gemcitabine + paclitaxel + pemetrexed + vinorelbine

This is a four-drug combination chemotherapy regimen consisting of gemcitabine, paclitaxel, pemetrexed, and vinorelbine. Each component is a small molecule cytotoxic agent with distinct mechanisms of action targeting rapidly dividing cancer cells. - **Gemcitabine** is a nucleoside analog that inhibits DNA synthesis by incorporating into DNA and inhibiting ribonucleotide reductase. - **Paclitaxel** stabilizes microtubules and prevents their depolymerization, thereby inhibiting cell division during mitosis. - **Pemetrexed** is an antifolate that inhibits several folate-dependent enzymes involved in the synthesis of purines and pyrimidines required for DNA replication. - **Vinorelbine** is a vinca alkaloid that disrupts microtubule assembly, leading to mitotic arrest and apoptosis. These agents are individually approved or widely used for various solid tumors including non-small cell lung cancer (NSCLC), breast cancer, mesothelioma, and others[5][6][8][10]. While combinations such as gemcitabine plus paclitaxel or gemcitabine plus vinorelbine have been studied in clinical trials for metastatic breast cancer or NSCLC[1][2][4][5], there are no standard regimens or published studies specifically evaluating the efficacy or safety of all four drugs together as a single regimen.