Document:

<PAGE>

                                                                 EXHIBIT 10.29

     Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.

                                                                      SCHERING

-------------------------------------------------------------------------------

Millennium & ILEX Partners, L.P.                        Schering AG
c/o ILEX Oncology, Inc.                                 Legal Department
4545 Horizon Hill Boulevard
San Antonio, TX 78229

Millennium & ILEX Partners, L.P.
c/o Millennium Pharmaceuticals, Inc.
75 Sidney Street
Cambridge, MA 02139

Your Ref.                      Your letter dated

Our Ref. (please indicate when replying) Telephone +49-30-468-14707  Date
                                                    49-30-468-11 11
Dr. Murati-Laebe/ch (ob 1912-1)          Telefax   +49-468-14088     2000-12-19

Re:      AMENDMENT NO. 1 TO CAMPATH DISTRIBUTION AND DEVELOPMENT AGREEMENT

Ladies and Gentlemen:

Reference is hereby made to that certain Distribution and Development Agreement
dated as of August 23, 1999 (the "AGREEMENT") by and between Millennium & ILEX
Partners, L.P., formerly known as L&I Partners, L.P. ("M&I") and Schering AG
(the "DISTRIBUTOR"). The PARTIES desire to set forth their agreement to certain
amendments to the AGREEMENT in accordance with the terms and conditions herein
set forth.

"REIMBURSABLE MARKETING EXPENSES" shall mean the MARKETING EXPENSES incurred in
the PROFIT-SHARING TERRITORY with respect to PRODUCT for an INDICATION prior to
launch thereof incurred by the AFFILIATE of DISTRIBUTOR that is distributing
PRODUCT in the PROFIT-SHARING TERRITORY. The REIMBURSABLE MARKETING EXPENSES for
the CLL

<PAGE>

ILEX Partners, L.P.           Dr. Murati-                    2000-12-19       2
                              Laebe/ch(Ob1912-1)

     Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.

1. Section 1.51 of the AGREEMENT shall be amended and restated in its entirety
as follows:

INDICATION shall in the aggregate not exceed [**] Dollars ($[**]). The PARTIES
agree that [**]% of the maximum $[**] of REIMBURSABLE MARKETING EXPENSES for the
CLL INDICATION incurred by BERLEX for the CLL INDICATION in the PROFIT SHARING
TERRITORY shall be reimbursed to DISTRIBUTOR by M&I. The PARTIES further agree
that the amount of such reimbursement shall not exceed $[**]. For OTHER
INDICATIONS, the maximum amount of REIMBURSABLE MARKETING EXPENSES shall be
determined by the MARKETING COMMITTEE. With respect to aggregate REIMBURSABLE
MARKETING EXPENSES incurred by BERLEX for the CLL INDICATION in excess of $[**]
but less than $[**], such reimbursement shall occur within 30 days after receipt
by M&I of an invoice from DISTRIBUTOR, which invoice (i) shall be issued after
the end of each CALENDAR QUARTER commencing with the CALENDAR QUARTER ended
September 30, 2000; and (ii) shall include the full details of such actual
expenses and the assumptions upon which the invoiced amount is based, all in
accordance with the terms of this AGREEMENT and GAAP. With respect to the first
$[**] of such aggregate REIMBURSABLE MARKETING EXPENSES, one eighth (1/8) shall
be charged against EARNINGS for the PRODUCT for the CLL INDICATION in each of
the eight CALENDAR QUARTERS after launch thereof."

2. Section 1.52 of the AGREEMENT is amended by inserting the following at the
end of such Section:

"The PARTIES agree that (a) [**] of SELLING EXPENSES incurred by BERLEX during
the YEAR 2000 prior to the launch of PRODUCT for the CLL INDICATION in the
PROFIT SHARING TERRITORY shall be reimbursed to DISTRIBUTOR by M&I; and (b)
solely for the YEAR 2000, such SELLING EXPENSES shall be increased by no more
than $[**] to include certain one-time expenses for certain sales force training
activities incurred by BERLEX prior to the launch of the PRODUCT for the CLL
INDICATION. The PARTIES further agree that the amount of such reimbursement
shall not exceed $[**]. Such reimbursement shall occur within 30 days after
receipt by M&I of an invoice from DISTRIBUTOR, which invoice (i) shall be issued
after the end of each CALENDAR QUARTER commencing with the CALENDAR QUARTER
ended September 30, 2000; and (ii) shall include the full details of such actual
expenses and the assumptions upon which the invoiced amount is based, all in
accordance with the terms of this AGREEMENT and GAAP."

