Hepatitis B, ChronicPhase 2NCT02065336

A Multicenter Study to Determine the Depth and Duration of Hepatitis B Surface Antigen (HBsAg) Reduction After Single or Multiple Doses of ARC-520, in Combination With Entecavir in Patients With Chronic Hepatitis B Virus (HBV) Infection

A Phase 2 study testing ARC-520, entecavir and chlorpheniramine in people with Hepatitis B, Chronic, run by Arrowhead Pharmaceuticals at 2 sites in Hong Kong.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record

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Trial summary

The purpose of this study is to determine whether ARC-520 in combination with entecavir is effective in the treatment of patients with chronic HBV Infection. Read more about this study

Who is it for?: Ages 18 to 65 years
Conditions the study is for: Hepatitis B, Chronic
What is being tested?: ARC-520, entecavir and chlorpheniramine
Type of treatment: Pill or oral medicine, Injection or infusion
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 58 participants
Where: 2 sitesHong Kong
Study dates: Mar 2014to Jan 2017
Phase: Phase 2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 65 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Diagnosis of HBeAg negative and immune active chronic HBV infection (Cohorts 1-4, 8)
Diagnosis of HBeAg positive and immune active chronic HBV infection (Cohorts 5-6, 9)
Diagnosis of HBeAg negative or HBeAg positive and immune active or tolerant chronic HBV infection (Cohorts 7, 10, 11 \& 12)
Patients with > 6 months of continuous, 0.5 mg/day oral entecavir, and a willingness to continue taking entecavir throughout the study (Cohorts 1-6, 8-9).
Patients naive to entecavir (never on entecavir or on entecavir <30 days prior to screening) and a willingness to take entecavir and willingness to continue taking entecavir throughout the study (Cohorts 7, 11 \& 12).

Who cannot join

Female patients that have a positive pregnancy test or are lactating.
Acute signs of hepatitis/other infection (eg, moderate fever, jaundice, nausea, vomiting, and abdominal pain) evident within 4 weeks of screening and/or at the screening examination.
Patients with antiviral therapy other than entecavir within 3 months of screening or prior treatment with interferon or a toll receptor agonist in the last 5 years.
Use within the last 6 months or an anticipated requirement for anticoagulants, corticosteroids, immunomodulators, or immunosuppressants.
Has any history of autoimmune disease especially autoimmune hepatitis.
Has human immunodeficiency virus (HIV) infection, as shown by the presence of anti-HIV antibody (sero-positive).
Is sero-positive for hepatitis C virus (HCV), and/or a history of delta virus hepatitis.
Has a history of allergy to bee venom or history of hypersensitivity reaction requiring an emergency visit to a physician or hospital and/or requirement for treatment with steroids and/or epinephrine.

Trial locations and contacts

2 sites in 1 country.

Hong Kong2 sites

Research Site 1
Pokfulam
Research Site 2
Shatin

Other trials in Hong Kong

About this study

Official title: A Multicenter, Randomized, Double-blind, Placebo-controlled, Dose-escalation Study to Determine the Depth and Duration of Hepatitis B Surface Antigen (HBsAg) Reduction After a Single Intravenous Dose of ARC-520 in Combination With Entecavir in Patients With Chronic Hepatitis B Virus (HBV) Infection, Followed by a Two-dose Open-label Cohort and Three Open-label Single-dose Cohorts in Treatment Naïve Patients, Including a Multi-dose Open-label Extension at a Single Center

The purpose of this study is to determine whether ARC-520 in combination with entecavir is effective in the treatment of patients with chronic HBV Infection.

Read the detailed description

Treatment with ARC-520 for injection is expected to reduce all HBV proteins and replicative intermediates via ribonucleic acid (RNA) interference. The magnitude of the reduction and duration of effect will depend on the dose. Since to date ARC-520 has not been administered to patients with chronic HBV infection, the effective therapeutic dose in patients with chronic HBV infection is unknown. This study is designed to assess the antiviral activity of ARC-520, especially its effect on HBsAg, in patients with chronic HBV infection at different dose levels.

