<PAGE>   1

                                                                     EXHIBIT 4.5

                               PURCHASE AGREEMENT


               THIS AGREEMENT is made as of the 11th day of May, 2001, by and
between Amylin Pharmaceuticals, Inc., a corporation organized under the laws of
the State of Delaware (the "Company"), with its principal offices at 9373 Towne
Centre Drive, San Diego, California 92121, a stockholder of the Company who is
listed on Exhibit A-1 hereto (the "Selling Stockholder") and the purchaser whose
name and address is set forth on the signature page hereof (the "Purchaser").

               IN CONSIDERATION of the mutual covenants contained in this
Agreement, the Company, the Selling Stockholder and the Purchaser agree as
follows:

               SECTION 1. Authorization of Sale of the Shares. Subject to the
terms and conditions of this Agreement, the Company has authorized the sale of
up to 3,485,000 shares (the "Company Shares") of common stock, par value $.001
per share (the "Common Stock"), of the Company and the Selling Stockholder has
authorized the sale of up to an aggregate of 600,000 shares (the "Selling
Stockholder Shares") of the Company's Common Stock. The Company Shares and the
Selling Stockholder Shares are referred to herein collectively as the "Shares."

               SECTION 2. Agreement to Sell and Purchase the Shares. At the
Closing (as defined in Section 3), (i) the Company will sell to the Purchaser,
and the Purchaser will buy from the Company, upon the terms and conditions
hereinafter set forth, the number of Shares (at the purchase price) equal to the
total number of Shares shown below to be purchased by the Purchaser, multiplied
by a fraction, the numerator of which is the number of Company Shares to be sold
by the Company pursuant to the Agreements (as defined below) and the denominator
of which is the total number of Shares to be sold pursuant to the Agreements and
(ii) the Selling Stockholder will sell to the Purchaser, and the Purchaser will
buy from the Selling Stockholder, upon the terms and conditions hereinafter set
forth, the number of Shares (at the purchase price) equal to the total number of
Shares shown below to be purchased by the Purchaser, multiplied by a fraction,
the numerator of which is the number of Selling Stockholder Shares to be sold by
the Selling Stockholder pursuant to the Agreements and the denominator of which
is the total number of Shares to be sold pursuant to the Agreements, upon the
terms and conditions hereinafter set forth, the number of Shares (at the
purchase price) shown below. If the quotient of any of the foregoing
calculations would not result in a whole number of shares, the Purchaser's
allocation between Selling Stockholder Shares and Company Shares shall be
determined by the Company and the Placement Agent in their reasonable
discretion.

<TABLE>
<CAPTION>
                                        Price Per
              Number to Be               Share In               Aggregate
                Purchased                 Dollars                 Price
           --------------------      ------------------      -----------------
<S>                                  <C>                     <C>
                                          $10.00
</TABLE>

<PAGE>   2

               The Company and the Selling Stockholder propose to enter into
this same form of purchase agreement with certain other investors (the "Other
Purchasers") and expect to complete sales of the Shares to them. The Purchaser
and the Other Purchasers are hereinafter sometimes collectively referred to as
the "Purchasers," and this Agreement and the agreements executed by the Other
Purchasers are hereinafter sometimes collectively referred to as the
"Agreements." The term "Placement Agent" shall mean Lehman Brothers Inc.

               SECTION 3. Delivery of the Shares at the Closing. The completion
of the purchase and sale of the Shares (the "Closing") shall occur at the
offices of Stroock & Stroock & Lavan LLP, 180 Maiden Lane, New York, New York
10038 as soon as practicable and as agreed by the parties hereto following
notification by the Securities and Exchange Commission (the "Commission") to the
Company of the Commission's willingness to declare effective the registration
statement to be filed by the Company pursuant to Section 8.1 hereof (the
"Registration Statement") at a place and time (the "Closing Date") to be agreed
upon by the Company, the Selling Stockholder and the Placement Agent and of
which the Purchasers will be notified by facsimile transmission or otherwise;
provided, however, that such date shall be no more than three business days
following the effectiveness of the Registration Statement.

               At the Closing, the Company and/or the Selling Stockholder shall
deliver to the Purchaser one or more stock certificates registered in the name
of the Purchaser, or, if so indicated on the Stock Certificate Questionnaire
attached hereto as Appendix I, in such nominee name(s) as designated by the
Purchaser in writing, representing the number of Shares set forth in Section 2
above and bearing an appropriate legend referring to the fact that the Shares
were sold in reliance upon the exemption from registration under the Securities
Act of 1933, as amended (the "Securities Act") provided by Section 4(2) thereof.
The Company will promptly substitute one or more replacement certificates
without the legend at such time as the Registration Statement is effective. The
name(s) in which the stock certificates are to be registered are set forth in
the Stock Certificate Questionnaire attached hereto as part of Appendix I. The
Company's obligation to complete the purchase and sale of the Company Shares and
deliver such stock certificate(s) to the Purchaser at the Closing shall be
subject to the following conditions, any one or more of which may be waived by
the Company: (a) receipt by the Company of same-day funds in the full amount of
the purchase price for the Company Shares being purchased hereunder; (b)
completion of the purchases and sales under the Agreements with all of the Other
Purchasers; and (c) the accuracy of the representations and warranties made by
the Purchasers and the fulfillment of those undertakings of the Purchasers to be
fulfilled prior to the Closing. The Selling Stockholder's obligation to complete
the purchase and sale of the Selling Stockholder Shares and deliver such stock
certificate(s) to the Purchaser at the Closing shall be subject to the following
conditions, any one or more of which may be waived by the Selling Stockholder:
(a) receipt by the Selling Stockholder of same-day funds in the full amount of
the purchase price for the Selling Stockholder Shares being purchased hereunder;
(b) completion of the purchases and sales under the Agreements with the Other
Purchasers; and (c) the accuracy of the representations and warranties made by
the Purchasers and the fulfillment of those undertakings of the Purchasers to be
fulfilled prior to the Closing. The Purchaser's obligation to accept delivery of
such stock certificate(s) and to pay for the Shares evidenced thereby shall be
subject to the


                                      -2-
<PAGE>   3

following conditions: (a) the Commission has notified the Company of the
Commission's willingness to declare the Registration Statement effective on or
prior to the 60th day after the date such Registration Statement was filed by
the Company; (b) that the representations and warranties made by the Company and
the Selling Stockholder herein were accurate in all material respects as of the
date of this Agreement, provided, however, that if any such representations or
warranties are incorrect or untrue as of the date of this Agreement, the Company
and/or the Selling Stockholder (as the case may be) shall have the longer of 20
business days and the date on which all other conditions in this Section 3 must
be satisfied, to cure the circumstances that caused such representations or
warranties to be incorrect or untrue and if such circumstances are cured within
that period, such representations and warranties shall be treated as true and
correct as of the date of this Agreement; and (c) that the Company and the
Selling Stockholder have fulfilled, in all material respects, all undertakings
to be fulfilled prior to Closing. The Purchaser's obligations hereunder are
expressly not conditioned on the purchase by any or all of the Other Purchasers
of the Shares that they have agreed to purchase from the Company and the Selling
Stockholder.

               SECTION 4. Representations, Warranties and Covenants of the
Company. Except as otherwise described in the Company's (i) annual report on
Form 10-K for the year ended December 31, 2000, and (ii) notice of annual
meeting and proxy statement relating to the Company's 2001 Annual Meeting of
Stockholders, each as filed by the Company with the Securities and Exchange
Commission (the "SEC Documents") and provided to the Purchaser, and in other
proprietary information that may have been disclosed by the Company to the
Purchaser in contemplation of this offering (including the documents
incorporated by reference therein, the "Company Information"), which qualifies
the following representations and warranties in their entirety, the Company
hereby represents and warrants to, and covenants with, the Selling Stockholder
and the Purchaser as follows:

               4.1 Organization and Qualification. The Company is a corporation
duly incorporated, validly existing and in good standing under the laws of the
State of Delaware and the Company is qualified to do business as a foreign
corporation in each jurisdiction in which qualification is required, except
where failure to so qualify would not reasonably be expected to have a material
adverse effect upon the business, financial condition, properties or operations
of the Company and its Subsidiary (as defined below) taken as a whole (a
"Material Adverse Effect"). The Company has one subsidiary, Amylin Europe
Limited (the "Subsidiary"). The Subsidiary is a direct wholly-owned subsidiary
of the Company. The Subsidiary is duly incorporated, validly existing and in
good standing under the laws of its jurisdiction of incorporation and is
qualified to do business as a foreign corporation in each jurisdiction in which
qualification is required, except where failure to so qualify would not have a
Material Adverse Effect.

