Gut Microbial Metabolites Inosine Combined With PD-1/PD-L1 Inhibitor for Patients With Malignant Advanced Solid Tumors

Inclusion Criteria: 1. Histopathologically confirmed unresectable locally advanced, recurrent or metastatic solid tumors 2. Age 18 years old - 75 years old 3. ECOG score of ≤ 2 4. Time to end of palliative treatment for localized lesions (non-target lesions) was \>3 weeks from randomization start time, At least one measurable lesion or assessable lesion according to RECIST v1.1 5. Can provide archived pathological tissues or fresh pathological tissues for PD-L1, MMR/MSI, TMB testing within 6 months from the signing of the informed consent for screening and can obtain the test results 6. Adequate organ and bone marrow function, defined as follows: 1) Blood count: absolute neutrophil count (ANC) ≥ 1.5 × 109/L, platelet count (PLT) ≥ 100 × 109/L, hemoglobin level (HGB) ≥ 9.0 g/dL. 2) Liver function: patients without liver metastases require: serum total bilirubin (TBIL) ≤ 1.5 × upper limit of normal ( ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5×ULN. patients with liver metastases required: TBIL ≤1.5×ULN; ALT and AST ≤5×ULN. 3) renal function: creatinine clearance (Ccr) ≥50mL/min (calculated using the Cockcroft/Gault formula): female: Ccr = (140-years-old) × body weight (kg) × 0.85; men: Ccr = (140-years-old) × body weight (kg) × 1.00. 4) Adequate coagulation function, defined as international normalized ratio (INR) or prothrombin time (PT) ≤1.5 × ULN 7. Expected survival time ≥ 12 weeks 8. Female subjects of childbearing age or male subjects whose sexual partners are women of childbearing age are required to use effective contraception throughout the treatment period and for 6 months after the treatment period 9. Sign the written informed consent Exclusion Criteria: 1. Signs of active bleeding or perforation 2. History of intestinal obstruction or the following diseases: inflammatory bowel disease or extensive bowel resection, Crohn's disease, ulcerative colitis 3. Hepatic metastatic focal load of approximately 50% or more of the entire liver volume 4. Antibiotic was used within 2 weeks before study treatment 5. Received systemic antitumor therapy with herbs or immunomodulatory drugs (including thymidine, interferon, interleukin, etc.) within 2 weeks before the first dose. 6. immunosuppressive drugs was used within 4 weeks before study treatment, excluding topical glucocorticoids or physiologic doses of systemic glucocorticoids (i.e., no more than 10mg/day of prednisone or equivalent doses of other glucocorticoids) of nasal spray, inhalation, or other routes, or glucocorticoid for the prevention of contrast allergy 7. Interstitial lung disease requiring glucocorticoid therapy 8. Active, known or suspected autoimmune disease or history of the disease within the last 2 years (patients with vitiligo, psoriasis, alopecia or Grave's disease not requiring systemic treatment within the last 2 years, hypothyroidism requiring only thyroid hormone replacement therapy, and type I diabetes requiring only insulin replacement therapy may be enrolled) 9. Symptomatic congestive heart failure (New York Heart Association class -≥3) or symptomatic or poorly controlled arrhythmias 10. standard treatment could not uncontrollarterial hypertension (systolic blood pressure ≥ 160 or diastolic blood pressure ≥ 100). 11. Any arterial thromboembolic event, including myocardial infarction, unstable angina, cerebrovascular accident or transient ischemic attack, within 6 months prior to enrollment in treatment 12. History of deep vein thrombosis, pulmonary embolism, or any other serious thromboembolism within 3 months prior to enrollment 13. Known active tuberculosis 14. Known history of case type immunodeficiency virus infection 15. Positive hepatitis B surface antigen and peripheral blood hepatitis B virus deoxyribonucleic acid (HBV DNA) titer test ≥ 1×104 copies/mL (or HBV-DNA quantification ≥ 2000 units/ml); active hepatitis C 16. History of other primary malignancies, except: malignancies in complete remission for at least 5 years prior to enrollment and requiring no other treatment during the study period; adequately treated non-melanoma skin cancer or malignant freckled nevus with no evidence of disease recurrence; adequately treated carcinoma in situ with no evidence of disease recurrence 17. Patients who, in the judgment of the investigator, are otherwise likely to interfere with the conduct of the clinical study, who may not be able to comply with the protocol or who are unable to cooperate, or who are a risk to the study This study was approved by the Clinical Investigation Ethics Committee of Beijing Friendship Hospital, Capital Medical University, and was conducted in accordance with the Declaration of Helsinki. All patients signed informed consent forms for data collection and study purposes