EXHIBIT 10.4
-------------

MULTI-PROJECT COLLABORATION AGREEMENT

between

THE PROCTER & GAMBLE COMPANY

and

REGENERON PHARMACEUTICALS, INC.

May 13, 1997

Execution Copy

MULTI-PROJECT COLLABORATION AGREEMENT

I. Definitions
II. Scope; Management Committee
III. Research and Development
IV. Marketing of Products
V. License Grants
VI. Royalties and Accounting
VII. Patents and Infringement
VIII. Confidentiality
IX. Representations, Warranties and Indemnification
X. Term, Termination, Change of Control
XI. Miscellaneous
XII. Execution

MULTI-PROJECT COLLABORATION AGREEMENT

Made as of this 13th day of May, 1997, by and among:

The Procter & Gamble Company, an Ohio corporation having its principal
offices at One Procter & Gamble Plaza, Cincinnati, Ohio 45202 (hereinafter,
together with its Affiliate Procter & Gamble Pharmaceuticals, Inc., "Procter &
Gamble"), and

Regeneron Pharmaceuticals, Inc., a New York corporation having its
principal office at 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707
(hereinafter, together with its Affiliates, "Regeneron").

The following sets forth the background for this Agreement:

Procter & Gamble conducts research and develops and markets pharmaceutical
products for the treatment of a variety of disorders, including without
limitation products having utility in the treatment of bone disorders,
skeletal muscle disorders, cardiac muscle disorders, and antiinfectives.

Regeneron conducts research for the development and commercialization of
pharmaceutical products, based on significant expertise in identifying and
developing molecular receptor targets and compounds that mediate a variety
of disorders. Regeneron has entered into collaborative agreements with
third parties for the research, development and commercialization of
products regarding several such targets identified by Regeneron. Regeneron
is independently pursuing research on other such targets.

Regeneron and Procter & Gamble entered into an agreement on the 11th day of
December 1996, establishing a collaborative effort to perform research and
develop and market products for the prevention, diagnosis, and treatment of
skeletal muscle disorders.

Procter & Gamble and Regeneron share a common vision for further
collaboration, and want to pursue additional research, development and
marketing of products based on other targets and/or compounds identified by
Regeneron.

Procter & Gamble and Regeneron intend fully to utilize their capabilities,
capitalize on each other's expertise, and put forth commercially reasonable
efforts to achieve this objective, and recognize that each party is
contributing valuable technologies and capabilities to this effort and that
the combination of these compatible and complementary technologies and
capabilities creates the basis for a successful collaboration.

Procter & Gamble and Regeneron have also entered into a Securities Purchase
Agreement, Registration Rights Agreement and Warrant Agreement as of the
date first written above as part of this collaboration.

Accordingly, the Parties agree to the following terms and conditions:

Article I - Definitions
-----------------------

1.1. "Affiliate" means any entity that directly or indirectly Owns, is
Owned by, or is under common Ownership with a Party to this Agreement. In no
event will Amgen-Regeneron Partners, any legal entity that Regeneron forms with
Glaxo that relates to their July 1993 agreement, any legal entity that Regeneron
forms with Pharmacopeia, Inc. that relates to their October 1996 agreement, or
any legal entity that Regeneron forms with Procter & Gamble that relates to this
Agreement be deemed to be an Affiliate of Regeneron under this Agreement. "Owns"
or "Ownership" means direct or indirect possession of more than fifty percent
(50%) of the votes of holders of a corporation's voting securities or a
comparable equity interest in any other type of entity.

1.2. "Agreement" means the present agreement together with all attachments.

1.3. "Allowable Research Expense" means Direct Costs incurred by either
Party after June 30, 2002 pursuant to an approved Research Collaboration Plan.
Allowable Research Expenses will be recognized in accordance with GAAP.

1.4. "Allowable Product Expense" means Direct Costs incurred by either
Party pursuant to an approved Product Plan. Allowable Product Expenses will be
recognized in accordance with GAAP.

1.5. "Article" means any article of this Agreement.

1.6. "Commercially Reasonable Efforts" means efforts and resources commonly
used in the research-based pharmaceutical industry for a compound or product at
a similar stage of research, development or commercialization, and having
similar market potential. Commercially Reasonable Efforts shall be determined
taking into account the stage of research, development or commercialization of
the compound or product, the cost-effectiveness of efforts or resources while
optimizing profitability, the competitiveness of alternative products that are
or expected to be in the relevant marketplace, the proprietary position of the
product, the regulatory and business environment, the likelihood of regulatory
approval and product reimbursement, the profitability of the product, the
existence of alternative products that may also be developed by the Parties, and
all other relevant factors. Commercially Reasonable Efforts shall be determined
on a compound-by-compound and market-by-market basis, and it is anticipated that
the level of

effort will change over time reflecting changes in the status of the compound,
product and the market involved.

1.7. "Competing Product" means any compound, product, method or system that
is indicated for the same disease state and has the same mechanism of action as
a Development Compound or Marketed Compound. Competing Product shall not
include Excluded Technology.

1.8. "Compound" means a chemical entity, which is not Excluded Technology,
with research or commercial utility for methods of research, diagnosis,
treatment or prevention of any disease or disorder in humans or animals, and
which

(a) is conceived and/or reduced to practice by Regeneron, or acquired
by Regeneron from a Third Party with the right to sublicense, before or
during the Research Term; or

(b) is conceived and/or reduced to practice by Procter & Gamble, or
acquired by Procter & Gamble from a Third Party with the right to
sublicense, as a direct result from research on a Target during the
Research Term; or

Compound includes Research Compounds, Development Compounds and Marketed
Compounds that may be useful in methods of research, diagnosis, treatment or
prevention of any disease or disorder in humans or animals. Each Compound shall
also be deemed to include all indications, formulations, line extensions, or
modes of administration thereof.

1.9. "Development Compound" means a Compound designated by the Operations
Committee for further development pursuant to Section 3.3(b).

1.10. "Direct Costs" means costs, of a nature, amount, and method of
calculation approved by the Operations Committee via the Research Collaboration
Plan and/or Product Plan, that are incurred by either Party , based upon
efforts, funds and/or resources expended to perform its obligations under such
plan. Direct Costs may include costs associated with activities performed by a
Party, or by a Third Party under an appropriate agreement pursuant to Section
2.6, for the research, development or marketing of Compounds. Direct Costs shall
not include any mark-up or profit above actual costs.

1.11. "Effective Date" means the date described in Section 10.1(a).

1.12. "Excluded Research Project" means a Regeneron research project that
has been excluded from the collaboration of the Parties under this Agreement
pursuant to Section 2.10 or Section 3.2(c).

1.13. "Excluded Technology" means any invention, trade secret or other
information, whether tangible or intangible, whether or not patentable, that is:

(a) conceived or reduced to practice by Regeneron, or acquired from a
Third Party by Regeneron before or during the Term insofar as such
invention, trade secret or other information (i) is part of the subject
matter listed in Attachment 1.13, or (ii) directly relates to an Excluded
Research Project ("Regeneron Excluded Technology"); or

(b) conceived or reduced to practice by Procter & Gamble or acquired
by Procter & Gamble from a Third Party before or during the Term insofar as
such invention, trade secret and other information is not Procter & Gamble
Technology. Notwithstanding the foregoing, Excluded Technology shall not
include any compound, product, method or system which is in human clinical
development or Marketed and is acquired by Procter & Gamble from a Third
Party which, at the time of acquisition is indicated for the same disease
state and is known to have the same mechanism of action as a Development
Compound or Marketed Compound.

1.14. "Fiscal Quarter" means each period of three (3) months ending on 31
March or 30 June or 30 September or 31 December.

1.15. "Fiscal Year" means the twelve (12) month period of time from July 1
to June 30, except that the first Fiscal Year commences on the Effective Date
and ends on June 30, 1998 and the last Fiscal Year during the Research Term
shall end on the anniversary of the Effective Date in the Fiscal Year in which
the Research Term expires or is terminated pursuant to Sections 10.1 and 10.2.

1.16. "FTE" or "Full Time Equivalent" means one Effort Year of an employee
or class of employees. "Effort Year" means nineteen hundred and fifty (1,950)
hours of direct effort expended on approved activities during a Fiscal Year.

1.17. "GAAP" means generally accepted accounting principles.

1.18. "J-V" means such collaborative relationship as may be established
pursuant to Section 3.7 of this Agreement. J-V may or may not be structured as a
separate legal entity, such as a corporation, partnership, LLC, or such other
form as the Parties may agree. In agreeing on the form of the collaborative
relationship, the Parties shall take appropriate account of, among other
factors, ease of administration and tax liabilities.

1.19. "Know-how" means the entire right, title and interest in trade secret
technology. "P&G Know-how" shall mean the entire right, title and interest in
Know-how owned solely or jointly by Procter & Gamble with a Third Party or with
Regeneron pursuant to Section 5.1. "Regeneron Know-how" shall mean the entire
right, title and interest in Know-how owned solely or jointly by Regeneron with
a Third Party or with Procter & Gamble pursuant to Section 5.1.

1.20. "Lead Compound" means a Research Compound that has been demonstrated
to meet Success Criteria, whether or not the Research Compound has been
designated a Development Compound pursuant to Section 3.3(b).

1.21. "Major Country" means the **********.

1.22. "Major Decision" means the following decisions to be made by the
Operations Committee:

(a) Approval of all long-range strategic plans developed pursuant to
this Agreement, including without limitation the Research Collaboration
Plan and the Product Plan;

(b) Disposition of any interest in any type of intellectual property
in which the Parties have rights under this Agreement(other than routine
copyright transfers incident to publications made pursuant to Section 8.3),
including without limitation any license, assignment, or registration of
any Patent, trademark or Know-how;

(d) Expenditure of any funds, or incurrence of any obligation, in
excess of ********* for the acquisition of a particular piece of property
(including without limitation real or intellectual property), equipment or
service regarding work under this Agreement, unless such expenditure or
obligation is explicitly authorized in a Research Project Plan or a Product
approved by the Operations Committee;

(e) Expenditure of any funds, or incurrence of any obligation,
regarding any budget item that cannot be resolved by Program Committee;

(f) Initiation or settlement of any lawsuits by or against the Parties
(except against each other) in connection with this Agreement, subject to
Section 9.3;

(g) Acceptance of contracts outside the ordinary course of business of
the collaboration as described in Section 2.1 and any contracts with either
Party or its Affiliates or any contracts pertaining to the collaboration in
which a Party has a beneficial interest;

(h) Selection of any trademark regarding a Development Compound or
Marketed Compound; and

(i) Initiation of any recalls of Marketed Compounds.

1.23. "Marketed Compound" means a Compound which is sold pursuant to this
Agreement in any country in the Territory.

1.24. "Muscle Field" means the diagnosis, prevention and/or treatment of
conditions in humans and animals associated with the promotion or protection of
skeletal muscle mass or function (including, without limitation, the diagnosis,
treatment or prevention of muscle atrophy), as set forth in the Collaboration
Agreement between the Parties dated the 11th day of December, 1996.

1.25. "Net Sales" means total gross realization less: (i) discounts,
including cash discounts and discounts for special purchases, rebates,
retroactive price reductions or allowances granted or incurred from the billed
amount, (ii) any sales or value added taxes or any other taxes measured by the
amount of sales or gross receipts, and (iii) credits or allowances actually
granted upon claims, rejections or returns, including recalls, regardless of the
party requesting such. As used herein, total gross realization means the list
price for a product containing a Compound multiplied by the volume in units for
units sold or otherwise transferred by either Party or an authorized agent of
either Party to a customer, but excludes sales or transfers between and among
the Parties, the Parties' Affiliates, or an authorized agent or licensee of
either Party, unless such sale or other transfer is to a customer.

1.26. "Operations Committee" or "OC" means the committee described in
Article II.

1.27. "Opting Out Party" means the Party that Opts Out of those research,
development and/or marketing activities with respect to a Compound as specified
in Sections 2.10, 3.2(b), 3.2(c), 3.4(b), 3.6, and 10.3(b). "Opts Out" means
that the Opting Out Party either decides not to

continue with such activities or does not fund its share of Allowable Research
Expenses and/or Allowable Product Expenses with respect to such activities.

1.28. "Party" means Regeneron or Procter & Gamble.

1.29. "Patent" means the entire right, title and interest in a Valid Claim
in a patent application, and all continuing and divisional patent applications,
continuations-in-part, reissue applications and all other related patent
applications claiming priority, indirectly and directly, to such application,
and all patents issuing therefrom, worldwide. "P&G Patent Rights" shall mean the
entire right, title and interest in a Patent owned solely by Procter & Gamble or
jointly by Procter & Gamble with a Third Party or with Regeneron pursuant to
Section 5.1. "Regeneron Patent Rights" shall mean the entire right, title and
interest in a Patent owned solely by Regeneron or jointly by Regeneron with a
Third Party or with Procter & Gamble pursuant to Section 5.1.

1.30. "Proceeding Party" means the Party that is not an Opting Out Party
with respect to a Research Project, or the development or marketing of a
Compound either in the entire Territory or in one or more specific countries
therein.