               4.2 Authorized Capital Stock. Except as disclosed in or
contemplated by the Confidential Private Placement Memorandum dated May 7, 2001
prepared by the Company, including all Exhibits (except Exhibit C) supplements
and amendments thereto (the "Private Placement Memorandum"), the Company had
authorized and outstanding capital stock as set forth under the heading
"Capitalization" in the Private Placement Memorandum as of the date set


                                      -3-
<PAGE>   4

forth therein; the issued and outstanding shares of the Company's Common Stock
have been duly authorized and validly issued, are fully paid and nonassessable,
have been issued in compliance with all federal and state securities laws, were
not issued in violation of or subject to any preemptive rights or other rights
to subscribe for or purchase securities, and conform in all material respects to
the description thereof contained in the Private Placement Memorandum. Except as
disclosed in or contemplated by the Private Placement Memorandum, the Company
does not have outstanding any options to purchase, or any preemptive rights or
other rights to subscribe for or to purchase, any securities or obligations
convertible into, or any contracts or commitments to issue or sell, shares of
its capital stock or any such options, rights, convertible securities or
obligations. The description of the Company's stock, stock bonus and other stock
plans or arrangements and the options or other rights granted and exercised
thereunder, set forth in the Private Placement Memorandum accurately and fairly
presents the information required to be shown with respect to such plans,
arrangements, options and rights. With respect to the Subsidiary, (i) the
Company owns 100% of the Subsidiary's capital stock (except for directors'
qualifying shares), (ii) all the issued and outstanding shares of the
Subsidiary's capital stock have been duly authorized and validly issued, are
fully paid and nonassessable, have been issued in compliance with applicable
federal and state securities laws, were not issued in violation of or subject to
any preemptive rights or other rights to subscribe for or purchase securities,
and (iii) there are no outstanding options to purchase, or any preemptive rights
or other rights to subscribe for or to purchase, any securities or obligations
convertible into, or any contracts or commitments to issue or sell, shares of
the Subsidiary's capital stock or any such options, rights, convertible
securities or obligations.

               4.3 Issuance, Sale and Delivery of the Shares. The Company Shares
have been duly authorized and, when issued, delivered and paid for in the manner
set forth in this Agreement, will be duly authorized, validly issued, fully paid
and nonassessable, and will conform in all material respects to the description
thereof set forth in the Private Placement Memorandum. No preemptive rights or
other rights to subscribe for or purchase exist with respect to the issuance and
sale of the Company Shares by the Company pursuant to this Agreement. No
stockholder of the Company has any right (which has not been waived or has not
expired by reason of lapse of time following notification of the Company's
intent to file the registration statement to be filed pursuant to Section 8.1
(the "Registration Statement") to require the Company to register the sale of
any shares owned by such stockholder under the Securities Act of 1933, as
amended (the "Securities Act"), in the Registration Statement. No further
approval or authority of the stockholders or the Board of Directors of the
Company will be required for the issuance and sale of the Company Shares to be
sold by the Company as contemplated herein.

               4.4 Due Execution, Delivery and Performance of this Agreement.
The Company has full legal right, corporate power and authority to enter into
this Agreement and perform the transactions contemplated hereby. This Agreement
has been duly authorized, executed and delivered by the Company. The execution,
delivery and performance of this Agreement by the Company and the consummation
of the transactions herein contemplated will not violate any provision of the
organizational documents of the Company or the Subsidiary and will not result in
the creation of any lien, charge, security interest or encumbrance upon any


                                      -4-
<PAGE>   5

assets of the Company or the Subsidiary pursuant to the terms or provisions of,
or will not (i) conflict with, result in the breach or violation of, or
constitute, either by itself or upon notice or the passage of time or both, a
default under (A) any agreement, mortgage, deed of trust, lease, franchise,
license, indenture, permit or other instrument to which the Company or the
Subsidiary is a party or by which the Company or the Subsidiary or any of their
respective properties may be bound or affected and in each case which would have
a Material Adverse Effect, or (B) to the Company's knowledge, any statute or any
judgment, decree, order, rule or regulation of any court or any regulatory body,
administrative agency or other governmental body applicable to the Company or
the Subsidiary or any of their respective properties where such conflict,
breach, violation or default is likely to, result in a Material Adverse Effect.
No consent, approval, authorization or other order of any court, regulatory
body, administrative agency or other governmental body is required for the
execution and delivery of this Agreement or the consummation of the transactions
contemplated by this Agreement, except for compliance with the Blue Sky laws and
federal securities laws applicable to the offering of the Shares. Upon the
execution and delivery of this Agreement, and assuming the valid execution
thereof by the Selling Stockholder and the Purchaser, this Agreement will
constitute valid and binding obligations of the Company, enforceable in
accordance with its terms, except as enforceability may be limited by applicable
bankruptcy, insolvency, reorganization, moratorium or similar laws affecting
creditors' and contracting parties' rights generally and except as
enforceability may be subject to general principles of equity (regardless of
whether such enforceability is considered in a proceeding in equity or at law)
and except as the indemnification agreements of the Company in Section 8.3
hereof may be legally unenforceable.

               4.5 Accountants. Ernst & Young LLP, who has expressed its opinion
with respect to the consolidated financial statements to be included in the
Registration Statement and the Prospectus which forms a part thereof, are
independent accountants as required by the Securities Act and the rules and
regulations promulgated thereunder (the "Rules and Regulations").

               4.6 No Defaults. Except as disclosed in the Private Placement
Memorandum, and except as to defaults, violations and breaches which
individually or in the aggregate would not be material to the Company or the
Subsidiary taken as a whole, neither the Company nor the Subsidiary is in
violation or default of any provision of its certificate of incorporation or
bylaws, or in breach of or default with respect to any provision of any
agreement, judgment, decree, order, mortgage, deed of trust, lease, franchise,
license, indenture, permit or other instrument to which it is a party or by
which it or any of its properties are bound; and, to the Company's knowledge,
there does not exist any state of fact which, with notice or lapse of time or
both, would constitute an event of default on the part of the Company or the
Subsidiary as defined in such documents, except such defaults which individually
or in the aggregate would not have a Material Adverse Effect.

               4.7 Contracts. The contracts described in the Private Placement
Memorandum that are material to the Company or the Subsidiary are in full force
and effect on the date hereof; and neither the Company nor the Subsidiary is,
nor to the Company's knowledge is any other


                                      -5-
<PAGE>   6

party in breach of or default under any of such contracts which would have a
Material Adverse Effect.

               4.8 No Actions. Except as disclosed in the Private Placement
Memorandum, there are no legal or governmental actions, suits or proceedings
pending or, to the Company's knowledge, threatened in writing to which the
Company or the Subsidiary is or may be a party or of which property owned or
leased by the Company or the Subsidiary is or may be the subject, or related to
environmental or discrimination matters, which actions, suits or proceedings,
individually or in the aggregate, might prevent or might reasonably be expected
to materially and adversely affect the transactions contemplated by this
Agreement or result in a Material Adverse Effect; and no labor disturbance by
the employees of the Company exists, to the Company's knowledge, or is imminent
which might reasonably be expected to have a Material Adverse Effect. Neither
the Company nor the Subsidiary is party to or subject to the provisions of any
material injunction, judgment, decree or order of any court, regulatory body
administrative agency or other governmental body.

               4.9 Properties. Each of the Company and the Subsidiary has good
and marketable title to all the properties and assets reflected as owned by it
in the consolidated financial statements included in the Private Placement
Memorandum, subject to no lien, mortgage, pledge, charge or encumbrance of any
kind except (i) those, if any, reflected in such consolidated financial
statements, or (ii) those which are not material in amount and do not adversely
affect the use made and intended to be made of such property by the Company or
the Subsidiary. Each of the Company and the Subsidiary holds its leased
properties under valid and binding leases, with such exceptions as are not
materially significant in relation to its business taken as a whole.

               4.10 No Material Change. Since December 31, 2000 and except as
described in or specifically contemplated by the Private Placement Memorandum,
(i) the Company and the Subsidiary have not incurred any material liabilities or
obligations, indirect, or contingent, or entered into any material verbal or
written agreement or other transaction which is not in the ordinary course of
business other than a $500,000 milestone payment due to a collaborator and the
prepayment of approximately $3 million for the purchase of bulk drug product;
(ii) the Company and the Subsidiary have not sustained any material loss or
interference with its businesses or properties from fire, flood, windstorm,
accident or other calamity not covered by insurance; (iii) the Company and the
Subsidiary have not paid or declared any dividends or other distributions with
respect to its capital stock and neither the Company nor the Subsidiary is in
default in the payment of principal or interest on any outstanding debt
obligations; (iv) there has not been any change in the capital stock of the
Company or the Subsidiary other than the sale of the Company Shares hereunder
and shares or options issued pursuant to employee equity incentive plans or
purchase plans approved by the Company's Board of Directors, or indebtedness
material to the Company or the Subsidiary (other than in the ordinary course of
business and other than warrants to purchase 50,000 shares of the Company's
Common Stock); and (v) any other event or change that would have a Material
Adverse Effect.


