Document:

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                                                                   EXHIBIT 10.52

          CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE
         SECURITIES AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

                             COLLABORATION AGREEMENT

                                 BY AND BETWEEN

                                   PFIZER INC.

                                       AND

                          EYETECH PHARMACEUTICALS, INC.

                          DATED AS OF DECEMBER 17, 2002

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                                TABLE OF CONTENTS

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                                                                                                                  PAGE
                                                                                                                  ----
<S>                                                                                                               <C>
ARTICLE 1 DEFINITIONS.........................................................................................       2

ARTICLE 2 CO-PROMOTION OF PRODUCTS IN THE US TERRITORY........................................................      18

     2.1  Co-Promotion........................................................................................      18
     2.2  License Grants......................................................................................      18
     2.3  Compliance With Law.................................................................................      18
     2.4  Detailing Obligations...............................................................................      18
     2.5  Training............................................................................................      18
     2.6  Promotional Materials and Call Center Communications................................................      20
     2.7  Samples.............................................................................................      20
     2.8  Distribution and Booking of Sales...................................................................      21
     2.9  Contract Sales Forces...............................................................................      21
     2.10  Delivery Technology Development Agreement..........................................................      21

ARTICLE 3 MANAGEMENT OF ALLIANCE..............................................................................      22

     3.1  Committee/Subcommittees.............................................................................      22
     3.2  Meetings............................................................................................      22
     3.3  Clinical Development/Regulatory Subcommittee........................................................      23
     3.4  Commercialization Subcommittee......................................................................      26
     3.5  Manufacturing Subcommittee..........................................................................      27
     3.6  Joint Operating Committee...........................................................................      29
     3.7  Deadlocks...........................................................................................      30
     3.8  Limitation on Decision-Making Authority.............................................................      30

ARTICLE 4 CLINICAL AND REGULATORY MATTERS.....................................................................      31

     4.1  Clinical and Regulatory Matters in the US Territory.................................................      31
     4.2  Clinical and Regulatory Matters in the ROW Territory................................................      33
     4.3  Inquiries, Adverse Events, etc. ....................................................................      35
     4.4  Pfizer's Performance of Regulatory Services Agreement Obligations...................................      36

ARTICLE 5 PRODUCT DEVELOPMENT.................................................................................      37

     5.1  Development Plan and Budget.........................................................................      37
     5.2  AMD Product and DME Product Development.............................................................      38
     5.3  Development of Products for Additional Indications in the Field.....................................      38

ARTICLE 6  LAUNCH, CO-PROMOTION AND DETAILING.................................................................      39

     6.1  Co-Promotion of Products............................................................................      39
     6.2  Marketing Plan and Budget...........................................................................      39
     6.3  Detailing...........................................................................................      40
     6.4  Detailing Reports...................................................................................      40
     6.5  Detail Shortfalls...................................................................................      41
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<TABLE>
<S>                                                                                                               <C>
     6.6  Sales Force Responsibilities........................................................................      44
     6.7  Product Information.................................................................................      45
     6.8  Orders..............................................................................................      45
     6.9  Audit...............................................................................................      45
     6.10  Third Party Reports................................................................................      45
     6.11  Medical Claims.....................................................................................      45
     6.12  Manufacturing......................................................................................      46
     6.13  Customer Support...................................................................................      50

ARTICLE 7 PAYMENT PROVISIONS..................................................................................      50

     7.1  Payment Currency....................................................................................      50
     7.2  Payments............................................................................................      50

ARTICLE 8 EXPENSE SHARING AND COMPENSATION....................................................................      51

     8.1  Sharing of Development Costs........................................................................      51
     8.2  Responsibility for Regulatory Costs.................................................................      53
     8.3  Responsibility for Cost of Goods Sold...............................................................      53
     8.4  Responsibility for Marketing Expenses...............................................................      54
     8.5  Net Sales Reports...................................................................................      54
     8.6  Quarterly Reconciliation of Net Sales and Expenses..................................................      54
     8.7  Offset..............................................................................................      56

ARTICLE 9 ACCOUNTING AND REPORTS..............................................................................      56

     9.1  Books and Records...................................................................................      56
     9.2  Audits..............................................................................................      56
     9.3  Sales Force Efforts.................................................................................      57

ARTICLE 10  INTELLECTUAL PROPERTY RIGHTS AND LABELING.........................................................      58

     10.1  Trademark and Corporate Logos......................................................................      58
     10.2  Copyrights and Proprietary Programs................................................................      61
     10.3  Developments.......................................................................................      62
     10.4  Third Party Agreements.............................................................................      62

ARTICLE 11  CONFIDENTIAL INFORMATION..........................................................................      63

     11.1  Treatment of Confidential Information..............................................................      63
     11.2  Confidential Information...........................................................................      64

ARTICLE 12  REPRESENTATIONS, WARRANTIES AND INDEMNIFICATION...................................................      65

     12.1  Eyetech's Representations..........................................................................      65
     12.2  Pfizer's Representations...........................................................................      66
     12.3  No Warranties......................................................................................      67
     12.4  General Indemnification in Favor of Pfizer.........................................................      67
     12.5  General Indemnification in Favor of Eyetech........................................................      68
     12.6  Product Liability and Intellectual Property Infringement Indemnification...........................      69
     12.7  "Losses"...........................................................................................      72
     12.8  No Consequential or Punitive Damages...............................................................      73
     12.9  General Indemnification Procedures.................................................................      73
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<TABLE>
<S>                                                                                                               <C>
ARTICLE 13  TERM AND TERMINATION..............................................................................      77

     13.1  Term...............................................................................................      77
     13.2  Termination for Breach.............................................................................      77
     13.3  HSR Denial.........................................................................................      79
     13.4  Detail Shortfalls..................................................................................      79
     13.5  Breach of Non-Competition Obligations..............................................................      80
     13.6  Changes of Control.................................................................................      80
     13.7  Termination of License Agreement...................................................................      80
     13.8  Sales Threshold Termination........................................................................      81
     13.9  Survival of Obligations............................................................................      81

ARTICLE 14  NON-COMPETITION; DETAILING SERVICES AGREEMENT.....................................................      84

     14.1  Non-Competition....................................................................................      84
     14.2  Acquisitions Involving Competing Products..........................................................      86
     14.3  Detailing Services Agreement; Additional Agreements................................................      87

ARTICLE 15  DISPUTE RESOLUTION................................................................................      88

     15.1  Arbitration........................................................................................      88
     15.2  No Limitation......................................................................................      89

ARTICLE 16  HSR MATTERS.......................................................................................      90

     16.1  HSR Filings........................................................................................      90
     16.2  HSR Cooperation; Further Assurances................................................................      90
     16.3  Activities Prior to the Effective Date.............................................................      91

ARTICLE 17 MISCELLANEOUS......................................................................................      91

     17.1  Governing Law......................................................................................      91
     17.2  Jurisdiction.......................................................................................      91
     17.3  Waiver.............................................................................................      91
     17.4  Notices............................................................................................      92
     17.5  Entire Agreement...................................................................................      93
     17.6  Headings...........................................................................................      93
     17.7  Severability.......................................................................................      93
     17.8  Registration and Filing of the Agreement...........................................................      94
     17.9  Assignment.........................................................................................      94
     17.10 Successors and Assigns.............................................................................      94
     17.11 Divestiture by Pfizer..............................................................................      95
     17.12 Counterparts.......................................................................................      96
     17.13 Force Majeure......................................................................................      96
     17.14 Non-Solicitation of Employees......................................................................      97
     17.15  Press Releases and Other Disclosures..............................................................      97
     17.16  Third-Party Beneficiaries.........................................................................      98
     17.17  Relationship of the Parties.......................................................................      98
     17.18  Performance and Compliance by Affiliates..........................................................     100
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<TABLE>
<S>                                 <C>
EXHIBIT 1.20               -        Group/Joint Details
EXHIBIT 1.52               -        Call Center Costs
EXHIBIT 2.5                -        Sales Force Training Program
EXHIBIT 3.4(d)             -        Matters where Eyetech Possesses Special Expertise
                                    or has Special Relationships
EXHIBIT 3.4(e)             -        Initially Planned Phase III(b)/IV Product Studies
EXHIBIT 5.1(a)             -        Development Programs for the AMD Product and the DME
                                    Product
EXHIBIT 5.1(b)             -        AMD Agreed Development Costs and the DME Agreed
                                    Development Costs
EXHIBIT 6.2                -        Marketing Budgets and Detailing Requirements
EXHIBIT 6.12(a)            -        Pre-Existing Clinical Supply Agreements
EXHIBIT 10.4               -        Third Party Agreements
EXHIBIT 12.6(a)(iii)       -        Certain Product Liability Matters
EXHIBIT 12.6(b)(iii)(A)    -        Eyetech 2002 Clinical Supply Costs
EXHIBIT 12.6(b)(iii)(B)    -        Certain Third Party Intellectual Property
EXHIBIT 17.15              -        Joint Press Release
EXHIBIT 17.15(c)           -        Permitted Disclosures
</TABLE>

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<PAGE>

                             COLLABORATION AGREEMENT

         THIS COLLABORATION AGREEMENT dated as of December 17, 2002 (the
"Execution Date"), between Pfizer Inc. ("Pfizer"), a corporation organized under
the laws of the State of Delaware, having a business address at 235 East 42nd
Street, New York, New York 10017-5755, and Eyetech Pharmaceuticals, Inc.
("Eyetech"), a corporation organized under the laws of the State of Delaware,
having a business address at 500 Seventh Avenue, 18th Floor, New York, New York
10018.

