Immuron reports positive results from Travelan testing, develops anti-dysentery vaccine products

Australian biopharmaceutical company Immuron (ASX: IMC) has reported positive results from a study designed to test the efficacy of Travelan anti-dysentery medication on non-human primates.

The placebo-controlled Shigellosis challenge study was conducted by the US Armed Forces Research Institute of Medical Sciences under a co-operative research and development agreement which Immuron has in place with the US Department of Defence.

It was designed to determine the potential of Travelan as a preventative treatment for US military personnel and civilians stationed or travelling in locations around the world where such infections may be debilitating.

Reduced response

The study was carried out on 12 juvenile rhesus monkeys segregated into two groups – a Travelan treatment cohort of eight and a placebo cohort of four – which were treated twice daily for a total of 12 doses over a six-day period.

The results showed that prophylactic administration of Travelan could significantly reduce the inflammatory response in animals with severe infections of the gastrointestinal tract and high-inflammatory cytokines in faecal samples.

Travelan was proven to prevent clinical shigellosis (bacillary dysentery) in 75% of animals in the treatment group compared to the placebo and demonstrated a significant clinical benefit.

All of the placebo-treated animals displayed acute clinical signs of dysentery within 36 hours of the challenge commencing, while only two of the eight Travelan-treated cohorts did the same.

The remaining six of the Travelan-treated group remained healthy and without any signs of dysentery post-challenge.

Placebo results

A recently-completed histopathological analysis by Immuron – which provided a comprehensive view of dysentery and its effect on gut tissue – revealed that all animals in the placebo-treated group displayed severe inflammation in different parts of the gastrointestinal tract.

These animals also had very high levels of inflammatory cytokines in faecal samples collected throughout the study.

The inflammation seen in the gastrointestinal tract and the increase in inflammatory cytokines in the faeces were found to be closely associated with observed clinical outcomes of dysentery.

By comparison, only three of the eight Travelan-treated animals showed signs of inflammation in the gastrointestinal tract, and only two of those had high levels of inflammatory cytokines in faecal samples.

All other animals in the Travelan-treated group were clinically healthy and did not excrete any inflammatory cytokines.

Neutralising infection

Immuron chief executive officer Dr Gary Jacob said the study results confirm that Travelan is functionally cross-reactive and may have some prophylactic activity against Shigellosis.

“[This study has] clearly demonstrated the effectiveness of Travelan and [our] technology platform in neutralising pathogenic gastrointestinal bacterial infections,” he said.

“We believe it offers significant potential for military personnel stationed in areas of the world where dysentery and gut infections are common and debilitating if contracted.”

Vaccine therapies

Immuron has also reported the completion of three new Shigella-specific therapeutic products with proprietary vaccines, developed by the Walter Reed Army Institute of Research (WRAIR) based in Thailand.

WRAIR has been involved in the development of vaccines against Shigella for over a decade.

Immuron said preliminary laboratory evaluation tests indicated all three products could generate a strong antibody response to Shigella antigens used in its manufacturing campaign.

The products will now be evaluated in pre-clinical models of shigellosis, developed and funded by WRAIR.

Highly-purified tablet

Travelan is an orally-administered passive immunotherapy which can reduce the likelihood of a person contracting diarrhea while travelling.

When taken with meals, the highly-purified hyper immune bovine antibodies in each tablet bind to the diarrhea-causing bacteria to prevent colonisation.

In Australia, Travelan is a listed medication on the Australian Register for Therapeutic Goods and is indicated to reduce the risk of traveller’s diarrhea and minor gastro-intestinal disorders.

In Canada, Travelan is a licenced natural health product and in the US, it is sold as a dietary supplement for digestive tract protection.

Complex disease

On a global scale, the number of annual cases of dysentery are believed to outweigh all of the more complex diseases seen in gastroenterology clinics.

Every year, there are an estimated 1.5 billion episodes of diarrhea recorded worldwide and around 2.2 million related deaths, the majority of which are children in developing countries.

A preventative treatment which protects against enteric diseases, specifically shigellosis, is a high priority objective for the US army.

Shigella species are estimated to cause up to 165 million cases of disease worldwide and 600,000 deaths annually.

The disease is particularly prevalent in regions around sub-Saharan Africa and South Asia.

Directors back Immuron

As Travelan continues to produce positive results during testing, Immuron’s directors are scooping up shares in the stock.

Earlier this month, director Daniel Pollock acquired 70,000 shares on-market for $9,538.

Meanwhile, executive vice chairman Peter Anastasiou bought up 500,000 shares in late May for $77,500. Mr Anastasiou’s transaction was also on-market.

At midday, shares in Immuron were up 12% to $0.14.