By Lisa Seachrist

Washington Editor

Dyax Corp. signed a collaborative study agreement with Merck & Co. for the discovery and evaluation of novel affinity ligands for vaccine purification.

The agreement is the eighth arrangement since January 1997 centered on Dyax's proprietary phage display technology. These collaborations with a number of pharmaceutical and biotechnology companies highlight Dyax's strategy to widely leverage its technology for drug discovery and purification.

"We believe the technology is very powerful," said Steven Bernitz, vice president for business development for the Cambridge, Mass., company. "Our collaborations and licensing agreements indicate that we aren't alone in that assessment. The Merck deal is the first time that we have worked with a company specializing in vaccines."

While Dyax and Merck aren't releasing the financial terms of the agreement, Merck will fund the research conducted at Dyax and will pay milestones and royalties to Dyax should a product result. Bernitz said the terms are quite similar to the other research agreements that Dyax has negotiated.

Dyax's phage display technology combines the advantages of combinatorial chemistry with the diversity and speed of biological systems to develop affinity chromatography separation products to reduce the time required for the introduction of new therapeutic products and to enhance the efficiency of purification of pharmaceuticals and biologics.

The company uses several combinatorial phage libraries. Phages are viruses that infect bacteria, and the company engineers them to express small structure peptides on the outside of the virus. The company then searches for the small peptides that bind most specifically to the target molecule.

"The phage display technology allows us to screen tens to hundreds of millions of compounds quickly to determine which ones have the most efficient binding," Bernitz said. "It also allows us to find the best peptides for binding and releasing at specified conditions. With antibodies, you are limited to physiologic conditions."

Merck, of Whitehouse Station, N.J., is interested in the system as a way to create highly purified vaccines. Traditionally, most vaccines have not been very pure products. Merck is exploring whether purer vaccines produce fewer side effects at the injection site and fewer incidences of fever. At first, the company will test the technology's ability to clean up a single vaccine, but the collaboration could expand to include other vaccines.

In addition, the company plans to enter into several more drug discovery and purification collaborations before the end of the year.

"We are doing some work with a customer that wants to remove antibodies from their purification procedure in order to produce a product that has no animal sources used in its preparation," Bernitz said. "And we are doing some work with another customer to remove a contaminant virus from a product." *