1.31. "Procter & Gamble Technology" means any invention, Know-how or other
information, other than Compounds which have not met Success Criteria, whether
tangible or intangible, whether or not patentable, which has actual or potential
utility for the identification, research or commercialization of products for
the prevention, diagnosis, or treatment of diseases or disorders in humans or
animals, and which:

(a) has utility in ***** and which, prior to or during the Research

Term, is conceived or reduced to practice by Procter & Gamble or acquired
or licensed by Procter & Gamble from a Third Party with the right to
sublicense; or

(b) does not have utility in ***** and which, during the Research
Term, is conceived or reduced to practice by Procter & Gamble or acquired
or licensed by Procter & Gamble from a Third Party with the right to
sublicense, as a direct result of research on a Target; or

(c) other than (a) and (b), insofar as is necessary for performing
research pursuant to a Research Collaboration Plan using a Procter & Gamble
Target as defined in 1.44(b) and which, prior to or during the Research
Term, is conceived or reduced to practice by Procter & Gamble or acquired
or licensed by Procter & Gamble from a Third Party with the right to
sublicense; or

(d) during the Term, but after the Research Term, is conceived or
reduced to practice by Procter & Gamble or licensed by Procter & Gamble
from a Third Party with the right to sublicense, regarding a Development
Compound or Marketed Compound.

Procter & Gamble Technology may include, without limitation, research
methods and materials (including without limitation genetic materials,
receptors, cell lines and transgenic animals) useful in performing research,
Lead Compounds, formulations, chemical synthesis and manufacturing processes,
methods of diagnosis and methods of treatment.

1.32. "Product Plan" means the annual compilation of objectives,
activities, resource allocations, Success Criteria, Allowable Product Expenses
and budgets regarding the development and/or marketing of Development Compounds
and/or Marketed Compounds agreed to by the OC, as more thoroughly described in
Section 3.3(b).

1.33. "Program Committee" or "PC" means the committee established pursuant
to Section 2.2(b).

1.34. "Regeneron Technology" means any invention, Know-how or other
information, whether tangible or intangible, whether or not patentable, which:

(a) is not Regeneron Excluded Technology, and

(b) is conceived or reduced to practice by Regeneron or acquired or
licensed by Regeneron from a Third Party with the right to sublicense,

(i) before or during the Research Term; or
(ii) after the Research Term, but during the Term, regarding a
Development Compound or Marketed Compound.

Regeneron Technology may include, without limitation, research methods and
materials (including without limitation genetic materials, receptors, cell lines

and transgenic animals) useful in performing research, Targets, Compounds,
formulations, chemical synthesis and manufacturing processes, methods of
diagnosis and methods of treatment.

1.35. "Research Collaboration Plan" means, on a Fiscal Year basis, the
compilation of objectives, prioritization of Research Projects and work on new
areas of research, Success Criteria and overall budget for work by the Parties
during the Research Term, but not including development and/or marketing
activities. After June 30, 2002, the Research Collaboration Plan shall also
include Allowable Research Expenses.

1.36. "Research Compound" means a Compound that has not yet been designated
a Development Compound.

1.37. "Research Project" shall mean research conducted by the Parties for
the purpose of identifying, optimizing, and testing a specific Target, Validated
Target and/or Research Compound.

1.38. "Research Project Plan" shall mean, on a Fiscal Year basis, the
compilation of activities, milestones, budget, and Success Criteria relating to
a Research Project.

1.39. "Research Term" means the period of time beginning on the Effective
Date and unless terminated earlier pursuant to Section 10.2 or 10.3(b), ending
ten (10) years after the Effective Date.

1.40. "Royalty Term" means the period from the first Net Sales in the first
country to the final payment of royalties in the last country pursuant to
Section 6.1.

1.41. "Section" means any section of this Agreement.

1.42. "Success Criteria" means the specific criteria set forth in a
Research Project Plan and Research Collaboration Plan and approved by the OC
that define the minimum technical and commercial requirements for a Research
Compound to be designated a Development Compound.

1.43. "Sumitomo Compound" means any Compound which:
(a) is claimed by a Regeneron Patent;
(b) is owned by Regeneron prior to the Effective Date, or conceived
and solely reduced to practice solely by Regeneron during the Research
Term; and
(c) Sumitomo Chemical Company Limited or its affiliates exercise
rights pursuant to its Technology Development Agreement with Regeneron
executed in March 1989 (hereinafter the "Sumitomo Agreement).

1.44. "Target" means:
(a) any gene, receptor, ligand, or other compound which is Regeneron
Technology, which has actual or potential utility for the identification,
research or

commercialization of compounds for the prevention, diagnosis, or treatment of
diseases or other disorders in humans or animals; or

(b) any gene, receptor, ligand, or other compound which Procter &
Gamble designates as subject to research under this Agreement and Regeneron
agrees to include in a Research Project pursuant to Section 2.1(c) (a "Procter &
Gamble Target").

1.45. "Term" means the period of time specified in Section 10.1(b).

1.46. "Territory" means the entire world, excluding Japan with respect to
any Sumitomo Compound and MuSK and Agrin. Japan shall be included in the
Territory except for Sumitomo Compounds and MuSK and Agrin. "MuSK" shall mean
the materials **********. "Agrin" shall mean the compounds ***********.

1.47. "Third Party" means any entity other than Regeneron or Procter &
Gamble or their Affiliates or a J-V established in accordance with this
Agreement.

1.48. "Valid Claim" shall mean any claim in a published and unexpired
application or patent included within a Patent which claim has not been held
unenforceable, unpatentable or invalid by a decision of a court or other
governmental agency of competent jurisdiction, unappealable or unappealed within
the time allowed for appeal, and which has not been finally abandoned or
admitted to be invalid or unenforceable through disclaimer.

1.49. "Validated Target" means a Target which has been shown to meet all of
the following criteria approved by the PC:
(a) the Target is *******.
(b) agents, ligands, or intracellular molecules that *******; and
(c) the Target is shown to ******.

Article II - Overview and Management of Collaboration
-----------------------------------------------------

2.1. Scope of Collaboration.

(a) The Parties will work together to research, develop and
commercialize Lead Compounds pursuant to this Agreement in the Territory. All
such work shall be conducted pursuant to a Research Collaboration Plan and
Product Plans established by the OC pursuant to Article III. The Parties shall
use Commercially Reasonable Efforts in performing their obligations under this
Agreement.

(b) Work under this Agreement will include work in the Muscle Field,
in addition to other areas of mutual interest. Accordingly, the
Collaboration Agreement dated 11 December 1996 is hereby terminated on the
Effective Date and superseded by the terms of this Agreement.

(c) At Procter & Gamble's sole discretion, Procter & Gamble may
designate genes, receptors, ligands or compounds owned by Procter & Gamble
as a subject of a Research Project. Subject to Regeneron's agreement to
include them as a Research Project, such genes, receptors, ligands or
compounds will be deemed Procter & Gamble Targets. Gene, receptors, ligands
or compounds contributed by Procter & Gamble pursuant to the Collaboration
Agreement specified in Section 2.1(b) shall be deemed Procter & Gamble
Targets.

(d) Subject to the provisions of a Research Project Plan or Research
Collaboration Plan, the primary responsibilities for the activities shall
be as follows:

* Regeneron will identify and characterize Targets and Validated Targets.
Characterization of Procter & Gamble Targets will be the joint responsibility of
the Parties.

* Regeneron will provide Target materials for high throughput screening
(HTS) and will develop low throughput assays. The responsibility for such
activities for Procter & Gamble Targets will be shared.

* Procter & Gamble will develop HTS and combinatorial libraries and conduct
HTS to identify Research Compounds in the collaboration.

* Procter & Gamble will optimize Research Compounds to meet the Success
Criteria. Regeneron will characterize and scale-up peptide and protein Research
Compounds.

* Regeneron will develop and conduct models and assays necessary to assess
Research Compounds against Target success criteria. Procter & Gamble and
Regeneron will share responsibility for developing and using models and assays
to meet success criteria for Procter & Gamble Targets and Targets in the Muscle
Field.

(e) The Parties will also work together to develop and market
Development Compounds and Marketed Compounds in the Territory in accordance
with Product Plans.

2.2. Committee Membership.

(a) OC Membership. The work under this Agreement, as set forth in Section
2.1, shall be performed by the Parties pursuant to the oversight of the OC.
The OC has overall responsibility for the collaboration. The OC may
delegate its responsibilities to

other committees (e.g., to a Program Committee as established pursuant to
Section 2.2(b), or to a Patent Committee, Research Committee, Finance
Committee, Clinical Committee or such other committees as the OC may
establish); however, the OC may not delegate Major Decisions. The OC will
initially consist of two (2) members with one (1) member designated by each
Party. The initial members are listed on Attachment 2.2(a). A chairperson
of the OC will be nominated alternately by Procter & Gamble and Regeneron
to twelve (12) month terms. The Parties will be free to change their
respective representatives, on notice to the other Party. The OC will exist
until the earlier of termination or expiration of this Agreement or when
one Party is an Opting Out Party with respect to all Compounds in all
countries, unless the Parties otherwise agree. The first OC meeting shall
occur within Sixty (60) days of the Effective Date.

(b) PC Membership. A Program Committee is also hereby established and shall
work pursuant to the oversight of the OC. The PC shall develop and propose
the Research Collaboration Plan, as well as a plan for any other Major
Decisions, for the OC's review and approval. Upon the OC's approval of such
Research Collaboration Plan or Major Decision, the PC is responsible for
managing such matters and reporting to the OC on a regular basis. The PC
shall also develop and propose the Research Project Plans. The membership
of the PC shall consist of six (6) members, with three (3) members
designated by each Party. The method for the nomination of the chairperson
of the PC shall be the same as that for the OC as described in Section
2.2(a). The initial members of the PC are listed on Attachment 2.2(b). The
first PC meeting shall occur within thirty (30) days of the Effective Date.

2.3. Meetings. The OC will meet at least one (1) time per Fiscal Year and
the PC will meet at least four (4) times per Fiscal Year, and either or both
committees may meet at additional times as the Parties shall agree. Either Party
may call a special meeting of the OC up to two (2) times per Fiscal Year, on
fifteen (15) days' written notice to the other Party. Additionally, the OC shall
meet within twenty (20) business days of the PC's request to approve any Major
Decisions. The chairperson shall send to all OC or PC members (as the case may
be) notices of all regular meetings and agendas for such meetings. The Party
convening a special meeting shall send notices and agenda for such meeting.
Meetings will alternate between the offices of the Parties, or may be held via
teleconference, videoconference or such other place or manner as the Parties may
mutually agree. Members of the OC and PC shall be empowered to make decisions
within the scope of their respective committee responsibilities and shall have
the right to participate in and vote at meetings in person, by telephone, by
videoconference or by proxy. The Party hosting any meeting shall appoint a
secretary to the meeting who will record the minutes of

the meeting which will be circulated to the members of the OC or PC (as the case
may be) promptly following the meeting for review, comment, and adoption.

2.4. Decision-making Criteria. All decisions of the OC and PC shall be made
by majority vote and in the exercise of good faith. Such decisions shall adhere
to the ethical and legal standards for the research-based pharmaceutical

industry and utilize Commercially Reasonable Efforts to research, develop, and
commercialize Compounds. Notwithstanding the foregoing regarding a majority
vote, Procter & Gamble shall have the tie-breaking vote in the OC and PC with
respect to: (i) any strategic and/or funding/budgeting issues with respect to
the Research Collaboration Plan where Procter & Gamble determines in good faith
that there is the likelihood that Targets proposed by Regeneron may become
Excluded Technology as defined in Section 1.13, (ii) any Third Party costs in
Fiscal Years 1 through 5 which are the responsibility of Procter & Gamble
pursuant to Section 3.2 and (iii) decisions made pursuant to Section 4.1 and
5.4. Regeneron shall have the tie-breaking vote in the OC and PC with respect to
allocating Regeneron research FTEs within the scope of an approved Research
Collaboration Plan.

2.5. Dispute Resolution. Subject to Section 2.4, if a decision cannot be
achieved by the PC, the matter shall be referred to further review and
resolution by the OC. If the OC cannot resolve the matter within thirty (30)
days, the OC shall refer the matter to the Chairman or CEO of Regeneron and the
Group Vice President - Health Care of Procter & Gamble (the "CEOs"), if both
CEOs were not voting members of the OC. If the CEOs (or the OC, if the CEOs are
both voting members) cannot resolve the issue within thirty (30) days, the CEOs
shall mutually agree upon and appoint to the OC a "Temporary Member." "Temporary
Member" means a person who is knowledgeable in the research based pharmaceutical
industry, possessing senior executive experience and skills and not associated
with either Party or a competitor of either Party. If the CEOs cannot mutually
agree on the identity of such Temporary Member within fifteen (15) days of the
end of such thirty (30) day period, the Parties shall request an arbitral panel
composed in accordance with Section 11.4, sitting in Boston, Mass., to, and such
panel shall, appoint to the OC a Temporary Member. The OC shall meet and resolve
the dispute within one week of such appointment of the Temporary Member. All
decisions with respect to the issue in dispute shall be made by majority vote of
the OC. Such Temporary Member shall be appointed to the OC until such time as
the CEOs mutually agree that the dispute or disputes have been resolved or until
one Party is deemed to be an Opting Out Party with respect to such Compound (and
country, if applicable) at issue, whichever is earlier. Such Temporary Member
shall be instructed to render his or her votes consistent with the stated
decision-making criteria of the OC,

as set forth in Section 2.4. The Parties shall share equally in all costs
associated with the appointment of the Temporary Member. Notwithstanding the
foregoing, any disputes, with respect to approving (or not approving) a Research
Collaboration Plan or negotiating a J-V Agreement shall be resolved by the
Temporary Member voting for one Party's proposed Research Collaboration Plan or
J-V Agreement, as the case may be.

