adebrelimab + cisplatin + gemcitabine

**adebrelimab + cisplatin + gemcitabine** is an investigational combination regimen comprising three drugs: - **Adebrelimab**: a fully humanized IgG4 monoclonal antibody that selectively binds and inhibits programmed cell death-ligand 1 (**PD-L1**) on tumor and immune cells, blocking PD-L1 interaction with PD-1 and B7.1. This immune checkpoint inhibition reactivates T-cell–mediated anti-tumor activity, enhancing immune responses against cancer cells. Adebrelimab is differentiated by engineered Fc modifications that reduce Fc receptor binding, thereby minimizing unwanted immune effector functions and immune-related adverse reactions. - **Cisplatin**: a platinum-containing small molecule chemotherapy agent that forms DNA adducts (intrastrand and interstrand crosslinks), which block DNA replication and transcription, leading to apoptosis of rapidly dividing cells. - **Gemcitabine**: a nucleoside analog antimetabolite; after incorporation into DNA, it inhibits DNA synthesis and repair, acting as a masked chain terminator and depleting nucleotide pools. It also facilitates formation and effectiveness of cisplatin-DNA adducts, resulting in synergistic cytotoxicity when combined with cisplatin. This combination is explored as a treatment for various cancers, including lung and biliary tract cancers, primarily in clinical trial settings.