Biovector Therapeutics Announces Successful Phase I Clinical Trial Results for the Novel Nasally-Delivered Influenza Vaccine.

TOULOUSE, France--(BW HealthWire)--Oct. 28, 1998--Biovector Therapeutics SA, a privately held company, specializing in drug delivery systems, today announced positive Phase I results for the novel influenza vaccine designed for nasal administration.

This new vaccine is being co-developed by Biovector Therapeutics and BioChem Vaccines, a BioChem Pharma subsidiary. The vaccine incorporates inactivated influenza antigens with licensed Biovector's proprietary delivery technology (SMBV(R)/Light-Biovector System), which enables the vaccine to be administered using a nasal spray rather than via parenteral injection.

The Phase I study was designed to prove that nasal administration of a trivalent influenza vaccine, using this Biovector System for nasal delivery, could be safe and immunogenic. The study endpoints were achieved as measured by the safety profile and significant increases in systemic IgG and in mucosal IgA.

Since the nasal air passage is the route of transmission for influenza, a vaccine given by this route may elicit nasal mucosal antibody production, in addition to systemic immunity, and thus may afford better protection against infection. Nasal administration of this novel influenza vaccine has shown to provide a safe and more complete immunogenicity profile.

"These first results are very encouraging and we consider them as a validation of our Light-Biovector drug delivery system, designed for mucosal administration of various vaccine candidates," said Dr. Loria, President & CEO of Biovector Therapeutics. "This study was conducted using egg-cultured antigens. Other clinical studies are planned using BioChem Pharma's cell culture antigens that could help both companies to set up new standard of flu vaccine".

This Phase I study was carried out at the Clinical Trials Research Center at Dalhousie University IWK-Grace Health Care Center in Halifax, Nova Scotia (Canada), with Dr. Scott A. Halperin, M.D., as principal Investigator.

This randomized, double blind, placebo control Phase I study was conducted in 60 healthy adult subjects. Using three different dose levels and placebo, the primary objective was to assess the safety of the vaccine while the secondary objective was to evaluate local and systemic immune response (immunogenicity) to the nasal vaccine. The subjects were randomly divided into four groups, the first three groups received the new nasally-delivered vaccine at different doses and the fourth, a saline solution as placebo. The vaccination contained the three viral strains recommended by the World Health Organization for the 1997-98 influenza season, formulated with the Light-Biovector delivery system, and was administered in two doses, 28 days apart, outside the regular influenza season.

A mean rise of 4-fold or greater in mucosal IgA titre was observed for all of the three strains. A significant rise in systemic IgG by as much as 4-fold or greater in one of the treatment arms was observed even after the first dose administration in study volunteers with a low influenza immune status prior to vaccination as measured at study entry. The nasal vaccine was safe and well tolerated in all groups after administration of each of the doses.

BioChem's new nasally delivered influenza vaccine has been formulated using the Light-Biovector System developed by Biovector Therapeutics SA. The latter licensed out to BioChem Pharma the exclusive right to use, develop and commercialize this technology for flu vaccine and certain of its bacterial vaccine applications.

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.

This press release contains forward-looking statements that reflect the Company's current expectation regarding future events. The forward-looking statements involve risks and uncertainties. Actual events could differ materially from those projected herein and depend on a number of factors including the success of the Company's research strategy, the applicability of the discoveries made therein, the successful and timely completion of clinical studies, the uncertainties related to the regulatory approval process, the discovery and development of new drugs or vaccines, and what the development of the knowledge of the human body will tell us.