         WHEREAS, the Parties have executed the Other Product-Related Agreements
(as defined below) with respect to the aptamer known as Macugen;

         WHEREAS, the Parties have also executed the Equity Agreements (as
defined below) with respect to purchases of shares of Eyetech capital stock that
have been and/or will be made from Eyetech by Pfizer, Pfizer Ireland
Pharmaceuticals, a Pfizer Affiliate organized under the laws of the Republic of
Ireland ("Pfizer Ireland"), and/or another Pfizer Affiliate designated by
Pfizer;

         WHEREAS, the Parties have also executed the Detailing Services
Agreement (as defined below); and

         WHEREAS, the Parties would like to set forth the terms and conditions
pursuant to which they will collaborate in connection with the worldwide
development and commercialization of products containing or based on the Macugen
aptamer and with respect to certain other matters as described in this Agreement
and in the Other Product-Related Agreements.

         NOW, THEREFORE, the Parties agree as follows:

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                                    ARTICLE 1

                                   DEFINITIONS

         The following terms, whether used in the singular or plural, shall have
the following meanings:

         1.1      "Act" means both the United States Food, Drug and Cosmetic
Act, as amended, and the regulations promulgated under the foregoing.

         1.2      "Affiliate" means any Person directly or indirectly controlled
by, controlling or under common control with, a Party, but only for so long as
such control shall continue. For purposes of this definition, "control"
(including, with correlative meanings, "controlled by", "controlling" and "under
common control with") means, with respect to a Person, possession, direct or
indirect, of (a) the power to direct or cause direction of the management and
policies of such Person (whether through ownership of securities or partnership
or other ownership interests, by contract or otherwise), or (b) at least 50% of
the voting securities (whether directly or pursuant to any option, warrant or
other similar arrangement) or other comparable equity interests. For the
avoidance of doubt, neither of the Parties shall be deemed to be an "Affiliate"
of the other.

         1.3      "AMD Product" means a Product developed for use in the
treatment of age-related macular degeneration.

         1.4      "API Bulk Drug Substance Supplier" means a third-party
supplier of active pharmaceutical ingredient bulk drug substance for Products
with which Eyetech or Pfizer enters into a supply agreement pursuant to Section
6.12.

         1.5      "Approval" means receipt from FDA of approval to market a drug
product in the US Territory.

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         1.6      "Bankruptcy Code" means 11 USC Sections 101-1330, as amended.

         1.7      "beneficial ownership" (and other correlative terms) by a
Person means, with respect to any security: (a) such Person or any of such
Person's Affiliates directly or indirectly owns such security; (b) such Person
or any of such Person's Affiliates has the right to acquire such security
(whether such right is exercisable immediately or only after the passage of
time) pursuant to any agreement, arrangement or understanding (whether or not in
writing) or upon the exercise of conversion rights, exchange rights, rights,
warrants or options, or otherwise; or (c) ownership, direct or indirect, by any
other Person with which such Person or any of such Person's Affiliates has any
agreement, arrangement or understanding for the purpose of acquiring, holding,
voting or disposing of such security; provided, however, that a Person shall not
be deemed to have beneficial ownership of any security by virtue of an
agreement, arrangement or understanding to vote such security that arises solely
from a revocable proxy or consent given to such Person in response to a public
proxy or consent solicitation made pursuant to, and in accordance with, the
applicable rules and regulations of the Securities Exchange Act of 1934, as
amended.

         1.8      "Business Day" means a day that is not a Saturday, Sunday or a
day on which banking institutions in New York, New York are authorized by Law to
remain closed.

         1.9      "Call Center" means the call center to be established by
Pfizer and substantially dedicated to receiving and answering Product-related
inquiries and complaints from or on behalf of, as applicable, Product-users,
physicians, managed care organizations, and others residing in the US Territory.

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         1.10     "Change in Control" means, with respect to a Party, an event
where:

                  (a)      any Person or group of Persons (as the term "group"
is interpreted pursuant to Rule 13d-5 under the Securities Exchange Act of 1934,
as amended) acquires beneficial ownership of capital stock of the Party (other
than (x) directly from such Party or (y) from underwriter(s) of such Party's
capital stock in a public offering) entitling the holder(s) thereof to at least
a majority of the voting power of the then outstanding capital stock of such
Party with respect to the election of directors of such Party, or

                  (b)      the Party enters into a merger, consolidation,
reorganization or similar transaction with another Person (the "Acquiring
Corporation") in which less than a majority of the voting power of the
outstanding capital stock of such Party (if it is the surviving entity) or of
the Acquiring Corporation (if it is the surviving entity) with respect to the
election of directors following such transaction is held by Persons who were
shareholders of such Party immediately prior to such transaction, or

                  (c)      the Party sells to any Person(s) in one or more
related transactions properties or assets representing all or substantially all
of the properties and assets of such Party.

         1.11     "CMC" means the chemistry, manufacturing and controls section
of the Product NDA.

         1.12     "Code" or "Codes" means the Code on Interactions with
Healthcare Professionals promulgated by the Pharmaceutical Research and
Manufacturers of America (PhRMA), the American Medical Association Guidelines on
Gifts to Physicians, and the PhRMA Principles on Conduct of Clinical Trials and
Communication of Clinical Trial Results, as any of the foregoing may be amended.

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         1.13     "Commercially Reasonable Efforts" means, with respect to a
Product, commercially reasonable efforts, which in no event will be less than
the efforts the Party required to make such efforts generally uses (as
applicable in the context used in this Agreement) in developing, seeking
Approvals, manufacturing, promoting, detailing and marketing its other
pharmaceutical products (if any) that are comparable to such Product, taking
into account product labeling or anticipated labeling, market potential, past
performance (if any), economic return potential, medical and clinical
considerations, the regulatory environment, and competitive market conditions in
the therapeutic area, all as measured by the facts and circumstances at the time
such efforts are due.

         1.14     "Competing Product" means [**].

         1.15     "Consumer Price Index" or "CPI" means the Consumer Price Index
- Urban Wage Earners and Clerical Workers, U.S. City Average, All Items, 1982-84
= 100, published by the United States Department of Labor, Bureau of Statistics
(or its successor equivalent index).

         1.16     "Co-Promotion" means the joint marketing and promotion
(including without limitation Detailing) of the Products in the US Territory as
described in Article 6. "Co-Promote" when used as a verb shall mean to engage in
the activities described in Article 6.

         1.17     "Co-Promotion Budget" is defined in Section 6.2.

         1.18     "Co-Promotion Term" means the period from the Effective Date
until the later of (a) the expiration of the last to expire Valid Claim (as such
term is defined in the License Agreement) in the United States of America and
(b) 15 years after Launch of the last Product in the US Territory, unless sooner
terminated as provided in this Agreement.

         1.19     "Cost of Goods Sold" means Manufacturing Costs plus or minus
an adjustment to be mutually agreed by the Parties from time to time for
variances between the standard cost

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component(s) of Manufacturing Costs and the actual costs incurred by the Parties
that such standard cost component(s) are intended to cover.

         1.20     "Detail" means a face-to-face contact of either an Eyetech or
Pfizer Sales Representative, as the case may be, with a medical professional
with prescribing authority during which scientific and/or medical information
about a Product is discussed. A Detail does not include a reminder or sample
drop. With respect to certain group or institutional presentations, or joint
details by Sales Representatives of both parties, Exhibit 1.20 sets forth how
such presentations will be counted for determination of the number of Details.
Details shall be measured by each Party's internal recording of such activity,
provided that such measurement shall be on the same basis as the recording
Party's measurement for its sales representatives detailing of such recording
Party's other products (if any), consistently applied throughout the
Co-Promotion Term. When used as a verb, the term "Detailing" means to engage in
the activity of a Detail.

         1.21     "Detailing Services Agreement" means the Detailing Services
Agreement dated as of the Execution Date between the Parties relating to an
arrangement by which Eyetech may, at its option, detail for Pfizer on a contract
basis Xalatan, Xalcom, and any other products approved for use in the Field
containing latanoprost as an active ingredient, including without limitation
Xalatan and Xalcom life-cycle products, that are owned by Pfizer or its
Affiliates.

         1.22     "Detailing Report" is defined in Section 6.4.

         1.23     "Detail Requirement" means the number of Details that each
Party's Sales Representatives are required to perform in the US Territory
pursuant to a Marketing Plan.

         1.24     "Development Costs" means the costs, including without
limitation Out-of-Pocket Costs in relation to the preclinical and clinical
development of Products and the conduct

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of Product Studies and direct and identifiable variable personnel costs in
relation to preclinical development of Products and the conduct of preclinical
Product Studies, as set forth in each relevant Development Plan; provided,
however, Development Costs shall not include any (a) Out-of-Pocket Costs paid by
either Party prior to December 1, 2002, (b) [**], or (c) except for direct and
identifiable variable personnel costs explicitly provided for in this Section
1.24, Internal Costs.

         In addition, Development Costs shall include Out-of-Pocket Costs and
direct and identifiable variable personnel costs of (w) manufacturing clinical
supplies of Products, (x) process development for clinical and commercial scale
manufacture of Products, including without limitation manufacturing process
optimization in accordance with Section 6.12(h), (y) stability studies and (z)
providing manufacturing transition support in accordance with Section 6.12.

         1.25     "Development Plan" is defined in Section 5.1.

