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                                                                    Exhibit 10.2

                                                          CONFIDENTIAL TREATMENT
                                    GTC Biotherapeutics, Inc. has requested that
                                the marked portions of this document be accorded
                                   confidential treatment pursuant to Rule 24b-2
                                   promulgated under the Securities Exchange Act


                             COLLABORATION AGREEMENT

                                      among

                              GENZYME CORPORATION,

                         GENZYME TRANSGENICS CORPORATION

                                       and

                                    ATIII LLC

                           dated as of January 1, 1998

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                                TABLE OF CONTENTS

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ARTICLE 1.      DEFINITIONS ......................................................1

     1.1.   "Affiliate" ..........................................................1

     1.2.   "Behring" ............................................................2

     1.3.   "BLA" ................................................................2

     1.4.   "Centeon" ............................................................2

     1.5.   "Collaboration Product" ..............................................2

     1.6.   "Commercialization Costs" ............................................2

     1.7.   "Commercialization Plan" .............................................2

     1.8.   "Date of Execution" ..................................................2

     1.9.   "Development Costs" ..................................................3

     1.10.  "Development Plan" ...................................................3

     1.11.  "Development Program" ................................................3

     1.12.  "Distribution Margin" ................................................3

     1.13.  "Distributor's Discount" .............................................4

     1.14.  "Effective Date" .....................................................4

     1.15.  "Estimated Fully Absorbed Cost of Goods" .............................4

     1.16.  "Estimated Net Selling Price" ........................................4

     1.17.  "Field" ..............................................................4

     1.18.  "FDA" ................................................................4

     1.19.  "Fully Absorbed Cost of Goods" .......................................4

     1.20.  "GAAP" ...............................................................5

     1.21.  "Genzyme Patent Rights" ..............................................5

     1.22.  "Genzyme Technology" .................................................5

     1.23.  "Genzyme/GTC Patent Rights" ..........................................5

     1.24.  "Genzyme/GTC Technology" .............................................5

     1.25.  "GTC Licensed ATIII Patent Rights" ...................................5

     1.26.  "GTC Patent Rights" ..................................................5

     1.27.  "GTC Technology" .....................................................6

     1.28.  "Major Market Countries" .............................................6

     1.29.  "Manufacturer's Profit" ..............................................6
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                                   (continued)

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     1.30.  "Manufacturing Know-How" .............................................6

     1.31.  "Manufacturing Margin" ...............................................6

     1.32.  "Member" .............................................................6

     1.33.  "Net Profit" .........................................................6

     1.34.  "Net Sales" ..........................................................7

     1.35.  "New Facility" .......................................................7

     1.36.  "New Facility Costs" .................................................7

     1.37.  "Operating Agreement" ................................................8

     1.38.  "Patent Rights" ......................................................8

     1.39.  "Percentage Interest" ................................................8

     1.40.  "Program" ............................................................8

     1.41.  "Program Costs" ......................................................8

     1.42.  "Program Management Team" ............................................8

     1.43.  "Purchase Agreement" .................................................8

     1.44.  "Regulatory Approvals" ...............................................8

     1.45.  "Regulatory Scheme" ..................................................8

     1.46.  "SMIG" ...............................................................8

     1.47.  "SMIG Territory" .....................................................8

     1.48.  "Specifications" .....................................................9

     1.49.  "Steering Committee" .................................................9

     1.50.  "Technology" .........................................................9

     1.51.  "Territory" ..........................................................9

     1.52.  "Third Party" ........................................................9

     1.53.  "Transgenic Animal" ..................................................9

     1.54.  "Transgenic ATIII" ...................................................9

ARTICLE 2.      SCOPE AND STRUCTURE OF THE COLLABORATION .........................9

     2.1.   General ..............................................................9

     2.2.   Exclusive Relationship ..............................................10

     2.3.   Centeon Agreement ...................................................10

     2.4.   SMIG Agreement ......................................................11
</Table>

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                                TABLE OF CONTENTS
                                   (continued)

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ARTICLE 3.      GRANTS AND RESERVATIONS OF RIGHTS ...............................12

     3.1.   Licenses of Rights to ATIII LLC .....................................12
            3.1.1. Grants from GTC ..............................................12
            3.1.2. Grants from Genzyme ..........................................12
            3.1.3. ATIII LLC Undertakings; Sublicenses ..........................13
            3.1.4. Rights of ATIII LLC to Patent Rights or Technology Developed
                   Outside the Program ..........................................13

     3.2.   Sublicenses of Rights from ATIII LLC to GTC and Genzyme .............13

     3.3.   Reservation of Rights ...............................................14
            3.3.1. Reservation by GTC ...........................................14
            3.3.2. Reservation by Genzyme .......................................14

ARTICLE 4.      PROGRAM FUNDING; LLC INTEREST ...................................14

     4.1.   Program Funding Commitments .........................................14
            4.1.1. 1998 Funding .................................................14
            4.1.2. Funding After 1998 ...........................................14
            4.1.3. New Facility Costs ...........................................15
            4.1.4. Adjustment to Percentage Interest and Funding Commitment .....15

     4.2.   Program Funding Capital Contributions ...............................15
            4.2.1. Initial Capital Contributions ................................15
            4.2.2. Monthly Capital Contributions ................................15
            4.2.3. Quarterly Statements; Quarterly Reconciliation ...............15

     4.3.   Distributions .......................................................16

     4.4.   Sale and Purchase of LLC Interest ...................................16

     4.5.   Books of Account; Audit .............................................16

ARTICLE 5.      THE DEVELOPMENT PROGRAM .........................................17

     5.1.   Conduct of the Development Program ..................................17
            5.1.1. General ......................................................17
            5.1.2. Development Plan .............................................17
            5.1.3. Initial and Updated Development Plan .........................18
            5.1.4. Execution and Performance ....................................19
            5.1.5. Attendance at Regulatory Meetings ............................19

     5.2.   Development Information .............................................19
            5.2.1. Reports and Information Exchange .............................19
            5.2.2. Adverse Reaction Reporting ...................................19
            5.2.3. Clinical and Regulatory Audits ...............................19

     5.3.   Regulatory Approval Filings .........................................20

     5.4.   Facilities Visits ...................................................20

ARTICLE 6.      SALES, MARKETING AND ADMINISTRATIVE SERVICES ....................20

     6.1.   Commercialization Plans .............................................20
            6.1.1. General ......................................................20
            6.1.2. Initial and Updated Commercialization Plans ..................21

     6.2.   Exclusive Engagement ................................................21

     6.3.   Orders and Forecasting ..............................................22

     6.4.   Prices and Payment Terms; Costs .....................................22
            6.4.1. Prices .......................................................22
            6.4.2. Terms of Payment .............................................22
            6.4.3. Marketing and Distribution Expenses ..........................22

     6.5.   Responsibilities of Genzyme .........................................22

     6.6.   Responsibilities of ATIII LLC and GTC ...............................24

     6.7.   Third Party Distributors ............................................24

     6.8.   General and Administrative Services .................................24

ARTICLE 7.      MANUFACTURE AND SUPPLY ..........................................24

     7.1.   Process Development; Manufacturing Approvals ........................25

     7.2.   Manufacture and Supply of Collaboration Products ....................25
            7.2.1. General ......................................................25
            7.2.2. Manufacturing Facilities and Capacity Requirements ...........26
            7.2.3. Forecasts ....................................................26

     7.3.   Certificates of Analysis ............................................26

     7.4.   Certificates of Manufacturing Compliance ............................26

     7.5.   Access to Facilities ................................................27
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                                   (continued)

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ARTICLE 8.      MANAGEMENT ......................................................27

     8.1.   Program Management Team .............................................27
            8.1.1. General ......................................................27
            8.1.2. Development Program Functions ................................27
            8.1.3. Commercialization Functions ..................................28
            8.1.4. Minutes ......................................................29

     8.2.   Steering Committee ..................................................28
            8.2.1. General ......................................................28
            8.2.2. Functions ....................................................28
            8.2.3. Minutes ......................................................29

     8.3.   General Disagreements ...............................................29

ARTICLE 9.      INTELLECTUAL PROPERTY RIGHTS ....................................29

     9.1.   Ownership ...........................................................29
            9.1.1. Ownership and Assignment of Discoveries and Improvements .....30
            9.1.2. Ownership of Trademarks ......................................30
            9.1.3. Cooperation of Employees .....................................30

     9.2.   Filing, Prosecution and Maintenance of Patent Rights ................30
            9.2.1. Filing, Prosecution and Maintenance ..........................31
            9.2.2. Patent Filing Costs ..........................................31

     9.3.   Cooperation .........................................................31

     9.4.   Notification of Patent Term Restoration .............................31

     9.5.   No Other Technology Rights ..........................................32

     9.6.   Enforcement of Patent Rights; Defense of Infringement Actions .......32
            9.6.1. First Right to Respond .......................................32
            9.6.2. Sharing of Litigation and Settlement Expenses ................32
            9.6.3. Second Right to Respond ......................................32

ARTICLE 10.     CONFIDENTIALITY .................................................32

     10.1.  Nondisclosure Obligations ...........................................32

     10.2.  Terms of this Agreement; Press Releases .............................33

     10.3.  Publications ........................................................33

ARTICLE 11.     REPRESENTATIONS AND WARRANTIES ..................................34

     11.1.  Authorization .......................................................34

     11.2.  Intellectual Property Rights ........................................34

     11.3.  Warranties ..........................................................35
            11.3.1. Genzyme Warranties ..........................................35
            11.3.2. GTC Warranties ..............................................35

     11.4.  Disclaimer of Representations and Warranties ........................35

     11.5.  Limitation of Liability .............................................35

ARTICLE 12.     INDEMNITY .......................................................35

     12.1.  ATIII LLC Indemnity Obligations .....................................35

     12.2.  Insurance ...........................................................36

ARTICLE 13.     TERM AND TERMINATION ............................................36

     13.1.  Term ................................................................36

     13.2.  Termination .........................................................36
            13.2.1. For Certain Material Breaches ...............................36
            13.2.2. For Failure to Make a Milestone Payment .....................36
            13.2.3. For Convenience .............................................37
            13.2.4. Upon Bankruptcy .............................................37

     13.3.  Effects of Termination ..............................................37
            13.3.1. For Certain Material Breaches ...............................37
            13.3.2. For Failure to Make a Milestone Payment .....................38
            13.3.3. For Convenience .............................................39
            13.3.4. Upon Bankruptcy .............................................40
            13.3.5. Fair Value ..................................................41

     13.4.  Inventory ...........................................................41

     13.5.  Survival of Rights and Duties .......................................42
</Table>

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                                   (continued)

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ARTICLE 14.     MISCELLANEOUS ...................................................42

     14.1.  Cooperation .........................................................42

     14.2.  Exchange Controls ...................................................42

     14.3.  Withholding Taxes ...................................................42

     14.4.  IRS Transfer Pricing Adjustments ....................................43

     14.5.  Interest on Late Payments ...........................................43

     14.6.  Force Majeure .......................................................43

     14.7.  Assignment ..........................................................43

     14.8.  Severability ........................................................43

     14.9.  Notices .............................................................44

     14.10. Applicable Law ......................................................45

     14.11. Arbitration .........................................................45
            14.11.1. General ....................................................45
            14.11.2. Procedure ..................................................45

     14.12. Injunctive Relief ...................................................46

     14.13. Entire Agreement ....................................................46

     14.14. Headings ............................................................47

     14.15. Independent Contractors .............................................47

     14.16. Waiver ..............................................................47

     14.17. Counterparts ........................................................47
</Table>

                                       -v-
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                             COLLABORATION AGREEMENT

     THIS COLLABORATION AGREEMENT dated as of January 1, 1998 (the "AGREEMENT")
is made among Genzyme Corporation, a Massachusetts corporation having its
principal place of business at One Kendall Square, Cambridge, Massachusetts
02139 ("GENZYME"), Genzyme Transgenics Corporation, a Massachusetts corporation
having its principal place of business at Five Mountain Road, Framingham,
Massachusetts 01701 ("GTC") and ATIII LLC, a Delaware limited liability company
having its principal place of business at One Kendall Square, Cambridge,
Massachusetts 02139 ("ATIII LLC"). Genzyme, GTC and ATIII LLC are sometimes
referred to herein individually as a "PARTY" and collectively as the "PARTIES."

                                 R E C I T A L S

     A.     GTC is developing recombinant human antithrombin III ("ATIII"),
produced in the milk of transgenic goats. ATIII is a principle inhibitor of
blood coagulation serine proteases, such as thrombin and Factor Xa and certain
other blood components, and assists in the maintenance of homeostatic balance.
Decreased levels of ATIII occur in individuals having a genetic or an acquired
deficiency. Acquired deficiencies can result from obstetrical or surgical
procedures, including without limitation coronary artery bypass grafting
("CABG") procedures, and disease states, including without limitation sepsis and
septic shock, acute liver failure, disseminated intravascular coagulation,
burns, multiple trauma, organ transplantation and hemodialysis. GTC is currently
developing ATIII for the treatment of ATIII deficiencies.

     B.     Genzyme has expertise in the areas of development and marketing of
bio-pharmaceutical products.

     C.     ATIII LLC has been organized by GTC and Genzyme as the vehicle for a
joint venture between GTC and Genzyme to develop and commercialize the
Collaboration Products (as defined herein) throughout the Territory (as defined
herein).

     NOW THEREFORE, in consideration of the premises and of the covenants herein
contained, the Parties mutually agree as follows:

                             ARTICLE 1. DEFINITIONS

     For purposes of this Agreement, the terms defined in this Article shall
have the meanings specified below. Certain other capitalized terms are defined
elsewhere in this Agreement.

     1.1.   "AFFILIATE" shall mean any corporation or other entity which
controls, is controlled by, or is under common control with a Party. A
corporation or other entity shall be regarded as in control of another
corporation or entity if it owns or directly or indirectly controls more than
fifty percent (50%) of the voting stock or other ownership interest of the other
corporation or entity, or if it possesses, directly or indirectly, the power to
direct or cause the direction of the management and policies of the corporation
or other entity or the power to elect or appoint more than fifty percent (50%)
of the members of the governing body of the corporation or other entity.

<Page>

     1.2.   "BEHRING" shall mean Behringwerke Aktiengesellschaft, a subsidiary
of Hoechst Marion Roussel.

     1.3.   "BLA" shall mean a Biologics License Application filed with the FDA
after completion of human clinical trials to obtain marketing approval for a
Collaboration Product.

     1.4.   "CENTEON" shall mean Centeon L.L.C., a joint venture between Armour
Pharmaceutical Company, a subsidiary of Rhone-Poulenc Rorer, Inc., and Behring.

     1.5.   "COLLABORATION PRODUCT" shall mean any product comprising tgATIII
together with any process developed for use in the Field by a Party utilizing,
based upon or arising out of the Genzyme Patent Rights, the GTC Patent Rights,
the GTC Licensed ATIII Patent Rights, the Genzyme/GTC Patent Rights, the Genzyme
Technology, the GTC Technology, the Genzyme/GTC Technology or the Manufacturing
Know-How owned or controlled by any Party, including without limitation any and
all improvements, combination products, delivery systems and dosage forms
related thereto.

     1.6.   "COMMERCIALIZATION COSTS" with respect to a Collaboration Product
shall mean the variable costs and fixed costs incurred by ATIII LLC with respect
to work performed by the Parties and their Affiliates and subcontractors in
connection with the performance of the Commercialization Plan for such
Collaboration Product, including without limitation (a) GTC's Fully Absorbed
Cost of Goods for batches of Collaboration Product manufactured and supplied by
GTC in bulk form for use in connection with the performance of the
Commercialization Plan, (b) Genzyme's Fully Absorbed Costs of Goods incurred in
connection with the production of Collaboration Products in finished form,
including without limitation the performance of assay and purification work, for
use in connection with the performance of the Commercialization Plan and (c)
sales and marketing costs related to performing market research, advertising,
producing promotional literature, sponsoring seminars and symposia, originating
sales and providing reimbursement and other patient support services. For
purposes of this Section 1.6, "VARIABLE COSTS" shall be deemed to be the cost of
labor, raw materials, supplies and other resources directly consumed in the
conduct of the Commercialization Plan and manufacture of Collaboration Product
for use in commercialization activities, as well as royalties payable to Third
Parties. For purposes of Section 1.6, "FIXED COSTS" shall be deemed to be the
cost of facilities, utilities, insurance, equipment depreciation and other fixed
costs directly related to the conduct of the Commercialization Plan and the
manufacture of Collaboration Product for use in commercialization activities,
allocated based upon the proportion of such costs directly attributable to
support of the Commercialization Plan and the manufacture of Collaboration
Product for use in commercialization activities or by such other method of cost
allocation as may be approved by the Steering Committee. All cost determinations
made hereunder shall be made in accordance with GAAP.

     1.7.   "COMMERCIALIZATION PLAN" shall mean the comprehensive plan for the
commercialization of a Collaboration Product, as more specifically described in
Section 6.1.1 hereof.

     1.8.   "DATE OF EXECUTION" shall mean the last date on which the Parties
executed this Agreement, as shown on the signature pages hereto.

                                        2
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     1.9.   "DEVELOPMENT COSTS" with respect to a Collaboration Product shall
mean the variable costs and fixed costs incurred by ATIII LLC with respect to
work performed by the Parties and their Affiliates and subcontractors in
connection with the conduct of the Development Plan for such Collaboration
Product, including without limitation (a) direct, out-of-pocket external costs,
including clinical grants, clinical laboratory fees, positive controls and the
cost of studies conducted and services provided by contract research
organizations and individuals, consultants, toxicology contractors, and
manufacturers necessary or useful for the purpose of obtaining Regulatory
Approvals for such Collaboration Product, (b) amounts paid to Genzyme and GTC by
ATIII LLC with respect to research and development and pre-commercialization
sales and marketing efforts as set forth in the Development Plan for such
Collaboration Product, including without limitation the efforts of Genzyme and
GTC to develop a process for the manufacture of such Collaboration Product and
the Fully Absorbed Cost of Goods for batches of such Collaboration Product
manufactured and supplied for use in preclinical and clinical trials and
pre-commercialization activities, (c) costs related to data management,
statistical designs and studies, document preparation and other expenses
associated with the clinical testing program for such Collaboration Product and
(d) costs for preparing, submitting, reviewing or developing data or information
for the purpose of submission of applications to obtain Regulatory Approvals for
such Collaboration Product. For purposes of this Section 1.9, "VARIABLE COSTS"
shall be deemed to be the cost of labor, raw materials, supplies and other
resources directly consumed in the conduct of the Development Program and the
manufacture of the Collaboration Product for use in preclinical and clinical
trials and pre-commercialization activities. For purposes of this Section 1.9,
"FIXED COSTS" shall be deemed to be the cost of facilities, utilities,
insurance, facility and equipment depreciation and other fixed costs directly
related to the conduct of the Development Program and the manufacture of the
Collaboration Product for use in preclinical and clinical trials and
pre-commercialization activities, allocated based upon the proportion of such
costs directly attributable to support of the Development Program and the
manufacture of the Collaboration Product for use in preclinical and clinical
trials and pre-commercialization activities or by such other method of cost
allocation as may be approved by the Steering Committee. All cost determinations
made hereunder shall be made in accordance with GAAP.

     1.10.  "DEVELOPMENT PLAN" shall mean the comprehensive plan and budget for
the development of a Collaboration Product under the Development Program, as
more specifically described in Section 5.1.2 hereof.

     1.11.  "DEVELOPMENT PROGRAM" shall mean the preclinical and clinical
development of Collaboration Products, including the preparation and filing of
all applications for Regulatory Approvals for each Collaboration Product.

