A Study to Evaluate the Antiviral Activity and Immune Response of AHB-137 Injection in Participants With Chronic Hepatitis B (CHB)

This study is a single-center, open-label Phase II clinical study to evaluate the antiviral activity and immune responses of AHB-137 injection in participants with CHB treated with nucleos (t) ide analogues.

Inclusion Criteria: * Voluntarily participated in the study and signed an informed consent form; * Aged between 18 and 55 years at the time of signing the informed consent form; * Body mass index (BMI) within the range of 18-30 kg/ m2; * HBeAg negative or positive at screening; * HBsAg or HBV DNA positive for at least 6 months; * Have been on continuous nucleos(t)ide analogues antiviral therapy for more than 6 months prior to screening; * 100 IU/mL \< HBsAg ≤ 3000 IU/mL and HBV DNA \< 100 IU/mL at screening; * Alanine aminotransferase (ALT) ≤ 2 × upper limit of normal (ULN); * Effective contraception as required. Exclusion Criteria: * Clinically significant abnormalities other than a history of CHB infection; * Concomitant clinically significant other liver diseases; * Any serious infection other than CHB infection requiring intravenous anti-infective therapy within 1 month prior to screening; * Active hepatitis C, Human immunodeficiency virus (HIV) positive, syphilis positive; * Liver stiffness value (LSM) \> 9.0 kPa at screening; * Diagnosis or suspicion of hepatocellular carcinoma, or alpha-fetoprotein (AFP) concentration ≥ 20 ng/mL at screening; * Participants with confirmed or suspected hepatic decompensated hepatitis B cirrhosis; * Liver biopsy at screening assessed severity of activity ≥ G3 grade and/or fibrosis reaching S4 stage; * History of extrahepatic disease possibly related to HBV immune status; * Ongoing or taking any immunosuppressive medication within 3 months prior to screening. Those who have used immunomodulators and cytotoxic drugs within 6 months prior to the first dose, or have a history of vaccination within 1 month prior to screening or have a live vaccination plan during the trial; Continuous use of traditional Chinese medicine for more than 2 months within 1 year prior to screening, or within 1 month prior to screening; Ongoing use of anticoagulants, bleeding tendency or coagulopathy, or conditions that, in the opinion of the investigator, increase the risk of liver biopsy; * Receiving or using any interferon-containing therapy within 12 months prior to screening; * History of malignancy within 5 years prior to screening or being evaluated for possible malignancy; * Suspected history of allergy to any component of the study drug, or allergic constitution (multiple drug and food allergy, and judged by the investigator to be clinically significant); * Major trauma or major surgery within 3 months prior to screening, or planned surgery during the study; * Donation or blood loss ≥ 400 mL, or received blood transfusion within 12 weeks prior to screening; Or blood donation or blood loss ≥ 200 mL within 1 month prior to screening; * Participants who are participating in another clinical trial, or have not undergone a protocol-specified washout period prior to this study; * Received any antisense oligonucleotides (ASO) or using any small molecule interfering ribonucleic acid (siRNA) drug within 12 months prior to screening; * Participants with abnormal thyroid function judged by the investigator to be ineligible for enrollment; * Obviously abnormal laboratory test results; * History of vasculitis or signs and symptoms of underlying vasculitis; * Any other circumstance or condition that, in the opinion of the investigator, the participants are inappropriate for participation in the study.