Document:

<Page>

                                                                    Exhibit 10.7

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

                                LICENSE AGREEMENT

                                       FOR

               INSTALLING NOVEL FUNCTIONAL GROUPS FOR THERAPEUTICS

                                     BETWEEN

                          MOMENTA PHARMACEUTICALS, INC.

                                       AND

                   THE REGENTS OF THE UNIVERSITY OF CALIFORNIA

                                   THROUGH THE

                             ERNEST ORLANDO LAWRENCE
                          BERKELEY NATIONAL LABORATORY

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                                                                       L-03-1370

                                TABLE OF CONTENTS

<Table>
<S>                                                                          <C>
1.   BACKGROUND                                                               1
2.   DEFINITIONS                                                              1
3.   LICENSE GRAND                                                            3
4.   INFORMATION RIGHTS                                                       4
5.   SUBLICENSING                                                             5
6.   LICENSE ISSUE FEE                                                        5
7.   ROYALTIES AND PAYMENTS                                                   6
8.   PERFORMANCE REQUIREMENTS                                                 8
9.   PROGRESS AND ROYALTY REPORTS                                             8
10.  BOOKS AND RECORDS                                                        9
11.  LIFE OF THE AGREEMENT                                                   10
12.  TERMINATION BY EITHER PARTY                                             11
13.  TERMINATION BY LICENSEE                                                 11
14.  DISPOSITION OF LICENSED PRODUCTS UPON TERMINATION                       11
15.  USE OF NAMES AND NONDISCLOSURE OBLIGATIONS                              11
16.  LIMITED WARRANTY                                                        12
17.  PATENTING AND FOREIGN RIGHTS                                            13
18.  PATENT INFRINGEMENT                                                     14
19.  WAIVER                                                                  15
20.  ASSIGNMENT                                                              16
21.  INDEMNIFICATION                                                         16
22.  LATE PAYMENTS                                                           17
23.  NOTICES                                                                 17
24.  U.S. MANUFACTURE                                                        18
25.  PATENT l1LAREJNNG                                                       18
26.  GOVERNMENT APPROVAL OR REGISTRATION                                     18
27.  EXPORT CONTROL LAWS                                                     18
28.  FORCE MAJEURE                                                           19
29.  MISCELLANEOUS                                                           19

Exhibit A                                                                    19
Exhibit B                                                                    20
Exhibit C                                                                    21
</Table>

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                                                                       L-03-1370

                              LICENSE AGREEMENT FOR
               INSTALLING NOVEL FUNCTIONAL GROUPS FOR THERAPEUTICS

This license agreement (the "Agreement") is entered into by The Regents of the
University of California, Department of Energy contract-operators of the Ernest
Orlando Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA
94720, ("Berkeley Lab"), and Momenta Pharmaceuticals, Inc. ("Licensee") having
its principal place of business at 43 MoultonStreet, Cambridge, MA 02138.

                                  1. BACKGROUND

1.1.    Certain inventions, generally characterized as Methods For Installing
        Novel Functional Groups On Cells And Cellular Products And Applications
        Thereof, as described in Berkeley Lab case [**], (the "Invention"), were
        made in the course of research at Berkeley Lab under Berkeley Lab's
        contract with the United States Department of Energy ("DOE").

1.2.    As DOE sponsored development of the Invention, this Agreement and the
        resulting license are subject to overriding obligations to the federal
        government pursuant to the provisions of the applicable law or
        regulations.

1.3.    Berkeley Lab wants the Invention developed and used to the fullest
        extent so that the general public enjoys the benefits of the
        government-sponsored research.

1.4.    Licensee wants to obtain certain rights from Berkeley Lab for the
        commercial development, manufacture, use, and sale of the Invention.

1.5.    Licensee is a "small business concern" as defined at Section 2 of Public
        Law 85-536 (15 U.S.C. 632).

Therefore the parties agree as follows:

                                 2. DEFINITIONS

2.1.    "Affiliate" means any legal entity that is controlled by Licensee. For
        the purposes of this definition, the term "control" means (i) beneficial
        ownership of at least fifty percent (50%) of the voting securities of a
        corporation or other entity with voting securities or (ii) a fifty
        percent (50%) or greater interest in the net assets or profits of a
        partnership or other entity without voting securities.

2.2.    "Broader Field" means the synthesis, production or modification of
        sugars and glycoconjugates in or on biological molecules for research,
        development and commercialization of human therapeutic applications.

2.3.    "Effective Date" means the date of execution by the last signing party.

2.4.    "Field Election Date" means the second anniversary of the Effective
        Date.

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                                                                       L-03-1370

2.5.    "Field of Use" means the Broader Field for two years from the Effective
        Date, and thereafter means the Specific Applications Field; provided,
        however, if Licensee extends its rights in accordance with paragraph
        3.3, "Field of Use" shall mean the Broader Field for the life of this
        Agreement. In either case, the Field of Use specifically excludes
        application of Licensed Patents to sale of reagents for life sciences
        research purposes (the "Excluded Field"). Licensee acknowledges that the
        Invention is licensed to a third party in that Excluded Field, and that
        the Field of Use shall not be interpreted to include any part of the
        Excluded Field.

2.6.    "Highly Inflationary Currency" means the currency of any economy with a
        cumulative inflation rate of 100% or more over the most recent three
        calendar years, as measured by consumer price indices published by the
        International Monetary Fund (International Financial Statistics),
        Washington, D.C.

2.7.    "Licensed Patents" means the following:

        2.7.1.  US Patent Number [**], entitled [**];

        2.7.2.  US Patent Number [**], entitled, [**];

        2.7.3.  US Patent Application Serial Number [**], entitled [**];

        2.7.4.  with respect to paragraphs 2.7.1 to 2.7.3, any corresponding
                foreign patent application or patent for which Licensee has met
                the requirements of paragraph 17.3;

        2.7.5.  any division, reexamination, continuation, continuation-in-part
                (excluding new matter contained and claimed in that
                continuation-in-part), or other application that is a successor
                to any of the foregoing applications; and

        2.7.6.  any patents issuing on any of the foregoing; and all renewals,
                reissues and extensions thereof.

2.8.    "Licensed Product" means any product, service or process that employs or
        is produced by the practice of any invention claimed in Licensed Patents
        or whose manufacture, use, practice, sale, offer for sale, or
        importation would constitute, but for the license Berkeley Lab grants to
        Licensee under this Agreement, an infringement of any Valid Claim in
        Licensed Patents in the country where such manufacture, use, practice,
        sale, offer for sale, or importation occurs.

2.9.    "Related Research Funding" means payments received by Licensee as
        reimbursement for research and development expenditures made or to be
        made by Licensee for an invention claimed in a Licensed Patent where
        such payments cover solely the actual costs of raw materials and labor,
        plus direct and indirect costs up to a maximum of [**]% ([**] percent)
        of the actual costs of raw materials and labor for such research.

2.10.   "Selling Price" for the purpose of computing royalties means the price
        received by Licensee, its Affiliate or its sublicensee for the sale of
        the Licensed Product in an arms-

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        length transaction, less the following: (a) allowances and adjustments
        actually credited or allowed to customers; (b) trade, quantity, cash and
        prompt payment discounts actually allowed and taken; (c) taxes levied on
        and/or other governmental charges imposed as to production, sales,
        transportation, delivery or use and paid or collected by or on behalf of
        Licensee; (d) costs of insurance, packing, and transportation from the
        place of manufacture to the customer's premises or point of
        installation; provided, however, that the costs described in clauses (c)
        and (d) may only be deducted from the Selling Price if, and to the
        extent that, they are separately identified in invoices. When a Licensed
        Product is not sold, but is otherwise disposed of, the Selling Price of
        that Licensed Product for the purposes of computing royalties is the
        selling price at which products of similar kind and quality, sold in
        similar quantities, are currently being offered for sale in arms-length
        transactions by Licensee. When such products are not currently being
        offered for sale by Licensee, the Selling Price of a Licensed Product
        otherwise disposed of, for the purpose of computing royalties, is the
        average selling price at which products of similar kind and quality,
        sold in similar quantities, are then currently being offered for sale by
        other manufacturers. When such products are not currently sold or
        offered for sale by Licensee or others, then the Selling Price, for the
        purpose of computing royalties, shall be negotiated by the parties in
        good faith based on the fair market value of the Licensed Product. Sales
        or other dispositions of Licensed Products between or among Licensee and
        any of its Affiliates or sublicensees for the purpose of subsequent
        resale to third parties ("Customers") shall not be included in the
        calculation of the Selling Price.

2.11.   "Specific Applications Field" means the synthesis, production or
        modification of sugars and glycoconjugates in or on biological molecules
        for research, development and commercialization of human therapeutic
        applications solely within the three specific therapeutic applications
        that are negotiated by the parties in accordance with paragraph 3.4.

2.12.   "Valid Claim" means a claim of any (1) issued patent in any country that
        (i) has not expired; (ii) Berkeley Lab has not disclaimed; (iii) has not
        been cancelled or superseded without reinstatement; and (iv) has not
        been revoked, held invalid, or otherwise declared unenforceable or not
        allowable by a governmental tribunal or patent authority of competent
        jurisdiction over such claim in such country from which no further
        appeal has or may be taken or (2) any United States patent application
        that has not been pending for more than five years or (3) any foreign
        patent application that has not been pending for more than seven years.

                                3. LICENSE GRANT

3.1.    Subject to the limitations set forth in this Agreement, Berkeley Lab
        grants to Licensee a nontransferable, limited (by the terms of
        paragraphs 3.5 and 3.6), exclusive, worldwide, royalty-bearing license,
        under Licensed Patents, only in the Field of Use, to make and have made,
        use and have used, offer and have offered for sale, sell and have sold,
        and import and have imported Licensed Products.

3.2.    Licensee's rights from the Effective Date until the Field Election Date
        are solely within the Broader Field.

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3.3.    Licensee may extend its rights to the Broader Field for the remainder of
        the term of this Agreement if it satisfies the following conditions by
        the Field Election Date: (1) reasonably demonstrates to Berkeley Lab
        that it has achieved the diligence milestones listed in Exhibit A; and
        (2) agrees to pay the election fee of $[**], which accrues on the Field
        Election Date, and pays the first installment in the amount of $[**] by
        the Field Election Date. The remaining two installments of $[**] are
        payable six months after the Field Election Date and twelve months after
        the Field Election Date, respectively. The election fee is
        non-refundable and is not an advance against royalties.

3.4.    If Licensee does not meet the requirements of paragraph 3.3, the Field
        of Use shall be narrowed as of the Field Election Date to cover three
        specific therapeutic applications. Licensee shall select the three
        specific applications from the list on Exhibit B, and shall send written
        notice of its selection to Berkeley Lab on or before the Field Election
        Date. The parties shall promptly negotiate in good faith to arrive,
        within 45 days of the Field Election Date, at mutually agreed on written
        definitions of the three selected therapeutic fields. Such definitions
        shall delineate with better specificity the applications described on
        Exhibit B and, so as to enable separate exclusive licensing, be
        sufficiently detailed as to be distinct from the non-elected therapeutic
        fields described on Exhibit B and other fields of use. Thereafter, the
        Field of Use will be the Specific Applications Field.

3.5.    Any license under this Agreement is subject to the following: (a) DOE's
        non-exclusive, royalty-free license for federal government purposes
        only, and (b) DOE's option to grant licenses either if reasonable steps
        to commercialize the Invention are not carried out or in order to meet
        federal regulations.

3.6.    Berkeley Lab expressly reserves the right to make and use the Invention
        and associated technology, and to allow other educational and non-profit
        institutions to do so, for noncommercial research and educational
        purposes. Without limiting the foregoing, nothing in this Agreement may
        be deemed to limit the right of Berkeley Lab to publish any technical
        data resulting from any research performed by Berkeley Lab relating to
        the Invention.

                              4. INFORMATION RIGHTS

4.1.    Unless it is legally prohibited from doing so by statute or regulation
        or contractual agreement with a research sponsor, Berkeley Lab upon
        Licensee's reasonable request shall disclose to Licensee any of its
        then-existing research data, clinical data, technical information and
        other information that is necessary or useful in connection with the
        manufacture, use or sale of any Licensed Product or the effective
        exercise or use of the Licensed Patents and that is reasonably
        accessible to the Berkeley Lab Technology Transfer Department. Licensee
        shall have the non-exclusive, worldwide, no-cost right to use all such
        information.