2.6. Conduct of Work by Others. It is understood that each Party has
entered into this Agreement based on the specific experience and skill of the
other Party. Accordingly, it is anticipated that work under this Agreement will
be conducted primarily by the Parties. However, it may be commercially
reasonable for the Parties to enter into agreements with commercial or
non-commercial Third Parties to acquire technology or conduct certain aspects of

such work (e.g., because the Third Party's work provides a favorable
cost/benefit vs. utilizing internal resources). Such agreements may include
(without limitation), acquisition of research methods, Compounds or intellectual
property rights (if applicable), consultation, conduct of certain research
tests, chemical synthesis and supply, safety testing, clinical testing, and
marketing support. All such work by or acquisition from Third Parties shall be
conducted pursuant to the Research Collaboration Plan and/or Product Plan and
shall be performed pursuant to written agreements embodying confidentiality,
intellectual property rights and other terms consistent with the terms set forth
in this Agreement. To the extent commercially reasonable, the commercial or
non-commercial Third Parties will be obligated to assign or exclusively license
any patents, patent applications or know-how under terms that are mutually
agreeable to the Parties. Information obtained by a Party from any Third Party
shall be subject to Article VIII of this Agreement. All technology obtained from
a Third Party pursuant to this Section 2.6 shall be, to the extent possible
under commercially reasonable terms, jointly owned by the Parties and shall be
subject to Articles V and VII.

2.7. Record-keeping. All committees shall appoint one Party to keep
complete and accurate records pertaining to the Parties' activities hereunder.
The other Party shall have the right to review such records upon reasonable
notice to the recordkeeping party and at reasonable times. Such records are
subject to audit by the other Party pursuant to Section 6.5 within a reasonable
period after the end of the Fiscal Year. In addition, the recordkeeping party
shall prepare quarterly unaudited financials pertaining to such activities,
which shall be distributed to the Parties within thirty (30) days of the end of
such period.

2.8. Non-compete.

(a) During the Research Term, neither Party will , independently of
the other, perform research regarding a Target or a Research Compound which
is the subject of an approved Research Collaboration Plan.

(b) During the Term, neither Party may directly or indirectly develop
or commercialize a Competing Product in the Territory.

(c) Notwithstanding anything to the contrary contained in this
Agreement, the Parties agree that Excluded Technology is not included
within the scope of this Agreement. In particular, nothing in this
Agreement shall prohibit either Party from performing research, developing
or marketing compounds or products using Excluded Technology.

2.9. Board Representation. Regeneron will uses its best efforts to put a
person representing Procter & Gamble (a "P&G Director") on Regeneron's Board of
Directors sixty (60) days after Regeneron receives written notice from Procter &
Gamble at any time during the Term. The Parties shall work together to identify
a mutually agreeable P&G Director; however, if the Parties cannot agree upon a
P&G Director within thirty (30) days of Regeneron's receipt of Procter &
Gamble's written notice, Procter & Gamble shall designate an officer of Procter

& Gamble as a P&G Director and Regeneron shall uses its best efforts to have
such P&G Director appointed or nominated and elected as a Director on
Regeneron's Board of Directors. Notwithstanding anything to the contrary,
Regeneron shall have no obligation pursuant to this Agreement to take any action
that would result in more than one P&G Director sitting on Regeneron's Board of
Directors at any one time, nor shall Regeneron have any obligations with respect

to appointing or nominating a P&G Director under this Section 2.9 so long as
Procter & Gamble owns less than fifteen percent (15%) of Regeneron's Outstanding
Securities (as defined in the Securities Purchase Agreement).

2.10. Vetoed Project. Procter & Gamble shall have the right to veto a
proposed Research Project ("Vetoed Project") if in good faith it determines that
the Target proposed for the project is a part of an existing Procter & Gamble
program as defined by an internal Procter & Gamble research project proposal and
an approved annual budget. All of Procter & Gamble's ownership rights pursuant
to Section 5.1 to inventions directly related to the Vetoed Project made solely
by Regeneron employees shall revert to Regeneron. All of Regeneron's ownership
rights pursuant to Section 5.1 to inventions directly related to the Vetoed
Project made solely by Procter & Gamble employees shall revert to Procter &
Gamble. Regeneron may not pursue the Vetoed Project during Fiscal Years *****.
At any time after Fiscal Year ***, Regeneron may elect to pursue the Vetoed
Project if, during the twelve (12) months prior to that election, (a)

Regeneron has not Opted Out of research, development or marketing of a
Compound and (b) has not required Procter & Gamble to purchase securities
pursuant to Section 3.5 of the Securities Purchase Agreement. Upon such
election and notice to Procter & Gamble, the Vetoed Project shall be deemed
an Excluded Research Project. If Regeneron makes such an election, then
Regeneron may not require Procter & Gamble to purchase securities pursuant
to Section 3.5 of the Securities Purchase Agreement during the twenty-four
(24) months following the election. In addition, if Regeneron Opts Out of
the research, development or marketing of a Compound during the twenty-four
(24) months following the election, then Regeneron may either (a) terminate
work on the Vetoed Project or (b) have the royalties payable by Procter &
Gamble under Section 6.1 with respect to such Compound shall be reduced by
*****. If Regeneron elects to terminate work on the Vetoed Project, then
the Vetoed Project will be deemed to never have been a Vetoed Project and
the rights to inventions made solely by Regeneron employees or solely by
Procter & Gamble employees directly related to the Vetoed Project shall be
jointly owned by Procter & Gamble and Regeneron as set forth in Section
5.1.

Article III - Research and Development

3.1. Research Collaboration Plan. The Parties will agree to a Research
Collaboration Plan within sixty (60) days after the Effective Date. The OC is
authorized to approve and amend the Research Collaboration Plan. The timing and
calculations for the Research Collaboration Plan budget for Fiscal Year 6 and
beyond are contained in Attachment 3.1. In Fiscal Years 1 through 5, the

Research Collaboration Plan budget shall include FTE allocations and any Third
Party costs.

3.2. Funding of Research Collaboration Plan.

(a) Fiscal Years 1 through 5. During the first five (5) Fiscal Years
of the Research Term, Regeneron shall provide the following number of
Regeneron research FTEs per Fiscal Year for Regeneron's work pursuant to
the Research Collaboration Plan:

Fiscal Year Regeneron FTEs
1 ***
2 ***
3 (JAS, OND '99) ***
3 (JFM, AMJ, '00) ***
4 ***
5 ***

Procter & Gamble may, at its sole discretion, fund an additional *****
Regeneron research FTEs in the last six months of Fiscal Year 3, Fiscal
Year 4 and Fiscal Year 5 ("Option Period") at Procter & Gamble's written
request . Procter & Gamble will give three (3) months' notice to Regeneron
prior to the beginning of such Option Period that it elects to fund such
additional ***** Regeneron research FTEs for the entire Option Period.
While Procter & Gamble funds the additional ***** FTEs during the Option
Period, Regeneron shall also fund and supply ***** additional Regeneron
research FTEs for the entire Option Period. These ***** Regeneron research
FTEs (*** funded by Procter & Gamble, *** funded by Regeneron) during the
Option Period shall initially be devoted to research in the Muscle Field,
but may be assigned to other Research Projects as the Parties may mutually
agree. Procter & Gamble shall make research payments pursuant to Section
3.2(d). All costs associated with work by Procter & Gamble pursuant to the
Research Collaboration Plan shall be borne by Procter & Gamble. In
addition, Procter & Gamble shall pay for all Third Party costs for which it
approves in its sole discretion.

(b) Fiscal Years 6 through 10. If Procter & Gamble and/or Regeneron do
not terminate the Research Term at the end of Fiscal Year 5 pursuant to
Section 10.2, the Parties shall equally fund Allowable Research Expenses
associated with the Research Collaboration Plan for work done after the
fifth (5th) Fiscal Year. Allowable Research Expenses shall include: (i) at
least ***** Regeneron research FTEs at the FTE Rate specified in Section
3.2(d) plus the Inflation Payment Adjustment described in Section 3.2(d);
(ii) no more than ***** Procter & Gamble FTEs, unless there is a
Development Compound in the Muscle Field and in such case, such Procter &
Gamble FTE number shall not exceed ****** Procter & Gamble FTEs, at an FTE
rate(s) agreed by the OC pursuant to the "FTE cost calculation process" set
forth in Attachment 3.1; and (iii) any additional Allowable Research
Expenses. At Regeneron's option during Fiscal Years 6 through 10, Regeneron
may require Procter & Gamble to purchase Regeneron equity pursuant to

Section 3.5 of the Securities Purchase Agreement. Subject to the Parties'
minimum funding commitments pursuant to this Section 3.2(b), either Party
may become an Opting Out Party with respect to specific Research Projects.

(c) Regeneron Proposals to Increase Regeneron FTEs in Fiscal Years
6 - 10. Regeneron may propose increases in Regeneron research FTEs *****
Regeneron research FTEs or more above the Regeneron research FTE threshold
set forth in Section 3.2(b) to the OC, provided that Regeneron has met and
continues to meet its obligations (including without limitation funding
obligations pursuant to this Section 3.2) under this Agreement. However,
Regeneron may not make such proposals if Regeneron is an

Opting Out Party under Section 3.2(b) or has received additional equity
purchases by Procter & Gamble pursuant to Section 3.5 of the Securities
Purchase Agreement. Regeneron must make any such proposal at least *****
months prior to the beginning of Fiscal Year 6, or the beginning of any
subsequent Fiscal Year. Procter & Gamble shall have ***** days from the
time of Regeneron's proposal to the OC to agree to or reject such Regeneron
research FTE increases. If Procter & Gamble rejects such increases, the OC
shall define one or more Excluded Research Projects involving a research
area which has not been the subject of a Research Project Plan in a manner
acceptable to both Parties, and of a scope consistent with the increased
Regeneron research FTEs proposed by Regeneron. If an Excluded Research
Project has been agreed to by the OC, Procter & Gamble will be deemed an
Opting Out Party with respect to any compound resulting from that Excluded
Research Project. Such compound will be considered a "Compound" for
purposes of Sections 5.7 and 6.1.

(d) Regeneron's FTE Rate; Payment. Procter & Gamble's funding will be
made pursuant to Attachment 3.2(d)(1). An additional Inflation Payment
Adjustment shall be made in Fiscal Years 1 through 10 pursuant to
Attachment 3.2(d)(2). Such Inflation Payment Adjustment shall be based on
Regeneron's annual cost per research FTE of ***** ("FTE Rate"). The FTE
Rate includes costs such as those listed in Attachment 3.2(d)(3). The
Inflation Payment Adjustment shall be calculated by multiplying the number
of Regeneron research FTEs per Fiscal Quarter listed in Attachment
3.2(d)(2) by the FTE Rate Adjustment, which is defined as the quarterly
equivalent of the FTE Rate multiplied by the percentage change (rounded to
the nearest tenth of a percent) between the Consumer Price Index for All
Urban Consumers as published by the U.S. Bureau of Labor Statistics ("CPI")
for June 1997 versus the CPI for the month of June immediately preceding
the Fiscal Year in which such payments are applicable. The calculation for
and examples of such Inflation Payment Adjustments are detailed in
Attachment 3.2(d)(2). Regeneron shall use funding provided under this
Section 3.2 solely for carrying out the Research Collaboration Plan.
Regeneron shall submit a report to Procter & Gamble within forty-five (45)
days after the end of each Fiscal Quarter detailing the number of FTEs
performing work pursuant to the Research Collaboration Plan and detailed
description of such work. Regeneron shall submit invoices to Procter &
Gamble pursuant to this Section 3.2(d), including, if applicable, a

calculation of any amounts payable as Inflation Payment Adjustments,
quarterly in arrears. Invoices submitted to Procter & Gamble pursuant to
this Section are payable net thirty (30) days after receipt and are subject
to Procter & Gamble's audit pursuant to Section 6.5.

3.3. Selection of Development Compounds.

(a) The PC or either Party may propose to the OC that a Research
Compound be further developed as a Development Compound, if such Compound
has undergone sufficient testing to demonstrate that it has met the Success
Criteria established pursuant to a Research Project Plan.