                                      -6-
<PAGE>   7

               4.11 Intellectual Property.

                      (a) The Company has ownership or license or legal right to
        use all material patent, copyright, trade secret and trademark rights
        known by it to be necessary to the conduct of the business of the
        Company as now conducted (collectively, "Intellectual Property") other
        than Intellectual Property generally available on commercial terms from
        other sources.

                      (b) All material licenses or other material agreements
        under which (i) the Company is granted rights in Intellectual Property,
        other than Intellectual Property generally available on commercial terms
        from other sources, and (ii) the Company has granted rights to others in
        Intellectual Property owned or licensed by the Company, are in full
        force and effect and, to the knowledge of the Company, there is no
        material default by the Company or any other party thereto.

                      (c) The Company believes it has taken all steps required
        in accordance with sound business practice and business judgment to
        establish and preserve its ownership of all material copyright, trade
        secret and other proprietary rights with respect to its products and
        technology.

                      (d) To the knowledge of the Company, the present business,
        activities and products of the Company do not infringe any intellectual
        property of any other person, except where such infringement would not,
        individually or in the aggregate, have a Material Adverse Effect on the
        Company. Except as described in the Company's SEC Documents, no
        proceeding charging the Company with infringement of any adversely held
        Intellectual Property has been filed. To the knowledge of the Company,
        the Company is not making unauthorized use of any confidential
        information or trade secrets of any person. To the Company's knowledge,
        the activities of the Company or any of its employees on behalf of the
        Company do not violate any agreements or arrangements known to the
        Company which any such employees have with other persons, if any.

               4.12 Compliance. Neither the Company nor the Subsidiary have been
advised, nor has reason to believe, that it is not conducting its business in
compliance with all applicable laws, rules and regulations of the jurisdictions
in which it is conducting its business, including, without limitation, all
applicable local, state and federal environmental laws and regulations; except
where failure to be so in compliance would not have a Material Adverse Effect.

               4.13 Taxes. Each of the Company and the Subsidiary has filed all
necessary federal, state and foreign income and franchise tax returns and has
paid or accrued all taxes shown as due thereon, and neither the Company nor the
Subsidiary has knowledge of a tax deficiency which has been or might be asserted
or threatened against it which could have a Material Adverse Effect.

               4.14 Transfer Taxes. On the Closing Date, all stock transfer or
other taxes (other than income taxes) which are required to be paid in
connection with the sale and transfer of the Shares to be sold to the Purchaser
hereunder will be, or will have been, fully paid or


                                      -7-
<PAGE>   8

provided for by the Company and all laws imposing such taxes will be or will
have been complied with.

               4.15 Investment Company. The Company is not an "investment
company" or an "affiliated person" of, or "promoter" or "principal underwriter"
for an investment company, within the meaning of the Investment Company Act of
1940, as amended.

               4.16 Offering Materials. The Company has not distributed and will
not distribute prior to the Closing Date any offering material in connection
with the offering and sale of the Shares other than (i) the Private Placement
Memorandum or any amendment or supplement thereto, and (ii) other information
provided as contemplated by paragraph 1(a) of that certain Engagement Letter
between the Company and the Placement Agent dated May 6, 2001 (the "Engagement
Letter"). The Company has not in the past nor will it hereafter take any action
independent of the Placement Agent to sell, offer for sale or solicit offers to
buy any securities of the Company which would bring the offer, issuance or sale
of the Shares, as contemplated by this Agreement, within the provisions of
Section 5 of the Securities Act, unless such offer, issuance or sale was or
shall be within the exemptions of Section 4 of the Securities Act.

               4.17 Insurance. The Company maintains insurance of the types and
in the amounts that the Company reasonably believes is adequate for its
business, including, but not limited to, insurance covering all real and
personal property owned or leased by the Company against theft, damage,
destruction, acts of vandalism and all other risks customarily insured against
by similarly situated companies, all of which insurance is in full force and
effect.

               4.18 Contributions. The Company has not at any time since its
incorporation, directly or indirectly, (i) made any unlawful contribution to any
candidate for public office, or failed to disclose fully any contribution in
violation of law, or (ii) made any payment to any federal or state governmental
officer or official, or other person charged with similar public or quasi-public
duties, other than payments required or permitted by the laws of the United
States or any jurisdiction thereof.

               4.19 Additional Information. The information contained in the
following documents, which the Placement Agent has furnished to the Purchaser,
or will furnish prior to the Closing, does not include any untrue statement of a
material fact or omit to state any material fact required to be stated therein
or necessary to make the statements therein, in the light of the circumstances
in which they were made, not misleading, as of their respective final dates:

                      (a) the Company's Annual Report on Form 10-K for the year
        ended December 31, 2000;

                      (b) the draft Resale Registration Statement (as defined
        below);

                      (c) the Private Placement Memorandum, including all
        addenda and exhibits thereto (other than the Appendices); and


                                      -8-
<PAGE>   9

                      (d) all other documents, if any, filed by the Company with
        the Securities and Exchange Commission (the "Commission") since March
        31, 2001 pursuant to the reporting requirements of the Securities
        Exchange Act of 1934, as amended (the "Exchange Act").

               4.20 Legal Opinion. At the Closing, Cooley Godward LLP, counsel
to the Company, will deliver its legal opinion to the Placement Agent in the
form attached as Exhibit B to the Engagement Letter. Such opinion shall also
state that each of the Purchasers may rely thereon as though it was addressed
directly to such Purchaser.

               4.21 Intellectual Property Opinion. At the Closing, the Company's
in-house legal counsel will deliver a legal opinion to the Placement Agent in
the form attached as Exhibit C to the Engagement Letter. Such opinion shall also
state that each of the Purchasers may rely thereon as though it was addressed
directly to such Purchaser.

               4.22 Certificate. At the Closing, the Company will deliver to the
Purchaser a certificate executed by the Chairman of the Board or President and
the chief financial or accounting officer of the Company, dated the Closing
Date, in form and substance reasonably satisfactory to the Purchaser, to the
effect that the representations and warranties of the Company set forth in this
Section 4 were true and correct as of the date of this Agreement, and the
Company has complied in all material respects with all the agreements and
satisfied all the conditions herein on its part to be performed or satisfied on
or prior to such Closing Date.

               SECTION 5. Representations, Warranties and Covenants of the
Selling Stockholder. The Selling Stockholder represents, warrants and covenants
to the Company and to the Purchaser that:

               5.1 Due Execution and Delivery. Such Selling Stockholder has full
power and authority to enter into this Agreement and to carry out all the terms
and provisions hereof and thereof to be carried out by it. All authorizations
and consents necessary for the execution and delivery by such Selling
Stockholder of this Agreement have been given. This Agreement has been duly
authorized, executed and delivered by or on behalf of such Selling Stockholder
and this Agreement will a constitute legal, valid and binding obligation of such
Selling Stockholder, enforceable in accordance with its terms, except as
enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws affecting creditors' rights generally
and except as enforceability may be subject to general principles of equity
(regardless of whether such enforceability is considered in a proceeding in
equity or at law).

               5.2 Good Title. Such Selling Stockholder now has, and at the time
of delivery thereof hereunder will have, (i) good and marketable title to the
Shares to be sold by such Selling Stockholder hereunder, free and clear of all
encumbrances, and (ii) full legal right and power, and all authorizations and
approvals required by law, to sell, transfer and deliver the Selling Stockholder
Shares to the Purchasers hereunder and to make the representations, warranties
and agreements made by such Selling Stockholder herein.


                                      -9-
<PAGE>   10

               5.3 No Defaults. None of the execution, delivery or performance
of this Agreement, and the consummation of the transactions contemplated herein
or therein by such Selling Stockholder conflicts or will conflict with or
results or will result in any breach or violation of any of the terms or
provisions of, or constitute a default under, or result in the creation or
imposition of any encumbrance upon, any property or assets of such Selling
Stockholder pursuant to (i) the terms of any contract or other agreement to
which such Selling Stockholder is a party or by which it is bound or to which
any of its properties is subject, which conflict, breach, violation or default
would adversely affect such Selling Stockholder's ability to perform its
obligations hereunder; (ii) any statute, rule or regulation of any governmental
body having jurisdiction over such Selling Stockholder or any of its activities
or properties; or (iii) the terms of any judgment, decree or order of any
arbitration or governmental body having such jurisdiction.

