The objective of the study was to evaluate the efficacy and safety of etanercept (Anbainuo) treatment in Chinese moderate to severe rheumatoid arthritis (RA) with inadequate response to methotrexate (MTX-IR); 600 patients (360 in phase III-1 and 240 in phase III-2) poorly responding to MTX were enrolled in the study and randomized at a ratio of 2:1 into an Anbainuo treatment or control group. The study was designed as a 12-week double-blind, placebo-controlled period followed by a 12-week open-label study. The primary endpoint was the ACR20 response rate at week 12. Secondary endpoints included the ACR50, ACR70, ACR-N, and safety. At week 12, ACR20 response was observed in 60.9 % of the Anbainuo group-significantly higher than that of the control group (20.6 %). At week 24, the ACR20 response in the Anbainuo group increased to 70.2 %; there was no significant difference compared with that of the control group (61.8 %, P > 0.05). At week 12, the ACR50 and ACR70 responses of the Anbainuo group increased to 25.6 and 6.8 %, compared to 4 and 1 % in the control group (P < 0.001, P = 0.002). The ACR-N was 2.85 +/- 6.73 vs. -3.24 +/- 8.78 % in the control group (P < 0.001). During the first 12 weeks of treatment, 66 adverse events (AE) were reported in the Anbainuo group (15.6 %) and 21 AEs (10.5 %) occurred in the control group, whereby the rate of the Anbainuo group was slightly higher than the control group (P = 0.042). Severe adverse events (SAEs) occurred in the Anbainuo group (1.3 %) and one (SAE) occurred in the control group (0.5 %) (P = 0.19). Anbainuo displays a rapid onset of efficacy as well as good tolerance and safety in MTX-IR patients having moderate to severe RA.