         1.26     "Distribution Agreement" means the Distribution Agreement
dated as of the Execution Date between the Parties relating to the provision by
Pfizer of Product distribution services in the US Territory on a contract basis
for Eyetech.

         1.27     "DME Product" means a Product developed for use in the
treatment of diabetic macular edema.

         1.28     "DOJ" means the United States Department of Justice.

         1.29     "Effective Date" means the HSR Clearance Date.

         1.30     "Equity Agreements" means (a) the Series D Preferred Stock
Purchase Agreement dated as of the Execution Date, to which the Parties and
Pfizer Ireland are parties, and (b) the Amended and Restated Investors' Rights
Agreement, the Amended and Restated Right of First

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Refusal and Co-Sale Agreement and the Amended and Restated Voting Agreement,
each to be entered into by Eyetech and Pfizer Ireland after the Execution Date
in accordance with the aforementioned Series D Preferred Stock Purchase
Agreement.

         1.31     "FDA" means the United States Food and Drug Administration and
any successor agency thereto.

         1.32     "Field" means the prevention, treatment or control of all
ophthalmic diseases or conditions.

         1.33     "Fill and Finish Services Supplier" means a third party
supplier of fill and finish services necessary to produce Products in finished
(i.e., ready for administration to patients) form for sale in the US Territory
with which Eyetech or Pfizer enters into an agreement pursuant to Section 6.12.

         1.34     "First Approval" means the first Approval of a Product.

         1.35     "FTC" means the United States Federal Trade Commission.

         1.36     "Funded Inventory Build Costs" means the amount of pre-Launch
Manufacturing Costs funded by each of the Parties pursuant to Section 6.12(f).
Each Party's Funded Inventory Build Costs shall be increased by amounts funded
pursuant to Section 6.12(f) and reduced by the Inventory Build Credit applied
pursuant to Section 8.3.

         1.37     "GAAP" means accounting principles generally accepted in the
United States of America.

         1.38     "GMP" means the Good Manufacturing Practices regulations
promulgated by the FDA under the Act as of the time of manufacture of the
applicable Products.

         1.39     "Governmental Authority" means any court, agency, department
or other instrumentality of any foreign, federal, state, county, city or other
political subdivision.

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         1.40     "HSR Act" means the Hart-Scott-Rodino Antitrust Improvements
Act of 1976, as amended (15 U.S.C. Sec. 18a), and the rules and regulations
promulgated thereunder.

         1.41     "HSR Clearance" means either (a) early termination of the
applicable waiting period under the HSR Act with respect to the HSR Filings or
(b) expiration of the applicable waiting period under the HSR Act with respect
to the HSR Filings.

         1.42     "HSR Clearance Date" means the earlier of (a) the date on
which the FTC or DOJ shall notify Eyetech and Pfizer of early termination of the
applicable waiting period under the HSR Act or (b) the day after the date on
which the applicable waiting period under the HSR Act expires.

         1.43     "HSR Filings" means the filings by Pfizer and Eyetech with the
FTC and the Antitrust Division of the DOJ of a Notification and Report Form for
Certain Mergers and Acquisitions (as that term is defined in the HSR Act) with
respect to the matters set forth in the Transaction Agreements, together with
all required documentary attachments thereto.

         1.44     "IND" means an investigational new drug application filed with
the FDA with respect to a Product.

         1.45     "Internal Costs" means a Party's and/or its Affiliate's costs
and expenses for overhead, personnel, rent, depreciation and amortization,
utilities, equipment leases, general and administrative expenses and similar
items.

         1.46     "Know-How" means unpatented technical and other information
which is not known to the public, including information comprising or relating
to concepts, discoveries, data, designs, formulae, methods, models, assays,
research plans, procedures, designs for experiments and tests and results of
experimentation and testing (including results of research or development),
together with processes, including manufacturing processes, specifications,

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techniques, chemical, pharmacological, toxicological, clinical, analytical and
quality control data, trial data, case report forms, data analyses, reports or
summaries, including documents (which shall include paper, notebooks, books,
files, ledgers, records, tapes, discs, diskettes, CD-ROM and any other media on
which the foregoing information can be permanently stored) containing any of the
foregoing information. The fact that an item is known to the public shall not be
taken to exclude the possibility that a compilation including the item, and/or a
development related to the item, is (or remains) not known to the public.

         1.47     "Launch" means the initial shipping of a Product as a, or for,
commercial sale to an unaffiliated third party, excluding any shipping for test
marketing, clinical trial purposes or compassionate or similar use.

         1.48     "Law" or "Laws" means all laws, statutes, rules, Codes,
regulations, orders, judgments and/or ordinances of any Governmental Authority.

         1.49     "License Agreement" means the License Agreement dated as of
the Execution Date between the Parties.

         1.50     "Major Country" means France, Germany, Italy, Spain or the
United Kingdom.

         1.51     "Manufacturing Costs" means costs that relate to (a) Products
supplied by a non-Affiliate third party, or (b) Products manufactured directly
by a Party or an Affiliate of a Party. In the case of (a), Manufacturing Costs
shall be a "standard cost" per unit, which standard cost shall include (i) the
amount paid to such a third party, plus (ii) the manufacturing Party's (i.e.,
the Party then responsible for manufacturing pursuant to Section 6.12) direct
and identifiable Internal Costs and Out-of-Pocket Costs, which amounts shall be
subject to the other Party's reasonable approval, incurred or accrued by the
manufacturing Party in connection with quality assurance, supply chain
management, and similar activities comprising the manufacturing

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Party's oversight of the manufacturing process of the non-Affiliate third party.
In the case of (b), Manufacturing Costs shall be a "standard cost" per unit,
which standard cost shall include the cost of raw materials, labor, and other
direct and identifiable variable costs and appropriate costs for equipment
pools, plant operations and plant support services. The costs for plant
operations and support services would include utilities, maintenance,
engineering, safety, human resources, finance, plant management and other
similar activities. The plant operations and support services costs would be
allocated on a mutually agreed basis consistent with GAAP. Costs which cannot be
identified to a specific activity supporting product manufacturing, such as
charges for corporate overhead which are not controllable by the manufacturing
plant, shall not be included in standard cost.

         1.52     "Marketing Expenses" means all Out-of-Pocket Costs paid or
accrued by a Party pursuant to a Marketing Plan and directly related to the
Co-Promotion of the Products in the US Territory, including those in connection
with:

                  (a) [**]

                  (b) [**] for the Products [**]; (iii) [**] the Products [**];
(iv) [**]; (v) [**] the Products [**]; and (vi) [**] the Products [**]. With
respect to [**] as determined in accordance with [**] subject to [**]; and

                  (c) [**] the Products.

         Notwithstanding the foregoing, Marketing Expenses shall not include any
costs or expenses incurred prior to the Execution Date, and shall include (i)
Eyetech's Out-of-Pocket Costs and direct and identifiable variable personnel
costs incurred pursuant to Section 6.13 and amounts paid by Eyetech to Pfizer
pursuant to the Distribution Agreement and (ii) filing or other user fees or
maintenance fees paid to the FDA in order for Eyetech or Pfizer, as the case may
be, to obtain or maintain regulatory approval for the Products.

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         All other Out-of-Pocket Costs incurred in the Co-Promotion of the
Products in the US Territory, but not specifically identified above, but which
have been approved by the CSC or provided for in the Marketing Plan, shall be
accounted for and deemed Marketing Expenses for all purposes of this Agreement.

         1.53     "Marketing Plan" is defined in Section 6.2.

         1.54     "NDA" means a New Drug Application filed with the FDA with
respect to a Product.

         1.55     "Net Sales" means the gross amounts billed or invoiced by
Eyetech and its Affiliates for Products in the US Territory, less the following
deductions:

                  (a)      trade, quantity and cash discounts allowed, but
expressly excluding discounts or allowances offered as part of a package of
products that includes a Product sold by Eyetech or its Affiliates;

                  (b)      refunds, chargebacks and any other allowances which
effectively reduce the net selling price;

                  (c)      actual product returns, credits and allowances
allowed to customers, and actual bad debts;

                  (d)      rebates actually paid or credited to any governmental
agency (or branch thereof) or to any third party payor, administrator or
contractee;

                  (e)      discounts mandated by, or granted to meet the
requirements of, applicable state, provincial or federal law, wholesaler,
including required chargebacks and retroactive price reductions;

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<PAGE>

                  (f)      transportation, freight, postage charges and other
charges, such as insurance, relating thereto, in each case included as a
specific line item on an invoice to such third parties; and

                  (g)      taxes, excises or other governmental charges upon or
measured by the production, sale, transportation, delivery or use of goods, in
each case included as a specific line item on an invoice to such third parties.

         If any such sales to third parties are made in transactions that are
not at arm's length between the buyer and the seller, then the gross amount to
be included in the calculation of Net Sales shall be the amount that would have
been invoiced had the transaction been conducted at arm's length. Such amount
that would have been invoiced shall be determined, wherever possible, by
reference to the average selling price of the relevant Product in arm's-length
transactions in the US Territory.

         If Eyetech or its Affiliate sells a Product in unfinished form to a
third party for resale, then the gross amount to be included in the calculation
of Net Sales arising from such sale shall be the amount invoiced by the third
party upon resale, in lieu of the amounts invoiced by Eyetech or its Affiliates
when selling the Product in unfinished form. Otherwise, where Eyetech or its
Affiliate sells a Product in finished form to a third party that does not
require a sublicense under the Eyetech Patents for further resale (each such
third party hereinafter a "Distributor"), the amount to be included in the
calculation of Net Sales shall be the price invoiced from Eyetech or its
Affiliate to the third party, not the amount invoiced by the third party upon
resale.

