A randomized, double-blind, phase III study assessing clinical similarity of SB17 (proposed ustekinumab biosimilar) to reference ustekinumab in subjects with moderate-to-severe plaque psoriasis

Background: Ustekinumab (UST) is a safe and effective treatment for moderate-to-severe psoriasis. Objectives: To compare efficacy, safety, pharmacokinetics (PK), and immunogenicity of the proposed UST biosimilar SB17 with reference UST in subjects with moderate-to-severe plaque psoriasis. Methods: In this randomized double-blind study, subjects were randomized to receive 45 mg of SB17 or UST subcutaneously at week 0, 4, and every 12 weeks. The primary endpoint was the percent change from baseline in Psoriasis Area and Severity Index at week 12 with an equivalence margin of [15%, 15%]. Other secondary efficacy, safety, PK, and immunogenicity endpoints were measured through week 28. Results: Two hundred forty-nine subjects were randomized to SB17, 254 to UST. Adjusted difference of Psoriasis Area and Severity Index change from baseline at week 12 of0.6% (95% confidence interval;3.780, 2.579) was within the equivalence margin. Physician’s Global Assessment and Dermatology Life Quality Index were also comparable. Overall treatment-emergent adverse events were comparable (SB17: 48.2%, UST: 48.8%). The overall incidence of antidrug antibodies up toWeek 28 was 13.3% with SB17 and 39.4% with UST. Limitations: Data were only through week 28. Conclusion: SB17 was clinically biosimilar to UST up to week 28. ( J Am Acad Dermatol 2024;91:440-7.)