Safety and Immunogenicity of Artificial Invaplex (Shigella Flexneri 2a InvaplexAR)

February 10, 2021 updated by: U.S. Army Medical Research and Development Command

A Phase 1 Open-label, Dose Escalating Study of Artificial Shigella Flexneri 2a InvaplexAR Administered Intranasally to Healthy, Adult Volunteers to Evaluate Safety and Immunogenicity

This study is an open-label, dose-escalating Phase 1 investigation of S. flexneri 2a InvaplexAR vaccine. A total of up to 40 subjects will receive one of four S. flexneri 2a InvaplexAR vaccine doses. The vaccine will be administered intranasally (without adjuvant).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The vaccine will be administered on Days 0,14, and 28. Volunteers (10 per group [8 minimum]) will receive the same dose at each vaccination dependent upon group assignment. Groups will be divided according to the table below. An interval no less than 1 week will separate the third dose of a group from the first dose of the next group (receiving an increased InvaplexAR dose). Blood, stool, and saliva specimens will be collected at pre-specified intervals to examine systemic and mucosal vaccine antigen-specific immune responses. Ocular tear samples will be collected in groups C and D. Vaccine safety will be actively monitored during vaccination and for 28 days following the third vaccine dose. The decision to advance to the next dose level is based on the safety assessment (not immunogenicity). A dose level with no occurrence of stopping criteria in the 7 days following the last vaccine dose will prompt moving to the next higher level. All safety data will be summarized and reviewed with the research monitor prior to dose escalation. In addition, a report of all safety data will be provided to the sponsor's safety office for informational purposes.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
38

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

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

  • United States
    • Maryland
      • Silver Spring, Maryland, United States, 20910
        • Walter Reed Army Institute of Research, Clinical Trials Center

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy, adult, male or female, age 18 to 45 years (inclusive) at the time of enrollment.
  • Completion and review of comprehension test (achieved > 70% accuracy).
  • Signed informed consent document.
  • Available for the required follow-up period and scheduled clinic visits.
  • Women: Negative pregnancy test with understanding (through informed consent process) to not become pregnant nor to breastfeed during the study or within 3 months following last vaccination

Exclusion Criteria:

  • Health problems (for example, chronic medical conditions such as psychiatric conditions, diabetes mellitus, hypertension, or any other conditions that might place the subjects at increased risk of adverse events)- study clinicians, in consultation with the PI, will use clinical judgment on a case-by-case basis to assess safety risks under this criterion. The PI will consult with the Research Monitor as appropriate.
  • Clinically significant abnormalities on physical examination (chronic sinusitis or seasonal rhinitis) which compromise identification and interpretation of potential vaccine associated adverse effects.
  • Use of immunosuppressive and/or immunomodulative drugs such as corticosteroids or chemotherapeutics that may influence antibody development.
  • Immunosuppressive illnesses (including IgA deficiency defined by serum IgA below level of detection or <7mg/dL).
  • Participation in research involving another investigational product (defined as receipt of an investigational product or exposure to an invasive investigational device) 30 days before planned date of first vaccination or anytime throughout the duration of the study until the last study safety visit.
  • Positive blood test for HBsAG, HCV, HIV-1/HIV-2.
  • Clinically significant abnormalities on basic laboratory screening.
  • Presence of significant unexplained laboratory abnormalities that in the opinion of the PI may potentially confound the analysis of the study results.
  • Current smoker or smoker in past 1 year ('smoker' defined as daily cigarette, cigar, or pipe use for a period of at least 1 month).

Research specific

  • Structural abnormalities on sinus/nasal cavity examination.
  • Rhinoplasty.
  • Nasal polyps.
  • Nasal ulcers.
  • Deviated nasal septum. This question is being used to determine whether the volunteer has a clinically significant deviated septum that causes nasal obstruction (thereby causing difficulty breathing), interferes with normal sinus drainage, or obscures visualization of the posterior nasal cavity complicating examination and safety monitoring..
  • Chronic sinusitis/rhinitis.
  • Current or planned use of nasal topical corticosteroids and/or nasal spray medications in the 4 weeks prior to dosing or during the study vaccination period.
  • Current or recent history (in the past 5 years) of reactive airway disease (asthma), chronic obstructive pulmonary disease, or chronic bronchitis.
  • History of Bell's palsy.
  • Chronic use (weekly or more often) of anti-diarrheal, anti-constipation, or antacid therapy (excluding use associated with spicy meals).
  • Abnormal stool pattern (fewer than 3 stools per week or more than 3 stools per day) on a regular basis; loose or liquid stools on other than an occasional basis.
  • Personal or family history of inflammatory arthritis.
  • Positive blood test for HLA-B27.
  • History of allergy to any vaccine.