This is a multicenter, randomized, double-blind, placebo-controlled, single-dose escalation study of ARC 520 in combination with entecavir administered to participants with hepatitis B virus e antigen (HBeAg)-negative (Cohorts 1 through 4) or HBeAg-positive (Cohort 5) immune active, chronic HBV infection, followed by a two-dose open-label cohort (Cohort 6), three open-label single-dose cohorts in treatment-naïve participants (Cohorts 7, 11 and 12) and an open-label multi-dose extension study (Cohorts 8, 9, 10). Cohort 6 will investigate ARC-520 in combination with entecavir administered in two doses to participants with HBeAg-positive immune-active chronic HBV infection. Cohorts 7, 11 and 12 will enroll treatment-naïve participants. Cohort 8 will only enroll participants previously completing Cohorts 1-4. Cohort 9 will only enroll participants previously completing Cohort 5 or 6. Cohort 10 will only enroll participants previously completing Cohort 7.

Participants will undergo the following evaluations at regular intervals during the study: medical history, physical examinations, vital sign measurements (blood pressure, heart rate, respiratory rate, and temperature), weight, adverse events (AEs), 12-lead electrocardiograms (ECGs), concomitant medication, blood sample collection for hematology, coagulation, chemistry, pharmacokinetic (PK) and exploratory pharmacodynamic (PD) measures, urinalysis, HBV serology, HBV genotyping and sequencing, follicle stimulating hormone (FSH) testing and pregnancy testing for females of childbearing potential. Clinically significant changes including AEs will be followed until resolution, until the condition stabilizes, until the event is otherwise explained, or until the participant is lost to follow-up.

Conditions: Hepatitis B, Chronic
Being tested: ARC-520, Placebo, entecavir, chlorpheniramine
Keywords: HBV, Hepatitis
Medical subject headings: Hepatitis B, Chronic, Hepatitis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

ARC-520Drug
PlaceboDrug
entecavirDrug
Also called Baraclude
chlorpheniramineDrug
In all cohorts, each participant received an 8 mg dose of oral chlorpheniramine 2 hours prior to each administration of ARC-520 Injection.

Study groups in NCT02065336
Study group	Role	What they receive
ARC-520 Cohort 1	Experimental	a single intravenous (IV) dose of double-blind ARC-520 Injection 1.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 2	Placebo comparator	a single IV dose of double-blind ARC-520 Injection 2.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 3	Experimental	a single IV dose of double-blind ARC-520 Injection 3.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 4	Experimental	a single IV dose of double-blind ARC-520 Injection 4.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 5	Experimental	a single IV dose of double-blind ARC-520 Injection 4.0 mg/kg in combination with entecavir administered to participants with HBeAg-positive immune active chronic HBV infection Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
Placebo Normal Saline Cohorts 1-5	Experimental	a single IV dose of double-blind normal saline in combination with entecavir administered to participants with HBeAg-negative or -positive immune active chronic HBV infection Receives: Drug: Placebo; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 6	Experimental	two IV doses of open-label ARC-520 2.0 mg/kg administered to participants with HBeAg-positive immune active chronic HBV Receives: Drug: ARC-520; Drug: chlorpheniramine
ARC-520 Cohort 7	Experimental	a single IV dose of open-label ARC-520 4.0 mg/kg administered to treatment-naïve, HBeAg-negative or -positive participants with chronic hepatitis B (CHB) Receives: Drug: ARC-520; Drug: chlorpheniramine
ARC-520 Cohort 8	Experimental	open-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg every [Q]4 weeks) administered to HBeAg-negative participants with CHB receiving chronic entecavir therapy who completed Cohorts 1 through 4 Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 9	Experimental	open-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg Q6 weeks or Q8 weeks) administered to HBeAg-positive participants with CHB receiving chronic entecavir therapy who completed Cohorts 5 or 6 Receives: Drug: ARC-520; Drug: entecavir; Drug: chlorpheniramine
ARC-520 Cohort 10	Experimental	open-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg Q4 weeks) administered to a mixed cohort (HBeAg-negative and -positive participants) who were naïve (within the last 6 months) to entecavir treatment and completed Cohort 7 Receives: Drug: ARC-520; Drug: chlorpheniramine
ARC-520 Cohort 11	Experimental	a single IV dose of open-label ARC-520 5.0 mg/kg administered to treatment-naïve, HBeAg-positive participants with CHB Receives: Drug: ARC-520; Drug: chlorpheniramine
ARC-520 Cohort 12	Experimental	a single IV dose of open-label ARC-520 6.0 mg/kg administered to treatment-naïve, HBeAg-positive participants with CHB Receives: Drug: ARC-520; Drug: chlorpheniramine

What is being measured

The primary outcome is the main question the study is designed to answer.

