Study of AHB-171 in Chronic Hepatitis B Participants (EXTEND-101)

A Phase 1 Study in Chronic Hepatitis B Participants to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of AHB-171

The goal of this clinical trial is to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of AHB-171 in participants with chronic hepatitis B (CHB). Study advancement to subsequent parts/cohorts will require satisfactory interim reviews of available cumulative safety data by the Safety Review Committees (SRC), using the safety criteria and review procedures described in the protocol.

Study Overview

• Status: Not yet recruiting
• Conditions: Hepatitis B, Chronic
• Intervention / Treatment: Drug: Nucleos(t)ide Analogue (NA); Drug: AHB-171; Drug: Placebo matching [Investigational Product]

• Study Type: Interventional
• Enrollment (Estimated): 144
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Debbie Liao; Phone Number: (650) 650-2877; Email: ausperbioclinicaltrials@ausperbio.com

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Queen Mary Hospital
• New Zealand
  • Auckland
    • Grafton, Auckland, New Zealand, 1010
      • New Zealand Clinical Research

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male or female participants, aged 18-65 years old (inclusive)
• Body Mass Index between 19 to 35 kg/m2 (inclusive)
• Body weight > or = 45 kg.
• Documented HBV infection for ≥6 months prior to randomization.
• For Parts A and B, on stable approved NA monotherapy for at least 6 months prior to randomization.
• For Part C and D only, not on any NA monotherapy for at least 6 months prior to randomization.
• Screening electrocardiogram (ECG) without clinically significant abnormalities
• Females of childbearing potential must not be breastfeeding, must have a negative serum pregnancy test at Screening, and a negative urine/serum pregnancy test before dosing (unless permanently sterile or >2 years postmenopausal).
• Males and females of childbearing potential must agree to use protocol specified reliable contraception throughout the study.
• Screening HBV DNA, HBsAg and ALT must meet prespecified requirements.

Exclusion Criteria:

• Significant medical conditions other than chronic HBV (e.g. recent heart issues, unstable cardiac disease, uncontrolled diabetes, bleeding disorders, prior organ transplant).
• Other clinically significant liver diseases (e.g. hepatitis from other causes, autoimmune or alcoholic liver disease, prior liver failure).
• History of suspected or confirmed cirrhosis (based on FibroScan® or biopsy).
• Current, past, or suspected liver cancer, or elevated alpha-fetoprotein (AFP) ≥ 20 ng/mL.
• HBV-related extrahepatic diseases (e.g. kidney or vascular conditions).
• Severe infection (other than chronic HBV infection) within 1 month before randomization requiring intravenous treatment.
• Active infections: human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis D virus (HDV) or syphilis (exceptions if RNA negative).
• Abnormal lab results (e.g. low albumin, reduced kidney function, abnormal INR, low platelets, high bilirubin, abnormal blood counts, significant proteinuria).
• History or signs of vasculitis or related autoimmune diseases.
• Malignancy within 5 years (except non-melanoma skin cancer).
• Allergy to study drug components.
• Recent major surgery/trauma (within 3 months) or planned surgery during study.
• Alcohol or substance abuse affecting compliance.
• Pregnancy, breastfeeding, or unwillingness to follow reproductive restrictions.
• Participation in another clinical trial or recent investigational product use.
• Prior treatment with any antisense oligonucleotide or small interfering RNA therapies.
• Recent or ongoing use of immunosuppressive/biologic therapies, certain vaccines, bulevirtide, or unapproved herbal remedies.
• Need for long-term anticoagulants/antiplatelet drugs (unless safely stopped).
• Any other condition making the participant unsuitable (per investigator).

