NCT05705427

The COMBAT HBV Feasibility Trial

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

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 317 (actual)
• Sponsor: University of North Carolina, Chapel Hill · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Not accepted

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). 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.

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.

Conditions

• Hepatitis B
• Vertical Transmission of Infectious Disease

Interventions

Type	Name	Description
DRUG	Tenofovir Disoproxil Fumarate 300 MG	Pregnant women in the experimental arm will receive TDF daily beginning in the 3rd trimester of pregnancy and continuing through 1 month postpartum.
BIOLOGICAL	Hepatitis B monovalent vaccine	All infants born to women in the study will receive a birth-dose hepatitis B vaccine.
DRUG	Placebo	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.

Timeline

• Start date: 2023-08-17
• Primary completion: 2025-11-25
• Completion: 2025-11-25
• First posted: 2023-01-30
• Last updated: 2026-02-19

Locations

1 site across 1 country: Democratic Republic of the Congo

Regulatory

• FDA-regulated drug study