Change From Baseline Over Time in Quantitative Hepatitis B Surface Antigen (HBsAG)
Measured: Baseline, through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 253 Cohort 10)

Secondary outcomes (12)

Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
An adverse event (AE) is any untoward medical occurrence which does not necessarily have a causal relationship with this treatment. An SAE is any AE that: results in death; is life-threatening; requires inpatient hospitalization or prolongation of an existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; or is a medically important event or reaction.Events were categorized as mild, moderate or severe. TEAEs were defined as all AEs starting or worsening after commencement of treatment with investigational product. A treatment-related TEAE was one whose relationship to treatment was noted as unlikely, possibly, or probably related.
Measured: through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 225 Cohort 10)
Number of Participants With Negative Bee Venom Allergy Test Results at Baseline, Day 29, and Day 85
Bee venom allergy tests were used to assess immunoglobulin E (IgE) in Cohorts 1-7. Analysis values less than 0.35 kU/L were taken as negative.
Measured: Baseline, Day 29, Day 85
Change From Baseline in Entecavir Plasma Trough Concentration, Cohorts 1-7
Measured: Baseline, Days 1, 2, 3, 8, 15, 22, 29
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 to 24 Hours (AUC0-24), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 to the Last Quantifiable Plasma Concentration (AUClast), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 Extrapolated to Infinity (AUCinf), Cohorts 1-5 Only
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Maximum Observed Plasma Concentration (Cmax), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Clearance (CL), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Apparent Volume of Distribution During the Terminal Phase (Vz), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Volume in Steady State (Vss), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Terminal Elimination Rate Constant (Kel), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Terminal Elimination Half-Life (t1/2), Cohorts 1-5
Measured: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Mar 2014Jan 2017

First posted19 Feb 2014 (estimated)
Study startMar 2014
Primary completionJan 2017
Study completionJan 2017

Why it stopped: Company decision to discontinue trial

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Hepatitis B, ChronicStudies of the same condition, open and under way.
More trials run by Arrowhead PharmaceuticalsThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind
Who is masked: Participant, Investigator, Outcomes assessor
Enrolment: 58 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT02065336
Sponsor's protocol ID: Heparc-2001
Status last verified: Dec 2025
First submitted: 13 Feb 2014
Last updated: 13 Jan 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes

Publications

Yuen MF, Wong DK, Schluep T, Lai CL, Ferrari C, Locarnini S, Lo RC, Gish RG, Hamilton J, Wooddell CI, Mak LY, Given BD. Long-term serological, virological and histological responses to RNA inhibition by ARC-520 in Chinese chronic hepatitis B patients on entecavir treatment. Gut. 2022 Apr;71(4):789-797. doi: 10.1136/gutjnl-2020-323445. Epub 2021 Mar 12.
PubMed 33712437

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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Study at a glance

From the registry record, last updated by the sponsor on 13 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Multicenter, Randomized, Double-blind, Placebo-controlled, Dose-escalation Study to Determine the Depth and Duration of Hepatitis B Surface Antigen (HBsAg) Reduction After a Single Intravenous Dose of ARC-520 in Combination With Entecavir in Patients With Chronic Hepatitis B Virus (HBV) Infection, Followed by a Two-dose Open-label Cohort and Three Open-label Single-dose Cohorts in Treatment Naïve Patients, Including a Multi-dose Open-label Extension at a Single Center
ClinicalTrials.gov ID: NCT02065336
Acronym / sponsor ID: Heparc-2001
Conditions: Hepatitis B, Chronic
Keywords: HBV, Hepatitis
Phase: Phase 2
Study type: Interventional
Recruitment status: TerminatedReason stopped: Company decision to discontinue trial
Enrolment: 58 participants (actual)
Lead sponsor: Arrowhead PharmaceuticalsIndustry (pharma, biotech, devices)
Collaborators: ICON Clinical Research
Study start: Mar 2014 (actual)
Primary completion: Jan 2017 (actual)
Study completion: Jan 2017 (actual)
First posted: 19 Feb 2014 (estimated)
Results: Posted 5 Jul 2019

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

The purpose of this study is to determine whether ARC-520 in combination with entecavir is effective in the treatment of patients with chronic HBV Infection.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind (participant, investigator, outcomes assessor)
Number of arms: 13

