Combined Therapy Using Oxaliplatin and Gemcitabine Chemotherapy, Lenvatinib and PD1 Antibody (JS001) for Patients With Advanced and Unresectable Intrahepatic Cholangiocarcinoma

Inclusion Criteria: 1. The patient must be required to sign an informed consent form; 2. age 18-75 years old, male or female; 3. Eastern Cooperative Oncology Group (ECOG) fitness status score (PS score) 0; 4. Child-Pugh score A; 5. Histopathologically confirmed intrahepatic cholangiocarcinoma; consent to provide previously stored tumor tissue specimens or fresh biopsy tumor lesions; 6. unresectable ICC patients; 7. Functional indicators of vital organs meet the following requirements a Neutrophils ≥1.5\*109/L; platelets≥100\*109/L; hemoglobin≥9g/dl; serum albumin≥3g/dl; b Thyroid stimulating hormone (TSH) ≤ 1 times the upper limit of normal value(ULN), T3, T4 are in the normal range; c bilirubin ≤ 1.5 times ULN; Alanine aminotransferase （ALT） and Aspartate aminotransferase （AST） ≤ 1.5 times ULN; d serum creatinine ≤ 1.5 ULN, creatinine clearance rate ≥ 60ml / min; 8. The subject has at least 1 measurable liver lesion or non-liver lesion (according to RECIST 1.1); 9. Non-lactating or pregnant women, contraception during or after 3 months of treatment. Exclusion Criteria: 1. pathological diagnosis of hepatocellular carcinoma, mixed liver cancer and other non-cholangiocarcinoma malignant tumor components; 2. patients who have received previous treatment with PD1 antibody, programmed death ligand -1 （PDL1） antibody or cytotoxic T lymphocyte-associated antigen-4 （CTLA4） antibody; 3. with other malignant tumors, except for fully treated non-melanoma skin cancer, cervical carcinoma in situ, and papillary thyroid carcinoma; 4. 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; 5. 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; 6. previous interstitial lung disease, or (non-infectious) pneumonia and need oral or intravenous steroid therapy; 7. Long-term systemic hormones (dose equivalent to \>10 mg prednisone/day) or any other form of immunosuppressive therapy are required. Subjects using inhaled or topical corticosteroids may be enrolled; 8. severe cardiopulmonary and renal dysfunction; 9. suffering from high blood pressure, and can not be well controlled by antihypertensive drugs (systolic blood pressure ≥140mmHg or diastolic blood pressure ≥90mmHg); 10. abnormal blood coagulation (PT\>14s), with bleeding tendency or receiving thrombolytic or anticoagulant therapy; 11. hepatitis B virus （HBV） DNA\>2000 copies/ml, hepatitis C virus （HCV） RNA\>1000; 12. Significant clinically significant bleeding symptoms or a clear tendency to appear within 3 months prior to enrollment; 13. active infections requiring systemic treatment; 14. Human immunodeficiency virus (HIV) positive; 15. History of psychotropic substance abuse, alcohol abuse or drug abuse; 16. has a history of allergy to platinum; 17. 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.