Clinical Trial: Challenge Study of an ETEC Vaccine

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: A Phase 2b Controlled Efficacy Study of Intradermally Delivered ETEC Fimbrial Tip Adhesin Vaccine Against Experimental Challenge With ETEC H10407 in Healthy Adult Volunteers

Brief Summary: The purpose of the study is to determine the efficacy of a vaccine against enterotoxigenic E. coli (ETEC)-caused diarrhea.

Detailed Summary: The purpose of the study is to establish preliminary efficacy of dscCfaE administered with LTR192G by intradermal (ID) immunization in prevention of disease caused by a challenge with a CFA/I expressing ETEC strain (H10407).
Sponsor: U.S. Army Medical Research and Materiel Command

Current Primary Outcome:

  • Number of adverse events associated with vaccine [ Time Frame: Up to 1 year ]
  • Number of prevented diarrhea episodes [ Time Frame: 24 hours ]


Original Primary Outcome:

  • Number of adverse events associated with vaccine [ Time Frame: Study Day 0-365 ]
    Occurrence of subjective fever, malaise, headache, rash, pain, diarrhea, abdominal pain, extremity pain or swelling reported by in-person symptom surveillance, symptom memory aid tool and clinical assessments.
  • Efficacy of vaccine [ Time Frame: Study Day 70-75 ]

    Prevention of moderate to severe diarrhea:

    • Severe diarrhea: ≥ 6 grade 3-5 stools in 24 hours, or > 800 g of grade 3-5 stools in 24 hours
    • Moderate diarrhea: 4-5 grade 3-5 stools in 24 hours or 401-800 g of grade 3-5 stools in 24 hours.
  • Seroconversion to dscCfaE and LT [ Time Frame: Study Day 0, 21, 42, 69 & 98 ]
    Defined as a > 4-fold increase in endpoint titer for anti-CfaE and Anti-LT IgG and IgA
  • Positive Antibody Secreting Cell (ASC) response [ Time Frame: Study Day 0, 7, 28, 49, 69 & 77 ]
    Defined as a >2-fold increase over the baseline value of the ASC per 10^6 PBMC


Current Secondary Outcome:

Original Secondary Outcome:

Information By: U.S. Army Medical Research and Materiel Command

Dates:
Date Received: August 12, 2013
Date Started: September 19, 2013
Date Completion: June 2017
Last Updated: March 28, 2017
Last Verified: March 2017