(b) If the OC agrees that the Research Compound meets the Success
Criteria, then the Compound shall be designated a Development Compound.
Within ***** days after the designation of a Development Compound by the
OC, the OC shall approve a Product Plan for such Development Compound. The
Product Plan shall include general goals of the Parties relating to the
development and marketing of each Development Compound and the timing,
nature, and priority of resources to be applied and will detail tasks and
goals, personnel allocation, outside services and costs, Success Criteria,
Allowable Product Expenses, budgets, and such other matters deemed
necessary to implement the Product Plan. The Product Plan will include a
spending forecast through the end of clinical trials for the Development
Compound and a budget for the next Fiscal Year that will be updated by the
OC at least annually on a Fiscal Year basis. Procter & Gamble is
responsible for taking the lead in proposing such budget with significant
and timely input from Regeneron. The timing and calculations for the
typical Product Plan budget is contained in Attachment 3.1 as an example.
The OC will have complete authority to adopt all Product Plans.

3.4. Funding of Development Compounds and Marketed Compounds; Opting Out.

(a) Allowable Product Expenses. Allowable Product Expenses for
Development Compounds in the Muscle Field shall be shared equally.
Allowable Product Expenses to support an Investigational New Drug
application (IND) pursuant to 21 C.F.R. ss.312.1 et seq. for Development
Compounds other than those Development Compounds in the Muscle Field in
Fiscal Years 1 through 5 shall be paid by Procter & Gamble; all other
Allowable Product Expenses for such Development Compounds shall be shared
equally. Allowable Product Expenses shall be payable quarterly in arrears,
based on justification of Allowable Product Expenses incurred over the
quarter. Regeneron and Procter & Gamble shall submit reports to each other
within thirty (30) days of the end of each Fiscal Quarter detailing the
number of FTEs performing work pursuant to the Product Plan, Third Party
costs and other costs incurred in research, development and marketing
activities, as well as a detailed description of such work. Each Party
shall review and approve the other Party's reports within fifteen (15) days

thereafter, subject to the OC's approval, if necessary. Procter & Gamble
will then calculate the amount that shall be paid by either Party to the
other Party to equalize funding and so advise Regeneron within seven (7)
days. The Party to whom funds are owed will issue an invoice for the
corresponding amount, payable within thirty (30) days. Costs incurred and
paid pursuant to this Section are subject to audit pursuant to Section 6.5.

(b) After the end of Fiscal Year 5, either Party may become an Opting
Out Party with respect to a Research Project, thereby Opting Out with
respect to all further development and marketing of all Lead Compounds that
result from that Research Project in the Territory. Either Party may, at
any time during the Term, become an Opting Out Party with respect to a
Development Compound or Marketed Compound, either in total or on a
country-by-country basis pursuant to Section 3.6. The Proceeding Party may
proceed to research, develop and/or market such Compound at its own
expense. However, unless the Parties otherwise agree, a Party may not Opt
Out from or otherwise not pay its share of Allowable Research Expenses or
Allowable Product Expenses to which such Party has committed in a Research
Project Plan or Product Plan. The Opting Out Party shall grant licenses to
the Proceeding Party pursuant to Section 5.7. Royalties paid pursuant to
such licenses shall be made pursuant to Article VI.

(c) If both Parties are Opting Out Parties with respect to a
Development Compound or Marketed Compound pursuant to Section 3.4(b), the
OC shall use Commercially Reasonable Efforts to determine the disposition
of the rights to such Compounds.

3.5. Research, Development and Marketing Communication. In addition to
Regeneron's reporting obligations under Section 3.2(d), Regeneron and Procter &
Gamble will submit reports to each other not less than two (2) times per Fiscal
Year presenting a meaningful summary of research, development and marketing
activities performed under this Agreement. Regeneron and Procter & Gamble will
make presentations of such activities to each other, beyond that made to the OC,
as reasonably requested by each other. All technology generated by the Parties
shall be disclosed pursuant to Section 7.1. The Parties shall use their best
efforts to communicate information only within the scope of this Agreement .
Regeneron and Procter & Gamble will also communicate informally and through the
OC to inform each other of research and development done under this Agreement.
Regeneron and Procter & Gamble will provide each other with raw data in original
form or a photocopy thereof for any and all work carried out under this
Agreement as reasonably requested by the other. Any information contained in
such reports and as otherwise communicated by Regeneron or Procter & Gamble is
subject to Article

VIII. If one Party is deemed an Opting Out Party, the Proceeding Party shall
annually report to the Opting Out Party research, development and marketing
activities performed for Compounds in the Territory for the prior Fiscal Year
sufficient to allow the Opting Out Party to determine whether the Proceeding

Party is utilizing Commercially Reasonable Efforts.

3.6. Global Development. The Product Plan shall set forth commercially
reasonable development work (including without limitation clinical studies) to
support acceptable regulatory applications for marketing clearance in all Major
Countries. The costs associated with these activities shall be deemed "Global
Expenses." If either Party fails to pay its share of Global Expenses with
respect to a Compound, such Party shall be deemed an Opting Out Party with
respect to such Compound in the entire Territory pursuant to Section 3.4(b).
Either Party may Opt Out of the commercialization of a Compound on a
country-by-country basis provided it funds its share of total Global Expenses,
to the extent that funding of any development and/or marketing expenses is
solely attributable to one country and is not considered a Global Expense
("Country Expenses"). A Party that does not pay such Country Expenses shall be
deemed an Opting Out Party with respect to such Compound in that particular
country only pursuant to Section 3.4(b).

3.7. J-V Formation. Commencing at the end of the ***** Fiscal Year, the
Parties shall negotiate in good faith an agreement by the end of the *****
Fiscal Year that contains all of the terms and conditions of this Agreement,
along with other terms and conditions as the Parties may agree to develop and/or
market Compounds, including without limitation reasonable non-compete provisions
("J-V Agreement"). In the event that the Parties cannot finalize such J- V
Agreement prior to the end of the ***** Fiscal Year the Parties may commence
dispute resolution pursuant to Section 2.5 or the Parties may terminate this
Agreement pursuant to Section 10.2, elect to continue to perform research,
development and marketing activities pursuant to this Agreement until its
termination, or negotiate such other arrangement as the Parties may agree.

3.8. Sumitomo Compounds.

(a) Regeneron shall, subject to the confidentiality provisions of
Article VIII, have the right to disclose to Sumitomo Chemical Company
Limited and its affiliates (herein "Sumitomo") information regarding a
Compound solely conceived and reduced to practice by Regeneron solely for
the purpose of, and to the extent necessary for, enabling Regeneron to
fulfill its obligations under the Sumitomo Agreement. ****************.

(b) If Sumitomo does not license MuSK and Agrin in accordance with the
Sumitomo Agreement, Regeneron has the right to attempt to license MuSK
and/or Agrin to a Third Party for use, sale, manufacture, distribution, and
marketing solely in Japan. Regeneron shall have the right to provide such
Third Party, solely for the purpose of obtaining such license and subject
to the confidentiality provisions of Article VIII, information about MuSK
and Agrin developed after the Effective Date. *************.

Article IV - Marketing of Products
- -----------------------------------

4.1. Marketing and Sales Strategy. **************** in the OC regarding the

strategy and tactics of marketing and sale of the Marketed Compounds in
accordance with the Product Plan, including without limitation prices of
Marketed Compounds, method of sales and distribution, organization and
management of sales and marketing, packaging and labeling, appointment of
distributors pursuant to Section 4.3 and other terms and conditions for such
sales and marketing. Procter & Gamble shall use Commercially Reasonable Efforts
in making such decisions. That portion of the Product Plan that does not relate
to the sales and marketing strategy (e.g., the annual budget), shall be agreed
to by a majority of the OC.

4.2. Net Profits. The Parties, so long as neither Party is an Opting Out
Party with respect to such Marketed Compound either in the entire Territory or
in one or more specific countries, as appropriate, will share equally in the Net
Profits of each Compound sold. "Net Profits" mean Net Sales less Allowable
Product Expenses.

4.3. Exclusive Distributor. The OC may appoint either Party or a Third
Party to act as its agent in connection with the marketing, sale and
distribution of Marketed Compounds, and the OC and/or the Parties (as the case
may be) shall grant to such agent(s) appropriate authority to perform its or
their responsibilities hereunder. In connection with such marketing, sales and
distribution, the following principles shall apply:

(a) the business objective will be to maximize overall profits; and
(b) in the event that a Third Party is appointed as the Parties' agent
with respect to the marketing, sale and distribution of the Marketed
Compound in a country, Regeneron and Procter & Gamble will each receive
equal shares of any revenue received from such Third Party, so long as
neither Party is an Opting Out Party with respect to such Marketed Compound
in such country.

4.4. Regeneron Co-Promotion Activities. Provided that Regeneron is not an
Opting Out Party with respect to the Compound, Regeneron will have an equal
right and opportunity, but not the obligation, to participate in the sales and
marketing efforts in any country in the Territory as to which it has not Opted
Out by supplying up to fifty percent (50%) of a Marketed Compound's sales and
marketing efforts with notice to Procter & Gamble within ***** days of the OC's
decision to prepare a regulatory application for marketing clearance in the
first Major Country with respect to all Major Countries, then on a
country-by-country basis upon regulatory filings in such countries other than
Major Countries. Regeneron's and Procter & Gamble's sales and marketing
personnel costs shall be an Allowable Product Expense and shall be calculated
for both Parties on the same basis (e.g., the cost per salesperson or sales call
for Regeneron and Procter & Gamble shall be the same per year). If Regeneron
wants to discontinue or decrease its co-promotion activities, it must give
Procter & Gamble ***** months' notice prior to such discontinuation or decrease.
Either Party's choice to not promote a Marketed Compound shall not cause such
Party to be an Opting Out Party with respect to such Marketed Compound, so long
as such Party meets its funding obligations pursuant to Section 3.4.

4.5. Trademarks; Packaging. After a Compound has been designated a
Development Compound, the Parties shall jointly develop a trademark for such
Development Compound. So long as it is not an Opting Out Party with respect to
such Compound in a country, Procter & Gamble shall file, prosecute and maintain
all trademark applications and registrations for such trademarks. Procter &
Gamble shall pay all expenses in connection with filing and prosecution of such
trademarks. All other costs associated with such trademarks shall be deemed
Allowable Product Expenses. As long as neither Party is an Opting Out Party with
respect to the Marketed Compound, such Marketed Compound shall be sold under a
single trademark which shall be owned by Procter & Gamble (and Procter & Gamble
shall grant Regeneron a royalty-free license to such trademark(s) if Regeneron
promotes a Marketed Compound pursuant to Section 4.4) or, if a legal entity is
formed pursuant to a J-V Agreement, the trademark shall be owned by such entity
to the extent legally permissible. If one Party is an Opting Out Party with
respect to such Marketed Compound, any trademarks shall be owned by the
Proceeding Party. So long as neither Party is an Opting Out Party, the label of
the Marketed Compound will contain the name of Regeneron and Procter & Gamble,
to the extent legally permissible.

Article V - License Grants
- --------------------------

5.1. Rights in Technology Developed During Agreement. Patents and Know-how
regarding all inventions, trade secrets and other information, whether tangible
or intangible, whether or not patentable resulting from work by the Parties
under this Agreement shall be owned:

(a) by Procter & Gamble, if such technology is conceived or reduced to
practice solely by employees of Procter & Gamble prior to Fiscal Year 6;

(b) jointly, if such technology is conceived and/or reduced to
practice either solely by employees of Regeneron or jointly by employees of
Procter & Gamble and Regeneron; and

(c) jointly, if such technology is Procter & Gamble Technology
conceived and reduced to practice solely by employees of Procter & Gamble
during Fiscal Years 6 through 10. Inventorship shall be determined
according to the laws of the United States. Filing, prosecution,
maintenance and enforcement of such Patents shall be handled pursuant to
Article VII. Any use of technology owned by a Party under this Section that
is conceived solely by employees of the other Party, other than uses which
have actual or potential utility for the identification, research or
commercialization of products for the prevention, diagnosis, or treatment
of diseases or disorders in humans or animals, shall be subject to a
reasonable royalty to be negotiated. All use of such technology shall also
be subject to Section 2.8.

5.2. License Grants during Research Term.

(a) Procter & Gamble hereby grants Regeneron

a Sole License under P&G Patents and Know-how to Procter & Gamble
Technology conceived and reduced to practice by employees of Procter &
Gamble prior to Fiscal Year 6, or acquired by Procter & Gamble with the
right to sublicense prior to or during the Research Term, to make, have
made, use, import and offer for sale, and sell Lead Compounds and Procter &
Gamble Targets during the Research Term, subject to Section 2.8. The
license shall be royalty free for uses which have actual or potential
utility for the identification, research or commercialization of products
for the prevention, diagnosis, or treatment of diseases or disorders in
humans or animals. For all other uses a reasonable royalty will be
negotiated.

