A Study of ALG-020572 Drug to Evaluate Safety, Tolerability, Pharmacokinetics and Pharmacodynamics After Single Doses in Healthy Volunteers and Multiple Doses in CHB Subjects

Inclusion Criteria for Healthy Subjects: 1. Male and Female between 18 and 55 years old 2. Female subjects must have a negative serum pregnancy test at screening 3. BMI 18.0 to 32.0 kg/m\^2 4. Subjects must have a 12-lead ECG that meets protocol criteria Inclusion Criteria for CHB Subjects: 1. Male and Female between 18 and 75 years old 2. Female subjects must have a negative serum pregnancy test at screening 3. BMI 18.0 to 35.0 kg/m\^2 4. For virally suppressed subjects, must be currently receiving HBV NA treatment for ≥6 months prior to screening. For currently not treated or treatment naïve subjects, must have never received treatment OR have not been on treatment within 6 months prior to randomization 5. Subjects must have a 12-lead ECG that meets protocol criteria Exclusion Criteria for Healthy Subjects: 1. Subjects with any current or previous illness that, in the opinion of the Investigator, might confound the results of the study or pose an additional risk in administering study drug to the subject or that could prevent, limit, or confound the protocol specified assessments or study results' interpretation 2. Subjects with a past history of cardiac arrhythmias, risk factors for Torsade de Pointes syndrome (e.g., hypokalemia, family history of long QT Syndrome) or history or clinical evidence at screening of significant or unstable cardiac disease etc. 3. Subjects with a history of clinically significant drug allergy 4. Subject with current or history of clinically significant (as determined by the Investigator) skin disease requiring intermittent or chronic treatment 5. Excessive use of alcohol defined as regular consumption of ≥14 units/week for women and ≥21 units/week for men 6. Unwilling to abstain from alcohol use for 48 hours prior to start of dosing through end of study follow up 7. Subjects with Hepatitis A, B, C, D, E or HIV-1/HIV-2 infection or acute infections such as SARS- CoV-2 infection 8. Subjects with renal dysfunction (e.g., estimated creatinine clearance \<90 mL/min/1.73 m\^2 at screening, calculated by the Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula) Exclusion Criteria for CHB Subjects: 1. Subjects with any current or previous illness that, in the opinion of the Investigator, might confound the results of the study or pose an additional risk in administering study drug to the subject or that could prevent, limit, or confound the protocol specified assessments or study results' interpretation 2. Subjects with a past history of cardiac arrhythmias, risk factors for Torsade de Pointes syndrome (e.g., hypokalemia, family history of long QT Syndrome) or history or clinical evidence at screening of significant or unstable cardiac disease etc. 3. Subjects with a history of clinically significant drug allergy 4. Subject with current or history of clinically significant (as determined by the Investigator) skin disease requiring intermittent or chronic treatment 5. Excessive use of alcohol defined as regular consumption of ≥14 units/week for women and ≥21 units/week for men 6. Subjects with Hepatitis A, C, D, E or HIV-1/HIV-2 infection or acute infections such as SARS- CoV-2 infection 7. Subjects with renal dysfunction (e.g., estimated creatinine clearance \<90 mL/min/1.73 m\^2 at screening, calculated by the Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula) 8. Subject with any history or current evidence of hepatic decompensation such as: variceal bleeding, spontaneous bacterial peritonitis, ascites, hepatic encephalopathy, or active jaundice (within the last year) 9. Subjects must have absence of signs of hepatocellular carcinoma 10. Subjects with history or current liver cirrhosis 11. Subjects positive for anti-HBs antibodies 12. Subjects with liver fibrosis that is classified as Metavir Score ≥F3