Acquired resistance represents a bottleneck for effective molecular targeted therapy in lung cancer. Metabolic adaptation is a distinct hallmark of human lung cancer that might contribute to acquired resistance. In this study, we discovered a novel mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) mediated by IGF2BP3-dependent cross-talk between epigenetic modifications and metabolic reprogramming through the IGF2BP3-COX6B2 axis. IGF2BP3 was upregulated in patients with TKI-resistant non-small cell lung cancer, and high IGF2BP3 expression correlated with reduced overall sur-vival. Upregulated expression of the RNA binding protein IGF2BP3 in lung cancer cells reduced sensitivity to TKI treatment and exacerbated the development of drug resistance via promot-ing oxidative phosphorylation (OXPHOS). COX6B2 mRNA bound IGF2BP3, and COX6B2 was required for increased OXPHOS and acquired EGFR-TKI resistance mediated by IGF2BP3. Mechanistically, IGF2BP3 bound to the 30-untranslat-ed region of COX6B2 in an m6A-dependent manner to increase COX6B2 mRNA stability. Moreover, the IGF2BP3-COX6B2 axis regulated nicotinamide metabolism, which can alter OXPHOS and promote EGFR-TKI acquired resistance. Inhibition of OXPHOS with IACS-010759, a small-molecule inhibitor, resulted in strong growth suppression in vitro and in vivo in a gefitinib-resistant patient-derived xenograft model. Collectively,these findings suggest that metabolic reprogramming by the IGF2BP3-COX6B2 axis plays a critical role in TKI resistance and confers a targetable metabolic vulnerability to overcome acquired resistance to EGFR-TKIs in lung cancer. Significance: IGF2BP3 stabilizes COX6B2 to increase oxidative phosphorylation and to drive resistance to EGFR inhibitors in lung cancer, which provides a therapeutic strategy to overcome acquired resistance by targeting metabolic transitions.