Hepatitis BPhase 1NCT02797522
A Study of ARC-521 Injection in Normal Adult Volunteers and Patients With Chronic Hepatitis B (CHB)
A Phase 1 study testing ARC-521 Injection, antihistamine and acetaminophen in people with Hepatitis B, run by Arrowhead Pharmaceuticals at 1 site in New Zealand.
Trial summary
Normal healthy volunteer (NHV) participants will enroll sequentially into a total of 6 escalating dose levels (6 subjects per dose level), randomized to receive a single dose of ARC-521 Injection or placebo. The maximum study duration for NHVs is approximately 21 weeks. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Hepatitis B
- What is being tested?
- ARC-521 Injection, antihistamine and acetaminophen
- 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
- 47 participants
- Where
- 1 siteNew Zealand
- Study dates
- Jun 2016to Nov 2016
- Phase
- Phase 1
- 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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male or female, 18 to 55 years of age inclusive (NHVs) or 18-65 years of age inclusive (CHBs), at the time of informed consent
- Able to provide written informed consent prior to the performance of any study specific procedures
- Body mass index (BMI) between 19.0 and 35.0 kg/m2, inclusive
- A 12-lead ECG at Screening and pre-dose assessment that, in the opinion of the investigator, has no abnormalities that compromise participant's safety in this study
- Must use 2 effective methods of contraception (double barrier contraception or hormonal contraceptive along with a barrier contraceptive (both male and female partners)
- Have suitable venous access for blood sampling
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- No abnormal finding of clinical relevance at the Screening evaluation (NHVs only)
- Have a diagnosis of HbeAg-negative chronic HBV infection (CHB patients only)
- Treatment-naive or currently on entecavir/tenofovir for 6 months or longer
Who cannot join
- Pregnant or lactating
- Acute signs of hepatitis/other infection at Screening or at baseline
- Use within last 14 days or anticipated requirement for anticoagulants, systemic corticosteroids, immunomodulators, or immunosuppressants
- Use of prescription medication within 14 days prior to study treatment that in the opinion of the PI or the Sponsor would interfere with study conduct.
- Known diagnosis of non-alcoholic steatohepatitis [NHVs only] or familial hypercholesterolemia
- Taking interferon alpha (INFalpha) within 6 months of screening [CHBs only]
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- History of poorly controlled autoimmune disease or history of autoimmune hepatitis
- Human immunodeficiency virus (HIV) infection
- Seropositive for HBV (NHVs only) or hepatitis C virus (HCV), and/or history of delta virus hepatitis
- Hypertension defined as blood pressure > 170/100 mmHg at screening [NHVs only]
- A history of cardiac rhythm disturbances
- Family history of congenital long QT syndrome, Brugada syndrome or unexplained sudden cardiac death
- Symptomatic heart failure, unstable angina, myocardial infarction, severe cardiovascular disease within 6 months prior to study entry
- History of malignancy within the last 5 years except for adequately treated basal cell carcinoma, squamous cell skin cancer, superficial bladder tumors, or in situ cervical cancer
- History of major surgery within 3 months of Screening
- Regular use of alcohol within one month prior to the Screening visit (more than fourteen units of alcohol per week)
- Evidence of severe systemic acute inflammation, sepsis, or hemolysis [NHVs only]
- Use within 3 months of illicit drugs (cocaine, phencyclidine [PCP], 3,4-methylenedioxymethamphetamine [MDMA], others) or positive test for drugs of abuse at screening.
