surufatinib + fulvestrant + chidamide

This is a combination therapy consisting of three distinct drugs: 1. **Surufatinib**: An oral angio-immuno kinase inhibitor that selectively inhibits tyrosine kinase activity associated with vascular endothelial growth factor receptors (VEGFR-1/2/3), fibroblast growth factor receptor (FGFR-1), and colony stimulating factor-1 receptor (CSF-1R). This dual mechanism of action inhibits tumor angiogenesis and regulates tumor-immune evasion, potentially enhancing antitumor efficacy. 2. **Fulvestrant**: An estrogen receptor antagonist. 3. **Chidamide**: A histone deacetylase (HDAC) inhibitor. The combination may offer synergistic effects in treating advanced solid tumors, particularly neuroendocrine tumors.