Objective: To evaluate the prevention of joint destruction and clinical efficacy of low-dose etanercept (ETN) (25 mg/week) compared with standard-dose ETN (50 mg/week) in RA.
Methods: In this prospective, randomized, open-label study, 70 patients were assigned to receive ETN at either 50 or 25 mg/week for 52 weeks. The primary endpoint was the variation in modified total Sharp score (mTSS), and secondary endpoints were variations in disease activity score in 28 joints (DAS-28), modified HAQ and adverse event rate. Values of mTSS were calculated at baseline and after 52 weeks. Non-progression was estimated as ΔmTSS ≤0.5, and the non-progression rate was compared between groups.
Results: Mean values at baseline were as follows: disease duration 9.2 years; DAS-28 5.45; and annual progression of mTSS 26.1. No significant differences in background were seen between groups. At 52 weeks, the non-progression rate was significantly less in the 25 mg/week group (36.7%) than in the 50 mg/week group (67.7%) (P = 0.041). Mean ΔmTSS was higher at 25 mg/week (1.03) than at 50 mg/week (-0.13). DAS-28 was significantly improved at 4 weeks, and the effect of treatment lasted for 52 weeks in both groups. No differences in adverse event rates were seen between groups.
Conclusion: Low-dose ETN is not inferior to standard-dose ETN in terms of effects on clinical manifestations. However, in terms of the radiographic non-progression rate, the effects of low-dose ETN may be inferior to the effects of standard-dose ETN.
Trial registration: UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/, UMIN000001798.