     1.12.  "DISTRIBUTION MARGIN" with respect to Net Sales of a Collaboration
Product shall mean the amount of the Distributor's Discount PLUS the amount by
which Genzyme's actual selling price exceeds the Estimated Net Selling Price for
such Collaboration Product OR, if Genzyme's actual selling price is less than
the Estimated Net Selling Price for such Collaboration Product, MINUS the amount
of such difference. For purposes of this Section 1.12, "GENZYME'S ACTUAL SELLING
PRICE" shall mean Genzyme's gross invoiced sales price billed to customers
reduced to reflect any amounts incurred resulting from any rebates, chargebacks
or refunds subsequently allowed and taken.

                                        3
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     1.13.  "DISTRIBUTOR'S DISCOUNT" shall mean the dollar amount per unit of
Collaboration Product fixed by the Steering Committee as a discount from the
Estimated Net Selling Price at which Genzyme purchases such Collaboration
Product from ATIII LLC.

     1.14.  "EFFECTIVE DATE" shall mean the January 1, 1998.

     1.15.  "ESTIMATED FULLY ABSORBED COST OF GOODS" with respect to a
Collaboration Product shall mean GTC's Fully Absorbed Cost of Goods estimated by
the Steering Committee for quantities of Collaboration Product to be purchased
by ATIII LLC pursuant to Article 7 hereof. The Estimated Fully Absorbed Cost of
Goods for a Collaboration Product shall be set forth in the Development Plan and
Commercialization Plan for such Collaboration Product. The Steering Committee
may adjust the Estimated Fully Absorbed Cost of Goods for a Collaboration
Product to the extent necessary or appropriate to reflect changes in market
conditions and actual manufacturing experience.

     1.16.  "ESTIMATED NET SELLING PRICE" with respect to a Collaboration
Product shall mean the price estimated by the Steering Committee at which such
Collaboration Product will be sold by Genzyme to Third Party customers
purchasing such Collaboration Product for resale. The Estimated Net Selling
Price shall be set forth in the Commercialization Plan for such Collaboration
Product. The Steering Committee may adjust the Estimated Net Selling Price for a
Collaboration Product to the extent necessary or appropriate to reflect changes
in market conditions and actual sales experience.

     1.17.  "FIELD" shall mean any and all indications for ATIII, including
without limitation diagnosis, treatment or prevention of hereditary and acquired
ATIII deficiencies.

     1.18.  "FDA" shall mean the United States Food and Drug Administration, any
successor agency, or the regulatory authority of any country other than the
United States with responsibilities comparable to those of the United States
Food and Drug Administration.

     1.19.  "FULLY ABSORBED COST OF GOODS" with respect to a Collaboration
Product shall mean (a) the variable costs and fixed costs incurred by a Party
associated with the manufacture (inclusive of finishing processes) of batches of
such Collaboration Product or (b) if such Collaboration Product is not
manufactured by the Parties, the transfer price for batches of such
Collaboration Product purchased from Third Party manufacturers. For purposes of
this Section 1.19, "VARIABLE COSTS" shall be deemed to be the cost of labor, raw
materials, supplies and other resources directly consumed in the manufacture of
batches of such Collaboration Product. For purposes of this Section 1.19, "FIXED
COSTS" shall be deemed to be the cost of facilities, utilities, insurance,
facility and equipment depreciation and other fixed costs directly related to
the manufacture of batches of such Collaboration Product. Fixed costs shall be
allocated to such Collaboration Product based upon the proportion of such costs
directly attributable to support of the manufacturing process for such
Collaboration Product. If a facility is used to manufacture Collaboration
Products and products for other programs of either Genzyme or GTC (including
without limitation products for use or sale in the SMIG Territory), fixed costs
shall be allocated in proportion to the use of such facility for the manufacture
of Collaboration Products and products for such other programs. Fully Absorbed
Cost of Goods shall exclude all costs otherwise reimbursed pursuant to this
Agreement. In the event that either GTC or Genzyme

                                        4
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subcontracts with the other Party to perform any work on its behalf in
connection with the manufacturing responsibilities assigned to GTC or Genzyme,
respectively, pursuant to Section 7.2.1 hereof, GTC and Genzyme (i) shall each
directly charge ATIII LLC their respective Fully Absorbed Cost of Goods and (ii)
shall not include any part of the other Party's Fully Absorbed Cost of Goods in
the amount so charged to ATIII LLC. Except as otherwise provided in this
Agreement, all cost determinations made hereunder shall be made in accordance
with GAAP.

     1.20.  "GAAP" shall mean United States generally accepted accounting
principles, consistently applied, except when different accounting principles
are required under the terms of the Operating Agreement, in which case the
accounting principles mandated under the Operating Agreement shall control.

     1.21.  "GENZYME PATENT RIGHTS" shall mean all present Patent Rights owned
or controlled by, or licensed (with the right to sublicense where possible) to,
Genzyme, to the extent that such Patent Rights cover a compound, composition,
biological or other material, product-by-process, method, apparatus,
manufacturing or other process, relating to or useful for the research,
development, manufacture or commercialization of Collaboration Products for use
in the Field, including the Genzyme Patent Rights listed in SCHEDULE 1.21
hereto.

     1.22.  "GENZYME TECHNOLOGY" shall mean Technology owned or controlled by,
or licensed (with the right to sublicense) to, Genzyme relating to or useful for
the research, development, manufacture or commercialization of Collaboration
Products for use in the Field.

     1.23.  "GENZYME/GTC PATENT RIGHTS" shall mean the Patent Rights that claim
Joint Inventions (as such term is defined in Section 9.1.1 hereof) that are
jointly discovered, made or conceived during and in connection with the Program
to the extent that such Patent Rights cover a compound, composition, biological
or other material, product-by-process, method, apparatus, manufacturing or other
process, or transgenic technology relating to or useful for the research,
development, manufacture or commercialization of Collaboration Products for use
in the Field.

     1.24.  "GENZYME/GTC TECHNOLOGY" shall mean all Technology discovered, made
or conceived during and in connection with the Program, and future Technology
owned or controlled by, or licensed (with the right to sublicense where
possible) to, either Genzyme or GTC relating to or useful for the research,
development, manufacture or commercialization of Collaboration Products for use
in the Field.

     1.25.  "GTC LICENSED ATIII PATENT RIGHTS" shall mean all present and future
Patent Rights in the Territory sublicensed (whether exclusively or
nonexclusively) by GTC from Behring pursuant to the Agreement dated September
29, 1990 by and between Behring, SMIG and GTC (as the successor to Genzyme's
interest therein) (the "ORIGINAL ATIII AGREEMENT"). SCHEDULE 1.25 hereto lists
the GTC Licensed ATIII Patent Rights as of the Date of Execution.

     1.26.  "GTC PATENT RIGHTS" shall mean, except as to GTC Licensed ATIII
Patent Rights, all present Patent Rights owned or controlled by, or licensed
(with the right to sublicense where possible) to, GTC, to the extent that such
Patent Rights cover a compound, composition, biological or other material,
product-by-process, method, apparatus, manufacturing or other

                                        5
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process, or transgenic production technology relating to or useful for the
research, development, manufacture or commercialization of Collaboration
Products for use in the Field, including the GTC Patent Rights listed in
SCHEDULE 1.26 hereto.

     1.27.  "GTC TECHNOLOGY" shall mean all present Technology owned or
controlled by, or licensed (with the right to sublicense where possible) to, GTC
relating to or useful for the research, development, manufacture or
commercialization of Collaboration Products for use in the Field.

     1.28.  "MAJOR MARKET COUNTRIES" shall mean the United States, the United
Kingdom, Austria, Germany, Italy and The Czech Republic. The Steering Committee
may from time to time designate additional countries as Major Market Countries
or remove countries from the list of designated Major Market Countries with
respect to a Collaboration Product to the extent necessary to reflect changes in
market conditions. Any such additions or deletions shall be set forth in the
Commercialization Plan for such Collaboration Product.

     1.29.  "MANUFACTURER'S PROFIT" shall mean the dollar amount in excess of
GTC's Estimated Fully Absorbed Costs of Goods Sold included in the price at
which ATIII LLC purchases quantities of Collaboration Products in bulk form from
GTC. The Manufacturer's Profit shall only be payable in connection with the
purchase of Collaboration Products ultimately intended for commercial sale.

     1.30.  "MANUFACTURING KNOW-HOW" shall mean all information, techniques,
inventions, discoveries, improvements, practices, methods, knowledge, skill,
experience and other technology, whether or not patentable or copyrightable, and
any patent applications, patents or copyrights based thereon, relating to or
necessary or useful for the production, purification, packaging, storage and
transportation of Collaboration Products, including without limitation
specifications, acceptance criteria, manufacturing batch records, standard
operating procedures, engineering plans, installation, operation and process
qualification protocols for equipment, validation records, master files
submitted to the FDA, process validation reports, environmental monitoring
processes, test data including pharmacological, toxicological and clinical test
data, cost data and employee training materials.

     1.31.  "MANUFACTURING MARGIN" shall mean the price at which ATIII LLC
purchases quantities of a Collaboration Product in bulk form from GTC LESS GTC's
actual Fully Absorbed Cost of Goods for such quantities.

     1.32.  "MEMBER" shall have the meaning set forth in the Operating
Agreement.

     1.33.  "NET PROFIT" of ATIII LLC for any period shall be equal to (a) the
sum during such period of all revenues recognized and recorded by ATIII LLC
during such period, including without limitation (i) revenues from Net Sales of
all Collaboration Products sold directly by ATIII LLC and (ii) all revenues
received by ATIII LLC from Third Parties as consideration for sublicensing the
manufacture, use, distribution or sale of Collaboration Products, LESS (b) all
expenses incurred by ATIII LLC during such period, including without limitation
expenses incurred in respect of Development Costs, New Facility Costs and
Commercialization Costs and

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facility and equipment depreciation costs. All determinations made hereunder
shall be made in accordance with GAAP.

     1.34.  "NET SALES" with respect to a Collaboration Product shall mean the
gross invoiced sales price of such Collaboration Product billed to (a)
independent Third Party customers, including without limitation distributors, in
BONA FIDE arms-length transactions and (b) Genzyme and its Affiliates, LESS, for
purposes only of calculating the payments set forth in Article 13 hereof, to the
extent such amounts are included in the gross invoiced sales price, actual: (i)
freight and insurance costs incurred in transporting such Collaboration Product
to such customers; (ii) quantity, cash and other trade discounts actually
allowed and taken; (iii) customs duties, surcharges and taxes and other
governmental charges incurred in connection with the exportation or importation
of such Collaboration Product in final form; (iv) bad debt expense; (v) amounts
repaid or credited by reason of rejections (due to Collaboration Product
spoilage, damage, expiration of useful life or otherwise) or retroactive price
reductions; (vi) amounts incurred resulting from governmental mandated rebate or
discount programs; and (vii) Third Party rebates and chargebacks actually
allowed and taken, including without limitation hospital buying group
chargebacks, hospital buying group/group purchasing organization administration
fees or managed care organization rebates. The Steering Committee shall
determine how any transfers of Collaboration Products by ATIII LLC to Genzyme or
its Affiliates for use as samples shall be treated for purposes of this Section
1.34, and ATIII LLC shall make such transfers in accordance with such
determination. The amount of Net Sales for any period shall be determined on the
basis of sales recorded in such period in accordance with GAAP.

     1.35.  "NEW FACILITY" shall mean any new manufacturing facility (or portion
thereof) to be constructed after the Date of Execution to be used to manufacture
(inclusive of finishing processes) Collaboration Products.

     1.36.  "NEW FACILITY COSTS" shall mean the variable costs and fixed costs
incurred by ATIII LLC with respect to (a) the design, construction, validation
and operation of the New Facility, including without limitation (i) costs for
preparing, submitting, reviewing or developing data or information for the
purpose of submission of applications to obtain Regulatory Approval for the New
Facility and (ii) the scale-up of the manufacturing process (inclusive of
finishing processes) for Collaboration Products to be manufactured in the New
Facility, and (b) the manufacture of Collaboration Products in the New Facility.
For purposes of this Section 1.36, "VARIABLE COSTS" shall be deemed to be the
cost of labor, raw materials, supplies and other resources directly consumed in
the design, construction, validation and operation of the New Facility and in
the manufacture of Collaboration Products in the New Facility. For purposes of
this Section 1.36, "FIXED COSTS" shall be deemed to be the cost of facilities,
utilities, insurance, equipment depreciation and other fixed costs related to
the operation of the New Facility and the manufacture of Collaboration Products
in the New Facility. If the New Facility is used to manufacture Collaboration
Products and products for other programs of either Genzyme or GTC (including
without limitation products for use or sale in the SMIG Territory), variable
costs and fixed costs shall be allocated in proportion to the use of the New
Facility for the manufacture of Collaboration Products and products for such
other programs. New Facility Costs shall exclude all costs otherwise reimbursed
pursuant to this Agreement. Except as otherwise provided in this Agreement, all
cost determinations made hereunder shall be made in accordance with GAAP.

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     1.37.  "OPERATING AGREEMENT" shall mean the Amended and Restated Operating
Agreement of ATIII LLC of even date herewith by and between GTC and Genzyme.

     1.38.  "PATENT RIGHTS" shall mean patents, patent applications,
certificates of invention, or applications for certificates of invention,
together with any extensions, registrations, confirmations, reissues, divisions,
continuations or continuations-in-part, re-examinations or renewals thereof.

     1.39.  "PERCENTAGE INTEREST" shall have the meaning set forth in the
Operating Agreement.

     1.40.  "PROGRAM" shall mean the collaboration among ATIII LLC, GTC and
Genzyme described in this Agreement.

     1.41.  "PROGRAM COSTS" shall mean all Program-related costs, including
without limitation Development Costs, New Facility Costs and Commercialization
Costs, in each case as such costs are incurred or accrued by ATIII LLC on or
after the Effective Date.

     1.42.  "PROGRAM MANAGEMENT TEAM" shall mean the joint team composed of
representatives of Genzyme and GTC described in Section 8.1.1 hereof.

     1.43.  "PURCHASE AGREEMENT" shall mean the Purchase Agreement of even date
herewith by and between GTC and Genzyme.

     1.44.  "REGULATORY APPROVALS" shall mean all approvals from regulatory
authorities in any country required lawfully to market Collaboration Products in
any such country, including without limitation any BLA, any establishment
license application filed with the FDA to obtain approval of the facilities and
equipment to be used to manufacture a Collaboration Product, and any product
pricing approvals where applicable.

     1.45.  "REGULATORY SCHEME" shall mean the United States Public Health
Service Act and the regulations, interpretations and guidelines promulgated
thereunder by the FDA or the regulatory scheme applicable to the Collaboration
Products in any country other than the United States, as such statutes,
regulations, interpretations and guidelines or regulatory schemes may be amended
from time to time.

     1.46.  "SMIG" shall mean SMI Genzyme Limited, a Japanese corporation and a
joint venture between Genzyme and Sumitomo Metal Industries, Ltd.

     1.47.  "SMIG TERRITORY" shall mean the territory in which SMIG has an
exclusive right and license with respect to ATIII pursuant to that certain
Research and Development Agreement dated September 11, 1990 by and between SMIG
and GTC (as the successor to Genzyme), as amended by that certain Amendment
Agreement dated March 15, 1994 by and between SMIG and GTC and that certain
letter agreement dated August 4, 1994 and that certain Agreement dated as of
January 31, 1997 (as amended, the "SMIG RESEARCH AGREEMENT"), which territory
consists of: Japan, China, Taiwan, Thailand, India, Sri Lanka, Indonesia,
Philippines, Vietnam, Singapore, Malaysia, Hong Kong, Myanmar (Burma), Pakistan,
Bangladesh, South Korea, Laos, Cambodia and their respective succession states.

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     1.48.  "SPECIFICATIONS" with respect to a Collaboration Product shall mean
the written specifications for such Collaboration Product determined by the
Program Management Team and approved by the Steering Committee; PROVIDED that
such specifications shall at all times comply with the relevant Regulatory
Scheme in the country of sale and in the country of use. The Specifications may
be amended from time to time by the Program Management Team provided that such
amendments are approved by the Steering Committee or the written agreement of
the Parties, as the case may be. Copies of such Specifications shall be
maintained by both GTC and Genzyme and shall become a part of this Agreement as
if incorporated herein.

     1.49.  "STEERING COMMITTEE" shall mean the governing body of ATIII LLC
composed of representatives of GTC and Genzyme appointed as described in Section
8.2.1 hereof.

     1.50.  "TECHNOLOGY" shall mean inventions, trade secrets, copyrights,
know-how, data and other intellectual property of any kind (including without
limitation any proprietary biological or other materials, compounds or reagents,
and transgenic production technology but not including Patent Rights).

     1.51.  "TERRITORY" shall mean the world excluding the SMIG Territory.

     1.52.  "THIRD PARTY" shall mean any entity other than ATIII LLC, GTC or
Genzyme and their respective Affiliates.

     1.53.  "TRANSGENIC ANIMAL" shall mean a non-human animal, or an egg, sperm
or embryo of such animal, which bears in its germline a foreign gene derived
from another animal species.

     1.54.  "TRANSGENIC ATIII", which may be abbreviated as "TGATIII", shall
mean recombinant human ATIII produced by expression of a recombinant ATIII gene
or ATIII cDNA or combination thereof in the milk of a Transgenic Animal bearing
such gene, cDNA or combination in its genome.

               ARTICLE 2. SCOPE AND STRUCTURE OF THE COLLABORATION

     2.1.   GENERAL. GTC and Genzyme formed ATIII LLC as the vehicle for a joint
venture between GTC and Genzyme to develop and commercialize Collaboration
Products in and throughout the Territory. GTC and Genzyme are the sole initial
members of ATIII LLC and own ninety-six and three-tenths percent (96.3%) and
three and seven-tenths percent (3.7%) interests in ATIII LLC, respectively. In
accordance with the terms of the Purchase Agreement to be executed immediately
hereafter, GTC will sell and assign to Genzyme a forty-six and three-tenths
percent (46.3%) interest in ATIII LLC and consequently GTC and Genzyme will each
own a fifty percent (50%) interest in ATIII LLC (subject to adjustment pursuant
to Section 4.1.4 hereof and pursuant to the Operating Agreement). ATIII LLC will
undertake the Development Program for each Collaboration Product, with each of
the Parties assuming responsibility for those portions of the Development
Program allocated to it under this Agreement. Upon completion of the Development
Program, GTC will manufacture bulk quantities of the Collaboration Products on
behalf of ATIII LLC, Genzyme will provide finishing processing of the
Collaboration Products for commercial sale on behalf of ATIII LLC and Genzyme
will market and sell the Collaboration Products in the Territory as exclusive
distributor for ATIII

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LLC (except with respect to rights held by Centeon), all on the terms and
conditions set forth in this Agreement or such other terms and conditions as the
Parties may agree upon.