- History of allergy to bee venom or history of severe hypersensitivity reaction, such as anaphylaxis
- Use of an investigational agent or device within 30 days prior to dosing or current participation in an investigational study
- Clinically significant history of any alcoholic liver disease, cirrhosis, Wilson's disease, hemochromatosis, or alpha-1 antitrypsin deficiency, liver or kidney disease
- Clinically significant history/presence of poorly controlled or decompensated neurological, endocrine, cardiovascular, pulmonary, hematological, immunologic, psychiatric, metabolic, or other uncontrolled systemic disease
- Blood donation (500 mL) within 7 days prior to study treatment administration [NHVs only]
- History of fever (>38.0ºC/100.4ºF) within 2 weeks of Screening [NHVs only]
- Any concomitant medical or psychiatric condition or social situation that impacts compliance or involves additional safety risk
- History of coagulopathy (including deep vein thrombosis and pulmonary embolism) or stroke within 6 months of baseline, and/or concurrent anticoagulant medication(s)
- Presence of cholangitis, cholecystitis, cholestasis, or duct obstruction
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Sequential Phase 1a/1b Dose-Escalating Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Antiviral Activity of ARC-521 in Normal Adult Volunteers and Patients With Chronic Hepatitis B
Normal healthy volunteer (NHV) participants will enroll sequentially into a total of 6 escalating dose levels (6 subjects per dose level), randomized to receive a single dose of ARC-521 Injection or placebo. The maximum study duration for NHVs is approximately 21 weeks.
Hepatitis B e Antigen (HBeAg)-negative participants with (CHB) will enroll sequentially into 3 dose levels (8 patients per dose level) to receive multiple doses of open label ARC-521 Injection. For each CHB participant the maximum study duration is approximately 37 weeks.
Read the detailed description
Phase 1a/1b multicenter dose-escalation study of ARC-521 Injection in normal healthy volunteers and patients with CHB. Eligible participants who have signed an Ethics Committee (EC)/Institutional Review Board (IRB) approved informed consent form and have met all of the protocol eligibility criteria.
Patients 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 assessment (AEs), concomitant medications/therapies assessment, electrocardiograms (ECGs), telemetry [NHVs only], measures of hepatic fibrosis [CHBs only], blood sample collection for hematology, coagulation, chemistry, Pharmacokinetics (PK) [NHVs only], metabolic analysis [NHVs only], exploratory Pharmacodynamic (PD) measures, urinalysis, hepatitis B virus (HBV) serology, immunogenicity, Follicle Stimulating Hormone (FSH) testing (post-menopausal females) 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 patient is lost to follow-up. Prior to enrollment there is a 60 day screening period.
- Conditions
- Hepatitis B
- Being tested
- ARC-521 Injection, Placebo, antihistamine, acetaminophen, entecavir
- Medical subject headings
- Hepatitis B
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ARC-521 InjectionDrug
PlaceboOther
0.9% normal saline
antihistamineDrug
Approximately two hours prior to ARC-521 or placebo administration, participants will be pre-treated with an oral antihistamine, selected by the investigator from the list of approved antihistamines that is available in that country. Approved antihistamines are: diphenhydramine 50 mg by mouth (PO), chlorpheniramine 8 mg PO, or hydroxyzine 50 mg PO.
acetaminophenDrug
Approximately two hours prior to ARC-521 or placebo administration, participants will be pre-treated with acetaminophen (500 - 1000 mg PO, per local strength availability).
entecavirDrug
Participants take entecavir OR tenofovir daily throughout the study.
tenofovirDrug
Participants take entecavir OR tenofovir daily throughout the study.
