Press Release: Lexicon Genetics Changing Name, Refocusing Business to Achieve Goal

Lexicon Genetics Changing Name, Refocusing Business to Achieve Goal of Advancing Ten Drug Candidates Into Human Clinical Trials by 2010 THE WOODLANDS, Texas, January 29, 2007 -- Lexicon Genetics Incorporated announced today that it is changing its name to Lexicon Pharmaceuticals, Inc. to reflect that it is focusing its operations on drug discovery and development activities related to its 10to10 Program. The 10to10 Program is an ongoing company initiative with the goal of advancing ten drug candidates into human clinical trials by 2010. Lexicon's planned name change will be submitted for shareholder approval at its upcoming annual shareholder meeting. Lexicon expects the 10to10 clinical development programs to result from its internal drug discovery efforts as well as from efforts with collaborators. Lexicon has two proprietary compounds in human clinical trials and anticipates filing investigational new drug applications for two additional compounds in 2007. Lexicon's operational realignment has been made possible by the scheduled completion of its Genome5000(TM) program. Lexicon is reducing the financial and human resources applied to its genetic research efforts and will reallocate those resources to its novel drug development programs. As a result, Lexicon expects operating expenses for 2007 to be approximately the same as in 2006, even with a substantial increase in clinical development activity. "We are reaching the successful conclusion of the Genome5000 program and have made the transition to drug development," said Arthur T. Sands, M.D., Ph.D., president and chief executive officer. "With two investigational new drugs already in clinical trials and two more INDs to be filed this year, we believe we are well on our way to achieving our goal of ten drug candidates in human clinical trials by 2010. Our target discovery engine has delivered more than 100 promising drug targets addressing major medical needs. We are now fully aligned to rapidly develop drugs based on our novel targets." Phase 1 clinical trials are ongoing for LX6171, Lexicon's oral drug candidate being developed to treat disorders characterized by cognitive impairment such as Alzheimer's disease, schizophrenia or vascular dementia. In addition, Lexicon recently initiated Phase 1a clinical trials of LX1031, an oral drug candidate being developed for irritable bowel syndrome and other gastrointestinal disorders. In the second half of 2007, Lexicon expects to file IND applications for LX2931 for rheumatoid arthritis and LX1032 for gastrointestinal disorders. About Lexicon Lexicon is a biopharmaceutical company discovering and developing breakthrough treatments for human disease. Lexicon currently has clinical programs underway for such areas of major unmet medical need as irritable bowel syndrome and cognitive disorders. The company has used its proprietary gene knockout technology to discover more than 100 promising drug targets and create an extensive pipeline of clinical and preclinical programs in the therapeutic areas of diabetes and obesity, cardiovascular disease, psychiatric and neurological disorders, cancer, immune system disorders and ophthalmic disease. To advance the development and commercialization of its programs, Lexicon is working both independently and through collaborators which include Genentech, Inc., Bristol-Myers Squibb Company, N.V. Organon and Takeda, Ltd. For additional information about Lexicon and its programs, please visit . Safe Harbor Statement This press release contains "forward-looking statements," including statements relating to Lexicon's plans regarding regulatory filings and clinical development programs for LX6171, LX1031, LX2931 and LX1032 and the potential therapeutic and commercial potential of LX6171, LX1031, LX2931, LX1032 and other potential drug candidates in Lexicon's preclinical pipeline. This press release also contains forward-looking statements relating to Lexicon's growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. All forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Lexicon's ability to successfully conduct clinical development of LX6171 and LX1031 and preclinical development of LX2931, LX1032 and other potential drug candidates, advance additional candidates into preclinical and clinical development, obtain necessary regulatory approvals, achieve its operational objectives, obtain patent protection for its discoveries and establish strategic alliances, as well as additional factors relating to manufacturing, intellectual property rights, and the therapeutic or commercial value of its drug candidates, that may cause Lexicon's actual results to be materially different from any future results expressed or implied by such forward-looking statements. Information identifying such important factors is contained under "Factors Affecting Forward-Looking Statements" and "Business - Risk Factors" in Lexicon's annual report on Form 10-K for the year ended December 31, 2005, as filed with the Securities and Exchange Commission. Lexicon undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise. CONTACT: Bobbie Faulkner, Manager, Investor Relations of Lexicon GeneticsIncorporated, +1-281-863-3503, or ; or Aline Schimmelof WeissComm Partners, +1-212-301-7218, or , for Lexicon Genetics Incorporated [email protected] [email protected]