Biologics are an important therapeutic option for treating patients with rheumatoid arthritis (RA). However, they are associated with rare but severe adverse events such as serious infections, lymphoma, or chronic heart failure. In addition, dosing regimens and routes of administration differ substantially among biologics. In a systematic review, we assessed the comparative efficacy and safety of biologic agents for RA.
We searched electronic databases up to May 2006. We limited evidence to controlled trials for efficacy but included observational evidence for safety. Outcomes of interest were clinical response, radiographic progression, and quality of life. Given the paucity of head-to-head evidence, we conducted adjusted, indirect comparisons of placebo-controlled trials.
Twenty-six controlled trials provided efficacy data; 18 additional studies assessed safety. The only evidence directly comparing 2 biologic agents was a nonrandomized, open-label trial that found no differences in effectiveness and safety between etanercept and infliximab. Adjusted indirect comparisons indicate no significant differences in efficacy between anti-tumor necrosis factor (TNF) drugs. However, anti-TNF drugs appear to be more efficacious than anakinra, although not all comparisons reached statistical significance. Because of the lack of sound longterm safety data, evidence is insufficient to draw firm conclusions about the comparative safety of biologics.
Anti-TNF drugs appear to be more efficacious than anakinra but do not differ significantly among each other. Clinical considerations such as comorbidities, route of administration, dosing regimens, and specific side effect profiles may guide the choice of an anti-TNF drug.