     2.2.   EXCLUSIVE RELATIONSHIP. During the term of this Agreement, neither
ATIII LLC, Genzyme nor GTC, nor any of their Affiliates shall independently, or
with a Third Party, conduct research or development activities regarding, or
engage in the manufacture, marketing, sale or distribution of, products
comprising tgATIII in the Field and in the Territory other than as part of the
Program; PROVIDED, HOWEVER, that ATIII LLC may conduct such activities with
Centeon pursuant to the Original ATIII Agreement or pursuant to any amendment
thereto or any other agreement that may be entered into with Centeon approved by
the Steering Committee pursuant to Section 2.3 below. In addition, during the
two-year period following termination of this Agreement, neither (a) the
breaching Party and its Affiliates in the case of termination pursuant to
Section 13.2.1 hereof, (b) Genzyme or its Affiliates in the case of termination
pursuant to Section 13.2.2 hereof, (c) the terminating Party and its Affiliates
in the case of termination pursuant to Section 13.2.3 hereof or (d) the
non-terminating Party and its Affiliates in the case of termination pursuant to
Section 13.2.4 hereof shall independently, or with a Third Party, conduct
research regarding, or engage in the manufacture, marketing, sale or
distribution of, products comprising tgATIII in the Field and in the Territory;
PROVIDED, HOWEVER, that in the event that this Agreement is terminated pursuant
to Section 13.2.3 hereof and the non-terminating Party does not exercise its
option under Section 13.3.3 hereof, then the restrictions set forth in this
sentence shall not apply. Notwithstanding the foregoing, nothing herein is
intended to restrict GTC or Genzyme or their respective Affiliates from
conducting research or development activities regarding, or engaging in the
manufacture, marketing, sale or distribution of, products that have
substantially different biomedical pathways and are targeted to the same
indications included hereunder.

     2.3.   CENTEON AGREEMENT. In 1990, Genzyme, SMIG and Behring entered into
the Original ATIII Agreement under which Genzyme and SMIG acquired sublicense
rights from Behring for certain patents and patent applications related to
recombinant human ATIII. Pursuant to a Technology Transfer Agreement dated May
11, 1993, Genzyme transferred to GTC its right to manufacture, market and sell
tgATIII under the Original ATIII Agreement. GTC hereby assigns to ATIII LLC all
of its right, title and interest in the Territory under the Original ATIII
Agreement. As soon as practicable after the Date of Execution, Genzyme and GTC
together, on behalf and in the name of ATIII LLC, shall use their respective
commercially reasonable and diligent efforts (as such term is defined in Section
5.1.1 hereof) to obtain a written agreement with Centeon, as the successor to
Behring's interest in the Original ATIII Agreement, clarifying the rights and
obligations of Centeon and ATIII LLC under the Original ATIII Agreement,
including without limitation Centeon's consent (or lack thereof) to the grant of
sublicense rights to the GTC Licensed ATIII Patent Rights by GTC to ATIII LLC
pursuant to Section 3.1.1 hereof and the further grant of sublicense rights by
ATIII LLC to Genzyme pursuant to Section 3.2 hereof. Any agreement with Centeon
relating to the Original ATIII Agreement or the subject matter thereof must be
approved in advance by the Steering Committee. In the event that:

                    (a)  (i) Centeon and ATIII LLC reach an agreement concerning
their rights and obligations under the Original ATIII Agreement and as a result
Genzyme's rights to market and sell Collaboration Products hereunder are
terminated or (ii) Centeon and ATIII LLC are unable to reach a mutually
acceptable agreement and Centeon successfully brings an action

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against ATIII LLC to enforce the terms of the Original ATIII Agreement, then all
amounts received by ATIII LLC from Centeon (other than payments with respect to
sales of Collaboration Products by ATIII LLC to Centeon) shall be promptly
distributed upon receipt to the Members in such a manner as to reimburse the
Members for amounts paid by such Member to cover Development Costs (including
all amounts paid by Genzyme pursuant to Section 1.10 of the Convertible Debt and
Development Funding Agreement dated as of March 29, 1996 by and between Genzyme
and GTC (the "CONVERTIBLE DEBT AGREEMENT")) in the reverse chronological order
in which such costs were incurred (i.e., with the costs incurred most recently
being reimbursed first); or

                    (b)  Centeon and ATIII LLC reach an agreement concerning
their rights and obligations under the Original ATIII Agreement and Genzyme's
rights to market and sell Collaboration Products hereunder are not terminated,
then all amounts received by ATIII LLC from Centeon (other than payments with
respect to sales of Collaboration Products by ATIII LLC to Centeon) (i) shall be
retained by ATIII LLC to the extent necessary to fund future Development Costs,
with the funding obligations of Genzyme and GTC with respect to such costs being
reduced by such amounts in proportion to their respective funding obligations
under Section 4.1 hereof and (ii) the balance, if any, shall be distributed to
the Members in such a manner as to reimburse the Members for amounts paid by
such Member to cover Development Costs (including all amounts paid by Genzyme
pursuant to its funding obligation under Section 1.10 of the Convertible Debt
Agreement) in the reverse chronological order in which such costs were incurred
(i.e., with the costs incurred most recently being reimbursed first).

     2.4.   SMIG AGREEMENT. Genzyme and ATIII LLC each hereby acknowledge that
SMIG has exclusive rights to use, manufacture and sell tgATIII and products
comprising tgATIII in the SMIG Territory pursuant to the SMIG Research
Agreement. The Parties hereby agree that if any equipment, manufacturing process
and/or facility owned or leased by ATIII LLC is used for the manufacture of
products for use or sale by SMIG, (i) GTC and/or SMIG shall be solely
responsible for the costs of the manufacturing of such products, (ii) at all
times the manufacture of Collaboration Products in accordance with Article 7
hereof shall be given priority with respect to the use of such property and
(iii) ATIII LLC shall be entitled to receive commercially reasonable
compensation for such use from GTC and/or SMIG.

     The Parties acknowledge that, pursuant to Section 8.1 of the SMIG Research
Agreement, GTC will be entitled to receive and retain for its own account
milestone payments and royalty payments from SMIG with respect to sales of
tgATIII, products comprising tgATIII and Transgenic Animals and that pursuant to
Section 9.1 of the SMIG Research Agreement, SMIG will be entitled to receive
royalty payments with respect to sales of tgATIII, products comprising tgATIII
and Transgenic Animals a female of which secretes ATIII in its milk in North and
South America and in the Non Exclusive Territory (as defined in the SMIG
Research Agreement). The Parties hereby agree that such royalties payable to
SMIG shall be paid as follows: (a) first, by GTC up to an aggregate amount equal
to the sum of (i) all royalty payments paid by SMIG to GTC after the Date of
Execution relating to tgATIII, products comprising tgATIII and Transgenic
Animals, and GTC will not charge ATIII LLC for such royalty payments to SMIG,
and (ii) all milestone payments for milestone events that have not been achieved
as of the Date of Execution paid by SMIG to GTC after the Date of Execution
relating to tgATIII, products comprising tgATIII and Transgenic Animals, and GTC
will not charge ATIII LLC for such

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royalty payments to SMIG, and (b) after depletion of the funds described in
clause (a) hereof, by GTC subject to reimbursement by ATIII LLC after receipt by
ATIII LLC of an invoice therefor from GTC. GTC shall deliver to Genzyme
quarterly reports setting forth (i) the aggregate amount of all royalty and
milestone payments received by GTC from SMIG after the Date of Execution
relating to tgATIII, products comprising tgATIII and Transgenic Animals
(excluding milestone payments for milestone events achieved prior to the Date of
Execution), (ii) the aggregate amount of all royalty payments paid by GTC to
SMIG pursuant to Section 9.1 of the SMIG Research Agreement relating to sales of
tgATIII, products comprising tgATIII and Transgenic Animals a female of which
secretes ATIII in its milk in North and South American and the Non Exclusive
Territory and (iii) the remaining amount of the funds described in clause (i) of
this sentence. The Parties acknowledge that the amount of milestone payments for
milestone events achieved in all material and all substantive respects by GTC
and billed by GTC to SMIG prior to the Date of Execution shall not be included
in clause (a)(ii) above even if such payment has not been received by GTC from
SMIG as of the Date of Execution. Such reports shall be subject to Genzyme's
audit rights set forth in Section 4.5 hereof. GTC shall not enter into any
amendment or modification of the SMIG Research Agreement relating to tgATIII,
products comprising tgATIII and Transgenic Animals without the prior written
consent of the Steering Committee after the Date of Execution.

                  ARTICLE 3. GRANTS AND RESERVATIONS OF RIGHTS

     3.1.   LICENSES OF RIGHTS TO ATIII LLC.

            3.1.1   GRANTS FROM GTC.

                    (a)  EXCLUSIVE GRANT. Except as otherwise expressly provided
herein, GTC hereby grants to ATIII LLC an exclusive, irrevocable (during the
term of this Agreement), royalty-free right and sublicense, with the right to
grant further sublicenses, under the GTC Licensed ATIII Patent Rights (subject
to Section 2.3 above), the Genzyme/GTC Patent Rights and the Genzyme/GTC
Technology and any associated Technology and Manufacturing Know- How owned or
controlled by GTC to develop, make, have made, use, offer for sale, sell, have
sold, import and export Collaboration Products for use in the Field and in the
Territory.

                    (b)  NON-EXCLUSIVE GRANT. Except as otherwise expressly
provided herein, GTC hereby grants to ATIII LLC a non-exclusive, irrevocable
(during the term of this Agreement), royalty-free right and license, with the
right to grant sublicenses, under the GTC Patent Rights and GTC Technology to
develop, make, have made, use, offer for sale, sell, have sold, import and
export Collaboration Products for use in the Field and in the Territory.

            3.1.2   GRANTS FROM GENZYME.

                    (a)  EXCLUSIVE GRANT. Except as otherwise expressly provided
herein, Genzyme hereby grants to ATIII LLC an exclusive, irrevocable (during the
term of this Agreement), royalty-free right and sublicense, with the right to
grant further sublicenses, under the Genzyme/GTC Patent Rights and the
Genzyme/GTC Technology and any associated Technology and Manufacturing Know-How
owned or controlled by Genzyme to develop, make,

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have made, use, offer for sale, sell, have sold, import and export Collaboration
Products for use in the Field and in the Territory.

                    (b)  NON-EXCLUSIVE GRANT. Except as otherwise expressly
provided herein, Genzyme hereby grants to ATIII LLC a non-exclusive, irrevocable
(during the term of this Agreement), royalty-free right and license, with the
right to grant sublicenses, under the Genzyme Patent Rights, Genzyme Technology
and the Manufacturing Know-How owned or controlled by Genzyme, to develop, make,
have made, use, offer for sale, sell, have sold, import and export Collaboration
Products for use in the Field and in the Territory.

            3.1.3   ATIII LLC UNDERTAKINGS; SUBLICENSES. In consideration of the
licenses granted under this Section 3.1, ATIII LLC hereby undertakes to pay all
royalties, sublicense fees and other costs or expenses payable to Third Parties
associated with the acquisition or use of such licenses by ATIII LLC. SCHEDULE
3.1.3 hereto lists all of such obligations as of the Date of Execution. Except
as provided in Section 3.2 below, all sublicenses granted by ATIII LLC shall be
subject to prior approval by the Steering Committee. The Parties hereby
acknowledge that ATIII LLC may be required to grant a sublicense to Centeon in
connection with any agreement that may be negotiated with Centeon pursuant to
Section 2.3 hereof.

            3.1.4   RIGHTS OF ATIII LLC TO PATENT RIGHTS OR TECHNOLOGY DEVELOPED
OUTSIDE THE PROGRAM. In the event that either GTC or Genzyme develops, acquires
or otherwise comes to own or control or receives a license with respect to
Patent Rights, Technology or Manufacturing Know-How after the Date of Execution
other than in connection with the Program and such Patent Rights, Technology or
Manufacturing Know-How are useful in the Field and licensable by GTC or Genzyme,
as the case may be, the Party owning or controlling such Patent Rights,
Technology or Manufacturing Know-How shall grant to ATIII LLC an option
exercisable at the discretion of the Steering Committee to obtain an exclusive,
irrevocable (during the term of this Agreement) right and license, with the
right to grant sublicenses, to such Patent Rights, Technology or Manufacturing
Know-How limited to use in the Field and in the Territory to the extent
necessary or appropriate to enable ATIII LLC to develop, make, have made, use,
offer for sale, sell, have sold, import and export Collaboration Products, in
each case subject only to ATIII LLC's undertaking to pay (a) a commercially
reasonable portion of all costs incurred by GTC or Genzyme, as the case may be,
to acquire or develop such Patent Rights, Technology or Manufacturing Know-How,
(b) a commercially reasonable portion of any and all development costs incurred
by GTC or Genzyme, as the case may be, since the date such Party acquired or
developed such Patent Rights, Technology or Manufacturing Know-How and (c) all
royalties, sublicense fees and other costs or expenses payable to Third Parties
associated with the acquisition or use of such license by ATIII LLC; PROVIDED,
HOWEVER, that if GTC or Genzyme, as the case may be, does not own or have
exclusive rights to such Patent Rights, Technology or Manufacturing Know-How,
the license subject to ATIII LLC's option hereunder shall be for the same level
of exclusivity as the rights held by GTC or Genzyme, as the case may be, with
respect to such Patent Rights, Technology or Manufacturing Know-How.

     3.2.   SUBLICENSES OF RIGHTS FROM ATIII LLC TO GTC AND GENZYME. ATIII LLC
hereby grants to each of GTC and Genzyme a non-exclusive, irrevocable (during
the term of this Agreement), royalty-free right and sublicense under the Patent
Rights, Technology and Manufacturing Know-How licenses granted to it pursuant to
Section 3.1 solely to the extent

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required to permit such Party to perform its duties under this Agreement. ATIII
LLC also hereby grants Genzyme a non-exclusive, irrevocable (during the term of
this Agreement), royalty-free right and license to use any and all present and
future trademarks owned or licensed (with the right to sublicense) to ATIII LLC
in connection with the commercialization of Collaboration Products in the
Territory to the extent required to permit Genzyme to perform its duties under
this Agreement.

     3.3.   RESERVATION OF RIGHTS.

            3.3.1   RESERVATION BY GTC. Notwithstanding the license grants set
forth in Section 3.1, GTC at all times reserves the rights under the GTC Patent
Rights, the GTC Technology, the Genzyme/GTC Patent Rights, the Genzyme/GTC
Technology and the Manufacturing Know-How owned or controlled by GTC (a) to
make, have made and use Collaboration Products for research and development
purposes only, (b) to develop, make, have made, use, offer for sale, sell, have
sold, import and export (i) products outside the Field and/or outside the
Territory and (ii) products other than products comprising ATIII and (c) to
grant licenses to Third Parties for the foregoing purposes.

            3.3.2   RESERVATION BY GENZYME. Notwithstanding the license grants
set forth in Section 3.1, Genzyme at all times reserves the rights under the
Genzyme Patent Rights, the Genzyme Technology, the Genzyme/GTC Patent Rights,
the Genzyme/GTC Technology and Manufacturing Know-How owned or controlled by
Genzyme (a) to make, have made and use Collaboration Products for research and
development purposes only, (b) to develop, make, have made, use, offer for sale,
sell, have sold, import and export (i) products outside the Field and/or outside
the Territory and (ii) products other than products comprising ATIII and (c) to
grant licenses to Third Parties for the foregoing purposes.

                    ARTICLE 4. PROGRAM FUNDING; LLC INTEREST

     4.1.   PROGRAM FUNDING COMMITMENTS. Each of Genzyme and GTC hereby
undertakes to make capital contributions to ATIII LLC as follows:

            4.1.1   1998 FUNDING. For the 1998 calendar year, (a) Genzyme shall
make capital contributions to ATIII LLC sufficient to pay all Program Costs
other than New Facility Costs for 1998 until such time as (i) the aggregate
amount of the capital contributions paid by Genzyme for the 1997 and 1998
calendar years (including all amounts paid by Genzyme to GTC during 1997
pursuant to Section 1.10 of the Convertible Debt Agreement) equals (ii) seventy
percent (70%) of the total Program Costs other than New Facility Costs (incurred
and/or budgeted) for the 1997 and 1998 calendar years (including without
limitation all costs incurred by GTC and Genzyme in 1997 in connection with the
research, development and manufacture of tgATIII)(the "GENZYME 1997/1998
AMOUNT"), and (b) GTC shall make capital contributions to ATIII LLC sufficient
to pay all Program Costs other than New Facility Costs for 1998 after such time
as the Genzyme 1997/1998 Amount has been paid.

            4.1.2   FUNDING AFTER 1998. Beginning with the 1999 calendar year,
(a) Genzyme shall make capital contributions to ATIII LLC sufficient to pay (i)
seventy percent (70%) of all Program Costs other than New Facility Costs until
such time as the aggregate capital

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contributions paid by Genzyme pursuant to this Section 4.1 (including all
amounts paid by Genzyme to GTC during 1997 pursuant to Section 1.10 of the
Convertible Debt Agreement) equals thirty three million dollars ($33,000,000)
(the "GENZYME 70% FUNDING COMMITMENT") and (ii) fifty percent (50%) of all
Program Costs other than New Facility Costs thereafter and (b) GTC shall make
capital contributions to ATIII LLC sufficient to pay (i) thirty percent (30%) of
all Program Costs other than New Facility Costs until the Genzyme 70% Funding
Commitment has been satisfied and (ii) fifty percent (50%) of all Program Costs
other than New Facility Costs thereafter.

            4.1.3   NEW FACILITY COSTS. Genzyme and GTC shall each also make
capital contributions to ATIII LLC sufficient to pay fifty percent (50%) of all
New Facility Costs to be incurred on or after the Effective Date.

            4.1.4   ADJUSTMENT TO PERCENTAGE INTEREST AND FUNDING COMMITMENT. In
the event that either GTC or Genzyme fails to make a capital contribution
pursuant to this Section 4.1 and Section 4.2 below, and the other Party does not
elect to terminate this Agreement pursuant to Section 13.2.1 hereof, then the
Percentage Interests in ATIII LLC and the future funding responsibility of the
Members shall be adjusted as provided in Section 4.1(b) of the Operating
Agreement.

     4.2.   PROGRAM FUNDING CAPITAL CONTRIBUTIONS.

            4.2.1   INITIAL CAPITAL CONTRIBUTIONS. No later than January 5,
1998, GTC and Genzyme shall each make a capital contribution to ATIII LLC in an
amount equal to their respective capital contribution obligations pursuant to
Section 4.1.1 and 4.1.3 above with respect to Program Costs budgeted to be
incurred from the Effective Date through and including January 31, 1998.

            4.2.2   MONTHLY CAPITAL CONTRIBUTIONS. With respect to each calendar
month after December 1997, Genzyme and GTC shall each make capital contributions
to ATIII LLC, monthly in advance, not later than the fifteenth (15th) day of the
prior calendar month, in an aggregate amount equal to one-third of the Program
Costs budgeted to be incurred by ATIII LLC in any then-current Development Plan
or Commercialization Plan for the calendar quarter in which such calendar month
occurs, allocated between such Parties in accordance with the funding
responsibility assumed by Genzyme and GTC pursuant to Section 4.1 above. Upon
receipt of each such capital contribution from Genzyme or GTC, as the case may
be, ATIII LLC shall promptly pay the Parties that portion of the budgeted
Program Costs to which they are respectively entitled.

            4.2.3   QUARTERLY STATEMENTS; QUARTERLY RECONCILIATION. Within
twenty (20) days after the end of each of the first three (3) calendar quarters
of each year and within fifty (50) days after the end of each calendar year,
each of GTC and Genzyme shall provide ATIII LLC with a detailed itemization of
its Program Costs actually incurred during the previous quarter. Each of GTC and
Genzyme shall provide the other Party with estimates of such costs upon the
reasonable request of the other Party prior to the dates such statements are
due. Within thirty (30) days following receipt of the quarterly statement of
actual Program Costs provided by each of GTC and Genzyme, GTC and Genzyme shall
each make an additional capital contribution to

                                       15
<Page>

ATIII LLC in the amount of any actual Program Costs shown thereon and not yet
paid for which such Party has assumed funding responsibility pursuant to Section
4.1 above but only to the extent that such amount, together with all prior
capital contributions to date during such year, does not exceed one hundred five
percent (105%) of the total Program Costs budgeted year-to-date through the end
of the quarter to which such statement relates (except to the extent such excess
is approved by the Steering Committee pursuant to Section 5.1.3 hereof). If the
aggregate amount stated to be due from ATIII LLC in such quarterly statements
for actual Program Costs is less than the amount already contributed by the
Parties to the capital of ATIII LLC with respect to budgeted Program Costs for
such calendar quarter, such excess shall be credited pro rata against the next
successive monthly capital contribution due from Genzyme or GTC hereunder.

