A phase 3 randomized, double-blind, multicenter comparative study evaluating the effect of etanercept versus methotrexate on radiographic outcomes, disease activity, and safety in Japanese subjects with active rheumatoid arthritis

Objectives The aim of this phase 3, double-blind study was to compare the radiographic and clinical effects of etanercept (ETN) versus methotrexate (MTX) over 52 weeks in Japanese subjects with active rheumatoid arthritis. Methods The study population comprised 550 subjects with inadequate response to ≥1 disease-modifying anti-rheumatic drugs who were randomized to treatment groups of ETN 25 mg twice weekly (BIW; n = 182), ETN 10 mg BIW (n = 192), or MTX (≤8.0 mg/week; n = 176). Results Of the 550 subjects initially enrolled in the three treatment groups, 21.6 % discontinued the study; a significantly higher proportion of those who withdrew from the study due to lack of efficacy were in the MTX (21.6 %) group compared with the ETN 25 mg (3.3 %) and ETN 10 mg (6.8 %) groups (P < 0.001). Mean change from baseline in the modified total Sharp score at week 52 (primary endpoint) was significantly lower in the ETN 25 mg [3.33; standard error (SE), 0.73] and ETN 10 mg (5.19; SE 0.93) groups than in the MTX group (9.82; SE 1.16; P < 0.0001 vs. either ETN group). Compared with subjects receiving MTX, significantly higher percentages of subjects treated with ETN 25 and 10 mg achieved American College of Rheumatology (ACR) ACR20 and ACR50 response rates at all time points (P < 0.01). ETN was well-tolerated, with no unexpected safety findings. Conclusions ETN 25 mg BIW and ETN 10 mg BIW slowed radiographic progression and improved clinical outcomes more effectively than MTX in this Japanese population.