OBJECTIVES: To compare the efficacy results of biological therapies for rheumatoid arthritis (RA) using indirect treatment comparisons and meta-regression techniques. METHODS: We performed a literature search to identify the randomized clinical trials (RCTs) of biological therapies for RA. Using these studies we created a network and developed two random effects, logistic regression models (6- and 12-months), using the ACR-50 as the primary outcome. We chose mean disease duration and mean baseline HAQ-DI score as meta-regression covariates, to account for heterogeneity between trials, as these have prognostic value in determining the effect of RA treatment. RESULTS: We included 18 RCTs in the 6-month analysis and 10 RCTs in the 12-month analysis. Eight biologic agents are included in the 6-month analysis and six in the 12-month. The results of the 6-month analysis suggest that the eight biologic agents are significantly more effective than the comparator (p <0.05): Certulizumab (log odds ratio, median=2.6), rituximab (1.7), adalimumab (1.6), infliximab (1.6), etanercept (1.4), golimumab (1.3), abatacept (1.2), and anakinra (1.0). The results also indicate that methotrexate (MTX) is significantly more effective than placebo (0.7). The parameter values for the 12-month analysis are similar, with the effectiveness of the biologics following the same order, but without golimumab and anakinra. CONCLUSIONS: Our results suggest that biologic treatments are more effective than MTX or placebo, but they may differ from one another. There are differences in the outcomes depending on whether we evaluate the ACR-50 at 6-months or 12-months. Biologic agents seem to be more effective with longer disease duration.