fruquintinib + sintilimab + chidamide

This drug refers to the experimental combination of three agents: **fruquintinib**, **sintilimab**, and **chidamide**. **Fruquintinib** is a highly selective small molecule inhibitor targeting vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3, inhibiting angiogenesis in tumors. **Sintilimab** is a human anti–PD-1 monoclonal antibody that binds to the programmed cell death protein 1 (PD-1) receptor, blocking its interaction with PD-L1 and PD-L2, and thereby promoting T-cell mediated anti-tumor immunity. **Chidamide** is an oral, subtype-selective histone deacetylase (HDAC) inhibitor, acting predominantly on class I HDAC subtypes 1, 2, 3, and class IIb subtype 10, resulting in epigenetic modulation, increased acetylation of histones, altered gene expression, and induction of cell cycle arrest and apoptosis in tumor cells.