Amendment No. 1 to Distribution & Inventory Management Services Agreement between McKesson Corporation and Prometheus Laboratories Inc.

Exhibit 10.29

AMENDMENT NO.1
TO THE DISTRIBUTION & INVENTORY MANAGEMENT
SERVICES AGREEMENT

        THIS AMENDMENT NO. 1, dated as of December 10^th, 2004 (the "Amendment"), by and between McKesson Corporation, a Delaware corporation with its principal place of business located at One Post Street, San Francisco, CA 94104-5296 ("McKesson"), and Prometheus Laboratories Inc. ("Prometheus"), amends the Distribution & Inventory Management Services Agreement, dated as of May 1^st, by and between McKesson and Prometheus, as follows (unless otherwise defined herein, all capitalized terms shall have the same meaning ascribed to them in the Agreement):

1.

Addition of a New Product NDC# to Distribution and Inventory Management Services Agreement

        The Distribution & Inventory Management Services Agreement by and between McKesson and Prometheus shall be amended to expand the Exhibit A Products section to include one (1) new NDC Product #'s as follows:

        The new NDC # will be added to the Distribution & Inventory management Services Agreement Exhibit A Products section and have an effective date of January 1^st, 2005.

        All other Terms and Conditions of the Distribution & Inventory Management Services Agreements will remain in effect.

        IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed as of the date first set forth above.

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Exhibit 10.29