Exploring the safety and efficacy of the therapy combining immune checkpoint inhibitors (anti-PD-L1 monoclonal antibody, ASC22) and pegylated interferon alfa (Peg-IFNα) in patients with CHB. Exploring new combination therapeutic schemes for hepatitis B cure, and raising the overall clinical cure rate to more than 50% without screening specific advantageous groups.

Inclusion Criteria:

1. Sign the informed consent form before inclusion and be able to complete the study according to the study requirements
2. From inclusion to 30 days after the last administration of the study drug, male subjects or female subjects of childbearing age are willing to voluntarily take effective contraceptive measures
3. 18-70 years old. The weight of male subjects is not less than 45 kg, and the weight of female subjects is not less than 40 kg. Body mass index (BMI) is within the range of 18-32 kg/m2
4. Serum HBsAg<100 IU/mL
5. HBV DNA<20 IU/mL
6. HBeAg-negative

Exclusion Criteria:

1. A history of allergy, or who are suspected by the researcher to be allergic to the active ingredient of the drug under study or its excipients
2. Use of inhibitors, inducers or substrates of CYP3A4 within 28 days before enrollment
3. Systematical use of immunosuppressants, immunomodulators (thymosin) and cytotoxic drugs within 6 months before enrollment, or vaccination of live attenuated vaccine within 1 month before enrollment
4. Acute infection within 2 weeks before enrollment which requires intravenous antibiotic treatment, or existing infection which requires anti-infection treatment when enrollment
5. Clinically significant acute and chronic liver disease not caused by HBV infection (judged by reseachers)
6. Confirmed or suspected decompensated cirrhosis, including but not limited to: hepatic encephalopathy, hepatorenal syndrome, bleeding from esophageal varices, splenomegaly, ascites, etc, or evidence of progressive liver fibrosis
7. Primary liver cancer, or alpha-fetoprotein (AFP) is greater than 50 ug/L or imaging suggests the possibility of malignant liver lesions, or other malignant tumors or a history of other malignant tumors within 5 years before enrollment (except that the malignant tumors have been completely relieved after treatment and patients have not received additional medical or surgical intervention within 3 years before screening)
8. A history of pathological fracture or osteoporosis
9. Gastrointestinal dysfunction or gastrointestinal diseases that might affect the absorption of oral drugs, such as severe gastric ulcer, erosive gastritis, partial gastrectomy, and persistent gastrointestinal symptoms (such as nausea, vomiting, or diarrhea) >2 grades
10. Serious diseases of circulatory, respiratory, urinary, blood, metabolic, immune, mental, neurological, renal and other systems
11. Major trauma or major surgery within 3 months before enrollment, or planned surgery during the study period
12. Blood donation/loss ≥ 400 mL within 3 months before enrollment, or given a blood transfusion within 3 months before enrollment, or blood donation/loss ≥ 200 mL within 1 month before enrollment
13. Platelet count<90 × 10^9/L, white blood cell count<3.0 × 10^9/L, neutrophil count<1.3 × 10^9/L, total serum bilirubin>2 × ULN, albumin<30 g/L, creatinine clearance ≤ 60 mL/min (calculated by CKD-EPI formula), or international normalized ratio of prothrombin time (INR)>1.5 (unless receiving stable anticoagulant therapy)
14. HCV antibody (+), HIV antigen/antibody (+), or treponema pallidum antibody (+) and RPR test (+)
15. A history of continuous alcohol abuse within 3 years before enrollment (average daily alcohol consumption exceeds 20 gram)
16. A history of drug dependence or drug abuse within 1 year before enrollment
17. Those who have participated in clinical trials of other investigational drugs or medical devices and taken investigational drugs or used medical devices within 3 months before enrollment
18. Female in suckling period or pregnancy test (+) during screening
19. Subjects who are considered by the researcher to have other factors that are not suitable for the study