(b) Regeneron hereby grants Procter & Gamble
a Sole License under Regeneron Patents and Regeneron Know-how to make, have
made, use, import, and offer for sale and sell Regeneron Technology which
is (i) conceived or reduced to practice by Regeneron before the Term or
(ii) acquired by Regeneron from a Third Party with the right to sublicense
prior to or during the Research Term, subject to

Section 2.8. The license shall be royalty free for uses which have actual
or potential utility for the identification, research or commercialization
of products for the prevention, diagnosis, or treatment of diseases or
disorders in humans or animals. For all other uses a reasonable royalty
will be negotiated.

(c) The licenses granted in (a) and (b) above will not be used by
either Party independent of this Agreement in research that, will lead to
Competing Products. Any dispute under this Section will be resolved by the
OC.

(d) As used herein, "Sole License" shall mean a non-exclusive license
in the Territory under Know-how or a Patent, without the right to
sublicense, granted by a "Licensor Party" to the other "Licensee Party,"
wherein the Licensor Party shall not grant any Third Party rights under the
Know-how or Patent to the subject matter of the license.

5.3. Rights upon Termination of Research. Except as otherwise directed
pursuant to Section 10.2 or Section 10.3, the Parties shall grant the following
licenses upon expiration of the Research Term.

(a) Procter & Gamble hereby grants Regeneron a non-exclusive license
in the Territory under P&G Patents and Know-how to Procter & Gamble
Technology conceived or reduced to practice by employees of Procter &
Gamble prior to Fiscal Year 6, or acquired by Procter & Gamble with the
right to sublicense prior to or during the Term to make, have made, use,
import and offer for sale, and sell Lead Compounds and Procter & Gamble
Targets.

(b) Regeneron hereby grants Procter & Gamble a non-exclusive license
in the Territory under Regeneron Patents and Regeneron Know-how to make,

have made, use, import, and offer for sale and sell Regeneron Technology
which is (i) conceived or reduced to practice by Regeneron before the Term
or (ii) acquired by Regeneron from a Third Party with the right to
sublicense prior to or during the Term.

(i) royalties will be paid pursuant to Section 6.1 for the
marketing of any Lead Compounds that are not Development Compounds or
Marketed Compounds; and

(ii) a reasonable royalty to be negotiated in good faith will be
paid for all uses other than the identification, research or
commercialization of products for the prevention, diagnosis, or treatment
of diseases or disorders in humans or animals reasonable royalty to be
negotiated for all other uses.

(d)Neither Party shall file an Abbreviated New Drug Application
("ANDA") in the U.S. or an equivalent foreign application for generic
approval for marketing of a Compound using the licenses under this Section.

5.4. Rights on Termination if Milestones are Met. In the event a Party
terminates the Agreement pursuant to Section 10.2, and if ***** Research
Compounds have been determined by Procter & Gamble or the OC to meet their
Success Criteria pursuant to a Research Project Plan by the end of Fiscal Year
5, then:

(a) if Procter & Gamble is the terminating party, then Procter &
Gamble shall grant Regeneron an exclusive, royalty-free license in the
Territory under P&G Patents and P&G Know-how to make, have made, use,
import, offer for sale, and sell Lead Compounds and Validated Targets, and
a non-exclusive, royalty-free license in the Territory under P&G Patents
and P&G Know-how to make, have made, use, import, offer for sale, and sell
other Procter & Gamble Technology; or

(b) if Regeneron is the terminating party, then Regeneron shall grant
Procter & Gamble an exclusive, royalty-free license in the Territory under
Regeneron Patents and Regeneron Know-how to make, have made, use, import,
offer for sale, and sell Lead Compounds and Validated Targets, and a
non-exclusive, royalty-free license in the Territory under Regeneron
Patents and Regeneron Know-how to make, have made, use, import, offer for
sale, and sell other Regeneron Technology.

5.5. Rights in Technology upon Termination Pursuant to Section 10.3(b).

In the event that Procter & Gamble terminates the Agreement pursuant to
Section 10.3(b) then the Parties shall grant the following licenses:

(a) If *** Research Compounds have been determined by Procter & Gamble
or the OC to have met their Success Criteria pursuant to a Research Project

Plan at the time of termination, then Procter & Gamble shall grant
Regeneron an exclusive, royalty-free license in the Territory under P&G
Patents and P&G Know-how to make, have made, use, import, offer for sale,
and sell Lead Compounds and Validated Targets, and a non-exclusive,
royalty-free license in the Territory under P&G Patents and P&G Know-how to
make, have made, use, import, offer for sale, and sell other Procter &
Gamble Technology; or

(b) If Procter & Gamble or the OC have not determined that ***
Compounds have met their Success Criteria pursuant to a Research Project
Plan at the time of termination, then (i) Procter & Gamble shall grant
Regeneron a non-exclusive, royalty free license in the Territory under &G
Patents and Know-how to Lead Compounds and

Procter & Gamble Targets conceived and reduced to practice by Procter &
Gamble, or acquired by Procter & Gamble from a Third Party with the right
to sublicense, during the Term to make, have made, use, import and offer
for sale, and sell Lead Compounds and Procter & Gamble Targets; and (ii)
Regeneron shall grant Procter & Gamble a non-exclusive license,
royalty-free in the Territory under Regeneron Patents and Regeneron
Know-how to make, have made, use, import, and offer for sale and sell
Regeneron Technology which is conceived and reduced to practice by
Regeneron, or acquired by Regeneron from a Third Party with the right to
sublicense during the Term.

5.6. Rights in Compounds under Research, Development and Marketing. Subject
to Section 3.8, a Party shall not grant any license to a Third Party in the
Territory under any Patent or Know-how owned in whole or in part by that Party
to make, have made, use, import or sell any Compound during the Term with
respect to Compounds that are the subject of joint research, development or
marketing by the Parties under this Agreement or a J-V Agreement. The Parties
shall grant licenses under Patents or Know-how to each other, or to any jointly
owned entity as may be established by the Parties pursuant to a J-V Agreement,
as may be necessary to facilitate research, development and/or marketing of such
Compounds in the Territory.

5.7. Grant of License by Opting Out Party. In the event a Party becomes an
Opting Out Party with respect to a Compound in its entirety or on a
country-by-country basis, then the license granted by the Opting Out Party to
the Proceeding Party shall be an exclusive license, with the right to
sublicense, to make, have made, use, import and sell such Compound under the
Patents, Know-how, trademarks and copyrights regarding that Compound owned in
whole or in part by the Opting Out Party. The license shall be in all countries
of the Territory in which Opting Out has been deemed to occur, and shall be
subject to the royalty set forth in Section 6.1. The Opting Out Party shall
comply with reasonable requests for cooperation by the Proceeding Party, and the
Proceeding Party shall reimburse the Opting Out Party for reasonable
out-of-pocket expenses incurred with respect to such cooperation.

Article VI - Royalties and Accounting

6.1. Royalty Calculation.

(a) The Proceeding Party will pay to the Opting Out Party a royalty on
Net Sales of a Marketed Compound on a country-by-country basis, sold by the
Proceeding

Party, its Affiliates, licensees and/or sublicensees in the
Territory at the applicable rate listed below multiplied by the Net Sales
in such country:

Opt Out Time Royalty
------------ -------

Prior to the ***** up to ****%

Upon or after designation as *** but prior to ***%
the *****

Upon or after the ***** but prior to the ***%
**********

Upon or after the*************** ***%

Such royalty will be paid for a period of ***** years from the date of
first sale to a customer of such Compound in a particular country, or for
so long as the manufacture, use, importation or sale of the Compound would,
but for the licenses granted herein, infringe a Valid Claim of a licensed
Patent in such country, whichever is longer.

(b) If the Parties license the Compound to a Third Party pursuant to
Section 3.4(c) *****************. Examples of the respective percentages
are outlined in Attachment 6.1(b). Reasonable out-of-pocket expenses
incurred in obtaining such licensee shall be shared equally by the Parties.
Notwithstanding the above, either Party may receive, without sharing with
the other Party, reimbursement from such licensee for reasonable,
*********** to account for indirect overhead) costs of research,
development and/or marketing costs (whether internal or Third Party) to be
incurred by such Party for work to be conducted in the future on behalf of
the licensee. Any amounts in excess of such reimbursement shall be shared
in the same proportion as calculated above in this Section 6.1(b) All
amounts from licensees received by either Party shall be fully disclosed to
the other Party and subject to audit (including without limitation the
calculation of Fully-Loaded costs) pursuant to Section 6.5.

(c) If the Proceeding Party elects to distribute or sublicense a Compound
in any country, and a license must be obtained from a Third Party to
manufacture and/or market such Compound to avoid a non-frivolous claim of
patent infringement, the Proceeding Party shall offset the following
portion of the Third Party license fee, royalty or other similar payments

("Licensee Fees") against the Opting Out Party's royalty:

********************************
--------------------------------

*** ***
*** ***

Any portion of Licensee Fees paid by the Proceeding Party that is to
be offset against the Opting Out Party's royalty but that exceeds the
Opting Out Party's royalty payable, shall be carried forward and accrue
interest pursuant to Section 6.4 and be offset against future royalties as
such royalties become payable.

6.2. Royalty Payment.

(a) Royalties payable under Section 6.1 will be paid not later than
sixty (60) calendar days following the end of each Fiscal Quarter. All
payments shall be accompanied by a report in writing showing the Fiscal
Quarter for which such payment applies, the amount billed to Third Parties
for Marketed Compounds sold during such Fiscal Quarter, the deductions from
the amount billed to arrive at the Net Sales, the Net Sales for the Fiscal
Quarter, and the royalties due on such Net Sales, such report being broken
down by Marketed Compound and country. All royalties will be paid in the
currency where Net Sales take place or, at the option of the payee, in US
dollars at a rate of exchange on the last business day of the Fiscal
Quarter as quoted in The Wall Street Journal (or Citibank, N.A. if such
rates are not available in The Wall Street Journal).

(b) All royalties due under this Article VI will be deposited in a
bank chosen by the recipient by the date due. Any amounts or royalties
prohibited from export by a particular country will be deposited in a bank
chosen by the recipient in such country. Any deductions for withholding
taxes imposed by the country in which Net Sales take place will be withheld
and paid as required by law. The amount of tax withheld shall be for the
account of the Party receiving the payment. The amount of withholding tax
will be allocated, if applicable, in the ratio of the respective income to
which the withholding tax is related. The paying Party will provide
promptly upon request any receipts from the governmental or taxing
authority evidencing payment of such taxes and will assist the receiving
Party in claiming relief from double taxation.

6.3. Records. Procter & Gamble and Regeneron will maintain, and will
require their Affiliates and sublicensees to maintain, complete and accurate
records of Net Sales of Marketed Compounds sold subject to the royalty
provisions of Section 6.1 and the audit provisions of Section 6.5.

6.4. Interest Rate. Unless otherwise provided in this Agreement, any
payments past due will bear interest at the prime rate (such quoted in The Wall
Street Journal on the first day of the month of the accrual) plus two (2)
percentage points, compounded monthly.

6.5. Audit. Records shall be open for audit during reasonable business
hours for a period of three (3) years from creation of individual records for
examination not more often than once each year by an independent certified
public accountant ("CPA") selected by the payee and reasonably acceptable to the
payer for the sole purpose of verifying the correctness of payments to be made
under this Agreement. If the CPA finds a discrepancy of greater than ten (10)
percent of such payment, the CPA shall submit a detailed report regarding the
audit and such discrepancy to both Parties within thirty (30) days of commencing
the audit. The Parties shall attempt to resolve such discrepancy to their mutual
satisfaction during the next fifteen (15) days. If the Parties cannot resolve
the discrepancy, their CEOs shall meet within ten (10) days after such fifteen
(15) day time period. If the CEOs cannot resolve the dispute within five (5)
days, either Party may take such dispute to arbitration pursuant to Section
11.4. The calculation of such payment shall be deemed final (and not subject to
audit or dispute resolution) five (5) years after the period in which such
payment was due, unless arbitration pursuant to Section 11.4 is commenced prior
to such time. Out-of-pocket expenses incurred with respect to such CPA shall be
paid by the payee; however, the payer shall reimburse the payee for such CPA
expenses if the discrepancy is greater than ten (10%) percent, as such
discrepancy is determined by the CEOs or arbitrators.

Article VII - Patents and Infringement
--------------------------------------

7.1. Disclosure. Procter & Gamble will promptly disclose to Regeneron all
Procter & Gamble Technology described in Section 1.31. Regeneron will promptly
disclose to Procter & Gamble all Regeneron Technology described in Section 1.34
The Parties intend that there be a timely and full exchange of all information
arising from each Research Collaboration Plan or Product Plan subject to the
terms and conditions of this Agreement. Each Party shall promptly disclose to
the other Party any critical data or development which it reasonably believes
would or could have a material effect, whether positive or negative, on a
Research Collaboration Plan or Product Plan.