4.2.    Berkeley Lab shall notify Licensee of any future Berkeley-[**]
        Inventions (as defined below) within a reasonable period of time after
        any such invention is reported to the Berkeley Lab Technology Transfer
        Department, and in any case before Berkeley Lab enters into negotiations
        to license rights to such inventions to third parties. Licensee

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        acknowledges that this notification right does NOT require Berkeley Lab
        to license to Licensee any rights to ANY future inventions. For the
        purposes of this paragraph 4.2, "Berkeley-[**] Invention" means any
        patentable invention (or group of inventions so linked as to form a
        single general inventive concept), which (1) may be licensed to third
        parties by the Ernest Orlando Lawrence Berkeley National Laboratory,
        acting on behalf of The Regents of the University of California; and (2)
        was invented by [**], either alone or with others.

                                 5. SUBLICENSING

5.1.    Berkeley Lab also grants to Licensee the right to issue fee-bearing
        (only to the extent specified in paragraphs 7.1 and 7.3) sublicenses
        only in the Field of Use to make and have made, use and have used, offer
        and have offered for sale, sell and have sold, and import and have
        imported Licensed Products, so long as Licensee has current exclusive
        rights in its Field of Use. Licensee may only grant sublicenses that are
        no greater than the Field of Use to which Licensee is entitled. By way
        of illustration, if Licensee grants a sublicense before the Field
        Election Date, and Licensee does not thereafter extend its rights to the
        Broader Field in accordance with paragraph 3.3, then the sublicensee's
        rights after the Field Election Date can be no greater than the Specific
        Applications Field.

5.2.    Licensee shall incorporate terms into any sublicense Licensee grants
        that are sufficient to enable Licensee to comply with this Agreement and
        be consistent with all the rights and obligations due Berkeley Lab and
        the United States Government under this Agreement, including, without
        limitation, the license reserved by the United States Government.

5.3.    Licensee shall provide Berkeley Lab with a copy of each sublicense
        agreement executed under this Agreement. Licensee shall have the right
        to redact terms from the sublicense agreement that are irrelevant to
        this Agreement so long as it is apparent from the document furnished to
        Berkeley Lab that the redactions are irrelevant to this Agreement.

5.4.    If this Agreement terminates for any reason, each sublicense granted by
        the Licensee in accordance with this Agreement shall remain in effect
        subject to the terms of such sublicense and the terms of this Agreement.
        Licensee shall assign each sublicense and Berkeley Lab shall assume it.
        Notwithstanding the foregoing, Berkeley Lab shall not be obligated to
        assume any sublicense that: (1) is in a state of breach as yet uncured
        by the sublicensee or (2) conflicts with state or federal law or
        Berkeley Lab's contract with DOE. Berkeley Lab shall in no event be
        bound by any duties and obligations beyond those duties and obligations
        assumed by Berkeley Lab in this Agreement and shall have all rights
        against such sublicensee as provided with respect to Licensee in this
        Agreement.

                              6. LICENSE ISSUE FEE

6.1.    Licensee shall pay Berkeley Lab a license issue fee of $[**] (the
        "License Issue Fee"). This License Issue Fee accrues on the Effective
        Date, and Licensee shall pay this License Issue Fee as follows: $[**]
        within 5 days of the Effective Date, $[**] by February 15, 2003, and
        $[**] by August 15, 2003.

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6.2.    This License Issue Fee is non-refundable and is not an advance against
        royalties.

                            7. ROYALTIES AND PAYMENTS

7.1.    Licensee shall pay to Berkeley Lab an earned royalty of the Selling
        Price of each Licensed Product that Licensee, its Affiliate(s) or
        sublicensee(s) sells as follows, based on cumulative sales of all
        Licensed Products by Licensee, its Affiliate(s) and its sublicensees
        over the lifetime of this Agreement.

        7.1.1.  [**]% of Selling Price for cumulative sales of Licensed Products
                less than $[**];

        7.1.2.  [**]% of Selling Price for cumulative sales of Licensed Products
                between $[**] and $[**]; and

        7.1.3.  [**]% of Selling Price for cumulative sales of Licensed Products
                greater than $[**].

7.2.    Under this Agreement a Licensed Product is considered as sold when
        invoiced, or if not invoiced, when delivered to a third party Customer.
        But when the last patent covering a Licensed Product expires or when the
        license terminates, any shipment made on or before the day of that
        expiration or termination that has not been billed out before is
        considered as sold (and therefore subject to royalty). Berkeley Lab
        shall credit royalties that Licensee pays on a Licensed Product that the
        Customer does not accept or that the Customer returns.

7.3.    In addition to the payments made under paragraph 7.1, for each
        sublicense, Licensee shall pay Berkeley Lab the following:

        7.3.1.  [**]% of the up-front issue fee (excluding Related Research
                Funding), if any, that it receives from a sublicensee for any
                sublicense of the Licensed Patents;

        7.3.2.  [**]% of the annual maintenance fees (excluding Related Research
                Funding), if any, that it receives from a sublicensee for
                sublicense of the Licensed Patents; and

        7.3.3.  [**]% of milestone fees (excluding Related Research Funding), if
                any, paid to Licensee by a sublicensee; provided that
                achievement of such milestone, absent the license or sublicense,
                would infringe a Valid Claim of the Licensed Patents.

7.4.    Licensee shall pay to Berkeley Lab by August 31 of each year the
        difference between the earned royalties for that calendar year Licensee
        has already paid to Berkeley Lab (pursuant to paragraph 7.1) and the
        minimum annual royalty set forth in the applicable schedule below.
        Berkeley Lab shall credit that minimum annual royalty paid against the
        earned royalty due and owing for the calendar year for which Licensee
        made the minimum payment.

        7.4.1.  If Licensee does not extend its rights to the Broader Field
                beyond the Field Election Date (i.e., Licensee has rights solely
                in the Specific Application Field following the Field Election
                Date), then the minimum annual royalty is as follows:

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<Table>
<Caption>
                     Calendar Year                               Minimum Annual Royalty
                -----------------------------------------------  ----------------------
                <S>                                                      <C>
                2002                                                     $ [**]
                2003                                                     $ [**]
                2004                                                     $ [**]
                2005                                                     $ [**]
                2006                                                     $ [**]
                2007                                                     $ [**]
                2008                                                     $ [**]
                2009 and each year thereafter                            $ [**]
</Table>

        7.4.2.  If Licensee elects to extend its rights to the Broader Field
                beyond the Field Election Date in accordance with paragraph 3.3,
                then minimum annual royalty is as follows:

<Table>
<Caption>
                     Calendar Year                               Minimum Annual Royalty
                -----------------------------------------------  ----------------------
                <S>                                                      <C>
                2002                                                     $ [**]
                2003                                                     $ [**]
                2004                                                     $ [**]
                2005                                                     $ [**]
                2006                                                     $ [**]
                2007                                                     $ [**]
                2008                                                     $ [**]
                2009 and each year thereafter                            $ [**]
</Table>

7.5.    Licensee shall send payment for royalties accruing to Berkeley Lab
        quarterly together with its royalty report under paragraph 9.3.

7.6.    Licensee shall make checks payable to "The Regents of the University of
        California (Berkeley Lab/L-03-1370)." Licensee shall pay Berkeley Lab
        only in United States dollars. If a Licensed Product is sold for
        currency other than United States dollars (not including Highly
        Inflationary Currency), Licensee shall first determine the earned
        royalties in the foreign currency of the country in which the Licensed
        Product was sold and then convert them into equivalent United States
        dollars at the closing exchange rate published by THE WALL STREET
        JOURNAL on the last business day of the reporting period. If a Licensed
        Product is sold for a Highly Inflationary Currency, Licensee shall
        convert the sales subject to royalties into equivalent United States
        funds using the closing exchange rates in effect on the date of
        invoicing (or if no invoicing, of delivery) as published by THE WALL
        STREET JOURNAL. Licensee shall quote the exchange rate in the
        Continental method (local currency per U.S. dollar).

7.7.    Licensee may not reduce royalties payable by any taxes, fees, or other
        charges imposed on the remittance of royalty income. Licensee is also
        responsible for all bank transfer charges.

7.8.    If Licensee cannot promptly remit any royalties for sales in any country
        where a Licensed Product is sold because of legal restrictions, upon
        notice to Berkeley Lab, Licensee may deposit in United States funds
        royalties due Berkeley Lab to Berkeley Lab's account in a bank or other
        depository in that country. If Licensee is not permitted to deposit
        those

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        payments in U.S. funds under the laws of that country, Licensee may
        deposit those payments in the local currency to Berkeley Lab's account
        in a bank or other depository in that country.

7.9.    If a court of competent jurisdiction and last resort holds invalid any
        patent or any of the patent claims within a Licensed Patent in a final
        decision from which no appeal has or can be taken, Licensee's obligation
        to pay royalties based on that patent or claim will cease as of the date
        of that final decision. Licensee, however, shall pay any royalties that
        accrued before that decision or that are based on another patent or
        claim not involved in that decision.

7.10.   Licensee has no duty to pay Berkeley Lab royalties under this Agreement
        on a Licensed Product Licensee sells to the United States Government
        including any United States Government agency. Licensee shall reduce the
        amount charged for a Licensed Product sold to the United States
        Government by an amount equal to the royalty otherwise due Berkeley Lab.

                           8. PERFORMANCE REQUIREMENTS

8.1.    Licensee shall, itself or through its Affiliates or sublicensees,
        diligently proceed with the development, manufacture and sale of
        Licensed Products and shall diligently endeavor to market them within a
        reasonable time after the Effective Date in quantities sufficient to
        meet the market demand.

8.2.    Licensee shall make commercially reasonable efforts to obtain all
        necessary governmental approvals for the manufacture, use and sale of
        Licensed Products.

8.3.    If Berkeley Lab determines that Licensee has not met any of the
        diligence milestones listed in Exhibit C, taking into account any
        amendments or extensions pursuant to paragraph 8.4, then Berkeley Lab
        may either renegotiate those milestones in accordance with paragraph
        8.4, terminate this Agreement if the breach is not cured in accordance
        with the cure periods and other conditions of paragraph 12.1, or reduce
        Licensee's limited exclusive license to a nonexclusive license in the
        Field of Use.

8.4.    Licensee and Berkeley Lab by mutual written consent may amend or extend
        the requirements of Exhibit C at the written request of Licensee in
        response to legitimate business or technical reasons.

                         9. PROGRESS AND ROYALTY REPORTS

9.1.    Beginning May 31, 2003, and semi-annually thereafter, Licensee shall
        submit to Berkeley Lab a progress report covering Licensee's activities
        related to the development and testing of all Licensed Products and the
        obtaining of the governmental approvals necessary for marketing Licensed
        Products. Licensee shall make these progress reports until the later of
        the completion of the milestones listed in Exhibit C or commercial sales
        of any Licensed Product start.

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9.2.    The progress reports Licensee submits under paragraph 9.1 must include,
        but not be limited to, the following topics:

        9.2.1.  summary of work completed related to the requirements of
                Exhibit C;

        9.2.2.  key scientific discoveries;

        9.2.3.  summary of work in progress;

        9.2.4.  current schedule of anticipated milestones; and

        9.2.5.  market plans for introduction of Licensed Products; and

        9.2.6.  number of full-time equivalent employees or agents (FTEs)
                working on the development of Licensed Products and overall
                number of FTEs employed by Licensee.

9.3.    Upon the earlier of five years after the Effective Date or after the
        first commercial sale of a Licensed Product anywhere in the world,
        Licensee shall make quarterly royalty reports to Berkeley Lab on or
        before February 28, May 31, August 31 and November 30 of each year. Each
        royalty report must cover the most recently completed calendar quarter
        and must show for all sales (or other disposition in accordance with
        paragraph 2.9):

        9.3.1.  the Selling Price of each type of Licensed Product sold by
                Licensee;

        9.3.2.  the number of each type of Licensed Product sold;

        9.3.3.  the royalties, in U.S. dollars, payable under this Agreement on
                those sales;

        9.3.4.  the exchange rates used in calculating the royalty due;

        9.3.5.  the royalties on government sales that otherwise would have been
                due under paragraph 7.10; and

        9.3.6.  for each sublicense, if any:

                (1)   the sublicensee;

                (2)   the information set forth in paragraphs 9.3.1 to 9.3.5 for
                      that sublicensee's sales or other disposition of Licensed
                      Product.

9.4.    If no sales of Licensed Products have been made during any required
        reporting period, Licensee shall make a statement to this effect.

                              10. BOOKS AND RECORDS

10.1.   Licensee shall keep books and records accurately showing, to the extent
        sufficient to support the reports required in paragraph 9.2, work
        performed in satisfaction of the requirements of Exhibits A and C and
        all Licensed Products manufactured, used, sold,

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        imported or otherwise disposed of under the terms of this Agreement.
        Licensee shall preserve those books and records for at least five years
        from the date of the royalty payment to which they pertain and shall
        open them to representatives or agents of Berkeley Lab, during normal
        business hours, upon at least five (5) business days prior notice,
        solely to verify any reports and payments made or compliance in other
        respects under this Agreement. Inspections shall be limited to once per
        calendar year. Licensee shall render, at Berkeley Lab's expense, all
        assistance reasonably requested by Berkeley Lab for the purposes of
        carrying out such inspections and examination of Licensee's royalty
        payments and performance. Berkeley Lab shall maintain the results of any
        audit as Confidential Information of Licensee pursuant to paragraph
        15.3.

10.2.   Berkeley Lab shall bear the fees and expenses of Berkeley Lab's
        representatives performing the examination of the books and records. But
        if the representatives discover an error in royalties of more than 5% of
        the total royalties due for any year, then Licensee shall bear the
        reasonable and actual fees and expenses of these representatives and the
        difference between the earned royalties and the reported royalties
        (which shall be subject to the provisions of Article 22 (LATE
        PAYMENTS)). Notwithstanding the foregoing, if Berkeley Lab's
        representatives performing the examination are not independent certified
        public accountants and Licensee in good faith objects to the findings of
        such representatives, Licensee shall not be liable for the fees,
        expenses, and other payments of this paragraph 10.2, unless those
        findings are confirmed by independent certified public accountants.

                            11. LIFE OF THE AGREEMENT

11.1.   Unless otherwise terminated by acts of the parties in accordance with
        the terms of this Agreement, this Agreement is in force from the
        Effective Date and expires concurrently with the expiration, abandonment
        or final adjudication of invalidity of all Licensed Patents, whichever
        is later. Upon expiration (but not earlier termination) of this
        Agreement, Licensee shall have a non-exclusive, worldwide, no-cost right
        to use any information contained or described in the Licensed Patents
        and any information acquired by Licensee pursuant to paragraph 4.1.

11.2.   Any termination of this Agreement shall not affect the rights and
        obligations set forth in the following Articles:

        Article 10    Books and Records
        Article 11    Life of the Agreement
        Article 14    Disposition of Licensed Products on Hand upon Termination
        Article 15    Use of Names and Nondisclosure of Agreement
        Article 16    Limited Warranty
        Article 21    Indemnification
        Article 27    Export Control Laws
        Article 29    Miscellaneous
11.3.   Termination does not affect in any manner any rights of Berkeley Lab or
        Licensee arising under this Agreement before the termination.

                                    10 of 25
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                                                                       L-03-1370

                         12. TERMINATION BY EITHER PARTY

12.1.   In the event of a breach of any material term of this Agreement, then
        the non-breaching party may give written notice of such default
        ("Default Notice") to the breaching party. If the breaching party fails
        to cure that default and provide the non-breaching party with reasonable
        evidence of the cure within 90 days of the Default Notice (30 days in
        the case of breach of payment obligations by Licensee), the
        non-breaching party may terminate this Agreement and the licenses
        granted by a second written notice ("Termination Notice") to the
        breaching party after expiration of such cure period, and this Agreement
        shall automatically terminate on the deemed effective date of receipt
        (under Article 23) by the breaching party of the Termination Notice.

                           13. TERMINATION BY LICENSEE

13.1.   Licensee at any time may terminate this Agreement for any reason by
        giving written notice to Berkeley Lab. Licensee's termination notice
        must indicate whether Licensee has any inventory of Licensed Products.
        Licensee's termination of this Agreement will be effective 180 days
        after its notice.

              14. DISPOSITION OF LICENSED PRODUCTS UPON TERMINATION

14.1.   Within 45 days of termination of this Agreement for any reason, Licensee
        shall provide Berkeley Lab with a written inventory of all Licensed
        Products in process of manufacture or in stock. Licensee shall dispose
        of those Licensed Products within 120 days of termination. The sale of
        any Licensed Product within the 120 days is subject to the terms of this
        Agreement.

                 15. USE OF NAMES AND NONDISCLOSURE OBLIGATIONS

15.1.   In accordance with California Education Code Section 92000, Licensee
        shall not use in advertising, publicity or other promotional activities
        any name, trade name, trademark, or other designation of the University
        of California, nor shall Licensee so use "Ernest Orlando Lawrence
        Berkeley National Laboratory" or "Department of Energy" (including any
        contraction, abbreviation, or simulation of any of the foregoing)
        without Berkeley Lab's prior written consent.

15.2.   Neither party may disclose the terms of this Agreement to a third party
        without express written permission of the other party, except when
        required under either the California Public Records Act or other
        applicable law or court order. Notwithstanding anything to the contrary
        in this Article 15, (i) either party may disclose the existence of this
        Agreement and identity of the other party and the extent of the grant in
        Article 3 (License Grant); (b) Berkeley Lab may disclose the terms of
        this Agreement to the DOE; and (iii) Licensee may disclose the terms of
        this Agreement to any Affiliate, any sublicensee or potential
        sublicensee, or to any third party if necessary or desirable to assist
        Licensee in building its business, in each case under a written
        confidentiality agreement no less protective than the Mutual
        Nondisclosure Agreement between the parties effective as of July 12,
        2001 (the "Mutual NDA").

                                    11 of 25
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                                                                       L-03-1370

15.3.   All information Licensee is required to provide Berkeley Lab under this
        Agreement, including but not limited to information listed in paragraphs
        5.3, 9.1, and 9.3 of this Agreement, is deemed to be Confidential
        Information.

        15.3.1. Berkeley Lab will maintain the confidentiality of the
                Confidential Information, and will not use the Confidential
                Information for any purpose other than as necessary to
                administer this Agreement.

        15.3.2. The obligations of Berkeley Lab with respect to Confidential
                Information will not apply to information disclosed under this
                Agreement to the extent such information:

                15.3.2.1.   is disclosed in a proceeding to enforce Berkeley
                            Lab's rights under this Agreement;

                15.3.2.2.   is public knowledge at the time of disclosure or
                            becomes public knowledge through no wrongful act on
                            the part of Berkeley Lab;

                15.3.2.3.   is in Berkeley Lab's possession at the time of
                            disclosure;

                15.3.2.4.   is obtained by Berkeley Lab from a third party that
                            Berkeley Lab reasonably believes is not bound by
                            confidentiality obligations to Licensee;

                15.3.2.5.   is independently developed by Berkeley Lab without
                            reference to or reliance upon the information as can
                            be documented by written records; or

                15.3.2.6.   is required to be disclosed by Berkeley Lab to
                            comply with applicable laws or governmental
                            regulations, PROVIDED THAT the Berkeley Lab provides
                            prior written notice of such disclosure to the
                            Licensee and takes reasonable and lawful actions to
                            avoid and/or minimize the extent of such disclosure.

15.4.   The provisions of this Article 15 relating to confidentiality shall be
        in force and effect until 5 years following the termination of this
        Agreement.

                              16. LIMITED WARRANTY

16.1.   Berkeley Lab warrants to Licensee that it (a) is the sole owner of the
        Licensed Patents and the Invention, and (b) has the lawful right to
        grant the licenses granted herein. In addition to the notices and
        disclaimers in this Article 16 (LIMITED WARRANTY), Licensee hereby
        agrees and acknowledges that Berkeley Lab (i) has no responsibility or
        obligation to conduct any prior art or infringement search with respect
        to the Patent Rights; and (ii) Berkeley Lab makes no representation or
        warranty, and assumes no liability, with respect to the validity or
        non-infringement of the Patent Rights. In light of the foregoing, as of
        the Effective Date of this Agreement, the Licensing Manager in Berkeley
        Lab's Technology Transfer Department, who is responsible for the
        negotiation of this Agreement, is not aware

                                    12 of 25
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                                                                       L-03-1370

        of any third party intellectual property for which the practice of the
        Licensed Patents or the Invention would be an infringing act.

16.2.   This license and the associated Invention are provided WITHOUT WARRANTY
        OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR ANY OTHER
        WARRANTY, EXPRESS OR IMPLIED. BERKELEY LAB MAKES NO REPRESENTATION OR
        WARRANTY THAT LICENSED PRODUCTS WILL NOT INFRINGE ANY PATENT OR OTHER
        PROPRIETARY RIGHT.

16.3.   IN NO EVENT WILL EITHER PARTY BE LIABLE FOR ANY INCIDENTAL, SPECIAL OR
        CONSEQUENTIAL DAMAGES RESULTING FROM EXERCISE OF THIS LICENSE OR THE USE
        OF THE INVENTION OR LICENSED PRODUCTS, EVEN IF SUCH PARTY HAS BEEN
        ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

16.4.   Nothing in this Agreement may be construed as:

        16.4.1. a warranty or representation by Berkeley Lab as to the validity
                or scope of any of Berkeley Lab's rights in Licensed Patents;

        16.4.2. a warranty or representation that anything made, used, sold or
                otherwise disposed of under any license granted in this
                Agreement is or will be free from infringement of any patents
                other than Licensed Patents;

        16.4.3. an obligation to bring or prosecute actions or suits against
                third parties for patent infringement, except as specifically
                provided for in Article 18 (Patent Infringement); or

        16.4.4. a grant by implication, estoppel or otherwise of any license or
                rights under any patents of Berkeley Lab other than Licensed
                Patents, regardless of whether such patents are dominant or
                subordinate to Licensed Patents;

        16.4.5. an obligation to furnish any know-how not provided in Licensed
                Patents (except for information as provided in paragraph 4.1).

                        17. PATENTING AND FOREIGN RIGHTS

17.1.   Berkeley Lab shall prepare, file, prosecute and maintain patent
        applications and patents relating to inventions included in the Licensed
        Patents using patent counsel of its choice, and shall consult and
        cooperate with Licensee in connection therewith. Berkeley Lab shall copy
        Licensee promptly on all U.S.P.T.O. and foreign patent office actions so
        that Licensee shall be informed of the continuing prosecution.
        Notwithstanding the foregoing, Berkeley Lab may take any action useful
        or necessary to obtain and preserve its patent rights in Licensed
        Patents. Berkeley Lab shall use all reasonable efforts to amend any
        patent application to include claims and/or legal arguments reasonably
        requested by Licensee to protect the Licensed Products Licensee
        contemplates selling. To the extent such information is not available to
        the public, Licensee shall keep confidential documents from patent
        offices and patent related filings and associated drafts.

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                                                                       L-03-1370

17.2.   Licensee agrees to reimburse Berkeley Lab for Berkeley Lab's
        out-of-pocket patent preparation, filing, prosecution and maintenance
        costs. Such reimbursement includes costs of $[**] incurred through June
        14, 2002, and other costs not to exceed $[**] incurred prior to the
        Effective Date. Berkeley Lab shall provide Licensee with documentation
        of patenting costs incurred when invoicing Licensee for those costs.
        Licensee will reimburse Berkeley Lab within 30 days of invoicing.
        Licensee's obligation to reimburse patent costs continues for so long as
        this Agreement remains in effect, provided, however, that Licensee may
        terminate its obligations under this Agreement with respect to any given
        patent application or patent upon three months written notice to
        Berkeley Lab. Berkeley Lab shall use reasonable efforts to curtail
        patent costs when such a notice is received from Licensee. After such
        notice or when this Agreement terminates, Berkeley Lab may continue
        prosecution and/or maintenance of those application(s) or patent(s) at
        its sole discretion and expense; provided, however, that Licensee will
        have no further license or other right to them.

17.3.   Licensee may request that Berkeley Lab seek patent protection on the
        Licensed Patents in foreign countries if available. Berkeley Lab has no
        obligation to take action to file foreign patent applications unless
        Licensee provides written notice to Berkeley Lab at least six weeks
        before any applicable bar and that notice states which countries,
        regions or Patent Cooperation Treaty filing Licensee desires. If
        Licensee timely provides such notice, then Berkeley Lab shall timely
        make such foreign filings. The absence of the required notice from
        Licensee to Berkeley Lab acts as an election not to secure foreign
        rights.

17.4.   Berkeley Lab may file patent applications at its own expense in any
        country in which Licensee has not elected to secure patent rights. Those
        applications and resultant patents shall not be subject to this
        Agreement.

17.5.   If Berkeley Lab fails to prepare, file, prosecute or maintain patent
        applications or patents described in paragraphs 17.1 or 17.3, Licensee
        shall have the right, upon prior written notice to Berkeley Lab, to
        prepare, file, prosecute or maintain such patent applications or
        patents, at Licensee's expense, in the name of Berkeley Lab.

17.6.   Licensee shall promptly notify Berkeley Lab of any change in its status
        as a small business concern and of the first sublicense granted to an
        entity that does not qualify as a small business concern. A "small
        business concern" as used in this paragraph is as defined by the U.S.
        Patent and Trademark Office; currently, that is a company whose number
        of employees, including affiliates, does not exceed 500 persons (13
        C.F.R. 121.802).

                             18. PATENT INFRINGEMENT

18.1.   If Licensee learns of the substantial infringement of any of Licensed
        Patents, Licensee shall so inform Berkeley Lab in writing and shall
        provide Berkeley Lab with reasonable evidence of the infringement.
        During the period and in a jurisdiction where Licensee has exclusive
        rights under this Agreement, neither party may notify a third party of
        the infringement of any of Licensed Patents without first obtaining
        written consent of the other party, which consent shall not be
        unreasonably denied. Subject to paragraph 18.2, both

                                    14 of 25
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                                                                       L-03-1370

        parties shall use their reasonable efforts in cooperation with each
        other to resolve such infringement without litigation.

18.2.   Licensee may request that Berkeley Lab take legal action against the
        infringement of Licensed Patents in the Field of Use in which Licensee
        has exclusive rights under this Agreement. Licensee shall make that
        request in writing and include reasonable evidence of the infringement
        and damages to Licensee. If the infringing activity has not been abated
        within 90 days of that request, Berkeley Lab may elect to: (a) commence
        suit on its own account; or (b) refuse to participate in the suit.
        Berkeley Lab shall give written notice of its election to Licensee by
        the end of the 100th day after receiving notice of the request from
        Licensee. Licensee may thereafter bring suit for patent infringement
        only if Berkeley Lab elects not to commence suit and if the infringement
        occurred during the period and in a jurisdiction where Licensee has
        exclusive rights under this Agreement. If Berkeley Lab brings suit in
        accordance with this paragraph, Licensee may thereafter join such suit,
        at its own expense, and contribute up to fifty percent of the costs of
        such suit. If Licensee elects to bring suit in accordance with this
        paragraph, Berkeley Lab may thereafter join such suit, at its own
        expense, and contribute up to fifty percent of the costs of such suit.
        Subject to this paragraph 18.2, if required by law, each party shall
        permit any action under this paragraph to be brought in its name,
        including being joined as a nominal party-plaintiff, provided that the
        other party shall hold such party harmless from, and indemnify the such
        party against, any costs, expenses or liability that such party incurs
        in connection with such action.

18.3.   Such legal action as is decided upon must be at the expense of the party
        on account of whom suit is brought and all consequent recoveries belong
        to that party. But if Berkeley Lab and Licensee jointly bring legal
        action and fully participate in it, the parties must jointly share the
        expense and all recoveries shall be shared in proportion to the share of
        expense each party pays.

18.4.   Each party shall cooperate with the other in litigation proceedings
        instituted under this Agreement but at the expense of the party on
        account of whom suit is brought. The party bringing the suit will
        control that litigation, including the settlement thereof, subject to
        the right of Berkeley Lab to be represented by counsel of its choice in
        any suit brought by Licensee, it being understood that Licensee will
        still control litigation brought by it.

                                   19. WAIVER

19.1.   The waiver of any breach of any term of this Agreement does not waive
        any other breach of that or any other term.

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                                 20. ASSIGNMENT

20.1.   This Agreement is binding upon and shall inure to the benefit of (a)
        Berkeley Lab, its successors and assigns and (b) Licensee, its
        successors and permitted assigns. This Agreement is personal to the
        Licensee. Any attempt by Licensee to assign this Agreement is void
        unless Licensee obtains the prior written consent of Berkeley Lab;
        Berkeley Lab shall not unreasonably withhold that consent. Berkeley Lab
        acknowledges that it shall not be reasonable for Berkeley Lab to
        withhold its consent if the third party to whom Licensee desires to
        assign this Agreement has the expertise and financial ability to exploit
        the licenses granted under this Agreement (i.e., is not an entity with
        limited assets and personnel). Notwithstanding the preceding sentence,
        after Licensee has achieved the milestone described in Section 5 of
        Schedule C, Licensee may assign this Agreement, upon written notice to
        Berkeley Lab and without Berkeley Lab's consent, in conjunction with the
        sale or transfer of all or substantially all of its assets related to
        the commercialization of the Licensed Patents, or pursuant to a merger
        or consolidation, to or into an entity which has agreed in writing to be
        bound by all the terms and conditions of this Agreement.

                               21. INDEMNIFICATION

21.1.   Licensee agrees to indemnify, hold harmless and defend Berkeley Lab and
        the U.S. Government and their officers, employees, and agents; the
        sponsors of the research that led to the Invention; and the inventors of
        the patents and patent applications in Licensed Patents and their
        employers against any and all claims, suits, losses, damage, costs,
        fees, and expenses ("Claims") resulting from or arising out of
        Licensee's or its Affiliates' exercise of this license or its
        sublicensees' exercise of any sublicense, except to any indemnified
        party to the extent that Claims result from the gross negligence or
        willful misconduct of Berkeley Lab or its officers, employees, or
        agents. Licensee shall pay all costs incurred by Berkeley Lab in
        successfully enforcing this indemnification, including reasonable
        attorney fees. The indemnity set forth herein shall apply only if
        Licensee shall have been informed in writing as soon and as completely
        as practical by Berkeley Lab and/or the Government of the action
        alleging such Claim, the indemnified parties cooperate fully with
        Licensee in the defense of any such Claim, and Licensee shall have been
        given an opportunity, to the maximum extent afforded by applicable laws,
        rules, or regulations, to control its defense and settlement. Neither
        Licensee nor any indemnified party shall agree to any settlement of such
        Claim that does not include a complete release of the other party(-ies)
        from all liability with respect thereto or that imposes any liability,
        obligation or restriction on such other party(-ies) without such other
        party(-ies) consent unless required by final decree of a court of
        competent jurisdiction. Licensee may participate in the defense of any
        claim through its own counsel, and at its own expense.

21.2.   Licensee, at its sole expense, shall insure its activities related to
        this Agreement and obtain and keep in force Comprehensive or Commercial
        Form General Liability Insurance (contractual liability and products
        liability included) with limits as follows:

<Table>
        <S>                                                          <C>
        21.2.1. Each Occurrence                                      $ 4,000,000

        21.2.2. Products/Completed Operations Aggregate              $ 5,000,000
</Table>

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<Table>
        <S>                                                          <C>
        21.2.3. Personal and Advertising Injury                      $ 4,000,000

        21.2.4. General Aggregate (commercial form only)             $ 4,000,000
</Table>

21.3.   The coverages and limits referred to in this Article 21 do not in any
        way limit the liability of Licensee. Licensee shall furnish Berkeley Lab
        with certificates of insurance, including renewals, evidencing
        compliance with all requirements at least 30 days prior to the first
        commercial sale, clinical use, practice or distribution of a Licensed
        Product.

        21.3.1. If such insurance is written on a claims-made form, coverage
                shall provide for a retroactive date of placement on or before
                the Effective Date.

        21.3.2. Licensee shall maintain the general liability insurance
                specified during: (a) the period that the Licensed Product is
                being commercially distributed or sold by Licensee or by a
                sublicensee or agent of Licensee, and (b) a reasonable period
                thereafter, but in no event less than five years.

21.4.   The insurance coverage of paragraph 21.2 must:

        21.4.1. Provide for 30-day advance written notice to Berkeley Lab of
                cancellation or of any modification.

        21.4.2. Indicate that DOE, "The Regents of the University of California"
                and its officers, employees, students, agents, are endorsed as
                additional insureds.

        21.4.3. Include a provision that the coverages are primary and do not
                participate with, nor are excess over, any valid and collectible
                insurance or program of self-insurance carried or maintained by
                Berkeley Lab.

                                22. LATE PAYMENTS

22.1.   If Licensee does not make a payment to Berkeley Lab when due, Licensee
        shall pay to Berkeley Lab such reasonable administrative fees and the
        lesser of 10% simple interest per annum or the maximum permitted by law.

                                   23. NOTICES

23.1.   Any payment, notice or other communication this Agreement requires or
        permits either party to give must be in writing to the appropriate
        address given below or to such other address as one party designates by
        written notice to the other party. The parties deem payment, notice or
        other communication to have been properly given and to be effective (a)
        on the date of delivery if delivered in person; (b) on the fourth day
        after mailing if mailed by first-class mail, postage paid; (c) on the
        second day after delivery to an overnight courier service such as
        Federal Express, if sent by such a service; or (d) upon confirmed
        transmission by telecopier. The parties' addresses are as follows:

                                    17 of 25
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                For Berkeley Lab:

                Lawrence Berkeley National Laboratory
                Technology Transfer Department
                Mailstop 90-1070
                One Cyclotron Road
                Berkeley, California 94720
                Attention: Licensing Manager
                Fax: 510/486-6457
                Telephone: 510/486-6467

                For Licensee:

                Momenta Pharmaceuticals, Inc.
                43 Moulton Street
                Cambridge, MA 02138
                Attention: Vice President Licensing and Business Development
                Fax: 617/491-9701
                Telephone: 617/491-9700

                              24. U.S. MANUFACTURE

24.1.   To the extent required by law, Licensee shall have Licensed Products
        produced for sale in the United States manufactured substantially in the
        United States so long as Licensee has current exclusive rights in the
        Field of Use.

                               25. PATENT MARKING

25.1.   Licensee shall mark all Licensed Products made, used or sold under this
        Agreement, or their containers, in accordance with the applicable patent
        marking laws.

                     26. GOVERNMENT APPROVAL OR REGISTRATION

26.1.   If the law of any nation requires that any governmental agency either
        approve or register this Agreement or any associated transaction,
        Licensee shall assume all legal obligation to do so. Licensee shall
        notify Berkeley Lab if it becomes aware that this Agreement is subject
        to a U.S. or foreign government reporting or approval requirement.
        Licensee shall make all necessary filings and pay all costs, including
        fees, penalties, and all other costs associated with such reporting or
        approval process.

                             27. EXPORT CONTROL LAWS

27.1.   Licensee shall observe all applicable United States and foreign laws and
        regulations with respect to the transfer of Licensed Products and
        related technical data, including, without limitation, the International
        Traffic in Arms Regulations (ITAR) and the Export Administration
        Regulations.

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                                28. FORCE MAJEURE

28.1.   If a party's performance required under this Agreement is rendered
        impossible or unfeasible due to any catastrophes or other major events
        beyond its reasonable control, including, without limitation, the
        following, the parties are excused from performance: war, riot, and
        insurrection; laws, proclamations, edicts, ordinances or regulations;
        strikes, lockouts or other serious labor disputes; and floods, fires,
        explosions, or other natural disasters. When such events abate, the
        parties' respective obligations under this Agreement must resume.

                                29. MISCELLANEOUS

29.1.   The headings of the several sections are inserted for convenience of
        reference only and are not intended to be a part of or to affect the
        meaning or interpretation of this Agreement.

29.2.   This Agreement is not binding upon the parties until it is signed below
        on behalf of each party.

29.3.   No amendment or modification hereof shall be valid or binding upon the
        parties unless made in writing and signed on behalf of each party.

29.4.   This Agreement and the Mutual NDA, which is incorporated herein by
        reference, embody the entire and final understanding of the parties on
        this subject matter. They supersede any previous representations,
        agreements, or understandings, whether oral or written, relating to
        their subject matter.

29.5.   If a court of competent jurisdiction holds any provision of this
        Agreement invalid, illegal or unenforceable in any respect, this
        Agreement must be construed as if that invalid or illegal or
        unenforceable provision is severed from the Agreement, provided,
        however, that the parties shall negotiate in good faith substitute
        enforceable provisions that most nearly effect the parties' intent in
        entering into this Agreement.

29.6.   This Agreement must be interpreted under the laws of the state of
        California, without giving effect to any choice of law rules that would
        result in the application of laws of any jurisdiction other than those
        of the state of California, except that questions affecting the
        construction and effect of any patent shall be determined by the law of
        the country in which the patent is granted.

                                    19 of 25
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                                                                       L-03-1370

Berkeley Lab and Licensee execute this Agreement in duplicate originals through
their duly authorized respective officers in one or more counterparts, that
taken together, are but one instrument.

THE REGENTS OF THE UNIVERSITY             MOMENTA PHARMACEUTICALS, INC.
OF CALIFORNIA, THROUGH THE
ERNEST ORLANDO LAWRENCE
BERKELEY NATIONAL LABORATORY

By:     /s/ Piermaria Oddone              By:      /s/ Susan K. Whoriskey
        -----------------------------              -----------------------------
             (Signature)                                 (Signature)

By      Piermaria Oddone, Ph.D.           By       Susan K. Whoriskey, Ph.D.

Title   Deputy Laboratory Director        Title    Vice President, Licensing and
                                                   Business Development

Date    11/6/02
                                          Date     11-20-02

Approved as to form

By:     /s/ Glenn R. Woods
        -----------------------------
        GLENN R. WOODS
        LAWRENCE BERKELEY NATIONAL LABORATORY

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                                    EXHIBIT A

                Diligence Milestones for Rights to Broader Field

1.   Licensee shall have raised from inception at least $[**], in the aggregate,
     from the sale of Licensee's equity securities for its own account and/or
     from funding from corporate partners or sublicensees or otherwise.

2.   Licensee shall have hired [**] its senior management team, acquired
     expertise in [**] and employ a staff of [**] employees, of which at least
     [**] have advanced science degrees (Ph.D. or M.D.)

3.   Licensee shall have [**] using the Licensed Patents, either alone or in
     collaboration with other parties.

4.   Licensee shall have either (a) [**] such as a [**] in which [**] during the
     course of the [**], or (b) [**] Licensee [**] using the Licensed Patents
     [**].

                                    21 of 23
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                                                                       L-03-1370

                                    EXHIBIT B

           Therapeutic Applications within Specific Applications Field

[**]therapies

[**] therapies

[**] therapies, including [**]

[**] therapies

[**] therapies

[**] therapies [**]

[**] therapies

[**] therapies

[**] therapies

[**] therapies

[**] therapies

[**] therapeutic applications

And any other field upon which the parties may mutually agree.

                                    22 of 23
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                                                                       L-03-1370

                                    EXHIBIT C

                              Diligence Milestones

1.   Licensee shall permit an in-plant inspection by Berkeley Lab on or before
     November 2002 and thereafter permit in-plant inspections by Berkeley Lab at
     regular intervals with at least twelve (12) months between each inspection.

2.   Licensee shall have raised from inception at least $[**] by [**] from the
     sale of Licensee's equity securities for its own account.

3.   In the aggregate, Licensee shall have raised from inception at least $[**]
     by [**] from the sale of Licensee's equity securities for its own account
     and from funding from corporate partners or sublicensees or otherwise.

4.   Licensee shall fund, or shall cause its Affiliates, sublicensees and/or
     corporate partners to fund, no less than $[**] toward the research,
     development or commercialization of Licensed Products in each calendar year
     (pro-rated for partial years) beginning in the calendar year [**] and
     ending with calendar year [**].

5.   Licensee shall have [**], or shall have caused its Affiliates or
     sublicensees to [**], by [**]. In lieu of this requirement, Licensee shall
     fund, or shall cause its Affiliates, sublicensees and/or corporate partners
     to fund, no less than $[**] toward the research development or
     commercialization of Licensed Products in calendar year [**].

6.   Licensee shall fund, or shall cause its Affiliates, sublicensees and/or
     corporate partners to fund, no less than $[**] toward the research,
     development or commercialization of Licensed Products in each calendar year
     (pro-rated for partial years) beginning in calendar year [**] and shall
     continue such funding until the arms-length commercial sales of a Licensed
     Product total in the aggregate at least $[**].

                                    23 of 23<Page>

                                                                    Exhibit 10.8

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

                      DEVELOPMENT AND PRODUCTION AGREEMENT
                                       FOR
                        ACTIVE PHARMACEUTICAL INGREDIENT

                                     between

                              SIEGFRIED (USA), INC.
                             33 Industrial Park Road
                            Pennsville, NJ 08070 USA

                                       and

                                 SIEGFRIED LTD.
                              Untere Bruhlstrasse 4
                            4800 Zofingen SWITZERLAND

              (hereinafter collectively referred to as "SIEGFRIED")

                                       and

                          MOMENTA PHARMACEUTICALS, INC.
                                43 Moulton Street
                             Cambridge, MA 02138 USA

                     (hereinafter referred to as "MOMENTA")

<Page>

                                    RECITALS

This DEVELOPMENT AND PRODUCTION Agreement (the "Agreement") is entered into as
of the last date of signature set forth below (the "Effective Date") by and
between SIEGFRIED and MOMENTA.

WHEREAS, MOMENTA owns certain know-how pertaining to ENOXAPARIN and wishes to
have SIEGFRIED undertake the DEVELOPMENT and PRODUCTION of ENOXAPARIN under the
terms and conditions of this Agreement; and

WHEREAS, SIEGFRIED has expertise in developing and manufacturing active
pharmaceutical ingredients and wishes to undertake the DEVELOPMENT and
PRODUCTION of ENOXAPARIN on behalf of and for MOMENTA under the terms and
conditions of this Agreement;

NOW, THEREFORE, in consideration of the mutual covenants and promises contained
in this Agreement and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, MOMENTA and SIEGFRIED agree as
follows:

1.      DEFINITIONS

For the purpose of this Agreement, the following definitions shall apply:

1.1     "ENOXAPARIN" shall mean the active pharmaceutical ingredient commonly
known as enoxaparin sodium and more specifically described in Appendix A.

1.2     "KNOW-HOW" shall mean information and materials, including, without
limitation, ideas, concepts, discoveries, inventions, developments,
improvements, know-how, expertise, trade secrets, designs, devices, equipment,
process conditions, specifications, algorithms, notation systems, works of
authorship, computer programs, technologies, formulas, techniques, methods,
procedures, assay systems, applications, experimental results, data (including,
without limitation, analytical, toxicological, pharmacological, clinical,
bioequivalence and stability data), documentation, reports, sugars,
polysaccharides, heparinases, enzymes, reagents, glycoproteins, proteins,
peptides, glycoconjugates, primers, plasmids, vectors, expression systems,
cells, cell lines, antibodies, organisms, formulations, chemical compunds and
products, whether patentable or otherwise.

1.3     "MOMENTA KNOW-HOW" shall mean all KNOW-HOW controlled by MOMENTA as of
the date of this Agreement or developed or acquired by MOMENTA during the term,
but not in the performance of, this Agreement that pertains to ENOXAPARIN or
PRODUCT including, without limitation, the DEVELOPMENT of ENOXAPARIN or the
PRODUCTION of ENOXAPARIN or PRODUCT. MOMENTA KNOW-HOW shall not include NEW
KNOW-HOW.

1.4     "MOMENTA IP" shall mean all MOMENTA KNOW-HOW and all patents, patent
applications, copyrights, trade secrets and other intellectual property rights
controlled by MOMENTA covering the MOMENTA KNOW-HOW.

1.5     "SIEGFRIED KNOW-HOW" shall mean all KNOW-HOW (a) controlled by SIEGFRIED
as of the date of this Agreement or developed or acquired by SIEGFRIED during
the term, but not in the performance, of this Agreement that pertains to generic
development or production

<Page>

technologies or (b) developed or made and/or reduced to practice by SIEGFRIED
during the performance of this Agreement that pertains solely to generic
development or production technologies. SIEGFRIED KNOW-HOW shall not include NEW
KNOW-HOW.

1.6     "SIEGFRIED IP" shall mean all SIEGFRIED KNOW-HOW and all patents, patent
applications, copyrights, trade secrets and other intellectual property rights
controlled by SIEGFRIED covering the SIEGFRIED KNOW-HOW.

1.7     "NEW KNOW-HOW" shall mean all KNOW-HOW that pertains to ENOXAPARIN or
PRODUCT, the DEVELOPMENT of ENOXAPARIN, or the PRODUCTION of ENOXAPARIN or
PRODUCT that is developed or made and/or reduced to practice by SIEGFRIED
pursuant to this Agreement.

1.8     "NEW IP" shall mean all NEW KNOW-HOW and all patents, patent
applications, copyrights, trade secrets and other intellectual property rights
therein.

1.9     "DEVELOPMENT" shall mean the activities pertaining to the development of
the process for the PRODUCTION of PRODUCT including, without limitation, the
scale-up of the current process and delivery of samples of ENOXAPARIN, that are
described as Phase I - Laboratory under the Scope of Work in Appendix B.

1.10    "PRODUCTION" shall mean the activities pertaining to the production of
PRODUCT including, without limitation, the supply of quantities of PRODUCT, that
are described as Phase II - Pilot Production under the Scope of Work in Appendix
B.

1.11    "PRODUCT" shall mean ENOXAPARIN that meets the SPECIFICATIONS.

1.12    "SPECIFICATIONS" shall mean the specifications set forth in Appendix C
as the same may be amended by MOMENTA in accordance with the terms of this
Agreement.

1.13    "MASTER PRODUCTION RECORD" shall mean the formal set of instructions for
PRODUCTION of PRODUCT.

1.14    "GMP" shall mean those practices in the manufacture of pharmaceutical
products that are recognized as the current good manufacturing practices by the
FDA in accordance with FDA regulations, guidelines and other administrative
interpretations and rulings in connection therewith, including, but not limited
to those regulations cited in 21 C.F.R. Parts 210 and 211 and the International
Conference on Harmonization of Technical Requirements for Registration of
Pharmaceuticals for Human Use, Guidance for Industry Q7A Good Manufacturing
Practice Guidance for Active Pharmaceutical Ingredients, August 2001.

1.15    "ACT" shall mean the Federal Food, Drug and Cosmetics Act, together will
all rules and regulations promulgated thereunder, as the same may be amended
from time to time.

1.16    "FDA" shall mean the United States Food and Drug Administration.

1.17    "REGULATORY AUTHORITIES" shall mean those agencies or authorities
responsible for regulation of PRODUCT in the United States and oversees
including, without limitation, the FDA.

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1.18    "BATCH" shall mean the material resulting from a single manufacturing
order during a specific cycle of PRODUCTION.

1.19    "AFFILIATE" shall mean, with respect to a given party, any company,
corporation or other business entity controlling, controlled by, or under common
control with it at any time during the term of this Agreement. For the purpose
of this definition, the term "control" shall mean the possession of the power to
direct or cause the direction of the management and policies of an entity,
whether through the ownership of voting stock, by contract or otherwise. In the
case of a corporation, the term "control" shall mean the direct or indirect
ownership of at least fifty percent (50%) of the outstanding voting stock.

1.20    "CONFIDENTIAL INFORMATION" shall mean (a) in the case of MOMENTA, the
MOMENTA IP, NEW IP and any and all other information and materials disclosed by
MOMENTA to SIEGFRIED pursuant to the terms of this Agreement and (b) in the case
of SIEGFRIED, the SIEGFRIED IP and any and all other information and materials,
other than the NEW IP, disclosed by SIEGFRIED to MOMENTA pursuant to the terms
of this Agreement.

2.      DEVELOPMENT AND PRODUCTION

2.1     MOMENTA hereby engages SIEGFRIED to undertake the DEVELOPMENT and
PRODUCTION of ENOXAPARIN upon the terms and conditions set forth in this
Agreement and SIEGFRIED hereby accepts such engagement.

2.2     SIEGFRIED shall use commercially diligent efforts to undertake
DEVELOPMENT in accordance with the Scope of Work set forth in Appendix B as
Phase I - Laboratory, with the goal of meeting the time line for the completion
of DEVELOPMENT set forth in Appendix E.

2.3     SIEGFRIED shall use commercially diligent efforts to undertake
PRODUCTION in accordance with the Scope of Work set forth in Appendix B as Phase
II - Pilot Production, with the goal of meeting the time line for the completion
of PRODUCTION set forth in Appendix E and the goal of delivering [**] kilograms
of PRODUCT.

2.4     MOMENTA shall evaluate the samples of ENOXAPARIN delivered as part of
the DEVELOPMENT and shall evaluate the SPECIFICATIONS and MASTER PRODUCTION
RECORD prepared by SIEGFRIED for the PRODUCTION of PRODUCT. In the event that
MOMENTA is not satisfied with the samples of ENOXAPARIN or the SPECIFICATIONS or
MASTER PRODUCTION RECORD for the PRODUCTION of PRODUCT, SIEGFRIED shall continue
to work with MOMENTA on the process for the PRODUCTION of PRODUCT. SIEGFRIED
shall not initiate PRODUCTION until the foregoing activities shall have occurred
and SIEGFRIED shall have received written approval from MOMENTA of the
SPECIFICATIONS and MASTER PRODUCTION RECORD.

2.5     Laboratory studies conducted as part of the DEVELOPMENT may, but need
not, be performed in compliance with GMP. All DEVELOPMENT and PRODUCTION
associated with the actual manufacture of the [**] kilograms of PRODUCT shall be
performed in compliance with all applicable laws, regulations and rules
including, without limitation, GMP and the ACT. Further, all PRODUCT shall meet
the SPECIFICATIONS and all PRODUCTION shall be in accordance with the MASTER
PRODUCTION RECORD.

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2.6     SIEGFRIED shall perform all DEVELOPMENT and PRODUCTION at its facility
located in Pennsville, New Jersey.

2.7     PRODUCT shall be used by MOMENTA for stability, preclinical, clinical
and other development purposes.

3.      TRANSFER OF INFORMATION AND MATERIALS

3.1     MOMENTA shall be responsible for providing SIEGFRIED with such MOMENTA
KNOW-HOW as is reasonably necessary for SIEGFRIED to conduct the DEVELOPMENT and
PRODUCTION including, without limitation, the existing laboratory-scale process
for the PRODUCTION of ENOXAPARIN and the analytical methods for the PRODUCTION
of PRODUCT.

3.2     SIEGFRIED shall be responsible for the procurement of all raw materials
as are required for SIEGFRIED to conduct the DEVELOPMENT and PRODUCTION,
provided that MOMENTA shall be responsible for supplying SIEGFRIED, at no cost,
with the necessary quantities of heparin for DEVELOPMENT and with [**] kilograms
of heparin for PRODUCTION.

3.3     Upon any expiration or termination of this Agreement, for whatever
reason, SIEGFRIED shall forward to MOMENTA, upon MOMENTA's request, any
quantities of raw material supplied by MOMENTA or purchased by SIEGFRIED
pursuant to this Agreement, any quantities of ENOXAPARIN or PRODUCT, and any
quantities of any other material produced pursuant to this Agreement, such as
materials constituting work-in-progress. Notwithstanding the foregoing,
SIEGFRIED shall be entitled to retain such samples of the foregoing as are
required by law or are required in order for SIEGFRIED to comply with its
standard operating procedures.

4.      COLLABORATION AND REPORTING

4.1     SIEGFRIED shall perform the DEVELOPMENT and PRODUCTION in collaboration
with MOMENTA and shall keep MOMENTA regularly informed with respect to the
status of the DEVELOPMENT and PRODUCTION. Further, SIEGFRIED shall provide
MOMENTA with monthly written reports in a brief summarized form depicting the
progress of the work according to Appendices B and E.

4.2     Each party shall appoint one representative to be responsible for the
collaboration under this Agreement and all day-to-day communication between the
parties under this Agreement shall be addressed to such representatives. Any
report, approval or notice required or permitted to be given under or in
connection with this Agreement shall be deemed to have been sufficiently given
if in writing and sent by certified or registered mail, return receipt
requested, postage prepaid, sent by a nationally recognized overnight courier
service, or sent by hand delivery, to the representative for such party at the
address set forth below for such party. If a party changes its representative or
address, written notice shall be given promptly to the other party of the new
representative or address. Notice shall be deemed given on the third business
day after being sent in the case of delivery by mail, on the first business day
after being sent in the case of delivery by overnight courier, and on the date
of delivery in the case of delivery by hand.

The addresses of the parties and representatives are as follows:

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If to MOMENTA:       Momenta Pharmaceuticals, Inc.
                     43 Moulton Street
                     Cambridge, MA 02138

                     Representative: Joseph E. Tyler
                     E-Mail: jtyler@momentapharma.com

If to SIEGFRIED:     Siegfried (USA), Inc.
                     33 Industrial Park Road
                     Pennsville, NJ 08070

                     Representative: Scott M. Powers
                     E-Mail: scott.powers@siegfried-usa.com

5.      DOCUMENTATION AND RECORD KEEPING

5.1     With respect to each BATCH of PRODUCT, SIEGFRIED shall maintain and
submit to MOMENTA copies of the completed batch record, deviation reports,
out-of-specification records, investigation reports, in-process control raw
data, analytical data, certificates of analysis and MASTER PRODUCTION RECORD.

5.2     SIEGFRIED shall retain all raw data for thirteen (13) years from the
expiration or termination of this Agreement. After this period SIEGFRIED shall,
upon the timely request of MOMENTA within thirty (30) days after notification
from SIEGFRIED, forward such data to MOMENTA. Otherwise SIEGFRIED shall destroy
such raw data.

6.      QUALITY ASSURANCE AUDITS AND INSPECTIONS

6.1     SIEGFRIED's quality assurance group shall closely monitor and report on
the DEVELOPMENT of ENOXAPARIN and the PRODUCTION of PRODUCT in order to verify
compliance with GMP and the ACT.

6.2     MOMENTA shall have the right to request up to two (2) quality assurance
audits of the DEVELOPMENT of ENOXAPARIN and the PRODUCTION of PRODUCT in order
to verify compliance of DEVELOPMENT and PRODUCTION in accordance with the terms
of this Agreement. More frequent audits shall be permitted by SIEGFRIED in the
case of deficiencies as described Sections 13.1 and 13.2. All visits shall be
during normal business hours, shall not, either individually or when taken
together with all other such visits, unreasonably interrupt the operation of
SIEGFRIED, and shall be at the expense of MOMENTA. Further, all visiting
employees and consultants of MOMENTA shall have executed an appropriate
non-disclosure agreement or otherwise be under an obligation of confidentiality
consistent with Article 8 and shall comply at all times with all security and
other personnel and visitor procedures of SIEGFRIED.

6.3     Unless required by law, SIEGFRIED shall have no contact or communication
with any REGULATORY AUTHORITY regarding the DEVELOPMENT or PRODUCTION without
the prior written consent of MOMENTA and MOMENTA shall be solely responsible for
all such contacts and communications. In the event that SIEGFRIED receives any
contact or communication

<Page>

from any REGULATORY AUTHORITY pertaining to the DEVELOPMENT or PRODUCTION,
SIEGFRIED shall notify MOMENTA immediately and shall provide MOMENTA with copies
of any tangible manifestations of any such contact or communication within one
(1) business day thereafter. SIEGFRIED shall consult with MOMENTA regarding the
response to any such contact or communication and shall permit MOMENTA to
control and/or participate in such response. SIEGFRIED shall allow inspections
by REGULATORY AUTHORITIES of the DEVELOPMENT and PRODUCTION. In the event that
the DEVELOPMENT or PRODUCTION is inspected by a REGULATORY AUTHORITY, SIEGFRIED
shall inform MOMENTA prior to such inspection if at all possible or, if not
possible, immediately following such inspection.

7.      RIGHTS, INVENTIONS AND PATENTS

7.1     All MOMENTA IP shall be and remain the exclusive property of MOMENTA.
All SIEGFRIED IP shall be and remain the exclusive property of SIEGFRIED. All
NEW IP shall be "works made for hire" and the exclusive property of MOMENTA.
Further, all records of work performed by SIEGFRIED under this Agreement and all
reports required to be delivered by SIEGFRIED to MOMENTA under this Agreement
shall be "works made for hire" and the exclusive property of MOMENTA.
Notwithstanding the foregoing, solely to the extent necessary to comply with
applicable laws and regulations, SIEGFRIED shall have the right to keep one (1)
copy, or if so required one (1) original, of such records and reports.

7.2     MOMENTA, or its designee, shall have the sole right to file patent
applications relating to inventions included in the NEW KNOW-HOW. In the event
that MOMENTA, or its designee, seeks such patent protection, MOMENTA, or its
designee, shall bear the costs, including, but not limited to, attorneys fees,
associated with preparing, filing and prosecuting such patent applications and
for maintaining such patent protection as may be granted. In the event that
MOMENTA, or its designee, seeks such patent protection, SIEGFRIED shall provide
MOMENTA with reasonable assistance to obtain and defend such patent protection
at MOMENTA's expense.

7.3     If, during the course of this Agreement, SIEGFRIED, or any of its
employees or consultants, develops or makes and/or reduces to practice any item,
including, without limitation, any invention, included in the NEW KNOW-HOW,
SIEGFRIED hereby irrevocably assigns to MOMENTA all right, title and interest
it, or any of its employees, consultants and permitted subcontractors, may have
in such items included in the NEW KNOW-HOW.

7.4     SIEGFRIED further agrees that, upon request by MOMENTA and at MOMENTA's
expense, SIEGFRIED shall promptly execute, acknowledge or deliver any papers
deemed reasonably necessary by MOMENTA to document, enforce, protect, and
otherwise perfect such rights of MOMENTA, including, without limitation, all
documents necessary to obtain or perfect any intellectual property protection
and/or to effect an assignment of ownership of the same to MOMENTA.

7.5     SIEGFRIED represents that it has or will have agreements with all
employees, consultants and permitted subcontractors of SIEGFRIED who participate
in the DEVELOPMENT or PRODUCTION which effectively vest in SIEGFRIED any and all
rights which such persons or entities might otherwise have in the results of
their work and are adequate to permit SIEGFRIED to transfer such rights to
MOMENTA in accordance with this Article 7.

<Page>

7.6     MOMENTA hereby grants to SIEGFRIED a non-exclusive, non-sublicensable,
royalty-free license under the MOMENTA IP and NEW IP to conduct the DEVELOPMENT
and PRODUCTION during the term of this Agreement.

7.7     SIEGFRIED hereby grants to MOMENTA a non-exclusive, worldwide,
irrevocable, sublicensable, royalty-free license under the SIEGFRIED IP to
develop, make, have made, use, sell, have sold, offer for sale, import and have
imported ENOXAPARIN or PRODUCT and to otherwise exploit the NEW IP.

7.8     SIEGFRIED hereby agrees, during the term of this Agreement and for a
period of [**] years after the expiration or termination of this Agreement,
regardless of the cause of such expiration or termination, to work exclusively
with MOMENTA with respect to the DEVELOPMENT of ENOXAPARIN and/or the PRODUCTION
of ENOXAPARIN and PRODUCT.

7.9     To the extent that the NEW IP has application to products other than
unfractionated or low molecular weight heparin products, MOMENTA hereby grants
to SIEGFRIED a non-exclusive, worldwide, irrevocable, non-sublicensable,
royalty-free license under the NEW IP to develop, make, have made, use, sell,
have sold, offer for sale, import and have imported products that are not
unfractionated heparin or a low molecular weight heparin. For purposes of
clarity, the foregoing shall not be construed to constitute an implied license
to any MOMENTA IP.

8.      CONFIDENTIALITY

8.1     Each party agrees to retain in strict confidence and not to disclose,
divulge or otherwise communicate to any other person or entity any CONFIDENTIAL
INFORMATION of the other party, whether disclosed prior to, or after the date
hereof, and further agrees not to use any such CONFIDENTIAL INFORMATION for any
purpose, except pursuant to, and in order to carry out, the terms and objectives
of this Agreement, provided that each party may disclose CONFIDENTIAL
INFORMATION of the other party to the officers, directors, employees, agents,
consultants, permitted subcontractors or other representatives of the receiving
party or its AFFILIATES (the "Representatives"), who, in each case, need to know
such CONFIDENTIAL INFORMATION for purposes of the implementation and performance
by the receiving party of this Agreement and will use such CONFIDENTIAL
INFORMATION only for such limited purposes.

8.2     Each party agrees to use at least the same standard of care as it uses
to protect proprietary or CONFIDENTIAL INFORMATION of its own of comparable
sensitivity and to exercise every reasonable precaution to prevent and restrain
the unauthorized disclosure of such CONFIDENTIAL INFORMATION by any of its
Representatives.

8.3     Each party warrants that each of its Representatives to whom any
CONFIDENTIAL INFORMATION is revealed shall previously have been informed of the
confidential nature of the CONFIDENTIAL INFORMATION and shall have agreed to be
bound by the terms and conditions of this Article 8 applicable to the receiving
party.

8.4     The provisions of Section 8.1 shall not apply to any CONFIDENTIAL
INFORMATION disclosed hereunder which:
        a)      was known by the receiving party prior to its disclosure to the
receiving party by the other party, as evidenced by the prior written records of
the receiving party; or

<Page>

        b)      either before or after the date of disclosure to the receiving
party by the other party is lawfully disclosed to receiving party by an
independent, unaffiliated third party rightfully in possession of the
CONFIDENTIAL INFORMATION, provided that disclosure and use is in conformity with
the obligations of confidentiality and non-use imposed by such third party; or
        c)      either before or after the date of disclosure to the receiving
party by the other party becomes published or generally known to the public
through no fault or omission on the part of the receiving party or its
Representatives; or
        d)      is developed independently by the receiving party without use of
CONFIDENTIAL INFORMATION of the other party, as evidenced by the written records
of the receiving party; or
        e)      is required to be disclosed by the receiving party to comply
with applicable laws, to defend or prosecute litigation, or to comply with
governmental laws or regulations, provided that the receiving party provides
prior written notice of such disclosure to the other party and takes reasonable
and lawful actions to avoid and/or minimize the degree of such disclosure.

8.5     Notwithstanding anything herein to the contrary, the parties agree that
disclosure and use by MOMENTA or SIEGFRIED of CONFIDENTIAL INFORMATION of the
other party pursuant to any of the licenses granted in Sections 7.6 through 7.8
shall not be a violation of any term or condition contained in this Article 8,
provided that such disclosure or use is reasonably necessary in order to exploit
the applicable license granted.

8.6     Except as may be required by law or regulation, or in response to a
valid subpoena or other judicial order, neither party shall disclose the terms
of this Agreement without the prior written consent of the other party, except
that the parties may disclose the terms of this Agreement to their accountants
and attorneys, provided any such attorney or accountant agrees to be bound by
the confidentiality obligations of this Section 8.6.

8.7     Except as otherwise set forth in this Agreement, nothing herein shall be
construed as giving either party any right, title, interest in or ownership of
the CONFIDENTIAL INFORMATION of the other party. For the purposes of this
Agreement, any specific item disclosed as part of CONFIDENTIAL INFORMATION shall
not be deemed to be in the public domain or in the prior possession of the
receiving party merely because it is embraced by more general information in the
public domain or by more general information in the prior possession of the
receiving party.

8.8     The confidentiality obligations of the parties contained in this
Article 8 shall remain binding on both parties during the term of this Agreement
and for a period of fifteen (15) years after the expiration or termination of
this Agreement, regardless of the cause of such expiration or termination. The
parties acknowledge that any breach of this Article 8 will constitute
irreparable harm, and that the non-breaching party shall be entitled to specific
performance or injunctive relief to enforce this Article 8 in addition to
whatever remedies such party may otherwise be entitled to at law or in equity.

9.      TERMINATION

9.1     This Agreement shall commerce upon the Effective Date and, unless
terminated sooner in accordance with the terms and conditions provided herein,
shall remain in full force and effect until the date of the delivery and
acceptance of the [**] kilograms of PRODUCT by MOMENTA.

9.2     Either party may terminate this Agreement immediately by providing
written notice to the other party upon the occurrence of any of the following
events:

<Page>

        a)      the other party breaches a material obligation of this Agreement
and, after written notification from the non-breaching party, fails to remedy
the breach within fifteen (15) days of such written notification; or
        b)      either party reasonably determines that, for valid scientific or
technical reasons, the goals for the DEVELOPMENT or PRODUCTION cannot be
achieved within the parameters or timelines agreed to in Appendices B and E and
the parties cannot agree on a modification of such goals, parameters or
timelines within thirty (30) days of the date of the determination, it being
understood that each party shall be obligated to use good faith efforts to agree
on as minimal a modification of such goals, parameters or timelines as is
reasonably required by the scientific or technical obstacle; or
        c)      solely to the extent permitted by law, the other party opens
bankruptcy proceedings, goes into receivership, or allows its creditors to place
the company in receivership.

9.3     MOMENTA may terminate this Agreement, at any time, upon the giving of
thirty (30) days prior written notice to SIEGFRIED.

9.4     Upon any termination of this Agreement, the parties shall determine the
total amount of (a) the cost of all raw materials purchased by SIEGFRIED for
purposes of DEVELOPMENT and PRODUCTION plus (b) a reasonable estimate of the
cost of the labor associated with the proportion of the DEVELOPMENT and
PRODUCTION performed up to the date of the determination in the case of a
termination pursuant to clause (b) of Section 9.2 or up to the date of the
termination in the case of all other terminations of this Agreement (the "Actual
Cost"). For purposes of the foregoing calculation, fifty percent (50%) of the
fee set forth in Section 10.1 shall be attributed to the DEVELOPMENT and fifty
percent (50%) of the fee set forth in Section 10.1 shall be attributed to the
PRODUCTION. In the event of a termination by MOMENTA pursuant to clause (b) of
Section 9.2 or Section 9.3 or a termination by SIEGFRIED, subject to SIEGFRIED's
compliance with Section 3.3, SIEGFRIED shall be entitled to retain or receive
the Actual Cost. In determining whether an actual payment shall be due SIEGFRIED
from MOMENTA, all amounts previously paid by MOMENTA pursuant to Section 10.1
for DEVELOPMENT and PRODUCTION shall be taken into account. In the event that
MOMENTA shall have previously paid SIEGFRIED an amount greater than the Actual
Cost, SIEGFRIED shall pay MOMENTA an amount equal to the difference between the
amount previously paid by MOMENTA and the Actual Cost. In the event of a
termination by MOMENTA pursuant to clause (a) or (c) of Section 9.2, SIEGFRIED
shall not be entitled to any further payments from MOMENTA but, subject to
SIEGFRIED's compliance with Section 3.3, shall be entitled to retain all amounts
previously paid by MOMENTA pursuant to Section 10.1 for DEVELOPMENT and
PRODUCTION unless MOMENTA shall have previously paid SIEGFRIED an amount greater
than the Actual Cost. In any such case, SIEGFRIED shall pay MOMENTA an amount
equal to the difference between the amount previously paid by MOMENTA and the
Actual Cost.

9.5     All rights and obligations as set forth in Sections 3.3, 5.2, 7.1, 7.2,
7.3, 7.4, 7.5, 7.7, 7.8, 7.9, 9.4, 13.3, 13.4 and 13.5 and Articles 8 and 12
shall continue irrespective of any expiration or termination of this Agreement.

9.6     The waiver by the parties of any breach, covenant or condition herein
contained shall not be deemed to be a waiver of any subsequent breach of the
same or any other term, covenant or condition herein.

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10.     PAYMENT AND DELIVERIES

10.1    MOMENTA shall pay SIEGFRIED a total fee of [**] U.S. Dollars ($[**]) for
the DEVELOPMENT and PRODUCTION. Such fee shall become due in accordance with the
timetable set forth in Appendix D. SIEGFRIED shall invoice MOMENTA as payments
become due and MOMENTA shall pay such invoices within thirty (30) days
thereafter.

10.2    If, during the course of DEVELOPMENT, it becomes reasonably apparent to
SIEGFRIED that (a) circumstances exist which could not have been foreseen by the
parties or which were excluded from the assumptions made by both parties in
agreeing to the fee set forth in Section 10.1 and (b) such circumstances render
the completion of the DEVELOPMENT and PRODUCTION materially more costly than had
been foreseen by the parties, SIEGFRIED shall notify MOMENTA in writing. Upon
receipt of such notification, the parties shall use good faith efforts to agree
on as minimal a modification of the fee set forth in Section 10.1 as is
reasonably required by the unforseen or changed circumstance. If the parties
agree on an associated increase in cost, SIEGFRIED shall proceed with the
DEVELOPMENT and PRODUCTION. If the parties do not agree on an associated
increase in cost, SIEGFRIED shall have the right to proceed with DEVELOPMENT and
PRODUCTION or treat the circumstances as a technical obstacle and terminate this
Agreement in accordance with clause (b) of Section 9.2.

10.3    Delivery of ENOXAPARIN and PRODUCT shall be "ex works PENNSVILLE, NEW
JERSEY" as defined in the current INCOTERMS.

11.     SUBCONTRACTING

11.1    SIEGFRIED shall not be entitled to engage any subcontractor for the
DEVELOPMENT or the PRODUCTION without the prior written consent of MOMENTA. If a
subcontractor is appointed, SIEGFRIED shall be responsible for all work
performed by such subcontractor. The parties acknowledge in advance that
SIEGFRIED does not have the in-house capability to assay for certain biological
activities for quality control purposes, and that MOMENTA and SIEGFRIED will
mutually agree on appropriate third party subcontractors to conduct such assays
on behalf of SIEGFRIED.

11.2    In the event that MOMENTA requests a modification of the process
pertaining to the DEVELOPMENT of ENOXAPARIN or the PRODUCTION of PRODUCT for
which SIEGFRIED believes the expertise of a subcontractor is reasonably
necessary and MOMENTA is unwilling to approve such a subcontractor, SIEGFRIED
shall have the right to treat such refusal as a technical obstacle and terminate
this Agreement pursuant to clause (b) of Section 9.2.

11.3    MOMENTA shall be entitled to join any audit conducted by SIEGFRIED of a
supplier of raw material or of a subcontractor.

12.     WARRANTIES

12.1    Each party represents and warrants that, as of the effective date of
this Agreement, it is not a party to any agreement, contract, arrangement or the
like with any third party, or under any obligation or restriction, including,
without limitation, pursuant to its charter documents or by laws, which in any
way limits or conflicts with its ability to fulfill any of its obligations under
this Agreement.

<Page>

12.2    SIEGFRIED makes no representation or warranty that the processes used in
developing or producing ENOXAPARIN or PRODUCT or that the production, use or
importation of ENOXAPARIN or PRODUCT, would not infringe any patent or other
proprietary right belonging to a third party. Notwithstanding the foregoing,
SIEGFRIED represents and warrants to MOMENTA that, as of the effective date of
this Agreement, it has not received any notice from any third party that the
practice of the SIEGFRIED IP infringes any patent or other proprietary rights of
any third party and SIEGFRIED has no knowledge of any third party patent or
proprietary rights that might be infringed by the practice of the SIEGFRIED IP.
Further, SIEGFRIED represents and warrants to MOMENTA that it will not knowingly
use any infringing or misappropriated SIEGFRIED IP in the DEVELOPMENT or
PRODUCTION.

13.     PRODUCT QUALITY, INDEMNIFICATION AND INSURANCE

13.1    In the case of a material error by SIEGFRIED which results in an
inability to achieve the goals for the DEVELOPMENT or PRODUCTION within the
parameters or timelines agreed to in Appendices B and E, SIEGFRIED shall inform
MOMENTA immediately and exercise diligent efforts to correct the error so that
the goals for the DEVELOPMENT and PRODUCTION are achieved within the parameters
agreed to in Appendix B as soon as possible thereafter.

13.2    In the event that MOMENTA believes it is justified in rejecting PRODUCT
because it does not meet the requirements of Section 2.5, MOMENTA shall inform
SIEGFRIED accordingly with a written notice delivered within forty-five (45)
days from the date of receiving the PRODUCT. In any such case, the parties shall
repeat the disagreed upon sampling and analysis. Should MOMENTA still believe it
is justified in rejecting the PRODUCT following such repeated sampling and
analysis, MOMENTA shall have the right to engage an independent third party to
perform the disagreed upon sampling and analysis. Should the results show that
the PRODUCT does not meet the requirements of Section 2.5, SIEGFRIED shall
exercise diligent efforts to replace the PRODUCT as soon as possible thereafter
and shall be responsible for the cost of the replacement raw materials (other
than the heparin) and the sampling and analysis conducted by the independent
third party.

13.3    MOMENTA shall, at all times during the term of this Agreement and
thereafter, indemnify, defend and hold harmless SIEGFRIED, and its directors,
officers, employees and AFFILIATES (the "Other SIEGFRIED Indemnified Parties"),
from and against any and all third party product liability claims, proceedings,
demands and liabilities, of any kind whatsoever, including legal expenses and
reasonable attorneys' fees, arising out of the death of or injury to any person
or out of any damage to property resulting from the production, use or
consumption of any ENOXAPARIN or PRODUCT developed or produced pursuant to this
Agreement, excluding any such losses resulting from the failure of the PRODUCT
to meet the requirements of Section 2.5 or the negligence or misconduct of
SIEGFRIED.

13.4    SIEGFRIED shall, at all times during the term of this Agreement and
thereafter, indemnify, defend and hold harmless MOMENTA, and its directors,
officers, employees and AFFILIATES (the "Other MOMENTA Indemnified Parties"),
from and against any and all third party product liability claims, proceedings,
demands and liabilities, of any kind whatsoever, including legal expenses and
reasonable attorneys' fees, arising out of the death of or injury to any person
or out of any damage to property resulting from the production, use or
consumption of any ENOXAPARIN or PRODUCT developed or produced pursuant to this
Agreement where

<Page>

such losses result from the failure of the PRODUCT to meet the requirements of
Section 2.5 or the negligence or misconduct of SIEGFRIED.

13.5    Prior to the first use in humans of any ENOXAPARIN or PRODUCT developed
or produced pursuant to this Agreement, each party shall obtain and carry in
full force and effect commercial general liability insurance, including clinical
trial product liability insurance, which shall protect the other party with
respect to events covered by Sections 13.3 and 13.4. Such insurance shall be
written by a reputable insurance company authorized to do business in the United
States of America, shall list the other party as an additional named insured
thereunder, and shall require thirty (30) days written notice to be given to the
other party prior to any cancellation or material change thereof. The limits of
such insurance shall not be less than one million dollars ($1,000,000) per
occurrence with an aggregate of three million dollars ($3,000,000) for personal
injury, including death, and one million dollars ($1,000,000) per occurrence
with an aggregate of three million dollars ($3,000,000) for property damage.
Each party shall provide the other party with a certificate of insurance
evidencing the same.

13.6    MOMENTA shall, at all times during the term of this Agreement and
thereafter, indemnify, defend and hold harmless SIEGFRIED and the Other
SIEGFRIED Indemnified Parties, from and against any and all third party
liability claims, proceedings, demands and liabilities, of any kind whatsoever,
including legal expenses and reasonable attorneys' fees, arising out of any
alleged infringement of any patent or other intellectual property right held by
a third party in connection with the DEVELOPMENT or PRODUCTION or the use or
importation of any ENOXAPARIN or PRODUCT developed or produced pursuant to this
Agreement, excluding any such losses resulting from a breach by SIEGFRIED of the
representation and warranty set forth in Section 12.2.

13.7    SIEGFRIED shall, at all times during the term of this Agreement and
thereafter, indemnify, defend and hold harmless MOMENTA and the Other MOMENTA
Indemnified Parties, from and against any and all third party liability claims,
proceedings, demands and liabilities, of any kind whatsoever, including legal
expenses and reasonable attorneys' fees, arising out of any alleged infringement
of any patent or other intellectual property right held by a third party in
connection with the DEVELOPMENT or PRODUCTION or the use or importation of any
ENOXAPARIN or PRODUCT developed or produced pursuant to this Agreement where
such losses resulting from a breach by SIEGFRIED of the representation and
warranty set forth in Section 12.2.

13.8    If party or any of its associated indemnified parties intends to claim
indemnification under this Article 13, such party shall promptly notify the
other party in writing of the action, claim or other matter in respect of which
such party or any of its associated indemnified parties intends to claim such
indemnification. Such party shall permit, and, in order for any of its
associated indemnified parties to be indemnified pursuant to this Article 13,
shall cause such associated indemnified parties to permit, the other party to
solely control the defense and/or settlement of such action, claim or other
matter. No such action, claim or other matter shall be settled by such party or
any of its associated indemnified parties without the prior written consent of
the other party. Such party and its associated indemnified parties who seek to
be indemnified pursuant to this Article 13 shall fully cooperate with the other
party and its legal representatives in the investigation and defense of any
action, claim or other matter covered by the indemnification obligations of this
Article 13. Such party and its associated indemnified parties shall have the
right, but not the obligation, to be represented in such defense by counsel of
their own selection and at their own expense.

<Page>

13.9    In the event a claim is based partially on an indemnified claim and
partially on a non-indemnified claim, or based partially on a claim indemnified
by one party and partially on a claim indemnified by the other party, any
payments in connection with such claims are to be apportioned between the
parties in accordance with the degree of cause attributable to each party.

14.     MISCELLANEOUS

14.1    The working language for DEVELOPMENT and PRODUCTION under this
Agreement, the execution of this Agreement, and the interpretation of the terms
of this Agreement shall be the English language.

14.2    Neither this Agreement, nor any of the rights or obligations hereunder,
may be assigned by either party without the prior written consent of the other
party, except that (a) either party may assign this Agreement, whether by
operation of law, contract, or otherwise, without such consent, to a third party
who acquires all or substantially all of the assets of the assigning party or at
least 50% of the capital stock of the assigning party, whether by sale of stock,
merger or similar transaction, or otherwise acquires all or substantially all of
the business of the assigning party and (b) MOMENTA may assign this Agreement,
without such consent, to a third party who enters into an agreement with MOMENTA
pertaining to the development and commercialization of ENOXAPARIN, provided in
each instance that such third party agrees to be subject to and bound by all of
the terms and conditions of this Agreement. Notwithstanding the foregoing, in
the case of an assignment by MOMENTA to a major pharmaceutical company, such
major pharmaceutical company shall be entitled to self-insure under
Section 13.5. Any purported assignment in contravention of this Section 14.2
shall be null and void and of no effect.

14.3    Either party shall be excused from performing its obligation under this
Agreement if its performance is delayed or prevented by any cause beyond such
party's control, including but not limited to, act of God, fire, explosion,
weather, disease, war, insurrection, civil strife, riots, government action, or
power failure. Performance shall be excused only to the extent of and during the
reasonable continuance of such disability. Any deadline or time for performance
specified in an appendix to this Agreement that falls due during or subsequent
to the occurrence of any of the disabilities referred to herein shall be
automatically extended for a period of time equal to the period of such
disability. SIEGFRIED shall immediately notify MOMENTA if, by reason of any of
the disabilities referred to herein, SIEGFRIED is unable to meet any deadline or
time for performance specified in an appendix to this Agreement. The foregoing
shall not be construed to alter MOMENTA's rights under Section 9.3.

14.4    Nothing herein, or in any appendix to this Agreement, shall be deemed or
construed to constitute or create between the parties hereto a partnership,
joint venture, agency, or other relationship other than as expressly set forth
herein. Neither party shall be responsible for the acts or omissions of the
other party, and neither party will have authority to speak for, represent or
obligate the other party in any way without prior written authority from the
other party.

14.5    This Agreement and the appendices to this Agreement, which appendices
are deemed to be a part of this Agreement for all purposes, contain the full
understanding of the parties with respect to the subject matter hereof and
supersede all prior understandings and writings relating thereto. No waiver,
alteration or modification of any of the provisions hereof shall be binding
unless made in writing and signed by the parties.

<Page>

14.6    In the event that any term of this Agreement shall violate any
applicable statute, ordinance or rule of law in any jurisdiction in which it is
used, or otherwise be unenforceable, such provision shall be ineffective to the
extent of such violation without invalidating any other provision hereof.

14.7    Each party represents and warrants to the other that it has the legal
power, authority and right to enter into this Agreement and to perform its
respective obligations set forth herein. This Agreement has been duly executed
and delivered by each party and constitutes the valid and binding obligation of
such party, enforceable against such party in accordance with its terms.

14.8    This Agreement may be executed in counterparts, including signatures by
facsimile, each of which shall be deemed an original, but all of which together
shall constitute but one and the same Agreement.

14.9    This Agreement shall be governed and interpreted in accordance with the
laws of the State of New Jersey.

In WITNESS WHEREOF, the parties have had this Agreement signed by their duly
authorized representatives, all as of the effective date.

SIEGFRIED (USA), INC.                           SIEGFRIED LTD

By: /S/ DONALD D. BELL                           By: /s/ DENNIS P. BAUER
   --------------------------                      -----------------------------

Title:   President                              Title: VP - Business Areas (USA)
      -----------------------                         --------------------------

Date:    Oct. 6, 2003                           Date:  October 3, 2003
     ------------------------                        ---------------------------

MOMENTA PHARMACEUTICALS, INC.

By: /s/ JOSEPH E. TYLER
   --------------------------

TITLE: Vice President
      ---------------------------

DATE:  October 10, 2003
      ---------------------------

<Page>

                                   APPENDIX A.

                            Description of ENOXAPARIN

Product Name: Enoxaparin Sodium

Molecular formula: [**]

Molecular weight: [**]

Structural formula:

                                      [**]

CAS - number: [**]

<Page>

                                   APPENDIX B.

                           DEVELOPMENT and PRODUCTION

GENERAL

The following Scope of Work is based on MOMENTA's Request for Proposal for the
development and production of ENOXAPARIN dated February 14, 2003, the process
described therein, and additional technical information provided by MOMENTA.
Unforeseen circumstances and changes in the assumptions of the parties are dealt
with in Sections 9.2, 10.2 and 11.2 of the Agreement.

ASSUMPTIONS

The following set of assumptions form the basis for the Scope of Work:

The overall process yield will be [**].

SIEGFRIED will conduct [**].

SIEGFRIED will conduct [**].

SIEGFRIED will conduct [**].

SIEGFRIED will conduct [**].

SCOPE OF WORK

PHASE I - LABORATORY

[**] provided by MOMENTA.

[**] provided by MOMENTA and implement [**].

Identify [**].

Develop [**].

Deliver [**].

Characterize [**].

<Page>

Conduct safety testing on [**].

Screen [**].

Provide laboratory report on the development work conducted and the final
laboratory scale process.

PHASE II - PILOT PRODUCTION

Prepare [**] in accordance with the [**].

[**] with the exception of [**].

Produce [**].

[**], provide MOMENTA with all [**].

Conduct [**].

Provide [**].

Provide project summary report following completion of pilot production.

<Page>

                                   APPENDIX C.

                       Draft Specifications for ENOXAPARIN

<Table>
<Caption>
       TEST                         METHOD                 EP SPECIFICATIONS            USP SPECIFICATIONS
----------------------------------------------------------------------------------------------------------------
<S>                           <C>                     <C>                           <C>
Description                   Visual                  [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]

[**]                          [**]                    [**]                          [**]
</Table>

<Page>

                                   APPENDIX D.

                               Pricing Assumptions

-    Heparin will be provided to SIEGFRIED at no cost to SIEGFRIED.

-    The cost for the [**] will be $[**] per kilogram.

-    The third party cost associated with the performance of quality control
     assays of biological activities is excluded from the total due SIEGFRIED.

PAYMENT SCHEDULE:

-    [**] percent ([**]%) of the total cost due under Section 10.1 will be due
     on November 1, 2003, provided that Momenta and Siegfried may mutually agree
     to an acceleration of the initial work contemplated under this Agreement
     and an earlier payment of this amount.

-    [**] percent ([**]%) of the total cost due under Section 10.1 of the
     Agreement will be due [**].

-    The balance of the total due under Section 10.1 of the Agreement will be
     due upon completion of PRODUCTION.

<Page>

                                   APPENDIX E:

                                    Schedule

The following completion dates are conditioned upon MOMENTA's fulfilment of its
obligations to SIEGFRIED under Sections 3.1 and 3.2 of the Agreement on a timely
basis.

PHASE I COMPLETION DATE:     [**] from execution of the Agreement.

PHASE II COMPLETION DATE:    [**] from approval of MASTER PRODUCTION RECORD and
                             SPECIFICATIONS by MOMENTA

<Page>

                          Momenta Pharmaceuticals, Inc.
                                43 Moulton Street
                         Cambridge, Massachusetts 02138

                                    February 14, 2004

Mr. Scott M. Powers
Siegfried (USA), Inc.
33 Industrial Park Road
Pennsville, NJ 08070

Dear Scott:

Reference is made to the Development and Production Agreement for Active
Pharmaceutical Ingredient between Siegfried (USA), Inc. and Siegfried Ltd.
("SIEGFRIED") and Momenta Pharmaceuticals, Inc. ("MOMENTA") dated October 10,
2003 (the "Agreement"). Capitalized terms used herein and not otherwise defined
shall have the meanings given such terms in the Agreement.

MOMENTA hereby engages SIEGFRIED to undertake the additional development work
set forth on Appendix A to this Letter Agreement (the "ADDITIONAL DEVELOPMENT
WORK"). The ADDITIONAL DEVELOPMENT WORK shall be conducted under the terms and
conditions of the Agreement, with the following modifications:

     1.   SIEGFRIED shall use commercially diligent efforts to undertake the
          ADDITIONAL DEVELOPMENT WORK with the goal of completing the work
          within [**] of initiation of the work.

     2.   MOMENTA shall pay SIEGFRIED a total fee of [**] U.S. Dollars ($[**])
          for the ADDITIONAL DEVELOPMENT WORK. [**] percent ([**]%) of such fee
          shall be due and payable upon initiation of the work and the remaining
          [**] percent ([**]%) shall be due and payable upon the issuance of a
          final development report by SIEGFRIED which is reasonably satisfactory
          to MOMENTA. Invoicing and payment shall be in accordance with Section
          10.1 of the Agreement. For purposes of Section 9.4 of the Agreement,
          the foregoing fee shall be attributed to the ADDITIONAL DEVELOPMENT
          WORK.

     3.   MOMENTA shall be responsible for supplying the necessary quantities of
          heparin for the ADDITIONAL DEVELOPMENT WORK in accordance with Section
          3.2 of the Agreement.

<Page>

     4.   At the conclusion of the ADDITIONAL DEVELOPMENT WORK, or earlier if
          the parties so agree, the parties shall agree upon the production of
          ENOXAPARIN and/or PRODUCT to be undertaken by SIEGFRIED under the
          Agreement.

If the foregoing is in conformity with your understanding, please execute both
copies of this Letter Agreement and return one fully-executed copy to me.

                             Very truly yours,

                             /s/ JOSEPH E. TYLER
                              Joseph E. Tyler

Agreed and accepted:

SIEGFRIED (USA), INC.

By:  /s/ SCOTT POWERS    Feb. 18, 2004
   ----------------------------------------

SIEGFRIED LTD.

By:  /s/ DENNIS P. BAUER
   ------------------------------------------------

<Page>

                                   APPENDIX A

                                      [**]
                         WORK AT SIEGFRIEDM-ENOX PROJECT

STEP 1
[**]

   [**]
   [**]
   [**]
   Maintain [**]
   Maintain [**]
   [**]
   Will use[**]
   [**]
   [**]

STEP 2
[**]
      [**]
      [**]
      [**]
      [**]
      Will use [**]
      [**]
      [**]
      [**]
[**]
      [**]
      [**]

<Page>

[**]
      [**]
      [**]
      [**]
      [**]
      [**]
      [**]
      [**]
[**]
      [**]
      [**]

STEP 3

[**]
      [**]
      Use [**]
      [**]
      Current [**]
      Add [**]
      [**]
          Add [**]
          Complete [**]
          Start [**]
      [**]
[**]
      [**]
      [**]
      [**]
      [**]
      [**]

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00062-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00062-of-00352.parquet"}]]