Etanercept biosimilar demonstrates long-term safety, efficacy in rheumatoid arthritis

YLB113, a biosimilar of the reference product etanercept, appears to be safe for long-term treatment of patients with rheumatoid arthritis, with efficacy sustained for up to 96 weeks, according to a study. Notably, the biosimilar is associated with fewer cases of injection-site reactions and injection-site erythema compared with the reference.

Researchers used data from a phase III, double-blind, randomized, 96-week equivalence study, looking at the 201 participants who received 50 mg YLB113 subcutaneously every 2 weeks. Key safety endpoints included adverse events (AEs), injection-site reactions, injection-site erythema, antidrug antibody (ADA) and efficacy. The efficacy endpoint was the change in Disease Activity Score 28-joint count (DAS28) over time.

A total of 184 participants (91.5 percent) completed the study. Most patients (93.5 percent) experienced treatment-emergent AEs, and 10.0 percent had severe AEs. AEs led to treatment discontinuation in 2.0 percent of the patients.

Overall, injection-site reactions occurred in 20.0 percent of participants throughout the open-label extension study. Two participants developed ADAs, but none developed neutralizing ADAs at any time after study drug administration.

From baseline, the mean change in DAS28 was 2.22 at the study transition, 2.10 at week 72, and 2.06 at the end of the study.

In the post hoc analysis, YLB113 was associated with a significantly lower frequency of injection-site reactions (3.8 percent; p<0.0001) and injection-site erythema (1.9 percent; p<0.0001) relative to the reference product etanercept.