Efficacy and safety of the ustekinumab biosimilar, Bmab 1200, versus reference ustekinumab in moderate-to-severe plaque psoriasis: 28‑week results of the randomized, double-blind, Phase 3 STELLAR-2 study

Abstract

Background: STELLAR-2 assessed the equivalent efficacy of the ustekinumab biosimilar, Bmab 1200, versus reference ustekinumab in patients with moderate-to-severe chronic plaque psoriasis. Safety, immunogenicity, and pharmacokinetics (PK) were also evaluated.

Research design and methods: In this double-blind, parallel-group, Phase 3 study, patients were randomized 1:1 to Bmab 1200 or reference ustekinumab in Treatment Period (TP)1, and at Week 16, those who responded to reference ustekinumab (improvement in Psoriasis Area and Severity Index [PASI] score ≥ 50%) were re-randomized (1:1) to continue reference ustekinumab or switch to Bmab 1200 in TP2. The primary endpoint was the change in PASI from baseline to Week 12. Equivalent efficacy was established if 90% and 95% confidence intervals (CIs) for the treatment difference were within predefined equivalence margins of ± 10% and ± 13%, respectively.

Results: Overall, 384 patients were randomized (Bmab 1200: N = 191; reference ustekinumab: N = 193) in TP1. At Week 12, the least squares mean treatment difference (0.6800%; 90% CI: -1.27, 2.63; 95% CI: -1.64, 3.00) was within the predefined equivalence margins for 90% and 95% CIs. Safety, immunogenicity, and PK were comparable between treatment groups.

Conclusions: Bmab 1200 and reference ustekinumab had similar efficacy, safety, immunogenicity, and PK in patients with moderate-to-severe plaque psoriasis.

Trial registration: www.clinicaltrialsregister.eu identifier is 2021-006668-25; www.clinicaltrials.gov identifier is NCT05335356.

Keywords: Biosimilar; Bmab 1200; clinical equivalence; plaque psoriasis; ustekinumab.