Biovector Therapeutics Appoints Georges Hibon to Board of Directors.

TOULOUSE, France--(BUSINESS WIRE)--June 8, 1999--

Biovector Therapeutics SA, a private company focused on drug delivery systems targeting modern vaccines and gene delivery, today announced the appointment of Georges Hibon to the Company's Board of Directors, effective immediately.

Mr. Hibon was the President & Chief Executive Officer of Pasteur Merieux Connaught of North America from 1990 to 1998 and Chairman of Virogenetics, a joint venture between Pasteur Merieux Connaught and the State of New York. He continues to be on the Board of Pasteur Merieux Connaught North America. Georges Hibon started his pharmaceutical career in 1968 at Merck & Co. (NYSE: MRK) where he held different positions until 1986, including President of the French subsidiary and Vice President of Northern Europe. He has significant experience in developing and launching vaccines and has been instrumental in developing the Pasteur Merieux Connaught Cancer Initiative.

"Biovector is pleased to welcome Mr. Hibon to our Board of Directors. We feel fortunate to be able to draw on his invaluable experience in the vaccine marketplace," stated Emile Loria, President & Chief Executive Officer of Biovector Therapeutics. "His role will be to strengthen Biovector Therapeutics' strategy in the development of our vaccine programs."

Since February 1998, Mr. Hibon has also been an advisor to several companies and organizations in Europe, North America and Asia.

Biovector Therapeutics is a development-stage company that develops and manufactures drug delivery systems to improve the acceptance, delivery and efficacy of modern vaccines and other therapeutic agents. The company's Biovector technology prolongs the effects of therapeutic products, holds patent-extension opportunities for pharmaceuticals and offers a more convenient form of administering drugs. The company mainly focuses 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 to 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.