West Coast Editor

Scientists at Vaxiion Therapeutics Inc., spun out from San Diego State University about seven years ago, came up with a "minicell" delivery system that could be useful in vaccinating children and the elderly, if mouse results prove out in human trials.

Results published Friday in journal Vaccine showed the minicell vaccine, developed in collaboration with SDSU, mimicked the immune response to live pathogens but without any risk of infection in 89 percent of mice. The rodents were treated with a vaccine against the lymphocytic choriomeningitis virus (LCMV).

Minicells are described in the Vaccine paper as "small (100-400 nanometers), quazi-spherical, achromosomal bacterial particles that result from the disruption of the normal bacterial cell cycle."

Kathleen McGuire, Vaxiion's director of research and a professor at SDSU, did not want to hazard a guess regarding how soon the approach could reach human trials. "We just organized a few months ago, and the company is incubating" at SDSU, she said. "We've been working as a basic research group."

McGuire started with the team in 2003, when Vaxiion was "more a concept than a company," she said. "The patents had been filed by Roger Sabbadini [also a professor at SDSU, co-founder and president of Vaxiion], and we published a paper earlier in 2006, using a basic protein antigen to show we could get immune responses" with the minicell approach.

Sabbadini founded Vaxiion with Neil Berkley at SDSU in 2000, and the firm is one of four biotechnology companies to emerge from SDSU's College of Sciences.

Many existing vaccines are live but attenuated, McGuire pointed out, and even attenuated organisms can cause disease in people with compromised immune systems, such as those who have taken immune-suppressing drugs or who have HIV.

Tests of the vaccine against LCMV - often used as a virus model - will not go forward, since the bug is not a major human health problem. (Carried mainly by house mice, LCMV can be passed to humans, but not all become infected, and symptoms are similar to those for influenza, including fever, muscle aches, headache, nausea, and vomiting.) Based on the success of translational work so far, Vaxiion instead is developing a multicomponent vaccine against Salmonella, Shigella and E. coli for use in human trials.

"We're focusing on food-borne Salmonella, because we think it will have a place in the market for travelers," but the Salmonella vaccine has not yet been tried in animals, McGuire said.

When the subject of vaccines comes up, of course, the first indication that comes to mind for many is influenza - a busy space, given the looming threat of bird flu and the history of shortages for the ordinary human strains. Just last week, BioCryst Pharmaceuticals Inc., of Birmingham, Ala., licensed Japanese rights to its antiviral peramivir to Osaka, Japan-based Shionogi & Co., which provided $14 million up front as part of the potential $130 million deal. (See BioWorld Today, March 7, 2007.)

BioCryst earlier this year won a $102.6 million contract from the U.S. Department of Health and Human Services to develop peramivir for seasonal and life-threatening flu, including avian.

"We have only just started thinking about whether we might be able to develop something for influenza," McGuire said, although the company is considering the minicell technology in cancer vaccines and immunotherapy for other conditions. url = "https://s100.copyright.com/servlet/DispatchServlet"; var location = url + "?PublisherName=" + escape( "BioWorld" ) + "&publication=" + escape( "BioWorld Today" ) + "&Install=S" + "&ContentID=" + escape( "42935" ) + "&Author=" + escape( "Randall Osborne" ) + "&PublicationDate=" + escape( "20070313" ) + "&Title=" + escape( "Vaxiion's Minicell' Approach: A New Vaccine Delivery Bid?" ); PopUp = window.open( location, 'Rightslink', 'location=no,toolbar=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=650,height=550'); }//-->