     4.3.   DISTRIBUTIONS. Distributions shall be made annually to each Member
in amounts determined in accordance with the Operating Agreement. Amounts
available for distribution shall be calculated for each calendar quarter after
the date of the first sale of a Collaboration Product following Regulatory
Approval of such Collaboration Product and shall be reported to each of GTC and
Genzyme within ninety (90) days following the end of each such quarter. All
distributions to the Parties will be accompanied by a report setting forth the
basis for such distribution. Such reports shall be subject to audit rights as
set forth in Section 4.5 below, MUTATIS MUTANDIS.

     4.4.   SALE AND PURCHASE OF LLC INTEREST. Immediately after the execution
of this Agreement and in accordance with the terms and conditions of the
Purchase Agreement, GTC shall sell, assign and transfer to Genzyme, and Genzyme
shall purchase from GTC, a forty-six and three-tenths percent (46.3%) interest
in ATIII LLC (subject to adjustment pursuant to Section 4.1.4 hereof and
pursuant to the Operating Agreement) for an aggregate amount of twelve million
five hundred thousand ten dollars ($12,500,010) payable as set forth below:

                    (a)  Genzyme shall pay to GTC an amount of ten dollars ($10)
upon execution of the Purchase Agreement;

                    (b)  Genzyme shall pay to GTC an amount of two million five
hundred thousand dollars ($2,500,000) after the second consecutive quarter in
which Net Sales of Collaboration Products for such quarter exceed five million
dollars ($5,000,000); and

                    (c)  Genzyme shall pay to GTC an amount of ten million
dollars ($10,000,000) on the first full approval by the FDA of a Major Market
Country or by the European Union's European Medicines Evaluation Agency ("EMEA")
of (i) a BLA filed by ATIII LLC for the use of tgATIII for the treatment of
sepsis or (ii) an amendment to the BLA previously filed by ATIII LLC and
approved by the FDA of a Major Market Country or by the EMEA to add sepsis as an
additional indication for tgATIII.

Each of the aforementioned payments described in clauses (b) and (c) above shall
be made in United States dollars by certified or bank check or by wire transfer
within thirty (30) days following the occurrence and confirmation of each event.

     4.5.   BOOKS OF ACCOUNT; AUDIT. ATIII LLC shall keep and maintain proper
and complete books of account. GTC shall initially keep and maintain such books
on behalf of ATIII

                                       16
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LLC for the 1998 calendar year. No later than October 31st of each year, the
Steering Committee shall select either Genzyme or GTC to keep and maintain such
books on behalf of ATIII LLC for the subsequent calendar year (beginning as of
January 1st of such year). In the event that either GTC or Genzyme reasonably
deems the Program to be material to GTC or Genzyme, as the case may be, for
financial accounting purposes, then, upon such Party's request, audited
financial statements of ATIII LLC shall be prepared by an independent accounting
firm to be selected by the Steering Committee. Each of GTC and Genzyme shall
keep and maintain proper and complete records and books of account documenting
all Program Costs incurred by it. Each of ATIII LLC, GTC and Genzyme shall
permit independent accountants retained by the other Parties to have access to
its records and books for the sole purpose of determining the appropriateness of
Program Costs charged by the non- auditing Party hereunder. Such examination
shall be conducted during regular business hours and upon reasonable notice, at
the auditing Party's own expense and no more than once in each calendar year
during the term of this Agreement and once during the three (3) calendar years
following the termination hereof. If such examination reveals that such Program
Costs have been misstated, any adjustment shall be promptly refunded or paid, as
appropriate. The auditing Party shall pay the fees and expenses of the
accountant engaged to perform the audit, unless such audit reveals an overcharge
of five percent (5%) or more for the period examined, in which case the Party
who received such overpayment shall pay all reasonable costs and expenses
incurred by the auditing Party in the course of making such determination,
including the fees and expenses of the accountant.

                       ARTICLE 5. THE DEVELOPMENT PROGRAM

     5.1.   CONDUCT OF THE DEVELOPMENT PROGRAM.

            5.1.1   GENERAL. The Parties each agree to collaborate diligently in
the development of Collaboration Products in the Field and to use commercially
reasonable and diligent efforts to develop, obtain Regulatory Approvals for and
bring to market Collaboration Products in the Field and in the Territory as soon
as practicable, all in accordance with the Development Plan and the
Commercialization Plan for such Collaboration Products. The Parties agree to
execute and substantially perform and to cooperate with each other in carrying
out the Development Plan and the Commercialization Plan for each Collaboration
Product. Neither GTC nor Genzyme shall be required to undertake activities in
furtherance of the Development Plan or Commercialization Plan in the absence of
funding from ATIII LLC pursuant to the provisions of this Agreement. As used in
this Agreement, the term "COMMERCIALLY REASONABLE AND DILIGENT EFFORTS" will
mean that level of effort which, consistent with the exercise of prudent
scientific and business judgment, is applied by the Party in question to its
other therapeutic products at a similar stage of development and with similar
commercial potential.

            5.1.2   DEVELOPMENT PLAN. The Development Program shall be conducted
by the Parties for ATIII LLC under a Development Plan which shall describe the
proposed overall program of development for each Collaboration Product,
including preclinical studies, toxicology, formulation, clinical trials and
regulatory plans and other key elements necessary to obtain Regulatory Approvals
for such Collaboration Product. Pursuant to the Development Plan, development
work may be subcontracted to Genzyme and GTC, at fully absorbed costs determined
by accepted accounting principals. The respective charges to ATIII LLC shall be
invoiced following completion of the work, and shall be payable by ATIII LLC
within a

                                       17
<Page>

commercially reasonable time thereafter (but in no event later than forty-five
(45) days of the date of invoice therefor). The Development Plan shall include a
summary of estimated Development Costs expected during the development process
through obtaining such Regulatory Approvals and a detailed description of and
budget for all development activities proposed for each calendar year for each
Collaboration Product. Until the initial Commercialization Plan is submitted in
accordance with Section 6.1.2 below, the Development Plan shall also include a
summary of estimated New Facility Costs expected during the period through
obtaining Regulatory Approval for the New Facility and a detailed description of
and budget for all activities related to the design, construction, validation
and operation of the New Facility proposed for the calendar year to which the
Development Plan relates.

            5.1.3   INITIAL AND UPDATED DEVELOPMENT PLAN. A preliminary initial
Development Plan for the period beginning on the Effective Date and ending on
December 31, 1998 has been prepared by GTC. The Program Management Team shall
submit a definitive initial Development Plan for the period beginning on the
Effective Date and ending on December 31, 1998 to the Steering Committee for
review and approval not later than thirty (30) days after the Effective Date.
Upon such approval, the definitive initial Development Plan shall be signed by
an authorized representative of each of Genzyme and GTC. The Development Plan
shall be updated annually by the Program Management Team and submitted to the
Steering Committee for review and approval not later than sixty (60) days prior
to January 1 of each year during the Development Program. Each such updated
Development Plan shall include (a) an overall development plan for each
Collaboration Product which sets forth all major development tasks remaining to
be accomplished prior to submission of filings for Regulatory Approvals, (b) a
detailed description and budget for the development and pre-commercialization
activities proposed for the forthcoming calendar year and (c) until the initial
Commercialization Plan is submitted in accordance with Section 6.1.2 below, (i)
an overall plan which sets forth all major tasks remaining to be accomplished
prior to submission of filings for Regulatory Approval of the New Facility and
(ii) a detailed description of and budget for all activities related to the
construction, validation and operation of the New Facility proposed for the
calendar year to which the Development Plan relates, in each case including
estimated time lines to accomplish such major tasks or detailed activities. The
Project Management Team shall be primarily responsible for preparing the annual
updates to the Development Plan and, in connection with the preparation of such
updates, shall consult with Genzyme and GTC regarding the identification, timing
and execution of and budget for the major tasks and detailed activities required
to perform the updated Development Plan. Each such updated Development Plan
approved by the Steering Committee shall be signed by an authorized
representative of each of GTC and Genzyme. The members of the Program Management
Team shall actively consult with one another throughout the term of the
Development Plan so as to adjust the specific work performed under the
Development Plan to conform to evolving developments in technology and the
results of the development work performed. While minor adjustments to the
Development Plan may be made from time to time upon approval of the Program
Management Team, significant changes in the scope or direction of the work and
any changes in funding exceeding one hundred five percent (105%) of the total
amount budgeted in any calendar year for the Development Program must be
approved by the Steering Committee, in the absence of which approval the most
recently approved Development Plan shall remain in effect. GTC and Genzyme shall
each submit reports to the Program Management Team no later than the tenth
(10th) business day of each calendar month stating such Party's estimate of the
amount by which

                                       18
<Page>

Development Costs incurred by such Party during the preceding calendar month
exceeded the amount budgeted for the work undertaken by such Party for such
month, if any.

            5.1.4   EXECUTION AND PERFORMANCE. The Development Program shall
allocate among the Parties responsibility for each of the activities described
therein. The Parties shall use commercially reasonable and diligent efforts to
conduct the activities described in the Development Plan. The Development Plan
shall be supervised by the Program Management Team. The Program Management Team
will coordinate preclinical and clinical testing of the Collaboration Products
and work with designated individuals at GTC and Genzyme in the preparation of
Regulatory Approval filings for the Collaboration Products and for the New
Facility.

            5.1.5   ATTENDANCE AT REGULATORY MEETINGS. Each Party shall provide
the others with prior notice of all meetings between representatives of the
notifying Party and regulatory authorities regarding any Collaboration Product.
Except as otherwise provided herein, the Party receiving such notice shall have
the right to have representatives present at all such meetings.

     5.2.   DEVELOPMENT INFORMATION.

            5.2.1   REPORTS AND INFORMATION EXCHANGE. ATIII LLC shall own all
clinical trial data accumulated from all clinical trials of Collaboration
Products conducted as part of the Program or otherwise funded or partially
funded by ATIII LLC. Each of GTC and Genzyme shall use commercially reasonable
and diligent efforts to disclose to ATIII LLC and to the other Party all
material information relating to any Collaboration Product promptly after it is
learned or its materiality is appreciated. The Party performing or supervising
clinical trials of Collaboration Products in accordance with the Development
Plan shall, on behalf and in the name of ATIII LLC, maintain the database of
clinical trial data accumulated from all clinical trials of Collaboration
Products and of adverse reaction information for all such Collaboration
Products. Each Party shall also keep the Program Management Team informed as to
its progress in the Development Plan. Within sixty (60) days following the end
of each calendar quarter during the Development Program, each of GTC and Genzyme
shall provide the other Parties with a reasonably detailed written report which
shall describe the progress to date of all activities for which such Party was
allocated responsibility during such quarter under the Development Plan.

            5.2.2   ADVERSE REACTION REPORTING. Each of GTC and Genzyme shall
notify the other Parties of any adverse reaction information relating to any
Collaboration Product within twenty-four (24) hours of the receipt of such
information and as necessary for compliance with regulatory requirements.
"ADVERSE REACTION INFORMATION" includes without limitation information relating
to any experience that (a) suggests a significant hazard, contraindication, side
effect or precaution, (b) is fatal or life threatening, (c) is permanently
disabling, (d) requires or prolongs inpatient hospitalization, (e) involves a
congenital anomaly, cancer or overdose or (f) is one not identified in nature,
specificity, severity or frequency in the current investigator brochure or the
United States labeling for the Collaboration Product.

            5.2.3   CLINICAL AND REGULATORY AUDITS. Each of GTC and Genzyme
shall permit ATIII LLC and the other Party or the representatives of ATIII LLC
or the other Party to have access during regular business hours and upon
reasonable advance notice, at the auditing Party's

                                       19
<Page>

own expense and no more than once in each calendar year during the term of this
Agreement, to the non-auditing Party's records and facilities relating to the
Development Program for the purpose of monitoring compliance with Good Clinical
Practice and other applicable requirements of the Regulatory Scheme.

     5.3.   REGULATORY APPROVAL FILINGS. Regulatory Approval filings in the
Territory for the Collaboration Products and for the facilities used to
manufacture such Collaboration Products shall be filed in the name of ATIII LLC
or, if required with respect to filings to be made with governmental authorities
or deemed to be in the best interest of the Parties by the Steering Committee,
in the name of such other entity as may be agreed upon by the Steering Committee
(such as filings with European regulatory authorities). Prior to submission to
the FDA, the Parties, through the Program Management Team, shall consult,
cooperate in preparing and mutually agree on the content and scope of the
Regulatory Approval filings. In the event that Regulatory Approvals are required
to be filed in the name of an entity other than ATIII LLC, the Steering
Committee shall ensure that a duly authorized officer of such entity agrees in
writing that (a) such entity shall hold the licenses issued in respect of such
Regulatory Approval filings and maintain control over the manufacturing
facilities and equipment to the extent required by the Regulatory Scheme, (b)
such entity shall provide manufacturing and supply services to ATIII LLC (i) at
the Fully Absorbed Cost of Goods of Collaboration Products so manufactured and
supplied and (ii) in accordance with the terms and conditions set forth in
Article 7 hereof, and shall reimburse ATIII LLC for any New Facility Costs
incurred in connection with the use of such facilities for the manufacture and
supply of such Collaboration Products, (c) the Parties shall have an irrevocable
right of access and reference to such Regulatory Approval filings, licenses and
facilities and (d) such entity agrees to comply with the provisions of Article
13 hereof with respect to the ownership and/or disposition of such Regulatory
Approvals in the event this Agreement is terminated and to provide the level of
cooperation described in Section 14.1 hereof in connection therewith.

     5.4.   FACILITIES VISITS. Representatives of GTC and Genzyme may visit all
manufacturing sites and the sites of any clinical trials or other experiments
being conducted by the other Party or ATIII LLC in connection with the
Development Program. If requested by the other Party, GTC and Genzyme shall
cause appropriate individuals working on the Development Program to be available
for meetings at the location of the facilities where such individuals are
employed at times reasonably convenient to the Party responding to such request.

             ARTICLE 6. SALES, MARKETING AND ADMINISTRATIVE SERVICES

     6.1.   COMMERCIALIZATION PLANS.

            6.1.1   GENERAL. The commercialization of each Collaboration Product
shall be governed by a Commercialization Plan which shall describe the overall
plan for commercializing such Collaboration Product, including without
limitation (a) a comprehensive marketing, sales, pricing, manufacturing,
distribution and licensing strategy for such Collaboration Product in all
applicable countries, including the identification of any Third Parties engaged
or to be engaged in connection with such activities and the arrangements with
them that have been or are proposed to be agreed upon (including policies and
procedures for adjustments, rebates, bundling and the like), (b) estimated
launch date, market and sales forecasts, in numbers of patients and local

                                       20
<Page>

currency, and competitive analysis for such Collaboration Product, (c) a
detailed budget for the Commercialization Costs to be incurred in connection
with performing such Commercialization Plan, (d) reasonable due diligence
obligations to be met by Genzyme and any Third Party distributor selected by the
Steering Committee pursuant to Section 6.7 below with respect to
commercialization objectives to be achieved during the calendar year to which
the Collaboration Plan relates (such as minimum annual sales objectives), (e) a
detailed manufacturing plan, including (i) if Regulatory Approval for the New
Facility has not been obtained, an overall plan which sets forth all major tasks
remaining to be accomplished prior to submission of filings for Regulatory
Approval of the New Facility and (ii) a detailed description of and budget for
all activities related to the design, construction, validation and operation of
and the manufacture of Collaboration Products in the New Facility proposed for
the calendar year to which the Commercialization Plan relates and (f) a list of
the Major Market Countries for such Collaboration Product if the Steering
Committee has changed such list pursuant to Section 1.28 hereof.

            6.1.2   INITIAL AND UPDATED COMMERCIALIZATION PLANS. No later than
immediately prior to the completion of the submission of all Regulatory Approval
filings for a Collaboration Product in any given country, Genzyme shall develop
and submit to the Steering Committee for review and approval an initial
Commercialization Plan in accordance with its customary standard for a product
of comparable market potential, taking into consideration factors such as market
conditions, regulatory factors, competition and the costs and profits of such
Collaboration Product. Genzyme shall be primarily responsible for developing
each Commercialization Plan and, in connection therewith, shall consult with GTC
and any Third Party distributor selected by the Steering Committee pursuant to
Section 6.7 below regarding the identification, timing and execution of and
budget for the major commercialization tasks required to perform the
Commercialization Plan. Each Commercialization Plan shall be updated annually by
Genzyme, in consultation with GTC and any Third Party distributor selected by
the Steering Committee pursuant to Section 6.7 below as herein provided, and
shall be submitted to the Steering Committee for approval not later than sixty
(60) days prior to January 1 of each year. Each Commercialization Plan approved
by the Steering Committee shall be signed by an authorized representative of
each of GTC and Genzyme. While minor adjustments to the Commercialization Plan
may be made from time to time without Steering Committee approval, significant
changes in the scope or direction of the work and any changes in funding
exceeding one hundred five percent (105%) of the total amount budgeted in any
calendar year for the Commercialization Plan must be approved by the Steering
Committee, and in the absence of such approval, the provisions of the most
recently approved Commercialization Plan shall remain in effect.

     6.2.   EXCLUSIVE ENGAGEMENT. ATIII LLC hereby engages Genzyme on a
exclusive basis (except with respect to rights held by Centeon or as provided in
Section 6.7 below) to market and sell Collaboration Products within the
Territory for use within the Field. Genzyme hereby accepts such engagement and
agrees (by itself or through its Affiliates) to use commercially reasonable and
diligent efforts to establish each Collaboration Product in the markets, fulfill
market demand and meet the marketing and distribution goals set forth in the
Commercialization Plan for such Collaboration Product. The Parties acknowledge
that Centeon has certain rights with respect to the distribution and sale of
products in the Territory pursuant to the Original ATIII Agreement, and that
ATIII LLC may deem it necessary or advisable to grant

                                       21
<Page>

rights to Centeon in connection with any agreement entered into by Centeon and
ATIII LLC pursuant to Section 2.3 above.

     6.3.   ORDERS AND FORECASTING. Genzyme shall purchase the Collaboration
Products exclusively from ATIII LLC. Genzyme shall place orders for the
Collaboration Products with ATIII LLC on a purchase order setting forth the
quantity of Collaboration Products ordered, any specifications therefor and the
date required. ATIII LLC, on the date set forth in the applicable purchase
order, shall sell the Collaboration Products to Genzyme for resale within the
Territory. All freight, insurance, duties and all other charges associated with
shipment of the Collaboration Products shall be considered Commercialization
Costs for such Collaboration Products only to the extent such costs are not
charged to Genzyme's customers.

     6.4.   PRICES AND PAYMENT TERMS; COSTS.

            6.4.1   PRICES. Genzyme shall purchase Collaboration Products from
ATIII LLC at the Estimated Net Selling Price for such Collaboration Products
LESS the Distributor's Discount. The Distributor's Discount is intended by the
Parties to compensate Genzyme for acting as distributor for the Collaboration
Products.

            6.4.2   TERMS OF PAYMENT. Unless otherwise agreed by the Parties in
writing, payment by Genzyme to ATIII LLC for Collaboration Products shall be due
within sixty (60) days of the date of invoice therefor.

