cadonilimab + bevacizumab + regorafenib + fruquintinib

This combination is an **experimental multi-drug regimen** composed of four agents: - **Cadonilimab**, a bispecific monoclonal antibody targeting PD-1 and CTLA-4, designed to enhance immune response against tumors through dual immune checkpoint blockade. - **Bevacizumab**, a monoclonal antibody that binds vascular endothelial growth factor A (VEGF-A), inhibiting angiogenesis and thereby starving tumors of a blood supply. - **Regorafenib**, an oral small molecule multi-kinase inhibitor that blocks several kinases involved in angiogenesis, oncogenesis, and the tumor microenvironment, including VEGFR, PDGFR, and KIT. - **Fruquintinib**, a highly selective small molecule inhibitor of VEGFR-1, 2, and 3, providing potent anti-angiogenic activity. This combination is being explored for the treatment of **metastatic colorectal cancer (mCRC)**, leveraging synergistic effects of immune checkpoint inhibition and anti-angiogenic therapy. Both regorafenib or fruquintinib have demonstrated efficacy, particularly when combined with immune checkpoint inhibitors, showing moderate clinical benefit and manageable safety profiles[1][7][5].