Eligibility Criteria:
Inclusion Criteria:
* Histopathologically confirmed advanced ICC, or combined hepatocellular and cholangiocarcinoma (cHCC-CC, composition of cholangiocarcinoma \>50%). nonresectable or metastatic cholangiocarcinoma and are not eligible for curative resection, transplantation, or ablative therapies.
* Have at least one measurable lesion (in accordance with RECIST v1.1); the measurable lesion has a long diameter ≥ 10 mm or lymphadenopathy has a short diameter ≥ 15 mm in spiral CT scan.
* Child-Pugh Class: Grade A
* ECOG-PS score 0 or 1
* Life Expectancy of at least 3 months
* Have the required screening laboratory values
Exclusion Criteria:
* Extrahepatic cholangiocarcinoma (EHCC) and primary liver cancer. other active malignant tumors except for ICC within 3 years or simultaneously. Cured localized tumor, for example, basal cell carcinoma of skin, squamous cell carcinoma of skin, superficial bladder cancer, carcinoma in situ of prostate, carcinoma in situs of cervix, breast cancer in situ may be enrolled.
* Any active autoimmune disease or history of autoimmune disease and expected recurrence (including but not limited to autoimmune hepatitis, interstitial pneumonia, uveitis, enteritis, hypophysitis, vasculitis, nephritis, hyperthyroidism, hypothyroidism \[subjects that can be controlled with hormone replacement therapy only can be enrolled\]); subjects with skin diseases that does no need systemic treatment, for example, leukoderma, psoriasis, alopecia, those with controlled type I diabetes by insulin or those with asthma that has been completely resolved in childhood and with no need of any intervention can be enrolled; while subjects with asthma who need bronchodilator for medical intervention cannot be enrolled;
* Use of strong CYP3A4/CYP2C19 inducers, including rifampicin (and its analogues) and St. John's Wort, or strong CYP3A4/CYP2C19 inhibitors within two weeks prior to signing informed consent form.
* Previous treatment with other immune checkpoint inhibitors (include PD-1 antibody or other immunotherapy against PD-1/PD-L1), or previous use of Apatinib.
* Known history of serious allergy to any monoclonal antibody or Apatinib.
* Inability or unwilling to swallow tablets, malabsorption syndrome or any condition affecting gastrointestinal absorption.
* Previous or current presence of metastasis to central nervous system.
* Severe infection within 4 weeks prior to the start of study treatment, including but not limited to hospitalization for infection, bacteremia or complications of severe pneumonia; oral or intravenous therapeutic antibiotics within two weeks prior to the start of study treatment (for example, subjects who are given with preventive antibiotics for prevention of urinary tract infection or exacerbation of chronic obstructive pulmonary disease are eligible for participation in the study);
* Other factors that may affect the study results or lead to forced termination of the study early as judged by investigators, such as alcoholism, drug abuse, other serious diseases (including mental disorders) requiring concomitant therapy, with serious laboratory examination abnormality, with family or social factors, that may affect subject's safety.