| Study group | Role | What they receive |
|---|---|---|
| NHV Participants: Cohort 1 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 0.6 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Cohort 2 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 1 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Cohort 3 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 2 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Cohort 4 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 4 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Cohort 5 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 5 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Cohort 6 | Experimental | NHV participants administered a single dose of ARC-521 Injection at a dose of 6 mg/kg. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| NHV Participants: Placebo | Placebo comparator | NHV participants administered 0.9% normal saline to match ARC-521 Injection at doses of 0.6, 1, 2, 4, 5 and 6 mg/kg. Receives: Other: Placebo; Drug: antihistamine; Drug: acetaminophen |
| CHB Participants: Cohort 3b | Experimental | Treatment-naive participants with CHB administered 3 doses of ARC-521 Injection at 2 mg/kg once every 4 weeks. Participants are treatment-naive if they have not been on continual nucleoside analog (NUC) therapy (any NUC) for at least 6 months prior to screening (or have never been on NUCs). Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| CHB Participants: Cohort 4b | Experimental | Treatment-naive participants with CHB administered 3 doses of ARC-521 Injection at 4 mg/kg once every 4 weeks. Participants are treatment-naive if they have not been on continual NUC therapy (any NUC) for at least 6 months prior to screening (or have never been on NUCs). Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen |
| CHB Participants: Cohort 3c | Experimental | Participants with CHB currently on NUCs (entecavir or tenofovir for at least 6 months) administered 3 doses of ARC-521 Injection at 2 mg/kg once every 4 weeks. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen; Drug: entecavir; Drug: tenofovir |
| CHB Participants: Cohort 4c | Experimental | Participants with CHB currently on NUCs (entecavir or tenofovir for at least 6 months) administered 3 doses of ARC-521 Injection at 4 mg/kg once every 4 weeks. Receives: Drug: ARC-521 Injection; Drug: antihistamine; Drug: acetaminophen; Drug: entecavir; Drug: tenofovir |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Treatment-Emergent Adverse Events (TEAEs): Healthy Volunteers
An adverse event (AE) is any untoward medical occurrence which does not necessarily have a causal relationship with this treatment. A serious AE 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: From first dose of study drug through Day 29 (± 1 day)
Number of Participants With TEAEs: CHB Participants
An AE is any untoward medical occurrence which does not necessarily have a causal relationship with this treatment. A serious AE 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: From first dose of study drug through Day 142 (± 3 days)
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0-24 Hours (AUC0-24), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0 to the Last Quantifiable Plasma Concentration (AUClast), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0 Extrapolated to Infinity (AUCinf), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Maximum Observed Plasma Concentration (Cmax), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Clearance (CL), Healthy Volunteers
Measured: Through 48 hrs post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Apparent Volume of Distribution (V), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Terminal Elimination Rate Constant (Kel), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Terminal Elimination Half-Life (t1/2), Healthy Volunteers
Measured: Through 48 hours post-dose on Day 1
Change Over Time in Viral Antigens and DNA in CHB Participants as a Measure of Activity of ARC-521 Injection
Measured: Baseline to Day 142
Secondary outcomes (2)
Change Over Time in Cytokine Levels After Single and Multiple Doses of ARC-521 Injection
Measured: Through 24 hours post-dose (Day 1 for NHVs, and Days 1, 29 & 57 for CHB participants)
Change Over Time in Complement Levels After Single and Multiple Doses of ARC-521 Injection
Measured: Through 24 hours post-dose (Day 1 for NHVs, and Days 1, 29 & 57 for CHB participants)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jun 2016 (estimated)
- Study startJun 2016
- Primary completionNov 2016
- Study completionNov 2016
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.
- Other trials for Hepatitis BStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 47 participants (actual)
Sponsor and investigators
- Lead sponsor
- Arrowhead Pharmaceuticals
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02797522
- Sponsor's protocol ID
- ARC5211001
- Status last verified
- Dec 2025
- First submitted
- 8 Jun 2016
- Last updated
- 12 Jan 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Sequential Phase 1a/1b Dose-Escalating Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Antiviral Activity of ARC-521 in Normal Adult Volunteers and Patients With Chronic Hepatitis B
- ClinicalTrials.gov ID
- NCT02797522
- Acronym / sponsor ID
- ARC5211001
- Conditions
- Hepatitis B
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Company decision to discontinue trial
- Enrolment
- 47 participants (actual)
- Lead sponsor
- Arrowhead PharmaceuticalsIndustry (pharma, biotech, devices)
- Study start
- Jun 2016 (actual)
- Primary completion
- Nov 2016 (actual)
- Study completion
- Nov 2016 (actual)
- First posted
- 13 Jun 2016 (estimated)
- Results
- Posted 25 Sep 2018
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Normal healthy volunteer (NHV) participants will enroll sequentially into a total of 6 escalating dose levels (6 subjects per dose level), randomized to receive a single dose of ARC-521 Injection or placebo. The maximum study duration for NHVs is approximately 21 weeks.
Hepatitis B e Antigen (HBeAg)-negative participants with (CHB) will enroll sequentially into 3 dose levels (8 patients per dose level) to receive multiple doses of open label ARC-521 Injection. For each CHB participant the maximum study duration is approximately 37 weeks.
