Document:

<PAGE>

                                                                   Exhibit 10.34

          FIRST AMENDMENT TO COPROMOTION AND CODEVELOPMENT AGREEMENT

     This FIRST AMENDMENT TO COPROMOTION AND CODEVELOPMENT AGREEMENT (this
"Amendment") is made this 17th day of December, 2001, made by and between
ViroPharma Incorporated, a Delaware corporation (hereinafter "ViroPharma"), with
offices located at 405 Eagleview Boulevard, Exton, PA 19341, and Aventis
Pharmaceuticals Inc., a Delaware corporation (hereinafter "Aventis"), with
offices located at Route 202-206, P.O. Box 6800, Bridgewater, New Jersey 08807.

     WHEREAS, ViroPharma and Aventis are parties to that certain Copromotion and
Codevelopment Agreement dated as of September 9, 2001 (the "Agreement"); and

     WHEREAS,  ViroPharma and Aventis wish to amend the Agreement, as set forth
herein.

     NOW, THEREFORE, in consideration of the mutual covenants and agreements
contained in this Amendment, and intending to be legally bound, the parties
agree as follows:

     1.  Amendment of Section 1.82.  Section 1.82 of the Agreement is amended by
         -------------------------
adding the words "with respect to Net Sales achieved in the Territory" after the
words "under the SaSy Agreement" in such Section.

     2.  Amendment of Section 9.1.  Section 9.1 of the Agreement is amended as
         ------------------------
follows:

         a.   Section 9.1 is amended by adding the words "(except as set forth
in the immediately following sentence)" immediately after the words "non-
sublicensable right".

         b.   Section 9.1 is further amended by adding the following after the
     end of Section 9.1:  "ViroPharma may sublicense its activities under this
     Article 9 to an Affiliate of ViroPharma.  Notwithstanding the foregoing,
     ViroPharma shall be solely responsible for activities performed by such
     Affiliate, and the selection and use of an Affiliate shall not relieve
     ViroPharma of its obligations hereunder. For the sake of clarity,
     ViroPharma shall not  be entitled  to sublicense its activities under this
     Article 9 to Third Parties."

     3.  Amendment of Section 14.2.14.  Section 14.2.14 of the Agreement is
         ----------------------------
amended by deleting therefrom "ninety (90)" and replacing it with "one hundred
eighty (180)".

     4.  Amendment of Section 14.3.9.  Section 14.3.9 of the Agreement is
         ---------------------------
amended by deleting therefrom "ninety (90)" and replacing it with "one hundred
eighty" (180)".

     5.  Miscellaneous.
         -------------

         a.   The Agreement shall remain in full force and effect, subject only
to the express changes set forth in this Amendment.
<PAGE>

          b.   The Agreement, as supplemented and modified by this Amendment,
constitutes the entire understanding among the parties with respect to the
subject matter thereof, and supersedes any prior understanding and/or written or
oral agreements among them. All references to "this Agreement" in the Agreement
shall mean the Agreement as modified hereby and from time to time hereafter.

          c.   This Amendment may be executed in counterparts, each of which
shall be an original, but all of which together shall constitute one instrument.
This Amendment will be governed as to validity, interpretation and effect
according to the provisions of Section 17.6 of the Agreement.

     IN WITNESS WHEREOF, the parties have executed this Amendment as of this day
and year first-above written.

AVENTIS PHARMACEUTICALS INC.                 VIROPHARMA INCORPORATED

By: /s/ Jerry Belle                          By: /s/  Michel de Rosen
   --------------------------------------        -------------------------------
   Jerry Belle                                   Michel de Rosen
   President and Chief Executive Officer         President and Chief Executive
                                                 Officer

                                       2<PAGE>

                                                                   EXHIBIT 10.13

                            LNR PROPERTY CORPORATION

                    2001 SENIOR OFFICERS STOCK PURCHASE PLAN
<PAGE>

                               TABLE OF CONTENTS

                                                                            Page
                                                                            ----
1.  Definitions...........................................................    3

2.  Purpose of the Plan...................................................    3

3.  Authority to Enter into Stock Purchase Agreements.....................    3

4.  Terms of Stock Purchase Agreements....................................    4

5.  Withholding Payments..................................................    5

6.  Decision to Enter into Stock Purchase Agreement.......................    6

7.  Administration of the Plan............................................    6

8.  Shares Available for Stock Purchase Agreements........................    6

9.  Modification of Number and Type of Shares.............................    7

10. No Rights to Continued Employment....................................     7

11. No Shareholder Rights................................................     7

12. Effective Date.......................................................     7

13. Governing Law........................................................     7

14. Amendments of the Plan...............................................     7

15. Termination of the Plan..............................................     7

                                      -2-
<PAGE>

                            LNR PROPERTY CORPORATION

                    2001 SENIOR OFFICERS STOCK PURCHASE PLAN

1.   Definitions

     As used in this Plan the following definitions apply:

     (a)  "Board of Directors" means LNR's Board of Directors.

