EXHIBIT 10.53  ***Text
Omitted and Filed Separately with the Securities and Exchange Commission.  Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(b)(4) and
240.24b-2  [AMYLIN LETTERHEAD]  October 30, 2009  Takeda Pharmaceutical Company Limited 1-1, Doshomachi 4-chome,
Chuo-ku Osaka 540-8645, Japan Attention: Mr. Yasuchika Hasegawa, President& CEO  Re:License, Development and
Commercialization Agreement dated as of October 30, 2009 (the Agreement)
by and between Takeda Pharmaceutical Company Limited (Takeda) and Amylin
Pharmaceuticals, Inc. (Amylin)  Ladies and Gentlemen:  This letter (the Letter) will confirm the understanding of
Takeda and Amylin regarding certain matters relating to the Agreement.  Capitalized terms used but not otherwise
defined in this Letter shall have
the meanings provided in the Agreement. 
Takeda and Amylin, intending to be legally bound, hereby agree as
follows:  1.TheProduct which is a [***] is intended by the Parties
to be a [***] under the [***], including, without limitation, for purposes of
[***].  2.Amylin shall take all reasonable steps necessary to maintain at all
times during the term of the Agreement the[***], including the [***]
to Takeda,that are[***]to[***]the[***], and Amylin shall be
responsible for making any and all [***] necessary to [***]; provided, however,
except with respect to [***]  to use[***]([***])with respect to[***]([***]), Amylin shall have no obligations to Takeda pursuant to this Letter to
the extent any [***] causes [***].  3.(A) Amylin agrees that the
provisions of Paragraph 3(B) shall be applicable,if: (a)(i)[***]with respect to the[***]prior to[***]by Takeda under the Agreement; or (ii) there
is a Partial Termination of the Agreement with respect to the[***]of the[***]by
Takeda under the Agreement; (b)[***]that the[***]is nota [***] under the [***],
and therefore the exception under [***][***]does not apply tothe[***];and (c) [***] from
Amylin to  *** Confidential Treatment Requested


***Text
Omitted and Filed Separately with the Securities and Exchange Commission.  Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(b)(4) and
240.24b-2  [***] the [***] pursuant to [***] and the [***] is
[***] or its affiliates or sublicensees.  (B) 
If the conditions set forth in Paragraph 3(A) are met, then, with respect
to only the [***] or its Affiliates or sublicensees (the [***]): (i) the [***] will be
considered a [***] with respect to the [***]; (ii) the [***] for the [***]  will be deemed to have [***]; (iii) the
[***]  on the [***] will be payable
pursuant to [***]of the Agreementduring the
[***]  for the [***]; and (iv) upon
[***]  of the [***], Takeda will no
longer be obligated to make [***] on the [***] 
to Amylin.  4.In the event that Amylin obtains[***]that clarify, in Takedas reasonable
judgment, that Amylin has secured[***](including by clarifying that the[***]is a [***][***]),including the [***] to
Takeda,that are
necessary or useful to[***]the[***] at all times during the term of the
Agreement, then
Amylin shall provide written notice and a copy of such[***](the Clarification) to Takeda, and
Takeda shall terminate this Letter by providing written notice to Amylin within
thirty (30) days of receipt of the Clarification, after which this Letter shall
be of no further force and effect.  In
the event that Takeda does not object to the Clarification by written notice to
Amylin within thirty (30) days of receipt of the Clarification, the
Clarification shall be deemed reasonable and this Letter shall be of no further
force and effect.  5.The provisions of this Letter shall supersede any
conflicting terms contained in the last sentence of[***]of the Agreement.  6.The Parties hereby agree that this Letter shall be
subject to the terms and conditions of the Agreement, and all references to Agreement
and words such as herein, hereof and hereunder in the Agreement shall
include the terms and conditions set forth in this Letter.  7.This Letter may be executed in two counterparts
(including, without limitation, by facsimile signature), each of which shall be
deemed an original, but both of which together shall constitute one and the
same instrument.  *** Confidential Treatment Requested


***Text Omitted and Filed
Separately with the Securities and Exchange Commission.  Confidential Treatment Requested Under 17 C.F.R. Sections 200.80(b)(4)
and 240.24b-2  If the foregoing is acceptable, please countersign this Letter and return it to the
undersigned.  Sincerely,AMYLIN
  PHARMACEUTICALS, INC.By:
  /s/ Daniel M.
  BradburyName:
  Daniel M.
  BradburyTitle:
  President &
  CEO   Agreed to and accepted as of the Effective Date:  TAKEDA PHARMACEUTICAL COMPANY LIMITED  By:
  /s/ Yasuchika HasegawaName:
  Yasuchika HasegawaTitle:
  President& CEO