SAR443726

SAR443726 is an investigational bispecific nanobody (VHH) developed by Sanofi that simultaneously targets interleukin-13 (IL-13) and OX40 ligand (OX40L). It was designed to treat type 2 inflammatory diseases, primarily atopic dermatitis, by inhibiting two distinct pathways: IL-13, a central mediator of Th2-driven inflammation, and OX40L, a co-stimulatory molecule that promotes T-cell activation and survival. The drug was evaluated in a Phase 1 first-in-human study to assess safety, tolerability, and pharmacokinetics in healthy volunteers and patients with moderate-to-severe atopic dermatitis. In 2023, Sanofi discontinued the development of SAR443726 based on its clinical profile and broader portfolio prioritization.