Safety and Efficacy of Prefilled Liquid Etanercept-Biosimilar Yisaipu for Active Ankylosing Spondylitis: A Multi-Center Phase III Trial

INTRODUCTION: The aim of this work is to examine the efficacy and safety of prefilled liquid etanercept-biosimilar Yisaipu versus lyophilized Yisaipu in active ankylosing spondylitis (AS) patients. METHODS: This double-blind, phase III trial with non-inferiority design randomized adult patients with active AS in a 3:1:1 ratio to receive twice-weekly 25-mg prefilled liquid Yisaipu for a total of 48 injections (group I, n = 330), once-weekly 50-mg prefilled liquid Yisaipu for 24 injections (group II, n = 110), or twice-weekly 25-mg lyophilized Yisaipu for 48 injections (group III, n = 110). Both physicians and patients who received 25-mg twice-weekly lyophilized or liquid Yisaipu were blinded to treatment assignment while patients who received 50-mg once-weekly liquid Yisaipu received treatment in an open-label design. In addition, 90 patients in the PK/PD study were randomized in a 1:1:1 ratio to each group. The primary outcome was the proportion of patients who achieved ASAS20 at week 24. RESULTS: A total of 640 subjects were enrolled. The proportion of patients who attained ASAS20 at week 24 was 85.56% in group I, 85.71% in group II, and 83.45% in group III (group I vs. III, P = 0.545; group II vs. III, P = 0.605). The difference between group I and III was 2.10% (95% CI − 5.06%, 9.27%) and 2.26% (95% CI − 6.21%, 10.73%) between group II and III, meeting the non-inferiority threshold (Δ = − 15%) (P < 0.001). Except for a statistical difference between group I (75.83%) and group III at week 8 (64.75%, P = 0.011), there was no statistical difference in the ASAS20 attainment rate among the three groups at other time points. The incidence of serious adverse events was comparable among the three groups (group I, 2.50%, II, 2.86% and III, 1.43%; P > 0.05). No deaths were reported. CONCLUSIONS: Once-weekly 50-mg or twice-weekly 25-mg prefilled liquid Yisaipu is safe and non-inferior to twice-weekly 25-mg lyophilized Yisaipu. TRIAL REGISTRATION: CTR20130124 and NCT04345458. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40744-021-00276-1.