SinoMab doses first subjects in China SM17 bridging study

SinoMab BioScience Limited announced on October 14, 2025, that the first cohort of healthy subjects has been successfully dosed with the subcutaneous formulation of SM17 in a bridging study in China. The study aims to evaluate the safety, tolerability, pharmacokinetics (PK) profiles, and bioavailability of subcutaneously administered SM17. As of the announcement date, all subjects have tolerated the treatment well, with no reported adverse events, including injection site reactions.

The bridging study is designed to enroll a total of 30 healthy subjects, with recruitment expected to be completed by November 2025 and follow-up visits by March 2026. SM17 is a novel, First-in-Class (FIC), humanized, IgG4-κ monoclonal antibody targeting the IL-25 receptor, aiming to modulate Type II allergic reactions and suppress Th2 immune responses.

The company highlights SM17's potential as a differentiating, safer, and more effective product for treating atopic dermatitis (AD). Previous studies include a first-in-human Phase 1 clinical trial in the US, which revealed a good safety profile in Q1 2024, and a Phase 1a bridging study in China completed in May 2024, showing comparable PK and good tolerability. Positive topline results from a Phase 1b proof-of-concept study, published in April 2025, indicated significant efficacy in pruritus relief, skin healing, and clear or almost clear signs of AD for the high-dose group.