         If, in addition to or in lieu of a transfer price paid for quantities
of Product supplied, any Distributor provides consideration to Eyetech or its
Affiliate in connection with any Product or the Distributor's rights or
relationship with Eyetech or its Affiliate in relation thereto, then such

                                       13

<PAGE>

consideration shall be included in the calculation of Net Sales in the Quarter
in which it becomes due to Eyetech or its Affiliate (as applicable).

         Notwithstanding the foregoing, amounts received by Eyetech or its
Affiliates (x) for the sale of Products among Eyetech and its Affiliates for
resale or (y) for the sale of Products by Eyetech or its Affiliates to Pfizer or
its Affiliates or sublicensees for resale in the ROW Territory, shall not be
included in the computation of Net Sales hereunder.

         Net Sales shall be determined from books and records maintained in
accordance with GAAP, consistently applied throughout the organization and
across all products of the entity whose sales of Product are giving rise to Net
Sales.

         1.56     "Other Product-Related Agreements" means the License
Agreement, the Distribution Agreement and the Regulatory Services Agreement.

         1.57     "Out-of-Pocket Costs" means costs and expenses paid to third
parties (or payable to third parties and accrued in accordance with GAAP), other
than Affiliates or employees, by either Party after the Execution Date (or, in
the case of Development Costs, after December 1, 2002).

         1.58     "Party" means either Eyetech or Pfizer; "Parties" means both
Eyetech and Pfizer.

         1.59     "Person" means any natural person or any corporation, company,
partnership, joint venture, firm or other entity, including without limitation a
Party.

         1.60     "Pharmacia Merger" means the merger contemplated by the
Agreement and Plan of Merger dated as of July 13, 2002 among Pfizer, Pilsner
Acquisition Sub Corp., a wholly owned Subsidiary of Pfizer, and Pharmacia
Corporation ("Pharmacia") (as the same may be amended or supplemented or
restated from time to time, the "Pharmacia Merger Agreement") providing for the
merger of Pilsner Acquisition Sub Corp. with and into Pharmacia.

                                       14

<PAGE>

         1.61     "Phase III Clinical Study" means a Product Study with study
design and statistical power intended to meet the requirement for Approval by
the FDA.

         1.62     "Phase III(b)/IV Product Study" means a clinical study
designed to support or profile a Product or intended to be the basis of a
post-approval Product filing, including without limitation proposed label
changes not explicitly described in Section 1.64 below, but not including any
clinical study intended to be the basis of any regulatory filing for initial FDA
or other Governmental Authority approval for marketing of Products or conducted
as a condition to the prior receipt of any regulatory approval for marketing of
Products. Phase III(b)/IV Product Studies shall include, without limitation,
epidemiological studies and modeling and pharmacoeconomic studies.

         1.63     "Product" means any product, that (a) contains or is based on
the anti-VEGF aptamer known as "Macugen" or "EYE001", including any metabolites
or prodrugs of such aptamer or any hydrates, conjugates, salts, esters, isomers,
polymorphs or analogues of any of the foregoing, either alone or in combination
with one or more other therapeutically active substances, and (b) is for use in
the Field; including for the avoidance of doubt any AMD Product, DME Product or
other product developed in accordance with the terms of this Agreement for any
indication in the Field other than AMD or DME, or as a new un-pegylated
formulation of any such AMD Product, DME Product or other product (each such
other product, an "Additional Developed Product").

         1.64     "Product Studies" means clinical, preclinical, safety, and
other studies that are designed to support FDA or other Governmental Authority
approval for marketing of Products. For the avoidance of doubt, Product Studies
shall not include [**], but shall include [**].

         1.65     "PSURs" means periodic safety update reports.

                                       15

<PAGE>

         1.66     "Quarter" means (i) with respect to Eyetech, each of the
periods ending on March 31, June 30, September 30 and December 31, and (ii) with
respect to Pfizer each of the periods ending at the end of each of the four (4)
thirteen (13) week periods as used by Pfizer as reported in its filings with the
Securities and Exchange Commission, the first such period commencing on January
1 of any year, and the terms "Eyetech Quarter" and "Pfizer Quarter" shall be
construed accordingly.

         1.67     "Regulatory Costs" means the costs, including without
limitation the Out-of-Pocket Costs and direct and identifiable variable
personnel costs, in relation to making or supporting regulatory filings in the
US Territory; provided, however, Regulatory Costs shall not include any (a)
Out-of-Pocket Costs paid by either Party prior to the Execution Date, (b) costs
of making or supporting regulatory filings in the ROW Territory, or (c) except
for direct and identifiable variable personnel costs explicitly provided for in
this Section 1.67, Internal Costs. In addition, Regulatory Costs shall include
amounts paid by Eyetech to Pfizer under the Regulatory Services Agreement.

         1.68     "Regulatory Services Agreement" means the Regulatory Services
Agreement dated as of the Execution Date between the Parties relating to the
provision by Pfizer of specified regulatory services in the US Territory on a
contract basis for Eyetech.

         1.69     "ROW Territory" means all countries in the world other than
the US Territory.

         1.70     "Sales Representative" means an individual who engages in
Detailing and other promotional efforts in the Field with respect to the
Products and who has been trained and is employed by either Pfizer or Eyetech or
their respective Affiliates.

         1.71     "Senior Executive" means, with respect to Eyetech, the Chief
Executive Officer of Eyetech, and with respect to Pfizer, a corporate officer of
Pfizer with senior decision-making

                                       16

<PAGE>

authority; "Senior Executives" means both such officers. Pfizer shall initially
designate Karen Katen as its Senior Executive.

         1.72     "Specifications" means the specifications for the manufacture
and packaging of the Products consistent with the NDA.

         1.73     "Subsidiary" means, with respect to a Party, a majority or
wholly-owned direct or indirect subsidiary of such Party.

         1.74     "Territory" means the US Territory and the ROW Territory.

         1.75     "Trademark" means (i) MACUGEN and (ii) any other trademark
associated with the Products that may be selected by the Parties in accordance
with Section 10.1(e), excluding the respective corporate names and logos of the
Parties.

         1.76     "Transaction Agreements" means this Agreement, the Other
Product-Related Agreements, the Equity Agreements and the Detailing Services
Agreement.

         1.77     "US Territory" means the United States of America, including
its territories, possessions and Puerto Rico.

         1.78     "Xalatan" means latanoprost ophthalmic solution which is
presently sold by Pharmacia under the trademark Xalatan(R) as a single entity.

         1.79     "Xalcom" means product containing as active ingredients
latanoprost and timolol and which is presently sold by Pharmacia under the
trademark Xalcom(R) as a single entity.

         1.80     "Year" means each calendar year during the Co-Promotion Term.

                                       17

<PAGE>

                                    ARTICLE 2

                  CO-PROMOTION OF PRODUCTS IN THE US TERRITORY

         2.1      Co-Promotion. Subject to the terms of this Agreement, the
Parties shall Co-Promote Products in the US Territory co-exclusively with each
other as provided in this Agreement.

         2.2      License Grants. Each Party's rights under intellectual
property rights owned or controlled by the other Party, with respect to the
development, manufacture and Co-Promotion of Products in the US Territory, are
as set forth in the License Agreement.

         2.3      Compliance With Law. Both Pfizer and Eyetech shall Co-Promote
the Products in the US Territory in accordance with applicable Law, the terms of
this Agreement and the then-current Marketing Plan. Neither Party shall be
required to undertake any action or inaction, or to incur expenditures in
connection with any such action or inaction under this Agreement that it
believes, in good faith, may violate any Law.

         2.4      Detailing Obligations. Subject to Exhibit 6.2, the Detailing
obligations of the Parties in respect of the Products shall be as set out in the
then-current Marketing Plan.

         2.5      Training.

                  (a)      Pfizer shall, at its sole expense, provide initial
sales and product training in connection with the first Product Detailed by
Eyetech Sales Representatives in the US Territory pursuant to this Agreement for
up to forty (40) Eyetech Sales Representatives. Eyetech may also elect to have
Pfizer provide such initial sales and product training to an additional fifteen
(15) Eyetech Sales Representatives, in which case Eyetech shall reimburse Pfizer
for Pfizer's Out-of-Pocket Costs and direct and identifiable variable personnel
costs incurred in connection with such training for such additional Sales
Representatives. Such training shall, at Eyetech's option,

                                       18

<PAGE>

be conducted in multiple program sessions; provided that Pfizer shall not be
required to provide more than four (4) separate program sessions, the first
three (3) of which shall be for not less than ten (10) Eyetech Sales
Representatives each. A description of Pfizer's current initial sales force
training program is described in Exhibit 2.5. Such program is subject to
revision from time to time by Pfizer, provided that the initial training
provided by Pfizer to Eyetech from time to time shall be the same as the initial
training that Pfizer contemporaneously provides to Pfizer's Sales
Representatives that Detail Products. Pfizer will provide ongoing training
relating to Products for the trainers of Eyetech's Sales Representatives. All
training programs for Eyetech's Sales Representatives other than the initial
sales and product training will be the responsibility of Eyetech, at its sole
expense; provided, however, that Pfizer will provide follow-up training for such
Eyetech Sales Representatives at Eyetech's reasonable request, provided that
Eyetech reimburses Pfizer for the reasonable costs and expenses incurred by
Pfizer in connection with such follow-up training. In order to coordinate the
training of Eyetech Sales Representatives with training of Pfizer Sales
Representatives, any training provided by Pfizer to Eyetech Sales
Representatives pursuant to this Section 2.5(a) shall take place at times and at
locations reasonably selected by Pfizer in consultation with Eyetech.

