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Hepatitis BPhase 4COMBAT-HBVNCT05705427

The COMBAT HBV Feasibility Trial

A Phase 4 study testing Tenofovir Disoproxil Fumarate 300 MG and Hepatitis B monovalent vaccine in people with Hepatitis B and Vertical Transmission of Infectious Disease, run by University of North Carolina, Chapel Hill at 1 site in Democratic Republic of the Congo.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a double-blind, randomized placebo-controlled trial (RCT) of a prophylaxis-for-all approach to prevention of mother-to-child transmission (PMTCT) of hepatitis B virus (HBV) in the Democratic Republic of Congo (DRC). Read more about this study

Who is it for?
Any age
What is being tested?
Tenofovir Disoproxil Fumarate 300 MG and Hepatitis B monovalent vaccine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
317 participants
Where
1 siteDemocratic Republic of the Congo
Study dates
17 Aug 2023to 25 Nov 2025
Phase
Phase 4
Are there results?
None posted in the registry

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 Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • Pregnant women ≥18 years of age who present for routine prenatal care between 28-32 weeks' gestation and who test HBV-positive by point-of-care hepatitis B surface antigen test. Women must intend to seek maternity and postpartum care exclusively at one of the Kinshasa-based study maternity centers.
  • Infants born to enrolled women will be included in the study

Who cannot join

  • Individuals with abnormal creatinine by point-of-care testing
  • Any woman who plans to move outside of Kinshasa Province during the study period.
  • Any HIV-positive individual, determined by routine point-of-care screening at antenatal care visits

Trial locations and contacts

1 site in 1 country.

Democratic Republic of the Congo1 site
  • Université Protestant au Congo

    Kinshasa

Other trials in Democratic Republic of the Congo

About this study

Official title: Simplifying Hepatitis B Care in Pregnancy by Combining Birth-dose Vaccine and Tenofovir: The COMBAT HBV Feasibility Trial

This is a double-blind, randomized placebo-controlled trial (RCT) of a prophylaxis-for-all approach to prevention of mother-to-child transmission (PMTCT) of hepatitis B virus (HBV) in the Democratic Republic of Congo (DRC). HBV-infected pregnant women will be randomized to either receive tenofovir or placebo beginning at 28-32 weeks' gestation and continuing through 4 weeks' postpartum. Women will be followed every 4-6 weeks throughout the prenatal and postpartum period to evaluate for side effects related to the medication. Infants will receive a birth-dose of HBV vaccine, ideally within 24 hours. Participants will be followed longitudinally through 6 months' postpartum.

Read the detailed description

The overall study design is a randomized, double-blind, placebo-controlled trial among two groups of mother-infant dyads: women who receive TDF vs placebo in late pregnancy and the postpartum period (beginning at 28-32 weeks' gestation and continuing through 4 weeks' postpartum). While official World Health Organization (WHO) recommendations are to continue TDF at least through delivery, a range from delivery through 12 weeks' postpartum is possible; the investigators will continue therapy through 4 weeks' postpartum in this study. This feasibility trial will evaluate the acceptability, safety and preliminary effectiveness of a TDF-for-all approach to prevent MTCT of HBV in low-resource settings. HBsAg-positive pregnant women will be enrolled at 28-32 weeks' gestation, and will present for regular medication checks, with a study closeout visit at 24 weeks' postpartum. Study activities at monthly medication checks will include medication refills, assessment of adherence (via pill counts and verbal surveys), and evaluation for side effects. All infants will receive a birth-dose of HBV vaccine within 24 hours of life. MTCT of HBV will be defined as the proportion of infants with positive HBsAg testing at 6 months. This pilot study will provide preliminary data for sample size calculations, including safety and effectiveness data, to prepare for larger RCTs to determine the effectiveness of a tenofovir-for-all approach, as well as the added benefit of tenofovir over birth-dose vaccination.

Being tested
Tenofovir Disoproxil Fumarate 300 MG, Hepatitis B monovalent vaccine, Placebo
Keywords
Prevention of mother-to-child transmission, Hepatitis B birth-dose vaccine, Tenofovir disoproxil fumarate
Medical subject headings
Hepatitis B

What participants receive

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

  • Tenofovir Disoproxil Fumarate 300 MGDrug

    Also called Viread

    Pregnant women in the experimental arm will receive TDF daily beginning in the 3rd trimester of pregnancy and continuing through 1 month postpartum.

  • Hepatitis B monovalent vaccineBiological

    Also called Hepatitis B birth-dose vaccine, Engerix-B

    All infants born to women in the study will receive a birth-dose hepatitis B vaccine.

  • PlaceboDrug

    Pregnant women in the placebo arm will receive a placebo pill daily beginning in the 3rd trimester of pregnancy and continuing through 1 month postpartum.

