A Study to Assess the Safety, Pharmacokinetics, and Antiviral Activity of ABI-4334 in Subjects With Chronic Hepatitis B Virus Infection

A Randomized, Blinded, Placebo-Controlled Dose-Ranging Phase 1b Study of the Safety, Pharmacokinetics, and Antiviral Activity of ABI-4334 in Subjects With Chronic Hepatitis B Virus Infection

This is a randomized, blinded, placebo-controlled, dose-ranging Phase 1b study of the safety, PK, and antiviral activity of ABI-4334 in treatment-naïve or off-treatment chronic Hepatitis B virus (cHBV) subjects that are Hepatitis B e antigen (HBeAg) positive or negative. The study will enroll up to 5 sequential cohorts of 10 subjects each, for a total of up to 50 subjects, randomized 8:2 to receive ABI-4334 or placebo.

Study Overview

• Status: Completed
• Conditions: Chronic Hepatitis B
• Intervention / Treatment: Drug: Placebo; Drug: ABI-4334

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 1

Contacts and Locations

Study Locations

• Moldova, Republic of
  • Chisinau, Moldova, Republic of
    • ARENSIA Exploratory Medicine Chisinau
• New Zealand
  • Auckland, New Zealand
    • New Zealand Clinical Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Body mass index (BMI) ≥ 18.0 and < 35.0 kg/m(2), where BMI = weight (kg)/(height [m])(2) with a minimum body weight of 45 kg
2. Chronic hepatitis B infection, defined as HBV infection for ≥ 6 months documented
3. Treatment-naïve or off-antiviral therapy for ≥ 24 weeks prior to Screening
4. Lack of bridging fibrosis or cirrhosis

Exclusion Criteria:

1. Co-infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis D virus (HDV), acute hepatitis A virus (HAV), or acute hepatitis E virus (HEV)
2. History of liver transplant or evidence of advanced liver disease, cirrhosis, or hepatic decompensation
3. Clinically significant diseases or conditions
4. History of hepatocellular carcinoma

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Drug: Placebo; 10 mg or 50 mg tablets for oral administration
Active Comparator: ABI-4334	Drug: ABI-4334; 10 mg or 50 mg tablets for oral administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the safety and tolerability of ABI-4334 in subjects with cHBV following 28-day multiple oral doses	Proportion of subjects with adverse events (AEs), premature treatment discontinuation due to AEs, and abnormal laboratory results	Through end of study, up to 56 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Elimination half-life (t1/2) of ABI-4334 in subjects with cHBV		Through treatment period, up to 28 days
To characterize the PK of ABI-4334 in plasma following 28-day multiple doses in subjects with cHBV	Noncompartmental plasma PK parameters	Through treatment period, up to 28 days
Changes in HBV DNA in subjects with cHBV following 28-day multiple doses of ABI-4334	Mean change in log10 HBV DNA between Baseline and Day 28	Through treatment period, up to 28 days
To characterize the PK of ABI-4334 in plasma following 28-day multiple doses in subjects with cHBV	Area Under Plasma Concentration-Time Curve (AUC) of ABI-4334 in subjects with cHBV	Through treatment period, up to 28 days
To characterize the PK of ABI-4334 in plasma following 28-day multiple doses in subjects with cHBV	Time to Maximum Plasma Concentration (Tmax) of ABI-4334 in subjects with cHBV	Through treatment period, up to 28 days
Changes in HBV pregenomic ribonucleic acid (pgRNA) and additional markers of antiviral activity in subjects with cHBV	To evaluate the changes in HBV DNA (IU/mL or Log IU/mL) in subjects with cHBV	Through treatment period, up to 28 days
Changes in HBV DNA in subjects with cHBV following 28-day multiple doses of ABI-4334	Proportion of subjects with HBV DNA < lower limit of quantification (LLOQ) and/or limit of detection (LOD)	Through treatment period, up to 28 days
Changes in HBV DNA in subjects with cHBV following 28-day multiple doses of ABI-4334	Mean time elapsed to subjects achieving HBV DNA < LLOQ and/or LOD	Through treatment period, up to 28 days

Collaborators and Investigators

• Sponsor: Assembly Biosciences

Study record dates

Study Major Dates

• Study Start (Actual): June 4, 2024
• Primary Completion (Actual): April 15, 2025
• Study Completion (Actual): May 14, 2025

Study Registration Dates

• First Submitted: April 22, 2024
• First Submitted That Met QC Criteria: April 22, 2024
• First Posted (Actual): April 25, 2024

Study Record Updates

• Last Update Posted (Actual): July 23, 2025
• Last Update Submitted That Met QC Criteria: July 18, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Hepatitis B; cHBV; HBV
• Additional Relevant MeSH Terms: Blood-Borne Infections; Pathologic Processes; Chronic Disease; Disease Attributes; Infections; RNA Virus Infections; Digestive System Diseases; Liver Diseases; Hepatitis, Viral, Human; Enterovirus Infections; Picornaviridae Infections; Communicable Diseases; DNA Virus Infections; Hepadnaviridae Infections; Hepatitis A; Hepatitis; Hepatitis B; Hepatitis B, Chronic; Hepatitis, Chronic; Virus Diseases; Herpesviridae Infections
• Other Study ID Numbers: ABI-4334-102; 2024-511051-18 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No