Lexicon Genetics Inc has filed suit for patent infringement against Deltagen Inc. The complaint, filed in U.S. District Court for the District of Delaware, alleges that Deltagen is willfully infringing the claims of United States Patent No. 5,789,215, under which Lexicon holds an exclusive license. In the complaint, Lexicon is seeking unspecified damages from Deltagen, as well as injunctive relief.

United States Patent No. 5,789,215 covers methods of engineering the animal genome using isogenic DNA technology - a technology of critical importance for the efficient commercial-scale production of knockout mice using gene targeting by homologous recombination. Lexicon itself uses this method to produce custom knockout mice in its homologous recombination program. Lexicon has also developed a new, high-throughput knockout mouse technology which it has used to create the OmniBank library of more than 70,000 knockout mouse clones.

"We believe Deltagen's products and services demonstrate broad use and dependence upon isogenic DNA technology,'' said Arthur T. Sands, MD, PhD, Lexicon Genetics' President and Chief Executive Officer. "We intend to enforce our rights under this patent and continue our strategy of building and protecting our substantial intellectual property portfolio in functional genomics.''

American Home Products, DuPont Pharmaceuticals Company and Roche Bioscience have obtained internal-use sublicenses from Lexicon under the isogenic DNA technology patent for the production of knockout mice for drug discovery research. In order to make this important technology widely available to the academic research community, Lexicon is planning to grant free non-commercial, research-use sublicenses to academic and non-profit research institutions.

Lexicon Genetics Incorporated is a leader in defining the functions of genes for drug discovery using large-scale knockout mouse technology. Lexicon has invented high-throughput gene trapping technology to discover thousands of genes and expand its OmniBank library of tens of thousands of knockout mouse clones.