Phase 1 Completed N=47 Treatment

First in Human Study of ChAdOx1-HBV in Healthy Participants and Participants With Chronic hepB Infection

Hepatitis B · Healthy

Source: ClinicalTrials.gov NCT04297917 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Aug 2025

Primary outcomePrimary: Incidence of Safety and Reactogenicity Events: Adverse Events — 1; 4; 2; 4 Participants

Summary

This is a Phase 1, first in human study of ChAdOx1-HBV. The study will be conducted in 40 healthy participants and 12 participants with CHB and virally suppressed with oral antiviral medication. This will be an open-label, non randomised dose escalation study comparing the safety, tolerability and immunogenicity of 2 different doses of ChAdOx1 HBV vaccine. T cell responses in healthy participants who have received a prior two-dose series of AZD1222 will be compared with those who have received either the Pfizer COVID 19 vaccine or the Moderna mRNA COVID 19 vaccine.

Outcome Measures

Outcome	Result	p-value
PRIMARY Incidence of Safety and Reactogenicity Events: Adverse Events	1; 4; 2; 4; 8; 8	—
PRIMARY Incidence of Safety and Reactogenicity Events: Serious Adverse Events	0; 0; 0; 0; 0; 0	—
PRIMARY Incidence of Safety and Reactogenicity Events: Grade ≥3 Local Reactions	0; 0; 0; 0; 0; 0	—
PRIMARY Incidence of Safety and Reactogenicity Events: Grade ≥3 Systemic Reactions	5; 4; 6; 5; 15; 11	—
PRIMARY Effect of Prior AZD1222 on the CD8+ T Cell Magnitude and Phenotype as Measured by Multiparameter Flow Cytometry	0.055028; 0.085174; 0.073259; 0.295344; 0.062521; 0.261003	—
SECONDARY Reduction in HBsAg Titre Post-vaccination in CHB Participants	1.019; 0.957; 1.086; 0.814; 0.984; 0.901	—
SECONDARY Loss of Both HBeAg and HBsAg	0; 0; 6; 5	—
SECONDARY Proportion of CHB Participants With HBeAg and HBsAg Seroconversion	0; 0; 6; 5; 0; 0	—
SECONDARY Reduction of Hepatitis B DNA Levels in CHB Participants	0.000; 0.432; -0.333; 0.156; -0.455; 0.432	—
SECONDARY Percentage of CD4+ and CD8+ Expressing IFNγ at Baseline and Days 14, 28, 56, and 84 After Vaccination	0.019; 0.016; 0.013; 0.013; 0.015; 0.048	—
SECONDARY Total T Cell Response to the Core Antigen Encoded by ChAdOx1-HBV as Measured in a Peptide-stimulated ELISpot Assay	30.00; 0.000; 0.000; 18.200; 16.111; 40.000	—
SECONDARY Total T Cell Response to the Pol1-Pol4 Antigen Encoded by ChAdOx1-HBV as Measured in a Peptide-stimulated ELISpot Assay	61.000; 22.500; 6.200; 11.600; 0.000; 0.000	—
SECONDARY Total T Cell Response to the Pre S1/S2 Surface Antigen Encoded by ChAdOx1-HBV as Measured in a Peptide-stimulated ELISpot Assay	279.167; 10.000; 38.200; 20.200; 46.349; 86.364	—
SECONDARY Total T Cell Response to the Sii Surface Antigen Encoded by ChAdOx1-HBV as Measured in a Peptide-stimulated ELISpot Assay	12.500; 0.000; 5.600; 179.042; 5.600; 0.000	—
SECONDARY Effect of Prior AZD1222 on the CD4+ T Cell Magnitude and Phenotype as Measured by Multiparameter Flow Cytometry	0.018525; 0.016409; 0.014959; 0.047705; 0.017065; 0.054382	—
SECONDARY Effect of Prior AZD1222 on the CD8+ T Cell Magnitude and Phenotype as Measured by Multiparameter Flow Cytometry	0.055028; 0.085174; 0.073259; 0.295344; 0.062521; 0.261003	—

Eligibility Criteria

Inclusion Criteria

Adult males or females aged ≥18 to ≤65 years at screening
Body Mass Index ≤30 kg/m2
Able to provide informed consent indicating they understand the purpose of, and procedures required, for the study and are willing to participate
If female, willing not to become pregnant up to 8 weeks after last dose of study vaccine, not breast feeding
If female: Not pregnant, and one of the following:
Of non-childbearing potential (i.e. women who have had a hysterectomy or tubal ligation or are post menopausal, as defined by no menses in ≥1 year)
Sexual abstinence, only if the participant refrains from heterosexual intercourse during the entire study period and it is the usual lifestyle of the participant
Of childbearing potential but agrees to practice highly effective contraception for 4 weeks prior to study vaccine and 8 weeks after study vaccine. Highly effective methods of contraception include one or more of the following:

Male partner who is sterile (medically effective vasectomy) prior to the female participant's entry into the study and is the sole sexual partner for the female participant, Hormonal (oral, intravaginal, transdermal, implantable or injectable), An intrauterine hormone releasing system, An intrauterine device and Bilateral tubal occlusion

Healthy participants (cohorts 1 and 2):

Considered to be healthy with no current conditions that may significantly impair participant safety or influence study results, in the opinion of the Investigator

Participants with well controlled CHB (cohorts 3 and 4):

Documented evidence of chronic HBV infection (e.g. HBsAg positive ≥6 months with detectable HBsAg levels at screening)
Receipt of only either entecavir or tenofovir for at least 12 months before screening
Virally suppressed (HBV DNA 9 kPa within ≤6 months of screening or
Screening FibroTest >0.48 and aspartate aminotransferase (AST) to platelet ratio index of >1 In the event of discordant results between non-invasive methods, the Fibroscan result will take precedence.
Alanine transaminase (ALT) >3 × upper limit of normal, international normalised ratio (INR) >1.5 unless the participant was stable on an anticoagulant regimen affecting INR, albumin 2 mg/dL, platelet count <100,000/mL
A history of liver decompensation (e.g. ascites, encephalopathy or variceal haemorrhage)
Prior or current hepatocellular carcinoma
Chronic liver disease of a non HBV aetiology
Any herbal supplements and or other medicines with potential liver toxicity within the previous 3 months prior to enrolment into this study

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT04297917). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.