erlotinib + gefitinib + icotinib + osimertinib

This is a combination of four EGFR tyrosine kinase inhibitors (EGFR-TKIs) including three first-generation inhibitors (erlotinib, gefitinib, icotinib) and one third-generation inhibitor (osimertinib). While not typically administered together as a four-drug regimen, various combinations of these agents are being explored to overcome resistance mechanisms in EGFR-mutant non-small cell lung cancer (NSCLC). The theoretical basis for combining these agents is that they have different binding profiles and efficacy against various EGFR mutations, potentially allowing for more comprehensive inhibition of EGFR signaling and prevention of resistance development.