                  (b)      Pfizer and Eyetech shall, each at its own expense
(except as otherwise set forth in Section 2.5(a)), comply with any training plan
for the Products contained in the applicable Marketing Plan.

                  (c)      If a Party organizes Co-Promotion-related meetings of
its employees (such as periodic briefings of its Sales Representatives), it will
make reasonable efforts to keep the Product-related portions of such meetings
independent from other matters and to give the other Party advance notice of
such meetings. If requested by the other Party, the Party organizing such

                                       19

<PAGE>

meeting will permit Sales Representatives of the other Party to attend and
participate in such meetings or such portions thereof which relate to the
Co-Promotion of Products.

         2.6      Promotional Materials and Call Center Communications. The
Parties will only utilize promotional, advertising, communication and
educational materials relating to the Products in the US Territory (collectively
"Promotional Materials") and only conduct promotional activities for the
Products which, in each case, have been approved in the Marketing Plan or
otherwise by the CSC (as defined in Section 3.1). All Promotional Materials
shall name and feature both Parties with equal prominence. All promotional
activities conducted by the Parties shall be consistent with the Promotional
Materials so approved and the then-current Marketing Plan. Promptly after the
Effective Date, the Parties will mutually agree upon procedures whereby
designated representatives of each of them representing the marketing, medical,
regulatory and legal functions, will meet, whether in person, by telephone or by
videoconference, in order to discuss all promotional activities (except for
Detailing) and Promotional Materials prior to final approval thereof by the CSC.
In addition, as a prominent part of each communication with customers and other
third parties, the Call Center shall clearly identify the Products as joint
products of Eyetech and Pfizer. Eyetech shall own all rights to all Promotional
Materials, including all copyrights thereto, and Pfizer hereby assigns to
Eyetech all rights, title and interests of Pfizer in and to such Promotional
Materials, including without limitation all copyright interests of Pfizer
therein. Unless and until Promotional Materials are approved by the CSC for
publication or other general dissemination, each Party shall maintain them in
confidence pursuant to the terms of Article 11.

         2.7      Samples. The Parties, through the CSC, shall determine whether
it is necessary and appropriate to undertake a sampling program for the first
Product and, if so, the appropriate

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<PAGE>

terms and allocation of responsibilities for satisfying such sampling program;
provided that any samples will be allocated fairly between the Parties'
respective Sales Representatives in accordance with the Detailing arrangements
set forth in the Marketing Plan; and provided further that each Party shall be
responsible, at its sole expense, for (a) accounting for samples held, disposed
of or distributed by such Party or its Sales Representatives, (b) destroying and
disposing of samples after the latest date on which such samples are usable and
(c) complying with the requirements of all applicable Laws, including without
limitation the requirements of the Prescription Drug Marketing Act of 1987, as
amended.

         2.8      Distribution and Booking of Sales. Eyetech shall be
responsible for distribution, invoicing, credit and collection for the Products
in the US Territory. Eyetech will book all sales of Products in the US
Territory; provided that this Section 2.8 shall not be construed as an assurance
by Pfizer to Eyetech regarding the appropriate accounting treatment of such
sales.

         2.9      Contract Sales Forces. Without the consent of the other Party,
neither Pfizer nor Eyetech may use any contract sales force to Co-Promote or
Detail any Product.

         2.10     Delivery Technology Development Agreement. Promptly after the
Effective Date, the Parties shall in good faith discuss entering into a separate
agreement to provide for the development by the Parties of additional Product
delivery technology. The Parties intend to provide in such agreement for a
sharing between the Parties of the costs and benefits of developing and
commercializing such additional delivery technology on the same basis as
development costs and commercialization benefits are shared under this Agreement
and the License Agreement; provided that, for the avoidance of doubt, it is
agreed that neither Party would be required to make any upfront license fee
payments to the other Party in connection with such separate agreement.

                                       21

<PAGE>

                                    ARTICLE 3

                             MANAGEMENT OF ALLIANCE

         3.1      Committee/Subcommittees. In order to fulfill the objectives of
this Agreement, the Parties agree to establish a Joint Operating Committee
("JOC"), a Commercialization Subcommittee ("CSC"), a Clinical
Development/Regulatory Subcommittee ("CDRSC"), and a Manufacturing Subcommittee
("MSC"), and such other committees and subcommittees as may be established by
mutual consent of Eyetech and Pfizer. Each committee and subcommittee shall have
two co-chairpersons, one designated by each of Eyetech and Pfizer. All decisions
of the committees and subcommittees shall be by a vote of the co-chairpersons,
each co-chairperson having one vote, and all decisions shall be by unanimous
consent of the co-chairpersons.

         3.2      Meetings. The chairpersons of the JOC, CSC, CDRSC, MSC, or any
other committee or subcommittee, shall call meetings quarterly, or as otherwise
requested by one of the Parties. Meetings may be held in person, by telephone,
or by video conference call, and the location of each meeting shall alternate
between sites located in New York, New York selected by each co-chairperson.
Additional participants may be invited by any representative to attend meetings
where appropriate. The Parties shall cause their respective representatives on
the committees and subcommittees to use diligent efforts, acting in good faith,
to resolve all matters presented to them as expeditiously as possible.

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<PAGE>

         3.3      Clinical Development/Regulatory Subcommittee.

                  (a)      The CDRSC shall consist of research and development,
commercial, regulatory and marketing/medical managers (as needed) from each of
Eyetech and Pfizer, each of which shall confirm to the other its designees. The
CDRSC will establish a clinical development working group that shall be
responsible for:

                           (i)      Preparing annual Development Plans;

                           (ii)     Monitoring progress of all Product Studies
in the Territory (including reviewing costs and activities against the annual
Development Plan);

                           (iii)    Facilitating the exchange of all development
information and data relating to all Product Studies in the Territory;

                           (iv)     Review and approval of statistical analysis
plans and protocols for all Product Studies in the Territory and revising any
investigator's brochure(s); and

                           (v)      Providing updates on its activities and
achievements to the JOC.

                  (b)      The CDRSC will also establish a regulatory working
group that will be responsible for:

                           (i)      Overseeing, monitoring and coordinating all
regulatory (FDA) aspects of the US Territory Product Approval program, including
all US Territory regulatory actions, communications and filings (including
matters pertaining to Product labeling) and submissions (including filings and
submissions of supplements and amendments to FDA with respect to the Products);

                           (ii)     Establishing the schedule and implementation
strategy for all FDA filings;

                                       23

<PAGE>

                           (iii)    Coordinating preparation for and attendance
at FDA advisory committee meetings;

                           (iv)     Coordinating responses to additional FDA
requirements and FDA inquiries;

                           (v)      Proposing, overseeing and agreeing upon a
regulatory strategy and plan for obtaining regulatory approvals for the Products
in the Territory;

                           (vi)     Facilitating the exchange of all regulatory
information and data relating to Products in the Territory;

                           (vii)    Facilitating the exchange of information in
conjunction with Section 4.3 of this Agreement in order to ensure that
significant issues concerning adverse event information and safety issues are
addressed consistently among Governmental Authorities in the Territory; and

                           (viii)   Providing updates on its activities and
achievements to the JOC.

                  (c)      Neither Party shall make any change to any annual
Development Plan without the prior approval of the CDRSC, and all Development
Plans and Development Costs provided therein shall be consistent with the terms
of this Agreement. If the CDRSC is unable to reach a decision on any issue
within fifteen (15) Business Days after presentation, either Party may refer the
issue to the JOC for resolution.

                  (d)      Following a referral to the Senior Executives of the
Parties pursuant to Section 3.7 below, the final decision-making authorities set
out in Sections 3.3 (e), (f), (g) and (h) shall apply.

                  (e)      [**] shall have the final decision-making authority
for matters relating to [**] for such Product [**] to such Product [**];
provided, however, that [**] shall have the final

                                       24

<PAGE>

decision-making authority as to [**], provided that [**]. For purposes of the
previous sentence, [**]; provided, however, that [**].

                  (f)      [**] shall have final decision-making authority with
respect to [**] the Parties shall [**]. Except as otherwise set forth in this
Agreement, [**] shall have final decision-making authority with respect to [**].

                  (g)      Notwithstanding the Parties' joint approval rights
set forth in Section 3.3(f), [**] may not prevent [**] from [**] for the
applicable Product, [**].

                  (h)      Subject to Pfizer's fulfillment of its obligations
under the Regulatory Services Agreement, which shall require Pfizer to perform
its obligations thereunder in a commercially reasonable manner, in the event
that Eyetech materially fails to discharge its regulatory obligations in the US
Territory in a commercially reasonable manner applying accepted pharmaceutical
industry standards, and in compliance with all Laws, and fails to cure such
failure following written notice thereof from Pfizer and a reasonable
opportunity to cure, then the final decision-making authority with respect to
[**] the Products [**] shall be transferred to Pfizer for the balance of the
Co-Promotion Term; provided that in the event that after such transfer (x)
Pfizer closes a Divestiture Transaction pursuant to Section 17.11 or (y)
materially fails to discharge its regulatory obligations in the US Territory in
a commercially reasonable manner applying accepted pharmaceutical industry
standards, and in compliance with all Laws, and fails to cure such failure
following written notice thereof from Eyetech and a reasonable opportunity to
cure, then the final decision-making authority with respect to [**] the Products
[**] shall thereafter be exercised jointly by the Parties for the balance of the
Co-Promotion Term.

