A Phase I/II Study to Evaluate the Safety and Immunogenicity of GC3111B in Healthy Adults

Phase 1

Recruiting

• Conditions: Tetanus-diphtheria-acellular Pertussis (Tdap)
• Interventions: Biological: GC3111B; Biological: Boostrix®

• Registration Number: NCT06997627
• Lead Sponsor: GC Biopharma Corp

Brief Summary

This clinical trial consists of two parts: Part 1, which explores safety, and Part 2, which examines both safety and efficacy (immunogenicity). Part 1 is a single-center, open-label, single-group study, while Part 2 is designed as a multicenter, double-blind, randomized, active-controlled trial.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2025-05-15
• Study First Submitted QC: 2025-05-21
• Study First Posted: 2025-05-30
• Status Verified: 2025-06
• Study Start: 2025-06-05
• Last Update Submitted: 2025-06-08
• Last Update Posted: 2025-06-11
• Primary Completion: 2026-05
• Study Completion: 2026-05

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 120

Inclusion Criteria

• Healthy adults aged 19 to 64 years old as of the date of written consent.
• Individuals with no history of vaccination with a vaccine containing diphtheria, tetanus, or pertussis antigens within the past 2 years prior to administration of the investigational product.

Exclusion Criteria

• Individuals who have received a vaccine within 4 weeks prior to administration of the investigational product.
• Individuals with a history of Tdap vaccination prior to administration of the investigational product.
• Pregnant and breastfeeding women.
• Individuals who have participated in other clinical trials involving investigational products/devices within 6 months prior to administration of the investigational product.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
GC3111B	GC3111B	Participants randomized to receive a single dose of GC3111B vaccine.
Boostrix®	Boostrix®	Participants randomized to receive a single dose of Boostrix® vaccine.

Primary Outcome Measures

Name	Time	Method
Unsolicited adverse events occurring by day 28 after administration of the investigational product	28 days after administration of the IP
Solicited adverse events occurring by day 14 after administration of the investigational product	14 days after administration of the IP
Acute adverse events occurring within 30 minutes after administration of the investigational product	30 minutes after administration of the IP
Serious adverse events (SAE) and adverse events of special interest (AESI) occurring up to 180 days after administration of the investigational product	180 days after administration of the IP
Clinically significant findings in vital signs, laboratory tests, 12-lead electrocardiograms, and physical examinations	28 days after administration of the IP

Secondary Outcome Measures

Name	Time	Method
Antibody rates for diphtheria and tetanus on day 28 after administration of the investigational product	28 days after administration of the IP
Boosting response rates for diphtheria, tetanus, and pertussis on day 28 after administration of the investigational product	28 days after administration of the IP	Boosting response rate: 1) If less than 0.1 IU/ml before vaccination, it should be 0.4 IU/ml or higher after the vaccination, or 2) if not less than 0.1 IU/ml before vaccination, it should be 4 times or higher after the vaccination.
Geometric mean concentrations (GMC) of antibodies against diphtheria, tetanus, and pertussis antitoxins (anti-PT, anti-FHA, anti-PRN) on day 28 after administration of the investigational product	28 days after administration of the IP

Trial Locations

Locations (1)

The Catholic Univ. of Korea Eunpyeong St. Mary's Hospital; 🇰🇷 Seoul, Korea, Republic of