The therapy of rheumatoid arthritis has been changed by biological treatments. Their efficacy was evaluated in several randomized controlled trials. These trials were different in patient characteristics and the administration regimen. Placebo was the control and direct comparison of biological treatments is missing.
In the present study the efficacy of biological treatments in patients with rheumatoid arthritis was compared based on the randomized controlled trials available in the literature. A meta-analysis was conducted and meta-regression was used to explore the relationship between disease characteristic variables and observed efficacy.
The related scientific literature is broad. Thirty two trials involving 18,500 patients were included into the current meta-analysis. The relative odds ratios of biological treatments compared to placebo varied between 3.6 and 20.0, and between 6.4 and 35.5 in case of monotherapy and combination with non-biological therapy, respectively. Disease duration and added non-biological therapy were in positive relationship with relative efficacy. More severe disease resulted smaller relative effect.
The results show that the efficacy of biological treatments is similar. The relative efficacy worsens with more severe disease and improves with disease duration.