A Randomized, Double-Blind, Placebo-Controlled, Phase 1 Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of GIGA-2339 Administered as a Single Ascending Dose and Multiple Ascending Doses in Participants With Chronic Hepatitis B Virus Infection

Key Inclusion Criteria: * Hepatitis B envelope antigen (HBeAg) negative chronic HBV infection for ≥ 6 months, defined as presence of Hepatitis B surface antigen (HBsAg) in serum for ≥ 6 months. * Serum HBsAg concentration between ≥ 100 international units per milliliter (IU/mL) and 2000 IU/mL at screening. * Currently on stable dose of nucleot(s)ide analogues (NAs) (≥ 6 months) and expected to continue while participating in the study, or are not received NAs. * Have serum HBV deoxyribonucleic acid (DNA) concentration ≤ 50 IU/mL at screening (for those who are on NAs); or have serum HBV DNA c…