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                                                                   EXHIBIT 10.45

                                           *** TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                          UNDER 17 C.F.R. SECTIONS 200.80(b)(4),
                                                            200.83 AND 240.24b-2



                                  CONFIDENTIAL
                       ASSIGNMENT AND AMENDMENT AGREEMENT



        This Assignment and Amendment Agreement is made and entered as of
September 9, 1998 (the "Effective Date"), by and among Amylin Pharmaceuticals,
Inc., having a principal place of business at 9373 Towne Centre Drive, San
Diego, California, 92121 ("Amylin"); Bachem California, having a principal place
of business at 3132 Kashiwa Street, Torrance, California, 90505 ("Bachem");
Ortho-Biotech Inc., having a principal place of business at U.S. Route 202
South, Raritan, New Jersey, 08869 ("Ortho-Biotech").

        WHEREAS, Amylin, Bachem and Ortho-Biotech entered into an Agreement
dated July 2, 1997 directed to the manufacturing and supply of pramlintide (the
"Supply Agreement");

        WHEREAS, Amylin and Lifescan Inc., an affiliate of Ortho-Biotech entered
into a Collaboration Agreement effective as of June 20, 1995 which agreement was
amended by Letter Agreements dated August 2, 1996 and March 27, 1997 (together
the "Collaboration Agreement");

        WHEREAS, Lifescan has provided notice of termination to Amylin of the
Collaboration Agreement pursuant to its terms and such termination is to become
effective in August;

        WHEREAS, as a result of such notice of termination, Ortho-Biotech wishes
to assign rights and obligations under the Supply Agreement to Amylin and Amylin
wishes to accept such assignment; and

        WHEREAS, the parties to the Supply Agreement wish to make certain
amendments to the Supply Agreement including but not limited to change of the
delivery schedule and changes in the termination provisions.

        NOW, THEREFORE, in consideration of the following premises and terms and
conditions set forth hereinafter, the parties agree as follows:



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<PAGE>   2

Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



        1. Pursuant to Paragraph 17 of the Supply Agreement, Ortho-Biotech
hereby assigns to Amylin, and Amylin hereby accepts from Ortho-Biotech, all
rights and obligations of Ortho-Biotech under the Supply Agreement, with the
exception that Ortho-Biotech remains a party to the Supply Agreement with
respect to the three (3) Validation Lots described in Paragraph 2.2 of the
Supply Agreement. For example, such Validation Lots will be delivered to
Ortho-Biotech and will be paid for by Ortho-Biotech.

        2. The assignment in Section 1 of this Agreement is not intended to, and
it is hereby agreed that it does not, expressly or by implication, affect the
rights or obligations of the parties accrued prior to the Effective Date. Bachem
consents to such assignment.

        3. In the Definitions article of the Supply Agreement, add a definition
which reads as follows: "Major Market Country" means any of France, Germany,
Great Britain, Italy, Japan or the United States."

        4. In paragraph 2.2 of the Supply Agreement, change the schedule recited
therein to the following schedule:

        A total of [...***...] over the period [...***...] in accordance with
the schedule below:


                                                      VALIDATION LOTS

        [...***...]                  [...***...] lots no later than [...***...],
                                     pursuant to an issued Purchase Order, a
                                     copy of which is attached hereto as
                                     Exhibit 3.

                                                     COMMERCIAL LOTS

        [...***...]                  [...***...] lots by end of [...***...]
                                     pursuant to a Purchase Order issued on or
                                     before [...***...].



                                       2     * CONFIDENTIAL TREATMENT REQUESTED

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Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



        [...***...]                  [...***...] lot delivered by [...***...]
                                     pursuant to a Purchase Order issued on or
                                     before [...***...].

                                     [...***...] lots delivered at a rate of
                                     approximately every [...***...] in
                                     [...***...] beginning after [...***...]
                                     pursuant to a Purchase Order issued on or
                                     before [...***...].

        [...***...]                  [...***...] gram lots delivered at a rate
                                     of approximately every [...***...] in the
                                     year [...***...] pursuant to a Purchase
                                     Order issued on or before [...***...].
                                     2001.

        [...***...]                  [...***...] gram lots delivered at a rate
                                     of approximately every [...***...] in the
                                     year [...***...] pursuant to a Purchase
                                     Order issued on or before [...***...].

        5. Delete the following from paragraph 2.2 of the Supply Agreement:
"Purchase Orders will be issued at least six months in advance of the delivery
date for the individual purchase orders."

        6. Purchase Order No [...***...], issued by Ortho-Biotech to Bachem for
[...***...] of Product is hereby cancelled in its entirety.




