Study of Oral TLR8 Agonist Selgantolimod on HBsAg in Participants With Both Chronic Hepatitis B and HIV

Inclusion Criteria: 1. HIV-1 infection 2. Effective antiviral therapy for HIV (ART) and HBV that includes TDF, TAF, TDF/FTC, TDF/3TC (tenofovir disoproxil fumarate plus lamivudine), TAF/FTC, or entecavir (ETV), for ≥5 years immediately prior to study entry. ART is defined as including a minimum of two anti-HIV antivirals. 3. CD4+ cell count ≥350 cells/mm3 4. HIV-1 RNA \<50 copies/mL measured on at least two occasions at least 12 weeks apart, with no documented value \>200 copies/mL, over the 12 months prior to study entry. 5. Positive or negative HBeAg 6. Negative anti-HDV 7. Current CHB infection 8. HBV DNA level \<50 IU/mL measured on at least two occasions at least 12 weeks apart, with no documented value ≥50 IU/mL, over the 12 months prior to study entry. 9. Quantitative HBsAg \>1000 IU/mL 10. Hepatitis C virus (HCV) antibody negative, or if the participant is HCV antibody positive, an undetectable HCV RNA. 11. Participants age ≥18 years and ≤70 years at study entry 12. Participants must agree to stay on an effective antiviral therapy for HIV (ART) and HBV throughout the study. Exclusion Criteria: 1. Receipt of treatment for HCV within 24 weeks prior to study entry 2. Evidence of advanced fibrosis or cirrhosis (Metavir ≥F3 or equivalent). 3. Current or prior history of clinical hepatic decompensation (e.g., ascites, encephalopathy, or variceal hemorrhage) 4. History of HCC or cholangiocarcinoma 5. Malignancy within 5 years prior to study entry. NOTE: A history of non-melanoma skin cancer (e.g., basal cell carcinoma or squamous cell skin cancer) is not exclusionary. 6. History of solid organ transplantation 7. Presence of any active or acute AIDS-defining opportunistic infections within 60 days prior to study entry 8. History of uveitis or posterior synechiae 9. Breastfeeding