     (b) "Committee" means the Board of Directors, or a committee designated by
the Board of Directors to administer the Plan which consists solely of two or
more "non-employee directors," as that term is defined in Rule 16b-3 under the
Securities Exchange Act of 1934, as amended.

     (c)  "Common Stock" means common stock, par value $.10 per share, of LNR.

     (d)  "Company" means LNR and all its more than 50% owned subsidiaries.

     (e) "Deferred Bonus Payment" means an installment of a bonus which is not
to be paid until more than 10 months after the bonus is awarded. A bonus will be
treated as being awarded to a Senior Officer when LNR informs the Senior Officer
of the amount of the bonus (even if the bonus is awarded under a plan or
agreement which became effective before then).

     (f)  "LNR" means LNR Property Corporation, a Delaware corporation, or its
successor by merger or any similar transaction.

     (g)  "Plan" means this LNR Property Corporation 2001 Senior Officers Stock
Purchase Plan.

     (h) "Purchase Date" means a day on which the Senior Officer who is a party
to a Stock Purchase Agreement is entitled to receive a Deferred Bonus Payment
under a bonus award made at or before the time the Stock Purchase Agreement is
authorized.

     (i) "Senior Officer" means the chairman of the board, the president or a
vice president of LNR or a more than 50% owned subsidiary.

     (j) "Stock Purchase Agreement" means an agreement between a Senior Officer
and LNR, containing the terms described in Paragraph 4, in which the Senior
Officer agrees to purchase shares of Common Stock and LNR agrees to sell those
shares of Common Stock to the Senior Officer.

2.   Purpose of the Plan

     The purpose of the Plan is to encourage Senior Officers to commit to invest
Deferred Bonus Payments to which they will be entitled in Common Stock, and by
doing so to stimulate the efforts of those Senior Officers on behalf of the
Company and strengthen their desire to remain employees of the Company.

3.   Authority to Enter into Stock Purchase Agreements

     The Committee may at any time within 30 days after a bonus is awarded to a
Senior Officer, authorize LNR to enter into a Stock Purchase Agreement with that
Senior Officer relating to purchases on the days on which deferred portions of
that bonus are to be paid of shares of Common Stock with a total purchase price
on each Purchase Date equal to a

                                      -3-
<PAGE>

specified percentage of the Deferred Bonus Payment which is to be made on that
Purchase Date. In addition, the Committee may, not later than April 29, 2001,
authorize LNR to enter into Stock Purchase Agreements with Senior Officers who
were awarded bonuses prior to November 30, 2000 relating to purchases on the
days on which the remaining deferred portions of those bonuses are to be paid of
shares of Common Stock with a total purchase price on each Purchase Date equal
to the specified percentage of the Deferred Bonus Payment which is to be made on
that Purchase Date.

4.   Terms of Stock Purchase Agreements

     Each Stock Purchase Agreement will have the following terms:

     (a) On each Purchase Date on which the Senior Officer who is a party to the
Stock Purchase Agreement is employed by the Company, the Senior Officer will be
required to purchase, for the Share Purchase Price determined as described in
subparagraph (b), a number of shares of Common Stock equal to (i) the specified
percentage of the Deferred Bonus Payment to which the Senior Officer becomes
entitled on that Purchase Date, as specified on a schedule attached to the Stock
Purchase Agreement (which percentage will be deemed to be the same as to each
Purchase Date unless otherwise specified in the schedule attached to the Stock
Purchase Agreement), divided by (ii) the Share Purchase Price determined as
described in subparagraph (b), and LNR will be required to sell that number of
shares to the Senior Officer for that Share Purchase Price.

     (b) The Share Purchase Price under a Stock Purchase Agreement will be the
last sale price of a share of Common Stock reported on the New York Stock
Exchange composite tape (or, if the Common Stock is not listed on the New York
Stock Exchange, reported in the principal market in which the Common Stock is
listed) on the trading day before the day on which the Officer signs the Stock
Purchase Agreement.

     (c) If (i) LNR is involved in a merger, consolidation, dissolution,
liquidation, reorganization, exchange of shares, sale of all or substantially
all of its assets (directly or through sales of subsidiaries or assets of
subsidiaries) or similar transaction, (ii) there is a stock dividend, stock
split, reverse stock split, stock combination, reclassification,
recapitalization or similar change in the capital structure of LNR, or a
distribution to holders of Common Stock other than a cash dividend or (iii) any
other event occurs which in the judgment of the Committee requires an adjustment
to the terms of the existing Stock Purchase Agreements, the Committee may modify
the number of shares of Common Stock to be purchased on each Purchase Date after
the corporate event occurs and the Share Purchase Price in a manner which, in
its judgment, will cause the rights of the parties to the Stock Purchase
Agreement in aggregate to be substantially the same after the corporate event as
they were before the corporate event; provided however, that if as a result of
the corporate event the Senior Officer would be required to purchase anything
other than LNR Common Stock, then within 10 days following such corporate event,
the Senior Officer shall be entitled to terminate the Stock Purchase Agreement
with respect to those Purchase Dates.