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<PAGE>

         3.4      Commercialization Subcommittee.

                  (a)      The CSC shall consist of members from each of Eyetech
and Pfizer, each of which shall confirm to the other its designees. The CSC
shall be responsible with respect to the US Territory for:

                           (i)      Preparing and implementing annually the
Marketing Plan;

                           (ii)     Monitoring progress under and compliance
with the Marketing Plan;

                           (iii)    Coordinating with the CDRSC with respect to
regulatory issues and future Product development activities to be undertaken
pursuant to the Development Plans;

                           (iv)     Developing positioning and market strategies
consistent with the Marketing Plan, including decisions to seek or include any
new indication, formulation or usage for the Products, such as for life cycle
management;

                           (v)      Developing advertising material and
strategies and promotional materials for the Parties' Sales Representatives for
the Products, designing packaging, and planning and overseeing educational and
professional symposia and speaker and activity programs for the Products in the
US Territory;

                           (vi)     Providing updates on the CSC's activities
and achievements to the JOC; and

                           (vii)    Discussing the prices at which the Products
will be sold to unaffiliated third parties throughout the Territory.

                  (b)      Following a referral to the Senior Executives of the
Parties pursuant to Section 3.7 below, the final decision-making authorities set
out in Sections 3.4(c), (d) and (e) shall apply.

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<PAGE>

                  (c)      Subject to Sections 3.4(d), (e) and (f) below, Pfizer
shall have final decision-making authority with respect to [**]:

                           (i)  activities [**];

                           (ii) [**]

                           (iii) [**] the Products; and

                           (iv) [**], including [**],

                  (d) [**] shall have final decision-making authority with
respect to:

                           (i)  [**] Eyetech shall [**]; and

                           (ii) [**] Eyetech [**]

                  (e) The Parties shall mutually agree upon [**] Products [**]
covered by [**] shall have [**].

                  (f) Notwithstanding the provisions of Section 3.4(c), but
subject to the provisions of Section 3.4(g), in the event that Pfizer closes a
Divestiture Transaction pursuant to Section 17.11, the final decision-making
authority with respect to all US Territory marketing and other commercial
activities for the Products pursuant to this Section 3.4, [**] Eyetech [**]
pursuant to [**] shall thereafter be exercised jointly by the Parties for the
balance of the Co-Promotion Term.

                  (g)      All Marketing Plans shall be consistent with the
terms of this Agreement. If the CSC is unable to reach a decision on any issue
within fifteen (15) Business Days after presentation, either Party may refer the
issue to the JOC for resolution.

         3.5      Manufacturing Subcommittee.

                  (a)      The MSC shall consist of members from each of Eyetech
and Pfizer, each of which shall confirm to the other its designees. The MSC
shall be responsible for:

                           (i)      Overseeing manufacturing activities underway
as of the Effective Date, including formulation development, product
characterization studies, stability studies, and management of clinical supplies
of the Products;

                                       27

<PAGE>

                           (ii)     Overseeing the manufacturing of registration
batches of Product;

                           (iii)    Overseeing process development plans;

                           (iv)     Monitoring worldwide quality assurance
efforts and ensuring that all Products are manufactured in accordance with the
Parties' quality standards;

                           (v)      Overseeing supply relationships with any
third party manufacturers;

                           (vi)     Subject to Section 4.1(c), review of the CMC
section of the NDA for each Product, provided that the time period for reviewing
any such CMC section shall, notwithstanding the provisions of Section 4.1(c), be
thirty (30) days from the date on which Eyetech, through the CDRSC, provides
Pfizer with a draft of the NDA pursuant to Section 4.1(c);

                           (vii)    Overseeing manufacture of the Products;

                           (viii)   Reviewing and approving Specifications for
purposes of the NDA and for Launch;

                           (ix)     Commencing and overseeing any new
manufacturing activities, including Product manufacturing process validation
prior to NDA approval and any pre-approval inspection of the Product
manufacturing subcontractors;

                           (x)      Coordinating with the CSC and CDRSC as
appropriate;

                           (xi)     Preparation for FDA inspections and ensuring
adherence to compliance standards;

                           (xii)    Evaluating the forecasts provided in each
Marketing Plan as well as inventory levels for the Product and future logistic
strategies and capacity planning;

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<PAGE>

                           (xiii)   Reviewing quality-related issues concerning
the Product or any component thereof; and

                           (xiv)    Providing updates on the MSC's activities
and achievements to the JOC.

                  (b)      If the MSC is unable to reach a decision on any issue
within fifteen (15) Business Days after presentation, either Party may refer the
issue to the JOC for resolution. Following a referral to the Senior Executives
of the Parties pursuant to Section 3.7 below, [**]shall have final
decision-making authority with respect to [**]; provided that:

                           (i)      Pfizer shall [**] any agreement [**] entered
into [**] (ii) [**] Pfizer [**] and/or [**] that otherwise would [**], and
Pfizer [**] pursuant to this Section 3.5 [**],

                           (iii)    [**] Pfizer [**] pursuant to Section 17.11,
[**],

                           (iv)     [**] the Parties, and

              (v)    [**] all Products [**].

3.6 Joint Operating Committee.

                  (a)      The Joint Operating Committee ("JOC") shall consist
of an equal number of members from each of Eyetech and Pfizer. Each of Eyetech
and Pfizer shall confirm to the other its designees. At least one of Pfizer's
designees shall be the Vice President in Pfizer's Pharmaceuticals Group with
global responsibility for the therapeutic area covering the Products. The JOC
shall address all of the significant and strategic issues within the purview of
the various subcommittees, and shall be responsible for resolving any issues
referred by the subcommittees. The JOC will be presented with updates on the
activities and achievements of the subcommittees. All decisions of the JOC will
be unanimous votes of the co-chairpersons.

                                       29

<PAGE>

                  (b)      If the JOC is unable to resolve any issue within ten
(10) Business Days after presentation, either Party may refer the issue to the
Senior Executives for resolution pursuant to Section 3.7.

         3.7      Deadlocks. If for any reason the JOC cannot resolve any matter
properly referred to it, either Party may refer the matter to the Senior
Executives for resolution. If after discussing the matter in good faith and
attempting to find a mutually satisfactory resolution to the issue, the Senior
Executives fail to come to consensus within five (5) Business Days of the date
on which the matter is referred to the Senior Executives, the provisions of
Sections 3.3(d), 3.4(b), and 3.5(b), as applicable, shall apply and resolutions
reached through such provisions shall be binding on the Parties; provided that
such decisions are made in good faith and are consistent with the provisions of
this Agreement.

         3.8      Limitation on Decision-Making Authority. Notwithstanding
anything to the contrary, none of the committees or subcommittees contemplated
by this Article 3 nor any Senior Executive pursuant to this Article 3 shall be
entitled to determine any matters for which: (a) one or more of the Parties is
allocated decision-making authority elsewhere in this Agreement; or (b) such
determination would violate or permit the violation of any express provision of
this Agreement, including, without limitation, the provisions of Sections
3.3(f), 3.3(g), 3.3(h), 3.4(e) and 3.5(b) that provide explicitly for mutual or
joint decision-making; or (c) this Agreement provides that neither Party shall
have final decision-making authority or provides that a decision shall not be
made without the approval or consent of a particular Party.

                                       30

<PAGE>

                                   ARTICLE 4

                         CLINICAL AND REGULATORY MATTERS

         4.1      Clinical and Regulatory Matters in the US Territory. This
Section 4.1 shall apply to clinical and regulatory matters relating to Products
in the US Territory.

                  (a)      Subject to Section 3.3, [**]FDA for the Products [**]
for each of the Products.

                  (b)      All NDAs and Approvals within the US Territory
relating to the Products shall be the property of Eyetech and held in the name
of Eyetech or its designated Affiliates. Eyetech's designated representative
shall serve as the designated regulatory official for Products in the US
Territory for purposes of receiving communications from the FDA.

                  (c)      Eyetech will provide Pfizer with copies, which copies
may be in draft form, of the following submissions to the FDA through the CDRSC.
If reasonably practicable, Eyetech will provide Pfizer with such copies at least
fifteen (15) days prior to planned submission to the FDA by Eyetech, whereupon
Pfizer shall provide comments to Eyetech regarding such submission at least ten
(10) days prior to such planned submission, and, Eyetech shall reasonably
consider the comments given by Pfizer prior to making such submission:

                           (i)      all annual reports regarding a Product prior
to First Approval of such Product, including without limitation the annual
reports required under 21 C.F.R. 312.33 as it may be amended; and

                           (ii)     all other filings that are not subject to a
deadline imposed by the Act of less than twenty-one (21) days after discovery of
an event that triggers the filing requirement and that are not otherwise
required to be jointly agreed upon pursuant to Section 4.1(d).

                                       31

<PAGE>

                  (d)      Eyetech shall provide notice to Pfizer within two (2)
Business Days of discovery by Eyetech of any event that triggers an FDA filing
requirement that is subject to a deadline imposed by the Act of less than
twenty-one (21) days after the discovery of such an event. Eyetech shall
promptly provide copies of any correspondence or other submission subject to
this Section 4.1(d) to Pfizer, and the chairpersons of the CDRSC shall discuss
in good faith and on a timely basis determine the most effective and expeditious
means of responding to such FDA filing requirement.