Detailed description
Phase 1a/1b multicenter dose-escalation study of ARC-521 Injection in normal healthy volunteers and patients with CHB. Eligible participants who have signed an Ethics Committee (EC)/Institutional Review Board (IRB) approved informed consent form and have met all of the protocol eligibility criteria.
Patients 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 assessment (AEs), concomitant medications/therapies assessment, electrocardiograms (ECGs), telemetry [NHVs only], measures of hepatic fibrosis [CHBs only], blood sample collection for hematology, coagulation, chemistry, Pharmacokinetics (PK) [NHVs only], metabolic analysis [NHVs only], exploratory Pharmacodynamic (PD) measures, urinalysis, hepatitis B virus (HBV) serology, immunogenicity, Follicle Stimulating Hormone (FSH) testing (post-menopausal females) 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 patient is lost to follow-up. Prior to enrollment there is a 60 day screening period.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 11
| Arm | Type | Receives |
|---|---|---|
| NHV Participants: Cohort 1 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 0.6 mg/kg. |
| NHV Participants: Cohort 2 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 1 mg/kg. |
| NHV Participants: Cohort 3 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 2 mg/kg. |
| NHV Participants: Cohort 4 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 4 mg/kg. |
| NHV Participants: Cohort 5 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 5 mg/kg. |
| NHV Participants: Cohort 6 | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenNHV participants administered a single dose of ARC-521 Injection at a dose of 6 mg/kg. |
| NHV Participants: Placebo | Placebo comparator | Other: Placebo, Drug: antihistamine, Drug: acetaminophenNHV participants administered 0.9% normal saline to match ARC-521 Injection at doses of 0.6, 1, 2, 4, 5 and 6 mg/kg. |
| CHB Participants: Cohort 3b | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenTreatment-naive participants with CHB administered 3 doses of ARC-521 Injection at 2 mg/kg once every 4 weeks. Participants are treatment-naive if they have not been on continual nucleoside analog (NUC) therapy (any NUC) for at least 6 months prior to screening (or have never been on NUCs). |
| CHB Participants: Cohort 4b | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophenTreatment-naive participants with CHB administered 3 doses of ARC-521 Injection at 4 mg/kg once every 4 weeks. Participants are treatment-naive if they have not been on continual NUC therapy (any NUC) for at least 6 months prior to screening (or have never been on NUCs). |
| CHB Participants: Cohort 3c | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophen, Drug: entecavir, Drug: tenofovirParticipants with CHB currently on NUCs (entecavir or tenofovir for at least 6 months) administered 3 doses of ARC-521 Injection at 2 mg/kg once every 4 weeks. |
| CHB Participants: Cohort 4c | Experimental | Drug: ARC-521 Injection, Drug: antihistamine, Drug: acetaminophen, Drug: entecavir, Drug: tenofovirParticipants with CHB currently on NUCs (entecavir or tenofovir for at least 6 months) administered 3 doses of ARC-521 Injection at 4 mg/kg once every 4 weeks. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Male or female, 18 to 55 years of age inclusive (NHVs) or 18-65 years of age inclusive (CHBs), at the time of informed consent
- Able to provide written informed consent prior to the performance of any study specific procedures
- Body mass index (BMI) between 19.0 and 35.0 kg/m2, inclusive
- A 12-lead ECG at Screening and pre-dose assessment that, in the opinion of the investigator, has no abnormalities that compromise participant's safety in this study
- Must use 2 effective methods of contraception (double barrier contraception or hormonal contraceptive along with a barrier contraceptive (both male and female partners)
Key exclusion criteria (27 listed)
- Pregnant or lactating
- Acute signs of hepatitis/other infection at Screening or at baseline
- Use within last 14 days or anticipated requirement for anticoagulants, systemic corticosteroids, immunomodulators, or immunosuppressants
- Use of prescription medication within 14 days prior to study treatment that in the opinion of the PI or the Sponsor would interfere with study conduct.