                                       3     * CONFIDENTIAL TREATMENT REQUESTED

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Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



        7. Replace paragraph 3.2 of the Supply Agreement with the following:

                3.2 On or before the date specified for delivery of each lot,
        Bachem shall deliver samples (in sample sizes specified by Amylin) of
        such lot of Product to Amylin for testing ("Testing Samples"). The
        Testing Samples will be prepared and packed by Bachem in accordance with
        Amylin SOP-373-038 and SOP-373-015. If such lot is accepted by Amylin in
        accordance with Paragraph 4.1, Bachem shall deliver the remainder of
        such lot of Product ("Commercial Material") to a carrier specified by
        Amylin for shipment to the location(s) specified by Amylin. Each lot of
        Commercial Material will be packed by Bachem in accordance with Amylin
        SOP-373-015.

        8. Paragraph 4.1, lines 1-2 of the Supply Agreement: Replace "each
shipment of Product sold hereunder" with "Testing Samples for each lot of
Product." Throughout the remainder of Paragraph 4.1, replace "shipment" with
"lot."

        9. Paragraph 6, line 2 of the Supply Agreement: Replace "lot of Product"
with "Testing Samples for each lot of Product."

        10. In paragraph 7.2(c) of the Supply Agreement, substitute the first
paragraph which ends with the word "follows:" with the following:

        Amylin may terminate this Agreement by giving Bachem thirty (30) days
        prior written notice in each of the following situations: (i) upon
        notice from the FDA that Bachem is not an approved commercial supplier
        of Product or failure of Bachem to successfully complete its
        pre-approval inspection (PAI), (ii) as a consequence of clinical trial
        results obtained, Amylin determines in its sole discretion that the
        quantities of Product specified in the Agreement are not needed by
        Amylin, (iii) the FDA notifies Amylin that it will not approve the NDA
        directed to the Product or it is not approved by [...***...], (iv)
        Amylin withdraws the NDA directed to the Product or (v) Amylin withdraws
        the Product from the market. Notwithstanding the foregoing, termination
        as a consequence of clinical trial results under paragraph 7.2(c)(ii)
        will not relieve Amylin of its obligation to accept and pay for
        quantities of material previously ordered



                                       4     * CONFIDENTIAL TREATMENT REQUESTED

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Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



        pursuant issued purchase orders. If Amylin terminates this Agreement
        under any of 7.2(c)(ii), (iii), (iv) or (v), then Amylin agrees to
        reimburse Bachem for a portion of its investment cost for plant and
        equipment, as follows:

        11. In paragraph 7.2(c) of the Supply Agreement, substitute the last
paragraph with the following two paragraphs:

                If Amylin terminates this Agreement under any of Paragraphs
        7.2(c)(ii), (iii), (iv) or (v), Amylin shall compensate Bachem for its
        out-of-pocket costs associated with any work in progress, including
        expenses for raw materials purchased and prepared to support up to the
        next twelve months of production in accordance with the schedule set
        forth in paragraph 2.2.

                Notwithstanding 7.2(c)(ii), in the event that, as a consequence
        of clinical trial results obtained, Amylin determines in its sole
        discretion that the quantities of Product specified in the Agreement are
        not needed by Amylin, but that some quantities of Product are needed by
        Amylin, the parties shall negotiate in good faith to modify Paragraph
        2.2 (quantities and delivery dates), rather than terminate the
        Agreement.


        12. In paragraph 15, line 2 of the Supply Agreement: replace "New York"
with "California."

        13. At the end of the Supply Agreement, add new Article 24 which reads
as follows:

        24. Assurance of Payment. Concurrently with the signing of the
        Assignment and Amendment Agreement by all parties, Amylin agrees to
        deposit [...***...], which represents [...***...] of the maximum
        termination fee due under paragraph 7.2(c), into Escrow or other
        arrangement or instrument which has a similar degree of surety (e.g., an
        irrevocable letter of credit). The amount in escrow (or similar
        arrangement or instrument) shall be adjusted upward or downward as
        follows. On or before [...***...], Amylin agrees to add [...***...],



                                       5      * CONFIDENTIAL TREATMENT REQUESTED
<PAGE>   6
Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



