Clinical Trial: Safety Study of Chimeric Vaccine to Prevent ETEC Diarrhea

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

Official Title: A Phase 1 Dose Escalating Study of Two Enterotoxigenic Escherichia Coli Prototype Adhesin-based Vaccines With or Without Modified Heat-labile Enterotoxin by Intradermal or Transcutaneous Immunization

Brief Summary: The purpose of the study is to determine if immunization with a chimeric E. coli protein, dsc14CfaE-sCT2/LTB5, is safe and immunogenic when administered by vaccination under the skin.

Detailed Summary: The purpose of the study is to evaluate the safety and immunogenicity of dsc14cfaEsCTA2/LTB5 (Chimera) and dscCfaE administered with and without LTR192G by intradermal (ID) immunization and to gather additional data on the administration of dsCfaE and LTR192G via transcutaneous immunization (TCI) route. If vaccines are found to be safe and adequately immunogenic in humans, a down-selection would occur and a phase 2b vaccination/challenge study would be undertaken to further evaluate vaccine safety and allow a preliminary assessment of efficacy of one of these candidates by the ID or TCI route. With favorable evidence for safety, immunogenicity, efficacy, complemented by advances in standard methodology to combine multiple adhesins with an appropriate LT enterotoxoid form, a multivalent vaccine would be constructed and evaluated for further clinical development.
Sponsor: U.S. Army Medical Research and Materiel Command

Current Primary Outcome:

  • Number of Adverse Events [ Time Frame: 1 year ]
  • Number of seroconversion events [ Time Frame: day 0, 21, 42, 56, 70 ]
    The primary immunology outcome is seroconversion to LT and dscCfaE will be defined as a > 4-fold increase in endpoint titer between pre-and post-vaccination samples


Original Primary Outcome: Safety Based on Number of Adverse Events [ Time Frame: Study Days 0 -180 ]

Safety and tolerability as measured by occurrance of local and systemic adverse events following receipt of the investigational products


Current Secondary Outcome: Number of positive IgA-ASC response [ Time Frame: Day 0, 21,42, 56, 70 ]

A positive IgA-ASC response will be defined as a > 2-fold increase over the baseline value of the ASC per 106 PBMC, when the number of ASC is > 0.5 per 106 in the baseline sample.


Original Secondary Outcome: Immunogenicity Based on Serum and Mucosal Responses [ Time Frame: Study Days 0 - 70 ]

Development of systemic and mucosal immune responses as measured by serum and fecal antibody titers to the immunizing antigens as well as vaccine-specific antibody secreting cells.


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

Dates:
Date Received: July 11, 2012
Date Started: August 2012
Date Completion: November 2017
Last Updated: October 30, 2015
Last Verified: October 2015