            6.4.3   MARKETING AND DISTRIBUTION EXPENSES. Genzyme's ordinary
expenses incurred in the course of performing its marketing and distribution
obligations hereunder shall constitute Commercialization Costs and, as such,
shall be reimbursed by ATIII LLC, but only to the extent that such amounts,
together with all other Commercialization Costs to date during such calendar
year, do not exceed one hundred five percent (105%) of the Commercialization
Costs budgeted in the Commercialization Plan then in effect for such calendar
year (except to the extent such excess is approved by the Steering Committee
pursuant to Section 6.1.2 above). Ordinary marketing and distribution expenses
include, but are not limited to, recruitment costs and salaries and associated
expenses for sales and marketing personnel and support staff, advertising and
promotion costs, transportation expenses including insurance (but only to the
extent not charged to customers and only such proportion of all such costs
directly attributable to support of the Commercialization Plan), duties and
taxes, bad debt expense, and costs associated with cash and other trade
discounts and allowances and other marketing concessions to customers actually
allowed and taken.

     6.5.   RESPONSIBILITIES OF GENZYME. Genzyme shall be solely responsible for
all aspects of the marketing of the Collaboration Products in accordance with
the strategy, policies and procedures established in the Commercialization Plan,
including without limitation the responsibilities described in this Section 6.5.

                    (a)  Genzyme shall be primarily responsible for the
implementation of each Commercialization Plan, including without limitation
setting all terms of sale, including establishing pricing policies, credit terms
and cash discounts and allowances, formulating

                                       22
<Page>

marketing  plans,  providing  patient  information,  providing  customer support
services, providing reimbursement counseling services and sales force training.

                    (b)  Genzyme shall employ sufficiently trained and
experienced individuals in numbers adequate to carry out its responsibilities
under this Article 6. Sales and support personnel shall be familiar with the
Collaboration Products and with competitive products and shall respond promptly
to customer requests for support.

                    (c)  Genzyme shall provide instructions and appropriate
training to customers in the proper use and handling of the Collaboration
Products and shall monitor performance of the Collaboration Products.

                    (d)  Prior to sale, Genzyme shall store, maintain and handle
Collaboration Products in accordance with the requirements of the Regulatory
Scheme and the normal and customary commercial practice with respect to
regulated medical products.

                    (e)  Genzyme shall comply with all laws and government
regulations applicable to the sale of Collaboration Products within the
Territory.

                    (f)  The Collaboration Products shall be sold under
trademarks selected by the Steering Committee and owned by or licensed to ATIII
LLC in accordance with Section 9.1.2 hereof.

                    (g)  Genzyme shall not (i) establish any branch, sales
offices, warehouses or other facilities outside the Territory with respect to
the Collaboration Products, (ii) adopt a policy of actively selling
Collaboration Products outside the Territory nor undertake the active sale or
promotion of sales of Collaboration Products outside the Territory or (iii) seek
customers or solicit orders from a prospective customer with its principal
address or place of business located outside the Territory. Without ATIII LLC's
prior consent, Genzyme may not deliver or tender, or cause to be delivered or
tendered, Collaboration Products outside of the Territory. Genzyme shall not
sell Collaboration Products to a customer if Genzyme knows that such customer
intends to remove those Collaboration Products from the Territory. If Genzyme
receives an order from a prospective customer located outside of the Territory
or who Genzyme knows intends to remove the Collaboration Products from the
Territory, Genzyme shall immediately refer that customer to GTC.

                    (h)  Genzyme shall maintain complete and accurate records of
all movements and transactions involving Collaboration Products by unit, by
batch number and by customer so that all such movements and transactions can be
traced quickly and effectively. Upon written request, Genzyme will provide
copies of such records to the other Parties, with access to facilities used by
Genzyme in performing its duties under this Article 6 during normal business
hours and upon reasonable advance notice for the purpose of inspecting such
facilities for compliance with the terms of this Agreement. The records
maintained by Genzyme pursuant to this clause (h) shall be subject to the other
Parties' audit rights under Section 4.5 hereof.

                    (i)  Within forty-five (45) days after the end of each
calendar quarter, Genzyme will report to ATIII LLC the actual prices at which
all sales of Collaboration Products were made to its customers during the
preceding calendar quarter, future prospects for the

                                       23
<Page>

Collaboration Products and related issues. Genzyme shall report promptly to the
Steering Committee in writing the occurrence of each material incident of
Collaboration Product performance required to be reported to regulatory
authorities, including without limitation adverse reaction information in
accordance with Section 5.2.2 hereof.

     6.6.   RESPONSIBILITIES OF ATIII LLC AND GTC. ATIII LLC shall supply
Collaboration Products to Genzyme in accordance with purchase orders placed
pursuant to Section 6.3 above. Neither ATIII LLC nor GTC shall actively solicit
for its own account sales of Collaboration Products in the Territory. Any
solicitations or requests to purchase Collaboration Products received by ATIII
LLC or GTC from any customer or prospective customer with its principal address
or place of business located in the Territory or who ATIII LLC or GTC, as the
case may be, knows intends to use the Collaboration Products in the Territory or
ship such Collaboration Products into the Territory shall be immediately
referred to Genzyme.

     6.7.   THIRD PARTY DISTRIBUTORS. In the event that Genzyme fails to use
commercially reasonable and diligent efforts to establish a Collaboration
Product in a country identified in the Commercialization Plan for such
Collaboration Product, or to fulfill market demand or meet the marketing and
distribution goals for such country as set forth in the Commercialization Plan
for such Collaboration Product, and such failure to perform is not cured within
ninety (90) days of written notice thereof from GTC, then (a) GTC may elect to
cause Genzyme's rights under Section 6.2 hereof to market and sell such
Collaboration Product in such country to terminate and (b) the Steering
Committee shall promptly select a Third Party to be engaged by ATIII LLC to
market and sell such Collaboration Product in such country; PROVIDED, HOWEVER,
that in the event that any such country is a Major Market Country, any election
made by GTC pursuant to clause (a) hereof shall be in lieu of any right to
terminate this Agreement that may arise under Section 13.2.1 (c) hereof with
respect to such failure to perform; PROVIDED FURTHER that any such termination
of Genzyme's rights under Section 6.2 hereof shall be on a country-by-country
basis and Genzyme's rights and obligations under Section 6.2 hereof with respect
to other Collaboration Products in such country and with respect to the rest of
the Territory shall remain in full force and effect. Any such Third Party
distributor selected by the Steering Committee pursuant to clause (b) above
shall be required to execute a written agreement with ATIII LLC pursuant to
which such Third Party shall agree to (i) use commercially reasonable and
diligent efforts to comply with the strategy, policies and procedures set forth
in each Commercialization Plan for such country, including without limitation
the responsibilities described in Section 6.5 above (with references therein to
Genzyme being deemed to refer to such Third Party and references therein to the
Territory being deemed to refer to the applicable country for purposes of this
clause (i)) and (ii) reasonably cooperate with Genzyme in the preparation of
each Commercialization Plan or update thereto for such Collaboration Product.

     6.8.   GENERAL AND ADMINISTRATIVE SERVICES. General and administrative
services required by ATIII LLC shall be provided at cost by either or both of
GTC and Genzyme as determined by the Steering Committee. All such costs, in
addition to general and administrative costs payable to Third Parties (such as
accountants) and general and administrative costs incurred by GTC and Genzyme in
satisfying their respective obligations under this Agreement, shall be
considered to be Program Costs.

                        ARTICLE 7. MANUFACTURE AND SUPPLY

                                       24
<Page>

     Subject to the terms and conditions of this Agreement, Collaboration
Products shall be manufactured and supplied for preclinical and clinical testing
and for commercial sale upon the following terms and conditions:

     7.1.   PROCESS DEVELOPMENT; MANUFACTURING APPROVALS. The Parties will use
commercially reasonable and diligent efforts to develop a process for the
manufacture of each Collaboration Product and to scale up that process to a
scale sufficient to manufacture and supply (a) the anticipated demand for
preclinical studies and clinical trials of such Collaboration Product in
accordance with the projections set forth in the Development Plan and (b) the
anticipated market demand for such Collaboration Product at the time Regulatory
Approval is obtained for such Collaboration Product in accordance with the
projections set forth in the Commercialization Plan for such Collaboration
Product. The development of the process for the manufacture of Collaboration
Products as well as the scale up of such process and all material issues
incident to the development of the ability to produce Collaboration Products for
commercial purposes in sufficient quantity and in a timely manner will be within
the purview of the Program Management Team. The Parties will use commercially
reasonable and diligent efforts, and will cause any approved Third Party
supplier, to make filings necessary to obtain approval of any license
application for the New Facility which may be required as part of any Regulatory
Approval for the first Collaboration Product.

     7.2.   MANUFACTURE AND SUPPLY OF COLLABORATION PRODUCTS. ATIII LLC shall
manufacture and supply Collaboration Products for preclinical and clinical
activities and commercial sale on the following terms and conditions:

            7.2.1   GENERAL. ATIII LLC shall use commercially reasonable and
diligent efforts to manufacture and supply Collaboration Products (a) for
preclinical studies and clinical trials in quantities and within a time period
sufficient to conduct the activities set forth in the Development Plan and (b)
to meet market demand for Collaboration Products ordered in accordance with the
terms hereof. ATIII LLC may subcontract with GTC, Genzyme and Third Parties for
the manufacture or packaging of Collaboration Products, as determined by the
Steering Committee. In this regard, it is agreed that ATIII LLC will subcontract
with GTC for the manufacture and supply of Collaboration Products (i) in
clinical trial grade for preclinical and clinical trials, for which GTC shall be
entitled to charge ATIII LLC an amount equal to GTC's Fully Absorbed Cost of
Goods for such Collaboration Products, and (ii) in bulk form (i.e., generate raw
milk containing tg ATIII) ("BULK MANUFACTURING") for use in connection with
commercialization activities, for which GTC shall be entitled to charge to ATIII
LLC an amount equal to GTC's Fully Absorbed Cost of Goods for such Collaboration
Products PLUS, with respect to Collaboration Products intended for commercial
sale only, the Manufacturer's Profit. GTC agrees to use commercially reasonable
and diligent efforts in performing such work. It is further agreed that the work
required to produce the Collaboration Products in clinical trial grade for
preclinical and clinical trials and in finished form, including without
limitation performance of assays and purification and packaging ("FINISH
PROCESSING"), will be subcontracted to Genzyme, for which Genzyme shall be
entitled to charge to ATIII LLC its Fully Absorbed Costs of Goods for such
Collaboration Products. Genzyme agrees to use commercially reasonable and
diligent efforts in performing such work. Notwithstanding the foregoing
provisions of this Section 7.2.1, to the extent required by the Regulatory
Scheme, any entity selected by the Steering Committee pursuant to Section 5.3
above may be engaged by ATIII LLC to manufacture Collaboration

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Products. The respective charges to ATIII LLC shall be invoiced following
completion of the work, and shall be payable by ATIII LLC within a commercially
reasonable time thereafter (but in no event later than forty-five (45) days of
the date of invoice therefor). The costs of any failed or discarded lots shall
be borne by the Party responsible therefor and shall not be considered Program
Costs.

            7.2.2   MANUFACTURING FACILITIES AND CAPACITY REQUIREMENTS. Supplies
of the Collaboration Product for preclinical and clinical trials and
commercialization activities will be manufactured in the facilities currently
being used for the manufacture of the Collaboration Products as of the Date of
Execution. The Parties acknowledge that in the event that the Steering Committee
determines that it is necessary or advisable to use a New Facility for the
manufacture of the Collaboration Products, the capital costs therefor shall be
borne by GTC and Genzyme pursuant to Sections 1.36, 1.41 and 4.1.3 hereof. The
Steering Committee shall approve the design and capacity requirements for the
New Facility.

            7.2.3   FORECASTS. The Program Management Team shall establish a
procedure for providing forecasts of customer orders for Collaboration Products
pursuant to Section 6.3 above, updating such forecasts and ordering
Collaboration Product, in each case within time periods sufficient to enable
ATIII LLC to manufacture such Collaboration Products to meet such forecasts in a
commercially reasonable and diligent manner.

     7.3.   CERTIFICATES OF ANALYSIS. ATIII LLC, Genzyme or GTC, as appropriate,
shall perform, or cause its contract manufacturer(s) to perform, quality
assurance and control tests on each lot of Collaboration Products bulk
manufactured or finish processed pursuant to this Agreement before delivery and
shall prepare, or cause its contract manufacturer(s) to prepare and deliver, a
written report of the results of such tests (the Party manufacturing a lot of
Collaboration Product is referred to in this Article 7 as the "MANUFACTURING
PARTY"). Each test report shall set forth for each lot delivered the items
tested, specifications and results in a certificate of analysis containing the
types of information which shall have been approved by the Program Management
Team or required by the FDA or other applicable regulatory authority. The
Manufacturing Party shall maintain such certificates for a period of not less
than five (5) years from the date of manufacture and for so long as required
under applicable requirements of the FDA or other applicable regulatory
authority.

     7.4.   CERTIFICATES OF MANUFACTURING COMPLIANCE. The Manufacturing Party
shall prepare, or cause its contract manufacturer(s) to prepare and deliver, and
maintain for a period of not less than five (5) years and for so long as
required under applicable requirements of the FDA or other applicable regulatory
authority for each lot of Collaboration Products manufactured a certificate of
manufacturing compliance containing the types of information which shall have
been approved by the Program Management Team or required by the FDA or other
applicable regulatory authority, which certificate will certify that the lot of
Collaboration Products was manufactured in accordance with the Specifications
and the Good Manufacturing Practices of the FDA or other applicable regulatory
authority as the same may be amended from time to time. The Manufacturing Party
shall advise the other Parties immediately if an authorized agent of the FDA or
other regulatory authority visits any of the Manufacturing Party's manufacturing
facilities, or the facilities where the Collaboration Products are being
manufactured, for an inspection with respect to the Collaboration Products. The
Manufacturing Party shall furnish to

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the other Parties the report by such agency of such visit, to the extent that
such report relates to Collaboration Products, within ten (10) business days of
the Manufacturing Party's receipt of such report.

     7.5.   ACCESS TO FACILITIES. Each Party shall have the right to inspect
those portions of the manufacturing, finish processing or storage facilities of
the Manufacturing Party where Collaboration Products are being manufactured,
finished or stored, or any subcontractor who is manufacturing, finishing or
storing Collaboration Products for the Manufacturing Party, at any time during
regular business hours and upon reasonable advance notice to ascertain
compliance with the Good Manufacturing Practices of the FDA or other applicable
regulatory authority, as the same may be amended from time to time. Any
confidential information disclosed to or otherwise gathered by the Party
conducting such inspection during any such inspection shall be deemed
"Information" as defined in Section 10.1 below.

                              ARTICLE 8. MANAGEMENT

     8.1.   PROGRAM MANAGEMENT TEAM.

            8.1.1   GENERAL. The Parties have established a Program Management
Team to oversee and control development of Collaboration Products and to prepare
for and oversee the launch of Collaboration Products. The Program Management
Team is and shall continue to be composed of four (4) representatives appointed
by GTC and four (4) representatives appointed by Genzyme. Such representatives
will include individuals with expertise and responsibilities in such areas as
preclinical development, clinical development, manufacturing, regulatory
affairs, marketing, sales management and reimbursement. The Program Management
Team shall meet as needed but not less than bi-weekly. The Program Management
Team shall appoint one of its members to act as Secretary. Such meetings shall
be at times and places or in such form (e.g., telephone or video conference) as
the members of the Program Management Team shall agree. A Party may change one
or more of its representatives to the Program Management Team at any time.
Members of the Program Management Team may be represented at any meeting by
another member of the Program Management Team or by a deputy. Any approval,
determination or other action agreed to by a majority of the members of the
Program Management Team appointed by each of GTC and Genzyme or their deputies
present at the relevant Team meeting shall be the approval, determination or
other action of the Program Management Team, provided at least two (2)
representatives of each of GTC and Genzyme are present at such meeting.
Representatives of either GTC and Genzyme who are not members of the Program
Management Team may attend meetings of the Program Management Team as agreed to
by the representative members of the other Party. The Program Management Team
may designate project leaders to the extent it deems it necessary or advisable.

            8.1.2   DEVELOPMENT PROGRAM FUNCTIONS. During the term of the
Development Program, the Program Management Team shall coordinate, expedite and
control the development of Collaboration Products to obtain Regulatory
Approvals. The Program Management Team will (a) develop and recommend to the
Steering Committee Development Plans (including annual development budgets), (b)
facilitate the flow of information with respect to development work being
conducted for each Collaboration Product throughout the Territory and (c)
discuss and cooperate regarding the conduct of such development work.

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<Page>

            8.1.3   COMMERCIALIZATION FUNCTIONS. Following submission of filings
for Regulatory Approvals for the first Collaboration Product, the Program
Management Team shall function as the operational staff of ATIII LLC and the
functions of the Program Management Team shall be expanded to include: (a)
monitoring the commercialization of Collaboration Products pursuant to the
Commercialization Plan, including oversight of planning, annual budgeting,
manufacturing, marketing, sales and distribution, and licensing of Collaboration
Products; (b) monitoring actual expenses incurred in the manufacture, marketing,
sale and distribution of Collaboration Products; and (c) facilitating
cooperation regarding the commercialization and marketing activities of the
Parties.

            8.1.4   MINUTES. The Program Management Team shall keep accurate
minutes of its deliberations which shall record all proposed decisions and all
actions recommended or taken. The Secretary shall be responsible for the
preparation of draft minutes. Draft minutes shall be sent to all members of the
Program Management Team within five (5) working days after each meeting. All
records of the Program Management Team shall at all times be available to all of
the Parties.

     8.2.   STEERING COMMITTEE.

            8.2.1   GENERAL. The Parties have established a Steering Committee
to oversee and manage the collaboration contemplated by this Agreement. The
Steering Committee is and shall continue to be composed of three (3)
representatives appointed by GTC and three (3) representatives appointed by
Genzyme. Such representatives will be senior officers and/or managers of their
respective companies. Genzyme and GTC shall each designate one (1) of their
respective representatives on the Steering Committee to act as Co-Chairman. The
Steering Committee shall appoint one (1) of its members to act as Secretary. The
Steering Committee will meet as needed but not less than once each calendar
quarter. Such meetings shall be at times and places or in such form (e.g.,
telephone or video conference) as the members of the Steering Committee shall
agree. A Party may change one or more of its representatives to the Steering
Committee at any time. Members of the Steering Committee may be represented at
any meeting by another member of the Steering Committee or by a deputy. Any
approval, determination or other action agreed to by unanimous consent of the
members of the Steering Committee or their deputies present at the relevant
Steering Committee meeting shall be the approval, determination or other action
of the Steering Committee, provided at least two (2) representatives of each of
GTC and Genzyme are present at such meeting. Representatives of either GTC and
Genzyme who are not members of the Steering Committee may attend meetings of the
Steering Committee as agreed to by the representative members of the other
Party.

