EXHIBIT 10.1

FIRST AMENDMENT

THIS FIRST AMENDMENT (this First Amendment) dated as of August 31,
2006 (the Effective Date) to the Employment Agreement dated as of March 13, 2006 (the Agreement) by and between SAVVIS, Inc., a Delaware corporation with its principal place of business at St. Louis, Missouri (the
Company), and Philip J. Koen, of San Jose, California (the Executive).

WHEREAS, the Company and the Executive
jointly desire to amend certain provisions of the Agreement in the manner provided for in this First Amendment;

NOW, THEREFORE, for
valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and in consideration of the premises contained herein, the Company and the Executive hereby agree as follows:



| | 1. | Amendment of Section 7 (Change of Control) of the Agreement. Section 7(i) of the Agreement is hereby amended by deleting not earlier than nine months
following the Change of Control and substituting in lieu thereof not earlier than six months following the Change of Control.
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| | 2. | No Other Amendments. Except as expressly amended, modified and supplemented by this First Amendment, the provisions of the Agreement are and shall remain in full force and
effect.
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| | 3. | Governing Law. This is a Missouri contract and shall be construed and enforced under and be governed in all respects by the laws of Missouri, without regard to the conflict
of laws principles thereof.
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| | 4. | Counterparts. This First Amendment may be executed in counterparts, all of which shall be considered one and the same agreement, and shall become effective when one or more
counterparts have been signed by each of the parties and delivered to the other party.
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IN WITNESS WHEREOF, this First
Amendment has been executed as a sealed instrument by the Company, by its duly authorized representative, and by the Executive, as of the date first above written.



|                   |  |             |  |                      
|------------------ |  | ----------- |  | ---------------------
|THE EXECUTIVE:     |  | THE COMPANY
|                   |  |            
|/s/ Philip J. Koen |  | By:         |  | /s/ Jonathan C. Crane
|                   |  | Title:      |  | President