Combination of IV Ascorbic Acid and Adebrelimab in Metastatic Colorectal Cancer

Inclusion Criteria: * Age≥18 years, ≤75 years; Histologically proven peritoneal metastatic adenocarcinoma of colorectal cancer, unresectable metastatic disease; IHC confirmed strong positive GLUT3; measurable disease; Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1; Life expectancy of at least 12 weeks; ANC ≥1,500/mm3; Hemoglobin \> 8g/dL; platelet ≥ 100,000/mm3; Laboratory at baseline evaluation for inclusion in the study: creatinine ≤1.5X upper limit \[if the creatinine is elevated, but ≤1.5X the ULN, a 24 hour creatinine clearance will be obtained, Creatinine clearance \> 50 mL/min (calculated according to Cockroft and Gault)\]; Transaminase (AST/ALT) ≤2.5X upper limit of normal and bilirubin levels ≤1.5X upper limit of normal without liver metastasis; Transaminase (AST/ALT) ≤5X upper limit of normal and bilirubin levels ≤1.5X upper limit of normal with liver metastasis; Written informed consent Exclusion Criteria: * Prior treatment for metastatic disease (adjuvant therapy with fluoropyrimidines +/-oxaliplatin based regimens allowed if stopped 12 months prior to registration on study); Surgery (excluding diagnostic biopsy) or irradiation within 3 weeks prior to study entry; Administration of any investigational drug or agent/procedure, i.e. participation in another trial within 4 weeks before beginning treatment; Concurrent chronic systemic immune therapy, chemotherapy, radiation therapy (palliative radiation therapy allowed) or hormone therapy not indicated in the study protocol; Brain metastasis (known or suspected); Pregnant or lactating women; Other uncontrolled concomitant illness, including serious uncontrolled intercurrent infection; Known allergy or any other adverse reaction to any of the drugs or to any related compound; Previous (within 5 years) or concurrent malignancies at other sites with the exception of surgically cured or adequately treated carcinoma in-situ of the cervix and basal cell carcinoma of the skin; Patients with low or moderate expression of GLUT3.