lenvatinib + pembrolizumab + pemetrexed + cisplatin

A four-drug combination regimen consisting of lenvatinib, pembrolizumab, pemetrexed, and cisplatin, used in the investigational or clinical trial setting for various advanced solid tumors, particularly non-small cell lung cancer (NSCLC). - **Lenvatinib** is a small molecule multi-kinase inhibitor targeting vascular endothelial growth factor receptors (VEGFR1-3), fibroblast growth factor receptors (FGFR1-4), platelet-derived growth factor receptor alpha (PDGFRα), RET, and KIT, thereby inhibiting tumor angiogenesis and proliferation. - **Pembrolizumab** is a monoclonal antibody that blocks the programmed cell death 1 (PD-1) receptor, preventing cancer cells from evading immune detection. - **Pemetrexed** is an antifolate chemotherapy agent that inhibits enzymes involved in purine and pyrimidine synthesis, thus preventing cell replication. - **Cisplatin** is a platinum-based chemotherapy agent that causes DNA crosslinking, leading to apoptosis of rapidly dividing cancer cells. Used together, the regimen combines immunotherapeutic (pembrolizumab), antiangiogenic/targeted (lenvatinib), and cytotoxic (pemetrexed, cisplatin) components to maximize anti-tumor activity.