Two oral presentations, two poster discussion presentations, three poster presentations

SOUTH SAN FRANCISCO, Calif., March 31 /PRNewswire-FirstCall/ -- Exelixis, Inc. (Nasdaq: EXEL) announced today that data from clinical trials of the company's investigational compounds XL647, XL184, XL765 and XL880 will be presented at the 2008 American Society of Clinical Oncology (ASCO) Annual Meeting, which will be held from May 30 to June 3, 2008 in Chicago, Illinois. The clinical trial data will be described in two oral presentations (XL184 and XL765), two poster presentations and discussions (XL647), and three poster presentations (XL647 and XL880).

Oral Presentations

• XL184 (RET, MET, VEGFR2). Data from a phase 1 trial of XL184 in patients with advanced malignancies, including medullary thyroid cancer, will be presented on Sunday, June 1, 2008, starting at 10 a.m. local time (Abstract #3522).
• XL765 (PI3K, mTOR). Data from a phase 1 trial of XL765 in patients with advanced solid tumors will be presented on Saturday, May 31, 2008, starting at 1:15 p.m. local time (Abstract #3510).

Poster Presentations and Discussions

• XL647 (EGFR, HER2, VEGFR2). Data from a phase 2 trial of XL647 in NSCLC patients with acquired resistance to EGFR tyrosine kinase inhibitors will be presented on Monday, June 2, 2008, during the 8 a.m.-noon session (Abstract #8028).
• XL647 (EGFR, HER2, VEGFR2). Data from a phase 1 trial of XL647 dosed daily in patients with advanced solid malignancies will be presented on Saturday, May 31, 2008, during the 8 a.m.-noon session (Abstract #3528).

Poster Presentations

• XL647 (EGFR, HER2, VEGFR2). Data from a phase 2 trial of XL647 in clinically selected NSCLC patients enriched for the presence of EGFR mutations will be presented on Sunday, June 1, 2008, during the 2-6 p.m. session (Abstract #8053).
• XL880* (MET, VEGFR2). Data from a phase 2 trial of XL880 in patients with papillary renal cell carcinoma will be presented on Saturday, May 31, 2008, during the 8 a.m.-noon session (Abstract #5103).
• XL880* (MET, VEGFR2). Data from a phase 2 trial of XL880 in MET amplified, poorly differentiated gastric cancer will be presented on Monday, June 2, 2008, during the 8 a.m.-2 p.m. session (Abstract #4572).

* XL880 was selected by GlaxoSmithKline in December 2007 for further development and commercialization.

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 phase 1 clinical development. 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.

Exelixis and the Exelixis logo are registered U.S. trademarks.

SOURCE Exelixis, Inc.
CONTACT: Charles Butler, Senior Director, Corporate Communications &
Investor Relations, +1-650-837-7277, cbutler@exelixis.com, or Soleil Harrison,
Senior Manager, Corporate Communications, +1-650-837-7012,
sharriso@exelixis.com, both of Exelixis, Inc.
Web site: http://www.exelixis.com