tosposertib

**Tosposertib** (previously TU2218 or NCE 401) is an orally bioavailable small molecule developed by TiumBio as a first-in-class dual inhibitor of transforming growth factor beta receptor type 1 (TGFBR1, also known as ALK5) and vascular endothelial growth factor receptor 2 (VEGFR2). It blocks TGF-β and VEGF signaling pathways, which suppress immune responses and promote tumor angiogenesis and fibrosis, enhancing the efficacy of immune checkpoint inhibitors like pembrolizumab in preclinical and clinical studies. Tosposertib has shown promising antitumor activity, including a 70.6% overall response rate in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) in a Phase 2a trial, with good tolerability and no major bleeding or cardiovascular events.[1][2][3][5]