- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT02646371
Phase 2b Challenge Study With the Bioconjugate Vaccine Flexyn2a
January 7, 2021 updated by: LimmaTech Biologics AG
Phase 2b, Double-blind, Placebo-controlled Efficacy Challenge Study With a Candidate Bioconjugate Vaccine Against Shigella Flexneri 2a
In this proof of concept challenge study, the bioconjugate candidate vaccine Flexyn2a will be tested for its ability to induce an immune response that protects healthy adult volunteers from infection with a wild-type Shigella flexneri 2a strain compared to subjects receiving placebo.
Study Overview
Status
Completed
Conditions
Intervention / Treatment
Detailed Description
Flexyn2a is a bioconjugate candidate vaccine that is able to induce an humoral immune response specific for the 2a-antigen of Shigella flexneri 2a bacteria.
Healthy adult volunteers naïve for Shigella flexneri 2a infections at screening will receive two administrations of 10 micrograms Flexyn2a or placebo 4 weeks apart.
Four weeks after the second vaccination, each subject will be challenged with 1500 cfu of the virulent Shigella flexneri 2a strain 2457T.
In order to assess the ability of Flexyn2a to protect against infection with this strain, the attack rate of shigellosis in the group vaccinated with Flexyn2a will be compared to the group of the subjects who received placebo injections.
Study Type
Interventional
Enrollment (Actual)
67
Phase
- Phase 2
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
-
-
Maryland
-
Baltimore, Maryland, United States, 21205
- Johns Hopkins Bloomberg School of Public Health, CIR
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
18 years to 50 years (Adult)
Accepts Healthy Volunteers
No
Genders Eligible for Study
All
Description
Inclusion Criteria:
- Male or female age 18-50 years (inclusive)
- Good health, without clinically significant medical history or physical examination findings.
- Negative serum pregnancy test at screening, and negative urine before each vaccination and before challenge for female subjects of childbearing potential.
- Females of childbearing potential must agree to avoid pregnancy by use of effective contraception. Abstinence is not acceptable as effective contraception. Female subjects unable to bear children must have this documented (e.g. tubal ligation or hysterectomy).
- Willingness to participate in the study after all aspects of the protocol have been explained and written informed consent obtained.
- Completion of a training session and demonstrated comprehension of the protocol procedures, knowledge of Shigella-associated illness, and a passing score of 70% or better on a written examination.
- Availability for the study duration, including all planned follow-up visits.
- Willingness to refrain from participating in other studies of investigational products until completion of the last study visit.
Exclusion Criteria:
- Women currently nursing.
- Presence of a significant medical or psychiatric condition which in the opinion of the investigator precludes participation in the study.
- Clinically significant abnormalities in screening hematology or serum chemistry as determined by PI or PI in consultation with the research monitor and sponsor.
- Presence in the serum of HIV antibody, HBs-Ag, or HCV antibody (if confirmed positive by HepC confirmatory test, i.e. RIBA, PCR)
- Evidence of IgA deficiency (serum IgA < 7 mg/dl or limit of detection of assay).
- Evidence of current excessive alcohol consumption or drug dependence.
- Evidence of impaired immune function.
- BMI <19 and ≥35
- Recent vaccination or receipt of an investigational product (within 30 days before vaccination and until last study visit).
- Personal history of an inflammatory arthritis.
- Positive blood test for HLA-B27.
- Personal history of irritable bowel syndrome as defined by Rome III criteria.
- Treatment with immunoglobulins or blood products within 3 months from first candidate vaccine injection.
- Regularly abnormal stool pattern (fewer than 3 per week or more than 3 per day) or loose or liquid stools
- Regular use of laxatives, antacids, or other agents to lower stomach acidity.
- Use of any medication known to affect the immune function (e.g., systemic steroids) within 30 days preceding the first vaccination or planned use during the entire study period.
- Known allergy to any of the following antibiotics: ciprofloxacin, trimethoprim-sulfamethoxazole or penicillin.
- Symptoms consistent with Traveler's Diarrhea concurrent with travel to countries where Shigella infection is endemic (most of the developing world) within two years prior to dosing, OR planned travel to endemic countries during the length of the study.
- Vaccination for or ingestion of Shigella within 3 years prior to vaccination.
- Use of antibiotics during the 7 days before vaccination and challenge
- Use of proton pump inhibitors, H2 blockers or antacids within 48 hours prior to challenge.
- Serum IgG titer to Shigella flexneri 2a LPS ≥ 2500
- Current occupation involving handling of Shigella bacteria
- History of allergy to any vaccine or to soy
- Any other criteria which, in the investigator's opinion, would compromise the ability of the subject to participate in the study, the safety of the study, or the results of the study
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Triple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Active Comparator: Flexyn2a
2 doses of 10 μg of Flexyn2a will be injected intramuscularly 4 weeks apart
|
2 doses of 10 μg of Flexyn2a will be injected intramuscularly 4 weeks apart
|
Placebo Comparator: Placebo
2 doses of TBS solution will be injected intramuscularly 4 weeks apart
|
2 doses of TBS solution will be injected intramuscularly 4 weeks apart
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Attack Rate of Shigellosis in Vaccinated Subjects.
Time Frame: Between Day 56 and Day 64
|
The attack rate of shigellosis after challenge in vaccine group versus in placebo group was analyzed.
|
Between Day 56 and Day 64
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Collaborators
Investigators
- Study Director: Patricia Martin, PhD, LimmaTech Biologics AG
Publications and helpful links
The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start (Actual)
December 1, 2015
Primary Completion (Actual)
September 1, 2016
Study Completion (Actual)
July 1, 2017
Study Registration Dates
First Submitted
December 23, 2015
First Submitted That Met QC Criteria
January 4, 2016
First Posted (Estimate)
January 5, 2016
Study Record Updates
Last Update Posted (Actual)
January 27, 2021
Last Update Submitted That Met QC Criteria
January 7, 2021
Last Verified
January 1, 2021
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- SF2A-2B
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
No
Studies a U.S. FDA-regulated device product
No
product manufactured in and exported from the U.S.
No
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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