     (d) LNR's obligation to issue shares of Common Stock or other securities on
a Purchase Date will be subject to the condition that (i) LNR's counsel is
satisfied that the sale will be in compliance with the Securities Act of 1933,
as amended, and all other applicable laws and (ii) the shares of Common Stock to
be issued under the Stock Purchase Agreement will have been authorized for
listing on all securities exchanges on which the Common Stock is listed. LNR
will do all things in its power so that (x) all sales under all Stock Purchase
Agreements can be made on the Purchase Dates specified in the Stock Purchase
Agreements without violating

                                      -4-
<PAGE>

the Securities Act of 1933, as amended, or any other applicable laws, and (y)
the shares to be issued under all Stock Purchase Agreements will as promptly as
practicable be authorized for listing on each exchange on which the Common Stock
is listed.

     (e) No rights under a Stock Purchase Agreement may be assigned, except that
the Senior Officer who is a party to a Stock Purchase Agreement may assign the
right to purchase Common Stock under that Stock Purchase Agreement to members of
his or her immediate family, to a trust all the beneficiaries of which are the
Senior Officer or members of his or her immediate family, or to an entity which
is wholly owned by the Senior Officer or members of his or her immediate family.
A Senior Officer's assignment of the right to purchase Common Stock under a
Stock Purchase Agreement will not relieve the Senior Officer of liability if
shares which are the subject of the Stock Purchase Agreement are not purchased,
or the purchase price for those shares is not paid, on each Purchase Date as
required by the Stock Purchase Agreement.

     (f) The purchase price of the shares to be purchased on a Purchase Date
will be payable in cash or by check payable to the order of LNR, except that the
Committee may permit a Senior Officer to pay all or part of the purchase price
by directing LNR to retain from the Common Stock to be issued on the Purchase
Date shares with a fair market value (based upon the last reported sale price of
the Common Stock on the last trading day before the Purchase Date) equal to the
purchase price.

     (g) The Stock Purchase Agreement will terminate, and neither the Senior
Officer nor LNR will have any further rights or obligations under the Stock
Purchase Agreement, when the Senior Officer ceases to be an employee of the
Company, except that if the Senior Officer dies while he or she is an employee
of the Company, the executor or other fiduciary who administers the Senior
Officer's estate may, by a notice given to the Company within 90 days after the
day of the Senior Officer's death (accompanied by payment of the purchase price
of any shares which were to have been purchased between the day of the Senior
Officer's death and the day on which the notice is given) continue the Stock
Purchase Agreement in effect for the benefit of the persons who are entitled
under the Senior Officer's will or the laws of descent and distribution to
receive the Deferred Bonus Payments which are payable on the same days as the
Purchase Dates under the Stock Purchase Agreement. Termination of the Stock
Purchase Agreement will not, however, relieve either the Senior Officer or LNR
from any liability because of a breach of the Stock Purchase Agreement which
occurs before it terminates.

5.   Withholding Payments

     If as a result of a Senior Officer's purchase of Common Stock under a Stock
Purchase Agreement on a Purchase Date, the Company is required to pay an amount
as withheld income tax, LNR may, at its discretion, (i) reduce the number of
shares of Common Stock issuable upon payment of the purchase price on that
Purchase Date by the amount of the required withholding (with the shares valued
at their fair market value, based upon the last reported sale price of the
Common Stock, on the last trading day before the Purchase Date), (ii) require
that, before LNR will deliver to the Senior Officer the certificates
representing the purchased shares, the Senior Officer must remit to LNR the
amount of withholding tax the Company is required to pay or (iii) withhold the
amount of the withholding tax from the Deferred Bonus Payment the Senior Officer
is entitled to receive on that Purchase Date.