            8.2.2   FUNCTIONS. The Steering Committee shall perform the
following functions: (a) determine the overall strategy for the Program in the
manner contemplated by this Agreement; (b) coordinate the activities of the
Parties hereunder; (c) settle disputes or disagreements that are unresolved by
the Program Management Team; (d) approve any agreements with Third Parties
regarding a Collaboration Product or which involve the grant of any rights
related to the development, manufacture or marketing of a Collaboration Product;
(e) review and approve each Development Plan, including each significant change
and annual update thereto, submitted to it pursuant to Section 5.1.3 hereof; (f)
review and approve each Commercialization Plan, including each significant
change and annual update thereto, submitted

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<Page>

to it for approval pursuant to Section 6.1.2 hereof; (g) serve as the governing
body of ATIII LLC; (h) set the Distributor's Discount, the Estimated Fully
Absorbed Cost of Goods, the Estimated Net Selling Price and the Manufacturer's
Profit for each Collaboration Product; (i) add or remove countries from the list
of Major Market Countries for each Collaboration Product pursuant to Section
1.28 hereof; (j) select any Third Party distributor to be engaged by ATIII LLC
pursuant to Section 6.7 above; and (k) perform such other functions as
appropriate to further the purposes of this Agreement as determined by the
Parties. The Steering Committee shall use its best efforts to ensure that the
relative cumulative amounts of Distribution Margin and the Manufacturing Margin
for each Collaboration Product are proportionate to the relative Percentage
Interests of Genzyme and GTC. In the event that (I) the relative amounts of the
Distribution Margin and the Manufacturing Margin for a Collaboration Product are
disproportionate to the relative Percentage Interests of Genzyme and GTC with
respect to any two (2) consecutive calendar quarters or (II) Genzyme and GTC's
Percentage Interests are adjusted pursuant to Section 4.1.4 hereof, the Steering
Committee shall promptly adjust the Distributor's Discount and/or the
Manufacturer's Profit, as appropriate, to comply with the preceding sentence.

            8.2.3   MINUTES. The Steering Committee shall keep accurate minutes
of its deliberations which shall record all proposed decisions and all actions
recommended or taken. The Secretary shall be responsible for the preparation of
draft minutes. Draft minutes shall be sent to all members of the Steering
Committee within ten (10) working days after each meeting. All records of the
Steering Committee shall at all times be available to both GTC and Genzyme.

     8.3.   GENERAL DISAGREEMENTS. All disagreements within the Program
Management Team and the Steering Committee shall be subject to the following:

            (a) The representatives to the Program Management Team or Steering
     Committee will negotiate in good faith for a period of not less than thirty
     (30) days to attempt to resolve the dispute. In the case of the Program
     Management Team, any unresolved dispute shall be referred to the Steering
     Committee for good faith negotiations for an additional period of not less
     than thirty (30) days to attempt to resolve the dispute.

            (b) In the event that the dispute is not resolved after the period
     specified in clause (a), the representatives shall promptly present the
     disagreement to the Chief Executive Officers of GTC and Genzyme or a
     designee of such Chief Executive Officer reasonably acceptable to the other
     Party.

            (c) Such executives shall meet or discuss in a telephone or video
     conference each of GTC and Genzyme's views and explain the basis for such
     dispute.

            (d) If such executives cannot resolve such disagreement within sixty
     (60) days after such issue has been referred to them, then such dispute
     shall be referred to arbitration as described in Section 14.11 hereof.

                     ARTICLE 9. INTELLECTUAL PROPERTY RIGHTS

     9.1.   OWNERSHIP. The Parties acknowledge that the ownership rights set
forth herein (a) shall not be affected by the participation in the discovery or
development of an Invention (as

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defined below) by the Program Management Team or the Steering Committee in the
course of discharging their duties hereunder and (b) are subject to the license
grants set forth in Article 3 above.

            9.1.1   OWNERSHIP AND ASSIGNMENT OF DISCOVERIES AND IMPROVEMENTS.
All right, title and interest in all writings, inventions, discoveries,
improvements and other technology, whether or not patentable or copyrightable,
and any patent applications, patents or copyrights based thereon (collectively,
the "INVENTIONS") that are discovered, made or conceived during and in
connection with the Program solely by employees of GTC or others acting on
behalf of GTC ("GTC INVENTIONS") shall be owned by GTC. All right, title and
interest in all Inventions that are discovered, made or conceived during and in
connection with the Program solely by employees of Genzyme or others acting on
behalf of Genzyme ("GENZYME INVENTIONS") shall be owned by Genzyme. All right,
title and interest in all Inventions that are discovered, made or conceived
during and in connection with the Program jointly by employees of GTC and
Genzyme ("JOINT INVENTIONS") shall be jointly owned by Genzyme and GTC. Each of
GTC and Genzyme shall promptly disclose to ATIII LLC and the other Party the
making, conception or reduction to practice of Inventions by employees or others
acting on behalf of such Party. All GTC Inventions, Genzyme Inventions and Joint
Inventions shall be automatically licensed to ATIII LLC pursuant to Section 3.1
hereof.

            9.1.2   OWNERSHIP OF TRADEMARKS. The Steering Committee shall select
and ATIII LLC shall own all trademarks for the sale and use of Collaboration
Products in the Territory, and all expenses thereof shall be considered Program
Costs. All such trademarks shall be registered in the name of ATIII LLC if and
when registered. In the event that the applicable laws and regulations of any
country in which the Steering Committee elects to register any such trademark
require that such trademark be registered in the name of an entity other than
ATIII LLC, or if the Steering Committee determines that it is in the best
interests of the parties, then the Steering Committee shall select such entity
and ensure that a duly authorized officer of such entity agrees in writing that
such entity shall (a) grant ATIII LLC an exclusive, fully-paid, royalty-free,
irrevocable (during the term of this Agreement) right and license (with the
right to grant sublicenses) to use such trademark in the Territory and (b)
comply with the provisions of Article 13 hereof with respect to the ownership
and/or disposition of such trademark in the event this Agreement is terminated
and provide the level of cooperation described in Section 14.1 hereof in
connection therewith.

            9.1.3   COOPERATION OF EMPLOYEES. Each of GTC and Genzyme represents
and agrees that all employees or others acting on its behalf in performing its
obligations under this Agreement shall be obligated under a binding written
agreement to assign to such Party, or as such Party shall direct, all Inventions
made or conceived by such employee or other person. In the case of non-employees
working for other companies or institutions on behalf of GTC or Genzyme, GTC or
Genzyme, as applicable, shall have the right to obtain licenses for all
Inventions made by such non-employees on behalf of GTC or Genzyme, as
applicable, in accordance with the policies of said company or institution. GTC
and Genzyme agree to undertake to enforce such agreements (including, where
appropriate, by legal action) considering, among other things, the commercial
value of such Inventions.

     9.2.   FILING, PROSECUTION AND MAINTENANCE OF PATENT RIGHTS.

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<Page>

            9.2.1   FILING, PROSECUTION AND MAINTENANCE. Each of GTC and Genzyme
shall be responsible for the filing, prosecution and maintenance of all patent
applications and patents which make up its Patent Rights. The Steering Committee
shall designate either GTC or Genzyme as the Party responsible for the filing,
prosecution and maintenance of all patent applications and patents which make up
the Genzyme/GTC Patent Rights. For so long as any of the license grants set
forth in Article 3 hereof remain in effect and upon request of the other Party,
each of GTC and Genzyme agrees to file and prosecute patent applications and
maintain the patents covering the Patent Rights for which it is responsible in
all countries in the Territory selected by the Steering Committee. Each of GTC
and Genzyme shall consult with and keep the other fully informed of important
issues relating to the preparation and filing (if time permits), prosecution and
maintenance of such patent applications and patents, and shall furnish to the
other Party copies of documents relevant to such preparation, filing,
prosecution or maintenance in sufficient time prior to filing such document or
making any payment due thereunder to allow for review and comment by the other
Party and, to the extent possible in the reasonable exercise of its discretion,
the filing Party shall incorporate all such comments.

            9.2.2   PATENT FILING COSTS. All costs associated with filing,
prosecuting and maintaining patent applications and patents covering each of GTC
and Genzyme's Patent Rights and the Genzyme/GTC Patent Rights specific to the
Field in the Territory shall be deemed Development Costs; PROVIDED, HOWEVER,
that if the claims of any such Patent Rights include claims outside the Field,
each of ATIII LLC and the Party filing, prosecuting and maintaining such patents
and patent applications shall bear one-half (1/2) of such costs itself and the
other half of such costs shall be deemed Development Costs.

     9.3.   COOPERATION. Each of GTC and Genzyme shall make available to the
other Party (or to the other Party's authorized attorneys, agents or
representatives) its employees, agents or consultants to the extent necessary or
appropriate to enable the appropriate Party to file, prosecute and maintain
patent applications and resulting patents with respect to inventions owned by a
Party and for periods of time sufficient for such Party to obtain the assistance
it needs from such personnel. Where appropriate, each of GTC and Genzyme shall
sign or cause to have signed all documents relating to said patent applications
or patents at no charge to the other Party.

     9.4.   NOTIFICATION OF PATENT TERM RESTORATION. Each of GTC and Genzyme
shall notify the other Party of (a) the issuance of each United States patent
included within the Patent Rights for which the notifying Party is responsible,
giving the date of issue and patent number for each such patent, and (b) each
notice pertaining to any patent included within the Patent Rights for which the
notifying Party is responsible which it receives as patent owner pursuant to the
Drug Price Competition and Patent Term Restoration Act of 1984, including
notices pursuant to Sections 101 and 103 of such Act from persons who have filed
an abbreviated NDA. Such notices shall be given promptly, but in any event
within ten (10) business days after receipt of each such notice pursuant to such
Act. Each of GTC and Genzyme shall notify the other Party of each filing for
patent term restoration under such Act, any allegations of failure to show due
diligence and all awards of patent term restoration (extensions) with respect to
the Patent Rights for which the notifying Party is responsible.

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<Page>

     9.5.   NO OTHER TECHNOLOGY RIGHTS. Except as otherwise expressly provided
in this Agreement, under no circumstances shall a Party hereto, as a result of
this Agreement, obtain any ownership interest in or other right to the Patent
Rights, Technology or Manufacturing Know-How of the other Party, including items
owned, controlled or developed by the other Party, or transferred by the other
Party to said Party at any time pursuant to this Agreement. It is understood and
agreed that this Agreement does not grant either Party any license or other
right in the Patent Rights of the other Party for uses other than as specified
in Article 3 hereof and this Article 9.

     9.6.   ENFORCEMENT OF PATENT RIGHTS; DEFENSE OF INFRINGEMENT ACTIONS. GTC
and Genzyme shall each promptly notify the other in writing of any alleged or
threatened infringement of any patents or patent applications for which it is
responsible pursuant to Section 9.2 above or if either Party, or any of their
respective Affiliates, shall be individually named as a defendant in a legal
proceeding by a Third Party for infringement of a patent because of the
manufacture, use or sale of a Collaboration Product or because of attempts to
invalidate Patent Rights.

            9.6.1   FIRST RIGHT TO RESPOND. Each of GTC and Genzyme shall have
the first right to respond to or defend (in consultation with the Steering
Committee) against such challenge or infringement of the Patent Rights for which
it is responsible pursuant to Section 9.2 above or charge of infringement. In
the event such Party elects to so respond or defend, the other Party will
cooperate with the responding Party's legal counsel, join in such suits as may
be brought by the responding Party to enforce its Patent Rights, and be
available at the responding Party's reasonable request to be an expert witness
or otherwise to assist in such proceedings.

            9.6.2   SHARING OF LITIGATION AND SETTLEMENT EXPENSES. The costs
incurred (a) in responding to or defending against a challenge to or
infringement of a Party's Patent Rights specific to the Field or a charge that
the manufacture, use or sale of Collaboration Products infringe upon the Patent
Rights of Third Parties, (b) in settling any such actions, which may not be done
without the prior written consent of the Steering Committee, and (c) as damages
paid as a result of such actions shall be deemed Program Costs.

            9.6.3   SECOND RIGHT TO RESPOND. If a Party does not exercise its
right to respond to or defend against challenges or infringements of its Patent
Rights as provided in Section 9.6.1 above within sixty (60) days of becoming
aware of or being notified of such challenges or infringements, then the other
Party shall have the option to do so at its sole cost; PROVIDED that in such
case all amounts so recovered from such Third Party shall be retained by the
Party undertaking such response or defense and the Party so responding shall
have no further obligations to the other Party with respect to the response or
defense thereof.

                           ARTICLE 10. CONFIDENTIALITY

     10.1.  NONDISCLOSURE OBLIGATIONS. Except as otherwise provided in this
Article 10, during the term of this Agreement and for a period of five (5) years
thereafter, the Parties shall maintain in confidence and use only for purposes
specifically authorized under this Agreement (a) confidential information and
data resulting from or related to the development of

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Collaboration Products and (b) all information and data not described in clause
(a) but supplied by the other Party under this Agreement and marked or
identified as "Confidential".

     For purposes of this Article 10, information and data described in clause
(a) or (b) of the preceding paragraph shall be referred to as "INFORMATION." To
the extent it is reasonably necessary or appropriate to fulfil its obligations
or exercise its rights under this Agreement, a Party may disclose Information it
is otherwise obligated under this Section not to disclose to its Affiliates,
sublicensees, consultants, outside contractors and clinical investigators, on a
need-to-know basis and on the condition that such entities or persons agree to
keep the Information confidential for the same time periods and to the same
extent as such Party is required to keep the Information confidential; and a
Party or its sublicensees may disclose such Information to government or other
regulatory authorities to the extent that such disclosure is reasonably
necessary to obtain patents or authorizations to conduct clinical trials with
and to market commercially Collaboration Products. The obligation not to
disclose Information shall not apply to any part of such Information that: (i)
is or becomes patented, published or otherwise becomes publicly known other than
by acts of the Party obligated not to disclose such Information or its
Affiliates or sublicensees in contravention of this Agreement; (ii) can be shown
by written documents to have been disclosed to the receiving Party or its
Affiliates or sublicensees by a Third Party, PROVIDED that such Information was
not obtained by such Third Party directly or indirectly from the other Party
under this Agreement; (iii) prior to disclosure under this Agreement, was
already in the possession of the receiving Party or its Affiliates or
sublicensees, PROVIDED that such Information was not obtained directly or
indirectly from the other Party under this Agreement; (iv) can be shown by
written documents to have been independently developed by the receiving Party or
its Affiliates without breach of any of the provisions of this Agreement; or (v)
is disclosed by the receiving Party pursuant to a subpoena lawfully issued by a
court or governmental agency, PROVIDED that the receiving Party notifies the
other Party immediately upon receipt of any such subpoena.

     10.2.  TERMS OF THIS AGREEMENT; PRESS RELEASES. The Parties further agree
to seek confidential treatment for the filing of this Agreement with the
Securities and Exchange Commission and shall agree upon the content of the
request for confidential treatment made by each Party in respect of such filing.
Except as permitted by the foregoing provisions or as otherwise required by law,
GTC and Genzyme each agree not to disclose any terms or conditions of this
Agreement to any Third Party without the prior consent of the other Party;
PROVIDED that each Party shall be entitled to disclose the terms of this
Agreement without such consent to potential investors or other financing sources
on the condition that such entities or persons agree to keep such terms
confidential for the same time periods and to the same extent as such Party is
required to keep such terms confidential. The Parties agree that all press
releases related to the Program shall be issued jointly by GTC and Genzyme and
that the Party preparing any such press release shall provide the other Party
with a draft thereof reasonably in advance of disclosure so as to permit the
other Party to review and comment on such press release.

     10.3.  PUBLICATIONS. Each Party recognizes the mutual interest in obtaining
valid patent protection. Consequently, any Party, its employees or consultants
wishing to make a publication (including any oral disclosure made without
obligation of confidentiality) relating to work performed by such Party as part
of the Program (the "Publishing Party") shall transmit to the other Party (the
"Reviewing Party") a copy of the proposed written publication at least
forty-five

                                       33
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(45) days prior to submission for publication, or an abstract of such oral
disclosure at least fifteen (15) days prior to submission of the abstract or the
oral disclosure, whichever is earlier. The Reviewing Party shall have the right
to (a) request a delay in publication or presentation in order to protect
patentable information, (b) propose modifications to the publication for patent
reasons or (c) request that the information be maintained as a trade secret.

     If the Reviewing Party requests a delay as described in clause (a) above,
the Publishing Party shall delay submission or presentation of the publication
for a period of ninety (90) days to enable patent applications protecting each
Party's rights in such information to be filed. Upon the expiration of
forty-five (45) days, in the case of proposed written disclosures, or fifteen
(15) days, in the case of an abstract of proposed oral disclosures, from
transmission of such proposed disclosures to the Reviewing Party, the Publishing
Party shall be free to proceed with the written publication or the oral
presentation, respectively, unless the Reviewing Party has requested the delay
described above.

     To the extent possible in the reasonable exercise of its discretion, the
Publishing Party shall incorporate all modifications proposed under clause (b)
above. If a trade secret that is the subject of a request made under clause (c)
above cannot be otherwise protected without unreasonable expense to the
Reviewing Party, such information shall be omitted from the publication.

                   ARTICLE 11. REPRESENTATIONS AND WARRANTIES

     11.1.  AUTHORIZATION. Each Party warrants and represents to the other that
(a) subject to Section 2.3 above, it has the legal right and power to enter into
this Agreement, to extend the rights and licenses granted to the other in this
Agreement, and to perform fully its obligations hereunder, (b) this Agreement is
a valid and binding agreement of such Party, enforceable in accordance with its
terms, (c) such Party has obtained all necessary approvals to the transactions
contemplated hereby and (d) such Party has not made nor will it make any
commitments to others in conflict with or in derogation of such rights or this
Agreement.

     11.2.  INTELLECTUAL PROPERTY RIGHTS.

            11.2.1  GTC hereby represents and warrants that, subject to the
rights held by Centeon as described in Section 2.3 hereof, and as of the Date of
Execution, (a) it possesses an exclusive right, title and interest in or, in the
case of GTC Licensed ATIII Patent Rights, an exclusive license (subject to
certain exceptions set forth in the license covering such Patent Rights) to, the
GTC Patent Rights, the GTC Licensed ATIII Patent Rights and the GTC Technology,
(b) that the GTC Patent Rights and the GTC Technology are free and clear of any
lien or other encumbrance and (c) that it has the right to (i) enter into the
obligations set forth in this Agreement and (ii) grant the rights and licenses
set forth in Article 3 hereof.

            11.2.2  GTC hereby represents and warrants that it is not aware of
any issued patent that would be infringed by the manufacture and sale of
Collaboration Products as contemplated by this Agreement.

            11.2.3  Genzyme hereby represents and warrants that as of the Date
of Execution (a) it possesses an exclusive right, title and interest in the
Genzyme Patent Rights and the

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Genzyme Technology, (b) the Genzyme Patent Rights and the Genzyme Technology are
free and clear of any lien or other encumbrance and (c) it has the right to (i)
enter into the obligations set forth in this Agreement and (ii) grant the rights
and licenses set forth in Article 3 hereof.

     11.3.  WARRANTIES.

            11.3.1  GENZYME WARRANTIES. Genzyme warrants that (i) the
Collaboration Products delivered by Genzyme pursuant to Section 7.2 hereof will
conform in all material respects to the Specifications, the conditions of any
applicable Regulatory Approvals regarding the manufacturing process and any
applicable requirements of the Regulatory Scheme regarding the manufacturing
process and (ii) the Collaboration Products sold pursuant to Section 6.2 hereof
will be marketed and sold in all material respects in accordance with the
conditions of any applicable Regulatory Approvals and any applicable labeling
claims.

            11.3.2  GTC WARRANTIES. GTC warrants that the Collaboration Products
delivered by GTC pursuant to Section 7.2 hereof will conform in all material
respects to the Specifications, the conditions of any applicable Regulatory
Approvals regarding the manufacturing process and any applicable requirements of
the Regulatory Scheme regarding the manufacturing process.

     11.4.  DISCLAIMER OF REPRESENTATIONS AND WARRANTIES. EXCEPT AS OTHERWISE
EXPRESSLY SET FORTH IN THIS AGREEMENT, NONE OF GTC, GENZYME OR ATIII LLC MAKES
ANY REPRESENTATIONS OR EXTENDS ANY WARRANTIES OF ANY KIND, EITHER EXPRESS OR
IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR
A PARTICULAR PURPOSE, AND THE NON-INFRINGEMENT OF ANY THIRD-PARTY PATENTS OR
PROPRIETARY RIGHTS. ALL UNIFORM COMMERCIAL CODE WARRANTIES ARE EXPRESSLY
DISCLAIMED BY THE PARTIES.

