gemcitabine + cisplatin + PD-L1 inhibitor + capecitabine

This is a four-drug combination regimen consisting of gemcitabine, cisplatin, a PD-L1 inhibitor (such as durvalumab or atezolizumab), and capecitabine. Gemcitabine is a nucleoside analog that inhibits DNA synthesis, leading to apoptosis in rapidly dividing tumor cells. Cisplatin is a platinum-based chemotherapeutic agent that forms DNA crosslinks and induces cell death. Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) that interferes with DNA synthesis by inhibiting thymidylate synthase. The PD-L1 inhibitor component blocks the interaction between programmed death-ligand 1 (PD-L1) on tumor cells and the PD-1 receptor on T-cells, thereby enhancing anti-tumor immune responses. This combination aims to leverage both cytotoxic chemotherapy and immunotherapy for synergistic anti-cancer effects, particularly in advanced solid tumors such as pancreatic or biliary tract cancers[7]. While combinations of gemcitabine/cisplatin/capecitabine are established in clinical practice for certain cancers[4][7], the addition of a PD-L1 inhibitor represents an investigational approach currently being explored in clinical trials.