3.       Section 3.4 of the AGREEMENT is amended by inserting the following new
         subparagraph (c) at the end thereof:

"(c) Notwithstanding the foregoing provisions of this Section 3.4, neither M&I
nor DISTRIBUTOR shall be obligated to pay or be charged those amounts of SELLING
EXPENSES and REIMBURSABLE MARKETING EXPENSES that have been invoiced to, and
previously paid by, M&I or DISTRIBUTOR, as the case may be, under Sections

<PAGE>

ILEX Partners, L.P.           Dr. Murati-                    2000-12-19       3
                              Laebe/ch(Ob1912-1)

1.51 or 1.52 of this AGREEMENT. For the purpose of calculating the QUARTERLY
Payment of APPROPRIATE PERCENTAGE of EARNINGS to avoid duplicate payment or
charge, those amounts of SELLING EXPENSES and REIMBURSABLE MARKETING EXPENSES
that have been invoiced to, and previously paid by, M&I or DISTRIBUTOR, as the
case may be, under Sections 1.51 or 1.52 of this AGREEMENT shall be excluded
from EARNINGS."

4. Section 3.5 of the AGREEMENT is amended and restated in its entirety as
follows:

"3.5 YEARLY Payment of APPROPRIATE PERCENTAGE

With respect to the PROFIT-SHARING TERRITORY, within sixty (60) days of the end
of each YEAR, DISTRIBUTOR shall separately determine EARNINGS for PRODUCT for
the YEAR for the CLL INDICATION and, subject to Section 3.7, for each OTHER
INDICATION as to which DISTRIBUTOR retains distribution rights and M&I shall
receive or pay the APPROPRIATE PERCENTAGE of the EARNINGS (excluding from the
calculation of EARNINGS, to avoid duplicate payment or charge, those amounts of
SELLING EXPENSES and REIMBURSABLE MARKETING EXPENSES that have been invoiced to,
and previously paid by, M&I or DISTRIBUTOR, as the case may be, under Sections
1.51 or 1.52 of this AGREEMENT) therefor for the applicable YEAR, adjusted for
the aggregate of the amounts received and/or paid by M&I under Section 3.4 for
the CALENDAR QUARTERS of the appropriate YEAR. Any payment due from DISTRIBUTOR
shall be made within ninety (90) days of the end of the applicable YEAR, or
thirty (30) days after delivery of the report of EARNINGS for such YEAR,
whichever is earlier. Any payment due to DISTRIBUTOR shall be made within thirty
(30) days after M&I receives the yearly report under Section 3.3."

5. The AGREEMENT is further amended as follows:

         a.   All references in the AGREEMENT to "L&I Partners, L.P." shall be
              changed to "Millennium & ILEX Partners, L.P.";

         b.   All references in the AGREEMENT to "L&I" shall be changed to
              "M&I"; and

         c.   All references in the AGREEMENT to "LEUKOSITE" shall be changed to
              "MILLENNIUM"; and Section 1.31 shall be amended in its entirety to
              read as follows:

              "1.31  "MILLENNIUM" means Millennium Pharmaceuticals, Inc., a
              Delaware corporation."

         d.   Section 23.1 of the AGREEMENT shall be amended to provide that
              notices to M&I shall be delivered to the following addresses:

<PAGE>

ILEX Partners, L.P.           Dr. Murati-                    2000-12-19       4
                              Laebe/ch(Ob1912-1)

                  To M&I:

                  Millennium & ILEX Partners, L.P.
                  c/o ILEX Products, Inc.
                  4545 Horizon Hill Boulevard
                  San Antonio, TX 78229

                  and

                  Millennium & ILEX Partners, L.P.
                  c/o Millennium Pharmaceuticals, Inc.
                  75 Sidney Street
                  Cambridge, MA 02139
                  Attn: Chief Executive Officer

                  Copy to:

                  Millennium Pharmaceuticals, Inc.
                  75 Sidney Street
                  Cambridge, MA 02139
                  Attn: Legal Department

