PARIS - Biovector Therapeutics, of Toulouse, is preparing to embark on Phase III trials of its nasal influenza vaccine, developed in conjunction with the Canadian company BioChem Pharma Inc., following a second successful Phase I clinical trial.

The trivalent vaccine consists of inactive flu virus antigens administered nasally using the Biovector-Light delivery system. As well as being more pleasant for the patient, the use of a nasal spray enhances the efficacy of the vaccine by triggering the production of antibodies at the nasal mucus level as well as at a systemic level.

An initial Phase I trial carried out in Canada was completed in October 1998, yielding positive results that Biovector regarded as a validation of its delivery system. It was the successful results of this first trial that led to the signing of a worldwide development, production and marketing agreement for the vaccine with SmithKline Beecham, of London, in December 1998.

According to Biovector, the second trial "demonstrated very good tolerance and a satisfactory immunological response, thus meeting the conditions of European directives governing the annual certification of influenza vaccines.'' On the strength of these results, the company has decided to develop a nasal vaccine using antigens cultured on eggs, describing it as "an opportunity with very little risk and a short development time.'' It is in the process of obtaining the doses of vaccine it will require for the Phase III trial, which is to be conducted in Europe.

The nasal spray is one of several novel drug delivery systems developed by Biovector, four of which it has patented for the delivery of various antigens and genes. The main pathologies it is targeting are cancer and certain infectious diseases.