A Study Investigating BG-60366 in Adults With Epidermal Growth Factor Receptor (EGFR)-Mutant Non-Small Cell Lung Cancer

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of NSCLC, carrying an EGFRactivating 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 ormetastatic disease, and either progressed or ineligible for currently availablestandard-of-care treatment (eg, platinum-based chemotherapy) after EGFR-TKItreatment

• Phase 1a safety expansion

• Documentation of EGFR resistance mutations (ie, C797s)

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

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

• Adequate organ function

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

Exclusion Criteria:

• Any previous histologic or cytologic evidence of small cell or combined smallcell/non-small cell disease in the archival tumor tissue or tumor biopsy beforeenrollment

• Symptomatic spinal cord compression

• Brain metastases which are symptomatic and/or requiring emergency treatment (eg,starting steroid, or stereotactic radiation/whole-brain radiation within 2 weeksbefore first dose of study drug)

• Prior treatment with fourth-generation EGFR-TKI, other CDAC/proteolysis-targetingchimeras (PROTAC) compounds targeting EGFR mutations, or other drugs with themechanism of action specifically targeting EGFR resistance mutations (eg, C797X) (except for the first- to third-generation EGFR-TKIs)

• Any history of interstitial lung disease (ILD) or ≥ Grade 2 noninfectiouspneumonitis ≤ 2 years before the first dose of study drug, or has currentILD/noninfectious pneumonitis, or where suspected active ILD/noninfectiouspneumonitis cannot be ruled out by imaging during screening

• Uncontrollable pleural effusion, pericardial effusion, or ascites requiring frequentdrainage

Note: Other protocol defined Inclusion/Exclusion criteria may apply.