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CompletedNCT05178134Updated Aug 19, 2025Results posted

A Phase 2 Bridging Study to Assess the New Formulation of ETVAX

A Phase 2 interventional study of Etvax and Etvax in Healty Volunteers and Preventable Disease, Vaccine, sponsored by Scandinavian Biopharma AB. Completed at 1 site in Sweden. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-08-19.

Sponsored by Scandinavian Biopharma AB · Phase 2, Interventional, and Prevention

Phase
Phase 2
Study type
Interventional
Enrollment
280
Allocation
Randomized
Ages
18 Years to 50 Years
Sex
All
01

Study summary

This is a phase 2,prospective double-blind, randomized, parallel-group study with the aim to demonstrate non-inferiority, in terms of immunogenicity, between the wet formulation and a newly developed partially dried formulation of selected components of ETVAX.

Read the detailed description

This is a phase 2, prospective double-blind, randomized, parallel-group study with the aim to demonstrate non-inferiority, in terms of immunogenicity, between the wet formulation and a newly developed partially dried formulation of selected components of ETVAX. A total number of 126 subjects is planned to be included in each arm of the study, i.e. 252 subjects in total. Assuming a 10% dropout rate the target number of subjects to be recruited per study arm is therefore 140, i.e. 280 subjects in total. Healthy volunteers between 18-50 years will be eligible for enrolment into the study.

Eligible subjects will be randomized on Day 1 (Visit 2) to receive either of the two oral formulations of ETVAX (1:1) and consecutively included the study. The treatment allocation (Wet formulation/Partially dried formulation) will be double-blind. The study subjects will receive two oral doses, two weeks apart (Day 1/Visit 2 and Day 15 /Visit 3).The dosing will occur at the clinic (CTC in Gothenburg, Sweden). A follow-up visit will be performed 7 days after the last (second) dose in all study subjects

The primary endpoint to be measured for each patient in the study is response (yes/no) to a vaccine. A vaccine responder will be defined by a ≥2-fold increase in IgA and/or IgG antibody levels against LTB in serum between post- compared to pre-immunization samples. The response rates (seroconversion rates) of IgA and/or IgG anti-LTB antibodies in serum will be derived and compared between the two treatment groups.

The secondary endpoint to be measured for each patient in the study is the occurrence of solicited symptoms for six days after each vaccination (day of vaccination and five subsequent days).

Exploratory analyses will be done to evaluate if ETVAX vaccination induces circulating antigen specific memory B- and/or T cells that can be assessed using recently established laboratory assays.

For the exploratory analyses, subgroups of subjects (n=20-40, evenly distributed between the two treatment arms) will participate in additional follow-up visits 5± 1, 30± 7 and 90± 14 days after the second dose. Blood samples will be collected on all exploratory visits. The extra visits and analyses for exploratory analyses may continue after the main part of the study has been completed and the database locked.

02

Conditions studied

  • Healty Volunteers
  • Preventable Disease, Vaccine

Keywords

  • Prophylaxis against diarrhea due to enterotoxigenic E. coli
03

In context

Vaccine-Preventable Diseases

51 studies on the registry are indexed under Vaccine-Preventable Diseases; 13 are open to participants now.

This study's enrollment of 280 is above the median of 165 across 38 interventional studies indexed under Vaccine-Preventable Diseases.

Browse Vaccine-Preventable Diseases studies →

Lead sponsor

Scandinavian Biopharma AB is the lead sponsor of 3 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 50 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Male or female aged 18-50 years, inclusive at the time of signing the informed consent.
  • Healthy constitution as established by medical history and physical examination.
  • Willing and able to give written informed consent for participation in the study.
  • Able to comply with study activities, as judged by the Investigator.
  • Female Participants:
  • Women of child-bearing potential (for definition see Section 9.3.6 in the protocol):
  • Have to agree to use an acceptable birth control method during participation in the investigation (see Section 9.3.6).
  • A negative pregnancy test (beta human chorionic gonadotropin dipstick test in urine) at Visit 2/Day 1 will be required.
  • Male Participants:
  • Have to agree to remain abstinent (refrain from heterosexual intercourse) or use a condom, and agreement to refrain from donating sperm, as defined in Section 9.3.6

