Immuron Limited has announced the submission of its Clinical Study Report to the U.S. Food and Drug Administration (FDA) for the recently completed Phase 2 clinical trial of Travelan (IMM-124E). The company will soon request an end of Phase 2 meeting, a necessary step before proceeding to Phase 3 trials.
The Phase 2 study (NCT05933525) was a randomized, double-blind, placebo-controlled trial assessing the efficacy of IMM-124E (Travelan) in a controlled human infection model for Enterotoxigenic Escherichia Coli (ETEC).
Immunology Results
The study demonstrated statistically significant lower levels of IgA and IgG in subjects who received Travelan compared to those who received the placebo. This may reflect reduced exposure to ETEC antigen, as Travelan antibodies target and bind to ETEC antigen in the gastrointestinal tract, blocking LPS epitopes and reducing antigen exposure, resulting in lower overall IgA and IgG antibody titers.
Clinical data also showed a statistically significant reduction in the number of colony forming units (CFUs) in the stools of subjects who received Travelan (p = 0.0121), measured 48 hours post-challenge. This indicates a faster clearance of the challenge strain from the GI tract.
Microbiome Analysis
Participants in the Travelan group exhibited a more stable gastrointestinal microbiota over the treatment period compared to the placebo group. Alpha diversity measurements, assessing richness and evenness, revealed that the Travelan group had improved richness and Shannon diversity results.
Statistically significant differences were identified between the two treatment groups in Beta diversity tests. The relative abundance results showed that the Travelan group had increased levels of beneficial bacteria such as Akkermansia and Faecalibacterium. Differential abundance results confirmed increases in Agathobaculum, Slackia, the Eubacterium eligens group, and the Eubacterium siraeum group, and decreases in Rumminococcus and Bacteroides. The abundance data indicates a possible link between the species of bacteria associated with reduced inflammation.
Implications for Traveler's Diarrhea
Traveler's diarrhea (TD) is a common ailment, defined as the passage of three or more unformed stools per 24 hours, accompanied by at least one additional symptom such as nausea, vomiting, abdominal cramps, or fever. It remains a frequent health problem for travelers to resource-limited destinations. Deployed US military personnel are particularly vulnerable. Diarrheagenic E. coli, Campylobacter spp., and Shigella spp. are among the most commonly reported causes.
The study data suggests that Travelan aids in the reduction and clearance of pathological ETEC bacteria, shortening the recovery period after ETEC challenge. The mechanism involves an increase in the propagation of bacteria associated with decreases in inflammation and repairing the intestinal lining. Further investigation is required to fully understand the benefits of Travelan on the gut microbiome.
Uniformed Services University Field Study
In addition to the Phase 2 study, a field study (NCT04605783) at the Uniformed Services University is evaluating Travelan as a dietary supplement to maintain gut health during deployment and travel. To date, 776 subjects have been randomized into this double-blind, placebo-controlled trial, with final enrollments expected in March 2025 and follow-up completed around June 2025.
About Travelan
Travelan is an orally administered passive immunotherapy that reduces the likelihood of contracting travelers’ diarrhea. It is a purified tablet preparation of hyperimmune bovine antibodies that bind to diarrhea-causing bacteria, preventing colonization and associated pathology. In Australia, it is indicated to reduce the risk of Travelers’ Diarrhea and minor gastrointestinal disorders and is antimicrobial. In Canada, it is indicated to reduce the risk of Travelers’ Diarrhea. In the U.S., Travelan is sold as a dietary supplement for digestive tract protection.
