combined relative risks (RR) and number needed to harm (NNH). Heterogeneity was evaluated by Cochrane's Q and I(2) statistics. RESULTS: According to inclusion criteria, a total of 43 trials (20,504 patients) were included in this study. A total number of AEs were found more with abatacept (RR: 1.05, NNH: 21.93). Withdrawal due to AEs was found with all biologicals, highest with anakinra (RR: 3.48, NNH: 15.70). Patients receiving newer tumor necrosis factor-alpha inhibitors, golimumab, were more likely to develop SAEs (RR: 2.44, NNH: 12.72) and infection (RR: 1.25, NNH: 10.09), and in certolizumab, serious infections (RR: 2.95, NNH: 37.31) were found more. Infusion reaction develops more with rituximab (RR: 1.52, NNH: 8.47). Etanercept showed the highest risk to develop infusion site reaction (RR: 5.33, NNH: 4.65). Biologicals showed no difference to their control counterparts in malignancy and mortality risk. CONCLUSION: This meta-analysis helps to clarify some frequently encountered and unanswered safety questions of different biological response modifiers, a new class of drugs, in the clinical care of RA patients.