With favorable DMPK profiles, once-daily oral dosing of TRX-221 induced strong anti-tumor effects in a dose-dependent manner in a variety of osimertinib-resistant CDX and PDX models. As a reversible, selective, and broad-spectrum 4th-generation EGFR-TKI, TRX-221 is currently undergoing IND-enabling studies and shows strong potential as a therapeutic solution to treat advanced NSCLC patients harboring EGFR mutations.