THIS SUBLEASE (this “Sublease”), dated as of August 5, 2004 (the “Execution Date”), is entered into by
and between SIEBEL SYSTEMS, INC. , a Delaware corporation (“Sublandlord”), and ONYX
PHARMACEUTICALS, INC. , a Delaware corporation (“Subtenant”).
1. BASIC PROVISIONS.
1.1 Sublease Premises: The “Sublease Premises” under this Sublease consists of approximately 23,222
rentable square feet located on the 12th floor in the building commonly known as Watergate Office Towers IV,
located at 2100 Powell Street, Emeryville, California (“Building”). The Sublease Premises are a portion of those
certain premises (“Master Premises”) containing approximately 298,089 rentable square feet which are demised
pursuant to the Master Lease to Sublandlord. The Sublease Premises are depicted on Exhibit A to this
1.2 Master Landlord: CA-Emeryville Properties Limited, a Delaware limited partnership.
1.3 Master Lease: Lease dated August 16, 1999 (“Original Lease”) as amended by (i) Amendment
Number One to Lease, dated as of October 26, 2000 (“First Amendment”); (ii) Amendment Number Two to
Lease dated as of June 29, 2001 (“Second Amendment”); and (iii) Third Amendment dated as of September 26,
2003, (“Third Amendment”), a copy of which is attached hereto as Exhibit B .
1.4 Term: This Sublease shall begin on the Commencement Date and end on the Expiration Date (“Term”),
unless terminated earlier in accordance with the terms and conditions of this Sublease. Promptly following a
request therefor, Subtenant agrees to execute a Sublease Commencement Date Certificate in the form attached
as Exhibit D setting forth the actual Commencement Date and the Expiration Date.
1.5 Commencement Date: Estimated to be November 1, 2004, but in any case upon the date which is the
later of (i) the date Sublandlord tenders possession of the Sublease Premises to Subtenant or (ii) the date the
Master Landlord gives its consent to this Sublease, provided that,