     11.5.  LIMITATION OF LIABILITY. It is agreed by the Parties that no Party
shall have a right to or shall claim special, indirect or consequential damages,
including lost profits, for breach of this Agreement. Remedies shall be limited
to claims for amounts due hereunder or as otherwise provided in this Agreement,
including claims for indemnification as provided in Section 12.1 hereof.

                              ARTICLE 12. INDEMNITY

     12.1.  ATIII LLC INDEMNITY OBLIGATIONS. The Operating Agreement shall
provide that ATIII LLC shall indemnify each of the Members and its Affiliates,
employees and agents (each an "INDEMNIFIED PERSON") for any act performed by
such Indemnified Person within the scope of the authority conferred upon such
Indemnified Person under this Agreement; PROVIDED that it shall be a condition
to such indemnity that (a) the Indemnified Person seeking indemnification acted
in good faith and in a manner reasonably believed to be in, or not opposed to,
the best interests of ATIII LLC, (b) the act for which indemnification is sought
did not constitute gross negligence or wilful misconduct by such Indemnified
Person and (c) payment and indemnification of any matter disposed of by a
compromise payment by such Indemnified Person, pursuant to consent decree or
otherwise, shall have been approved by the Members,

                                       35
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which approval shall not be unreasonably withheld or delayed, or by a court of
competent jurisdiction.

     12.2.  INSURANCE. ATIII LLC shall maintain product liability insurance with
respect to development, manufacture and sales of Collaboration Products in an
amount reasonably believed by Genzyme and GTC to be adequate and customary for
the development, manufacture and sale of novel therapeutic products. Genzyme and
GTC shall be named as additional insureds on any such policy.

                        ARTICLE 13. TERM AND TERMINATION

     13.1.  TERM. The term of this Agreement shall be perpetual unless
terminated pursuant to Section 13.2 below.

     13.2.  TERMINATION.  This Agreement may be terminated in the following
circumstances:

            13.2.1  FOR CERTAIN MATERIAL BREACHES. If (a) either GTC or Genzyme
fails to use commercially reasonable and diligent efforts to perform any
material duty imposed upon such Party under this Agreement or a Development
Plan, (b) either GTC or Genzyme fails to make three (3) or more capital
contributions in accordance with Article 4 hereof, or (c) Genzyme fails to use
commercially reasonable and diligent efforts to commercialize any Collaboration
Product in any Major Market Country in accordance with the Commercialization
Plan for such Collaboration Product or meet any of the material due diligence
requirements set forth in any Commercialization Plan and, in any case described
in clauses (a) - (c), such failure to perform is not cured within ninety (90)
days of written notice thereof from the non-breaching Party, the non-breaching
Party may elect, in its sole discretion, to (i) enforce the terms of this
Agreement and seek any and all remedies available to it at law and in equity,
(ii) in the case of clause (b) above, waive the terms of Article 4 hereof with
respect to any one or more required capital contributions and cause the
respective Percentage Interests and future funding responsibilities of the
Parties to be adjusted in accordance with Section 4.1.4 hereof, (iii) in the
case of clause (c) above, cause ATIII LLC to engage a Third Party distributor
for such country in accordance with Section 6.7 hereof or (iv) terminate this
Agreement with the consequences set forth in Section 13.3 below. Such 90-day
period shall be extended to one hundred eighty (180) days if the breaching Party
has engaged in good faith efforts to remedy such default within such 90-day
period and indicated in writing to the non-breaching Party prior to the
expiration of such 90-day period that it believes that it will be able to remedy
the default within such 180-day period, but such extension shall apply only so
long as the breaching Party is engaging in good faith efforts to remedy such
default.

            13.2.2  FOR FAILURE TO MAKE A MILESTONE PAYMENT. In the event that
Genzyme fails to make a milestone payment pursuant to Section 4.4 hereof and
such failure is not cured within sixty (60) days of written notice thereof from
GTC, GTC may elect, in its sole discretion, to either (a) enforce the terms of
this Agreement and seek any and all remedies available to it at law and in
equity or (b) terminate this Agreement with the consequences set forth in
Section 13.3 below.

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<Page>

            13.2.3  FOR CONVENIENCE. Either GTC or Genzyme may elect to
terminate this Agreement for any reason at any time after the earlier of (i)
such time as ATIII LLC has received U.S. FDA approval for the BLA for the first
Collaboration Product or (ii) March 31, 2001 if ATIII LLC has not received U.S.
FDA approval of the BLA for the first Collaboration Product on or before such
date upon one (1) year prior written notice to the other Party (during which
one-year period the obligations of the Parties, including without limitation
obligations with respect to capital contributions, shall continue in full force
and effect).

            13.2.4  UPON BANKRUPTCY. Either GTC or Genzyme may terminate this
Agreement with the consequences set forth in Section 13.3 below upon the
bankruptcy, insolvency, dissolution or winding-up of the other Party, except in
the case of a petition in bankruptcy filed involuntarily against a Party, if
such petition is dismissed within sixty (60) days of the date of its filing.

     13.3.  EFFECTS OF TERMINATION.

            13.3.1  FOR CERTAIN MATERIAL BREACHES. In addition to the rights and
duties set forth in Sections 13.4 and 13.5 below, GTC and Genzyme shall have the
following rights and duties upon termination of this Agreement pursuant to
Section 13.2.1(iv) above:

                    (a)  the non-breaching Party shall obtain from the breaching
Party the irrevocable right and license, with the right to grant sublicenses,
under the breaching Party's Patent Rights, Technology and Manufacturing Know-How
to develop, make, have made, use, offer for sale, sell, have sold, import and
export Collaboration Products in the Field and in the Territory, and the
breaching Party shall execute such documents and take all action as may be
necessary or desirable to affect the foregoing; PROVIDED; that such license
shall be for the same level of exclusivity as the rights granted with respect
thereto under Section 3.1 hereof; PROVIDED FURTHER that any license granted
hereunder shall be subject to the obligation of the non-breaching Party to use
commercially reasonable and diligent efforts to develop and market Collaboration
Products pursuant to such license;

                    (b)  the breaching Party shall assign and transfer all of
its interest in ATIII LLC to the non-breaching Party, and the non-breaching
Party may dissolve ATIII LLC in its sole discretion;

                    (c)  (i) all licenses granted pursuant to Article 3 shall be
revoked, (ii) if ATIII LLC is dissolved, any applicable Regulatory Approvals
(other than any Regulatory Approvals filed in the name of an entity other than
ATIII LLC pursuant to Section 5.3 hereof) and clinical data owned or licensed by
ATIII LLC and any trademarks owned or licensed by ATIII LLC (other than any
trademarks registered in the name of an entity other than ATIII LLC pursuant to
Section 9.1.2 hereof) shall be assigned or licensed to the non-breaching Party
and (iii) any Regulatory Approvals filed and any trademarks registered in the
name of an entity other than ATIII LLC shall be (A) exclusively licensed to
ATIII LLC, the non- breaching Party or any Third Party or Affiliate designated
by such Party until such time as ATIII LLC, the non-breaching Party or its
designee is qualified to hold such Regulatory Approvals or trademarks under the
applicable provisions of the Regulatory Scheme and (B) transferred or assigned
to

                                       37
<Page>

ATIII LLC, the non-breaching Party or its designee, as appropriate, as soon as
practicable thereafter;

                    (d)  the non-breaching Party shall become obligated to pay
the breaching Party an amount equal to eighty percent (80%) of the Fair Value
(as defined in Section 13.3.5 below) of the breaching Party's interest in the
Collaboration Products as of the date of termination, plus interest thereon at
the Base Rate of interest declared from time to time by The First National Bank
of Boston in Boston, Massachusetts from the date of termination to the date
payment is made (the "BREACH BUYOUT AMOUNT"), payable as follows:

                         (1)  if the non-breaching Party elects to sell or
otherwise dispose of all or any portion of its or its Affiliates' right, title
and interest in the Collaboration Products, then the non-breaching Party shall,
upon any such sale or other disposition, pay the breaching Party an amount equal
to seventy-five percent (75%) of the net proceeds of such sale or other
disposition when such payments are actually paid;

                         (2)  for as long as the non-breaching Party has not
sold or otherwise disposed of all or a portion of its right, title and interest
in the Collaboration Products which is equal to or greater than the breaching
Party's Percentage Interest as of the date of termination, the non-breaching
Party shall pay the breaching Party a percentage of Net Profits, which
percentage shall equal (i) the breaching Party's Percentage Interest as of the
date of termination minus (ii) a percentage equal to the portion of the right,
title and interest in the Collaboration Products sold or otherwise disposed of
by the non-breaching Party as described in the preceding paragraph; and

                         (3)  on the fourth anniversary of the date of
termination, the non- breaching Party shall pay the breaching Party the
difference between the aggregate amounts paid pursuant to clauses (1) and (2)
above and the Breach Buyout Amount;

PROVIDED, that the aggregate amount of all payments made under clauses (1), (2)
and (3) shall not exceed the Breach Buyout Amount; and

                    (e)  if Genzyme has not paid all of the payments described
in Section 4.4 hereof on or before the date of termination, termination of this
Agreement shall not relieve Genzyme of its obligations to pay any such unpaid
amount at such time as it becomes due and payable in accordance with the
schedule set forth in Section 4.4 hereof.

            13.3.2  FOR FAILURE TO MAKE A MILESTONE PAYMENT. In addition to the
rights and duties set forth in Sections 13.4 and 13.5 below, GTC shall have the
following rights and duties upon termination of this Agreement pursuant to
Section 13.2.2(b) above:

                    (a)  GTC shall obtain from Genzyme the irrevocable right and
license, with the right to grant sublicenses, under the Genzyme's Patent Rights,
Technology and Manufacturing Know-How to develop, make, have made, use, offer
for sale, sell, have sold, import and export Collaboration Products in the Field
and in the Territory, and Genzyme shall execute such documents and take all
action as may be necessary or desirable to affect the foregoing; PROVIDED, that
such license shall be for the same level of exclusivity as the rights granted
with respect thereto under Section 3.1; PROVIDED FURTHER that any license
granted

                                       38
<Page>

hereunder shall be subject to the obligation of GTC to use commercially
reasonable and diligent efforts to develop and market Collaboration Products
pursuant to such license;

                    (b)  Genzyme shall assign and transfer all of its interest
in ATIII LLC to GTC, and GTC may dissolve ATIII LLC in its sole discretion;

                    (c)  (i) all licenses granted pursuant to Article 3 shall be
revoked, (ii) if ATIII LLC is dissolved, any applicable Regulatory Approvals
(other than any Regulatory Approvals filed in the name of an entity other than
ATIII LLC pursuant to Section 5.3 hereof) and clinical data owned or licensed by
ATIII LLC and any trademarks owned or licensed by ATIII LLC (other than any
trademarks registered in the name of an entity other than ATIII LLC pursuant to
Section 9.1.2 hereof) shall be assigned or licensed to GTC and (iii) any
Regulatory Approvals filed and any trademarks registered in the name of an
entity other than ATIII LLC shall be (A) exclusively licensed to ATIII LLC, GTC
or any Third Party or Affiliate designated by GTC until such time as ATIII LLC,
GTC or its designee is qualified to hold such Regulatory Approvals or trademarks
under the applicable provisions of the Regulatory Scheme and (B) transferred or
assigned to ATIII LLC, GTC or its designee, as appropriate, as soon as
practicable thereafter; and

                    (d)  GTC shall become obligated to pay Genzyme an amount
equal to eighty percent (80%) of the Fair Value (as defined in Section 13.3.5
below) of Genzyme's interest in the Collaboration Products as of the date of
termination, plus interest thereon at the Base Rate of interest declared from
time to time by The First National Bank of Boston in Boston, Massachusetts from
the date of termination to the date payment is made (the "MILESTONE BREACH
BUYOUT AMOUNT"), payable on the terms and conditions and in accordance with the
schedule of payments set forth in Section 13.3.1(d), MUTATIS MUTANDIS.

            13.3.3  FOR CONVENIENCE. In addition to the rights and duties set
forth in Sections 13.4 and 13.5 below, GTC and Genzyme shall have the following
rights and duties upon termination of this Agreement pursuant to Section 13.2.3
above:

                    (a)  the non-terminating Party shall have an option
exercisable upon written notice to the terminating Party within the one-year
period provided in Section 13.2.3 hereof to obtain from the terminating Party
the irrevocable right and license, with the right to grant sublicenses, under
the terminating Party's Patent Rights, Technology and Manufacturing Know-How to
develop, make, have made, use, offer for sale, sell, have sold, import and
export Collaboration Products in the Field and in the Territory, and the
terminating Party shall execute such documents and take all action as may be
necessary or desirable to affect the foregoing; PROVIDED, that such license
shall be for the same level of exclusivity as the rights granted with respect
thereto under Section 3.1; PROVIDED FURTHER that any license granted hereunder
shall be subject to the obligation of the non-terminating Party to use
commercially reasonable and diligent efforts to develop and market Collaboration
Products pursuant to such license;

                    (b)  upon exercise of its license option provided in
paragraph (a) of this Section 13.3.3, the terminating Party shall assign and
transfer all of its interest in ATIII LLC to the non-terminating Party, and the
non-terminating Party may dissolve ATIII LLC in its sole discretion;

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<Page>

                    (c)  upon exercise of its license option provided in
paragraph (a) of this Section 13.3.3, (i) all licenses granted pursuant to
Article 3 shall be revoked, (ii) if ATIII LLC is dissolved, any applicable
Regulatory Approvals (other than any Regulatory Approvals filed in the name of
an entity other than ATIII LLC pursuant to Section 5.3 hereof) and clinical data
owned or licensed by ATIII LLC and any trademarks owned or licensed by ATIII LLC
(other than any trademarks registered in the name of an entity other than ATIII
LLC pursuant to Section 9.1.2 hereof) shall be assigned to the non-terminating
Party and (iii) any Regulatory Approvals filed and any trademarks registered in
the name of an entity other than ATIII LLC shall be (A) exclusively licensed to
ATIII LLC, the non-terminating Party or any Third Party or Affiliate designated
by such Party until such time as ATIII LLC, the non- terminating Party or its
designee is qualified to hold such Regulatory Approvals or trademarks under the
applicable provisions of the Regulatory Scheme and (B) transferred or assigned
to ATIII LLC, the non-terminating Party or its designee, as appropriate, as soon
as practicable thereafter;

                    (d)  upon the exercise of its license option provided in
paragraph (a) of this Section 13.3.3, the non-terminating Party shall become
obligated to pay to the terminating Party an amount equal to one hundred percent
(100%) of the Fair Value (as defined in Section 13.3.5 below) of the terminating
Party's interest in the Collaboration Products as of the date of termination
plus interest thereon at the Base Rate of interest declared from time to time by
The First National Bank of Boston in Boston, Massachusetts from the date of
termination to the date payment is made (the "CONVENIENCE BUYOUT AMOUNT"),
payable on the terms and conditions and in accordance with the schedule of
payments set forth in Section 13.3.1(d), MUTATIS MUTANDIS;

                    (e)  if the license option provided in paragraph (a) of this
Section 13.3.3 is not exercised, then all right, title and interest in the
Collaboration Products shall be sold to the highest bidder within eighteen (18)
months from the date of termination and the proceeds shall be allocated between
the Members in proportion to their Percentage Interests in ATIII LLC as of the
date of termination and ATIII LLC shall be dissolved; and

                    (f)  if Genzyme has not paid all of the payments described
in Section 4.4 hereof on or before the date of termination, termination of this
Agreement shall not relieve Genzyme of its obligations to pay any such unpaid
amount at such time as it becomes due and payable in accordance with the
schedule set forth in Section 4.4 hereof.

            13.3.4  UPON BANKRUPTCY. In addition to the rights and duties set
forth in Sections 13.4 and 13.5 below, GTC and Genzyme shall have the following
rights and duties upon termination of this Agreement pursuant to Section 13.2.4
above:

                    (a)  the terminating Party shall obtain from the
non-terminating Party the irrevocable right and license, with the right to grant
sublicenses, under the non-terminating Party's Patent Rights, Technology and
Manufacturing Know-How to develop, make, have made, use, offer for sale, sell,
have sold, import and export Collaboration Products in the Field and in the
Territory, and the non-terminating Party shall execute such documents and take
all action as may be necessary or desirable to affect the foregoing; PROVIDED,
that such license shall be for the same level of exclusivity as the rights
granted with respect thereto under Section 3.1 hereof; PROVIDED FURTHER that any
license granted hereunder shall be subject to the obligation of the

                                       40
<Page>

terminating Party to use commercially reasonable and diligent efforts to develop
and market Collaboration Products pursuant to such license;

                    (b)  the non-terminating Party shall assign and transfer all
of its interest in ATIII LLC to the terminating Party, and the terminating Party
may dissolve ATIII LLC in its sole discretion;

                    (c)  (i) all licenses granted to Article 3 shall be revoked,
(ii) if ATIII LLC is dissolved, any applicable Regulatory Approvals (other than
any Regulatory Approvals filed in the name of an entity other than ATIII LLC
pursuant to Section 5.3 hereof) and clinical data owned or licensed by ATIII LLC
and any trademarks owned or licensed by ATIII LLC (other than any trademarks
registered in the name of an entity other than ATIII LLC pursuant to Section
9.1.2 hereof) shall be assigned or licensed to the terminating Party and (iii)
any Regulatory Approvals filed and any trademarks registered in the name of an
entity other than ATIII LLC shall be (A) exclusively licensed to ATIII LLC the
terminating Party or any Third Party or Affiliate designated by such Party until
such time as ATIII LLC, the terminating Party or its designee is qualified to
hold such Regulatory Approvals or trademarks under the applicable provisions of
the Regulatory Scheme and (B) transferred or assigned to ATIII LLC, the
terminating Party or its designee, as appropriate, as soon as practicable
thereafter;

                    (d)  the terminating Party shall become obligated to pay to
the non-terminating Party an amount equal to one hundred percent (100%) of the
Fair Value (as defined in Section 13.3.5 below) of the non-terminating Party's
interest in the Collaboration Products as of the date of termination, plus
interest thereon at the Base Rate of interest declared from time to time by The
First National Bank of Boston in Boston, Massachusetts from the date of
termination to the date payment is made (the "BANKRUPTCY BUYOUT AMOUNT"),
payable on the terms and conditions and in accordance with the schedule of
payments set forth in Section 13.3.1(d), MUTATIS MUTANDIS; and

                    (e)  if Genzyme has not paid all of the payments described
in Section 4.4 hereof on or before the date of termination, termination of this
Agreement shall not relieve Genzyme of its obligations to pay any such unpaid
amount at such time as it becomes due and payable in accordance with the
schedule set forth in Section 4.4 hereof.

            13.3.5  FAIR VALUE. For purposes of this Section 13.3, the "FAIR
VALUE" of a Party's interest in the Collaboration Products shall be the amount
an informed and willing buyer under no compulsion to buy would be willing to pay
and an informed and willing seller under no compulsion to sell would be willing
to accept for all right, title and interest in the Collaboration Products,
determined as of the date of termination, which determination shall be made by
the mutual agreement of GTC and Genzyme. In the event that GTC and Genzyme are
unable to agree upon the Fair Value within one hundred and twenty (120) days of
the date of termination, the Fair Value shall be determined by an investment
banking firm selected by mutual agreement of GTC and Genzyme, and the costs and
expenses incurred in connection with the engagement of such investment banking
firm shall be shared equally by GTC and Genzyme.

