An Open-label, Multicenter, Phase II Clinical Study to Evaluate the Efficacy and Safety of LBL-024 in Combination With Other Drugs for the Treatment of Patients With Advanced Solid Tumour.

This trial is an open-label, multicenter, phase II clinical study of LBL-024 in combination with other drugs for the treatment of patients with locally advanced or metastatic adenocarcinoma of the gastric or gastroesophageal junction,to evaluate the efficacy and safety of LBL-024 combination therapy.

This study will have a safety run-in period in which a small number of subjects will be enrolled to receive LBL-024 combination therapy.After the subjects completed the 21-day safety observation, the sponsor and investigator jointly assessed the safety and tolerability of the combination drugs. If safety and tolerability are good, the extension study of combination administration will be continued, the subjects will be continued to be enrolled, and the randomized, open, positive control trial design will be adopted.Subjects who meet the criteria will be randomly assigned to the experimental group and the control group in a ratio of 2: 1.

This trial will enroll up to 110 subjects.

Inclusion Criteria:

1. Agree to follow the trial treatment regimen, visit schedule, laboratory test, and other requirements of the protocol, and voluntarily enroll in the study and sign the written informed consent.
2. Age ≥ 18 years at the time of signing the informed consent.
3. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1.
4. The expected survival time is at least 12 weeks.
5. According to the evaluation of RECIST 1.1 standard, the subjects enrolled have at least one measurable lesion.
6. Patients with histologically confirmed unresectable locally advanced or metastatic gastric/gastroesophageal junction (G/GEJ) adenocarcinoma.
7. There is adequate organ and bone marrow function,Conforms to laboratory test results.
8. Males with fertility and females of childbearing age are willing to take effective contraceptive measures From the signing of the informed consent form to within 6 months after the last administration of the trial drug (including abstinence, intrauterine device, various hormonal contraception, correct use of contraception Sets，etc）; Women of childbearing age include pre-menopausal women and women within 2 years after menopause. Women of childbearing age must have a negative pregnancy test within 7 days before the first trial drug is administered.

Exclusion Criteria:

1. Participation in clinical studies of antineoplastic agents within 4 weeks before the first use of study drug,or is expected to receive any other form of systemic anti-tumor therapy outside the protocol during the study.
2. Use of immunomodulatory drugs within 2 weeks before the first use of study drug,Including but not limited to thymopeptide, interleukins, interferon, etc.
3. Patients with active, or who have had and have the possibility of recurrence of autoimmune diseases.
4. Patients with clinically uncontrollable pleural effusion, pericardial effusion, ascites, and those requiring repeated drainage or medical intervention.
5. The patient has a Medical history of immunodeficiency, including HIV antibody positive.
6. Active hepatitis B or active hepatitis C.
7. Women during pregnancy or lactation.
8. The investigator believes that the subject has other conditions that may affect compliance or are not suitable for participating in this study.