Comparative efficacy and safety of biosimilar Bmab 1200 versus reference ustekinumab in moderate-to-severe plaque psoriasis: 52-week findings from the Phase 3 STELLAR-2 trial

Abstract

Background: The STELLAR-2 study compared the efficacy, safety, immunogenicity, and pharmacokinetics of Bmab 1200 with reference ustekinumab through Week 52 in patients with moderate-to-severe chronic plaque psoriasis.

Research design and methods: In this double-blind, Phase 3 study, patients were randomized 1:1 to receive Bmab 1200 or reference ustekinumab (45 mg or 90 mg). At Week 16, patients responding to ustekinumab (improvement in Psoriasis Area and Severity Index [PASI] score ≥50%) were re-randomized to continue with reference ustekinumab or switch to Bmab 1200 and followed through Week 52.

Results: Overall, 324 patients completed the study. At Week 52, the mean (SD) percentage reduction in PASI scores from baseline was -95.5% (7.51) for Bmab 1200, -96.6% (5.67) for continued-reference ustekinumab, and -94.7% (7.95) for switched-to-Bmab 1200 groups. Efficacy and safety outcomes were comparable across groups. From 28 to 52 weeks, 37.8% of patients had at least one treatment-emergent adverse event. The incidence of post-switch antidrug antibodies was also comparable (Bmab 1200: 63.7%; continued-reference ustekinumab: 80.2%; switched-to-Bmab 1200: 72.6%).

Conclusions: Bmab 1200 demonstrated clinical biosimilarity to reference ustekinumab through Week 52 even after switching. Long-term comparable efficacy and safety were also maintained.

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

Keywords: Biosimilar; Bmab 1200; Phase 3; equivalence; immunogenicity; psoriasis; ustekinumab.