Evaluating the Safety, Tolerability, Pharmacokinetics, Pharmacokinetics, and Preliminary Efficacy of FS-8002

Inclusion Criteria: 1. Patients with advanced solid tumors confirmed by histology or cytology who have failed or become intolerant to previous standard treatments, or who do not have a standard treatment regimen. Cohort 1 includes patients with advanced solid tumours confirmed by histology/cytology/imaging (limited exclusively to HCC), who have experienced treatment failure with standard therapy, are intolerant to it, or lack standardized therapeutic options; however enrollment allows unresectable/metastatic HCC patients without prior systemic anti-cancer therapies; Cohort 2 comprises locally advanced/unresectable/metastatic gastric/gastroesophageal junction adenocarcinoma (G/GEJA) patients confirmed via histological/cytological diagnosis whose initial line of immunotherapy combined with fluoropyrimidine + platinum-based chemotherapy has failed - excluding cases where the last administration occurred more than six months before recurrence during adjuvant/neoadjuvant settings; 2. According to the evaluation criteria of RECIST V1.1 or RANO 2.0 (GBM only), at least one measurable lesion is required: the selected target lesion has not been treated previously locally, or the selected target lesion is located in the previous local treatment area, but is determined to be disease progression through imaging investigation; 3. The subject has sufficient organ and bone marrow function; Exclusion Criteria: 1. Patients who have previously received TGF-β inhibitor therapy. previous treatment with bevacizumab or other VEGF or VEGFR-targeted drugs (only for patients with GBM); 2. Have received any experimental drug treatment within 4 weeks prior to the first administration of the investigational drug; 3. Have used any systemic anti-tumor therapy within 4 weeks or 5 half-lives (whichever is shorter) before the first administration of the study drug, including systemic chemotherapy, radiotherapy, immunotherapy, hormone therapy, targeted therapy (small molecule targeted drugs are within 2 weeks before the first administration), systemic immunomodulators (including but not limited to IFN, IL-2 and tumor necrosis factor \[TNF\]). Received Chinese herbal or proprietary Chinese medicines with anti-tumor effects within 2 weeks before the first administration;For patients with GBM: less than 12 weeks from the end of previous radiotherapy (unless the progressing lesion is located outside the high-dose zone or 80% isodose line irradiation field, or there is pathological evidence), less than 24 days from the last TMZ treatment, or less than 6 weeks from the last carmustine treatment; 4. Have used or are currently using aspirin (≥ 325 mg/day) or other anti-platelet aggregation drugs such as clopidogrel, dipyridamole, ticlopidine, and cilostazole, or full-dose anticoagulants or thrombolytics within 2 weeks prior to the first administration of the study drug; 5. Those who have received major surgical treatment or significant traumatic injury within 4 weeks before the first administration of the study drug, or those who have a history of fistula, gastrointestinal perforation, or tumor invasion of large blood vessels within 6 months before the first administration; or those who have intestinal obstruction during the screening period;