The main objective of the study will be to evaluate the efficacy of sutetinib maleate capsules in participants with locally advanced or metastatic non-small cell lung cancer NSCLC (uncommon EGFR mutations only).

Sutetinib is an investigational irreversible EGFR tyrosine kinase inhibitor. EGFR is a gene that makes a protein that is involved in cell growth and cell survival. Mutated (changed) forms of the EGFR gene and protein have been found in some types of cancer, including non-small cell lung cancer. These changes may cause cancer cells to grow and spread in the body. The purpose of this study is to explore how effective sutetinib maleate capsules are for the treatment of patients with locally advanced or metastatic NSCLC with uncommon EGFR mutations.

Inclusion Criteria:

1. Age 18 years old and above, male or female
2. Histopathological and/or cytopathological confirmation of locally advanced or metastatic NSCLC
3. Confirmation that the tumor harbors an uncommon epidermal growth factor receptor (EGFR) mutation (tumor tissue biopsy)
4. At least one measurable lesion
5. Eastern Cooperative Oncology Group (ECOG) score of 0, 1, or 2
6. A minimum life expectancy of > 3 months
7. Adequate bone marrow reserve, hepatic, renal, and coagulation function

Other inclusion criteria apply for participating in the study.

Exclusion Criteria:

1. Participant ever used the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR TKI) for anti-tumor therapy prior to enrollment (Cohort 1), or second generation EGFR TKI (Cohort 2)
2. Any systemic anti-tumor therapy such as chemotherapy and radiation therapy (including curative radiotherapy or spinal radiotherapy portion >30%) used within 3 weeks prior to enrollment; immunotherapy within 4 weeks; any palliative radiotherapy for non-target lesions used to relieve symptoms and traditional Chinese medicines indicated for the tumor within 2 weeks prior to enrollment; Cohort 2: any EGFR TKIs within 5 half-lives.
3. Use or intake of drugs or foods containing potent inhibitors or inducers of cytochrome P450 isozyme 3A4 (CYP3A4) within 14 days or 5 half-lives, whichever is the longer, prior to enrollment
4. Surgical operation (excluding aspiration biopsy) of main organs or a significant injury within 4 weeks prior to enrollment
5. Any unresolved toxicities from prior therapy greater than National Cancer Institute-Common Terminology Criteria for Adverse Events Version 5.0 (NCI-CTCAEv5.0) Grade 1, at the time of screening except for alopecia
6. Inability to swallow the study medication, any seriously (NCI-CTCAEv5.0 ≥ Grade 3) chronic gastrointestinal disorder, malabsorption syndrome or any other conditions with influence on gastrointestinal absorption
7. Active central nervous system metastases
8. Any active infection which has not been controlled at screening

Other exclusion criteria apply for participating in the Study.