Arm	Type	Receives
ARC-520 Cohort 1	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniraminea single intravenous (IV) dose of double-blind ARC-520 Injection 1.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection
ARC-520 Cohort 2	Placebo comparator	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniraminea single IV dose of double-blind ARC-520 Injection 2.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection
ARC-520 Cohort 3	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniraminea single IV dose of double-blind ARC-520 Injection 3.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection
ARC-520 Cohort 4	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniraminea single IV dose of double-blind ARC-520 Injection 4.0 mg/kg in combination with entecavir administered to participants with HBeAg-negative immune active chronic HBV infection
ARC-520 Cohort 5	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniraminea single IV dose of double-blind ARC-520 Injection 4.0 mg/kg in combination with entecavir administered to participants with HBeAg-positive immune active chronic HBV infection
Placebo Normal Saline Cohorts 1-5	Experimental	Drug: Placebo, Drug: entecavir, Drug: chlorpheniraminea single IV dose of double-blind normal saline in combination with entecavir administered to participants with HBeAg-negative or -positive immune active chronic HBV infection
ARC-520 Cohort 6	Experimental	Drug: ARC-520, Drug: chlorpheniraminetwo IV doses of open-label ARC-520 2.0 mg/kg administered to participants with HBeAg-positive immune active chronic HBV
ARC-520 Cohort 7	Experimental	Drug: ARC-520, Drug: chlorpheniraminea single IV dose of open-label ARC-520 4.0 mg/kg administered to treatment-naïve, HBeAg-negative or -positive participants with chronic hepatitis B (CHB)
ARC-520 Cohort 8	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniramineopen-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg every [Q]4 weeks) administered to HBeAg-negative participants with CHB receiving chronic entecavir therapy who completed Cohorts 1 through 4
ARC-520 Cohort 9	Experimental	Drug: ARC-520, Drug: entecavir, Drug: chlorpheniramineopen-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg Q6 weeks or Q8 weeks) administered to HBeAg-positive participants with CHB receiving chronic entecavir therapy who completed Cohorts 5 or 6
ARC-520 Cohort 10	Experimental	Drug: ARC-520, Drug: chlorpheniramineopen-label multi-dose extension cohort: multiple IV doses of open-label ARC-520 (4.0 mg/kg Q4 weeks) administered to a mixed cohort (HBeAg-negative and -positive participants) who were naïve (within the last 6 months) to entecavir treatment and completed Cohort 7
ARC-520 Cohort 11	Experimental	Drug: ARC-520, Drug: chlorpheniraminea single IV dose of open-label ARC-520 5.0 mg/kg administered to treatment-naïve, HBeAg-positive participants with CHB
ARC-520 Cohort 12	Experimental	Drug: ARC-520, Drug: chlorpheniraminea single IV dose of open-label ARC-520 6.0 mg/kg administered to treatment-naïve, HBeAg-positive participants with CHB

Who may qualify

Ages: 18 to 65 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (5 listed)

Diagnosis of HBeAg negative and immune active chronic HBV infection (Cohorts 1-4, 8)
Diagnosis of HBeAg positive and immune active chronic HBV infection (Cohorts 5-6, 9)
Diagnosis of HBeAg negative or HBeAg positive and immune active or tolerant chronic HBV infection (Cohorts 7, 10, 11 \& 12)
Patients with > 6 months of continuous, 0.5 mg/day oral entecavir, and a willingness to continue taking entecavir throughout the study (Cohorts 1-6, 8-9).
Patients naive to entecavir (never on entecavir or on entecavir <30 days prior to screening) and a willingness to take entecavir and willingness to continue taking entecavir throughout the study (Cohorts 7, 11 \& 12).