                  (e)      Eyetech shall provide notice to Pfizer of any
additional FDA requirements which FDA may impose with respect to the First
Approval, (including without limitation, additional clinical studies) and of all
FDA inquiries requiring a response within two (2) Business Days of receipt
thereof by Eyetech. Eyetech will promptly provide Pfizer with copies of all
correspondence between Eyetech and FDA and copies of all FDA contact reports
produced by Eyetech.

                  (f)      In connection with Sections 4.1(a), (b) and (c)
above, Eyetech shall provide Pfizer with notice of all meetings, conferences,
and discussions (including without limitation, advisory committee meetings and
any other meeting of experts convened by FDA concerning any topic relevant to
the Products) scheduled with FDA concerning any pending NDA or other regulatory
matters relating to the Products within two (2) Business Days after Eyetech
receives notice of the scheduling of such meeting, conference, or discussion.
Pfizer shall be entitled to have reasonable representation present at all such
meetings. Eyetech and Pfizer, through the CDRSC, shall use reasonable efforts to
agree (subject to Section 3.3(f)(i) to the extent applicable) in advance on the
scheduling of such meetings and on the objectives to be

                                       32

<PAGE>

accomplished at such meetings, conferences, and discussions and the agenda for
the meetings, conferences, and discussions with FDA.

                  (g)      Each Party shall provide to the other Party, through
the CDRSC, on a timely basis copies of all material pre-clinical and clinical
data compiled in support of an NDA or other regulatory filings in the US
Territory with respect to the Products.

                  (h)      Any decision to initiate a recall or withdrawal of
Product in the US Territory shall be made by the CDRSC. Before the CDRSC
initiates a recall or withdrawal, and upon the request for a recall or
withdrawal by either Party, the Parties shall promptly and in good faith discuss
the reasons therefor. Under no circumstances shall either Party unreasonably
object to a recall or withdrawal requested by the other Party, and neither Party
shall have any right to object to a recall or withdrawal requested by the other
Party for failure of a Product to meet the Specifications, for material safety
concerns or for noncompliance with the Act. In the event of any recall or
withdrawal, Pfizer shall implement any necessary action, with assistance from
Eyetech as reasonably requested by Pfizer.

         4.2      Clinical and Regulatory Matters in the ROW Territory. This
Section 4.2 shall apply to clinical and regulatory matters relating to Products
in the ROW Territory.

                  (a)      After the Effective Date, Pfizer will assume sole
ownership, control of and responsibility for all regulatory filings in the ROW
Territory, and Eyetech shall cooperate with Pfizer in connection with such
filings as reasonably requested by Pfizer and at Pfizer's sole cost and expense.
Prior to Pfizer taking over responsibility for contracting with API Bulk Drug
Substance Supplier(s) and/or Fill and Finish Services Supplier(s) or performing,
either directly or through Affiliates, services that otherwise would be
performed by API Bulk Drug Substance Supplier(s) and/or Fill and Finish Services
Supplier(s) in accordance with Section 6.12, Eyetech

                                       33

<PAGE>

shall be responsible for providing Pfizer with Product samples for use in
connection with regulatory filings relating to Products in the ROW Territory at
Pfizer's sole cost and expense.

                  (b)      All regulatory approvals in the ROW Territory
relating to the Products shall be deemed the property of Pfizer and held in
Pfizer's or its Affiliate's name.

                  (c)      Pfizer's rights under Sections 4.2(a) and (b) above
are subject to the following: Pfizer shall provide Eyetech with notice of all
meetings, conferences, and discussions (including without limitation, any
meeting of experts convened by regulatory authorities concerning any topic
relevant to the Products) scheduled with Governmental Authorities concerning any
material regulatory matters relating to the Products within two (2) Business
Days after the scheduling of such meeting, conference, or discussion. Eyetech
shall be entitled to have reasonable representation present at all such
meetings. In addition, with respect to clinical and regulatory matters in the
ROW Territory, Pfizer shall promptly provide Eyetech with (i) copies of all
pre-clinical and clinical data compiled in support of regulatory filings in the
ROW Territory, (ii) copies of all material regulatory correspondence with EMEA,
as defined in the License Agreement, (or any Governmental Authority in a Major
Country) and with Japanese Governmental Authorities, (iii) advance copies of
material submissions to EMEA (or any Governmental Authority in a Major Country)
and to Japanese Governmental Authorities, and the same opportunity to comment in
advance on such submissions (and to have its comments reasonably taken into
account) as Pfizer is provided with respect to the submissions to FDA under
Section 4.1(c), provided, however, that an inadvertent failure by Pfizer to
submit Eyetech advance copies pursuant to this Section 4.2(c)(iii) shall not be
considered a material breach of this Agreement if Pfizer has implemented
procedures reasonably designed to avoid any such failure and cures any such
failure promptly after its discovery, (iv) notices of any revocations of

                                       34

<PAGE>

Product marketing approvals and any Product recalls, and (v) reasonable
responses to inquiries by Eyetech regarding the regulatory approval and
commercialization processes for each Product in the ROW Territory, including
without limitation reasonable access to Pfizer personnel, documents and files in
connection with such inquiries.

         4.3      Inquiries, Adverse Events, etc.

                  (a)      Eyetech and Pfizer shall be responsible for the
surveillance, receipt, evaluation, and reporting of product complaints and
reports of adverse drug experiences, for the Products in the US Territory and
the ROW Territory, respectively; provided, however, during the term of the
Regulatory Services Agreement, Pfizer shall perform certain of such US Territory
responsibilities on behalf of Eyetech under the terms of the Regulatory Services
Agreement.

                  (b)      Eyetech shall be responsible for promptly
investigating Product complaints and reports of adverse drug experiences and
other required safety information (e.g., PSURs and annual safety reports)
associated with the use of any Product in the US Territory. As to each Product,
Eyetech shall submit reports of all adverse drug experiences associated with the
use of the Product(s) and other required safety information to the FDA in
accordance with applicable Law. Eyetech shall submit a copy of each such report
to Pfizer contemporaneously with its submission of the report to FDA, or in
advance of such submission if, and as, reasonably necessary to permit Pfizer to
comply with legal requirements applicable to it, if practicable.

                  (c)      Pfizer shall promptly investigate Product complaints
and reports of adverse drug experiences and other required safety information
(e.g., PSURs and annual safety reports) associated with the use of any Product
in the ROW Territory. As to each Product, Pfizer shall submit reports of all
adverse drug experiences associated with the use of the Product(s) and other
required safety information to the applicable Governmental Authorities in the
ROW

                                       35

<PAGE>

Territory in accordance with applicable Law. Pfizer shall submit a copy of each
such report to Eyetech contemporaneously with its submission of the report to
the applicable Governmental Authority in the ROW Territory, or in advance of
such submission if, and as, reasonably necessary to permit Eyetech to comply
with legal requirements applicable to it, if practicable.

                  (d)      Eyetech shall have the sole responsibility for
revising the Product labeling for the US Territory, and Pfizer for the ROW
Territory, as needed, to adequately warn of the potential risks identified by
reports of adverse drug experiences associated with the use of the Product and
from Product complaints. In addition, the Parties agree to jointly develop
additional written procedures including the mechanics for the surveillance,
receipt, evaluation, and reporting of Product complaints and adverse drug
experiences, including the possible maintenance of a worldwide safety database,
in accordance with this Article 4 and subject to the oversight of the CDRSC.

                  (e)      Each Party shall notify the other Party within two
(2) Business Days after it receives information about the initiation of any
investigation, review or inquiry by FDA or other Governmental Authority
concerning the distribution, promotion or sale of the Product, not otherwise
described above.

         4.4      Pfizer's Performance of Regulatory Services Agreement
Obligations. During the term of the Regulatory Services Agreement, all of
Eyetech's regulatory obligations under this Agreement are subject to Pfizer's
performance of its obligations under the Regulatory Services Agreement to the
extent Eyetech's performance of Eyetech's obligations depends on Pfizer's
performance of Pfizer's obligations under the Regulatory Services Agreement.

                                       36

<PAGE>

                                   ARTICLE 5

                               PRODUCT DEVELOPMENT

         5.1      Development Plan and Budget. The CDRSC shall develop an annual
development plan, which shall include preclinical and clinical plans and a
budget (a "Development Plan") in respect of the Products consistent with the
terms of this Agreement for each Year during the Co-Promotion Term. The CDRSC
shall meet to discuss the first Development Plan within ninety (90) days after
the Execution Date. A description of the overall development programs for
development of the AMD Product and DME Product is attached as Exhibit 5.1(a),
and a summary of the budgets for agreed upon Development Costs for such programs
(respectively, the "AMD Agreed Development Costs" and the "DME Agreed
Development Costs") are attached as Exhibit 5.1(b) to this Agreement. Each
annual Development Plan may be updated throughout the Year as deemed appropriate
by the CDRSC. Cumulative Development Costs for each of the AMD Product and DME
Product shall not exceed the AMD Agreed Development Costs and the DME Agreed
Development Costs, respectively, for such Products absent mutual consent of the
Parties. The Parties' respective obligations with respect to Development Costs
shall be as set forth in Section 8.1, provided that, unless otherwise agreed by
the Parties, neither Party shall be obligated to pay for any Development Costs
in excess of the AMD Agreed Development Costs or the DME Agreed Development
Costs, respectively, except to the extent a Party exercises its final
decision-making authority in accordance with Article 3 to approve such excess
Development Costs over the objection of the other Party or otherwise
unilaterally incurs such excess Development Costs, in which case the Party
exercising such final decision-making authority or unilaterally incurring excess
Development Costs shall be solely responsible for such excess Development Costs.
The Parties

                                       37

<PAGE>

acknowledge that the budgets set forth in Exhibit 5.1(b) do not cover
preclinical Development Costs for periods after the end of 2003 and do not cover
Development Costs for manufacturing process development and optimization. With
respect to such Development Costs not covered by the budgets set forth in
Exhibit 5.1(b), the Parties shall discuss reasonably necessary preclinical
Development Costs for subsequent periods and Development Costs for manufacturing
process development and optimization, and amend Exhibit 5.1(b) to cover such
additional Development Costs.

