This is a multicenter, open-label, phase Ib/II study of YL202 in combination with other anti-tumor therapies to Evaluate the Safety, Tolerability, and Efficacy in Patients with Advanced Solid Tumors

Inclusion Criteria:

1. Informed of the study before the start of the study and voluntarily sign their name and date in the informed consent form (ICF)
2. Able and willing to comply with protocol visits and procedures
3. Aged between 18 to 75 years
4. Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 or 1
5. Previously treated by standard treatment or have not been treated for metastatic setting;
6. Adequate organ and bone marrow function.
7. Have at least 1 extracranial measurable tumor lesion.
8. Adequate archival formalin-fixed paraffin embedded （FFPE） tissue from prior biopsy.

Exclusion Criteria:

1. With prior drug therapy targeting HER3 (including antibodies, antibody-drug conjugates [ADCs]), chimeric antigen receptor T-cell immunotherapy (CAR-T), and other drugs).
2. Previously intolerant to topoisomerase I inhibitors or ADC therapy composed of topoisomerase I inhibitors.
3. Are participating in another clinical study, unless it is an observational (non-interventional) clinical study or in the follow-up period of an interventional study.
4. The washout period from the previous anti-tumor therapy is insufficient before the first dose of the investigational product.
5. Patients who have received major surgery (excluding diagnostic surgery) within 4 weeks before the first dose of the investigational product or those who are expected to receive major surgery during the study.
6. Prior treatment with allogeneic bone marrow transplantation or solid organ transplantation.
7. Prior treatment with systemic steroids (prednisone > 10 mg/day or equivalent) or other immunosuppressive treatment within 2 weeks before the first dose of the investigational product.
8. Patients who have received any live vaccine within 4 weeks before the first dose of the investigational product or those who plan to receive live vaccine during the study period.
9. With meningeal metastasis or cancerous meningitis.
10. With brain metastasis or spinal cord compression.
11. Patients with uncontrolled or clinically significant cardiovascular diseases.
12. Clinically significant complicated pulmonary disorders.
13. Patients diagnosed with Gilbert syndrome.
14. Those with uncontrolled effusion in the third space requiring repeated drainage.
15. With a medical history of gastrointestinal perforation and/or fistula within 6 months before the first dose, or with active gastric and duodenal ulcers, ulcerative colitis, or other gastrointestinal diseases that may lead to hemorrhage or perforation according to the investigator.
16. With serious infection before the first dose.
17. With known human immunodeficiency virus (HIV) infection.
18. With active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.
19. With a medical history of any other primary malignancies within 5 years before the first dose of the investigational product.
20. Unrelieved toxicity of previous anti-tumor therapy.
21. With a history of severe hypersensitivity to inactive ingredients in the raw materials and drug product or other monoclonal antibodies.
22. Lactating women, or women who are confirmed pregnant via a pregnancy test within 3 days before the first dose.
23. With any diseases, medical conditions, organ system dysfunction, or social conditions that may interfere with the ability of subjects to sign the ICF, adversely affect the ability of subjects to cooperate and participate in the study, or affect the interpretation of study results, including but not limited to mental illness or substance/alcohol abuse, in the opinion of the investigator.