Study groups in NCT05705427
Study groupRoleWhat they receive
Tenofovir disoproxil fumarate (TDF) armExperimental140 pregnant women in the experimental arm will receive tenofovir disoproxil fumarate (TDF) 300 milligrams (mg) daily, beginning at 28-32 weeks' gestation and continuing through 4 weeks' postpartum. Infants born to these women will be included in this arm and will receive a birth-dose of hepatitis B vaccine.
Receives: Drug: Tenofovir Disoproxil Fumarate 300 MG; Biological: Hepatitis B monovalent vaccine
Placebo armPlacebo comparator140 pregnant women in the placebo arm will receive a placebo pill daily, beginning at 28-32 weeks' gestation and continuing through 4 weeks' postpartum. Infants born to these women will be included in this arm and will receive a birth-dose of hepatitis B vaccine.
Receives: Biological: Hepatitis B monovalent vaccine; Drug: Placebo

What is being measured

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

  1. Safety (Pregnant Women): Number of Pregnant Women With Adverse Effects Related to Study Medications

    Safety of TDF prophylaxis in pregnant women, defined as a composite of adverse events (# mild adverse events [AEs], # moderate-to-severe AEs), presence of side effects and alanine aminotransferase elevations ≥ 5x upper limit of normal

    Measured: Up to study close-out visit, or up to 12 months

  2. Safety (Infants): Number of Infants with Adverse Effects Related to Study Medications

    Safety of maternal TDF for infants, defined as a composite of: Birth weight (grams), mid-upper arm circumference (centimeters), gestational age at delivery (weeks and days), delivery mode (vaginal vs C-section), APGAR scores (0-10), # of adverse events

    Measured: At delivery

  3. Feasibility (Recruitment): Number of Eligible Participants Who Were Enrolled in the Study

    Recruitment is indicative of the number of pregnant women who are screened versus those actually enrolled in the study.

    Measured: Up to study close-out visit, or up to 12 months

  4. Feasibility (Refusal): Number of Eligible Participants Who Refused to Enroll in the Study

    Refusal will be defined as the number of individuals who refuse enrollment upon initial recruitment.

    Measured: Up to study close-out visit, or up to 12 months

  5. Feasibility (Withdrawal): Number of Enrolled Participants Who Withdraw from the Study

    Withdrawal is indicative of the number of enrolled participants who choose not to continue study activities after having been enrolled.

    Measured: Up to study close-out visit, or up to 12 months

  6. Feasibility (Retention): Number of Enrolled Participants Who Remain in the Study Through 6 Months Postpartum

    Retention is defined as the number of participants who remain in the study through the 6-month postpartum visit.

    Measured: Up to study close-out visit, or up to 12 months

  7. Feasibility (Maintenance): Proportion of Study Visits Completed Per Participant

    Adherence to study visits and procedures, defined as proportion of the actual number of visits attended divided by the expected study visits (8) and multiplied by 100.

    Measured: Up to study close-out visit (12 months)

  8. Acceptability (Lab Testing): Number of Mothers With Lab Testing Acceptability Scores >80%

    Number of mothers who report the process of undergoing lab draws as "acceptable" in the exit survey. Range 0-100%, with 0% being unacceptable and 100% being acceptable.

    Measured: Upon study close-out visit, or up to 12 months

  9. Acceptability (Medication): Number of Mothers With Medication Acceptability Scores >80%

    Number of mothers who report the process of taking the study medication as "acceptable" in the exit survey. Range 0-100%, with 0% being unacceptable and 100% being acceptable.

    Measured: Upon study close-out visit, or up to 12 months

  10. Preliminary Effectiveness: Number of Infants With HBV Positivity by Rapid Diagnostic Testing at 6 Months of Life to Indicate Mother-to-Child Transmission of HBV

    Mother-to-child transmission of HBV is defined as HBsAg positivity in the infant at 6 months of life.

    Measured: Measured at 6 months after birth

Secondary outcomes (2)
  1. Sensitivity of the Hepatitis B Core-Related Antigen Test

    Sensitivity will be defined as the number of true positive tests divided by the sum of the true positives and false negatives.

    Measured: Measured at Enrollment

  2. Specificity of the Hepatitis B Core-Related Antigen Test

    Specificity will be defined as the number of true negative tests divided by the sum of the true negatives and the false positives.

    Measured: Measured at Enrollment

Timeline

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

  1. First posted30 Jan 2023
  2. Study start17 Aug 2023
  3. Primary completion25 Nov 2025
  4. Study completion25 Nov 2025

Resources

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 4
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Pregnant women will be randomized at the time of enrollment (at 28-32 weeks' gestation) in a 1:1 ratio to receive tenofovir disoproxil fumarate (TDF) vs placebo, with an expected 140 women in the TDF arm and 140 in the placebo arm. A permuted block randomization technique will be employed to ensure equal distribution between the two arms at the two maternity centers. A biostatistician from the University of North Carolina (UNC) will design the randomization scheme, which will utilize the randomization-and-concealment feature within the REDCap database; the biostatistician will not be directly involved in study enrollment activities. REDCap personnel at UNC will ensure proper design and use of the randomization-and-concealment feature, and study personnel will receive training on the randomization process prior to study roll-out.
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
317 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05705427
Sponsor's protocol ID
22-1492
Acronym
COMBAT-HBV
Status last verified
Feb 2026
First submitted
20 Jan 2023
Last updated
19 Feb 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Datasets will not be made publicly available because they contain protected health information. However, the authors will share de-identified participant data, alongside the study protocol, statistical analysis plan, and analytic code, upon reasonable request and with approval by an independent review committee (ie, learned intermediary). An executed Data Use/Sharing agreement with the University of North Carolina at Chapel Hill (UNC-CH) is required before data will be shared

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Tenofovir Disoproxil Fumarate 300 MG and Hepatitis B monovalent vaccine in people with Hepatitis B and Vertical Transmission of Infectious Disease, run by University of North Carolina, Chapel Hill at 1 site in Democratic Republic of the Congo.

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 2 inclusion and 3 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: finished, as of the sponsor's last update on 19 Feb 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 Democratic Republic of the Congo. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

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

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Safety (Pregnant Women): Number of Pregnant Women With Adverse Effects Related to Study Medications (time frame: Up to study close-out visit, or up to 12 months). The study lists 10 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 19 Feb 2026.

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