Tilelizumab Combined With Nab-Paclitaxel for High-Risk Non-Muscle-Invasive Urothelial Bladder Carcinoma Which is Not Completely Resectable: a Multi-center Study

Inclusion Criteria:

1. Willing and able to provide written informed consent;
2. Ability to comply with the protocol;
3. Age ≥ 18 years;
4. High-risk non-muscle-invasive urothelial carcinoma or high-risk non-muscle-invasiveurothelial carcinoma as the main pathological component > 50%, difined as following: a. T1 b. High-grade Ta c.Carcinoma in situ(CIS);
5. Multi-point biopsy of bladder shows there are more than 2 section and over 3 points ofpathological specimens are diagnosed as above, meanwhile, the tumor has to bediagnosed as not completely resectable by at least 2 senior urologist;
6. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-2;
7. Agreed to provide tissue examination samples (for detection of PD-L1 expression, tumormutation load, IHC, detection of DNA and RNA, etc;)
8. Organ function level must meet the following requirements:

• Hematological indexes: neutrophil count >= 1.5x10^9/L, platelet count >= 80x10^9/L, hemoglobin >= 6.0 g/dl (can be maintained by blood transfusion);
• Liver function: total bilirubin <=1.5 ULN, alanine aminotransferase and aspartateaminotransferase <=2.5 ULN;

9. The subjects volunteered to join the study, signed informed consent, and had goodcompliance with follow-up;

Exclusion Criteria:

1. Receive live attenuated vaccine within 4 weeks before treatment or during the studyperiod;
2. Active, known or suspected autoimmune diseases;
3. History of primary immunodeficiency;
4. Known history of allogeneic organ transplantation and allogeneic hematopoietic stemcell transplantation;
5. Pregnant or lactating female patients;
6. Untreated acute or chronic active hepatitis B or hepatitis C infection. Under thecondition of monitoring the virus copy number of patients receiving antiviraltreatment, doctors can judge whether they are in line with the patients' individualconditions;
7. Prior use of immunosuppressive drugs within 4 weeks prior to the start of treatment,excluding nasal and inhaled corticosteroids or physiological doses of systemicsteroids (i.e. not more than 10 mg / day prednisolone or other corticosteroids withthe same physiological dose);
8. Known or suspected allergy to tislelizumab and albumin paclitaxel;
9. Have a clear history of active tuberculosis;
10. Received PD-1 / PD-L1 / CTLA-4 antibody or other immunotherapy in the past;
11. Participating in other clinical researchers;
12. Men with reproductive capacity or women who are likely to become pregnant do not takereliable contraceptive measures;
13. Uncontrolled concurrent diseases, including but not limited to:

• HIV infected (HIV antibody positive);
• Severe infection in active stage or poorly controlled;
• Evidence of serious or uncontrollable systemic diseases (such as severe mental,neurological, epilepsy or dementia, unstable or uncompensated respiratory,cardiovascular, liver or kidney diseases, uncontrolled hypertension [i.e.hypertension greater than or equal to CTCAE grade 2 after drug treatment]);
• Patients with active bleeding or new thrombotic disease