SHR-A1904 Combinations in CLDN18.2-Positive Advanced Solid Tumor

Inclusion Criteria:

1. Age 18 to 75 years old (including boundary values);

2. Volunteer to participate in this clinical study and sign informed consent;

3. ECOG score 0-1;

4. Expected survival ≥3 months;

5. Pathologically confirmed locally advanced unresectable or metastatic solid tumors;

6. positive CLDN18.2 expression in tumor tissue;

7. There is at least one measurable lesion that meets the RECIST 1.1 criteria;

8. Adequate bone marrow and organ function.

Exclusion Criteria:

1. Plan to receive any other antitumor therapy during this trial; Received otherinvestigational drugs or treatments that are not on the market within 4 weeks priorto the first administration; Anti-tumor therapy, such as chemotherapy, radiotherapy,biotherapy, targeted therapy or immunotherapy, was received within 4 weeks beforethe first administration of the study drug. Palliative radiotherapy or local therapywithin 2 weeks before the first administration of the study drug; Had major surgeryother than diagnosis or biopsy within the 4 weeks prior to the first administrationor randomization and required elective surgery during the trial.

2. Stage III: HER2 expression in tumor tissue is positive.

3. The adverse reactions of previous anti-tumor therapy has not recovered to NCI-CTCAEv5.0 grade≤ 1.

4. Has ≥ grade 2 peripheral sensory neuropathy.

5. Has an allergic reaction to any of the components treated in this study, or areallergic to humanized monoclonal antibody products.

6. Has a history or current history of meningeal metastasis; or active brainmetastases.

7. Presence of dysphagia or other factors affecting the use of oral medications.

8. Additional malignancy within the five years prior to the first administration orrandomization.

9. Has an active autoimmune disease or a history of autoimmune disease.

10. Received systemic use of corticosteroids or other immunosuppressants forimmunosuppressive effects within 14 days prior to the first administration orrandomization.

11. Has a history of clinically significant lung disease.

12. Has serosal effusion ≥ grade 3 (based on NCI CTCAE5.0 criteria).

13. There was an active infection requiring systemic treatment within 2 weeks prior tothe first administration or randomization.

14. A history of immunodeficiency, including a positive HIV test; Presence of activehepatitis B or hepatitis C.

15. People who have previously received allogeneic hematopoietic stem celltransplantation or organ transplantation.

16. Has severe cardiovascular and cerebrovascular diseases.

17. Gastrointestinal perforation and/or gastrointestinal fistula within the last 6months prior to the first administration or randomization; Active gastrointestinalbleeding occurred 3 months before the first administration or randomization.

18. In the investigator's judgment, the subjects has other factors that could haveaffected the study results or led to the forced termination of the study.