carboplatin + etoposide + gemcitabine

**Carboplatin + etoposide + gemcitabine** is a three-drug chemotherapy combination used in clinical studies for advanced cancers. Carboplatin is a platinum-based alkylating agent that crosslinks DNA to inhibit replication (mechanism: DNA crosslinking via intra- and inter-strand adducts). Etoposide is a topoisomerase II inhibitor that stabilizes the DNA-enzyme cleavage complex, preventing religation and causing DNA breaks. Gemcitabine is a nucleoside analog that incorporates into DNA, leading to masked chain termination and inhibition of ribonucleotide reductase. This regimen has been evaluated primarily in phase I/II trials for cancers such as small cell lung cancer and carcinoma of unknown primary, showing activity but with considerable hematologic toxicity including neutropenia, thrombocytopenia, and anemia. It is administered intravenously in cycles, often as part of investigational protocols.