Juvaris BioTherapeutics Announces Effectiveness of the JuvImmune Immunostimulant
for AntiViral Applications


Juvaris Immunostimulant Demonstrates Complete Efficacy for PuntaToro Virus Infection in a Prophylactic and Therapeutic Rodent Model

Pleasanton, CA - April 12, 2005

Juvaris BioTherapeutics, Inc. announced today the completion of the initial preclinical evaluation for the efficacy of the JuvImmuneTM immunostimulant platform in a mouse model of PuntaToro virus infection. This research was conducted at the Institute for Antiviral Research of Utah State University and funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

PuntaToro virus (PTV), which produces a fatal hepatic disease in animals, is closely related to the African and Middle Eastern Rift Valley Fever and Sandfly Fever viruses. These viral infections have had devastating effects in many parts of the world and are now considered significant biodefense concerns to the United States. Results of these studies were presented last week at the Federation of American Societies for Experimental Biology (FASEB) meeting in San Diego, California.

Juvaris' JuvImmuneTM technology was found to be highly active against PTV infection and exhibited rapid activation of the innate immune response for the production of anti-viral interferons as well as interleukins. JuvImmuneTM treatment was well-tolerated and demonstrated complete protection in both prophylactic and therapeutic applications. Other observations included increased survival time, reduction of virus-induced liver damage, and decreased virus titers.

Innate immune activation is the first-line of defense against viral agents and is critical for induction of subsequent specific immune responses. Preclinical studies, using JuvImmuneTM in other viral and bacterial infection models, have also demonstrated substantial amplification of immune responses and protection. JuvImmuneTM testing is now being extended for evaluation in additional viral studies including Respiratory Syncytial Virus (RSV) and Hepatitis B virus (HBV).

"We are pleased with these dramatic efficacy results and the external validation they provide for the JuvImmuneTM technology. We believe our platform has significant broad-based product applicability in both chronic and acute viral infections, including biodefense pathogens" said Martin D. Cleary, Co-founder, Chairman and CEO of Juvaris.

About Juvaris

Juvaris BioTherapeutics was created in 2002 to develop an immunotherapeutic product platform for the treatment of infectious diseases and cancer using lipid-DNA complexes. Cationic lipids are formulated with non-coding DNA (plasmid) to create JuvImmuneTM, a single lipid-DNA complex, which as an immunostimulation product will have utility in a number of non-antigen immunotherapeutic applications. The DNA in these complexes does not code for protein, but rather, through a combined synergistic effect with lipids, strongly stimulates immune responses. The JuvImmuneTM product has been shown to be at least 50-times more potent at triggering innate immune activation and interferon release than current immune stimulants. Juvaris was recently issued Patent No. 6,693,086 titled "Systemic Immune Activation Method Using Nucleic Acid-Lipid Complexes" providing broad intellectual property coverage for the JuvImmuneTM technology.

When combined with disease-specific antigens, the technology creates JuvaVaxTM vaccines capable of activating substantial antibody- and cell-mediated immune responses, particularly induction of cytotoxic T lymphocytes. Immunological responses elicited by the lipid-DNA complexes have been successfully demonstrated in both prophylactic and therapeutic settings in a variety of mammals including rodents, rabbits, cats, dogs and non-human primates. Moreover, substantial immune responses have been induced following oral administration. This system provides the opportunity to develop many disease-specific vaccine products, for which there are significant unmet medical needs.

Over the past nine months, the Company has announced collaborations or investigational studies with Cell Genesys, SomaGenics, the University of California-San Francisco, Penn State University, the Defense Advanced Research Projects Agency (DARPA), the National Institutes of Health (NIH), the Institute for Antiviral Research at Utah State University, and the International AIDS Vaccine Initiative (IAVI).

The Company encourages investment and partnering inquiries and can be reached at its website @ www.juvaris.com.

Company Contact:
Grant E. Pickering
Juvaris BioTherapeutics, Inc.
863A Mitten Road
Burlingame, California
650-259-1800 ext. 227
gpickering@juvaris.com