               5.4 Consents. No consent, approval, authorization or order of, or
any filing or declaration with, any governmental body is required for the
consummation by such Selling Stockholder of the transactions on its part
contemplated herein, except such as have been obtained under the state
securities or Blue Sky laws.

               5.5 Material Adverse Information. The sale of the Shares proposed
to be sold by such Selling Stockholder is not prompted by such Selling
Stockholder's knowledge of any material adverse information concerning the
Company or its Subsidiary which is not set forth or described in the Private
Placement Memorandum or in the Company's SEC Documents.

               5.6 Material Information. On the date of the Private Placement
Memorandum, the information with respect to such Selling Stockholder included
therein did not contain any untrue statement of a material fact or omit to state
a material fact required to be stated therein or necessary in order to make the
statements therein not misleading.

               5.7 Company Representations and Warranties. Such Selling
Stockholder has no reason to believe that the representations and warranties of
the Company contained in Section 4 are not true and correct in all material
respects.

               SECTION 6. Representations, Warranties and Covenants of the
Purchaser.

                      (a) The Purchaser represents and warrants to, and
        covenants with, the Company and the Selling Stockholder that: (i) the
        Purchaser is knowledgeable, sophisticated and experienced in making, and
        is qualified to make, decisions with respect to investments in shares
        representing an investment decision like that involved in the purchase
        of the Shares, including investments in securities issued by the
        Company, and has requested, received, reviewed and considered all
        information it deems relevant in making an informed decision to purchase
        the Shares; (ii) the Purchaser is acquiring the number of Shares set
        forth in Section 2 above in the ordinary course of its business and for
        its own account for investment only and with no present intention of
        distributing any of such Shares or any arrangement or understanding with
        any other persons regarding the distribution of such Shares (this
        representation and warranty not limiting the Purchaser's


                                      -10-
<PAGE>   11

        right to sell pursuant to the Registration Statement or, other than with
        respect to any claims arising out of a breach of this representation and
        warranty, the Purchaser's right to indemnification under Section 8.3);
        (iii) the Purchaser will not, directly or indirectly, offer, sell,
        pledge, transfer or otherwise dispose of (or solicit any offers to buy,
        purchase or otherwise acquire or take a pledge of) any of the Shares
        except in compliance with the Securities Act and the Rules and
        Regulations; (iv) the Purchaser has completed or caused to be completed
        the Registration Statement Questionnaire attached hereto as part of
        Appendix I, for use in preparation of the Registration Statement, and
        the answers thereto are true and correct as of the date hereof and will
        be true and correct as of the effective date of the Registration
        Statement and the Purchaser will notify the Company immediately of any
        material change in any such information provided in the Registration
        Statement Questionnaire; (v) the Purchaser has, in connection with its
        decision to purchase the number of Shares set forth in Section 2 above,
        relied solely upon the Private Placement Memorandum and the documents
        included therein or incorporated by reference and the other Company
        information provided to the Purchaser by the Company and the
        representations and warranties of the Company contained herein; and (vi)
        the Purchaser is an "accredited investor" within the meaning of Rule
        501(a) of Regulation D promulgated under the Securities Act.

                      (b) The Purchaser understands that the Shares are being
        offered and sold to it in reliance upon specific exemptions from the
        registration requirements of Securities Act, the Rules and Regulations
        and state securities laws and that the Company is relying upon the truth
        and accuracy of, and the Purchaser's compliance with, the
        representations, warranties, agreements, acknowledgments and
        understandings of the Purchaser set forth herein in order to determine
        the availability of such exemptions and the eligibility of the Purchaser
        to acquire the Shares.

                      (c) The Purchaser agreed orally with the Placement Agent
        to keep confidential all information concerning this private placement.
        The Purchaser understands that the information contained in the Private
        Placement Memorandum is strictly confidential and proprietary to the
        Company and has been prepared from the Company's publicly available
        documents and other information and is being submitted to the Purchaser
        solely for such Purchaser's confidential use. The Purchaser agrees to
        use the information contained in the Private Placement Memorandum for
        the sole purpose of evaluating a possible investment in the Shares and
        the Purchaser hereby acknowledges that it is prohibited from reproducing
        or distributing the Private Placement Memorandum, this Purchase
        Agreement, or any other offering materials or other information provided
        by the Company in connection with the Purchaser's consideration of its
        investment in the Company, in whole or in part, or divulging or
        discussing any of their contents. Further, the Purchaser understands
        that the existence and nature of all conversations and presentations, if
        any, regarding the Company and this offering must be kept strictly
        confidential. The Purchaser understands that the federal securities laws
        impose restrictions on trading based on information regarding this
        offering. In addition, the Purchaser hereby acknowledges that
        unauthorized disclosure of information regarding this offering may cause
        the Company to violate Regulation FD.


                                      -11-
<PAGE>   12

                      (d) The Purchaser understands that its investment in the
        Shares involves a significant degree of risk and that the market price
        of the Common Stock has been volatile and that no representation is
        being made as to the future value of the Common Stock. The Purchaser has
        the knowledge and experience in financial and business matters as to be
        capable of evaluating the merits and risks of an investment in the
        Shares and has the ability to bear the economic risks of an investment
        in the Shares.

                      (e) The Purchaser understands that no United States
        federal or state agency or any other government or governmental agency
        has passed upon or made any recommendation or endorsement of the Shares.

                      (f) The Purchaser understands that, until such time as the
        Registration Statement has been declared effective or the Shares may be
        sold pursuant to Rule 144 under the Securities Act without any
        restriction as to the number of securities as of a particular date that
        can then be immediately sold, the Shares may bear a restrictive legend
        in substantially the following form (and a stop-transfer order may be
        placed against transfer of the certificates for the Shares):

                      "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT
                      BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
                      AMENDED. THE SECURITIES MAY NOT BE SOLD, TRANSFERRED OR
                      ASSIGNED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION
                      STATEMENT FOR THE SECURITIES UNDER SAID ACT, OR AN OPINION
                      OF COUNSEL, IN FORM, SUBSTANCE AND SCOPE REASONABLY
                      ACCEPTABLE TO THE COMPANY, THAT REGISTRATION IS NOT
                      REQUIRED UNDER SAID ACT OR UNLESS SOLD PURSUANT TO RULE
                      144 UNDER SAID ACT."

                      (g) The Purchaser's principal executive offices are in the
        jurisdiction set forth immediately below the Purchaser's name on the
        signature pages hereto.

                      (h) The Purchaser hereby covenants with the Company not to
        make any sale of the Shares without complying in all material respects
        with the provisions of this Agreement, and if applicable, without
        effectively causing the prospectus delivery requirement under the
        Securities Act to be satisfied, and the Purchaser acknowledges and
        agrees that such Shares are not transferable on the books of the Company
        unless the certificate submitted to the transfer agent evidencing the
        Shares is accompanied by a separate Purchaser's Certificate of
        Subsequent Sale: (i) in the form of Appendix II hereto, (ii) executed by
        an officer of, or other authorized person designated by, the Purchaser,
        and (iii) to the effect that (A) the Shares have been sold in accordance
        with the Registration Statement, the Securities Act and any applicable
        state securities or blue sky laws and (B), if applicable, the
        requirement of delivering a current prospectus has been satisfied. The
        Purchaser acknowledges that there may occasionally be times when the
        Company must suspend the use of the prospectus forming a part of the
        Registration Statement (a "Suspension") until such time as an amendment
        to the Registration Statement has been filed by the Company and


                                      -12-
<PAGE>   13

        declared effective by the Commission, or until such time as the Company
        has filed an appropriate report with the Commission pursuant to the
        Exchange Act. The Purchaser hereby covenants that it will not sell any
        Shares pursuant to said prospectus during the period commencing at the
        time at which the Company gives the Purchaser written notice of the
        Suspension of the use of said prospectus and ending at the time the
        Company gives the Purchaser written notice that the Purchaser may
        thereafter effect sales pursuant to said prospectus, except as
        permitted in the second paragraph of Section 8.2 of this Agreement.