- Known diagnosis of non-alcoholic steatohepatitis [NHVs only] or familial hypercholesterolemia
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-521 Injection | Drug | CHB Participants: Cohort 3b, CHB Participants: Cohort 3c, CHB Participants: Cohort 4b, CHB Participants: Cohort 4c, NHV Participants: Cohort 1, NHV Participants: Cohort 2, NHV Participants: Cohort 3, NHV Participants: Cohort 4, NHV Participants: Cohort 5, NHV Participants: Cohort 6 |
| Placebo0.9% normal saline | Other | NHV Participants: Placebo |
| antihistamineApproximately two hours prior to ARC-521 or placebo administration, participants will be pre-treated with an oral antihistamine, selected by the investigator from the list of approved antihistamines that is available in that country. Approved antihistamines are: diphenhydramine 50 mg by mouth (PO), chlorpheniramine 8 mg PO, or hydroxyzine 50 mg PO. | Drug | CHB Participants: Cohort 3b, CHB Participants: Cohort 3c, CHB Participants: Cohort 4b, CHB Participants: Cohort 4c, NHV Participants: Cohort 1, NHV Participants: Cohort 2, NHV Participants: Cohort 3, NHV Participants: Cohort 4, NHV Participants: Cohort 5, NHV Participants: Cohort 6, NHV Participants: Placebo |
| acetaminophenApproximately two hours prior to ARC-521 or placebo administration, participants will be pre-treated with acetaminophen (500 - 1000 mg PO, per local strength availability). | Drug | CHB Participants: Cohort 3b, CHB Participants: Cohort 3c, CHB Participants: Cohort 4b, CHB Participants: Cohort 4c, NHV Participants: Cohort 1, NHV Participants: Cohort 2, NHV Participants: Cohort 3, NHV Participants: Cohort 4, NHV Participants: Cohort 5, NHV Participants: Cohort 6, NHV Participants: Placebo |
| entecavirParticipants take entecavir OR tenofovir daily throughout the study. | Drug | CHB Participants: Cohort 3c, CHB Participants: Cohort 4c |
| tenofovirParticipants take entecavir OR tenofovir daily throughout the study. | Drug | CHB Participants: Cohort 3c, CHB Participants: Cohort 4c |
Primary outcome
Number of Participants With Treatment-Emergent Adverse Events (TEAEs): Healthy Volunteers
Time frame: From first dose of study drug through Day 29 (± 1 day)
An adverse event (AE) is any untoward medical occurrence which does not necessarily have a causal relationship with this treatment. A serious AE 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.
Number of Participants With TEAEs: CHB Participants
Time frame: From first dose of study drug through Day 142 (± 3 days)
An AE is any untoward medical occurrence which does not necessarily have a causal relationship with this treatment. A serious AE 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.
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0-24 Hours (AUC0-24), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0 to the Last Quantifiable Plasma Concentration (AUClast), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Area Under the Plasma-Concentration-Time Curve From Time 0 Extrapolated to Infinity (AUCinf), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Maximum Observed Plasma Concentration (Cmax), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Clearance (CL), Healthy Volunteers
Time frame: Through 48 hrs post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Apparent Volume of Distribution (V), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Terminal Elimination Rate Constant (Kel), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Pharmacokinetics of ARC-521 Injection: Terminal Elimination Half-Life (t1/2), Healthy Volunteers
Time frame: Through 48 hours post-dose on Day 1
Change Over Time in Viral Antigens and DNA in CHB Participants as a Measure of Activity of ARC-521 Injection
Time frame: Baseline to Day 142
2 secondary outcomes
Change Over Time in Cytokine Levels After Single and Multiple Doses of ARC-521 Injection
Time frame: Through 24 hours post-dose (Day 1 for NHVs, and Days 1, 29 & 57 for CHB participants)
Change Over Time in Complement Levels After Single and Multiple Doses of ARC-521 Injection
Time frame: Through 24 hours post-dose (Day 1 for NHVs, and Days 1, 29 & 57 for CHB participants)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing ARC-521 Injection, antihistamine and acetaminophen in people with Hepatitis B, run by Arrowhead Pharmaceuticals at 1 site in New Zealand.
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 9 inclusion and 27 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 12 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 1 site in New Zealand. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 25 Sep 2018). 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?
Number of Participants With Treatment-Emergent Adverse Events (TEAEs): Healthy Volunteers (time frame: From first dose of study drug through Day 29 (± 1 day)). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 12 Jan 2026.