Trial Outcomes & Findings for A Hepatitis B Vaccine Challenge Study After Previous Vaxelis® Vaccination (V419-013) (NCT NCT04490499)

NCT ID: NCT04490499

Last Updated: 2022-07-27

Results Overview

Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

207 participants

Primary outcome timeframe

Day 30

Results posted on

2022-07-27

Participant Flow

Approximately 200 planned to be enrolled and 207 were enrolled.

Participant milestones

Participant milestones
Measure
HBVAXPRO™
Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
Overall Study
STARTED
207
Overall Study
Vaccinated
205
Overall Study
COMPLETED
205
Overall Study
NOT COMPLETED
2

Reasons for withdrawal

Reasons for withdrawal
Measure
HBVAXPRO™
Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
Overall Study
Withdrawal by Subject
2

Baseline Characteristics

A Hepatitis B Vaccine Challenge Study After Previous Vaxelis® Vaccination (V419-013)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
HBVAXPRO™
n=207 Participants
Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
Age, Continuous
8.4 years
STANDARD_DEVIATION 0.5 • n=5 Participants
Sex: Female, Male
Female
97 Participants
n=5 Participants
Sex: Female, Male
Male
110 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
205 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=5 Participants
Race (NIH/OMB)
Asian
0 Participants
n=5 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=5 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=5 Participants
Race (NIH/OMB)
White
205 Participants
n=5 Participants
Race (NIH/OMB)
More than one race
2 Participants
n=5 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
Region of Enrollment
Finland
207 Participants
n=5 Participants

PRIMARY outcome

Timeframe: Day 30

Population: The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.

Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.

Outcome measures

Outcome measures
Measure
HBVAXPRO™
n=202 Participants
Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™
99.5 Percentage of Participants
95% Confidence Interval 97.3 • Interval 97.3 to 100.0

SECONDARY outcome

Timeframe: Day 1 and Day 30

Population: The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.

Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.

Outcome measures

Outcome measures
Measure
HBVAXPRO™
n=205 Participants
Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™).
Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen
Day 1 Pre-challenge
9.63 mIU/mL
Interval 7.88 to 11.76
Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen
Day 30 Post-challenge
685.84 mIU/mL
Interval 605.67 to 776.63

Adverse Events

HBVAXPRO™

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Senior Vice President, Global Clinical Development

Merck Sharp & Dohme Corp.

Phone: 1-800-672-6372

Results disclosure agreements

  • Principal investigator is a sponsor employee If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. This allows the Sponsor to protect proprietary information and to provide comments.
  • Publication restrictions are in place

Restriction type: OTHER