Key exclusion criteria (8 listed)

Female patients that have a positive pregnancy test or are lactating.
Acute signs of hepatitis/other infection (eg, moderate fever, jaundice, nausea, vomiting, and abdominal pain) evident within 4 weeks of screening and/or at the screening examination.
Patients with antiviral therapy other than entecavir within 3 months of screening or prior treatment with interferon or a toll receptor agonist in the last 5 years.
Use within the last 6 months or an anticipated requirement for anticoagulants, corticosteroids, immunomodulators, or immunosuppressants.
Has any history of autoimmune disease especially autoimmune hepatitis.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
ARC-520	Drug	ARC-520 Cohort 1, ARC-520 Cohort 10, ARC-520 Cohort 11, ARC-520 Cohort 12, ARC-520 Cohort 2, ARC-520 Cohort 3, ARC-520 Cohort 4, ARC-520 Cohort 5, ARC-520 Cohort 6, ARC-520 Cohort 7, ARC-520 Cohort 8, ARC-520 Cohort 9
Placebo	Drug	Placebo Normal Saline Cohorts 1-5
entecavirAlso: Baraclude	Drug	ARC-520 Cohort 1, ARC-520 Cohort 2, ARC-520 Cohort 3, ARC-520 Cohort 4, ARC-520 Cohort 5, ARC-520 Cohort 8, ARC-520 Cohort 9, Placebo Normal Saline Cohorts 1-5
chlorpheniramineIn all cohorts, each participant received an 8 mg dose of oral chlorpheniramine 2 hours prior to each administration of ARC-520 Injection.	Drug	ARC-520 Cohort 1, ARC-520 Cohort 10, ARC-520 Cohort 11, ARC-520 Cohort 12, ARC-520 Cohort 2, ARC-520 Cohort 3, ARC-520 Cohort 4, ARC-520 Cohort 5, ARC-520 Cohort 6, ARC-520 Cohort 7, ARC-520 Cohort 8, ARC-520 Cohort 9, Placebo Normal Saline Cohorts 1-5

Primary outcome

Change From Baseline Over Time in Quantitative Hepatitis B Surface Antigen (HBsAG)
Time frame: Baseline, through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 253 Cohort 10)

12 secondary outcomes

Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame: through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 225 Cohort 10)
Number of Participants With Negative Bee Venom Allergy Test Results at Baseline, Day 29, and Day 85
Time frame: Baseline, Day 29, Day 85
Change From Baseline in Entecavir Plasma Trough Concentration, Cohorts 1-7
Time frame: Baseline, Days 1, 2, 3, 8, 15, 22, 29
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 to 24 Hours (AUC0-24), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 to the Last Quantifiable Plasma Concentration (AUClast), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Area Under the Plasma Concentration-Time Curve From Time 0 Extrapolated to Infinity (AUCinf), Cohorts 1-5 Only
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Maximum Observed Plasma Concentration (Cmax), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Clearance (CL), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Apparent Volume of Distribution During the Terminal Phase (Vz), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Volume in Steady State (Vss), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Terminal Elimination Rate Constant (Kel), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose
Pharmacokinetics of ARC-520 Product Constituents AD0009 and AD0010: Terminal Elimination Half-Life (t1/2), Cohorts 1-5
Time frame: Day 1 predose, immediately prior to the end of infusion, 0.5, 1, 3, 6, 24, and 48 hours postdose

Results and safety

Results posted to the registry on 5 Jul 2019, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
ARC-520 Cohort 1	6	6
ARC-520 Cohort 2	6	6
ARC-520 Cohort 3	6	6
ARC-520 Cohort 4	6	6
ARC-520 Cohort 5	6	6
ARC-520 Cohort 6	6	6
ARC-520 Cohort 7	12	12
Placebo Normal Saline Cohorts 1-5	10	10
ARC-520 Cohort 9	0	0
ARC-520 Cohort 10	0	0

Primary outcome: Change From Baseline Over Time in Quantitative Hepatitis B Surface Antigen (HBsAG)

Time frame: Baseline, through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 253 Cohort 10). Mean (Standard Deviation). Unit: IU/mL

