EXELIXIS, INC. - FORM 10-Q/A - EX-31.3 - CERTIFICATION REQUIRED BY RULE 13A-14(A) OR RULE 15D-14(A) - December 18, 2009

Attached files

file filename
10-Q/A - FORM 10-Q/A AMENDMENT NO. 1 - EXELIXIS, INC.d10qa.htm
EX-31.4 - CERTIFICATION REQUIRED BY RULE 13A-14(A) OR RULE 15D-14(A). - EXELIXIS, INC.dex314.htm
EX-10.4 - THIRD AMENDMENT, DATED JULY 1, 2009, TO THE CONTRACT RESEARCH AGREEMENT - EXELIXIS, INC.dex104.htm
EX-10.1 - LICENSE AGREEMENT, DATED MAY 27, 2009, BETWEEN EXELIXIS, INC. AND SANOFI-AVENTIS - EXELIXIS, INC.dex101.htm
EX-10.2 - COLLABORATION AGREEMENT, DATED MAY 27, 2009, BETWEEN SANOFI-AVENTIS - EXELIXIS, INC.dex102.htm
EX-10.5 - FOURTH AMENDMENT, DATED JULY 1, 2009, TO THE CONTRACT RESEARCH AGREEMENT - EXELIXIS, INC.dex105.htm

Exhibit 31.3

CERTIFICATION

I, George A. Scangos, Ph.D., Chief Executive Officer of Exelixis, Inc., certify that:

1. I have reviewed this Amendment No. 1 to the quarterly report on Form 10-Q/A of Exelixis, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: December 18, 2009

 

/s/ George A. Scangos
George A. Scangos, Ph.D.
President and Chief Executive Officer

EXELIXIS, INC. Reports