7.2. Patent Applications. Regeneron and Procter & Gamble will discuss and
evaluate Technology disclosed pursuant to Section 7.1, and confer regarding the
advisability of filing patent applications to cover any Technology. The Party
(herein "Responsible Party") for the

filing, prosecution and maintenance of patent applications shall be: (a) Procter
& Gamble, if the subject invention is made solely by employees of Procter &
Gamble; (b) Regeneron, if the subject invention is made solely by employees of
Regeneron; or (c) determined by agreement of the Parties for all other
inventions, taking into account the nature of the invention and the relationship
of the invention to inventions claimed in other patents or applications.
Regeneron and Procter & Gamble will discuss with each other the advisability of
filing Patent applications beyond the priority country.

7.3. Filing and Prosecution of Patents. The Responsible Party shall, at its
expense, diligently file, prosecute, issue, and maintain patent applications
according to its own internal standards and for effectively covering other
inventions made by its employees or consultants. The Responsible Party will
endeavor to ensure that all patent applications are filed before any public
disclosures so as to ensure validity of patent applications filed outside of the
United States. The Responsible Party will submit a substantially complete draft
of each patent application to the other Party at least thirty (30) days prior to
the contemplated filing date and consider any comments of the other Party,
provided that in those circumstances where the Responsible Party believes time
is of the essence, the Responsible Party will endeavor to provide the other with
such advance notice as it reasonably can under the circumstances. Regeneron and
Procter & Gamble will confer with each other regarding the prosecution of such
Patent Applications and will copy each other with any official action and
submission in such Patent Applications.

7.4. Alternate Responsibility for Prosecution. In the event the Responsible
Party determines that it will not file, prosecute, issue or maintain, a Patent
in a particular country, it shall promptly notify the other Party. The other
Party shall then have the right, but not obligation to assume responsibility for
the Patent, and thereby become the Responsible Party for that Patent pursuant to
Section 7.3. The other Party shall be given all necessary authority by the
original Responsible Party to file, prosecute, issue, and maintain the Patent.

7.5. Infringement. Procter & Gamble and Regeneron shall promptly notify
the other in writing of any infringement of a Patent within the Patent Rights
licensed or to be licensed pursuant to Article V of which they become aware.

7.6. Enforcement of Patents. Regeneron and Procter & Gamble may, but shall
not be required to, prosecute any alleged infringement or threatened
infringement of a Patent within the Patent Rights of which they are aware or
which is brought to their attention. The prosecuting

Party shall act in its own name and at its own expense unless the other Party at
its option pays fifty percent (50%) of all reasonable out-of-pocket costs.
Regeneron and Procter & Gamble shall cooperate fully with each other including,
if required to bring such action, the furnishing of power of attorney. Any
recovery obtained shall belong to the prosecuting Party unless the other Party
has paid fifty percent (50%) of said costs in which case each Party will receive
fifty percent (50%) of any recovery.

7.7. Alternate Responsibility for Enforcement. If Regeneron or Procter &
Gamble has failed to prosecute under Section 7.6 with respect to alleged or
threatened infringement of one of its Patents (i) three (3) months after it has
been notified in writing by the other of such alleged infringement or (ii) one
(1) month before the time limit, if any, set forth in the appropriate laws and
regulations for the filing of such actions, whichever comes first, the other
may, but shall not be required to, prosecute any alleged infringement or
threatened infringement of the Patent. Such prosecuting Party shall act in its
own name and at its own expense. In such event, both Parties shall cooperate
fully with each other at their own expense, including if required in order to
bring such an action, the furnishing of a power of attorney. Any recovery
obtained shall belong to the prosecuting Party.

7.8. Trademark Infringement and Enforcement. Procter & Gamble and Regeneron
shall promptly notify the other in writing of any infringement of a trademark
under Section 4.5 of which they become aware. The owner of the trademark
application or registration may, but shall not be required to, prosecute any
such alleged infringement or threatened infringement. The prosecuting Party
shall act in its own name (unless joinder of the other Party is required by law
in which case it shall be joined) and at its own expense unless the other Party
at its option pays fifty percent (50%) of all reasonable out-of-pocket costs.
Regeneron and Procter & Gamble shall cooperate fully with each other in such
action. Any recovery obtained shall belong to the prosecuting Party unless the
other Party has paid fifty percent (50%) of the costs in which case each Party
will receive fifty percent (50%) of any recovery.

7.9. Alternate Responsibility for Trademark Enforcement. If the owner of
the trademark application or registration has failed to prosecute under Section
7.8 with respect to an alleged or threatened infringement of a trademark (i)
three (3) months after it has been notified in writing by the other of such
alleged infringement or (ii) one (1) month before the time limit, if any, set
forth in the appropriate laws and regulations for the filing of such actions,
whichever comes first, the other Party may, but shall not be required to,
prosecute any alleged infringement or threatened infringement of the trademark.
Such prosecuting Party shall act in its own name

and at its own expense. In such event, both Parties shall cooperate fully with
each other at their own expense. Any recovery obtained shall belong to the
prosecuting Party.

Article VIII - Confidentiality
------------------------------

8.1. Confidentiality and Non-Use Obligations. Each Party shall maintain in
confidence all information (herein "Information") which is:

(a) disclosed to it by the other Party pursuant to Section 7.1;
(b) developed by the Party during the Research Term; or
(c) other information ("Other Information") disclosed by the other

Party which is not within the scope of the collaboration and which is
considered confidential by the other Party, and so designated as
confidential in writing when first disclosed or within thirty (30) days
after disclosure if the first disclosure is oral.
The Party shall take all reasonable precautions to:
(d) prevent disclosure of such Information to Third Parties, except as
set forth in Section 2.6, Section 8.3 and Section 11.10, or as may be
necessary for the filing or prosecution of patent applications pursuant to
Article VII;
(e) use Know-how pursuant to the rights and obligations of the Party
pursuant to Article V; and
(f) use Other Information only for the purposes of this Agreement.
These restrictions upon disclosure and use of Information shall terminate
ten (10) years after the date such Information is developed or disclosed as
set forth above, but shall not apply to any specific portion of Information
which:

(i) is Other Information already in the possession of a Party at
the time of disclosure by the other Party;

(ii) is or later becomes available to the public other than by
default by the Party;

(iii) is received from a Third Party having no obligation of
confidentiality to the other Party;

(iv) is Other Information developed by the Party entirely without
reference or use of Information, as established by probative
documentary evidence; or

(v) is required to be disclosed by law or government regulation.

8.2. Prior Confidentiality Agreements. The "Confidential Disclosure
Agreement" dated February 25, 1997 and the Collaboration Agreement dated
December 11, 1996 between Regeneron Pharmaceuticals, Inc. and Procter & Gamble
have separately been rendered void and all Information to be kept confidential
under such agreements as of the Effective Date will be subject to the terms of
Section 8.1 as if disclosed under this Agreement.

8.3. Research Manuscripts and Abstracts. It is understood the Parties may
wish to publish or otherwise disclose technology to a Third Party for
publication in a reputable scientific forum (for example, as an abstract, poster
presentation, lecture, article, book, or any other means of dissemination to the
public). Either Party may make such a disclosure to a Third Party regarding
preclinical research solely invented by its own employees, provided such Party
has filed a patent application adequately describing and claiming any technology
embodied in such disclosure pursuant to Article VII. If such disclosure is
related to clinical research or work jointly invented by the Parties, no such
disclosure will be made to a Third Party until a patent application has been
filed adequately describing and claiming any patentable technology embodied in

such disclosure pursuant to Article VII and the non-disclosing Party has been
provided thirty (30) days to review and comment on such disclosure. Such
disclosures may be made to a Third Party regarding clinical research only if
clinical data has been locked and if disclosure presents no significant risk to
regulatory filings and serves a compelling business reason for publication. Any
disputes regarding the appropriateness and content of any such disclosure shall
be resolved by the PC.

Article IX - Representations, Warranties and Indemnification
------------------------------------------------------------

9.1. Patents.
(a) Each Party warrants that, as of the Effective Date, it has no
actual knowledge of any information rendering invalid or unenforceable any
Patent licensed to the other Party under Article V or VII. Each Party will
promptly inform the other Party immediately if it obtains such information
after the Effective Date.

(b) Each Party warrants that it is has no actual knowledge of any
patents or Know-how owned by a Third Party that might prevent, inhibit, or
limit the Parties from conducting the research, development and marketing
activities under this Agreement other than what has been previously
disclosed. Each Party warrants that, except as disclosed in Attachment
9.1(b), it has not entered into any agreement with a Third Party that might
prevent, inhibit, or limit the Parties from conducting the research,
development and marketing activities under this Agreement. Regeneron
warrants that Attachments

1.13 and 9.1(b) are complete lists of Excluded Technology and Third Party
Agreements relating to Excluded Technology, respectively, existing as of
the Effective Date.

9.2. No Guarantee. The Parties understand that the research and development
work to be conducted pursuant to this Agreement will involve untested,
experimental, and currently undeveloped technology and that neither Regeneron
nor Procter & Gamble guarantees the safety or usefulness of any Compound. Except
as expressly set forth in this Agreement, the Parties disclaim all warranties of
any nature, express or implied.

9.3. Indemnification.

(a) Indemnification Regarding Joint Activities, General. Any and all
liability, damage, loss, cost (including without limitation reasonable
attorneys' fees) and expense resulting from any suits, claims, actions,
demands, liabilities, expenses and/or loss ("Losses") relating to the joint
development, manufacture, use, storage, distribution or sale of any
Compound ("Joint Activities") will be shared equally. Each Party shall
indemnify and hold harmless the other Party for such Party's respective
share of such liability; provided, however, that the portion of Losses due

to the gross negligence or willful or intentional misconduct of either or
both Party(ies) shall be governed by Section 9.3(b).

(b) Indemnification by the Parties. Each Party shall indemnify and
hold the other Party harmless from and against that portion of any and all
Losses due to the gross negligence or willful or intentional misconduct of
such indemnifying Party, as well as any Losses that were not caused by
Joint Activities.

(c) Indemnification by the Proceeding Party. The Proceeding Party
agrees to save, defend and hold the Opting Out Party harmless from and
against any and all Losses to the extent that such factual allegations
forming the primary basis for such Losses occurred after the Party became
an Opting Out Party with respect to that Compound and/or country. Both
Parties shall provide prompt notice to the other of such potential Losses.
The Proceeding Party shall assume control of the defense of the potential
Losses (including without limitation the right to settle the claim). The
Opting Out Party shall provide reasonable cooperation to the Proceeding
Party, and the Proceeding Party shall reimburse the Opting Out Party its
reasonable out-of-pocket expenses.

(d) Indemnification Procedure. In the event that either Party receives
notice of potential Losses, such Party shall immediately inform the other
Party and the OC. The OC shall decide the manner in which to respond to and
handle the claim. If the OC cannot decide on how to respond to the claim
prior to five (5) days before the answer is

due, the Party receiving the notice shall answer the claim and take
reasonably necessary actions to defend itself, and the other Party may
appoint its own counsel at its own expense, until the OC agrees on how to
handle the claim.

Article X - Term, Termination; Change of Control
------------------------------------------------

10.1. Effective Date and Term.
(a) Effective Date. Within three (3) days of the date first written
above, the Parties shall file the appropriate documents with the U.S.
Federal Trade Commission and the U.S. Department of Justice pursuant to the
Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and
including such Act's enabling regulations (collectively "HSR"). This
Agreement shall become effective upon such date that the applicable HSR
waiting period has expired or is otherwise terminated ("Effective Date").

(b) Term. Unless terminated earlier by mutual agreement or by either
Party pursuant to Sections 10.2 or 10.3 , this Agreement shall commence on
the Effective Date and expire at the later of (i) the end of the Research
Term; (ii) the end of development and marketing of the last Compound to be
developed or marketed (unless such compound is the subject of a separate

agreement); or (iii) the end of the Royalty Term. Rights in technology
shall be as set forth in Section 5.3.

10.2. Termination. Either Party may terminate the Research Term, and may
terminate the Agreement, provided there are no remaining royalty obligations, at
the end of Fiscal Year 5. Such termination may be made following notice to the
other Party delivered prior to the end of Fiscal Year 4. Rights in technology
shall be as set forth in Section 5.3. However, if *** Research Compounds have
been determined by Procter & Gamble or the OC to meet their Success Criteria
pursuant to a Research Project Plan by the end of Fiscal Year 5, then the
terminating Party shall be granted rights pursuant to Section 5.4, and any
license that had been granted to the terminating Party pursuant to Sections 5.6
or 5.7 shall be terminated.

10.3. Default.
(a) General Default. Failure by either Party (the "Defaulting Party")
to comply with any of the material obligations contained in this Agreement,
the Securities Purchase Agreement, the Registration Rights Agreement, the
Warrants Purchase Agreement or any J-V Agreement shall entitle the other
Party (the "Nondefaulting Party") to give to the Defaulting Party notice
specifying the nature of the default and requiring it to cure such default.
If the Defaulting Party disagrees with the existence, extent or nature of
the

default, the Parties shall use good faith efforts to resolve the
dispute within thirty (30) days. If (i) such default is not cured with such
thirty (30) day period after the receipt of such notice or (ii) the Parties
have not otherwise resolved the dispute during such thirty (30) day period,
the Nondefaulting Party shall be entitled to initiate arbitration under
Section 11.4 and at its sole discretion terminate this Agreement. In the
event of such termination, and in addition to any other remedies available
to the Nondefaulting Party, the Defaulting Party shall be deemed an Opting
Out Party with respect to any compounds pursuant to Section 5.7.

