Toripalimab Plus Lenvatinib as Second-line Treatment in Advanced Biliary Tract Cancers

Inclusion Criteria: Subjects must meet all of the following criteria * Subjects volunteer to participate in the study and agree to sign the informed consent with good compliance and follow-up. * Subjects are 18 years old or older when signing the informed consent and gender is not limited. * Subjects were diagnosed with advanced biliary tract cancers by imaging and histological examination, including intrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, common bile duct cancer and gallbladder cancer. Advanced biliary tract cancers refer to unresectable, recurrent, locally advanced and metastatic lesions which are defined as stage IIIA or above according to the 8th AJCC stage system. * The disease is not suitable for radical surgery and/or topical treatment, or disease progression occurs after surgery and/or local treatment, including lesion resection, ablation, transcatheter arterial chemoembolization (TACE), hepatic arterial infusion chemotherapy (HAIC), radiotherapy at least 4 weeks before the baseline assessment. All acute toxic effects of local treatment must be ≤ CTCAE 5.0 Level 1. * Patients are intolerant or fail after first-line systemic treatment (gemcitabine or platinum based regimen) and require palliative treatment. The first-line system treatment failure was ≥ 1 month before enrollment in this study (signing informed consent) and adverse events are controlled (NCI-CTCAE ≤ Grade Ⅰ). i) Definition of systemic treatment: Gemcitabine or platinum based regimen for more than 1 cycle. Adjuvant chemotherapy based on gemcitabine or platinum is considered as first-line treatment if recurrence occur during or after 6 months adjuvant chemotherapy sequential to tumor resection. ii) Definition of treatment failure: Disease progression occur during treatment or in 6 months after the last cycle. iii) Definition of intolerance: Grade ≥IV hematologic toxicity; grade ≥III toxicity of liver, kidney and skin; grade ≥ II toxicity of heart, lung and brain. * Prior treatment must not include lenvatinib, PD-1 / PD-L1 antibodies or molecular targeted therapy for ≥ 14 days. * At least one measurable lesion (according to RECIST version 1.1): the measurable lesion has a long diameter ≥ 10 mm or lymphadenopathy has a short diameter ≥ 15 mm in spiral CT scan. * Blood pressure is controlled \<= 150/90 mmHg with no more than 3 antihypertensive drugs. * The ECOG score is 0-1 within 1 week before enrollment. * Estimated survival time ≥ 12 weeks. * Liver function assessment: Child-Pugh Grade A or mild Grade B (score ≤ 7).Only one of albumin and bilirubin is Child-Pugh score 2. * Patients with active hepatitis B and C need to receive relevant antiviral treatment. HBV DNA \<2000 IU/ml (10\^4 copies/ml) and HCV-RNA negative. * No more than 2 organs metastasis, including liver, lung, bone and brain. * Hematology and organ function are well based on the following laboratory results within 14 days prior to the treatment of this study: i) Whole blood cell examination (no blood transfusion within 14 days, no G-CSF use and no drugs use): Hb≥100g/L, ANC≥1.5×10\*9/L, PLT≥75×10\*9/L. ii) Biochemical examination (no ALB infused within 14 days): ALB≥30g/L, ALT, AST and ALP\<5×ULN, TBIL≤60 μmol/L, creatinine≤1.5×ULN or CCr \>50mL/min. iii) Coagulation function: International standardized ratio (INR) ≤ 1.5 × upper limit of normal (ULN), or activated partial thromboplastin time (APTT) ≤ 1.5 × ULN; or PT ≤ULN + 4s. * No active autoimmune diseases that require systemic therapy in the past 2 years (note: active state means requiring disease modulators, corticosteroids or immunosuppressive drugs use). Alternative therapies, such as thyroxine, insulin or a physiological corticosteroid replacement therapy are not considered as systemic therapy. * Women with fertility agree to abstinence during the treatment period and at least 6 months after the last dose (avoiding heterosexual intercourse) or using a contraceptive method with an annual contraceptive failure rate \<1%. i)If a female patient has menstruation and not reached the postmenopausal state (continuously no menstruation ≥ 12 months and no other causes), and has not undergone sterilization by removing the ovaries and/or uterus), then the patient has fertility. ii) Contraceptive methods with a contraceptive failure rate \<1% include bilateral tubal ligation, male sterilization, hormonal contraceptives that inhibit ovulation, hormone-releasing intrauterine devices and copper intrauterine devices. iii) The reliability of sexual desire should be evaluated relative to the duration of the clinical trial and lifestyle of patient. Periodic abstinence (eg. calendar days, ovulation, symptomatic body temperature or post-ovulation methods) and in vitro ejaculation are unacceptable methods of contraception. * Male patients agree to abstinence (no heterosexual intercourse) or use of contraceptive measures and no sperm donation, as defined below: i) When a female partner has fertility, male patients must abstinence from sex during treatment and at least 6 months after the last dose of treatment, or use condoms and other contraceptive methods with contraceptive failure rate \<1%. At the same time, male patients must also agree not to donate sperm. ii) When a female partner is pregnant, the male patient must abstinence or using a condom during the treatment period and at least 6 months after the last dose of treatment to prevent the fetus from being affected by the study. iii) The reliability of sexual desire should be evaluated relative to the duration of the clinical trial and lifestyle of patient. Periodic abstinence (eg. calendar days, ovulation, symptomatic body temperature or post-ovulation methods) and in vitro ejaculation are unacceptable methods of contraception. * Tumor tissue must be available for biomarker analysis prior to the first dose of treatment, If not available, participants can consult the investigator for enrollment agreement. Exclusion Criteria: Subjects with one or more than one of the following criteria should be excluded * Patients meet with any of the following condition: Suitable for radical surgery; Or, without an assessment lesion after radical surgery; Or, never receive any first