Exclusion criteria

Exclusion criteria

  • An acute or chronic medical condition that, in the opinion of the investigator/physician, would render ingestion of the investigational products unsafe or would interfere with the evaluation of responses. This includes, but is not limited to gastrointestinal diseases, and autoimmune diseases.
  • Current malignancy or history of malignancy during the last five years, based on anamnesis.
  • Gastroenteritis within two weeks prior to vaccination.
  • Regular use of laxatives, antacids or other agents that lower stomach acidity.
  • Any planned major surgery during the duration of the study.
  • After 10 minutes supine rest, any vital signs outside the following ranges:
  • Systolic BP > 160 mm Hg
  • Diastolic BP > 100 mm Hg
  • Heart rate \< 40 or >85 beats per minute
  • Antibiotic therapy within two weeks prior to the vaccination.
  • Known Hepatitis A, B, C, and/or HIV infection.
  • Concomitant intake of immunomodulating drugs during the study period or less than 3 months prior to the first immunization, with the following exceptions: oral anti-histamines are not allowed during the study period or less than 3 weeks prior to the first immunization. Local anti-histamine treatment is allowed during the study period.
  • Any other significant medical conditions (e.g. poorly controlled psychiatric condition) judged by the Investigator to preclude entry.
  • Intends to receive any other vaccine during the study period, or within two weeks prior to trial vaccination.
  • Has previously received Dukoral or any type of ETEC or cholera vaccines.
  • Brought up in ETEC-endemic areas (e.g., urban and rural areas of Central and South America, Caribbean, most countries in Asia, Africa, etc.).
  • Has travelled to ETEC-endemic areas within the last 3 years OR spent > two months in ETEC endemic areas during the last 10 years.
  • Intends to travel to ETEC endemic countries during the study period.
  • Known or suspected history of drug, chemical or alcohol abuse, as deemed by the investigator/physician.
  • History of severe allergy/hypersensitivity or ongoing allergy/hypersensitivity, as judged by the Investigator, or history of hypersensitivity to drugs with a similar chemical structure or class to ETVAX®.
  • Participation in any other clinical study that included drug treatment with the last administration within the past 3 months prior to administration of study treatment in this study. Patients consented and screened but not dosed in previous clinical studies are not excluded.
  • Concomitant participation in any other clinical study.
  • Females who are pregnant as determined by urine test at inclusion and prior to each vaccination.
  • Females who are nursing.
  • Unable to participate in all study visits.
  • Any condition or circumstance which would make the subject unsuitable for participation in the study in the opinion of the investigator/physician.
05

Study design

Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Care provider, Investigator)
Enrollment
280 participants (actual)

Study arms

  • Active comparator
    The wet formulation of ETVAX.

    The wet formulation consists of a liquid suspension of inactivated bacteria (ETEX 21-24) and LCTBA in one vial, freeze-dried dmLT adjuvant in a second vial, and effervescent buffer granules in a separate sachet. Prior to administration, the buffer is dissolved in 150 ml tap water, followed by the addition of the content of the vaccine vial (inactivated bacteria mixed with LCTBA) and reconstituted and diluted adjuvant dmLT from the second vial.

    Biological: Etvax

  • Active comparator
    The partially dried formulation of selected components of ETVAX.

    The partially dried formulation, dmLT and LCTBA are spray-dried and mixed with the buffer granules and stabilizing excipients in a sachet. Prior to administration, the content of the buffer sachet (buffer, dmLT, and LCTBA) is dissolved in 150 ml tap water, followed by the addition of a liquid suspension of inactivated bacteria (ETEX 21-24).

    Biological: Etvax

Interventions

  • BiologicalEtvax

    Preparation of complete Wet formulation. The vaccine supplied as a liquid, is mixed with the 150 ml of sodium bicarbonate buffer solution on the day of preparation for use on dosing day. Just prior to administration 10 µg of dmLT is added by pipette (50 µl).

  • BiologicalEtvax

    Preparation of partially dry formulation. The partially dry formulation of vaccine is prepared by adding the effervescent powder containing the dmLT and LCTBA to 150 ml of water. After mixing, the content of the vaccine vial is added to the mixture and the vaccine is administered to the volunteer within 30 minutes after adding the buffer powder to the water.

06

What researchers measure

Primary outcomes

  1. Vaccine Response

    The primary endpoint to be measured for each patient in the study is response (yes/no) to a vaccine. A vaccine responder will be defined by a ≥2-fold increase in IgA and/or IgG antibody levels against LTB in serum between post- compared to pre-immunization samples. The response rates (seroconversion rates) of IgA and/or IgG anti-LTB antibodies in serum will be derived and compared between the two treatment groups.

    Time frame: 3 weeks

Secondary outcomes

  1. Solicited Symptoms After Vaccination

    Occurrence of solicited symptoms for six days after each vaccination (day of vaccination and five subsequent days).

    Time frame: 3 weeks

Other outcomes

  1. Levels of IgA and IgG Antibodies Mononuclear Cells (PBMCs)

    Evaluation if ETVAX® vaccination induces circulating antigen specific memory B- and/or T cells.