     13.4.  INVENTORY. Upon the termination of this Agreement, if Genzyme does
not obtain a license pursuant to Section 13.3 hereof, GTC shall have the option
to repurchase Genzyme's

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inventory of Collaboration Products acquired by Genzyme pursuant to Article 6
hereof. Within ten (10) days after such termination, GTC shall elect in writing
to either (a) permit Genzyme to sell off its remaining inventory of
Collaboration Products, PROVIDED that Genzyme shall comply with all of the terms
and conditions of this Agreement restricting such selling activities as in
effect immediately prior to such termination, or (b) repurchase Genzyme's
inventory of Collaboration Products. If GTC fails to make such an election,
Genzyme shall be permitted to sell-off its remaining inventory of Collaboration
Products in accordance with clause (a) of this Section 13.4. Any repurchase of
Genzyme's inventory of Collaboration Products shall be at the price as stated in
Genzyme's then-current price list, LESS a handling charge to be reasonably
determined by the Parties in good faith.

     13.5.  SURVIVAL OF RIGHTS AND DUTIES. No termination of this Agreement
shall eliminate any rights or duties of the Parties accrued prior to such
termination. The provisions of Articles 1, 10 and 12 and Sections 2.2, 2.3, 2.4
(the second paragraph thereof only), 3.3, 4.3, 4.5, 9.1.1, 9.1.3, 9.3, 9.5,
13.3, 13.4, 13.5, 14.1, 14.3, 14.4, 14.5, 14.9, 14.10, 14.11 and 14.12 hereof
shall survive any termination of this Agreement.

                            ARTICLE 14. MISCELLANEOUS

     14.1.  COOPERATION. If either GTC or Genzyme (the "ASSUMING PARTY") shall
assume the Program rights from the other Party (the "RESPONSIBLE PARTY") in
accordance with the provisions of Article 13 hereof, the Responsible Party shall
promptly provide to the Assuming Party (or any Third Party or Affiliate
designated by the Assuming Party) all Technology, Manufacturing Know-How and
access to regulatory filings sufficient to allow the Assuming Party to perform
the duties assumed. The Responsible Party shall further use its best efforts to
provide all assistance required by the Assuming Party with respect to such
transfer so as to permit the Assuming Party to begin to perform such duties as
soon as possible to minimize any disruption in the continuity of supply or
marketing of Collaboration Products. In addition, if upon the date this
Agreement is terminated Collaboration Products are being manufactured in
facilities owned or leased by the Responsible Party (including facilities
subleased by ATIII LLC from the Responsible Party), the Responsible Party agrees
to lease such facilities to the Assuming Party on commercially reasonable terms
for a period of up to twenty-four (24) months.

     14.2.  EXCHANGE CONTROLS. All payments due hereunder shall be paid in
United States dollars. If at any time legal restrictions prevent the prompt
remittance of part or all payments with respect to any country in which
Collaboration Products are sold, payment shall be made through such lawful means
or methods as the Parties may determine in good faith.

     14.3.  WITHHOLDING TAXES. If applicable laws or regulations require that
taxes be withheld from payments made hereunder, the Party paying such taxes will
(a) deduct such taxes, (b) timely pay such taxes to the proper authority and (c)
send written evidence of payment to the Party from whom such taxes were withheld
within sixty (60) days after payment. Each Party will assist the other Party or
Parties in claiming tax refunds, deductions or credits at such other Party's
request and will cooperate to minimize the withholding tax, if available, under
various treaties applicable to any payment made hereunder.

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     14.4.  IRS TRANSFER PRICING ADJUSTMENTS. In the event that the Internal
Revenue Service or any local or state tax authority determines that amounts paid
to GTC or Genzyme by any Party for services performed in connection with the
Program are insufficient and adjusts the revenue reported by Genzyme or GTC
accordingly, then (i) in the case of any payment made by ATIII LLC to Genzyme or
GTC, the amount of the corresponding tax deduction available to ATIII LLC shall
be allocated to Genzyme or GTC, as the case may be, and (ii) in the case of any
payment by GTC or Genzyme to the other, the Party who made such payment shall
promptly pay Genzyme or GTC, as the case may be, an amount equal to the taxes
payable on the additional revenue attributed to such Party plus any interest
expense thereon, which amount shall be grossed-up for taxes payable on the
amount of such payment.

     14.5.  INTEREST ON LATE PAYMENTS. Any payments to be made hereunder that
are not paid on or before the date such payments are due under this Agreement
shall bear interest, to the extent permitted by applicable law, at the Base Rate
of interest declared from time to time by The First National Bank of Boston in
Boston, Massachusetts, calculated on the number of days payment is delinquent.

     14.6.  FORCE MAJEURE. Neither Party shall be held liable or responsible to
the other Party nor be deemed to have defaulted under or breached this Agreement
for failure or delay in fulfilling or performing any term of this Agreement when
such failure or delay is caused by or results from causes beyond the reasonable
control of the affected Party, including without limitation to contamination or
diseases affecting the herd of Transgenic Animals from which tgATIII is
produced, fire, floods, embargoes, war, acts of war (whether war is declared or
not), insurrections, riots, civil commotions, strikes, lockouts or other labor
disturbances, acts of God or acts, omissions or delays in acting by any
governmental authority or the other Party; PROVIDED, HOWEVER, that the Party so
affected shall use commercially reasonable and diligent efforts to avoid or
remove such causes of non-performance, and shall continue performance hereunder
with reasonable dispatch wherever such causes are removed. Each Party shall
provide the other Parties with prompt written notice of any delay or failure to
perform that occurs by reason of FORCE MAJEURE. The Parties shall mutually seek
a resolution of the delay or the failure to perform in good faith.

     14.7.  ASSIGNMENT. This Agreement may not be assigned or otherwise
transferred by any Party without the consent of the other Parties; PROVIDED,
HOWEVER, that either GTC or Genzyme may, without such consent, assign its rights
and obligations under this Agreement (a) in connection with a corporate
reorganization, to any member of an affiliated group, all or substantially all
of the equity interest of which is owned and controlled by such Party or its
direct or indirect parent corporation or (b) in connection with a merger,
consolidation or sale of substantially all of such Party's assets to an
unrelated Third Party; PROVIDED, HOWEVER, that such Party's rights and
obligations under this Agreement shall be assumed by its successor in interest
in any such transaction and shall not be transferred separate from all or
substantially all of its other business assets, including without limitation
those business assets that are the subject of this Agreement. Any permitted
assignee shall assume all obligations of its assignor under this Agreement. Any
purported assignment in violation of this Section 14.7 shall be void.

     14.8.  SEVERABILITY. Each Party hereby agrees that it does not intend to
violate any public policy, statutory or common laws, rules, regulations, treaty
or decision of any government

                                       43
<Page>

agency or executive body thereof of any country or community or association of
countries. Should one or more provisions of this Agreement be or become invalid,
the Parties hereto shall substitute, by mutual consent, valid provisions for
such invalid provisions which valid provisions in their economic effect are
sufficiently similar to the invalid provisions that it can be reasonably assumed
that the Parties would have entered into this Agreement with such valid
provisions. In case such valid provisions cannot be agreed upon, the invalidity
of one or several provisions of this Agreement shall not affect the validity of
this Agreement as a whole, unless the invalid provisions are of such essential
importance to this Agreement that it is to be reasonably assumed that the
Parties would not have entered into this Agreement without the invalid
provisions.

     14.9.  NOTICES. Any consent, notice or report required or permitted to be
given or made under this Agreement by one of the Parties hereto to the other
shall be in writing, delivered personally or by facsimile (and promptly
confirmed by personal delivery or courier), by a next business day delivery
service of a nationally recognized overnight courier service or by courier,
postage prepaid (where applicable), addressed to such other Party at its address
indicated below, or to such other address as the addressee shall have last
furnished in writing to the addressor in accordance with this Section 14.9 and
shall be effective upon receipt by the addressee.

     If to GTC:            Genzyme Transgenics Corporation
                           Five Mountain Road
                           Framingham, Massachusetts 01701
                           Attention:   President
                           Facsimile:   (508) 370-3797

     with a copy to:       Genzyme Transgenics Corporation
                           Five Mountain Road
                           Framingham, Massachusetts 01701
                           Attention:   General Counsel
                           Facsimile:   (508) 370-3797

     If to Genzyme:        Genzyme Corporation
                           One Kendall Square
                           Cambridge, Massachusetts 02139
                           Attention:   President
                           Facsimile:   (617) 374-7423

     with a copy to:       Genzyme Corporation
                           One Kendall Square
                           Cambridge, Massachusetts 02139
                           Attention:   Chief Legal Officer
                           Facsimile:   (617) 252-7553

     If to ATIII           ATIII LLC
     LLC (if               c/o Genzyme Corporation
     such notice is        One Kendall Square
     sent by GTC):         Cambridge, Massachusetts 02139
                           Attention:   President

                                       44
<Page>

                           Facsimile:   (617) 374-7423

     with a copy to:       Genzyme Corporation
                           One Kendall Square
                           Cambridge, Massachusetts 02139
                           Attention:   Chief Legal Officer
                           Facsimile:   (617) 252-7553

     If to ATIII           ATIII LLC
     LLC (if               Genzyme Transgenics Corporation
     such notice is sent   Five Mountain Road
     by Genzyme):          Framingham, Massachusetts 01701
                           Attention:   President
                           Facsimile:   (508) 370-3797

     with a copy to:       Genzyme Transgenics Corporation
                           Five Mountain Road
                           Framingham, Massachusetts 01701
                           Attention:   General Counsel
                           Facsimile:   (508) 370-3797

     14.10. APPLICABLE LAW. This Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Massachusetts without regard to
any choice of law principle that would dictate the application of the laws of
another jurisdiction.

     14.11. ARBITRATION. Any disputes arising between the Parties relating to,
arising out of or in any way connected with this Agreement or any term or
condition hereof, or the performance by either Party of its obligations
hereunder, whether before or after termination of this Agreement (a "DISPUTE"),
which has not resolved in accordance with the provisions of Section 8.3 hereof,
shall be finally resolved by binding arbitration as herein provided.

            14.11.1 GENERAL. Except as otherwise provided in this Section 14.11,
any arbitration hereunder shall be conducted under the commercial rules of the
American Arbitration Association. Each such arbitration shall be conducted in
the English language by a panel of three (3) arbitrators (the "ARBITRATION
PANEL"). Each of GTC and Genzyme shall appoint one (1) arbitrator to the
Arbitration Panel and the third arbitrator shall be appointed by the two (2)
arbitrators appointed by GTC and Genzyme. The Arbitration Panel shall be
convened upon delivery of the Notice of Arbitration (as herein defined). Any
such arbitration shall be held in Boston, Massachusetts. The Arbitration Panel
shall have the authority to grant specific performance, and to allocate between
the Parties the costs of arbitration in such equitable manner as it shall
determine. Judgment upon the award so rendered may be entered in any court
having jurisdiction or application may be made to such court for judicial
acceptance of any award and an order of enforcement, as the case may be.

            14.11.2 PROCEDURE.

                                       45
<Page>

                    (a)  Whenever a Party (the "CLAIMANT") shall decide to
institute arbitration proceedings, it shall give written notice to that effect
(the "NOTICE OF ARBITRATION") to the other Party (the "RESPONDENT"). The Notice
of Arbitration shall set forth in detail the nature of the Dispute, the facts
upon which the Claimant relies and the issues to be arbitrated (collectively,
the "ARBITRATION ISSUES"). Within fifteen (15) days of its receipt of the Notice
of Arbitration, the Respondent shall send the Claimant and the Arbitration Panel
a written Response (the "RESPONSE"). The Response shall set forth in detail the
facts upon which the Respondent relies. In addition, the Response shall contain
all counterclaims which the Respondent may have against the Claimant which are
within the Arbitration Issues, whether or not such claims have previously been
identified. If the Response sets forth a counterclaim, the Claimant may, within
fifteen (15) days of the receipt of the Response, deliver to the Respondent and
the Arbitration Panel a rejoinder answering such counterclaim.

                    (b)  Within fifteen (15) days after the later of (i) the
expiration of the period provided in Section 14.11.2(a) above for the Claimant
to deliver a rejoinder or (ii) the completion of any discovery proceedings
authorized by the Arbitration Panel: (A) the Claimant shall send to the
Arbitration Panel a proposed resolution of the Arbitration Issues and a proposed
resolution of any counterclaims set forth in the Response, including without
limitation the amount of monetary damages, if any, or other relief sought (the
"CLAIMANT'S PROPOSAL"); and (B) the Respondent shall send to the Arbitration
Panel a proposed resolution of the Arbitration Issues, a proposed resolution of
any counterclaims set forth in the Response and a proposed resolution of any
rejoinder submitted by the Claimant, including without limitation the amount of
monetary damages, if any, or other relief sought (the "RESPONDENT'S PROPOSAL").
Once both the Claimant's Proposal and the Respondent's Proposal have been
submitted, the Arbitration Panel shall deliver to each Party a copy of the other
Party's proposal.

                    (c)  The Arbitration Panel shall issue an opinion with
respect to any Dispute, which opinion shall explicitly accept either the
Claimant's Proposal or the Respondent's Proposal in its entirety (the "FINAL
DECISION"). The Arbitration Panel shall not have the authority to reach a Final
Decision that provides remedies or requires payments other than those set forth
in the Claimant's Proposal or the Respondent's Proposal. The concurrence of two
(2) arbitrators shall be sufficient for the entry of a Final Decision. The
arbitrators shall issue a Final Decision within one (1) month from the later of
(i) the last day for submission of proposals under Section 14.11.2(b) above or
(ii) the date of the final hearing on any Dispute held by the Arbitration Panel.
A Final Decision shall be binding on both Parties.

     14.12. INJUNCTIVE RELIEF. The Parties hereby acknowledge that a breach of
their respective obligations under Article 10 hereof may cause irreparable harm
and that the remedy or remedies at law for any such breach may be inadequate.
The Parties hereby agree that, in the event of any such breach, in addition to
all other available remedies hereunder, the non- breaching Party or Parties
shall have the right to obtain equitable relief to enforce Article 10 hereof.

     14.13. ENTIRE AGREEMENT. This Agreement and the Operating Agreement contain
the entire understanding of the Parties with respect to the subject matter
hereof. All express or implied agreements and understandings, either oral or
written, heretofore made are expressly merged in and made a part of this
Agreement. This Agreement supersedes the Convertible Debt

                                       46
<Page>

Agreement. It is understood that the Amended and Restated Convertible Debt
Agreement dated as of September 4, 1997 by and between GTC and Genzyme shall
remain in full force and effect. This Agreement may be amended, or any term
hereof modified, only by a written instrument duly executed by both Parties
hereto. Each of the Parties hereby acknowledges that this Agreement and the
Operating Agreement are both the result of mutual negotiation and therefore any
ambiguity in their respective terms shall not be construed against the drafting
Party.

     14.14. HEADINGS. The captions to the several Articles and Sections hereof
are not a part of this Agreement, but are merely guides or labels to assist in
locating and reading the several Articles and Sections hereof.

     14.15. INDEPENDENT CONTRACTORS. It is expressly agreed that GTC and Genzyme
shall be independent contractors and that, except as Members of ATIII LLC, the
relationship between the two Parties shall not constitute a partnership, joint
venture or agency. Neither GTC nor Genzyme shall have the authority to make any
statements, representations or commitments of any kind, or to take any action,
which shall be binding on the other, without the prior consent of the other
Party to do so.

     14.16. WAIVER. Except as expressly provided herein, the waiver by either
Party hereto of any right hereunder or of any failure to perform or any breach
by the other Party shall not be deemed a waiver of any other right hereunder or
of any other failure to perform or breach by said other Party, whether of a
similar nature or otherwise, nor shall any singular or partial exercise of such
right preclude any further exercise thereof or the exercise of any other such
right.

     14.17. COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

                [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

                                       47
<Page>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first set forth above.

                           GENZYME CORPORATION


                           By: /s/ Peter Wirth
                              --------------------------------------------------

                           Title: Executive Vice President
                                 -----------------------------------------------

                           Date: December 29, 1997
                                ------------------------------------------------


                           GENZYME TRANSGENICS CORPORATION


                           By: /s/ John B. Green
                              --------------------------------------------------

                           Title: Vice President and CFO
                                 -----------------------------------------------

                           Date: December 29, 1997
                                ------------------------------------------------


                           ATIII LLC


                           By:   GENZYME CORPORATION

                           By: /s/ Peter Wirth
                              --------------------------------------------------

                           Title: Executive Vice President
                                 -----------------------------------------------

                           Date: December 29, 1997
                                ------------------------------------------------


                           By:   GENZYME TRANSGENICS CORPORATION


                           By: /s/ John B. Green
                              --------------------------------------------------

                           Title: Vice President and CFO
                                 -----------------------------------------------

                           Date: December 29, 1997
                                ------------------------------------------------

                                       48
<Page>

                                                                   Schedule 1.21

                              GENZYME PATENT RIGHTS

<Table>
<Caption>
             Title                                      Country
             -----                                      -------
<S>  <C>                                      <C>
1.   [****(*)]                                [****(*)]

2.   "Protein Purification"                   U.S. Patent 5,179,199
                                              Australia 79930/87
                                              Canada 549,607
</Table>


----------
* Confidential Treatment has been requested for the marked portion.

                                       49
<Page>

                                                                   Schedule 1.25

                        GTC LICENSED ATIII PATENT RIGHTS

1.   [****(*)];

2.   U.S. Patent Nos. 4,517,294 and 4,632,981;

3.   [****(*)]; and

related applications worldwide (excluding the SMIG Territory).


----------
* Confidential Treatment has been requested for the marked portion.

                                       50
<Page>

                                                                   Schedule 1.26

                                GTC PATENT RIGHTS

<Table>
<Caption>
                                          Application Serial No.
              Title of Patent             or Patent Number                 Territory
--------------------------------------------------------------------------------------------
<S>  <C>                                  <C>                              <C>
1.   Transgenic Animals Secreting         [****(*)]                        [****(*)]
     Desired Proteins in Milk
                                          Patent No.  0264166              Europe

                                          [****(*)]                        [****(*)]
--------------------------------------------------------------------------------------------
2.   [****(*)]                            [****(*)]                        [****(*)]
--------------------------------------------------------------------------------------------
3.   [****(*)]                            [****(*)]                        [****(*)]
--------------------------------------------------------------------------------------------
4.   Expression of Protein in Milk        Patent No, 4,873,316             U.S.
     (licensed from Biogen)
                                          Patent No. 347,431               Europe
--------------------------------------------------------------------------------------------
5.   DNA Sequences to Target              Patent No. 5,304,489             U.S.
     Proteins to the Mammary Gland
     for Efficient Secretion (Licensed    Patent No. 5,565,362             U.S.
     from Pharming)
                                          [****(*)]                        [****(*)]
--------------------------------------------------------------------------------------------
6.   [****(*)]                            [****(*)]                        [****(*)]
--------------------------------------------------------------------------------------------
</Table>


----------
* Confidential Treatment has been requested for the marked portion.

                                       51
<Page>

                                                                  Schedule 3.1.3

                         THIRD PARTY ROYALTIES AND FEES

1.   Patent Sublicense Agreement dated February 1, 1990 by and between DNX, Inc.
     ("Chrysalis") and GTC (as successor to Genzyme).

2.   Agreement dated September 29, 1990 by and among GTC (as successor to
     Genzyme), SMIG and Centeon (as successor to Behring).

3.   License Agreement dated December 26, 1990 by and between Pharming B.V. (as
     successor to Biogen, Inc.) and GTC (as successor to Genzyme).

4.   Cooperation Agreement dated September 6, 1988 by and between Tufts
     University School of Veterinary Medicine and GTC (as successor to Genzyme,
     the successor to Integrated Genetics, Inc.) as amended through and
     including September 6, 1997.

                                       52