line treatment. * Patients who received first-line chemotherapy within 1 month when participating in the study. * Already known to be allergic or intolerant to recombinant humanized PD-1 monoclonal antibody drugs (or components) or lenvatinib. * Previously received with lenvatinib, or any anti-vascular endothelial growth factor (VEGF) or VEGF receptor targeted drug, or any anti-PD-1, anti-PD-L1 or anti-PD-L2 or CTLA-4 drug, including antibodies involved in JS001 clinical studies. * ECOG score ≥ 2 points. * Hepatic encephalopathy. * Histopathological result show mixed liver cancer, squamous cell carcinoma or sarcoma cell component. * More than 2 organs metastasis, including liver, lung, bone and brain. * pregnant women (positive pregnancy test before taking the drug) or lactating women. * Patients with bone metastases who had received palliative radiotherapy within 4 weeks before participating in the study (radiotherapy area\>5% bone marrow area). * Received any topical treatment within 4 weeks prior to the study, including but not limited to surgery, radiotherapy, hepatic artery embolization, TACE, hepatic artery perfusion, radiofrequency ablation, cryoablation or percutaneous ethanol injection. * Received any systemic anti-tumor treatment within 3 months prior to participation in the study, including but not limited to intravenous infused and/or oral chemotherapy, targeted drugs, antibody drugs, and traditional Chinese medicines known to have anticancer effects. * Patients are receiving approved or developing systemic anti-cancer therapies, including chemotherapy, bio-immunotherapy, targeted therapy, or traditional Chinese medicine therapy with clear indications. Treatment received 4 weeks before randomization is permitted. * Tumors or liver metastasis occupied more than 50% of liver volume. * Portal vein trunk (Vp4) or inferior cavity or atrium is affected by tumor thrombus. * Previous or existing grade 3 and above gastrointestinal fistula or non-gastrointestinal fistula (such as skin). * Factors affect lenvatinib use, such as inability to swallow, chronic diarrhea, intestinal obstruction, or other conditions that significantly affect drug intake and absorption. * Any \>1 grade (CTC-AE5.0) unresolved toxicity due to previous treatment or operation, except for hair loss, anemia, and hypothyroidism. * Ascites with clinical symptoms which requires abdominal puncture or drainage therapy, or Child-Pugh score \>2 points. * Hemoptysis within 4 weeks before the first medication. * Surgery was performed within 4 weeks prior to the trial and patients must be evaluated after wound healing. Or minor surgery within 7 days before the first medication, such as simple resection and biopsy. * Severe cardiovascular and cerebrovascular diseases, including but not limited to acute myocardial infarction, severe/unstable angina pectoris, cerebrovascular accident or transient ischemic attack, congestive heart failure and arrhythmias within 6 months before enrollment. * Thromboembolism (including stroke and / or transient ischemic attack) within 12 months. * Hypertension that cannot be controlled well with antihypertensive drugs (systolic blood pressure\> 150mmHg, diastolic blood pressure\> 100mmHg). * Active autoimmune disease or autoimmune disease within two years that may affect vital organ function or have/may require systemic immunosuppressive therapy. Type I diabetes, hypothyroidism requiring only hormone replacement, skin diseases that do not require systemic treatment (such as vitiligo, psoriasis, or hair loss) are allowed. * Subjects who need systemic treatment with corticosteroids (\>10 mg / day prednisone or its equivalent) or other immunosuppressive drugs within 30 days of study administration. In the absence of active autoimmune disease, inhaled or topical steroids are allowed. * Already known active central nervous system metastasis and/or cancerous meningitis. Subjects with stable brain metastases after previous treatment may participate as long as no radiologic evidence of progression lasts for at least four weeks prior to this trial and any neurological symptoms have returned to baseline, and no new or enlarged metastatic evidence in brain and no steroids use for at least 7 days prior to trial treatment. Cancer meningitis should be excluded regardless of clinical stability. * Liver function and renal dysfunction evidence: jaundice, ascites, and/or bilirubin ≥ 60 μmol/L, proteinuria (\> 3.5g /24 hours), or renal failure requiring blood dialysis or peritoneal dialysis. * Persistent \>2 grade (CTC-AE5.0) infection. * Vaccination of any live virus vaccine within 4 weeks prior to this study. * Biliary obstruction after clinical intervention is not remissed or needs anti-infective treatment 14 days before the first medication. * History of allogeneic tissue transplantation or solid organ transplantation. * History of active tuberculosis, such as mycobacterium tuberculosis. * Female patients who are pregnant, breastfeeding or refuse contraception. * Gastrointestinal bleeding history in the past 6 months or tendency to gastrointestinal bleeding, such as esophageal varices, local active ulceration lesions, fecal occult blood ≥ (++) (gastroscopy is required when fecal occult blood is (+)). Evidence or history of ≥3 grade (CTC-AE5.0) bleeding events. * History of human immunodeficiency virus infection. * History of hepatitis B virus or hepatitis C virus infection, and not receive regular treatment. * Severe non-healing wounds, ulcers or fractures. * With other malignant tumors within 5 years. * Previous and current evidence of pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, radiation pneumonitis, drug-associated pneumonia and severe impairment of lung function. * Received a potent CYP3A4 inhibitor treatment within 7 days prior to the study, or received a potent CYP3A4 inducer within 12 days prior to the study. * There exists drug abuse, or any medical, psychological or social condition which might affect the study, the compliance or even the safety of patients. * Informed consent can not be signed for mental or medical instability. * Patients participate in another clinical study at the same time. * Patients are unsuitable for participation in this research after comprehensive assessment by the researchers.