    Time frame: 3 months

07

Results

Posted Aug 19, 2025

Participant flow

Participant flow — Overall Study
MilestoneThe Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.
Started140140
Completed139139
Not completed11

Outcome measures

PrimaryVaccine Response

The primary endpoint to be measured for each patient in the study is response (yes/no) to a vaccine. A vaccine responder will be defined by a ≥2-fold increase in IgA and/or IgG antibody levels against LTB in serum between post- compared to pre-immunization samples. The response rates (seroconversion rates) of IgA and/or IgG anti-LTB antibodies in serum will be derived and compared between the two treatment groups.

Time frame:
3 weeks
Reported as:
Count of participants · Participants
Vaccine Response
ParticipantsThe Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.
Vaccine Response116110
Statistical analysis
  • The Wet Formulation of ETVAX. vs The Partially Dried Formulation of Selected Components of ETVAX. · Difference in response rates: -0.020 · 95% CI -0.108 to 0.069
SecondarySolicited Symptoms After Vaccination

Occurrence of solicited symptoms for six days after each vaccination (day of vaccination and five subsequent days).

Time frame:
3 weeks
Reported as:
Count of participants · Participants
Solicited Symptoms After Vaccination
ParticipantsThe Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.
Subjects who experienced solicited AEs within 6 days after first dose — Abdominal pain2322
Subjects who experienced solicited AEs within 6 days after first dose — Nausea1720
Subjects who experienced solicited AEs within 6 days after first dose — Vomiting33
Subjects who experienced solicited AEs within 6 days after first dose — Loose stools/Diarrhea2433
Subjects who experienced solicited AEs within 6 days after first dose — Fever30
Subjects who experienced solicited AEs within 6 days after first dose — No solicited symptom7062
Subjects who experienced solicited AEs within 6 days after second dose — Abdominal pain2412
Subjects who experienced solicited AEs within 6 days after second dose — Nausea2220
Subjects who experienced solicited AEs within 6 days after second dose — Vomiting45
Subjects who experienced solicited AEs within 6 days after second dose — Loose stools/Diarrhea2724
Subjects who experienced solicited AEs within 6 days after second dose — Fever30
Subjects who experienced solicited AEs within 6 days after second dose — No solicited symptom5978
Other pre-specifiedLevels of IgA and IgG Antibodies Mononuclear Cells (PBMCs)

Evaluation if ETVAX® vaccination induces circulating antigen specific memory B- and/or T cells.

Time frame:
3 months

Results for this outcome have not been posted.

Adverse events

Collected over Collection of unsolicited AEs started with the first intervention with the study vaccine and continued until the last follow-up assessment 7 days (6-10 days) after study vaccine dose 2.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
The Wet Formulation of ETVAX.0/140 (0%)0/140 (0%)107/140 (76.4%)
The Partially Dried Formulation of Selected Components of ETVAX.0/140 (0%)0/140 (0%)102/140 (72.9%)
Most frequent other events
Showing 10 of 83
Most frequent other events
EventThe Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.
HeadacheNervous system disorders43/14040/140
DiarrhoeaGastrointestinal disorders41/14042/140
Abdominal painGastrointestinal disorders36/14030/140
NauseaGastrointestinal disorders32/14033/140
FlatulenceGastrointestinal disorders19/14014/140
DysmenorrhoeaReproductive system and breast disorders13/1405/140
NasopharyngitisInfections and infestations12/14011/140
FatigueGeneral disorders7/1405/140
PyrexiaGeneral disorders7/1400/140
VomitingGastrointestinal disorders7/1406/140

Baseline characteristics

Age, Continuous
Age, Continuous(Years)The Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.Total
Mean31.0 ± 9.7032.2 ± 9.5431.6 ± 9.62
Sex: Female, Male
Sex: Female, Male(Participants)The Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.Total
Female8687173
Male5453107
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)The Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.Total
Hispanic or Latino112
Not Hispanic or Latino139139278
Unknown or Not Reported000
Region of Enrollment
Region of Enrollment(participants)The Wet Formulation of ETVAX.The Partially Dried Formulation of Selected Components of ETVAX.Total
Sweden140140280
08

Study locations

1 site
  • Clinical Trial Center, CTC
    Gothenburg, 41346, Sweden
09

References and documents

Study documents

  • Protocol and statistical analysis plan · Jun 23, 2022

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 19, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT05178134
Lead sponsor
Scandinavian Biopharma AB
Collaborators
Göteborg University, Aurevia, Sahlgrenska University Hospital
Responsible party
Sponsor
First posted
Jan 5, 2022
Start date
Nov 8, 2021
Primary completion
Oct 20, 2022
Completion
Oct 20, 2022
Results posted
Aug 19, 2025
Last update
Aug 19, 2025

Study contacts

Dan Curiac, MD
principal investigator · Clinical Trial Center, CTC, Gothia Forum

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Aug 2025. You cannot join it, but the record below documents what was studied.

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