                      (i) The Purchaser further represents and warrants to, and
        covenants with, the Company that (i) the Purchaser has full right,
        power, authority and capacity to enter into this Agreement and to
        consummate the transactions contemplated hereby and has taken all
        necessary action to authorize the execution, delivery and performance of
        this Agreement, and (ii) upon the execution and delivery of this
        Agreement, this Agreement shall constitute a legal, valid and binding
        obligation of the Purchaser, enforceable in accordance with its terms,
        except as enforceability may be limited by applicable bankruptcy,
        insolvency, reorganization, moratorium or similar laws affecting
        creditors' and contracting parties' rights generally and except as
        enforceability may be subject to general principles of equity
        (regardless of whether such enforceability is considered in a proceeding
        in equity or at law) and except as the indemnification agreements of the
        Purchaser in Section 8.3 hereof may be legally unenforceable.

               SECTION 7. Survival of Representations, Warranties and
Agreements. Notwithstanding any investigation made by any party to this
Agreement or by the Placement Agent, all covenants, agreements, representations
and warranties made by the Company, the Selling Stockholder and the Purchaser
herein and in the certificates for the Shares delivered pursuant hereto shall
survive the execution of this Agreement, the delivery to the Purchaser of the
Shares being purchased and the payment therefor.

               SECTION 8. Registration of the Shares; Compliance with the
Securities Act.

               8.1 Registration Procedures and Expenses. The Company shall:

                      (a) subject to receipt of necessary information from the
        Purchasers, as promptly as practicable, but in no event later than 10
        days after the date that the Agreements are executed, file with the
        Commission the Registration Statement on Form S-3 relating to the sale
        of the Shares by the Purchaser and the Other Purchasers from time to
        time on the Nasdaq National Market or the facilities of any national
        securities exchange on which the Common Stock is then traded or in
        privately-negotiated transactions;

                      (b) use its reasonable efforts, subject to receipt of
        necessary information from the Purchasers, to cause the Commission to
        notify the Company of the Commission's willingness to declare the
        Registration Statement effective within 60 days after the Registration
        Statement is filed by the Company;


                                      -13-
<PAGE>   14

                      (c) promptly prepare and file with the Commission such
        amendments and supplements to the Registration Statement and the
        prospectus used in connection therewith as may be necessary to keep the
        Registration Statement effective until the earlier of (i) two years
        after the effective date of the Registration Statement; (ii) the date on
        which the Shares may be resold by the Purchasers without registration by
        reason of Rule 144(k) under the Securities Act or any other rule of
        similar effect; or (iii) such time as all Shares purchased by such
        Purchaser under this Agreement have been sold.

                      (d) furnish to the Purchaser with respect to the Shares
        registered under the Registration Statement (and to each underwriter, if
        any, of such Shares) such number of copies of prospectuses and such
        other documents as the Purchaser may reasonably request, in order to
        facilitate the public sale or other disposition of all or any of the
        Shares by the Purchaser; provided, however, that the obligation of the
        Company to deliver copies of prospectuses to the Purchaser shall be
        subject to the receipt by the Company of reasonable assurances from the
        Purchaser that the Purchaser will comply with the applicable provisions
        of the Securities Act and of such other securities or blue sky laws as
        may be applicable in connection with any use of such prospectuses;

                      (e) file documents required of the Company for normal blue
        sky clearance in states specified in writing by the Purchaser; provided,
        however, that the Company shall not be required to qualify to do
        business or consent to service of process in any jurisdiction in which
        it is not now so qualified or has not so consented; and

                      (f) bear all expenses in connection with the procedures in
        paragraphs (a) through (e) of this Section 8.1 and the registration of
        the Shares pursuant to the Registration Statement, other than fees and
        expenses, if any, of counsel or other advisers to the Purchaser or the
        Other Purchasers or underwriting discounts, brokerage fees and
        commissions incurred by the Purchaser or the Other Purchasers, if any.

               The Company understands that the Purchaser disclaims being an
underwriter, but the Purchaser being deemed an underwriter shall not relieve the
Company of any obligations it has hereunder; provided, however, that if the
Company receives notification from the Commission that the Purchaser or any
Other Purchaser is deemed an underwriter, then the 60 day period referenced in
the second paragraph of Section 3 and in Section 8.1(b) above shall be extended
to 90 days. A draft of the proposed form of the Registration Statement is
included in the Private Placement Memorandum and a questionnaire related thereto
to be completed by the Purchaser is attached hereto as Appendix I.

               8.2 Transfer of Shares After Registration. The Purchaser agrees
that it will not effect any disposition of the Shares or its right to purchase
the Shares that would constitute a sale within the meaning of the Securities
Act, except as contemplated in the Registration Statement referred to in Section
8.1, and that it will promptly notify the Company of any changes in the
information set forth in the Registration Statement regarding the Purchaser or
its plan of distribution.

               Notwithstanding any other provisions of this Agreement, the
Purchaser shall not be prohibited from selling Shares under the Registration
Statement as a result of Suspensions on more than two occasions of not more
than 30 days each in any twelve month period, unless, in the good faith
judgment of the Company's Board of Directors, upon advice of counsel, the sale
of Shares under the Registration Statement in reliance on this paragraph would
be reasonably likely to cause a violation of the Securities Act or the Exchange
Act and result in potential liability to the Company.

               8.3 Indemnification. For the purpose of this Section 8.3:


                                      -14-
<PAGE>   15

                (i)     the term "Purchaser/Affiliate" shall mean any affiliates
                        of the Purchaser and any person who controls the
                        Purchaser or any affiliate of the Purchaser within the
                        meaning of Section 15 of the Securities Act or Section
                        20 of the Exchange Act; and

                (ii)    the term "Registration Statement" shall include any
                        final prospectus, exhibit, supplement or amendment
                        included in or relating to, and any document
                        incorporated by reference in, the Registration Statement
                        referred to in Section 8.1.

               (a) The Company agrees to indemnify and hold harmless each of the
        Purchasers and each Purchaser/Affiliate, against any losses, claims,
        damages, liabilities or expenses, joint or several, to which such
        Purchasers or such Purchaser/Affiliates may become subject, under the
        Securities Act, the Exchange Act, or any other federal or state
        statutory law or regulation, or at common law or otherwise (including in
        settlement of any claims or litigation, if such settlement is effected
        with the written consent of the Company), insofar as such losses,
        claims, damages, liabilities or expenses (or actions in respect thereof
        as contemplated below) arise out of or are based upon any untrue
        statement or alleged untrue statement of any material fact contained in
        the Registration Statement, including the prospectus, financial
        statements and schedules, and all other documents filed as a part
        thereof, as amended at the time of effectiveness of the Registration
        Statement, including any information deemed to be a part thereof as of
        the time of effectiveness pursuant to paragraph (b) of Rule 430A, or
        pursuant to Rule 434, of the Rules and Regulations, or the prospectus,
        in the form first filed with the Commission pursuant to Rule 424(b) of
        the Rules and Regulations, or filed as part of the Registration
        Statement at the time of effectiveness if no Rule 424(b) filing is
        required (the "Prospectus"), or any amendment or supplement thereto, or
        arise out of or are based upon the omission or alleged omission to state
        in any of them a material fact required to be stated therein or
        necessary to make the statements in the Registration Statement or any
        amendment or supplement thereto not misleading or in the Prospectus or
        any amendment or supplement thereto not misleading in the light of the
        circumstances under which they were made, or arise out of or are based
        in whole or in part on any inaccuracy in the representations and
        warranties of the Company contained in this Agreement, or any failure of
        the Company to perform its obligations hereunder or under law, and will
        reimburse each Purchaser and each such Purchaser/Affiliate for any legal
        and other expenses as such expenses are reasonably incurred by such
        Purchaser or such Purchaser/Affiliate in connection with investigating,
        defending, settling, compromising or paying any such loss, claim,
        damage, liability, expense or action; provided, however, that the
        Company will not be liable in any such case to the extent that any such
        loss, claim, damage, liability or expense arises out of or is based upon
        (i) an untrue statement or alleged untrue statement or omission or
        alleged omission made in the Registration Statement, the Prospectus or
        any amendment or supplement thereto in reliance upon and in conformity
        with written information furnished to the Company by or on behalf of the
        Purchaser expressly for use therein, or (ii) the failure of such
        Purchaser to comply with the covenants and agreements contained in
        Sections 6(h) or 8.2 hereof respecting the sale


                                      -15-
<PAGE>   16

        of the Shares, or (iii) the inaccuracy of any representations made by
        such Purchaser herein or (iv) any statement or omission in any
        Prospectus or any amendment or supplement thereto that is corrected in
        any subsequent Prospectus or any amendment or supplement thereto that
        was delivered to the Purchaser prior to the pertinent sale or sales by
        the Purchaser.

