A LM-302 Combination With Other Anti-Tumor Therapies Phase ll Study

Inclusion Criteria: 1. Participants who are willing to participate in the study and sign the informed consent form (ICF) prior to any procedure. 2. Aged 18-80 years old (including boundary values) . 3. Eastern Cooperative Oncology Group (ECOG) performance status of0-1. 4. Life expectancy ≥ 3 months. 5. Participants with advanced gastrointestinal tumors diagnosed histologically and/or cytologically and who have failed or are intolerant to prior standard first-line therapy (imaging confirmation required) 6. CLDN18.2-positive subjects. 7. At least one measurable lesion. 8. Participants must show appropriate organ and marrow function in laboratory examinations within 7 days prior to the first dose. 9. Participants who are able to communicate well with investigators and understand and adhere to the requirements of this study. Exclusion Criteria: 1. Participants with known HER2-positive gastric cancer/adenocarcinoma of the gastroesophageal junction 2. Participants have participated in any other clinical trial within 28 days prior to 1st dosing of investigational medicinal product (IMP). 3. Participants with anti-tumor treatment within 21 days prior to 1st dosing of IMP. 4. Previous immunotherapy and grade ≥3 irAE or grade ≥2 immune-related myocarditis. (for cohorts treated with combination PD-1). 5. Any adverse event from prior anti-tumor therapy has not yet recovered to ≤ grade 1 of CTCAE v5.0. 6. Present peripheral sensory or motor neuropathy ≥ grade 2. 7. Participants with uncontrolled pain. 8. Participants with symptomatic/active central nervous system(CNS)metastases. 9. Participants who have uncontrollable third space effusion. 10. Participants with known hypersensitivity to antibody therapy. 11. Participants have treated with the same target. 12. Participants have received Strong inhibitor/strong inducer of CYP3A4 within 14 days prior to first dose. 13. Use of any live vaccines within 28 days prior to 1st dosing of IMP. 14. Participants with current or previous interstitial lung diseases or pneumonia requiring oral or intravenous glucocorticoids for adjuvant therapy. 15. Participants on anticoagulants, such as heparin and vitamin K antagonists. 16. Clinically uncontrollable persistent recurrent vomiting. 17. Uncontrollable/severe gastrointestinal bleeding, ulceration or diarrhea within 28 days prior to first dose of IMP. 18. Participants who received major surgery or interventional treatment within28 days prior to the first dosing of IMP. 19. Participants who have other cancers, other than the one treated in this trial, within 2 years prior to screening. 20. Participants who have severe cardiovascular disease. 21. Participants who have uncontrolled or severe illness. 22. Participants who take systemic corticosteroids (\> 10 mg daily prednisone equivalents) or other systemic immunosuppressive medications within 2 weeks prior to the first dosing of IMP. 23. Participants with a known history of autoimmune diseases. 24. Participants who have a history of immunodeficiency disease. 25. Participants with HIV infection, active HBV or HCV infection. 26. Child-bearing potential female who have positive results in pregnancy test within 7 days before the first dose or are lactating. 27. Participants who have a known psychiatric diseases or disorders that may affect compliance with the trial. 28. Participants who is judged as not eligible to participate in this study by the investigator.