(b) Special Default. Regeneron shall promptly notify Procter & Gamble
if any of its Key Executives leaves, or makes a decision to leave the
employment of Regeneron prior to the beginning of Fiscal Year 5. The
"Regeneron Key Executives" are listed in Attachment 10.3(b). Procter &
Gamble may, after the end of a ***** waiting period following such
notification, provide Regeneron with notice of termination, with the
termination to be effective ***** after such notice of termination of the
Agreement. Rights in technology shall be as set forth in Section 5.5.

10.4. Change of Control.
(a) In the event of a Change in Control, as that term is defined in
Section 10.6(a), of either the Parties or their respective Affiliates that
have responsibilities or obligations under this Agreement (each
collectively or individually then referred to as the "Acquired Company")
and the Acquired Company is not an Opting Out Party with respect to all
Compounds in all countries under this Agreement, then the Party affiliated

with the Acquired Company shall notify the other Party of any such Change
in Control as soon as the Change in Control may publicly be announced. Upon
receipt of any such notification, the other Party or an Affiliate thereof
(the "Electing Company") shall have the unilateral right to give notice to
the Acquired Company within ***** days after its next regularly scheduled
board meeting, but in no event longer than ***** days, after receipt of the
Acquired Company's notification that the Electing Company:

(i) elects not to continue the research, development and
marketing collaboration, whether or not a J-V has been formed (the
"Option"), in which case a determination of the License Fee pursuant
to Section 10.7 will be made, and within ***** following such License
Fee determination will make the further election either to purchase
the entire interest of the Party affiliated with the Acquired Company
under this Agreement or any J-V

Agreement ("Acquired Company Interest") or offer the Acquired Company
the option to purchase the entire interest of the Electing Company
under this Agreement or any J-V Agreement ("Electing Company
Interest") at the License Fee (but in the event that the Acquired
Company does not desire to purchase the Electing Company Interest, the
interests of the Parties shall be disposed of by sale, license or
other commercially reasonable arrangement for a price that maximizes
value for both Parties, paid by a Third Party or a Party, and each
Party shall have the right to receive half of the consideration thus
obtained), or

(ii) desires to continue the collaboration for a period of up to
****** from the date of the Change in Control (the "Trial Period")
upon the express condition that the ultimate parent of the entity
acquiring control of the Acquired Company within ***** days thereafter
agrees in writing to such Trial Period and otherwise agrees to be
bound by the provisions of this Agreement, the Registration Rights
Agreement, the Securities Purchase Agreement, Warrant Agreement and
any J-V Agreement. If the ultimate parent of the acquiring entity
accepts these conditions, the collaboration shall continue, and the
Option shall expire unless the Electing Company exercises the Option
within ***** days prior to the expiration of the Trial Period. If the
ultimate parent of the acquiring entity fails to give notice within
the required period that it will be bound by the provisions of such
aforementioned Agreements, the Electing Company shall be deemed to
have exercised the Option as of the expiration of such **** day period
and the Parties shall then follow the procedures set forth in this
Section 10.6.

10.5. Substantial Stock Accumulation. In the event of a Substantial Stock
Accumulation in either the Procter & Gamble Parent or the Regeneron Parent, as
soon as the Party affiliated with the Affected Company has knowledge of the
Substantial Stock Accumulation, it shall give prompt notice to the other Party.
Such notice shall be separate from and in addition to the notice provided for in

Section 10.4 and must be given regardless of whether the Party affiliated with
the Affected Company regards the Substantial Stock Accumulation as being not in
the best interest of the collaboration. From the date on which the Party
affiliated with the Affected Company has notice of the Substantial Stock
Accumulation, the following provisions shall become effective and remain
effective until the Substantial Stock Accumulation is eliminated, unless
otherwise agreed:

(i) If the Party that is not affiliated with the Affected Company
reasonably determines in good faith that the person or entity making
the Substantial Stock Accumulation is a competitor of such Party or
its Affiliates, such Party may so inform the other Party in writing.
Promptly after receipt of such notice, the Party affiliated with the
Affected Company shall establish a

procedure whereby no director or executive employee of the Affected
Company who was not a director or employee of the Affected Company
prior to the Substantial Stock Accumulation, and who was previously a
director or employee of the person or entity making the Substantial
Stock Accumulation (a "Tainted Director or Executive"), shall receive
any of the following: (x) confidential information of the other Party
and its Affiliates; and (y) confidential information of the
collaboration, except that any such Tainted Director or Executive can
be given information as to actual and projected sales and profits of
the collaboration.

(ii) If the Party that is not affiliated with the Affected
Company does not give notice pursuant to this Section 10.5, the Party
affiliated with the Affected Company shall establish a procedure
whereby no Tainted Director or Executive shall receive confidential
information of the other Party and its Affiliates but need not place
any restrictions on confidential or other information of the
collaboration.

(iii) In the event of a material violation of this Section 10.5,
the non- breaching Party may, without resort to the dispute resolution
procedure set forth in Articles II and XI, bring an immediate court
action or enjoin such violation and to recover any damages that it may
have incurred by reasons of such violation.

10.6. Definitions.
(a) For purposes of this Agreement, a "Change in Control" of a company
shall be deemed to have occurred in the event of (i) a merger,
consolidation, reorganization, recapitalization, the purchase of
substantially all of the company's assets, or other transaction in which or
as result of which the common stock of the company, or a successor entity
having the same ownership as the company, shall cease (except temporarily)
to be a publicly traded security; or (ii) the acquisition by any
individual, firm, corporation, or entity (other than any profit sharing or

other employee benefit plan of the company or any Affiliate, or any
employee or group of employees or former officers an/or directors of the
company or its Affiliates) of beneficial ownership, directly or indirectly,
of securities of the company representing more than **** of the combined
voting power of the company's then outstanding voting securities.
Notwithstanding the foregoing, for purposes of this Section 10.6(a), a
Change in Control shall only be deemed to occur for Procter & Gamble if
there is a Change in Control of The Procter & Gamble Company or Procter &
Gamble Pharmaceuticals, Inc.

(b) A "Substantial Stock Accumulation" of a company shall be deemed to
have occurred in the event of the accumulation by any individual, firm,
corporation, or entity (other than any profit sharing or other employee
benefit plan of the company or any

Affiliate, or any employee or group of employees or former officers an/or
directors of the company or its Affiliates) of beneficial ownership,
directly or indirectly, of securities of the company representing more than
***** of the combined voting power of the company's then outstanding voting
securities.

(c) Notwithstanding the foregoing in Sections 10.6(a) and (b), Leonard
Schleifer, M.D., Ph.D., the present President and Chief Executive Officer
of Regeneron, may increase his percentage of Regeneron's or Regeneron's
Parent's combined voting power of its outstanding securities and no
Substantial Stock Accumulation or Change in Control for Regeneron shall be
deemed to have occurred. For the purposes of this Section 10.6(c), Dr.
Schleifer's ownership of securities of Regeneron or Regeneron's Parent
shall be deemed to be his direct or indirect ownership of capital shares or
options to purchase such capital shares of Regeneron or Regeneron's Parent
and the direct or indirect ownership of such shares by members of his
family living in his household to the extent that Dr. Schleifer retains
voting control, the power to exercise such options, and the right to
dispose of such shares, and shall not include any other shares over which
he does not possess Beneficial Ownership, as defined in the Securities and
Exchange Act of 1934, as amended.

10.7. License Fee. The "License Fee" for purposes of Sections 10.4 and 10.5
shall be determined as follows:
(a) License Fee has two components: a Valuation (as defined herein) of
the Parties' interest in the Agreement or J-V Agreement with respect to
Compounds to which neither Party has Opted Out in total and a running
royalty on Net Sales of any Compound for which neither Party has Opted Out,
such rate and term being calculated as per Section 6.1 ("Running Royalty").
Each Party shall designate an investment banking firm of its choice, and
each investment banking firm will be asked to prepare an appraisal as to
the fair market value of the collaboration as a going concern that would be
received in cash from a Third Party if a sale of the collaboration were
made to a Third Party, taking into account any contractual obligation of
either Party or its Affiliates to refrain from manufacturing or marketing a

product competitive with the products in the Territory for any period, the
value of the information, Patents and Know-how, and other assets being
licensed and the potential market for such Compounds in the Territory
("Fair Market Value"). The Fair Market Value shall not include Compounds in
specific countries or in the entire Territory for which either Party is an
Opting Out Party, as such royalty shall continue to be governed pursuant to
Section 6.1, regardless of a Change of Control. *************. The
investment bankers will be asked to submit their Valuations within

thirty (30) days after the Purchase Date as defined in Section 10.7(e). In
the event of a Party's failure to obtain an investment banking firm's
Valuation within thirty (30) days after the Purchase Date, the Valuation
will be the Valuation determined by the investment banking firm appointed
by the other Party. An example of the operation of the License Fee is set
forth in Attachment 10.7(a).

(b) If the difference between the lower Valuation and the higher
Valuation is not more than ***** of the higher Valuation, or if the
Valuations are equal, the final Valuation shall be the average of the
Valuations. If the difference between the ***** Valuations is more than
***** of the higher Valuation, the investment bankers will select a third
investment banking firm from those known as major bracket investment
banking firms, and that firm shall also prepare a Valuation. The third
investment banking firm will not have access to the Valuations prepared by
the other investment banking firms. The ***** Valuations that are the
closest in value then shall be averaged, and the resulting average shall be
the final Valuation.

(c) The purchase of the interest shall thereafter be consummated by
payment of the Valuation and the obligation to pay the Running Royalty
within ***** days after receipt of all investment bankers' valuations or
such later date upon which all necessary regulatory approvals have been
obtained and/or regulatory waiting periods have expired.

(d) The Party that sells its entire interest in the collaboration
("Seller") shall grant to the other Party ("Purchaser") an exclusive,
royalty-free license in the Territory under Seller's Patents and Seller's
Know-how to make, have made, use, import, offer for sale and sell Lead
Compounds and Validated Targets and a non-exclusive, royalty-free license
in the Territory under Seller's Patents and Seller's Know-how to make, have
made, use, import, offer for sale and sell other Seller's Technology.
"Seller's Patents," "Seller's Know-how" and "Seller's Technology" shall be
Procter & Gamble or Regeneron Technology, Patents and Know-how, depending
upon which Party is Seller.

(e) Each Party shall bear the expense of obtaining the Valuation of
the investment bankers selected by such Party, and if a third investment
banker is selected, the expense of obtaining its Valuation shall be borne
equally by the Parties.

(f) Unless otherwise agreed in writing by the Parties, the License Fee
for a license under Sections 10.4, 10.5 and 10.6 shall be calculated as of
the date of the Electing Company's notice that it elects to exercise the
Option under Sections 10.4 or 10.5 or the Purchasing Company's notice that
it desires to license the interest of the Party affiliated with the
Affected Company under Section 10.4 (such date shall be referred to as the
"Purchase Date").

(g) During the pendency of the Option election and valuation process
and any time period when the Parties are attempting to sell their interest
to a Third Party pursuant to Section 10.4(a)(i), the Parties shall continue
to perform their customary activities under this Agreement or any J-V
Agreement.

(h) Seller and Purchaser shall cooperate with each other in good
faith to facilitate the transfer of the Seller's interest in the
collaboration, including transferring Information relating to the
collaboration to Purchaser, so as to minimize disruption to the business.
As used in this Section, "Information" means any confidential information
and trade secrets, including but not limited to information relating to
inventions, disclosures, processes, systems, Know-how, methods, techniques,
formulations, drawings, patents, patent applications, sales and marketing
information, materials, services, research and development activities and
plans, clinical studies, manufacturing information and regulatory filings.

Article XI - Miscellaneous
--------------------------
11.1. Force Majeure. Neither Party shall lose any rights hereunder or be
liable to the other Party for damages or loss on account of failure of
performance by the Defaulting Party if the failure is occasioned by
government action, war, fire, explosion, flood, strike, lockout, embargo,
act of God, or any other similar cause beyond the reasonable control of the
Defaulting Party, provided that the Party claiming force majeure has
exerted all reasonable efforts to avoid or remedy such force majeure and
given prompt notice to the other Party.

11.2. Notices. Any notices or communications provided for in this Agreement
to be made by either of the Parties to the other shall be in writing, in
English, and shall be made by prepaid air mail with return receipt
addressed to the other at its address set forth above. Any such notice or
communication may also be given by hand or facsimile to the appropriate
designation with confirmation of receipt. Either Party may by like notice
specify an address to which notices and communications shall thereafter be
sent. Notices sent by mail shall be effective upon receipt; notices given
by hand shall be effective when delivered.

