BACKGROUNDBAT2206 is a proposed biosimilar to reference ustekinumab (UST; Stelara).OBJECTIVESTo compare the efficacy and safety of BAT2206 with UST at 2 treatment periods, ie, a 28-week initial treatment period 1 (TP1) and a 24-week secondary TP2. This article describes the results of TP1.METHODSIn this randomized, double-blind, phase III study, adult patients with moderate to severe plaque psoriasis were randomized (1:1) to receive 45 or 90 mg of BAT2206 or UST until week 28 in TP1, depending on their baseline body weight. The primary end point was the percent change from baseline in Psoriasis Area and Severity Index score to week 8 or 12. The secondary end points included safety, pharmacokinetics, and immunogenicity parameters.RESULTSIn all, 278 patients were each randomized into the BAT2206 or UST groups. At weeks 8 and 12, the least squares mean difference (standard error) for percent change from baseline in Psoriasis Area and Severity Index score was 0.964 (1.8952) and 1.774 (1.4912), respectively, and the least squares mean difference confidence intervals all completely fell within the predefined equivalence margins. Comparable results were observed between the treatment groups for secondary end points.LIMITATIONSOwing to the length limit, this article only described the findings from TP1.CONCLUSIONSBAT2206 and UST were comparable in terms of efficacy, safety, pharmacokinetics, and immunogenicity.