regorafenib + pembrolizumab

Regorafenib + pembrolizumab is a combination therapy under investigation for the treatment of various advanced cancers, including metastatic or unresectable microsatellite instability-high (MSI-H) and microsatellite stable (MSS) colorectal cancer, as well as advanced hepatocellular carcinoma (HCC)[1][3][4][5]. Regorafenib is an oral small molecule multi-kinase inhibitor that targets several membrane-bound and intracellular kinases involved in tumor angiogenesis, oncogenesis, metastasis, and tumor immunity. Its targets include vascular endothelial growth factor receptor 1 (VEGFR1), fibroblast growth factor receptor 1 (FGFR1), platelet-derived growth factor receptor alpha (PDGFRα), angiopoietin receptor TIE2, KIT, RET, RAF1, BRAF and others[6]. Pembrolizumab is a monoclonal antibody that inhibits the programmed cell death protein 1 (PD-1) receptor on T cells to enhance anti-tumor immune responses. The rationale for combining these agents is based on preclinical evidence suggesting synergistic antitumor activity through modulation of the tumor microenvironment by regorafenib—such as reducing immunosuppressive macrophages and normalizing vasculature—thereby enhancing the efficacy of immune checkpoint blockade with pembrolizumab[2][5].