Non-small cell lung cancer (NSCLC) is a common type of lung cancer where abnormal cells in the lungs grow out of control. The purpose of this study is to evaluate YL202 monotherapy versus Docetaxel in participants with locally advanced or metastatic non-squamous NSCLC with EGFR mutation who have failed to EGFR-TKI therapy and platinum-based chemotherapy.

Inclusion Criteria:

1. Males or females aged ≥18 to ≤75 years at the time of signing the ICF
2. Histologically or cytologically confirmed diagnosis of locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) with documented EGFR Exon 19 deletion or Exon21 L858R mutation.
3. Received one prior epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) therapy in the locally advanced, or metastatic setting, either as monotherapy or in combination with other agents; Received one prior platinum based chemotherapy in the locally advanced, or metastatic setting, either prior to TKI, in combination with TKI, or after TKI therapy.
4. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1.
5. At least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, that has not been previously irradiated.
6. Central nervous system (CNS) metastasis, these should be clinically asymptomatic or stable after definitive treatment.
7. Current, historical, or suspected interstitial lung disease (ILD)/pneumonitis.

Exclusion Criteria:

1. Histologically or cytologically confirmed presence of small cell lung cancer, neuroendocrine carcinoma, and carcinosarcoma components or squamous cell carcinoma components of more than 10%;
2. Other malignancies within 5 years prior to the first dose;
3. History of (noninfectious) interstitial lung disease (ILD) and current ILD
4. Prior HER3-targeted therapy; Prior treatment with any drug therapy targeting topoisomerase I inhibitor, including antibody-drug conjugates (ADCs);
5. Pregnant or lactating women;