EX-31.1 3 exel2017033110-qaexhibit311.htm EXHIBIT 31.1

Exhibit

Exhibit 31.1

CERTIFICATION

I, Michael M. Morrissey, Ph.D., certify that:

1. I have reviewed this 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.

/s/ MICHAEL M. MORRISSEY

Michael M. Morrissey, Ph.D.

President and Chief Executive Officer

(Principal Executive Officer)

Date: July 14, 2017