This Amendment No. 1 sets forth the entire agreement of the PARTIES as to the
amendment of the AGREEMENT and supercedes all prior discussions, arrangements
and understandings with respect to any such amendment. This Amendment No. 1
shall be effective as of the date first written above. From and after the date
first written above, all references in and to the AGREEMENT shall be deemed to
include this Amendment No. 1. This Amendment No. 1 is limited as specified, and
shall not constitute an amendment, modification, or waiver of any other
provision of the AGREEMENT. This Amendment No. 1 shall be subject to Section
19.1 of the AGREEMENT. This Amendment No. 1 may be executed in two or more
counterparts, each of which shall be deemed to be an original, but all of which
taken together shall constitute one and the same instrument.

<PAGE>

ILEX Partners, L.P.           Dr. Murati-                    2000-12-19       5
                              Laebe/ch(Ob1912-1)

Please signify the agreement of M&I to this Amendment No. 1 by signing the
enclosed copy of this letter and returning the same to the first undersigned.

Very truly yours,

SCHERING AKTIENGESELLSCHAFT

By: [illegible]
   ---------------------------
    Name:
    Title:

By: /s/Klaus Nickison
   ---------------------------
    Name:  Klaus Nickison
    Title: Portfolio Manager

Acknowledged and agreed:

MILLENNIUM & ILEX PARTNERS, L.P.

By MILLENNIUM & ILEX, L.L.C., its General Partner

By: /s/Steven H. Holtzman
   ---------------------------
    Name:  Steven H. Holtzman
    Title: President

By: /s/Ze'ev Shaked
   ---------------------------
    Name:  Ze'ev Shaked
    Title: Vice President & Manager<PAGE>

                                                                   EXHIBIT 10.40

         Each of the following executive officers of the Company have made
promissory notes in favor of the Company (as successor to the Company's former
subsidiaries) on substantially the terms set forth in the promissory note
attached hereto on the dates, for the principal amounts and at the interest
rates set forth below:

<TABLE>
<CAPTION>
NAME OF EXECUTIVE        DATE OF EXECUTION          AGGREGATE
OFFICER                                             PRINCIPAL AMOUNTS     INTEREST RATE
<S>                      <C>                        <C>                   <C>
Steven H. Holtzman       May 1998                   $31,690               5.73%
                         July 1998 and 1999

Mark J. Levin            May 1998 and January 1999  $23,699               5.69%

John Maraganore          May 1998                   $269,398.82           5.60%
</TABLE>

<PAGE>

                  SECURED PROMISSORY NOTE AND PLEDGE AGREEMENT

$[Principal Amount]                                     [Date]
                                                        Cambridge, Massachusetts

         FOR VALUE RECEIVED, the undersigned [Name], promises to pay to [Name of
Subsidiary], a Delaware corporation (the "Company"), the principal sum of
$[Principal Amount], together with interest, compounded on each anniversary of
the date hereof, at the rate of [insert the IRS applicable federal interest rate
for mid-term instruments for month in which Note is issued] per year until paid
in full. All principal and interest will be due and payable on earlier to occur
of:

                  (i)      ________ __, 200__ [5 years from the date of issuance
                  of the Stock Option Agreement]; and

                  (ii) the date on which the undersigned ceases (regardless of
                  the reason therefor) to be employed by (a) the Company, (b)
                  its parent, Millennium Pharmaceuticals, Inc., a Delaware
                  corporation (the "Parent"), or (c) any present or future
                  subsidiary corporation of the Parent or the Company.

From and after the occurrence of a default hereunder, this Note shall bear
interest at the rate of [insert applicable interest rate plus 2 percentage
points] until paid in full.

         SECURITY INTEREST. The undersigned, as security for payment of this
Note and the Damage Amount set forth in Section 3(d) of that certain Stock
Restriction Agreement of even date between the Company and the undersigned (the
"Restriction Agreement"), hereby grants a first priority security interest in
and assigns and pledges to the Company, together with any and all dividends,
distributions or other proceeds thereof, ___ shares of Common Stock of the
Company (represented by certificate no. __) (the "Shares"). The undersigned
agrees to cause all non-cash dividends and distributions with respect to the
Shares to be distributed directly to the Company, to be held by the Company as
part of the Shares. The undersigned acknowledges and understands that the
Company's only duty with respect to the Shares is to exercise reasonable care to
secure the safe custody of the Shares.