        Concurrently with the issuance of the first purchase order for delivery
        of Product in [...***...]or thereafter, Amylin will add [...***...],
        which represents the approximate cost of raw materials and work in
        progress for one [...***...] lot of Product. After the purchase of
        [...***...] of Product under this Agreement, the amount in escrow (or
        similar arrangement or instrument) shall be reduced by [...***...].
        After the purchase of [...***...] of Product under this Agreement, the
        amount in escrow (or similar arrangement or instrument) shall be reduced
        by an additional [...***...]. All interest or other income, if any,
        arising from the amount in escrow (or similar arrangement or instrument)
        shall be paid to Amylin. Notwithstanding the foregoing, this Paragraph
        24 shall remain in effect only until marketing approval is obtained for
        pramlintide in a Major Market Country. After receipt of marketing
        approval for pramlintide in a Major Market Country, any and all funds
        then in escrow (or similar arrangement or instrument) will be returned
        to Amylin, and Amylin will have no obligation to deposit any further
        amount into escrow (or similar arrangement or instrument). Additionally,
        in the event Amylin and Bachem believe that a normal and customary
        business relationship exists between the parties, the parties will
        discontinue the escrow-type arrangement described in this Paragraph 24.

        14. Add a new Exhibit 3 (Purchase Order) to the Supply Agreement, which
is attached hereto as Exhibit A to this Assignment and Amendment and
incorporated herein by this reference.

        15. Replace the current Exhibit 1 to the Supply Agreement (Product
Specifications) with the revised Exhibit 1 to the Supply Agreement which is
attached hereto as Exhibit B to this Assignment and Amendment Agreement and
incorporated herein by this reference.

        16. Replace the current Exhibit 4 to the Supply Agreement (Alternative
Dispute Resolution Procedure) with the revised Exhibit 4 to the Supply Agreement
which is attached as Exhibit C to this Assignment and Amendment Agreement and
incorporated herein by this reference.


                                       6     * CONFIDENTIAL TREATMENT REQUESTED

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        17. This Assignment and Amendment Agreement shall be construed,
interpreted and governed by the laws of the State of California.


ORTHO-BIOTECH, INC.



By:     /s/ DAVID E. WILLIAMS
   -------------------------------

Title:  Vice President - Operations
      ----------------------------

Date:   June 4, 1999
     -----------------------------


AMYLIN PHARMACEUTICALS, INC.



By:     /s/ JOSEPH C. COOK, JR.
   -------------------------------

Title:  Chairman & CEO
      ----------------------------

Date:   11 June 1999
     -----------------------------


BACHEM CALIFORNIA



By:     /s/ JOSE DE CHASTONAY
   -------------------------------

Title:  President
      ----------------------------

Date:   11 June 1999
     -----------------------------





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Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998



                                    EXHIBIT A
                                       TO
                       ASSIGNMENT AND AMENDMENT AGREEMENT

                          EXHIBIT 3 TO SUPPLY AGREEMENT

                                 PURCHASE ORDER




                                   [...***...]






                                       8     * CONFIDENTIAL TREATMENT REQUESTED

<PAGE>   9


Bachem California                                                  CONFIDENTIAL
ASSIGNMENT AND AMENDMENT AGREEMENT
September 9, 1998




                                    EXHIBIT B
                                       TO
                       ASSIGNMENT AND AMENDMENT AGREEMENT

                          EXHIBIT 1 TO SUPPLY AGREEMENT

                                 SPECIFICATIONS



                                   [...***...]










                                       9     * CONFIDENTIAL TREATMENT REQUESTED


<PAGE>   10

                                    EXHIBIT C
                                       TO
                       ASSIGNMENT AND AMENDMENT AGREEMENT

                          EXHIBIT 4 TO SUPPLY AGREEMENT

                    ALTERNATIVE DISPUTE RESOLUTION PROCEDURE



        1. Any dispute between the parties regarding payment obligations shall
be resolved by arbitration pursuant to the rules of the American Arbitration
Association and the California Code of Civil Procedure, except as provided
herein. There shall be three arbitrators, at least one of which shall be
knowledgeable in protein chemistry and the manufacture of peptides, and at least
one of which shall be knowledgeable in United States Food and Drug
Administration requirements for the clinical testing of new chemical entities
prior to licensure. Any claim for payment must be asserted to the other party
within 90 days and a demand for arbitration filed with the American Arbitration
Association within one year of the date the claim arises. The arbitration
hearing shall be held within six months after the demand is filed. Discovery in
accordance with California Code of Civil Procedure shall be allowed and any
dispute shall be resolved by a telephone conference or in person by an attorney
arbitrator (who may but need not be one of the three arbitrators deciding the
claim) designated by the American Arbitration Association.

        2. The arbitration hearing shall be held in San Diego, California.
Either party may petition the Court to confirm the award of the arbitration, and
upon confirmation judgement shall be entered with the same force and effect as a
judgment in a civil action.










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