EXHIBIT A

Exhibit 10.3

April 09, 2009

Eli Lilly and Company
Lilly Corporate Center

Indianapolis, IN 46285

Attention:  Bryce Carmine

Dear Bryce:

This letter confirms our understanding with respect to certain amendments to the Collaboration Agreement and the co-location of certain Lilly personnel at Amylin’s facilities in furtherance of Amylin’s and Lilly’s efforts under the Collaboration Agreement to operate efficiently and effectively.  Capitalized terms used but not defined herein have the meanings given to them in the collaboration Agreement.

1.             The last sentence of Section 12.3(c) of the Collaboration Agreement is hereby amended and restated to read as follows: “If such termination occurs after Product Launch, such termination shall be effective one (1) year after the date of Amylin’s receipt of written notice from Lilly.  Within 60 days of Lilly’s notice, the parties will negotiate in good faith, and Alliance Steering Committee will approve, a mutually agreeable termination transition plan.”

2.             As of April 1, 2009, notwithstanding any term of the Collaboration Agreement to the contrary, including but not limited to the definition of the term “FTE” or the term “Reimbursable Marketing Expenses,” each Party’s internal costs, including headcount, that are specifically attributable to the Development or Commercialization of Product (e.g. specific finance/accounting support, managed care contracting, etc.) as mutually determined and agreed by the Alliance Steering Committee shall be reimbursed in accordance with each Party’s respective standard cost accounting procedures.  The ASC will be responsible for approving the methodology, plan and rates for these previously unshared expenses.  Each Party shall insure that such internal costs are not unfairly allocated to the Development or Commercialization of Product, and that headcount is allocated based on actual time spent on the Product similar to the procedures specified in Section 1.48 of the Collaboration Agreement.  Such internal costs shall be reimbursed in accordance with each Party’s standard cost accounting procedures.  For purposes of clarification, such internal Reimbursable Marketing Expenses shall include internal marketing costs, whether incurred by Amylin or Lilly, including internal expenses of the types describes in clauses (i) through (xviii) of Section 1.100 of the Collaboration Agreement, even if incurred internally by the Parties.

3.             With regard to certain Lilly employees to be co-located at Amylin’s facilities in furtherance of the efforts between Lilly and Amylin to operate efficiently and effectively (the “Co-located Lilly Employees”), the Parties shall agree upon a set of operating and human resources principles (the “Principles”) to be agreed to by April 16, 2009 and approved by the Alliance Steering Committee.  Those Principles will address matters deemed necessary for the operation of the Alliance business and the co-location of employees including, without limitation the items set forth on Exhibit A hereto.

If this letter correctly reflects our agreement as to the foregoing matters, please sign in the space provided below and return a signed copy of this letter to me.  Unless otherwise set forth in this letter, the terms of the Collaboration Agreement remain unmodified and in full force and effect.

Regards,

EXHIBIT A

The Operating and Human Resources Principles shall address, without limitation, the following needs, as well as addressing other operating and human resource matters as the parties deem advisable or necessary: