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                                                                    EXHIBIT 10.5

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


                                                                               1


                    CHEMILOG DEVELOPMENT AND SUPPLY AGREEMENT




BETWEEN   UCB-BIOPRODUCTS S.A., with registered office at Allee de la Recherche
          60, B-1070 Brussels, Belgium ("UCB")


                                                                on the one hand,


AND       THE MEDICINES COMPANY INC., a Delaware corporation with offices at One
          Cambridge Center, Suite 408, Cambridge, Massachusetts 02142, USA,
          ("TMC")


                                                              on the other hand,


WHEREAS, TMC has acquired certain rights to the synthetic drug substance
Bivalirudin (Angiomax(R)) and is interested in developing and marketing
pharmaceutical compositions containing Bivalirudin for the treatment of PTCA and
other diseases; and


WHEREAS, UCB has suitable premises, equipment and expertise in the development
and production of pharmaceutical grade bulk peptides; and


WHEREAS, with a view to entering into a supply commitment TMC wishes UCB to
develop a new manufacturing process (the CHEMILOG PROCESS) of the active
pharmaceutical ingredient Bivalirudin, on the terms and conditions of this
Agreement;


IN CONSIDERATION OF THE MUTUAL COVENANTS CONTAINED HEREIN, TMC AND UCB (THE
"PARTIES") AGREE AS FOLLOWS:


ARTICLE 1 - DEFINITIONS

When used herein, the following terms, used with initial capital letters, shall
have the following respective meanings and the singular shall include the plural
and vice-versa:

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                                                                               2


1.1      "AFFILIATE" shall mean with respect to a party (i) any company at least
         fifty percent (50%) of whose issued and voting capital is owned or
         controlled, directly or indirectly, by said party, or (ii) any company
         which owns or controls, directly or indirectly, at least fifty percent
         (50%) of the issued and voting capital of said party, or (iii) any
         company owned or controlled, directly or indirectly, to the extent of
         at least fifty percent (50%) of the issued and voting capital, by any
         of the foregoing.


1.2      "API" shall mean Active Pharmaceutical Ingredient.


1.3      "BIVALIRUDIN" shall mean the 20 amino acid polypeptide corresponding
         to UCB Code Name SF071 and/or SF220.


1.4      "CHEMILOG" shall mean the process by which Bivalirudin API is
         manufactured in accordance with the process as described in ANNEX 1
         hereto.


1.5      "CONFIDENTIAL INFORMATION" shall mean any UCB or TMC trade secret or
         other information of a confidential and/or proprietary nature which is
         disclosed by one party ("DISCLOSING PARTY") to the other party
         ("RECEIVING PARTY") and which is marked as "confidential" or
         "proprietary", excluding such trade secret or other information which
         (i) is published or otherwise becomes a matter of public knowledge by
         any means other than through the breach of this Agreement by the
         Receiving Party, (ii) was known by the Receiving Party at the time of
         such disclosure, as evidenced by the Receiving Party's written records
         predating such disclosure and maintained in the ordinary course of
         business, (iii) was disclosed to the Receiving Party by any Third Party
         (as defined below) who has the right to disclose the same; (iv) was
         independently developed by the Receiving Party, without using the
         Disclosing Party's Confidential Information; or (v) is disclosed
         pursuant to court order or as otherwise required by law, after giving
         the Disclosing Party prior written notice of such required disclosure
         and after assisting the Disclosing Party in its reasonable efforts to
         prevent or limit such disclosure.


1.6      "DRUG PRODUCT" shall mean any pharmaceutical composition containing the
         Bivalirudin API.

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                                                                               3

1.7      "FIRST SALE DATE" shall mean the first date on which TMC sells Drug
         Product to a Third Party which contains Product supplied by UCB
         hereunder and manufactured through the Chemilog Process.

1.8      "PRODUCT" shall mean the fully chemically synthetized Bivalirudin API
         either through UCB's existing process or the Chemilog Process.

1.9      "SPECIFICATIONS" shall mean the characteristics of the Product,
         attached hereto as ANNEX 2 to this Agreement.

1.10     "THIRD PARTY" shall mean any natural person, corporation, firm, trust,
         joint venture, company, partnership or other business organization,
         which is not a party hereto or an Affiliate of any party hereto.

1.11     "UCB TECHNICAL INFORMATION" shall mean:

         a) unpatented proprietary and confidential technical information,
         specifications, compositions, manufacturing methods, application
         methods, testing methods, computer programs, technical data and
         drawing as well as any improvements thereto, whether written or oral,
         which relates to the Chemilog Process or to the Product manufactured
         through other processes, and which is useful or necessary for the
         implementation of this Agreement, as shall have been developed or
         acquired by UCB prior to the termination or expiration of this
         Agreement (excluding information supplied by TMC);

         b) patents and patent applications on any of the foregoing, including
         divisions, continuations, continuations in part, extensions,
         amendments and reissues thereof, filed or owned by, or licensed or
         assigned to UCB, and based on inventions which are either (i) actually
         reduced to practice or (ii) constructively reduced to practice by
         filing a patent application on such invention prior to the termination
         of this Agreement;

         provided that the UCB Technical Information shall not include
         information acquired by UCB from third parties subject to
         confidentiality restrictions preventing disclosure or use hereunder.

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                                                                               4


ARTICLE 2 - SUBJECT-MATTER OF THE AGREEMENT

2.1      In order to establish UCB as a preferred supplier of the Product on a
         commercial basis, UCB shall perform the development and manufacture of
         the Product in its premises in Braine-l'Alleud, Belgium according to
         the terms hereunder. The Product shall not be manufactured at any other
         facilities unless the Parties mutually agree otherwise. This
         development will cover all necessary steps, including development,
         qualification and validation steps, up to and including the filing of a
         Drug Master File with the FDA related to Chemilog as far as it concerns
         the activities performed at and by UCB. UCB shall also file or provide
         TMC the equivalent documentation of the local equivalent of a Drug
         Master File in any countries TMC or its Affiliates chooses to register
         the Product. However, UCB shall not be obliged to file in any country
         in which UCB has no previous experience of filing the local equivalent
         of a Drug Master File. Alternatively, parties may agree on a specific
         remuneration for UCB for filing in countries in which UCB has no
         previous experience of filing.


2.2      During the term of this Agreement, TMC shall purchase at least eighty
         percent (80%) of its annual requirements of Product from UCB, subject
         to Article 21 below. In the event that TMC instructs UCB to transfer
         UCB Technical Information to a Third Party, in order for such Third
         Party to act as a second supplier of Product for TMC, TMC shall pay to
         UCB both during and after the term of this Agreement (but in no event
         after the date when Product becomes generic in the U.S.A.) an annual
         royalty payment equal to ten percent (10%) of the amount paid by TMC
         for its purchases of the Product manufactured by such Third Party.


ARTICLE 3 - SCOPE OF WORK

The Parties agree that the Scope of Work (hereinafter referred to as "SOW")
attached in Annex 3 constitutes an integral part of the Agreement. UCB shall use
best efforts to follow the SOW in reaching the requested degree of experience
for commercial manufacturing purposes, as well as the associated controls,
related to the Product.


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                                                                               5


ARTICLE 4 - MILESTONES REPORTS.

At each milestone described in the SOW UCB will address a written interim
milestone report to TMC. Upon successful completion of the SOW UCB shall address
a final written report to TMC.


ARTICLE 5 - TIMELINES

The general timelines for the development of the Product as described hereabove
are described in ANNEX 4. UCB shall use its reasonable efforts to comply with
such timelines, taking into account, however, the uncertainty of any
development. Should unexpected results arise during the development, the Parties
shall review the timelines within ten (10) business days, to reflect any
decision taken jointly to best resolve the issues.


ARTICLE 6 - DEVELOPMENT PROGRAM REVIEW.

A steering committee with an equal number of representative(s) of TMC and UCB
will be set up upon signature of this Agreement. It will meet according to a
regular and appropriate schedule (until the Parties agree otherwise, at least on
a quarterly basis), at rotating sites, to review the overall progress of the
development, to resolve any unexpected issues that may arise, including but not
limited to, adapting timelines, reviewing quantities, and setting
Specifications. The steering committee shall also conduct phone updates twice
monthly. The steering committee may also decide (on terms to be agreed) to
provide mutual assistance in respect of the development as provided in Article 2
hereof, such as staff swapping or patent filing.


ARTICLE 7 - PRELIMINARY WORK

UCB has already initiated some preliminary work for the development of the
Product, the results of which are described in ANNEX 5; these results are a part
of this Agreement and are subject to the same terms and conditions.

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          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.
                                                                               6

ARTICLE 8 -  FORECASTS AND ORDERS FOR THE PRODUCT

8.1      TMC shall submit to UCB a bi-annual rolling Product forecast, updated
         at the beginning of each calendar quarter. The first two quarters of
         said forecast shall be binding upon TMC to the extent of one hundred
         percent (100%) of such forecasted volume. The third quarter of said
         forecast shall be binding upon TMC to the extent of fifty percent (50%)
         of the forecasted volumes; PROVIDED, HOWEVER, that for the first
         forecast containing a quarter in which TMC's forecast is greater than
         zero (exceeding purchases of validation batches), the forecast for the
         third quarter shall be binding upon TMC to the extent of one hundred
         percent (100%) of such forecasted volume. Binding forecasts shall be
         considered as firm purchase orders.

         For the purposes of this Agreement, an Annual Production Forecast shall
         mean: (i) the first quarter in which TMC's forecast is greater than
         zero (exceeding purchases of validation batches) and the following
         three quarters; and (ii) each four quarter period thereafter.

8.2      Any and all purchase orders for Product shall be issued at least
         sixty (60) days in advance of the required delivery date.

8.3      UCB agrees to reserve manufacturing capacity in its production
         facilities in Braine-l'Alleud, Belgium, so as to ensure that it is able
         to manufacture TMC 's annual requirements of Product. For that purpose,
         UCB shall provide TMC with a capacity plan based upon TMC's bi-annual
         forecasts for Product. Such capacity plan shall outline UCB's capital
         investments. UCB shall at each moment in time guarantee a capacity
         equal to [  **  ] of TMC's forecast for Product for the next two
         (2) quarters.

         The forecast will commence for the first calendar quarter following
         execution of this Agreement. This forecasting procedure shall not apply
         to TMC's order of Chemilog validation batches.

<PAGE>   7
          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.

                                                                               7

ARTICLE 9 - CONSIDERATIONS FOR THE DEVELOPMENT.

9.1      In consideration of the development of the Product described in Article
         2 hereof (including the preliminary work and the SOW), TMC shall pay to
         UCB an amount of (exclusive of any taxes, other than taxes measure on
         the gross or net income of UCB) in accordance with the payment schedule
         set out in Annex 8 hereto.

9.2      Target price for Product.

         9.2.1
                  Subject to the adjustments described in Section 9.2.2 below,
                  each order of Product purchased by TMC shall be priced as
                  follows, based on the Annual Production Forecast which
                  includes the calendar quarter during which such order was
                  purchased by TMC:

                  Total Volume of Annual Production Forecast    Target Price

                  [ ** ] kg or more, but less than [ ** ]kg     US$ [ ** ]/gram
                  [ ** ] kg or more, but less than [ ** ]kg     US$ [ ** ]/gram
                  [ ** ] kg or more                             US$ [ ** ]/gram



         provided, however, that for any twelve (12) month period covered by an
         Annual Production Forecast of [ ** ] kg or more, if during the
         immediately prior twelve (12) month period TMC purchased [ ** ] kg or
         more of Product, then TMC shall pay a target price for the current
         twelve (12) month period equal to the target price paid for such prior
         twelve (12) month period, after it is adjusted pursuant to Section
         9.2.2. below.

         9.2.2    Within thirty (30) days after the end of the twelve-month
                  period covered by an Annual Production Forecast, the Parties
                  shall meet to determine what adjustments need to be made to
                  the amounts paid by TMC during the just-completed twelve (12)
                  month period, based on the factors and procedures described in
                  Scorecard

<PAGE>   8
          Confidential Materials omitted and filed separately with the
        Securities and Exchange Commission. Asterisks denote omissions.

                                                                               8

                  Procedure, attached as Annex 6 hereto; provided, however,
                  that (i) for those twelve (12) month periods where TMC paid
                  a target price of US$[ ** ]/gram, in no event shall such
                  adjustments result in TMC paying less than US$[ ** ]/gram or
                  more than US$[ ** ]/gram; and (ii) for those twelve (12)
                  month periods where TMC paid a target price of
                  US$[ ** ]/gram, in no event shall such adjustments result in
                  TMC paying less than US$[ ** ]/gram or more than
                  US$[ ** ]/gram.

         9.2.3    If TMC forecasts less than [ ** ] kg for any twelve (12) month
                  period covered by an Annual Production Forecast, the target
                  price described in Section 9.2.1 will not be applicable and
                  TMC and UCB will discuss in good faith the price to be paid by
                  TMC for such period. If TMC forecasts more than [ ** ] kg for
                  any twelve (12) month period covered by an Annual Production
                  Forecast, TMC must purchase at least [ ** ] kg during such
                  twelve (12) month period.

ARTICLE 10 -  PAYMENT TERMS FOR DELIVERIES OF PRODUCT.

Each payment hereunder will be due thirty (30) days from the date of invoice.
The invoices will be issued and dated upon delivery of the Product to TMC. Any
deferred payment will automatically bear an interest rate according to EURIBOR Q
months) plus five percent (5%).

The price shall be adjusted as follows to reflect exchange rate fluctuations. At
any time during the first fifteen (15) days of a calendar quarter, either Party
may request an adjustment to be made. On the date of such request, if the
average of the exchange rate of US$ into Euro (L), as reported in the Wall
Street Journal (Eastern Edition), for the ten (10) business day period
immediately preceding that date, as compared to the rate of exchange between
those currencies as applicable at the day of signature of this Agreement or the
date of the last price adjustment, (i) varies by less than [ ** ],
then there shall be no purchase price adjustment at that time; (ii) varies by
[ ** ] or more (but less than [ ** ]), then the purchase price shall be adjusted
to reflect [ ** ] of such change; and (iii) varies by [ ** ] or more, then the
Parties shall meet to find a solution protecting the interests of both Parties.

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                                                                               9


ARTICLE 11 - SHIPMENT AND PACKAGING.

Each shipment of Product will be made according to the relevant SOP's applicable
at UCB in Braine-l'Alleud (Belgium) and any particular requirement TMC might
have and previously approved by UCB. Delivery shall occur EX WORKS
Braine-l'Alleud (ICC Incoterms 1990).

ARTICLE 12 - SPECIFICATIONS.

12.1     The draft Specifications of the Product are attached hereto as ANNEX 2.
         The final Specifications will be attached hereto as ANNEX 2 upon
         achievement of the development work as set out in the SOW, and such
         final Specifications shall be mutually agreed upon by the Parties. In
         addition, such final Specifications shall be at least as stringent as
         those specifications in place for the Product manufactured by the
         registered process at the time of registration.

12.2     UCB agrees that TMC may change the Specifications only for regulatory
         requirements, provided that TMC informs UCB immediately of the
         requirements that the regulatory authorities will impose. Any changes
         to the Specifications for other reasons must be agreed upon between the
         parties.

12.3     UCB warrants that the Product supplied to TMC hereunder shall be
         manufactured under conditions complying with current Good Manufacturing
         Practices as applicable in the European Union and USA and shall conform
         to the Specifications. UCB will send to TMC with each shipment of
         Product a corresponding certificate of analysis.


         THE WARRANTY MADE BY UCB UNDER TFHS ARTICLE 12.3 IS EXCLUSIVE AND IS
         MADE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING,
         BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR
         PURPOSE AND ANY IMPLIED WARRANTY ARISING OUT OF A COURSE OF DEALING,
         CUSTOM OR USAGE OR TRADE.

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ARTICLE 13 - MODIFICATIONS TO PROCESS

During the initial phase of the development period, prior to validation, UCB
will use its reasonable efforts to develop the process to make it feasible and
economic at large scale for the anticipated commercial production levels.
Thereafter, UCB will not make any modification to the process requiring prior
notice to (or approval of) regulatory authorities without the prior written
acceptance of TMC, such acceptance not being unreasonably withheld or delayed.
UCB will not make any other material modification to the process without the
prior written acceptance of TMC, such acceptance not being unreasonably withheld
or delayed.

UCB will document any modification to the process to enable TMC to notify the
FDA or any other regulatory authority deemed necessary of such modifications.

TMC and UCB agree to the Change Control Procedure provided in Annex 7.

ARTICLE 14 - ACCEPTANCE

Promptly after receipt of any shipment of Product, TMC shall control the
quantity and visually inspect the quality of the Product and analyze it to
establish its conformity to the Specifications.

No claim for visible defective quality or shortage in quantity of any individual
shipment of Product or other visible non-conformity of the Product shall be
valid unless made by written notice given within ten (10) working days from the
date of delivery. No claims for incorrect materials shall be valid unless made
by written notice given within sixty working (60) days from the date of
delivery. Such notice shall substantiate the reason of non-conformity.

UCB shall make up any shortfall and/or replace and/or rework (in accordance with
a qualified procedure) any non-conforming Product, at no additional cost to TMC.
Subject to Article 24 of this Agreement, UCB's liability to TMC for
non-conforming Product shall be limited to the replacement of such Product free
of charge. Upon UCB's instructions, TMC shall destroy or return at UCB's cost
(including import duties) the non-conforming Product.

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                                                                              11

If there is any dispute as to whether any shipment fails, in whole or in part,
to meet the requirements hereof, such dispute shall be resolved by an
independent testing organization of recognized repute within the pharmaceutical
industry in the United States of America. The expenses of such organization
shall be borne by the party against whom the decision is rendered.

ARTICLE 15 - COMPLIANCE WITH LAWS AND REGULATIONS.

TMC and UCB shall comply with applicable laws and regulations of government
agencies of the United States of America and the European Union. UCB shall
maintain all necessary permits for the conduct of activities related to the
Product that UCB undertakes pursuant to this Agreement.

ARTICLE 16 - REGULATORY COMPLIANCE AND APPROVALS.

Unless otherwise agreed, UCB shall at its expense make any and all filings and
take any other actions with respect to the regulatory authorities for the
development and production of the Product in compliance with cGMP and maintain
any and all documentation in accordance with the terms of this Agreement. At
TMC's request, UCB shall provide access to Batch Production Records and any
other documentation as requested by TMC to support regulatory approvals or
compliance.

ARTICLE 17 - AUDITS.

To ensure compliance with applicable laws and regulations of regulatory bodies,
TMC or its designee is entitled, with a reasonable notice and during working
hours, to conduct an appropriate audit or inspection in UCB's facilities in
Braine and review the corresponding documentation. Moreover, UCB will inform TMC
immediately of any inspection by the regulatory authorities that might take
place in relation with the development and production of the Product, if any. In
order to confirm that all royalties were paid in accordance with this Agreement,
on thirty (30) days' prior written notice to TMC, UCB and its certified public
accountants and other auditors shall have full access to the books and records
of TMC relevant to confirm such royalty payments, and shall have the right to
make copies therefrom at UCB's expense. UCB, its certified public accountants
and other auditors shall have such access at all reasonable times and from time
to time during normal business hours (but no more than once


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                                                                              12

during any calendar year). Prompt adjustment shall be made by the proper Party
to compensate for any errors or omissions disclosed by such audit. UCB shall
bear the costs of such audit, unless such audit reveals that the royalties paid
by TMC for the audited period was less than ninety-five percent (95%) of the
royalties actually due hereunder for such period, in which case TMC shall
reimburse UCB in full for its reasonable costs incurred in connection with such
audit. Any royalty payment not challenged within two (2) years after it is paid
shall be deemed to be correct, and shall no longer be subject to challenge.

ARTICLE 18 - TERM AND TERMINATION.

18.1     Expiration. Unless otherwise terminated in accordance with the terms
         herein, this Agreement shall be effective as from the date of signature
         of this Agreement by both Parties and shall terminate on the seventh
         (7th) anniversary of the First Sale Date, as notified by TMC in
         writing. Thereafter, it shall be automatically renewed for consecutive
         periods of three (3) years, unless a Party hereto serves the other
         Party a written notice of at least one (l) year prior the expiration of
         the initial term or of any renewal term, as the case may be.

18.2     Termination for Cause. In the event of a material breach of this
         Agreement by either Party and such Party's failure to remedy such
         breach within thirty (30) days after receiving notice thereof from the
         non-breaching Party which specifies the circumstances that constitute
         the breach, then the non-breaching Party may terminate this Agreement
         with immediate effect upon written notice to the breaching Party.

18.3     TERMINATION UPON BANKRUPTCY. This Agreement may be terminated by either
         Party with immediate effect upon the filing of a petition in
         bankruptcy, insolvency or reorganization against or by the other Party,
         or such other Party becoming subject to a composition for creditors,
         whether by law or agreement, or such other Party going into
         receivership or otherwise becoming.

ARTICLE 19 - EFFECT OF TERMINATION

19.1     EFFECTS OF TERMINATION

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         In the event of expiration or termination of the Agreement for whatever
         reason (other than breach of this Agreement by UCB),

         19.1.1   the fees for the development program incurred through such
                  date of expiration or termination will be due in full within
                  thirty (30) days following such expiration or termination.

         19.1.2   In addition, (i) TMC shall purchase from UCB all inventories
                  of Product meeting the Specifications, manufactured by UCB
                  based on the forecasted quantities of Product for the
                  current calendar quarter and the two calendar quarters
                  thereafter, based on TMC's then-current forecast (the
                  "Forecasted Quantities") and/or Purchase Orders delivered by
                  TMC to UCB prior to such expiration or termination, to the
                  extent that such Purchase Orders exceed the Forecasted
                  Quantities, at the then current price; (ii) all inventories
                  of quality control released process intermediates
                  manufactured by UCB based on the Forecasted Quantities of
                  Product at a price equal to their proportionate price of
                  Product; and (iii) all raw materials previously purchased by
                  UCB to meet the Forecasted Quantities of Product, at UCB's
                  purchase cost. TMC shall have the right to request from UCB
                  that it complete all work in progress at the time, and the
                  resulting Product shall then be purchased by TMC in
                  accordance with this Agreement.

         In the event of expiration or termination of the Agreement for breach
         of this Agreement by UCB, the fees for the development program incurred
         through such date of expiration or termination will be due in full
         within thirty (30) days following such expiration or termination. In
         addition, if TMC exercises its option to buy UCB's inventories and work
         in process, then TMC shall purchase such items in accordance with
         Section 19.1.2 above.

19.2     SURVIVALS

         Upon expiration or termination of this Agreement, all fights and
         obligations of the Parties hereunder shall immediately cease, except as
         to Articles 15, 16, 17, 19, 21 (royalty obligation only), 22, 23, 24,
         27 and 30 which shall survive in accordance with their terms.

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


19.3     RETURN OF CONFIDENTIAL INFORMATION UPON TERMINATION

         Upon expiration or termination of this Agreement, each Party shall
         promptly return to the other Party, at the other's request, any and all
         Confidential Information of the other Party then in its possession or
         under its control, except if such information is covered under
         surviving license rights granted by TMC to Third Parties.

19.4     ROYALTY PAYMENTS

In the event this Agreement expires or is terminated by TMC prior to the ten
(10th) anniversary of the First Sale Date (other than based on a breach of this
Agreement by UCB), UCB shall transfer the UCB Technical Information to a Third
Party(ies) designated by TMC, in order for such Third Party(ies) to act as
suppliers of Product for TMC. In consideration for such transfer of UCB
Technical Information, TMC shall pay to UCB royalties on an annual basis on
Product from the date of such termination until the tenth (10th) anniversary of
the First Sale Date. Such royalties shall be [**] of the amount paid by TMC for
its purchases of the Product manufactured by such Third Party during such
period; PROVIDED, HOWEVER, that if this Agreement is terminated by TMC based on
a breach of this Agreement by UCB, such royalties shall be waived and such
transfer of UCB Technical Information shall be royalty-free.

ARTICLE 20 - S-NDA.

After UCB has submitted its final milestone report, the Parties will negotiate
in good faith a timeline and a table of contents of a Drug Master File
supporting the filing of a S-NDA at the FDA for the Product. It is understood
that such filing shall require full co-operation between the Parties and that
the Parties will use their best efforts in acting so.

ARTICLE 21 - EXCLUSIVITY OF SUPPLY

Pursuant to article 2.2, the exclusivity of supply is eighty percent (80%)
during the entire period of the Agreement. If TMC, one of its Affiliates or a
Third Party (other than the second supplier established pursuant to Section 2.2
above) is able to supply Product to TMC with equivalent quality to the UCB
Product (where such Product is not manufactured by the second supplier

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                                                                              15

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


established pursuant to Section 2.2 above), at a price at least [**] below UCB's
price, and UCB does not wish to meet the price decrease, TMC shall no longer be
obligated to purchase eighty percent (80%) of its supply at UCB. If UCB meets
such price decrease, such new price shall replace the prices and price
adjustments under Section 9.2 above, subject to whatever further adjustments may
be mutually agreed to in writing between the Parties.

In addition, TMC shall no longer be obligated to purchase eighty percent (80%)
of its supply at UCB if (A) either: (i) UCB does not accept a firm order placed
by TMC for Product with requested delivery dates at least sixty (60) days after
the date on which TMC placed such order; or (ii) Product previously delivered by
UCB was repeatedly found not to conform to the Specifications for such Product,
or UCB repeatedly and materially fails to deliver the Products by the
agreed-upon dates; and (B) UCB has not cured such situation described in (A)(i)
or (ii) above within six (6) months after receiving written notice thereof from
TMC.

ARTICLE 22 -  PROPRIETARY RIGHTS

All data, information and results, including reports, files and other materials
made available by UCB to TMC or generated or derived by UCB as a result of the
development performed hereunder (excluding information and results concerning
the Product) shall remain the exclusive property of UCB. All information and
results concerning the Product shall remain the exclusive property of TMC.

ARTICLE 23 -  CONFIDENTIAL INFORMATION

23.1     MUTUAL CONFIDENTIALITY UNDERTAKING.

         From time to time during the ten-n of this Agreement, the Parties will
         disclose or make available to each other Confidential Information in
         connection with the activities contemplated hereunder.

         Each Party hereby agrees that it will use Confidential Information
         belonging to the other Party solely for the purpose(s) for which it was
         disclosed hereunder; and that it will not disclose Confidential
         Information belonging to the other Party to any Third Party (other


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         than its employees and/or consultants reasonably requiting such
         Confidential Information for purposes of this Agreement who are bound
         by written obligations of non disclosure and limited use at least as
         stringent as those contained herein) without the express prior written
         consent of the other party, except to regulatory authorities to the
         extent required by law or by applicable regulations.

         Any Confidential Information reasonably classifiable as a trade secret
         shall, as between the parties and their employees, remain a trade
         secret and be fully protected as such in spite of any failure by the
         Disclosing Party to constantly admonish the Receiving Party of the
         trade secret nature of the information disclosed or because of any
         failure of the Disclosing Party to pursue an active course of conduct
         designed to inform the Receiving Party or its employees that the
         secrets and information are to remain confidential.

23.2     PUBLICITY.

         The Parties further agree that except as otherwise expressly required
         by law, they will not publicly announce or otherwise disclose any of
         the terms and conditions of this Agreement without the express prior
         written consent of the other Party; provided that the foregoing shall
         not prohibit or restrict in any manner, and no consent shall be
         required, for any such public announcement or disclosure by a party in
         connection with any financing, strategic transaction or relationship,
         acquisition or disposition involving such party or as otherwise
         required by law. Neither Party will use the names of the other Party or
         any of its employees in any advertising, promotional or sales materials
         relating to Product or otherwise, except as required by law or
         regulatory authorities, without the express prior written consent of
         the other Party.

ARTICLE 24 - INDEMNIFICATION

24.1     INDEMNITIES IN FAVOR OF TMC

         UCB shall defend, indemnify and hold TMC, its Affiliates and the
         officers, directors and employees of each harmless from and against any
         and all claims, demands, loss, damage, liabilities, settlement amounts,
         costs or expenses whatsoever (including reasonable

<PAGE>   17

                                                                              17


         attorneys' fees and costs) arising from any claim, action or
         proceeding made or brought against such party by a Third Party as a
         result of (a) a defect occurring in the manufacture or processing,
         prior to the delivery of the Product to TMC; (b) provided the claim is
         made within the time periods set out in Article 14, non conformity of
         the Product to the Specifications; or (c) any claim that the process
         used by UCB to manufacture the Product infringes on the intellectual
         property rights of a Third Party.

24.2     INDEMNITIES IN FAVOR OF UCB

         TMC shall defend, indemnify and hold UCB, its Affiliates and the
         officers, directors and employees of each harmless from and against any
         and all claims, demands, loss, damage, liabilities, settlement amounts,
         costs or expenses whatsoever (including reasonable attorneys' fees and
         costs) arising from any claim, action or proceeding made or brought
         against such party by a Third Party as a result of (a) a defect
         occurring in the handling, processing, storage or transportation or any
         other matter whatsoever, after delivery of the Product to TMC, or (b)
         the sale or use the Product or the Product, including intellectual
         property rights relating thereto, except as a result of a defect of the
         Product or infringement claim for which UCB is liable pursuant to
         Article 24.1

24.3     LIMITATIONS

         The indemnification obligations provided for in this article shall be
         contingent upon the following additional terms and conditions:

         (i) the Party claiming indemnification shall have promptly given the
         indemnifying Party timely notice of the facts giving rise to such claim
         and reasonable co-operation, information and assistance in connection
         therewith;

         (ii) the indemnifying Party shall have sole control and authority with
         respect to the defense, settlement or compromise of the claim against
         the indemnified Party; provide , however, that the indemnifying Party
         may not enter into any settlement which imposes liability or
         restrictions on the indemnified Party without the prior written consent
         of the indemnified Party, such consent not to be unreasonably withheld
         or delayed.

<PAGE>   18

                                                                              18

24.4     CONSEQUENTIAL LOSSES.

         EXCEPT FOR THIRD PARTY CLAIMS FOR PERSONAL INJURY RESULTING FROM THE
         PRODUCTS, NOTWITHSTANDING ANY OTHER PROVISION HEREOF TO THE CONTRARY,
         NEITHER PARTY SHALL BE LIABLE TO THE OTHER PARTY FOR ANY SPECIAL,
         INCIDENTAL, INDIRECT, CONSEQUENTIAL OR EXEMPLARY DAMAGES, SUCH AS LOSS
         OF REPUTATION OR LOSS OF REVENUE OR PROFIT, EVEN IF SUCH PARTY WAS
         AWARE OF SUCH DAMAGES OR LOSSES.

24.5     INSURANCE

         During the term of this Agreement, both Parties will, each for their
         respective liability, secure and maintain a comprehensive general
         liability insurance policy providing sufficient coverage for personal
         injury (including as a result of product liability) and property
         damage, at the level as is usual and customary in the pharmaceutical
         industry to procure. A certificate with regard to said policies will be
         delivered to the other Party, at request

ARTICLE 25 - ASSIGNMENT AND DELEGATION

Neither this Agreement nor any rights hereunder may be assigned or licensed by
either Party, without the prior written consent of the other party, except for
assignments or sublicenses to: (i) Affiliates of the assigning or sublicensing
Party; or (ii) an acquiror of all or substantially all of the stock or assets of
the assigning or sublicensing Party which are related to the Product, whether
through purchase, merger, consolidation or otherwise,. Assignments and
sublicenses under (i) and (ii) shall occur freely by simple notice to the other
Party.

ARTICLE 26 - FORCE MAJEURE

Neither Party hereto shall be liable for damages, nor shall this Agreement be
terminable or cancelable by reason of any delay or default in such party's
performance hereunder if such default or delay is caused by events beyond such
Party's reasonable control ("force majeure")

<PAGE>   19

                                                                              19

including, but not limited to, acts of God, regulation or law or other action of
any government or agency thereof, war or insurrection, civil commotion,
destruction of production facilities or materials by earthquake, fire, flood or
storm, labor disturbances, epidemics, or failure of suppliers, public utilities
or common carriers.

Each Party shall endeavor to resume its performance hereunder as soon as
reasonably possible if such performance is delayed or interrupted by reason of
force majeure.

ARTICLE 27 -  APPLICABLE LAW - JURISDICTION

This Agreement shall be governed by and interpreted in accordance with the laws
of France, excluding the Vienna Convention on the International Sales of Goods
(dated 11 April 1980).

All disputes arising out of or relating to this Agreement shall be finally
resolved by arbitration conducted in the English language in Paris, France under
the commercial arbitration rules of the United Nations Commission on
International Trade Law. Each Party shall appoint an arbitrator and the two
arbitrators so appointed shall jointly appoint a third arbitrator; provided,
however, that if they cannot agree (or if one Party refuses to appoint an
arbitrator), then this third arbitrator shall be appointed by the President of
the International Chamber of Commerce, Paris. Both Parties shall bear equally
the cost of the arbitration (exclusive of legal fees and expenses, all of which
shall be allocated to the Party which does not prevail, as determined by the
arbitrators). All decisions of the arbitrator(s) shall be final and binding on
both Parties and enforceable in any court of competent jurisdiction.
Notwithstanding anything contained in this Section to the contrary, each Party
shall have the right to institute judicial proceedings against the other Party
or anyone acting by, through or under such other Party, in order to enforce the
instituting Party's rights hereunder through reformation of contract, specific
performance, injunction or similar equitable relief.

ARTICLE 28 - SEVERABILITY

Should any part of this Agreement be held unenforceable or in conflict with the
applicable laws or regulations of any jurisdiction, the invalid or unenforceable
part or provision shall be replaced with a provision which accomplishes, to the
extent possible, the original business purpose of

<PAGE>   20

                                                                              20


such part or provision in a valid and enforceable manner, and the remainder of
this Agreement shall remain binding upon the Parties hereto.

ARTICLE 29 - ENTIRE AGREEMENT

This Agreement (including the Annexes hereto) constitutes the entire
understanding between the Parties with respect to the subject matter hereof and
supersedes all prior agreements, negotiations, understandings, representations,
statements and writings relating to it or any part thereof.

No modification, alteration, waiver or change in any of the terms of this
Agreement shall be valid or binding upon the Parties hereto unless made in
writing and signed by both Parties.

ARTICLE 30 - NOTICES

Any notice required or permitted to be given under the terms of this Agreement
shall be in writing, to the attention of Vice President, Manufacturing and
Product Quality on behalf of TMC and to the attention of General Manager on
behalf of UCB, and shall be sufficiently given if mailed by registered mail
postage prepaid or given by telefax or delivery to the Party for whom it is
intended at the address indicated in the preamble or to such other address as
either Party hereto may from time to time advise the other Party by notice in
writing to the addresses first above given.

Any notice given as aforesaid shall be deemed to have been given on the day on
which it was delivered, if delivered, or on the tenth business day excluding
Saturday, Sunday and statutory holidays, following the date on which it was
mailed, if mailed, provided that if there is a postal interruption due to
strike, slow down or other causes, notice shall be given by delivery only. Any
Party hereto may change its address or contact person for service from time to
time by notice given in writing.

<PAGE>   21
                                                                              21


ARTICLE 31 - REPRESENTATIONS AND WARRANTIES

Each Party represents and warrants to the other that (i) the execution, delivery
and performance by such Party of this Agreement has been duly authorized by all
requisite corporate action on the part of such Party, and (ii) this Agreement
has been duly executed and delivered by such Party and constitutes the valid and
binding agreement of such Party, enforceable against such Party in accordance
with its terms.

ARTICLE 32 - MISCELLANEOUS

No waiver of any default hereunder by either Party or any failure to enforce any
rights hereunder shall be deemed to constitute a waiver of any subsequent
default with respect to the same or any other provision.

Headings are inserted for convenience and shall not affect the meaning or
interpretation of this Agreement or any clause thereof

Executed in two (2) original copies, each party acknowledging receipt of a
signed copy.


THE MEDICINES COMPANY INC.                UCB-BIOPRODUCTS S.A.


/s/ John M. Nystrom                       /s/ Werwer De Prycker
--------------------------------          ----------------------------------
By: John M. Nystrom                       By: Werwer De Prycker
Title: Vice President, Technical          Title: Director
       Ops.

/s/ John D. Richards                      /s/ Alain Scarso
--------------------------------          ----------------------------------
By: John D. Richards                      By: Alain Scarso
Title: Vice President,                    Title: Director
       Manufacturing and Product
       Quality

Date: December 20, 1999                   Date: December 16, 1999
Place: Cambridge, MA                      Place: Braine L' Alleund
       USA                                       Belguim