• Patients who participate voluntarily, sign informed consent form (ICF), and will be able to follow the study procedures;

• Aged ≥ 18 years;

• Patients who are histologically or cytologically diagnosed with EGFR mutation and have unresectable locally advanced or recurrent/metastatic NSCLC;

• EGFR mutation requirements:

• Dose escalation phase (phase 1a): NSCLC patients who have progressed after standard EGFR-TKI treatment or cannot tolerate standard of care;

• Cohort expansion phase (phase 1b):

‣ Cohort 1: advanced NSCLC patients who have progressed after treatment with third-generation EGFR-TKIs and have EGFR C797S mutation.

‣ Cohort 2: advanced NSCLC patients who have progressed after standard EGFR-TKI treatment but have no other additional driver gene mutation(s).

‣ Cohort 3: advanced NSCLC patients who have progressed after EGFR-TKI treatment and have T790M mutation.

‣ Cohort 4: patients with locally progressed, unresectable or recurrent metastatic NSCLC who are naive to EGFR-TKI treatment and have 19del or 21L858R mutation among EGFR sensitive mutations.

• Patients who agree to provide tumor samples (fresh tissues or archived samples) for analysis of EGFR gene.

• Dose escalation phase: tumor samples collected from the progression site of disease during or after PD after the last TKI treatment should be provided for new genetic testing The subjects who fail to provide tumor samples will be allowed to enroll only after communication and consultation with the sponsor.

• Cohort expansion phase:

• Cohort1: tumor samples collected from the progression site of disease during or after PD after the last TKI treatment should be provided for genetic testing at central laboratory.

• Cohorts 2 and 3: tumor samples collected from the progression site of disease during or after PD after the last TKI treatment should be provided for genetic testing. The genetic testing will be exempted if subjects have the test results meeting the above requirements before their enrollment.

• Cohort 4: tumor samples collected from the progression site of disease during or after PD after the last treatment should be provided for genetic testing (of EGFR mutation); and if subjects are treatment-naive, they will be required to provide the tumor samples only during the screen period. The genetic testing will be exempted if subjects have the test results meeting the above requirements before their enrollment.

• ECOG ≤ 1 point (for details, refer to Appendix 2 ECOG performance status score);

• Life expectancy ≥ 12 weeks;

• Patients who have been diagnosed according to RECIST v1.1 and have measurable lesions as documented by computed tomography (CT) and/or magnetic resonance imaging (MRI) (note: subjects who do not have measurable lesions are allowed to be enrolled in phase 1a study). Note: a measurable lesion for response evaluation has to meet the following criteria: a) it is not in an area that has been involved in prior radiotherapy, or b) there is notable radiographic evidence of progression after the completion of radiotherapy and before study enrollment;

• Patients who have adequate organ functions and meet the following criteria:

∙ Hematology:

∙ Absolute neutrophil count ≥ 1.5 × 109/L; platelet count ≥ 100 × 109/L; hemoglobin ≥ 90 g/L (no blood transfusion and no use of granulocyte colony stimulating factor in the 14 days prior to the screening);

‣ Coagulation:

∙ For patients who have not received anticoagulant therapy: international normalized ratio (INR) of prothrombin time and partial thromboplastin time ≤ 1.5 × ULN;

‣ Liver:

∙ Alanine aminotransferase (AST) or alanine aminotransferase (ALT) ≤ 3.0 × ULN. For patients with liver metastases: ALT and AST ≤ 5 × ULN, total bilirubin ≤ 1.5 × ULN. For patients with Gilbert syndrome: conjugated bilirubin within normal range;

‣ Kidney:

• Serum creatinine ≤ 1.5 × ULN, or creatinine clearance ≥ 50 mL/min (calculated according to Cockcroft-Gault formula, refer to Appendix 4 Creatinine clearance calculation formula).

⁃ All acute toxic reactions arising from prior antineoplastic therapy or surgery have resolved to baseline or reduced in severity to ≤ Grade 1 according to NCI CTCAE V5.0 (except for alopecia or other toxicities which, in the opinion of the investigator, pose no safety risk to the patient);

⁃ Patients (both female and male) who agree to take effective contraceptive measures from their signing of ICF to 6 months after the last dose of the study drug. For women of childbearing potential: negative serum pregnancy test result in 7 days prior to the start of treatment is required.