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Dose-Finding Study of CS19 Expressing ETEC Challenge Strains

Primary Purpose

Travelers' Diarrhea

Status
Completed
Phase
Phase 1
Locations
United States
Study Type
Interventional
Intervention
CS19 expressing ETEC strain
Sponsored by
Johns Hopkins Bloomberg School of Public Health
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional other trial for Travelers' Diarrhea focused on measuring Diarrhea, ETEC

Eligibility Criteria

18 Years - 45 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  1. Male or female between 18 and 45 years of age, inclusive.
  2. General good health, without significant medical illness, abnormal physical examination findings or clinical laboratory abnormalities as determined by principal investigator (PI) or PI in consultation with the medical monitor and Sponsor.
  3. Demonstrate comprehension of the protocol procedures and knowledge of ETEC illness by passing a written examination (pass grade ≥ 70%)
  4. Willing to participate after informed consent obtained.
  5. Available for entire inpatient portion of study and all outpatient study visits.
  6. Negative serum pregnancy test at screening (initial visit and day -7 to - 3) and a negative urine pregnancy test on the day of admission to the inpatient phase for female subjects of childbearing potential. Females of childbearing potential must agree to use an efficacious hormonal or barrier method of birth control during the study. Alternatively, abstinence alone is acceptable. Female subjects who are unable to bear children must provide supporting documentation (e.g., prior tubal ligation or hysterectomy).

Exclusion Criteria:

  1. Presence of a significant medical condition, (e.g., psychiatric conditions or gastrointestinal disease, such as peptic ulcer, symptoms or evidence of active gastritis or gastroesophageal reflux disease, inflammatory bowel disease, alcohol or illicit drug abuse/dependency), or other laboratory abnormalities which in the opinion of the investigator precludes participation in the study.
  2. Immunosuppressive illness or IgA deficiency (below the normal limits)
  3. Positive serology results for HIV, HBsAg, or HCV antibodies.
  4. Significant abnormalities in screening laboratory hematology, serum chemistry, urinalysis, as determined by PI or PI in consultation with the medical monitor and Sponsor.
  5. Allergy to fluoroquinolones, cotrimoxazole, or ampicillin/penicillin (excluded if allergic to two of three).
  6. Fewer than 3 stools per week or more than 3 stools per day as the usual frequency; loose or liquid stools other than on an occasional basis.
  7. History of diarrhea in the 2 weeks prior to planned inpatient phase.
  8. Regular use of laxatives or any agent that increases gastric pH (regular defined as at least weekly).
  9. Use of antibiotics during the 7 days before bacterial dosing or proton pump inhibitors, H2 blockers, or antacids within 48 hours of dosing.
  10. Travel to countries where ETEC or cholera infection is endemic (most of the developing world) within two years prior to dosing.
  11. History of vaccination for or ingestion of ETEC, cholera, or LT toxin.
  12. Stool culture (collected no more than 1 week prior to admission) positive for ETEC or other bacterial enteric pathogens (Salmonella, Shigella and Campylobacter).
  13. Use of any investigational product within 30 days preceding the receipt of the challenge inoculum, or planned use during the active study period.
  14. Use of any medication known to affect the immune function (e.g., corticosteroids) within 30 days preceding receipt of the challenge inoculum or planned use during the active study period. (Topical and intra-articular steroids will not exclude subjects). MANAGEMENT

Sites / Locations

  • Center for Immunization Research - Johns Hopkins Bloomberg School of Public Health
  • General Clinical Research Center of the Johns Hopkins Hospital

Arms of the Study

Arm 1

Arm Type

Other

Arm Label

CS19 expressing ETEC strain

Arm Description

Ascending dose finding study in 5-10 subjects per dose; to identify the dose able to give a diarrheal attack rate greater than or equal to 80%.

Outcomes

Primary Outcome Measures

Develop of diarrhea.

