BioWorld International Correspondent

ACE Biosciences A/S raised €11.9 million (US$17.1 million) in a new investment round to fund a Phase II clinical development program of a vaccine to prevent travelers' diarrhea caused by the foodborne bacterial pathogen Campylobacter jejuni.

The Odense, Denmark-based company has raised €42 million since its formation in 2001, CEO Ingelise Saunders told BioWorld International, and it now has sufficient funding to last until the end of 2009. "This is basically our third round with the same three investors," she said. That trio includes Sunstone Capital A/S, BankInvest A/S and Dansk Innovationsinvestering, all of Copenhagen, Denmark.

ACE Biosciences is co-developing the product, called ACE393, with the Enteric Diseases Department at the U.S. Navy Medical Research Center in Silver Spring, Md. "They had a Campylobacter project that failed, so they're putting all their resources into this project because it's closest to market," Saunders said.

ACE393 is a recombinant vaccine based on a Campylobacter surface antigen, which ACE Biosciences identified following an exhaustive screen of 250 such proteins. It is produced in an E. coli background and already has undergone a safety study in human volunteers. "We've seen very impressive immune responses in our Phase I study," Saunders said.

The company has secured agreements with the FDA and with the London-based European Medicines Agency (EMEA) to undertake a Phase IIb challenge trial, which will get under way around mid-2008. "The beauty of that type of study is that you're sure all the subjects have been exposed to Campylobacter," Saunders said.

It currently is engaged in dosing studies to obtain the correct dose for use in the challenge trial. The latter will recruit 60 participants, who will be randomized in a 2:1 ratio. Subjects will receive either two doses of adjuvanted vaccine or placebo. "We expect it to read out very close to Christmas next year," said Saunders. A Phase III field study is penciled in for 2009.

By then, ACE aims to have secured a commercial development partner, although it also aims to retain European marketing rights for the product. Commercialization of the product would be "quite manageable", Saunders said, as it would be sold primarily through travel clinics.

Campylobacter is the most common cause of food-poisoning in many countries and is the second most frequent cause of travelers' diarrhea, after enterotoxigenic E. coli (ETEC). ACE has an ETEC vaccine development program under way as well, having in-licensed a product called HolaVax - now called ACE527 - from Cambridge, UK-based Cambridge Biostability Ltd. earlier this year. That product already completed five clinical trials, involving more than 100 participants, and a proof-of-concept study is planned for 2009.

Taken together, ETEC and C. jejuni cause about 75 percent of all travelers' diarrhea cases - and there is no licensed vaccine available for either in most major markets, Saunders said.

ACE also is developing a combination product that would provide protection against the two pathogens, although that has yet to enter the clinic. Also in preclinical development are a protein-based Streptococcus pneumoniae vaccine and an antibody targeting the hospital fungal pathogen Aspergillus fumigatus.