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: AHB-171 or Placebo in CHB (Part A: Single Ascending Dose [SAD])	Drug: Nucleos(t)ide Analogue (NA); Oral administration; Drug: AHB-171; Injection; Drug: Placebo matching [Investigational Product]; Injection
Experimental: AHB-171 or Placebo in CHB (Part B: finite Multiple Dose [MD])	Drug: Nucleos(t)ide Analogue (NA); Oral administration; Drug: AHB-171; Injection; Drug: Placebo matching [Investigational Product]; Injection
Experimental: AHB-171 and placebo in CHB (Part C: finite MD)	Drug: AHB-171; Injection; Drug: Placebo matching [Investigational Product]; Injection
Experimental: AHB-171 and placebo in CHB (Part D: finite MD)	Drug: AHB-171; Injection; Drug: Placebo matching [Investigational Product]; Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Adverse Events (AEs) [Safety and Tolerability]		Up to 72 weeks
The plasma pharmacokinetic (PK) profile of AHB-171 and metabolites: the maximum observed plasma concentration (Cmax) of AHB-171.		Up to 72 weeks
The plasma pharmacokinetic (PK) profile of AHB-171 and metabolites: the area under the concentration-time curve extrapolated to infinity (AUCinf ) of AHB-171		Up to 72 weeks
Incidence of clinically significant changes in Vital Signs [Safety and Tolerability]	Vital signs include body temperature, pulse rate, respiratory rate, and blood pressure	Up to 72 weeks
Incidence of clinically significant changes in cardiac parameters [Safety and Tolerability]	12-lead electrocardiogram (ECG) abnormalities will be reported, with parameters evaluated including PR interval, QRS duration, QT/QTc interval.	Up to 72 weeks
Incidence of laboratory abnormalities [Safety and Tolerability]		Up to 72 weeks
The plasma pharmacokinetic (PK) profile of AHB-171 and metabolites: area under the curve from the time of dosing to the last measurable concentration (AUClast) of AHB-171		Up to 72 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Absolute serum HBsAg (Hepatitis B surface antigen) and change from baseline across all evaluated timepoints in the study		Up to 72 weeks
Absolute serum HBV (Hepatitis B virus) DNA and change from baseline across all evaluated timepoints in the study.		Up to 72 weeks
Absolute serum HBeAb (Hepatitis B e Antibody) and change from baseline across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants achieving pre-specified HBsAg reduction levels or absolute thresholds across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants achieving HBsAg < or ≥ LOD (limit of detection) and/or HBV DNA < or ≥ LLOQ (lower limit of quantitation) across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants achieving pre-specified HBV DNA levels or absolute thresholds across all evaluated timepoints in the study.		Up to 72 weeks
Time to achieving pre-specified HBsAg levels or absolute thresholds across all evaluated timepoints in the study		Up to 72 weeks
Change from baseline in alanine aminotransferase (ALT) levels		Up to 72 weeks
Proportion of participants with ALT normalization among those with elevated ALT at baseline across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants achieving anti-HBs seroconversion across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants experiencing virologic relapse.	Virologic relapse is defined as HBV DNA meeting a protocol-specified threshold value at 2 consecutive visits	Up to 72 weeks
Time to participants experiencing virologic relapse.	Virologic relapse is defined as HBV DNA meeting a protocol-specified threshold value at 2 consecutive visits	Up to 72 weeks
Proportion of participants with treatment emergent AEs (TEAEs), serious AEs (SAEs), or discontinuation due to AEs.		Up to 72 weeks
Proportion of participants with anti-drug antibodies (ADA) to AHB-171.		Up to 72 weeks
ADA titers in participants with ADA to AHB-171 across all evaluated timepoints in the study.		Up to 72 weeks
Plasma PK parameters AUC of AHB-171 and metabolites.		Up to 72 weeks
Plasma PK parameter Cmax of AHB-171 and metabolites.		Up to 72 weeks
Plasma PK parameter Time to Peak Concentration (tmax) of AHB-171 and metabolites.		Up to 72 weeks
Plasma PK parameter apparent clearance (CL [clearance]/F [Bioavailability]) of AHB-171 and metabolites.		Up to 72 weeks
Urine PK parameter cumulative amount excreted (Ae) of AHB-171 and metabolites.		Up to 72 weeks
Urine PK parameter renal clearance (CLr) of AHB-171 and metabolites.		Up to 72 weeks
Absolute serum HBV ribonucleic acid (RNA) and change from baseline across all evaluated timepoints in the study.		Up to 72 weeks
Absolute serum HBcrAg (Hepatitis B core-related antigen) and change from baseline across all evaluated timepoints in the study		Up to 72 weeks
Absolute serum HBeAg (Hepatitis B e antigen) and change from baseline across all evaluated timepoints in the study.		Up to 72 weeks
Proportion of participants with hs-HBsAg (high-sensitivity HBsAg) <LLOQ across all evaluated timepoints in the study.		Up to 72 weeks
Absolute serum HBsAb (Hepatitis B surface Antibody) and change from baseline across all evaluated timepoints in the study.		Time Frame: Up to 72 weeks
Time to first hs-HBsAg <LLOQ, assessed at scheduled visits		Up to 72 weeks

Collaborators and Investigators

• Sponsor: AusperBio Therapeutics Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): July 6, 2026
• Primary Completion (Estimated): October 8, 2027
• Study Completion (Estimated): August 14, 2028

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 24, 2026
• First Posted (Actual): June 1, 2026

Study Record Updates

• Last Update Posted (Actual): June 1, 2026
• Last Update Submitted That Met QC Criteria: May 24, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Blood-Borne Infections; Pathologic Processes; Chronic Disease; Disease Attributes; Infections; Virus Diseases; Digestive System Diseases; Liver Diseases; Hepatitis, Viral, Human; Communicable Diseases; DNA Virus Infections; Hepadnaviridae Infections; Hepatitis, Chronic; Hepatitis; Pathological Conditions, Signs and Symptoms; Hepatitis B; Hepatitis B, Chronic
• Other Study ID Numbers: AB-17-8001

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