A Phase I/II Study of FG-M108 Plus FG-B901 in Advanced CLDN18.2-Positive Solid Tumors

Inclusion Criteria: * Voluntarily sign the informed consent form, understand the study, are willing to comply with and have the ability to complete all trial procedures; * Age 18-75 years (inclusive), any gender; * Have histologically or cytologically confirmed locally advanced or metastatic solid tumors, and have failed standard therapy, or are intolerant to standard therapy, or for whom standard therapy is not available; * CLDN18.2 positive (defined as ≥10% of tumor cells showing membrane staining ≥1+ by central laboratory IHC) * ECOG 0-1 * Expected survival ≥3 months; * Have at least one measurable tumor lesion according to RECIST 1.1 criteria; * Adequate cardiac, bone marrow, liver, renal function; Exclusion Criteria: * Have received a live vaccine within 3 months prior to the first dose; * Received radiotherapy within 4 weeks before the first dose * Received Chinese herbal medicine with antitumor indications within 2 weeks before the first dose * Previously received any therapy targeting CLDN18.2 * History of other malignancies within 3 years before the first dose * Experienced Grade ≥3 immune-related adverse events (irAEs) from prior immunotherapy or discontinued immunotherapy due to irAEs, or have irAEs from prior immunotherapy that the investigator judges to still have clinical impact * Toxicity from prior antitumor therapy has not recovered to NCI CTCAE v5.0 Grade 0-1 * History of severe allergic reactions, or hypersensitivity, or intolerance to any known component of the investigational products or other monoclonal antibodies * Have brain or leptomeningeal metastases with symptoms * Presence of clinically symptomatic body cavity effusions (pleural effusion, ascites, pericardial effusion, etc.) requiring local therapy or repeated drainage, or effusions that are poorly controlled per investigator judgment * Uncontrolled or clinically significant cardiovascular and cerebrovascular diseases * Clinically uncontrolled diseases such as diabetes, thyroid disorders (hormone replacement therapy does not affect enrollment), or other severe systemic diseases requiring systemic treatment * Active or progressive infection requiring systemic treatment within 2 weeks before the first dose * Known or suspected active autoimmune disease requiring systemic treatment * Pregnant or breastfeeding female participants * Known history of Hepatitis C or chronic active Hepatitis B