Secondary Outcome Measures

Development of moderate to severe diarrhea

Full Information

First Posted
November 26, 2007
Last Updated
April 3, 2017
Sponsor
Johns Hopkins Bloomberg School of Public Health
Collaborators
Naval Medical Research Center
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1. Study Identification

Unique Protocol Identification Number
NCT00564863
Brief Title
Dose-Finding Study of CS19 Expressing ETEC Challenge Strains
Official Title
Strain and Dose-Finding Study of DS26-1 and WS0115A Enterotoxigenic E. Coli (ETEC) Challenge Strains That Express CS19 Fimbriae
Study Type
Interventional

2. Study Status

Record Verification Date
April 2017
Overall Recruitment Status
Completed
Study Start Date
September 2007 (Actual)
Primary Completion Date
May 2008 (Actual)
Study Completion Date
September 4, 2008 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Johns Hopkins Bloomberg School of Public Health
Collaborators
Naval Medical Research Center

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
This will be a strain and dose-finding study in which CS19-ETEC strain WS0115A will be administered at a starting inoculum of 5 x 108 colony forming units (cfu) to 5 subjects as the initial step to establish a human disease model. If an 80% attack rate (AR) for predefined diarrheal disease is achieved without high output diarrhea, the same inoculum will be given to 5 - 10 more subjects for confirmation of AR. If an 80% AR is not achieved, AR and severity of disease will be evaluated to determine if the dose should be increased. The same sequence may be conducted with DS26-1 as necessary. If the WS0115A strain causes high output diarrhea, the dose will be adjusted down and further dose characterization continued. An iterative process will be used to select the optimal strain and dose with each step reviewed and approved by the medical monitor.
Detailed Description
This is a phase 1, open-label, strain and dose-finding study designed to establish a human challenge modelfor CS19-ETEC that causes a > 80% attack rate without causing high output diarrhea. This study design is identical to that of the CS17 challenge model recently completed. Two strains of CS19-ETEC isolated from human diarrheal cases have been identified and characterized. Each clinical isolate was used to generate a cGMP MCB and procedures were established to create a fresh inoculum to administer orally in a sodium bicarbonate solution for challenge. Refer to Section 8 for full details on the isolation and preparation of these strains. CS19-ETEC strain WS0115A (toxin phenotype of LT+ ST+ and serotype O114:H-) will be the lead strain and will be administered orally to an initial cohort of 5 subjects. This strain was isolated from the stool of a 12-month-old Egyptian girl suffering from watery diarrhea identified during a surveillance study conducted in Abees, Egypt from 1993 to 1995 by investigators at the Naval Medical Research Unit-3 (NAMRU-3), Cairo, Egypt. A negative microbiologic work-up for copathogens (other bacterialenteropathogens, rotavirus, Giardia lamblia, Entamoeba histolytica, and Cryptosporidium) supports that the isolated WS0115A strain was pathogenic in this child. Since this strain has an LT+ST+ toxin phenotype, it is the preferred strain to lead in testing the challenge model, since heterologous protection by bovine milk IgG anti-CsbD against an LT+ST+ phenotype would offer a more robust test of the protection afforded by anti-colonization. The alternate strain, CS-19 ETEC strain DS26-1 (toxin phenotype LT+ST-;serotype O8:H9) was isolated in 1990 at the U.S. Navy Forward Laboratory from a U.S. soldier with diarrhea while on deployment to Saudi Arabia during Operation Desert Shield. A negative microbiologic work-up for copathogens (Salmonella typhi, Vibrio cholerae, Giardia lamblia or Entamoeba histolytica)supports that the isolated DS26-1 strain was pathogenic in this individual. Each clinical isolate was used to generate a cGMP master cell bank and procedures were established to create a fresh inoculum to administer orally in a sodium bicarbonate solution for challenge. Refer to Section 8 for full details on the isolation and preparation of these strains.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Travelers' Diarrhea
Keywords
Diarrhea, ETEC

7. Study Design

Primary Purpose
Other
Study Phase
Phase 1
Interventional Study Model
Single Group Assignment
Model Description
This is a phase 1, open-label, strain and dose-finding study designed to establish a human challenge model for CS19-ETEC that causes a > 80% attack rate without causing high output diarrhea. This will be a strain and dose-finding study in which CS19-ETEC strain WS0115A will be administered at a starting inoculum of 5 x 108 colony forming units (cfu) to 5 subjects as the initial step to establish a human disease model. If an 80% attack rate (AR) for predefined diarrheal disease is achieved without high output diarrhea, the same inoculum will be given to 5 - 10 more subjects for confirmation of AR. If an 80% AR is not achieved, AR and severity of disease will be evaluated to determine if the dose should be increased. The same sequence may be conducted with DS26-1 as necessary.
Masking
None (Open Label)
Allocation
N/A
Enrollment
25 (Actual)

