Globally integrated biopharmaceutical company Immuron Ltd (NASDAQ:IMRN, ASX:IMC) says the US Naval Medical Research Command (NMRC) has wrapped up interim analysis in a clinical study for a new oral therapeutic targeting Campylobacter and Enterotoxigenic Escherichia coli (ETEC).
New vaccine
The NMRC used US Department of Defense funding to develop a new campylobacter vaccine not conjugated with ETEC, as well as new vaccines for shigella and different strains of E.coli.
A preventative treatment that protects against enteric diseases is a high-priority objective for the US Military.
Immuron’s role in the study was to produce a hyperimmune bovine colostrum product using the NMRC-developed campylobacter/ETEC vaccine which was tested in a controlled human infection model study.
Campylobacter jejuni, or C. jejuni, is an invasive enteric pathogen.
It’s among the most common causes of diarrheal disease globally and yet comparatively little work has been done on developing protective immunity against it and there is no licensed vaccination.
The molecular details of C. jejuni’s pathogenesis remain difficult to interpret or understand largely due to the lack of reliable, non-primate animal models of disease.
To combat the disease C. jejuni causes, the NMRC developed a conjugated vaccine using the Campylobacterjejuni capsule crosslinked to the colonisation factor antigen 1 (CFA/1) of Enterotoxigenic Escherichia coli (ETEC).
Protective against diarrhoea
These key antigenic targets are predicted to be protective against the diarrhoea induced by both pathogens.
Immuron used the conjugated vaccine to produce a new hyperimmune anti-microbial for clinical evaluation by the NMRC.
The NMRC confirmed that the conjugated vaccine produced a robust immunological response in cows.
It also reported that the new Hyper-immune therapeutic contains high levels of antibodies which specifically target Campylobacter jejuni capsule and CFA/1.
Trial details
The safety and protective efficacy of the product was tested in the NMRC’s controlled human infection-model clinical trial, with a focus on the ability of the hyperimmune product to protect volunteers against moderate to severe campylobacteriosis.
A group of 27 volunteers were enrolled in the randomised, placebo-controlled trial and randomly assigned to either the active or placebo arm of the study.
The interim results demonstrated 10.4% protective efficacy against moderate to severe campylobacteriosis following challenge with Campylobacter compared to the placebo group.
The NRMC continues to analyse the data, including secondary and exploratory endpoints, to determine why protective efficacy for CampETEC was lower than that achieved in similar studies with Travelan®.
Immuron is not privy to any further details of the study at this time, pending the presentation of findings described below.
Principal investigator Dr Frédéric Poly will present the study’s findings at the 22nd International Workshop on Campylobacter, Helicobacter and Related Organisms (CHRO 2024) today at the Perth Convention and Exhibition Centre. The company will release the presentation on its website after the event.
Impact on Travelan
The results of the trial are unrelated to Travelan® and have no bearing on Immuron’s plans to hold an end of Phase 2 meeting with the US Food and Drug Administration (FDA) with a view to kicking off Phase 3 clinical trials of the asset in the second half of next year.
Furthermore, the NMRC-funded trial has no impact on Immuron’s commercialisation strategy for Travelan®, which also includes the results of the Uniformed Services University clinical study (n=866) of Travelan® – now 85% recruited with topline results anticipated in April 2025.
Combatting infectious diarrhoea
Travelan® demonstrated clinical efficacy in preventing ETEC-attributable diarrhoea in two previous CHIM studies.
These studies showed dosing 400 mg three times daily, resulted in 76.7% to 90.9% protection, and more recently 36.4% protective efficacy in a single daily dose Phase 2 study designed to compare the preventative effects of once daily dosing to the current standard recommended treatment of three times daily dosing.
This Phase 2 single dose trial also produced clinically relevant secondary endpoints.
The plan is to develop new hyperimmune products which specifically target each of these pathogens in collaboration with Immuron.
Infectious diarrhoea is the most common illness reported by travellers visiting developing countries and among US troops deployed overseas.
The morbidity and associated discomfort stemming from diarrhoea decreases daily performance, affects judgment, decreases morale and declines operational readiness.
The first line of treatment for infectious diarrhoea is the prescription of antibiotics.
Unfortunately, in the last decade, several enteric pathogens have had an increasing resistance to commonly prescribed antibiotics.
Traveller’s diarrhoea is now recognised to result in post-infectious sequelae, including post-infectious irritable bowel syndrome and several post-infectious autoimmune diseases.