Low-dose Gemcitabine and Cisplatin and PD-1/PD-L1 Antibody Therapy in Intrahepatic Cholangiocarcinoma

Inclusion Criteria: 1. Age ≥ 18 years old, male or female; 2. Histopathologically confirmed intrahepatic cholangiocarcinoma; 3. TNM Staging≥Stage II (American Joint Committee on Cancer Prognostic Groups) 4. Presence of at least one measurable lesion assessed using the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST version 1.1); 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 6. Child-Pugh score ≤ 7; 7. Adequate organ function (neutrophil count of ≥1.5×10\^9 cells/L, hemoglobin concentrations of ≥90 g/L, platelet cell count of ≥100×10\^9 cells/L, bilirubin ≤1.5×ULN, Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) ≤ 5×ULN, serum creatinine ≤ 1.5 x ULN, Thyroid stimulating hormone (TSH) ≤ 1 x ULN; 8. The patient must be required to sign an informed consent form; Exclusion Criteria: 1. Patients who have received previous treatment with interventional therapy, radiotherapy, ablation, chemotherapy, targeted therapy, immunotherapy (PD-1, PD-L1, CLTA-4 antibody, etc), or surgery within the last 2 months; 2. Patients with other malignant tumors within the last 5 years, except for cured non-melanoma skin cancer, cervical carcinoma in situ, and papillary thyroid carcinoma; 3. Active tuberculosis infection. Patients with active tuberculosis infection within 1 year prior to enrollment; had a history of active tuberculosis infection more than 1 year before enrollment, did not receive formal anti-tuberculosis treatment or tuberculosis is still active; 4. Active infection requiring systemic therapy; 5. Human immunodeficiency virus (HIV) positive; 6. Have an active, known, or suspected autoimmune disease. Subjects who require only hormone replacement therapy for hypothyroidism and skin diseases that do not require systemic therapy may be enrolled; 7. Suffering from high blood pressure, and can not be well controlled by antihypertensive drugs (systolic blood pressure ≥140mmHg or diastolic blood pressure ≥90mmHg); 8. Abnormal blood coagulation (INR \>1.5, or PT\>ULN+4s, or APTT \>1.5 x ULN), with a bleeding tendency or receiving thrombolytic or anticoagulant therapy; 9. Pregnant or lactating women; 10. Participated in other trials within the last 4 weeks; 11. Has a history of allergy to platinum; 12. Other factors that may influence the safety of the subject or the compliance of the test by the investigator. Serious illnesses (including mental illness), severe laboratory tests, or other family or social factors that require combined treatment.