• Histologically or cytologically confirmed diagnosis of NSCLC, carrying an EGFR activating mutation prior to receiving standard EGFR-tyrosine kinase inhibitor (EGFR-TKI)

• Phase 1a general inclusion criteria:

⁃ Disease progression on prior third-generation EGFR-TKI for advanced or metastatic disease, and either progressed or ineligible for currently available standard-of-care treatment (eg, platinum-based chemotherapy) after EGFR-TKI treatment

• Phase 1a safety expansion

⁃ Documentation of EGFR resistance mutations (ie, C797s)

• At least ≥ 1 evaluable lesion (for Phase 1a Dose Escalation) or at least ≥ 1 measurable lesion (for Phase 1a Safety Expansion or Phase 1b Dose Expansion) per RECIST v1.1

• EGFR resistance mutations may be detected locally either from tumor tissue or circulating tumor DNA (ctDNA) in blood, and samples used for detection of resistance mutations must be collected after progression on the most recent systemic antitumor treatment

• Adequate organ function

• Stable Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 1