Studies at RP2D Cohort 1: no prior treatment for locally advanced or metastatic EGFRm NSCLC. Cohorts 2 and 3: must have had disease progression on treatment with an approved 1st or 2nd generation EGFR TKI. Patients who have been treated with a 3rd generation EGFR TKI are ineligible for this study. Patients may have had multiple lines of therapy; however, the last therapy prior to study treatment must have been an approved EGFR TKI and received within 6 weeks prior to study registration.