Biovector Therapeutics Initiates Feasibility Studies With Chiron and Bayer Corp. On DNA Delivery.

TOULOUSE, France--(BW HealthWire)--March 16, 1999--

Company Signs Additional Agreements With Internationally Renowned

Research Laboratories

BIOVECTOR THERAPEUTICS SA, a privately held company, specializing in delivery systems for biotechnology products, today announced that the Company has signed feasibility agreements with both Chiron and Bayer Corp. These studies are designed to assess Biovector Therapeutics proprietary DNA delivery technology platforms as concerns DNA vaccine and expression of blood circulating proteins.

The agreement with Chiron centers on the use of Neutraplex(TM) Biovector System in novel DNA-based vaccines and covers an initial period of 12-15 months. The objective of the Bayer study is to assess the ability of the Lipoplex-Biovector Systems to allow functional circulating protein expression (Factor VIII). Our goal is to obtain long lasting expression at rates sufficient enough to envisage the development of new treatments for hemophiliae. This study should last 6 months.

"In addition to these feasibility studies, we are funding our own research programs on DNA delivery at renowned academic laboratories, which could lead to exclusive licenses and enlargement of our product portfolio", said Emile Loria, MD, President & CEO of Biovector Therapeutics. "We would like Biovector Therapeutics to be a major player in the drug delivery of biotechnology compounds, among which DNA delivery is key for the future development of medicine. Our feasibility studies currently underway with major pharmaceutical companies and our collaborations with high level academic laboratories are crucial steps to strengthen our position in this area."

BIOVECTOR THERAPEUTICS is also working on the development of a flu DNA vaccine in collaboration with the laboratory of Prof. Karin Molling at the University of Zurich, Switzerland. In the infectious disease area, Biovector established another collaboration with the Institute of Human Virology at the University of Maryland in Baltimore, Maryland directed by Dr. Robert C. Gallo. The objective of this study is to develop an HIV DNA vaccine formulated with the Lipoplex-Biovector System. The Company expects to obtain a highly reproducible and efficient in vivo delivery system that is safe, easily manufactured, and highly standardized. Cellular and molecular immunology of HIV-1 is a major area of expertise of Dr. Gallo's institute.

BIOVECTOR THERAPEUTICS also established a collaboration with the Department of Human Genetics, at the University of Michigan (Ann Harbor, Michigan) headed by Prof. Kotoku Kurachi. This collaboration allows Biovector Therapeutics access to a large number of plasmid constructions corresponding to circulating proteins (Factor IX). The design of these new plasmid vectors is oriented towards the development of systems that would allow long lasting expression of proteins.

The Lipoplex-Biovector Systems developed or licensed by BIOVECTOR THERAPEUTICS are formed by combining lipids and plasmid DNA. The resulting Biovector system has an organizational structure similar to a virus. BIOVECTOR THERAPEUTICS has accumulated specific know-how in formulating these synthetic vectors and has available two Lipoplex-Biovector systems: the DLS System (licensed from National Institutes of Health) and the Neutraplex(tm) System. These patented vectors, developed or licensed by BIOVECTOR THERAPEUTICS, can simply be administered by intramuscular or intravenous injection and can freely circulate within the organism.

Biovector Therapeutics SA is a private French company that has developed unique and proprietary technologies for delivery of biological products called Biovector systems. These Biovector systems are synthetic particles with unique supramolecular structures that have been designed to improve the efficacy of biotech products. The company is mainly focusing on the treatment of infectious diseases and cancer by a curative or prophylactic immunotherapy approach. Biovector Therapeutics concentrates its efforts in the development of modern vaccines taking into account all the components for an efficient immune response. In the field of gene therapy, the company dedicates its efforts in the delivery of DNA encoding for antigenic proteins in vaccine applications and blood circulating proteins in case of deficiency.

Statements made in this release may contain forward-looking statements. Various factors could cause actual results to differ materially from those projected in such statements, including those predicting regulatory processes, the amounts of future payments expected under the collaborative agreement and timing and results of clinical trials. Although the Company believes that the forward-looking statements contained herein are reasonable, it can give no assurance that the Company's expectations are correct. All forward-looking statements are expressly qualified in their entirety by the Cautionary Statement.