         DEFAULT. This Note will become immediately due and payable, without any
prior notice or demand to the undersigned by the Company, upon the occurrence at
any time of any of the following: (a) the undersigned's failure to pay when due
any principal or interest under this Note; (b) if bankruptcy, reorganization,
receivership or insolvency proceedings are instituted by or against the
undersigned; (c) the death or incapacity of the undersigned; or (d) any
representation or warranty set forth herein or in the Restriction Agreement is
no longer true or correct. If any of the events listed in items (a) through (d)
above occur, the Company may, in its sole discretion, resort to any and all
remedies available to a secured party under the Uniform Commercial Code as
enacted and in effect from time to time, in the Commonwealth of Massachusetts or
under applicable law (which shall include the sale of the Shares). Furthermore,
the Company may sell all or

<PAGE>

any part of the Shares at a public or private sale, exercise all rights with
respect to the Shares as if the Company were the absolute owner (including the
right to vote the Shares), or take title to the Shares. The exercise by the
Company of any one or more remedies shall not preclude the Company from
exercising any other remedies it may have, it being acknowledged that all such
rights and remedies are cumulative. The undersigned acknowledges that the
Company may be unable to effect a public sale of all or part of the Shares by
reason of certain prohibitions contained in the Securities Act of 1933, as
amended, and may be compelled to resort to one or more private sales to a
restricted group of purchasers at prices and on terms less favorable to the
seller than if sold at public sales and that private sales shall be deemed to be
made in a commercially reasonable manner notwithstanding that such a private
sale may result in a lower sale price. In the event the Company sells the
Shares, the proceeds will first be applied to the payment of any expenses of the
sale, including brokerage commissions, counsel fees, taxes and any other charges
or expenses incurred by the Company pertaining to the sale; and, second, to
satisfy any unpaid amounts due under this Note; and, third, the surplus (if any)
will be paid to the undersigned.

         INDEMNIFICATION; COSTS AND EXPENSES. The undersigned agrees to
compensate the Company and hold it harmless from and against any loss,
liability, damage, expense, cost and reasonable attorney fees incurred by the
Company in exercising its rights or remedies under this Note or defending or
protecting the security interest created hereunder. Any such compensation will
be paid by the undersigned upon demand by the Company, become part of the
obligation secured by the Shares and bear interest at the rate provided in this
Note.

         ESCROW. The undersigned irrevocably directs the Company, upon payment
in full of this Note, to deliver to such person who has been named by the
Company to act as escrow agent pursuant to the Joint Escrow Instructions
attached as EXHIBIT B to the certain Stock Restriction Agreement dated ________
__, ____ [insert date of Stock Restriction Agreement] by and between the
undersigned and the Company, the attached Assignment Separate from Certificate
and the certificate(s) evidencing the Shares, to be held by such escrow agent
pursuant to the terms of such Joint Escrow Instructions. The undersigned
acknowledges and agrees that prior to payment in full of this Note, the Shares
are being held by the Company solely as a secured party and pledgee thereof and
not for the benefit of the undersigned or as escrow agent pursuant to the Joint
Escrow Instructions.

         NOTICES. All notices hereunder to the undersigned or the Company will
be sent by United States first class or certified or registered mail, postage
prepaid, or by telecopy or by hand; if to the Company at 238 Main Street,
Cambridge, Massachusetts 02142; and to the undersigned at such address as has
been furnished to the Company from time to time.

         MISCELLANEOUS. The security interest in the Shares and the other
provisions of this Note that are related to the security interest in the Shares
will be binding upon any heirs, executors, administrators or other transferees
of the undersigned. None of the terms or provisions of this Note may be
excluded, modified or amended except in writing signed

<PAGE>

by the undersigned and the Company. All rights and obligations hereunder shall
be governed by the laws of the Commonwealth of Massachusetts (except for its
conflict of laws) and this Note is executed as an instrument under seal.

WITNESS:                                         BORROWER:

By:_____________________________         ________________________________
     Signature                                   Signature

     Address:________________________

_____________________________

Agreed and acknowledged as of the date
first written above.

[Name of Subsidiary]

By:___________________________________________
     Title:

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00021-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00021-of-00352.parquet"}]]