bevacizumab + gemcitabine + 5-fluorouracil + folinic acid

This is a **combination regimen** composed of four drugs: **bevacizumab** (a monoclonal antibody targeting vascular endothelial growth factor A/VEGF-A), **gemcitabine** (a nucleoside analog and antimetabolite), **5-fluorouracil** (5-FU, a pyrimidine analog and antimetabolite), and **folinic acid** (also known as leucovorin, a reduced folate that enhances 5-FU activity). - **Bevacizumab** works by inhibiting angiogenesis (formation of new blood vessels) in tumors by binding to VEGF-A. - **Gemcitabine** and **5-fluorouracil** act as antimetabolites, disrupting DNA synthesis and repair, leading to cancer cell death. - **Folinic acid** does not have direct anticancer activity, but it stabilizes the bond of 5-FU to thymidylate synthase, thereby enhancing the cytotoxic effects of 5-FU. This combination is an investigational regimen with primary research focus in **advanced colorectal cancer** and is not an established, globally approved standard. Its primary mechanisms are cytotoxicity and anti-angiogenesis. The combination is typically studied in patients with metastatic or advanced malignancies.