The board of directors of SinoMab BioScience Limited announced that, on 25 November 2023, the first cohort of healthy subjects has been successfully dosed in a phase I clinical trial of SM17 in China. As of the date of this announcement, no adverse event was observed. The phase I trial aims to establish safety, pharmacokinetics (PK) and immunogenicity profiles of SM17 in Chinese population, as well as to test the preliminary safety, efficacy and pharmacodynamic characteristic of SM17 in Atopic Dermatitis (AD) patients.

SM17 is a novel, First-in-Class (FIC), humanized, IgG4-k monoclonal antibody which is capable of modulating Type II allergic reaction by targeting the receptor of a critical ''alarmin'' molecule interleukin 25 (IL-25). SM17 could suppress Type 2 helper T (Th2) immune responses by binding to IL-25 receptor (also known as IL-17RB) on Type 2 Innate Lymphoid cells (ILC2s) and Th2 cells, to block a cascade of responses induced by IL-25 and suppress the release of the downstream Th2 cytokines such as IL-4, IL-5 and IL-13. IL-25 is a critical cytokine classified as 'alarmin'', which has shown to be implicated in the pathogenesis of autoimmune and inflammatory skin diseases, such as AD.

Patients with AD also have an increasing all-cause mortality rate and disease-specific mortality rate in the following diseases, which include infections, respiratory diseases, gastrointestinal diseases and oncologic diseases. Current approved therapies for AD, including biologics, can significantly improve eczema area and severity index and patient's quality of life. However, there is still an unmet medical need for patients showing irresponsiveness to those approved therapies.

A Phase I study for SM17 conducted in the US is near completion, with Last Subject Last Visit (LPLV) completed in September 2023, and the clinical study report is expected to be released by the first quarter of 2024.