sacituzumab tirumotecan + pembrolizumab + fluoropyrimidine

**sacituzumab tirumotecan + pembrolizumab + fluoropyrimidine** is an investigational combination therapy comprising: - **sacituzumab tirumotecan** (sac-TMT), a TROP2-directed antibody-drug conjugate composed of an anti-TROP2 monoclonal antibody linked via a novel linker to a belotecan-derived topoisomerase I inhibitor (KL610023). The ADC disrupts tumor cell division and induces DNA damage. - **pembrolizumab**, a humanized anti–PD-1 monoclonal antibody (immune checkpoint inhibitor) blocking the PD-1/PD-L1 pathway to enhance immune-mediated killing of tumor cells. - **fluoropyrimidine**, referring to antimetabolite drugs such as 5-fluorouracil and prodrugs like capecitabine, which are converted to 5-fluorouracil in vivo and act mainly by inhibiting thymidylate synthase, disrupting DNA synthesis and function. The combination targets multiple mechanisms: tumor cell division, immune checkpoint inhibition, and nucleotide synthesis interference. Currently, this combination is under investigation in clinical trials for advanced/metastatic breast and solid tumors in patients refractory to standard treatment[1][3][5][7].