We present a dose-response meta-analysis to quantify relative efficacy of biologic disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA). There is a strong rationale for this analysis because, although multiple biologics are available, information on head-to-head comparisons is limited. Data on the percentage of patients attaining American College of Rheumatology (ACR) 20, 50, and 70 responses were extracted from 50 randomized controlled trials representing 21,500 patients, five mechanisms of action, and nine biologics. The analysis showed that all tumor necrosis factor inhibitors (anti-TNFs) share the same dose-response relationship for ACR 20, 50, and 70, differing only in potency. Yet there are significant differences in efficacy among the anti-TNFs due to differences in the clinical dose ranges available. At the suggested starting dose, golimumab was the least efficacious, followed by infliximab, adalimumab, etanercept, and certolizumab. Significant differences in the dose-response relationship were found between anti-TNFs and other biologics, resulting in differences in efficacy and differential impact of dose titration.