               (b) Each Purchaser will severally, but not jointly, indemnify and
        hold harmless the Company and the Selling Stockholder, each of the
        Company's directors, each of the Company's officers who signed the
        Registration Statement and each person, if any, who controls the Company
        within the meaning of Section 15 of the Securities Act or Section 20 of
        the Exchange Act or any Selling Stockholder, against any losses, claims,
        damages, liabilities or expenses to which the Company, each of its
        directors, each of its officers who signed the Registration Statement,
        any Selling Stockholder or any of their respective controlling persons
        may become subject, under the Securities Act, the Exchange Act, or any
        other federal or state statutory law or regulation, or at common law or
        otherwise (including in settlement of any claim or litigation, if such
        settlement is effected with the written consent of such Purchaser)
        insofar as such losses, claims, damages, liabilities or expenses (or
        actions in respect thereof as contemplated below) arise out of or are
        based upon (i) any failure to comply with the covenants and agreements
        contained in Sections 6(h) or 8.2 hereof respecting the sale of the
        Shares or (ii) the inaccuracy of any representation made by such
        Purchaser herein or (iii) any untrue or alleged untrue statement of any
        material fact contained in the Registration Statement, the Prospectus,
        or any amendment or supplement thereto, or arise out of or are based
        upon the omission or alleged omission to state therein a material fact
        required to be stated therein or necessary to make the statements in the
        Registration Statement or any amendment or supplement thereto not
        misleading or in the Prospectus or any amendment or supplement thereto
        not misleading in the light of the circumstances under which they were
        made, in each case to the extent, but only to the extent, that such
        untrue statement or alleged untrue statement or omission or alleged
        omission was made in the Registration Statement, the Prospectus, or any
        amendment or supplement thereto, in reliance upon and in conformity with
        written information furnished to the Company by the Purchaser expressly
        for use therein, and will reimburse the Company and the Selling
        Stockholder, each of the Company's directors, each of its officers who
        signed the Registration Statement or controlling person for any legal
        and other expense reasonably incurred by the Company and the Selling
        Stockholder, each of the Company's directors, each of its officers who
        signed the Registration Statement or controlling person in connection
        with investigating, defending, settling, compromising or paying any such
        loss, claim, damage, liability, expense or action. Notwithstanding any
        other provisions of this Section 8.3(b), no Purchaser shall be required
        to indemnify any party in excess of the gross proceeds paid by such
        Purchaser for Shares purchased pursuant to its respective Agreement.

               (c) The Selling Stockholder will severally indemnify and hold
        harmless each Purchaser, each Purchaser/Affiliate, the Company, each of
        its directors and each of its officers who signed the Registration
        Statement and each person, if any, who controls the Company within the
        meaning of Section 15 of the Securities Act or Section 20 of the
        Exchange Act, against any losses, claims, damages, liabilities or
        expenses to which the Company, each of its directors, each of its
        officers who signed the Registration Statement


                                      -16-
<PAGE>   17

        or controlling person may become subject, under the Securities Act, the
        Exchange Act, or any other federal or state statutory law or regulation,
        or at common law or otherwise (including the settlement of any claim or
        litigation, if such settlement is effected with the written consent of
        such Selling Stockholder) insofar as such losses, claims, damages,
        liabilities or expenses (or actions in respect thereof as contemplated
        below) arise out of, or are based upon (i) any failure to comply with
        the covenants and agreements of such Selling Stockholder contained in
        the Agreements or (ii) the inaccuracy of any representation made by such
        Selling Stockholder in the Agreements or (iii) any untrue or alleged
        untrue statement of any material fact contained in the Registration
        Statement, the Prospectus, or any amendment or supplement thereto, or
        arise out of or are based upon the omission or alleged omission to state
        therein a material fact required to be stated therein or necessary to
        make the statements in the Registration Statement or any amendment or
        supplement thereto not misleading or in the Prospectus or any amendment
        or supplement thereto not misleading in the light of the circumstances
        under which they were made, in each case to the extent, but only to the
        extent, that such untrue statement or alleged untrue statement or
        omission or alleged omission was made in the Registration Statement, the
        Prospectus, or any amendment or supplement thereto, in reliance upon and
        in conformity with written information furnished to the Company by such
        Selling Stockholder expressly for use therein.

               (d) Promptly after receipt by an indemnified party under this
        Section 8.3 of notice of the threat or commencement of any action, such
        indemnified party will, if a claim in respect thereof is to be made
        against an indemnifying party under this Section 8.3 promptly notify the
        indemnifying party in writing thereof; but the omission so to notify the
        indemnifying party will not relieve it from any liability which it may
        have to any indemnified party for contribution or otherwise than under
        the indemnity agreement contained in this Section 8.3 or to the extent
        it is not prejudiced as a result of such failure. In case any such
        action is brought against any indemnified party and such indemnified
        party seeks or intends to seek indemnity from an indemnifying party, the
        indemnifying party will be entitled to participate in, and, to the
        extent that it may wish, jointly with all other indemnifying parties
        similarly notified, to assume the defense thereof with counsel
        reasonably satisfactory to such indemnified party; provided, however, if
        the defendants in any such action include both the indemnified party and
        the indemnifying party and, based upon the advice of such indemnified
        party's counsel, the indemnified party shall have reasonably concluded
        that there may be a conflict of interest between the positions of the
        indemnifying party and the indemnified party in conducting the defense
        of any such action or that there may be legal defenses available to it
        and/or other indemnified parties which are different from or additional
        to those available to the indemnifying party, the indemnified party or
        parties shall have the right to select separate counsel to assume such
        legal defenses and to otherwise participate in the defense of such
        action on behalf of such indemnified party or parties. Upon receipt of
        notice from the indemnifying party to such indemnified party of its
        election so to assume the defense of such action and approval by the
        indemnified party of counsel, the indemnifying party will not be liable
        to such indemnified party under this Section 8.3 for any legal or other
        expenses subsequently incurred by such indemnified party in connection
        with the defense thereof unless (i) the


                                      -17-
<PAGE>   18

        indemnified party shall have employed such counsel in connection with
        the assumption of legal defenses in accordance with the proviso to the
        preceding sentence (it being understood, however, that the indemnifying
        party shall not be liable for the expenses of more than one separate
        counsel, representing the indemnified parties who are parties to such
        action, plus local counsel, if appropriate) or (ii) the indemnifying
        party shall not have employed counsel reasonably satisfactory to the
        indemnified party to represent the indemnified party within a reasonable
        time after notice of commencement of action, in each of which cases the
        reasonable fees and expenses of counsel shall be at the expense of the
        indemnifying party.

               (e) If the indemnification provided for in this Section 8.3 is
        required by its terms but is for any reason held to be unavailable to or
        otherwise insufficient to hold harmless an indemnified party under
        paragraphs (a), (b) or (c) of this Section 8.3 in respect to any losses,
        claims, damages, liabilities or expenses referred to herein, then each
        applicable indemnifying party shall contribute to the amount paid or
        payable by such indemnified party as a result of any losses, claims,
        damages, liabilities or expenses referred to herein (i) in such
        proportion as is appropriate to reflect the relative benefits received
        by the Company, the Selling Stockholder and the Purchaser from the
        placement of the Common Stock contemplated by this Agreement or (ii) if
        the allocation provided by clause (i) above is not permitted by
        applicable law, in such proportion as is appropriate to reflect not only
        the relative benefits referred to in clause (i) above but the relative
        fault of the Company, the Selling Stockholder and the Purchaser in
        connection with the statements or omissions or inaccuracies in the
        representations and warranties in this Agreement that resulted in such
        losses, claims, damages, liabilities or expenses, as well as any other
        relevant equitable considerations. The relative benefits received by the
        Company and the Selling Stockholder, respectively, on the one hand and
        each Purchaser on the other shall be deemed to be in the same proportion
        as the amount paid by such Purchaser to the Company and the Selling
        Stockholder, respectively, pursuant to this Agreement for the Shares
        purchased by such Purchaser that were sold pursuant to the Registration
        Statement bears to the difference (the "Difference") between the amount
        such Purchaser paid for the Shares that were sold pursuant to the
        Registration Statement and the amount received by such Purchaser from
        such sale. The relative fault of the Company and the Selling
        Stockholder, respectively, on the one hand and each Purchaser on the
        other shall be determined by reference to, among other things, whether
        the untrue or alleged statement of a material fact or the omission or
        alleged omission to state a material fact or the inaccurate or the
        alleged inaccurate representation and/or warranty relates to information
        supplied by the Company, by such Selling Stockholder or by such
        Purchaser and the parties' relative intent, knowledge, access to
        information and opportunity to correct or prevent such statement or
        omission. The amount paid or payable by a party as a result of the
        losses, claims, damages, liabilities and expenses referred to above
        shall be deemed to include, subject to the limitations set forth in
        paragraph (d) of this Section 8.3, any legal or other fees or expenses
        reasonably incurred by such party in connection with investigating or
        defending any action or claim. The provisions set forth in paragraph (d)
        of this Section 8.3 with respect to the notice of the threat or
        commencement of any action shall apply if a claim for contribution is to
        be


