Seven Abstracts Accepted for Presentation at ASCO

SOUTH SAN FRANCISCO, Calif., May 21 /PRNewswire-FirstCall/ -- Exelixis, Inc. (Nasdaq: EXEL) announced today that it will hold an investor and analyst briefing in conjunction with the 44th Annual Meeting of the American Society of Clinical Oncology (ASCO) from 6:00 p.m. to 8:00 p.m. CT on Monday, June 2, 2008.

Participants:

-- George A. Scangos, PhD, President and Chief Executive Officer
-- Michael M. Morrissey, PhD, President of Research and Development
-- Gisela M. Schwab, MD, Executive Vice President and Chief Medical Officer

Topics:

-- XL184 (targets: MET, VEGFR2, RET)
-- XL147 (targets: PI3K)
-- XL765 (targets: PI3K, mTOR)
-- XL647 (targets: EGFR, HER2, VEGFR2)
-- XL880* (targets: MET, VEGFR2)
-- XL281 (targets: RAF)

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

The event will be webcast and may be accessed in the Event Calendar page under Investors at http://www.exelixis.com.

An archived replay of this webcast will be available until 9:00 p.m. PT/12:00 a.m. ET on July 2, 2008. Access numbers for this replay are: 1-888- 286-8010 (domestic) and +1-617-801-6888 (international); the replay passcode is: 42662164.

ASCO Presentations

Saturday, May 31

-- XL647 (EGFR, HER2, VEGFR2) -- Poster & Discussion "A phase 1 study of XL647, an EGFR, HER2, VEGFR2 inhibitor, administered orally daily to patients (pts) with advanced solid malignancies (ASM)"
Day: Saturday, May 31
Session: Developmental Therapeutics: Molecular Therapeutics
Time (Poster): 8 a.m.-noon Location: W375e Lobby
Time (Discussion): Noon-1 p.m. Location: W375a
Poster Number: 5 Abstract Number: 3528
Presenter: Heather A. Wakelee, MD

-- XL880* (MET, VEGFR2) -- Poster
"A phase 2 study of the dual MET/VEGFR2 inhibitor GSK1363089 (XL880) in patients with papillary renal carcinoma (PRC)"
Day: Saturday, May 31
Session: Genitourinary Cancer
Time: 8 a.m.-noon
Location: S Hall A1
Poster Number: 5G Abstract Number: 5103
Presenter: Ramiprasad Srinivasan, MD, PhD

-- XL765 (PI3K, mTOR) -- Oral Presentation
"A phase 1 dose-escalation study of the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of a novel PI3K inhibitor, XL765, administered orally to patients (pts) with advanced solid tumors"
Day: Saturday, May 31
Session: PI-3 Kinase/mTOR Directed Agents
Time: 1:45-2:15 pm
Location: W375a
Abstract Number: 3510
Presenter: Kyriakos Papadopoulis, MD

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

Sunday, June 1

-- XL184 (RET, MET, VEGFR2) -- Oral Presentation
"A phase 1 study of XL184, a RET, VEGFR2, and MET kinase inhibitor, in patients (pts) with advanced malignancies, including pts with medullary thyroid cancer (MTC)"
Day: Sunday, June 1
Session: Developmental Therapeutics: Molecular Therapeutics
Time: 10-10:15 a.m.
Location: W375a
Abstract Number: 3522
Presenter: Ravi Salgia, MD, PhD

-- XL647 (EGFR, HER2, VEGFR2) -- Poster
"Activity of XL647 in clinically selected NSCLC patients (pts) enriched for the presence of EGFR mutations: Results from phase 2"
Day: Sunday, June 1
Session: Lung Cancer -- Metastatic
Time: 2-6 p.m.
Location: S Hall A1
Poster Number: 42H Abstract Number: 8053
Presenter: Naiyer A Rizvi, MD

Monday, June 2

-- XL647 (EGFR, HER2, VEGFR2) -- Poster & Discussion
"Activity and tolerance of XL647 in NSCLC patients with acquired resistance to EGFR-TKIs: Preliminary results of a phase 2 trial"
Day: Monday, June 2
Session: Lung Cancer -- Metastatic
Time (Poster): 8 a.m.-noon Location: W375e Lobby
Time (Discussion): Noon-12:15 p.m. Location: W375d
Poster Number: 9 Abstract Number: 8028
Presenter: Vincent A. Miller, MD

-- XL880* (MET, VEGFR2) -- Poster
"Preliminary activity of GSK1363089 (XL880), a dual MET/VEGFR2 inhibitor, in MET amplified poorly differentiated gastric cancer (PDGC): Interim results of a multicenter phase 2 study"
Day: Monday, June 2
Session: Gastrointestinal (Noncolorectal) Cancer
Time: 8 a.m.-noon
Location: S Hall A1
Poster Number: 33D Abstract Number: 4572
Presenter: Minaxi P. Jhawer, MD

* 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, 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 Maxwell
Harrison, Senior Manager Corporate Communications, +1-650-837-7012,
sharrison@exelixis.com, both of Exelixis, Inc.
Web site: http://www.exelixis.com