                                      -5-
<PAGE>

6.   Decision to Enter into Stock Purchase Agreement

     Promptly after LNR is authorized to enter into a Stock Purchase Agreement
with a Senior Officer, LNR will ask the Senior Officer whether he or she wants
to enter into a Stock Purchase Agreement and if so, the percentage or
percentages of the applicable Deferred Bonus Payments which the Senior Officer
wants to invest through the Stock Purchase Agreement in purchasing Common Stock
under this Plan.  If the Senior Officer responds within 30 days that the Senior
Officer wants to enter into a Stock Purchase Agreement and specifies the
percentage or percentages of the Deferred Bonus Payments which the Senior
Officer wants to invest in purchasing Common Stock, LNR will promptly deliver
copies of the Stock Purchase Agreement to the Senior Officer for signature.  If
a Senior Officer does not respond within 30 days to an inquiry by LNR as to
whether the Senior Officer wants to invest a portion of his or her Deferred
Bonus Payments in purchasing Common Stock under this Plan, or the Senior Officer
does not return a signed copy of a Stock Purchase Agreement within 30 days after
it is delivered to him or her for signature, the Senior Officer will be deemed
irrevocably to have elected not to invest any portion of the Deferred Bonus
Payments in purchasing Common Stock under this Plan.

7.   Administration of the Plan

     (a) The Plan will be administered by the Committee.

     (b) The Committee will have full power to construe, interpret and
administer the Plan and to establish and change the rules and regulations for
its administration.

     (c) Subject to the limitations contained in the Plan, the Committee will
have full power to authorize LNR to enter into Stock Purchase Agreements with
particular Senior Officers and to determine the Share Purchase Price under each
Stock Purchase Agreement, calculated as described in Paragraph 4(b).

     (d) In exercising its powers under the Plan, the Committee may act in its
sole discretion, with no requirement that it follow past practices or treat one
Senior Officer in a manner consistent with the way it treats other Senior
Officers.

     (e) All actions taken and decisions made by the Committee will be binding
on all parties to Stock Purchase Agreements which are affected by the actions or
decisions, and on their respective legal representatives and beneficiaries.

     (f) No member of the Committee will be liable for any determination made or
action taken in good faith with respect to the Plan or any Stock Purchase
Agreement entered into in accordance with the Plan, or for any decision not to
authorize LNR to enter into Stock Purchase Agreements with particular Senior
Officers.

8.   Shares Available for Stock Purchase Agreements

     The aggregate number of shares of Common Stock which may be made the
subject of Stock Purchase Agreements under this Plan is 500,000 shares, subject
to adjustment as provided in Section 9.  Those shares will not affect the number
of shares available under any other LNR plan.  Any shares which are subject to
Stock Purchase Agreements which terminate because the Senior Officers who are
parties to the Stock Purchase Agreements cease to be employees of the Company
will be available to be made the subject of other Stock Purchase Agreements.
Any shares which are purchased under Stock Purchase Agreements, but which LNR
retains to pay the purchase price of shares or to reimburse the Company for
paying withholding taxes will be deemed to have been issued under those Stock
Purchase Agreements and will not be available to be made the subject of other
Stock Purchase Agreements.

                                      -6-
<PAGE>

9.   Modification of Number and Type of Shares for Future Stock Purchase
Agreements

     If at any time (i) there is a stock dividend, stock split, reverse stock
split, stock combination, reclassification, recapitalization or similar change
in LNR's capital structure or (ii) any other event occurs which in the judgment
of the Committee requires an adjustment to the number and type of shares
available to be made the subject of Stock Purchase Agreements entered into in
the future, the Committee may modify the number and type of shares available to
be made the subject of future Stock Purchase Agreements in a manner which, in
its judgment, will cause the portion of LNR's common shares available to be made
the subject of future Stock Purchase Agreements in aggregate to be substantially
the same after the corporate event as they were before the corporate event.

10.  No Rights to Continued Employment

     Nothing in the Plan or in any Stock Purchase Agreement, and no action taken
by the Committee, will give any Senior Officer a right to continue to be an
officer or employee of the Company or in any other way affect the right of the
Company to terminate the employment or the position of any Senior Officer at any
time for any reason, with or without cause.

11.  No Shareholder Rights

     A Senior Officer will not have any rights as a shareholder with regard to
shares of Common Stock that are the subject of a Stock Purchase Agreement until
shares are purchased and paid for.

12.  Effective Date

     The Plan will be effective on the day when it is adopted by the Board of
Directors.

13.  Governing Law

     This Plan and each Stock Purchase Agreement issued under it will be
governed by the substantive laws of the State of Delaware.

14.  Amendments of the Plan

     The Board of Directors may amend the Plan at any time.  However, no
amendment to the Plan will change any Stock Purchase Agreement which is signed
before the amendment is effective, unless the Senior Officer who is a party to
the Stock Purchase Agreement consents to the amendment.

15.  Termination of the Plan

     The Plan may be terminated at any time by the Board of Directors. However,
termination of the Plan will not affect any Stock Purchase Agreement that is
executed before the Plan is terminated.

                                    *  *  *

       As approved by the Board of Directors of LNR Property Corporation
                              on January 17, 2001

                                      -7-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00034-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00034-of-00352.parquet"}]]