                                      -18-
<PAGE>   19

        made under this paragraph (e); provided, however, that no additional
        notice shall be required with respect to any threat or action for which
        notice has been given under paragraph (d) for purposes of
        indemnification. The Company, the Selling Stockholder and each Purchaser
        agree that it would not be just and equitable if contribution pursuant
        to this Section 8.3 were determined solely by pro rata allocation (even
        if the Purchaser were treated as one entity for such purpose) or by any
        other method of allocation which does not take account of the equitable
        considerations referred to in this paragraph. Notwithstanding the
        provisions of this Section 8.3, no Purchaser shall be required to
        contribute any amount in excess of the amount by which the Difference
        exceeds the amount of any damages that such Purchaser has otherwise been
        required to pay by reason of such untrue or alleged untrue statement or
        omission or alleged omission. Notwithstanding the provisions of this
        Section 8.3, no Selling Stockholder shall be required to contribute any
        amount in excess of the gross proceeds received by such Selling
        Stockholder for the sales of Selling Stockholder Shares under the
        Agreements. No person guilty of fraudulent misrepresentation (within the
        meaning of Section 11(f) of the Securities Act) shall be entitled to
        contribution from any person who was not guilty of such fraudulent
        misrepresentation. The Purchasers' obligations to contribute pursuant to
        this Section 8.3 are several and not joint.

               8.4 Termination of Conditions and Obligations. The conditions
precedent imposed by Section 6 or this Section 8 upon the transferability of the
Shares shall cease and terminate as to any particular number of the Shares upon
the passage of two years from the effective date of the Registration Statement
covering such Shares or at such time as an opinion of counsel satisfactory in
form and substance to the Company shall have been rendered to the effect that
such conditions are not necessary in order to comply with the Securities Act.

               8.5 Information Available. So long as the Registration Statement
is effective covering the resale of Shares owned by the Purchaser, the Company
will furnish to the Purchaser:

                      (a) as soon as practicable after available one copy of (i)
        its Annual Report to Stockholders (which Annual Report shall contain
        financial statements audited in accordance with generally accepted
        accounting principles by a national firm of certified public
        accountants), (ii) if not included in substance in the Annual Report to
        Stockholders, upon the request of the Purchaser, its Annual Report on
        Form 10-K, (iii) upon the request of the Purchaser, its Quarterly
        Reports on Form 10-Q, (iv) upon the request of the Purchaser, its
        Current Reports on Form 8-K, and (v) a full copy of the particular
        Registration Statement covering the Shares (the foregoing, in each case,
        excluding exhibits);

                      (b) upon the request of the Purchaser, all exhibits
        excluded by the parenthetical to subparagraph (a)(v) of this Section
        8.5; and

                      (c) upon the request of the Purchaser, a reasonable number
        of copies of the prospectuses to supply to any other party requiring
        such prospectuses;


                                      -19-
<PAGE>   20

and the Company, upon the reasonable request of the Purchaser, will meet with
the Purchaser or a representative thereof at the Company's headquarters to
discuss information relevant for disclosure in the Registration Statement
covering the Shares and will otherwise cooperate with any Purchaser conducting
an investigation for the purpose of reducing or eliminating such Purchaser's
exposure to liability under the Securities Act, including the reasonable
production of information at the Company's headquarters, subject to appropriate
confidentiality limitations.

               SECTION 9. Broker's Fee. The Purchaser acknowledges that the
Company and the Selling Stockholder intend to pay to the Placement Agent a fee
in respect of the sale of the Shares to the Purchaser. Each of the parties
hereto hereby represents that, on the basis of any actions and agreements by it,
there are no other brokers or finders entitled to compensation in connection
with the sale of the Shares to the Purchaser.

               SECTION 10. Notices. All notices, requests, consents and other
communications hereunder shall be in writing, shall be mailed by first-class
registered or certified airmail, confirmed facsimile or nationally recognized
overnight express courier postage prepaid, and shall be deemed given when so
mailed and shall be delivered as addressed as follows:

                        (a)     if to the Company, to:

                                Amylin Pharmaceuticals, Inc.
                                9373 Towne Centre Drive
                                San Diego, California
                                Attention:     Joseph C. Cook, Jr.
                                               Chief Executive Officer
                                Facsimile:     (858) 552-2212

                                with a copy to:

                                Cooley Godward LLP
                                4365 Executive Drive, Suite 1100
                                San Diego, CA 92121
                                Attention:     Thomas A. Coll, Esq.
                                Facsimile:     (858) 453-3555

                                or to such other person at such other place as
                                the Company shall designate to the Purchaser in
                                writing; and

                        (b)     if to the Purchaser, at its address as set forth
                                at the end of this Agreement, or at such other
                                address or addresses as may have been furnished
                                to the Company in writing.

                        (c)     if to the Selling Stockholder, at the addresses
                                set forth in Exhibit A-1 hereto.


                                      -20-
<PAGE>   21

               SECTION 11. Changes. This Agreement may not be modified or
amended except pursuant to an instrument in writing signed by the Company and
the Purchaser.

               SECTION 12. Headings. The headings of the various sections of
this Agreement have been inserted for convenience of reference only and shall
not be deemed to be part of this Agreement.

               SECTION 13. Severability. In case any provision contained in this
Agreement should be invalid, illegal or unenforceable in any respect, the
validity, legality and enforceability of the remaining provisions contained
herein shall not in any way be affected or impaired thereby.

               SECTION 14. Governing Law. This Agreement shall be governed by
and construed in accordance with the laws of the State of New York and the
federal law of the United States of America.

               SECTION 15. Counterparts. This Agreement may be executed in two
or more counterparts, each of which shall constitute an original, but all of
which, when taken together, shall constitute but one instrument, and shall
become effective when one or more counterparts have been signed by each party
hereto and delivered to the other parties. Facsimile signatures shall be deemed
original signatures.

               SECTION 16. Entire Agreement. This Agreement and the instruments
referenced herein contain the entire understanding of the parties with respect
to the matters covered herein and therein and, except as specifically set forth
herein or therein, neither the Company nor the Purchaser makes any
representation, warranty, covenant or undertaking with respect to such matters.

               SECTION 17. Third Party Beneficiaries. This Agreement is intended
for the benefit of the parties hereto and their respective permitted successors
and assigns, and is not for the benefit of, nor may any provision hereof be
enforced by, any other person.

               SECTION 18. Confidential Disclosure Agreement. Notwithstanding
any provision of this Agreement to the contrary, any confidential disclosure
agreement previously executed by the Company and the Purchaser in connection
with the transactions contemplated by this Agreement shall remain in full force
and effect in accordance with its terms following the execution of this
Agreement and the consummation of the transactions contemplated hereby.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                      -21-
<PAGE>   22

               IN WITNESS WHEREOF, the parties hereto have caused this Agreement
to be executed by their duly authorized representatives as of the day and year
first above written.

                                            AMYLIN PHARMACEUTICALS, INC.


                                            By:_________________________________
                                               Name:
                                               Title:


                                            SELLING STOCKHOLDER


                                            ____________________________________
                                            Allen Andersson


                      Print or Type:        Name of Purchaser
                                            (Individual or Institution):


                                            ____________________________________


                                            Name of Individual representing
                                            Purchaser (if an Institution):


                                            ____________________________________


                                            Title of Individual representing
                                            Purchaser (if an Institution):

                                            ____________________________________



                                      -22-
<PAGE>   23

Signature by:                               Individual Purchaser or Individual
                                            representing Purchaser:

                                            ____________________________________



                                            Address:    ________________________
                                            Telephone:  ________________________
                                            Facsimile:  ________________________





                                      -23-
<PAGE>   24

                     SUMMARY INSTRUCTION SHEET FOR PURCHASER

                   (to be read in conjunction with the entire
                        Purchase Agreement which follows)

A.      Complete the following items on BOTH Purchase Agreements:

        1.      Pages 22-23 - Signature:

                (i)     Name of Purchaser (Individual or Institution)

                (ii)    Name of Individual representing Purchaser (if an
                        Institution)

                (iii)   Title of Individual representing Purchaser (if an
                        Institution)

                (iv)    Signature of Individual Purchaser or Individual
                        representing Purchaser

        2.      Appendix I - Stock Certificate Questionnaire/Registration
                Statement Questionnaire:

                Provide the information requested by the Stock Certificate
                Questionnaire and the Registration Statement Questionnaire.

