Clinical Study on Intraluminal Injection of FOLactis

Inclusion Criteria:

• Age range from 18 to 80 years old, both male and female;

• Eastern Cooperative Oncology Group Performance Status score 0-2 poinRecurrent ormetastatic solid tumors confirmed by pathology (including but not limited topancreatic cancer, colorectal cancer, lung cancer, liver cancer, cholangiocarcinoma,gastrointestinal stromal tumor, head and neck tumor, gastric cancer, bone and softtissue sarcoma, neuroendocrine tumor, etc.);

• Malignant pleural/abdominal effusion confirmed by pathology;

• Expected survival time ≥ 12 weeks;

• The main organ function and bone marrow function are normal, meeting the followingrequirements:

1. Hemoglobin ≥ 80 g/L (no blood transfusion within 14 days);

2. Absolute neutrophil count ≥ 1.5 × 109/L, and white blood cell count ≥ 3 × 109/L;

3. Platelet count ≥ 90 × 109/L;

4. If there is no liver metastasis, total bilirubin<1.5 × ULN; If there is livermetastasis or Gilbert syndrome in patients with high indirect bilirubinemia,total bilirubin<3 × ULN;

5. If there is no confirmed liver metastasis, AST and ALT<2.5 × ULN; If there isconfirmed liver metastasis, AST and ALT<5 × ULN;

6. Serum creatinine ≤ 1.5 × The upper limit of normal value (ULN) and thecreatinine clearance rate calculated by the Cockroft Fault formula * are ≥ 30mL/min;

7. Left ventricular ejection fraction (LVEF) ≥ 50%;

8. International standardized ratio (INR)<1.5, and activated partial prothrombintime (APTT)<1.5 × ULN.

• The interval between previous anti-tumor therapy and the first administration ofthis trial is ≥ 4 weeks, and the toxicity related to anti-tumor therapy has returnedto ≤ 1 level (excluding hair loss, vitiligo, stable hypothyroidism after hormonereplacement therapy, etc.);

• Women of childbearing age must undergo a negative pregnancy test (serum or urine)within 14 days before enrollment, and voluntarily use appropriate methods ofcontraception during the observation period and within 3 months after the lastadministration of the study drug; For males, surgical sterilization or agreement touse appropriate methods of contraception during observation and within 3 monthsafter the last administration of the study medication should be considered;

• Those who voluntarily participate and sign an informed consent form, and are willingto follow the experimental treatment plan and visit plan;

• Agree to provide blood samples, pleural/ascitic fluid samples, and histologicalspecimens.

Exclusion Criteria:

• Within 4 weeks prior to enrollment, major surgeries were performed (excludingoutpatient minor surgeries such as placement of vascular pathways);

• Even after medication treatment, hypertension is still not well controlled (continuous increase in systolic blood pressure ≥ 150mm Hg or diastolic bloodpressure ≥ 100mmHg);

• Suffering from uncontrollable clinical symptoms or diseases of the heart, including: (1) NYHA II and above heart failure; (2) Unstable angina pectoris; (3) Haveexperienced myocardial infarction within 1 year; (4) Patients with clinicallysignificant supraventricular or ventricular arrhythmias who require clinicalintervention;

• Having any history of active autoimmune diseases or autoimmune diseases (such asinterstitial pneumonia, uveitis, enteritis, hepatitis, pituitary inflammation,vasculitis, myocarditis, nephritis, hyperthyroidism, hypothyroidism (which can beincluded after hormone replacement therapy);

• The patient is currently using immunosuppressive agents or systemic hormone therapyto achieve immunosuppressive effects (dosage>10mg/day prednisone or othertherapeutic hormones), and continues to use them within 2 weeks before enrollment;

• Has experienced severe allergic reactions to other monoclonal antibodies; Abnormalcoagulation function (INR>2.0, PT>16s), with bleeding tendency or undergoingthrombolytic or anticoagulant treatment, allowing prophylactic use of low-doseaspirin and low molecular weight heparin;

• HIV positive; HCV positive; Uncontrolled active hepatitis B;

• Severe infection (such as requiring intravenous drip of antibiotics, antifungal orantiviral drugs) within 2 weeks before the first medication, or unexplainedfever>38.5 ℃ during screening/before the first medication;

• Arterial/venous thrombotic events that occurred within 6 months prior to enrollment,such as cerebrovascular accidents (including temporary ischemic attacks, cerebralhemorrhage, cerebral infarction), deep vein thrombosis, and pulmonary embolism;

• Known to be allergic to any investigational drug;

• Pregnant and lactating patients, as well as those with reproductive ability, areunwilling to take effective contraceptive measures;

• Has a clear history of neurological or mental disorders, including epilepsy anddementia;

• Other situations that the researchers believe are not suitable for inclusion.Including but not limited to factors such as family or society, which can affect thesafety of the subjects or the collection of data and samples.