Taconic Acquires 80% Stake in Artemis

Germantown, New York and Cologne, Germany — November 27, 2007 - Taconic Farms, Inc. (Germantown, NY, USA) today announced that it has reached an agreement to buy an 80.1% stake in Artemis Pharmaceuticals GmbH from Artemis' parent company Exelixis, Inc., South San Francisco (Nasdaq:EXEL). Artemis Pharmaceuticals GmbH will change its name to TaconicArtemis GmbH immediately.

In 2005, Artemis and Taconic established a strategic alliance which combined Artemis' leading technology platform in mouse genetics and genomics with Taconic's industry leading expertise in breeding mice and rats, quality control and global marketing and distribution. The alliance focused on improving access to sophisticated and innovative genetically engineered mice on behalf of investigators in the pharmaceutical, biotech and academic sectors.

Based in Cologne, Germany, Artemis is a world leader in the research, development and commercialization of genetically engineered mouse models (GEMMs) and engineered mouse embryonic stem cells, which are used at various stages of the drug discovery process or in academic research. Taconic is a leading provider of licensing, breeding, and distribution of genetically modified models helping researchers worldwide gain easier access to the unique mouse models that are vital to their drug discovery efforts. Fully integrating Artemis and Taconic will result in a unique organization which leverages the combined assets and resources of each company. In turn, clients will enjoy improved speed of delivery of custom GEMMs utilizing the most advanced gene manipulation and breeding techniques.

"Taconic is delighted to become the majority shareholder in Artemis while retaining Exelixis as minority shareholder," said Sam Phelan, Taconic CEO. "We have already proven that combining the strengths of Artemis and Taconic under the alliance significantly speeds up the delivery of genetically modified mice to clients. The acquisition will enable us to continue to improve this service by more closely aligning our sales, marketing and production operations. The alliance will also benefit from the continued involvement of Exelixis as a shareholder and member of the Taconic Artemis GmbH governing body. Our companies know how to work together and utilize our respective talents and expertise's to design and deliver the critical mouse models needed by researchers to conquer human diseases."

"I believe that the alliance between Taconic and Artemis over the past couple of years has demonstrated the value of combining the two companies' capabilities," said George A. Scangos, Ph.D., president and chief executive officer of Exelixis. "Artemis has established a leading position in the generation of sophisticated mouse models. Taconic is one of the world's leading suppliers of mice. Artemis' capabilities will allow Taconic to provide a broader line of mice to its customers, and to rapidly generate custom-made models for its customers as well. By combining the two companies, the synergies that we already have realized will be significantly enhanced."

"All of us at Artemis are highly pleased about the integration of our company with Taconic, which we consider the ideal partner for us. We had a number of very successful and pleasant years with Exelixis during which we experienced great commercial and scientific successes. Now we are convinced that this present transaction represents a very significant step forward towards an even more successful future of the company," said Dr. Peter Stadler, CEO of Artemis.

About Taconic
Taconic Farms, Inc. was founded in 1952 as a family-owned business in New York's Hudson River Valley. Since then, the company has become one of the largest laboratory rodent providers in the world with a reputation for consistently producing high quality, well-defined rats and mice. Taconic's expertise in breeding, barrier systems, genetics and animal health supports researchers focused on drug development using in vivo models. Taconic has six breeding facilities and three service laboratories in the USA and Europe, a staff of over 800, and a commitment to technological innovation.

About Artemis
Artemis Pharmaceuticals has developed the most versatile technology platform in mouse genetics and -functional genomics. The company offers custom made genetically engineered mouse models and mouse embryonic stem cells for use at various stages of the drug discovery process or in academic research. Models produced include knock out and "humanization" platforms, as well as inducible/reversible RNAi knock down models, and ASKA models for the inducible and reversible knock down of kinases. These platforms are being continually expanded, most recently with the addition of mouse models humanized for key drug metabolism enzymes (ADME mice). Artemis customers include most of the leading pharmaceutical companies, biotech firms and many academic institutions in Europe, the United States and Japan. Artemis is wholly owned by Exelixis, since 2001.

About Exelixis
Exelixis, Inc. is a development-stage biotechnology company dedicated to the discovery and development of novel small molecule therapeutics for the treatment of cancer and other serious diseases. The company is leveraging its fully integrated drug discovery platform to fuel the growth of its development pipeline, which is primarily focused on cancer. Currently, Exelixis' broad product pipeline includes investigational compounds in phase 2 and phases 1 clinical development for cancer and renal disease. Exelixis has established strategic corporate alliances with major pharmaceutical and biotechnology companies, including GlaxoSmithKline, Bristol-Myers Squibb Company, Genentech, Wyeth Pharmaceuticals and Daiichi-Sankyo. For more information, please visit the company's web site at http://www.exelixis.com.