ACE BioSciences Begins Landmark Phase IIb Proof of Concept Study with its Travellers' Diarrhoea Vaccine, ACE393

ACE BioSciences, the company that develops vaccines to fight serious bacterial infections, has begun a landmark Phase IIb Proof of Concept study with ACE393, the world's first commercial Campylobacter Travellers' Diarrhoea (TD) vaccine. An interim analysis of the primary outcome will be complete by March 2009 at which point ACE BioSciences should be in a strong position to partner the project.

Ingelise Saunders, ACE BioSciences CEO, commented: 'This is a milestone for ACE BioSciences and in the fight against Campylobacter infection. ACE BioSciences has worked with the US Naval Medical Research Center (NMRC) to establish the first Campylobacter challenge model that satisfies the US FDA’s current safety requirements. The ability to evaluate our vaccine safely gives us clear competitive advantage and we are confident that ACE393 will be the first commercial vaccine to combat this common and debilitating bacterial disease. We estimate that the annual global commercial market for a Campylobacter vaccine is worth € 350 million and the military market represents a further significant opportunity.'

During the trial 40 subjects will receive the vaccine as two injections administered three weeks apart. A further twenty subjects will receive placebo injections. Three weeks after vaccination, subjects will be admitted to hospital and challenged with Campylobacter by drinking a suspension containing 100,000 bacteria. They will then be closely monitored for symptoms, which should develop within 48 hours. The extent of protection from moderate to severe diarrhoea will be evaluated as the end point for efficacy.

Any patient who experiences diarrhoea will receive antibiotic treatment and only be allowed home when the infection has successfully been addressed. Patients will be monitored for four weeks and then followed up at three and six months post-trial. The study is being managed by ACE BioSciences. It is being undertaken at the SNBL Clinical Research Centre, Baltimore, Maryland, US under the auspices of Dr Al-Ibrahim as Principal Investigator and with the support of the Johns Hopkins University and the University of Vermont, which are providing immunology and microbiology input.

The Campylobacter jejuni bacterium is one of the main causes of travellers' diarrhoea and it is responsible for significant disruption to many international travellers and military operations. Many strains of Campylobacter are associated with development of Guillain Barré Syndrome (GBS), a post-infectious polyneuropathy and infection also results in reactive arthritis in a few patients. As a result it has been difficult to develop a safe challenge model for new vaccine evaluation. Until now this has proved a barrier to vaccine development. Antibiotics are frequently prescribed to treat infection and anti-diarrhoeal agents are used to treat symptoms. However, progressive development of antibiotic resistance has limited management options, further emphasising the need for primary prevention.