Syntro Corp., Hoechst-Roussel Agri-Vet Co. and HoechstVeterinar GmbH said Wednesday that they have signed a letterof intent to collaborate on the development of cattle and equinevaccines based on Syntro's viral vector technology.

The Hoechst companies will fund the multiyear developmentprogram, which is expected to cost $6 million to $7 million. Thedisease targets haven't been disclosed.

Under the proposed agreement, Syntro (NASDAQ:SYNT) willperform the molecular biology to develop the vaccines, managemost of the clinical trials and manufacture the drugs. It wouldalso receive sales royalties. The Hoechst companies will marketthe vaccines. Whether Syntro will have co-marketing rightshasn't been determined.

Syntro shares lost 13 cents to $5.25 on Wednesday.

The company has ongoing programs using herpes and certainpox virus vectors, which are engineered to deliver viral andbacterial antigens. The Lenexa, Kan., company hasn't said whichvectors it will be using.

Hoechst-Roussel Agri-Vet and Syntro in March 1991announced a similar agreement to develop a family of poultryvaccines based on the herpes vectors. In September, HoechstVeterinar acquired European marketing rights from Syntro toan inactivated gene-deleted cattle vaccine for infectious bovinerhinotracheitis. That vaccine is in the final stages ofdevelopment.

Syntro is in the process of filing for a proposed public offeringof common shares to raise up to $15 million.

-- Karen Bernstein BioWorld Staff

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