Notices for Regeneron shall be sent to:

Regeneron Pharmaceuticals, Inc.
Attn: Corporate Secretary
777 Old Saw Mill River Road

Tarrytown, New York 10591-6707

With copy to:

Regeneron Pharmaceuticals, Inc.
Attn: General Counsel
777 Old Saw Mill River Road
Tarrytown, New York 10591-6707

Notices for Procter & Gamble shall be sent to:

Procter & Gamble Pharmaceuticals, Inc.
Attn: President
One Procter & Gamble Plaza
Cincinnati, Ohio 45202

With copy to:

Procter & Gamble Pharmaceuticals, Inc.
Attn: Associate General Counsel-Patents
Health Care Research Center
8700 Mason-Montgomery Road
Mason, Ohio 45040

11.3. Governing Law. This Agreement shall be governed by the laws of the
State of Delaware, as such laws are applied to contracts entered into and to be
performed within such state. Any claim or controversy arising out of or related
to this Agreement or any breach hereof shall be submitted to arbitration
pursuant to Section 11.4. The United Nations Convention on Contracts for the
International Sale of Goods will not apply to this Agreement.

11.4. Arbitration. Subject to Sections 2.5 and 10.5, disagreements under
this Agreement shall be settled by arbitration in accordance with the commercial
arbitration rules of the American Arbitration Association. The parties further
agree that each such disagreement be submitted to a panel of three (3) impartial
arbitrators with each Party selecting one (1) arbitrator within fifteen (15)
days of a request for arbitration and the two (2) selected arbitrators selecting
a third arbitrator who is experienced in the United States pharmaceutical
industry within thirty (30) days after the request. Any arbitration hereunder
shall commence within thirty (30) days after appointment of the third arbitrator
and shall be held in Boston, Mass., U.S.A. Upon reasonable

notice and prior to any hearing, the Parties will allow document discovery and
will disclose all materials relevant to the subject matter of the dispute. The
arbitrators shall make final determinations as to any discovery disputes. The
decision of the arbitrators shall be rendered no later than sixty (60) days
after commencement of arbitration. The costs of arbitration shall be split by
the parties unless the arbitrators decide otherwise. Any judgment or decision
rendered by the panel shall be binding upon the Parties and shall be enforceable
by any court of competent jurisdiction.

11.5. Non-waiver of Rights. Except as specifically provided for herein, the
waiver from time to time by any of the parties of any of their rights or their
failure to exercise any remedy shall not operate or be construed as a continuing
waiver of same or of any other of such Party's rights or remedies provided in
this Agreement.

11.6. Severability. If any term, covenant, or condition of this Agreement
or the application thereof to any Party or circumstance shall, to any extent, be
held to be invalid or unenforceable, then (i) the remainder of this Agreement,
or the application of such term, covenant or condition to Parties or
circumstances other than those as to which it is held invalid or unenforceable,
shall not be affected thereby and each term, covenant, or condition of this
Agreement shall be valid and be enforced to the fullest extent permitted by law
and (ii) the Parties hereto covenant and agree to renegotiate any such term,
covenant, or application thereof in good faith in order to provide a reasonably
acceptable alternative to the term, covenant, or condition of this Agreement or
the application thereof that is invalid or unenforceable, and in the event that
the Parties are unable to agree upon a reasonably acceptable alternative, then
the Parties agree that a submission to arbitration shall be made in accordance
with Section 11.4 to establish an alternative to such invalid or unenforceable
term, covenant, or condition of this Agreement or the application thereof, it
being the intent that the basic purposes of this Agreement are to be
effectuated.

11.7. Entire Agreement. This Agreement sets forth all the covenants,
promises, agreements, warranties, representations, conditions, and
understandings between the Parties hereto in the scope of the Collaboration ,
with the exception of any agreements by the Parties executed at an even date
hereof, and supersedes and terminates all prior agreements and understanding
between the parties under this Agreement. No subsequent alteration, amendment,
change, or addition to this Agreement shall be binding upon the Parties hereto
unless reduced to writing and signed by the respective authorized officers of
the Parties.

11.8. Survival. Sections 5.3, 5.4, 5.5 and 8.1 shall survive the
termination of this Agreement for to the extent specified therein. Section 9.3
and any accrued obligations under this Agreement shall survive termination of
this Agreement without limit as to time.

11.9. Assignment.

(a) Procter & Gamble and Regeneron may assign any of their rights or
obligations under this Agreement in any country of the Territory to any
Affiliates; provided, however, that such assignment shall not relieve the
assigning Party of its responsibility for performance of its obligations
under this Agreement.

(b) The Parties recognize that each may perform some of its
obligations hereunder through Affiliates; provided, however, that Procter &
Gamble and Regeneron shall remain responsible and be guarantors of such
performance by their Affiliates and shall cause their Affiliates to comply
with the provisions of this Agreement in connection with such performance.

(c) Procter & Gamble and Regeneron may only assign their rights under
this Agreement in any country of the Territory to a Third Party with
written permission of the other Party, which permission will only be given
at its sole discretion.

11.10. Publicity.

(a) Procter & Gamble and Regeneron will jointly discuss, based on the
principles of Section 11.10(b), any press releases and any other public
statements regarding the execution and the subject matter of this
Agreement, the research to be conducted under this Agreement or any other
aspect of this Agreement, subject in each case to disclosure otherwise
required by law or regulation.

(b) In the discussion and agreement of Section 11.10(a), the
principles observed by Procter & Gamble and Regeneron will be accuracy, the
requirements for confidentiality under Article IX, the advantage a
competitor of Procter & Gamble or Regeneron may gain from any statement
under Section 11.10(a), the requirements of disclosure under any securities
laws or regulations of the United States, including those associated with
SEC and regulatory filings and public offerings, the restrictions imposed
by the Federal Food, Drug and Cosmetic Act, and the standards and customs
in the pharmaceutical industry for such disclosures by companies comparable
to Procter & Gamble and Regeneron.

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

11.12. No Solicitation. During the Term of this Agreement, the Parties
shall not directly or indirectly solicit the other Party's employees for
employment or other consulting arrangements.

Article XII - Execution
-----------------------

12.1. In witness whereof the Parties have executed this Agreement in
duplicate originals by their proper officers as of the date and year first
written above.

The Procter & Gamble Company

By: ________________________________
G. Gilbert Cloyd
Vice President - Pharmaceuticals

Regeneron Pharmaceuticals, Inc.

By: ________________________________
Leonard S. Schleifer, M.D., Ph.D.
President and Chief Executive Officer

Attachment 1.13(a)Regeneron Excluded Technology

BDNF, NT-3, AXOKINE, CNTF, small molecule agonists or antagonists of
neurotrophic factors as defined in the Field in the Glaxo/Regeneron
collaboration, small molecule agonsits and antagonists of cytokines and growth
factors as defined in the Field in the Pharmacopeia/Regeneron collaboration
agreement, and protein-based cytokine agonists and antagonist of the compounds
in the definition of the Field in the Pharmacopeia/Regeneron collaboration.

Attachment 2.2(a)

Initial Members of the Operating Committee

From Regeneron:
- --------------

Leonard S. Schleifer, M.D., Ph.D.
President and Chief Executive Officer

From Procter & Gamble:
- ---------------------

Gordon Hassing, Ph.D.
Vice President

Attachment 2.2(b)

Initial Members of the Program Committee

From Regeneron:
- ---------------

George Yancopoulos, Ph.D.

From Procter & Gamble:
- ----------------------

Nancy K. Eddy, Ph.D.

Attachment 3.1

Timing and Calculation of Research and/or Product Plan Budgets

Budget Process

1) Budget Preparation
------------------

o *****
o *****
o *****
o *****
o *****

2) Budget Preparation and Approval Cycle Timing
--------------------------------------------

o *****
o *****
o *****
o *****

3) Budget Monitoring
-----------------

o *****
o *****
o *****
o *****

Attachment 3.1 ("continued")

Budget Cost Development

1) Internal Costs
--------------
o *****
o *****

Attachment 3.1 ("continued")

*****

2) Third Party costs

o *****

Attachment 3.2(d)(1)

Research Payments to Regeneron

Fiscal Quarter Total Payments(1) ($000)
-------------- ------------------------
AMJ 1997 ***
JAS 1997 ***
OND 1997 ***
JFM 1998 ***
AMJ 1998 ***
JAS 1998 ***
OND 1998 ***
JFM 1999 ***
AMJ 1999 ***
JAS 1999 ***
OND 1999 ***
JFM 2000 ***
AMJ 2000 ***
JAS 2000 ***
OND 2000 ***
JFM 2001 ***
AMJ 2001 ***
JAS 2001 ***
OND 2001 ***
JFM 2002 ***
AMJ 2002 ***

- -------------------
(1) Excludes Inflation Adjustment Payments and any Allowable Research Expenses.
* If Procter and Gamble chooses to fund an additional *** Regeneron FTEs during
the Option Period pursuant to Section 3.2(a), this amount shall be increases
***** per quarter.

Attachment 3.2(d)(2)

Inflation Payment Adjustment

Fiscal Quarter Regeneron FTEs(2)
-------------- -----------------

JAS 1998 ***
OND 1998 ***
JFM 1999 ***
AMJ 1999 ***
JAS 1999 ***
OND 1999 ***
JFM 2000 ***
AMJ 2000 ***
JAS 2000 ***
OND 2000 ***
JFM 2001 ***
AMJ 2001 ***
JAS 2001 ***
OND 2001 ***
JFM 2001 ***
AMJ 2002 ***
JAS 2002 to the end of As agreed per the Research
the Research Term Collaboration Plan, but no
less than ***

Example:
- --------

June 1997 US CPI Value 157.0
June 1998 US CPI Value 161.6
June 1999 US CPI Value 166.1

FY 1998/99 Inflation Factor = (161.6 - 157.0) / 157.0 = 2.9%
FY 1999/00 Inflation Factor = (166.1 - 157.0) / 157.0 = 5.8%

Quarterly Inflation Payment Adjustment = (*****) x #FTEs x % change

Therefore:
- ----------

OND 1998 Inflation Payment Adjustment = ******
OND 1999 Inflation Payment Adjustment = ******

- -------------------
* This amount shall bew increased by *****, if Procter & Gamble chooses to fund
the ***** additional Regeneron FTEs pursuant to Section 3.2(a).

Attachment 3.2(d)(3)

Expenses Included in the Regeneron Research FTE Rate

o Payroll expense, including salaries, bonuses, commission, employee benefits
and employee-paid payroll taxes

o Employee training and education

o Administrative support

o *****

Attachment 6.1(b)

Each Party's Share of Royalties or Other Income

When Both Parties Opt Out

Party A's Party A's Share Party B's Party B's
Royalty Rate as of Royalties or Royalty Rate as Share of
an Opting Out Other Income an Opting Out Royalties or
Party Party Other Income

Example ***% *** ***% ***% *** ***%
1

Example ***% *** ***% ***% *** ***%
2

Example ***% *** ***% ***% *** ***%
3

Attachment 9.1(b)

Third Party Agreements Relating to Excluded Technology

Technology Development Agreement dated as of March 20, 1989, between Sumitomo
Chemical Company, Limited and Regeneron Pharmaceuticals, Inc.

Collaboration Agreement dated as of August 31, 1990, between Amgen Inc. and
Regeneron Pharmaceuticals, Inc.

Collaboration Agreement dated as of July 22, 1993, between Glaxo Group Limited
and Regeneron Pharmaceuticals, Inc.

Research Development Agreement dated as of June 2, 1994, between Sumitomo
Pharmaceuticals Company, Ltd., and Regeneron Pharmaceuticals, Inc.

Collaboration Agreement dated as of October 9, 1996, between Pharmacopeia, Inc.,
and Regeneron Pharmaceuticals, Inc.

Attachment 10.3(b)

Regeneron Key Executives

*****

Attachment 10.7(a)

Example of License Fee Operation

Scenario License Fee Operation

1. Party A is Opting Out Party with respect No License Fee; Party B
to all Compounds in all countries. continues to pay royalties for
Royalty Term pursuant to Section
Subsequently, Party A becomes Acquired 6.1
Company; Party B elects Option.

2. Party A is Opting Out Party with respect No License Fee on the ***** of
to *** of a total of *** in all which Party A Opted Out; Party B
countries. continues to pay royalties on
***** for the Royalty Term
Subsequently, Party A becomes Acquired pursuant to Section 6.1.
Company; Party B elects Option while
***** is a Research Compound and ***** is
in Phase II studies. For *****, the investment
bankers shall prepare a Fair
Market Value of such Compounds
and subtract out the net present
value of the Running Royalty for
***** and ***** from ***** of
the Fair Market Value to
calculate the Valuation. Party B
shall have the obligation to pay
the Running Royalty on *****.

3. Party A has not Opted Out with respect to For all Compounds, the
any of the ***** in research, development investment bankers shall prepare
and commercialization. *****. a Fair Market Value of such
Compounds in the Territory and
subtract out the net present
value of the Running Royalty for
***** and ***** from ***** of
the Fair Market Value to
calculate the Valuation. Party B
shall have the obligation to pay
the Running Royalty on *****.