• Patients should understand, sign, and date the written informed consent form prior to screening.

• Male or female aged 18 years or older.

• Patients with histologically or cytologically confirmed locally advanced (and not a candidate for definitive therapy) or metastatic NSCLC.

• Cohort-specific inclusion criteria:

∙ For the escalation part (except for the RDE confirmation part), patients have progressed on, rejected, or are intolerant of standard therapy, or for whom no standard therapy exists

‣ For RDE confirmation in the escalation part: same as Cohort 1 in the expansion part

‣ For the expansion part, patients have documented EGFR in-frame exon 20 insertion mutations confirmed by certificated local laboratories; and must also meet all criteria for the cohort in which their entry is proposed.

• Patients must have at least one measurable target lesion according to RECIST v1.1

• ECOG performance status 0 or 1

• 7\. Life expectancy ≥3 months

• Adequate organ function and bone marrow function.

• Electrolyte: magnesium within 0.85 to 1.25 × institutional normal limits, sodium ≥130 mmol/L, potassium within institutional normal limits

⁃ Adequately controlled blood pressure (BP) with or without antihypertensive medications, defined as BP ≤150/90 mmHg at screening and no change in antihypertensive medications within 1 week prior to the Cycle1 Day1.

⁃ For patients participating in food effect exploration part:

• Be able to eat a standardized high-fat meal within 30 minutes

∙ Be able to fast for 10 hours.

⁃ Non-surgically sterilized male or female patients of childbearing potential must agree to use highly effective methods of birth control during the study treatment and for approximately 6 months after the last dose of study drug. A condom is also required to be used by vasectomized men to prevent delivery of the drug via seminal fluid.