Press Release

Exelixis Announces May 11 Webcast of First Quarter 2010 Financial
Results Conference Call

April 28, 2010

SOUTH SAN FRANCISCO, Calif., Apr 28, 2010 (BUSINESS WIRE) --Exelixis, Inc. (Nasdaq:EXEL) will release its first quarter 2010 financial results on Tuesday, May 11, 2010 after the markets close. The announcement will be followed by a live webcast at 5:00 p.m. ET/ 2:00 p.m. PT, in which Exelixis management will discuss the financial results, financial outlook, and provide a general business update. The webcast may be accessed in the Event Calendar page under Investors at http://www.exelixis.com.

An audio replay of the webcast will be available until 11:59 p.m. ET/ 8:59 p.m. PT on June 11, 2010. Access numbers for the replay are: 1-888-286-8010 (domestic) and 1-617-801-6888 (international), and the passcode is 40366411.

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 biological expertise and integrated research and development capabilities to generate a pipeline of development compounds with significant therapeutic and commercial potential for the treatment of cancer and potentially other serious diseases. Currently, Exelixis' broad product pipeline includes investigational compounds in phase 3, phase 2, and phase 1 clinical development. Exelixis has established strategic corporate alliances with major pharmaceutical and biotechnology companies, including Bristol-Myers Squibb Company, sanofi-aventis, GlaxoSmithKline, Genentech (a wholly owned member of the Roche Group), Boehringer Ingelheim, Pfizer Inc., 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.

Exelixis, Inc.
Charles Butler, 650-837-7277
Vice President,
Investor Relations
and Corporate Communications
cbutler@exelixis.com
or
DeDe Sheel, 650-837-8231
Associate Director,
Investor Relations
dsheel@exelixis.com