Biosimilar SB17 versus reference ustekinumab in moderate to severe plaque psoriasis after switching: phase 3 study results up to week 52

Abstract

Introduction SB17 is a biosimilar to reference ustekinumab (UST). We compared the efficacy, safety, and immunogenicity of SB17 to UST up to Week 52, including switching from UST to SB17. Methods Subjects were randomized to receive 45 mg of SB17 or UST subcutaneously up to Week 40. At Week 28, subjects from the UST treatment group were re-randomized to either switch to SB17 or continue UST. Efficacy, safety, and immunogenicity were assessed up to Week 52. Results Among baseline randomized 503 subjects, 481 subjects were re-randomized at Week 28; continuing SB17 (SB17 + SB17, n = 237), switching from UST to SB17 (UST+SB17, n = 122) or continuing UST (UST+UST, n = 122). The percent change from baseline in Psoriasis Area and Severity Index (PASI) was comparable between treatment groups up to Week 52 (SB17 + SB17: 95.8%, UST+SB17: 95.6%, UST+UST: 94.5% at Week 52). Other efficacy endpoints were also comparable. The incidence of treatment-emergent adverse events (SB17 + SB17: 16.5%, UST+SB17: 13.9%, UST+UST: 23.8%) and the overall incidence of anti-drug antibodies occurring after transition were comparable between treatment groups (SB17 + SB17: 5.6%, UST+SB17: 5.1%, and UST+UST: 6.7%). Conclusion SB17 demonstrated clinical biosimilarity to UST after switching from UST, and maintained long-term comparable efficacy and safety with UST up to Week 52.