Measure	ARC-520 Cohort 1 n = 6	ARC-520 Cohort 2 n = 6	ARC-520 Cohort 3 n = 6	ARC-520 Cohort 4 n = 6	ARC-520 Cohort 5 n = 6	ARC-520 Cohort 6 n = 6	ARC-520 Cohort 7 n = 12	Placebo Normal Saline Cohorts 1-5 n = 10	ARC-520 Cohort 9 n = 0	ARC-520 Cohort 10 n = 8
Day 1	–	–	–	–	–	–	–	–	–	-19222 (27217)
Day 3	-554.8 (861.86)	-1194.0 (2083.72)	-1003.6 (949.36)	-1501.0 (1930.12)	-1664.7 (2375.62)	-948.0 (1016.31)	-12401.1 (17661.02)	43.3 (267.60)	–	–
Day 8	-928.1 (1285.26)	-2179.2 (3170.68)	-884.3 (1296.49)	-2591.2 (3304.72)	-1789.8 (2101.23)	-1344.0 (1319.66)	-20123.8 (29795.99)	42.2 (568.32)	–	–
Day 15	-1055.1 (1900.89)	-2260.8 (4022.82)	-470.8 (2025.31)	-3069.0 (3923.45)	-1672.8 (1892.73)	–	-22915.6 (34381.59)	236.6 (321.17)	–	–
Day 22	-1225.4 (1967.15)	-2266.2 (3868.90)	-204.3 (2077.12)	-2978.8 (3536.73)	-1951.7 (2819.85)	-1553.7 (1596.05)	-23872.7 (35753.39)	115.1 (594.38)	–	–
Day 29	-579.1 (352.71)	-1826.3 (2618.78)	93.3 (2425.68)	-2972.8 (3506.01)	-1964.3 (2501.62)	-1532.3 (1500.40)	-24148.3 (36256.02)	168.8 (460.59)	–	-22617 (32653)
Day 43	-1020.1 (1252.98)	-1288.8 (1498.60)	-1471.8 (1625.30)	-3219.8 (3601.70)	-1939.7 (2277.79)	-1566.8 (1290.46)	-23932.0 (35929.80)	58.3 (411.60)	–	–
Day 57	–	-1056.7 (773.69)	-2330.1 (1676.50)	-2813.0 (2665.97)	-1536.0 (1373.46)	-1370.7 (872.64)	-22658.4 (34292.84)	156.1 (527.40)	–	-22840 (32239)

Population analysed: Pharmacodynamic (PD) Population: all participants who received at least 1 dose of study drug and had evaluable data from at least one postdose PD assessment according to the treatment the participants were assigned.

12 secondary outcomes are reported in the full results.

Adverse events

Time frame: From first dose of study drug through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 225 Cohort 10). Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
ARC-520 Cohort 1	0 of 6 (0%)	1 of 6 (16.7%)	Not reported
ARC-520 Cohort 2	0 of 6 (0%)	4 of 6 (66.7%)	Not reported
ARC-520 Cohort 3	0 of 6 (0%)	1 of 6 (16.7%)	Not reported
ARC-520 Cohort 4	0 of 6 (0%)	0 of 6 (0%)	Not reported
ARC-520 Cohort 5	0 of 6 (0%)	1 of 6 (16.7%)	Not reported
ARC-520 Cohort 6	0 of 6 (0%)	1 of 6 (16.7%)	Not reported
ARC-520 Cohort 7	0 of 12 (0%)	1 of 12 (8.3%)	Not reported
ARC-520 Cohort 9	0 of 2 (0%)	1 of 2 (50%)	Not reported
ARC-520 Cohort 10	0 of 8 (0%)	7 of 8 (87.5%)	Not reported
Placebo Normal Saline Cohorts 1-5	0 of 10 (0%)	0 of 10 (0%)	Not reported

Limitations and caveats (from the sponsor): The ARC-520 Injection development program was terminated early for regulatory and business reasons secondary to findings occurring in a non-clinical toxicology study. Program termination was not due to safety findings in humans.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 13 Jan 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 33712437Yuen MF, Wong DK, Schluep T, Lai CL, Ferrari C, Locarnini S, Lo RC, Gish RG, Hamilton J, Wooddell CI, Mak LY, Given BD. Long-term serological, virological and histological responses to RNA inhibition by ARC-520 in Chinese chronic hepatitis B patients on entecavir treatment. Gut. 2022 Apr;71(4):789-797. doi: 10.1136/gutjnl-2020-323445. Epub 2021 Mar 12.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Bruce Given, MD study chair

Arrowhead Pharmaceuticals, Inc.

2 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing ARC-520, entecavir and chlorpheniramine in people with Hepatitis B, Chronic, run by Arrowhead Pharmaceuticals at 2 sites in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 13 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 5 Jul 2019). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change From Baseline Over Time in Quantitative Hepatitis B Surface Antigen (HBsAG) (time frame: Baseline, through Day 85 (Cohorts 1-7) and through 24 weeks post-last dose (last dose: Day 85 Cohort 9; Day 253 Cohort 10)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02065336, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jan 2026.