8. Arms, Groups, and Interventions

Arm Title
CS19 expressing ETEC strain
Arm Type
Other
Arm Description
Ascending dose finding study in 5-10 subjects per dose; to identify the dose able to give a diarrheal attack rate greater than or equal to 80%.
Intervention Type
Biological
Intervention Name(s)
CS19 expressing ETEC strain
Intervention Description
Wild type ETEC strain expressing the colonization faction CS19, and LT and ST enterotoxins.
Primary Outcome Measure Information:
Title
Develop of diarrhea.
Time Frame
120 hours after challenge
Secondary Outcome Measure Information:
Title
Development of moderate to severe diarrhea
Time Frame
120 hours after challenge

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
45 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Male or female between 18 and 45 years of age, inclusive. General good health, without significant medical illness, abnormal physical examination findings or clinical laboratory abnormalities as determined by principal investigator (PI) or PI in consultation with the medical monitor and Sponsor. Demonstrate comprehension of the protocol procedures and knowledge of ETEC illness by passing a written examination (pass grade ≥ 70%) Willing to participate after informed consent obtained. Available for entire inpatient portion of study and all outpatient study visits. Negative serum pregnancy test at screening (initial visit and day -7 to - 3) and a negative urine pregnancy test on the day of admission to the inpatient phase for female subjects of childbearing potential. Females of childbearing potential must agree to use an efficacious hormonal or barrier method of birth control during the study. Alternatively, abstinence alone is acceptable. Female subjects who are unable to bear children must provide supporting documentation (e.g., prior tubal ligation or hysterectomy). Exclusion Criteria: Presence of a significant medical condition, (e.g., psychiatric conditions or gastrointestinal disease, such as peptic ulcer, symptoms or evidence of active gastritis or gastroesophageal reflux disease, inflammatory bowel disease, alcohol or illicit drug abuse/dependency), or other laboratory abnormalities which in the opinion of the investigator precludes participation in the study. Immunosuppressive illness or IgA deficiency (below the normal limits) Positive serology results for HIV, HBsAg, or HCV antibodies. Significant abnormalities in screening laboratory hematology, serum chemistry, urinalysis, as determined by PI or PI in consultation with the medical monitor and Sponsor. Allergy to fluoroquinolones, cotrimoxazole, or ampicillin/penicillin (excluded if allergic to two of three). Fewer than 3 stools per week or more than 3 stools per day as the usual frequency; loose or liquid stools other than on an occasional basis. History of diarrhea in the 2 weeks prior to planned inpatient phase. Regular use of laxatives or any agent that increases gastric pH (regular defined as at least weekly). Use of antibiotics during the 7 days before bacterial dosing or proton pump inhibitors, H2 blockers, or antacids within 48 hours of dosing. Travel to countries where ETEC or cholera infection is endemic (most of the developing world) within two years prior to dosing. History of vaccination for or ingestion of ETEC, cholera, or LT toxin. Stool culture (collected no more than 1 week prior to admission) positive for ETEC or other bacterial enteric pathogens (Salmonella, Shigella and Campylobacter). Use of any investigational product within 30 days preceding the receipt of the challenge inoculum, or planned use during the active study period. Use of any medication known to affect the immune function (e.g., corticosteroids) within 30 days preceding receipt of the challenge inoculum or planned use during the active study period. (Topical and intra-articular steroids will not exclude subjects). MANAGEMENT
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Robin McKenzie, M.D.
Organizational Affiliation
Johns Hopkins Bloomberg School of Public Health
Official's Role
Principal Investigator
Facility Information:
Facility Name
Center for Immunization Research - Johns Hopkins Bloomberg School of Public Health
City
Baltimore
State/Province
Maryland
ZIP/Postal Code
21205
Country
United States
Facility Name
General Clinical Research Center of the Johns Hopkins Hospital
City
Baltimore
State/Province
Maryland
ZIP/Postal Code
21287
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No

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Dose-Finding Study of CS19 Expressing ETEC Challenge Strains

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