LONDON - Cambridge Antibody Technology Group plc entered its largest deal to date, with G.D. Searle & Co., for the development of fully human monoclonal antibody-based drugs across multiple disease areas.

Searle will take a 6.9 percent equity stake in CAT, valued at US$12.5 million. In addition it will fund the research for three years, at a minimum cost of US$14.5 million. CAT said the deal could be worth up to US$150 million in clinical development and regulatory approval milestones.

CAT CEO David Chiswell said, "This alliance signifies an exciting stage in CAT's evolution as a drug development company. This further underscores our commitment to delivering antibodies on an industrialized scale, to add value to the genomics-derived disease targets of the future. The alliance is CAT's largest to date and provides further endorsement by the pharmaceutical industry of the potential for human monoclonal antibodies to fill the product pipeline gap."

The alliance combines CAT's expertise in high-throughput antibody generation with Searle's capabilities in genomics, discovery biology and drug development. Searle, the pharmaceutical arm of Monsanto Co., will supply target proteins, including those derived from its own internal discovery programs, and both companies will perform collaborative research to demonstrate and validate their disease association. As part of the target validation process, CAT, of Royston, Cambridgeshire, will apply its proprietary ProAb technology for high-throughput antibody generation to examine the expression of novel proteins in human tissues.

The two will jointly develop customized assays and CAT will generate human antibody-based drugs directed to the targets. Searle will develop products further and market the drugs.

Searle has the option to extend the collaboration up to five years on similar terms. CAT has also granted Searle multisite options to license, for additional fees, CAT's antibody phage display library technology for use in house. Over the potential five-year term of the research collaboration, CAT could receive a further US$35 million in license fees, research funding and technical performance milestones.

"Searle views CAT as the leader in the field of phage antibodies," said Philip Needleman, co-president of Searle. "We are confident that this technology will deliver therapeutics of the highest quality as well as the tools to enhance all stages of our drug discovery and development pipeline."