A Study to Evaluate the Antiviral Activity and Safety of HH-003 Injection in Subjects With HBeAg-Negative Chronic Hepatitis B Treated With Nucleos(t)Ide Reverse Transcriptase Inhibitors

Inclusion Criteria: * Signed informed consent form; * Male or female aged from 18 to 65years (inclusively); * 18 kg/m\^2≤BMI≤32 kg/m\^2, body weight≥45 kg for men and ≥40 kg for women; * At screening, etiological, clinical, or pathological evidence indicates chronic hepatitis B virus infection for at least 6 months; and negative HBeAg for more than 6 months; 10 IU/mL≤HBsAg≤3000 IU/mL; HBV DNA≤20 IU/mL; ALT≤1×ULN; * Participants who have been on the treatment of nucleos(t)ide reverse transcriptase inhibitors (limited to entecavir \[ETV\], tenofovir disoproxil fumarate \[TDF\], or tenofovir alafenamide fumarate \[TAF\]) for at least 3 years (as judged by the investigator) at screening. Exclusion Criteria: * Females who are pregnant or lactating at screening; * History of alcoholic liver disease, non-alcoholic steatohepatitis, autoimmune liver disease, other hereditary liver disease, drug-induced liver disease or other clinically significant chronic liver disease induced by non-HBV infection; * History or presence of progressive liver fibrosis or cirrhosis, including but not limited to liver stiffness measurement \[LSM\] ≥ 9 kPa at screening, progressive liver fibrosis or cirrhosis (e.g., S ≥ 3 in GS score or METAVIR ≥ F3) by liver histopathology examination, according to the Consensus on the diagnosis and therapy of hepatic fibrosis \[2019\]; or the presence of ascites, hepatic encephalopathy, upper gastrointestinal bleeding, or esophageal and gastric varices. * History or presence of hepatocellular carcinoma, or alpha-fetoprotein (AFP) ≥ 50 ng/mL at screening; or suspicion of hepatocellular carcinoma indicated by liver ultrasound, CT, or MRI. * Use of antiviral therapy with interferon within 1 year prior to screening * Any of the following lab test results at screening: total bilirubin \>2xULN or direct bilirubin \>1.5xULN, hemoglobin \<120 g/L for males or \<110 g/L ro females, platelets count\<100,000/mm\^3 (100×10\^9/L), and absolute neutrophils count \<1,500/mm\^3 (1.5×10\^9/L), Serum albumin \< 35 g/L; international normalized ratio (INR) of prothrombin time \> 1.3; or estimated glomerular filtration rate (eGFR) \< 60 mL/min/1.73 m2.