Organon and Lexicon Genetics Collaborate to Develop Biotherapeutics Drugs

"This collaboration, in conjunction with the establishment of ournew biotechnology research center in Cambridge, Massachusetts,reinforces the strong commitment at Organon to research anddevelopment and alliances to expand our biopharmaceutical franchiseinto other areas, including immunology," stated David Nicholson,executive vice-president global research at Organon. "Lexicon'sleadership in novel target discovery complements our own biotechnologyresearch and development capabilities and should provide both of ourcompanies with a new generation of drugs."

Organon and Lexicon will initiate the collaboration by selectingup to 300 genes that encode secreted proteins or potential antibodytargets. Lexicon will create and analyze mouse knockouts of each ofthe 300 genes to identify promising human drug targets. Organon andLexicon will jointly select targets for further research anddevelopment and will equally share costs and responsibility forresearch, preclinical and clinical activities. Organon and Lexiconwill together determine how best to commercialize collaborationproducts and will equally benefit from product revenue. Organon willhave principal responsibility for the manufacturing of biotherapeuticproducts resulting from the collaboration for use in clinical trialsand for worldwide sales.

Lexicon will provide two of its advanced drug discovery programsfor inclusion in the collaboration. Lexicon will receive an upfrontpayment of $22.5 million from Organon in exchange for access toLexicon's drug target discovery capabilities and the exclusive rightto co-develop biotherapeutic products that modulate the 300 genesselected for the collaboration, including the two existing drugdiscovery programs. Organon will also provide annual research fundingtotaling up to $50 million to Lexicon for Organon's 50% share of thecollaboration's costs during the four-year target function discoveryportion of the alliance.

"Our companies will gain a strategic advantage by combiningLexicon's powerful target discovery engine with Organon's drugdevelopment and commercialization experience and manufacturingcapability to move rapidly from gene function discovery to marketedtherapeutic products," said Arthur T. Sands, M.D., Ph.D., presidentand chief executive officer of Lexicon. "We expect a robust pipelineof new antibody drugs and protein therapeutics to result from thecombined efforts of our discovery and development teams."

About Organon

Organon - with shared head offices in Roseland, New Jersey, U.S.A.and Oss, The Netherlands - creates, manufactures and marketsprescription medicines that improve the health and quality of humanlife. Through a combination of independent growth and businesspartnerships, Organon strives to remain or become one of the leadingpharmaceutical companies in each of its core therapeutic fields:reproductive medicine, psychiatry and anesthesia. Organon products aresold in over 100 countries, of which more than 60 have an Organonsubsidiary. Organon is the human health care business unit of AkzoNobel. Additional information about Organon is available through itscorporate website, www.organon.com.

About Lexicon Genetics

Lexicon Genetics is a biopharmaceutical company focused ondiscovering and developing new ways to treat human disease. Lexicon issystematically discovering the physiological and behavioral functionsof genes to identify potential points of therapeutic intervention, ordrug targets. Using its proprietary gene knockout technology, Lexiconhas advanced more than 60 validated small molecule and biotherapeutictargets into drug discovery programs in six therapeutic areas. Lexiconis working both independently and through strategic collaborations andalliances to accelerate the development and commercialization of itsdiscoveries. Additional information about Lexicon is available throughits corporate website, www.lexicon-genetics.com. Organon Safe Harbor Statement*

This press release may contain statements which address such keyissues as Akzo Nobel's growth strategy, future financial results,market positions, product development, pharmaceutical products in thepipeline, and product approvals. Such statements, including but notlimited to the "Outlook", should be carefully considered and it shouldbe understood that many factors could cause forecasted and actualresults to differ from these statements. These factors include, butare not limited to, price fluctuations, currency fluctuations,developments in raw material and personnel costs, pensions, physicaland environmental risks, legal issues, and legislative, fiscal, andother regulatory measures. These factors also include changes inregulations or interpretations related to the implementation andreporting under IFRS, decisions to apply a different option ofpresentation permitted by IFRS, and various other factors related tothe implementation of IFRS, including the implementation of IAS 32 and39 for financial instruments. Stated competitive positions are basedon management estimates supported by information provided byspecialized external agencies. For a more complete discussion of therisk factors affecting our business please refer to our Annual Reporton Form 20-F filed with the United States Securities and ExchangeCommission, a copy of which can be found on the Company's website.

* Pursuant to the U.S. Private Securities Litigation Reform Act1995.

Lexicon Genetics Safe Harbor Statement

This press release contains "forward-looking statements,"including statements about Lexicon's growth and future operatingresults, discovery and development of products, strategic alliancesand intellectual property, as well as other matters that are nothistorical facts or information. These forward-looking statements arebased on management's current assumptions and expectations and involverisks, uncertainties and other important factors, specificallyincluding those relating to Lexicon's ability to successfully conductpreclinical development of its drug candidates and advance suchcandidates into clinical development, achieve its operationalobjectives, obtain patent protection for its discoveries and establishstrategic alliances, as well as those relating to manufacturing, theregulatory process, intellectual property rights, and the therapeuticor commercial value of its drug candidates, that may cause Lexicon'sactual results to be materially different from any future resultsexpressed or implied by such forward-looking statements. Informationidentifying such important factors is contained under "FactorsAffecting Forward-Looking Statements" and "Business - Risk Factors" inLexicon's annual report on Form 10-K for the year ended December 31,2004, as filed with the Securities and Exchange Commission. Lexiconundertakes no obligation to update or revise any such forward-lookingstatements, whether as a result of new information, future events orotherwise.