Prior Exposure to Shigella

  • Serum IgG titer ≥ 2500 to Shigella flexneri 2a LPS.
  • History of microbiologically confirmed Shigella infection in the past 3 years.
  • Received previous experimental Shigella vaccine or live Shigella challenge.
  • Travel to countries with symptoms of travelers' diarrhea where Shigella or other enteric infections are endemic (most of the developing world) within the past 6 months prior to dosing.
  • Occupation involving handling of Shigella bacteria currently, or in the past 3 years.

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: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: 10 μg S. flexneri 2a Invaplex
10 subjects vaccinated on days 0, 14, 28
Biological: Shigella flexneri 2a InvaplexAR
The investigational product is S. flexneri 2a InvaplexAR. The product is composed of three individual components IpaB, IpaC, and LPS. The components were assembled into the high molecular weight S. flexneri 2a InvaplexAR complex and subsequently purified by ion-exchange chromatography yielding a bulk lot.
Active Comparator: 50 μg S. flexneri 2a Invaplex
10 subjects vaccinated on days 0, 14, 28
Biological: Shigella flexneri 2a InvaplexAR
The investigational product is S. flexneri 2a InvaplexAR. The product is composed of three individual components IpaB, IpaC, and LPS. The components were assembled into the high molecular weight S. flexneri 2a InvaplexAR complex and subsequently purified by ion-exchange chromatography yielding a bulk lot.
Active Comparator: 250 μg S. flexneri 2a Invaplex
10 subjects vaccinated on days 0, 14, 28
Biological: Shigella flexneri 2a InvaplexAR
The investigational product is S. flexneri 2a InvaplexAR. The product is composed of three individual components IpaB, IpaC, and LPS. The components were assembled into the high molecular weight S. flexneri 2a InvaplexAR complex and subsequently purified by ion-exchange chromatography yielding a bulk lot.
Active Comparator: 500 μg S. flexneri 2a Invaplex
10 subjects vaccinated on days 0, 14, 28
Biological: Shigella flexneri 2a InvaplexAR
The investigational product is S. flexneri 2a InvaplexAR. The product is composed of three individual components IpaB, IpaC, and LPS. The components were assembled into the high molecular weight S. flexneri 2a InvaplexAR complex and subsequently purified by ion-exchange chromatography yielding a bulk lot.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of Treatment Related Adverse Events
Time Frame: 166 days
Number of adverse events related to the vaccine for each arm
166 days
Antibody Titers Against IgG and IgA Immunizing Antigens
Time Frame: At screening and Days 0, 14, 28, 35, 42, and 56
Serum samples will be assayed for antibody titers against the immunizing antigens LPS, IpaB, IpaC, and S. flexneri 2a Invaplex at screening, and Days 0, 14, 28, 35, 42, and 56 for 36 subjects. Previously established high-titer specimens will be included on each plate to track day to day interassay variation. For each antigen, pre- and post-vaccination serum samples will be assayed side-by-side. The antibody titer assigned to each sample will represent the geometric mean of duplicate tests performed on 2 different days. Reciprocal endpoint titers < 5 will be assigned a value of 2.5 for computational purposes. Seroconversion will be defined as a > 4-fold increase in endpoint titer between pre-and post-vaccination samples AND a post-vaccination reciprocal titer >10.
At screening and Days 0, 14, 28, 35, 42, and 56

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
IgG and IgA Antigen-Specific Antibody Secreting Cell (ASC) Mucosal Responses
Time Frame: 56 Days
ASC responses were assessed using isolated peripheral blood mononuclear cells (PBMCs). For each antigen, pre- and post-vaccination samples were tested on the same plates for total and vaccine-specific numbers. The ASC responses indirectly reflect intestinal immune responses through measurement of antigen-specific B-lymphocytes in systemic circulation before homing to gut effector sites. An ASC response was defined as > 10 ASCs above baseline.
56 Days
IgG and IgA Antigen-Specific Antibody Lymphocyte Supernatant (ALS) Mucosal Responses
Time Frame: 56 Days
ALS responses were assessed using isolated peripheral blood mononuclear cells (PBMCs). For each antigen, pre- and post-vaccination samples were tested on the same plates for total and vaccine-specific numbers. The ALS responses indirectly reflect intestinal immune responses through measurement of antigen-specific B-lymphocytes in systemic circulation before homing to gut effector sites. An ALS response was defined as a ≥ 4-fold increase over baseline ALS titers.
56 Days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
U.S. Army Medical Research and Development Command

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Christopher Duplessis, MD, MPH, MS, Enteric Diseases Department Naval Medical Research Center

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2015

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 13, 2016

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 13, 2016

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 13, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 14, 2015

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 15, 2015

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 12, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2021

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • S-15-19
  • A-18716 (Other Identifier: Walter Reed Army Institute of Research)
  • NMRC.2015.0003 (Other Identifier: Naval Medical Research Center)

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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