        3.      Return BOTH properly completed and signed Purchase Agreements
                including the properly completed Appendix I to:

                      Lehman Brothers Inc.
                      Three World Financial Center
                      New York, NY  10285
                      Attention: Peter Bennett

B.      Instructions regarding the transfer of funds for the purchase of Shares
        will be sent by facsimile to the Purchaser by the Placement Agent at a
        later date.

C.      Upon the resale of the Shares by the Purchasers after the Registration
        Statement covering the Shares is effective, as described in the Purchase
        Agreement, the Purchaser:

                (i)     must deliver a current prospectus of the Company to the
                        buyer (prospectuses must be obtained from the Company at
                        the Purchaser's request); and

                (ii)    must send a letter in the form of Appendix II to the
                        Company so that the Shares may be properly transferred.



<PAGE>   25

                                                                      Appendix I
                                                                    (one of two)

AMYLIN PHARMACEUTICALS, INC.
STOCK CERTIFICATE QUESTIONNAIRE



               Pursuant to Section 3 of the Agreement, please provide us with
the following information:

1.         The exact name that your Shares are to be registered in (this is the
           name that will appear on your stock certificate(s)). You may
           use a nominee name if appropriate:         __________________________

2.         The relationship between the Purchaser of the
           Shares and the Registered Holder listed in
           response to item 1 above:                  __________________________

3.         The mailing address of the Registered Holder
           listed in response to item 1 above:        __________________________
                                                      __________________________
                                                      __________________________
                                                      __________________________

4.         The Social Security Number or Tax
           Identification Number of the Registered Holder
           listed in response to item 1 above:        __________________________



<PAGE>   26

                                                                      Appendix I
                                                                    (two of two)

                          AMYLIN PHARMACEUTICALS, INC.
                      REGISTRATION STATEMENT QUESTIONNAIRE

               In connection with the preparation of the Registration Statement,
please provide us with the following information:

1.  Pursuant to the "Selling Stockholder" section of the Registration Statement,
    please state your or your organization's name exactly as it should appear in
    the Registration Statement:



2.  Please provide the number of shares that you or your organization will own
    immediately after Closing, including those Shares purchased by you or your
    organization pursuant to this Purchase Agreement and those shares purchased
    by you or your organization through other transactions:



3.  Have you or your organization had any position, office or other material
    relationship within the past three years with the Company or its affiliates?

                      _____ Yes         _____ No

               If yes, please indicate the nature of any such relationships
below:

               _________________________________________________________________

               _________________________________________________________________

               _________________________________________________________________

4.  Are you (i) an NASD Member (see definition), (ii) a Controlling (see
    definition) shareholder of an NASD Member, (iii) a Person Associated with a
    Member of the NASD (see definition), or (iv) an Underwriter or a Related
    Person (see definition) with respect to the proposed offering; or (b) do you
    own any shares or other securities of any NASD Member not purchased in the
    open market; or (c) have you made any outstanding subordinated loans to any
    NASD Member?

               Answer:  [ ] Yes    [ ] No  If "yes," please describe below

               _________________________________________________________________

               _________________________________________________________________

               _________________________________________________________________



<PAGE>   27

               NASD Member. The term "NASD member" means either any broker or
dealer admitted to membership in the National Association of Securities Dealers,
Inc. ("NASD"). (NASD Manual, By-laws Article I, Definitions)

               Control. The term "control" (including the terms "controlling,"
"controlled by" and "under common control with") means the possession, direct or
indirect, of the power, either individually or with others, to direct or cause
the direction of the management and policies of a person, whether through the
ownership of voting securities, by contract, or otherwise. (Rule 405 under the
Securities Act of 1933, as amended)

               Person Associated with a member of the NASD. The term "person
associated with a member of the NASD" means every sole proprietor, partner,
officer, director, branch manager or executive representative of any NASD
Member, or any natural person occupying a similar status or performing similar
functions, or any natural person engaged in the investment banking or securities
business who is directly or indirectly controlling or controlled by a NASD
Member, whether or not such person is registered or exempt from registration
with the NASD pursuant to its bylaws. (NASD Manual, By-laws Article I,
Definitions)

               Underwriter or a Related Person. The term "underwriter or a
related person" means, with respect to a proposed offering, underwriters,
underwriters' counsel, financial consultants and advisors, finders, members of
the selling or distribution group, and any and all other persons associated with
or related to any of such persons. (NASD Interpretation)



<PAGE>   28

                                                                     APPENDIX II

Attention:

                   PURCHASER'S CERTIFICATE OF SUBSEQUENT SALE

      The undersigned, [an officer of, or other person duly authorized by]

________________________________________________________________________
         [fill in official name of individual or institution]

hereby certifies that he/she [said institution] is the Purchaser of

the shares evidenced by the attached certificate, and as such,

sold such shares on _______________ in accordance with
                        [date]

Registration Statement number _____________________________________
                               [fill in the number of or otherwise

________________________________ and the requirement of delivering a
identify Registration Statement]

current prospectus by the Company has been complied with in connection with such
sale.

Print or Type:

        Name of Purchaser
        (Individual or
        Institution):        ______________________

        Name of Individual
        representing
        Purchaser (if an
        Institution)         ______________________

        Title of Individual
        representing
        Purchaser (if an
        Institution):        ______________________

        Signature by:
        Individual Purchaser
        or Individual repre-
        senting Purchaser:   ______________________



<PAGE>   29

                                                                     Exhibit A-1



                               SELLING STOCKHOLDER

<TABLE>
<CAPTION>
Name                  Address for Notices           Number of Shares to be Sold
----                  -------------------           ---------------------------
<S>                   <C>                           <C>
Allen Andersson       7501 Cayuga Avenue                   600,000
                      Bethesda, MD  20817

                                                    Total: 600,000
</TABLE>



<PAGE>   30

                             SCHEDULE OF PURCHASERS

<TABLE>
<CAPTION>
                                                                       Number of Shares      Aggregate
                           Name                                            Purchased           Price
                           ----                                        ----------------     -----------
<S>                                                                    <C>                  <C>
Vaughn D. Bryson                                                              10,000        $   100,000
Clipperbay & Co., as nominee for SMALLCAP World Fund, Inc.                   450,000        $ 4,500,000
Framlington Investment Management                                            460,000        $ 4,600,000
Peter Hecht                                                                   15,000        $   150,000
BioCentive Limited                                                           100,000        $ 1,000,000
Deerfield Partners, L.P.                                                     105,900        $ 1,059,000
Deerfield International Limited                                               44,100        $   441,000
Caduceus Capital II, LP                                                       75,000        $   750,000
Winchester Global Trust Company Limited, as trustee for
  Caduceus Capital Trust                                                     145,000        $ 1,450,000
PW Eucalyptus Fund Ltd.                                                       10,000        $   100,000
PW Eucalyptus Fund LLC                                                       170,000        $ 1,700,000
Pequot Healthcare Fund, L.P.                                                 627,040        $ 6,270,400
Pequot Healthcare Institutional Fund, L.P.                                   180,320        $ 1,803,200
Pequot Healthcare Offshore Fund, Inc.                                        792,640        $ 7,926,400
CLSP, LP                                                                     261,508        $ 2,615,080
CLSP II, LP                                                                   37,976        $   379,760
CLSP SBS-I, LP                                                                76,762        $   767,620
CLSP SBS-II, LP                                                               38,074        $   380,740
CLSP Overseas Ltd.                                                            85,680        $   856,800
Morgan Stanley & Co., as prime broker for Merlin BioMed Int'l, Ltd.          184,000        $ 1,840,000
Morgan Stanley & Co., as prime broker for Merlin BioMed, L.P.                128,000        $ 1,280,000
Morgan Stanley & Co., as prime broker for Merlin BioMed II, L.P.              52,000        $   520,000
Morgan Stanley & Co., as prime broker for Merlin BioMed III, L.P.             28,000        $   280,000
Morgan Stanley & Co., as prime broker for TAIB Funds, Ltd.                     8,000        $    80,000
                                                                           ---------        -----------
TOTALS                                                                     4,085,000        $40,850,000
                                                                           =========        ===========
</TABLE>