Study of QLS31905 and/or QL1706 Combination With Chemotherapy in the Advanced Malignant Solid Tumors

Inclusion Criteria:

• Subjects voluntarily participate in the study and sign the informed consent form;

• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;

• Expected survival time ≥ 3 months;

• Histologically or cytologically confirmed locally advanced unresectable ormetastatic solid tumors;

• No prior systemic anti-tumor treatment for locally advanced unresectable ormetastatic disease;

• Tumor tissue samples determined to be positive for Claudin18.2 byimmunohistochemistry (IHC);

• At least one measurable lesion per RECIST v1.1;

• Patients with adequate cardiac, liver, renal function, etc.

Exclusion Criteria:

• History of malignancies other than the target cancer within 5 years prior to thefirst dose of the investigational product ;

• Underwent major organ surgery (excluding needle biopsy) or had significant traumawithin 28 days prior to enrollment, or requires elective surgery during the study;

• Known central nervous system metastases;

• Patients with hepatitis B; patients with hepatitis C; patients who test positive forsyphilis, or patients with a known history of HIV or positive HIV screening test;Patients with a known history of psychoactive drug abuse, alcohol abuse, orsubstance abuse;

• Patients with added risks associated with the study or may interfere with theinterpretation of study results as determined by the investigator, or deemedunsuitable by the investigator and/or sponsor.