         5.2      AMD Product and DME Product Development. Each of the Parties
shall, during the Co-Promotion Term, use Commercially Reasonable Efforts to
develop and obtain Approvals for at least one AMD Product and one DME Product as
provided in this Agreement. In the event that a party fails to exercise such
Commercially Reasonable Efforts, such Party's sole liability and the other
Party's sole remedy for such failure shall be termination of this Agreement in
accordance with Section 13.2.

         5.3      Development of Products for Additional Indications in the
Field. At the request of either Party, the Parties shall in good faith meet and
discuss jointly developing Additional Developed Products where preclinical
and/or clinical results provide a reasonable basis for pursuing such additional
development or the pursuit of such additional development is otherwise
potentially commercially attractive. If the Parties agree to pursue such
additional development, the Parties shall amend the applicable Development
Plan(s) accordingly. If the Parties do not agree to pursue such additional
development, either Party shall have the right to pursue development of such
Additional Developed Products at its sole expense, subject to the other Party's
rights under this Agreement with respect to the Co-Promotion of Products
(including Additional Developed Products); provided, however, that such
additional development would

                                       38

<PAGE>

not, based on the best available scientific evidence, be reasonably likely to
have a materially adverse effect on the Co-Promotion of the Products.

                                   ARTICLE 6

                       LAUNCH, CO-PROMOTION AND DETAILING

         6.1      Co-Promotion of Products. Eyetech and Pfizer shall be jointly
responsible for the Co-Promotion of Products in the US Territory, with each
Party participating (except as otherwise expressly provided in this Agreement)
in all types of marketing activity in the US Territory. Each of the Parties
shall Co-Promote the Products in the US Territory during the Co-Promotion Term
in accordance with the terms of this Agreement and the applicable Marketing
Plan, and in compliance with all Laws. In conducting Co-Promotion activities,
each Party shall use Commercially Reasonable Efforts to Co-Promote the sale of
the Products in the US Territory. In the event that a Party fails to exercise
such Commercially Reasonable Efforts, such Party's sole liability and the other
Party's sole remedy for such failure shall be (a) termination of this Agreement
in accordance with Section 13.2 and (b) if applicable to such failure, the
remedies set forth in Section 6.5 below. All aspects of each Marketing Plan will
be determined pursuant to the committee system set forth in Article 3.

         6.2      Marketing Plan and Budget.

                  (a)      The CSC shall, subject to the provisions of Sections
3.4(c), (d), (e) and (f), develop a Marketing Plan (a "Marketing Plan") and a
marketing budget (a "Co-Promotion Budget") for the period from the Effective
Date through Launch of the first Product in the US Territory and for each Year
thereafter during the Co-Promotion Term consistent with Exhibit 6.2 and the
other terms of this Agreement. The first Marketing Plan shall be a pre-Launch
Marketing Plan, such Marketing Plan to be as approved by the JOC within six (6)
months of the

                                       39

<PAGE>

Effective Date (the "Pre-Launch Marketing Plan"). The Pre-Launch Marketing Plan
shall contain a pre-Launch Co-Promotion Budget covering the period of time from
the Effective Date through the Launch of the first Product in the US Territory
of up to $[**] or such higher amount as is agreed between the Parties. The
pre-Launch Co-Promotion Budget shall not exceed $[**] unless otherwise agreed by
both Parties, and neither Party's election to withhold such agreement shall be
subject to the other Party's decision-making authority. Neither Party shall
engage in any Co-Promotion activities except as provided in the applicable
Marketing Plan. Subsequent annual Marketing Plans will describe the plan for
commercialization of the Products in the US Territory, including: (a) general
strategies for the Detailing and marketing of the Products and allocation of
responsibilities for marketing activities; (b) Detail Requirements and sampling
activities, if any; (c) market and sales forecasts; (d) pricing and discounting
analysis; (e) advertising, public relations and other promotional programs,
including professional symposia and speaker and activity programs to be used in
the Co-Promotion of the Products; and (f) [**]. Each Marketing Plan and the
Co-Promotion Budget may, subject to the provisions of Sections 3.4(c), (d), (e)
and (f), be updated from time to time as deemed appropriate by the CSC.

                  (b)      Exhibit 5.1(b) also includes [**], which Product
Studies will be performed absent mutual agreement by the Parties to the
contrary. [**] these [**] of Products, [**].

         6.3      Detailing. The Parties shall be responsible for performing the
Detail Requirements specified in each then-current Marketing Plan.

         6.4      Detailing Reports. Each Party shall provide the other Party
and the CSC with a report as soon as practicable but in no event later than
forty-five (45) days following the end of each Quarter during the Co-Promotion
Term setting forth, in such detail and form as the Parties shall agree, the
number of Details made by such Party's Sales Representatives of Products in the

                                       40

<PAGE>

US Territory during such Quarter (each, a "Detailing Report"), provided,
however, that the Detailing Report for the fourth such Quarter in each Year
shall be cumulative and reflect the number of Details made by such Party's
respective Sales Representatives in the US Territory during such Year. Eyetech
covenants that it shall develop an internal system for the purpose of reporting
the number of Details of its Sales Representatives, and that it shall have such
system implemented by the time it begins Detailing the Products.

         6.5      Detail Shortfalls.

                  (a)      In the event that either Party fails to perform (such
Party, a "Shortfall Party") at least [**] percent ([**]%) of its Detail
Requirement in any Year as reported pursuant to Section 6.4 or verified pursuant
to Section 9.3, the Shortfall Party shall pay to the other Party as liquidated
damages an amount equal to the Detail Cost (as hereinafter defined), multiplied
by the applicable factor set forth below (the "Shortfall Factor") multiplied by
the total number of Details in the shortfall (the Detail Cost, multiplied by the
number of Details in the shortfall, multiplied by the Shortfall Factor, the
"Detail Shortfall Payment Amount"), on an incremental basis as set forth below:

                                       41

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
                                                                                Shortfall
                                            Detail Shortfall Level                Factor
-----------------------------------------------------------------------------------------
<S>                                       <C>                                   <C>
For such portion of shortfall which is: > or = [**]% but < [**]% of Detail         [**]
                                         Requirement
-----------------------------------------------------------------------------------------
For such portion of shortfall which is: > or = [**]% but < [**]% of Detail         [**]
                                         Requirement
-----------------------------------------------------------------------------------------
For such portion of shortfall which is: < [**]% of Detail Requirement              [**]
-----------------------------------------------------------------------------------------
</TABLE>

For purposes of this Section 6.5, "Detail Cost" means $[**]. If a Party wishes
to verify the Details performed by the other Party in any Year, such Party shall
give notice to the other Party that the notifying Party wishes to verify Details
pursuant to Section 9.3 within forty-five (45) days after receipt of the other
Party's last Detailing Report set forth in Section 6.4 for such Year.

                  (b)      With respect to any Year in which only one of the
Parties was a Shortfall Party, the Shortfall Party shall, within one-hundred
twenty (120) days after the end of such Year (or within thirty (30) days after
completion of any verification(s) of Details pursuant to Section 9.3 conducted
pursuant to Section 6.5(a) for such Year, if such verification(s) have not been
completed within ninety (90) days after the end of such Year), pay the Detail
Shortfall Payment Amount to the other Party.

                  (c)      With respect to any Year in which both Parties are
Shortfall Parties, the Party having performed the highest percentage of its
Detail Requirement in such Year (the "Highest Performing Party") shall be deemed
not to be a Shortfall Party and the percentage of such Party's Detail
Requirement performed by such Party shall be deemed to equal [**] percent
([**]%) of that Party's Detail Requirement in such Year. The other Party shall
continue to be required to pay a Detail Shortfall Payment Amount in accordance
with Section 6.5(b); provided, however, such Detail Shortfall Payment Amount to
be paid by such other Party shall be reduced

                                       42

<PAGE>

by (i) multiplying such other Party's Detail Requirement for such Year by the
percentage of the Highest Performing Party's Detail Requirement actually
performed by the Highest Performing Party during such Year and (ii)
recalculating such other Party's Detail Shortfall Payment Amount using the
reduced Detail Requirement for such other Party calculated in accordance with
the immediately preceding clause (i).

                  (d)      In the event that either Party fails to perform at
least [**] percent ([**]%) of its aggregate Detail Requirement (such Party, the
"Detail Breaching Party") for [**] during the Co-Promotion Term (a "Detail
Shortfall Period"), then:

                           (i)      If Pfizer is the Detail Breaching Party,
Eyetech shall have the right, in addition to the remedies provided for in
Sections 6.5(b) and 6.5(c) above, exercisable upon notice to Pfizer given within
ninety (90) days after the end of such Detail Shortfall Period (or within thirty
(30) days after completion of any verification of Pfizer's Details pursuant to
Section 9.3 conducted at Eyetech's request pursuant to Section 6.5(a) for such
Detail Shortfall Period, if such verification has not been completed within
sixty (60) days after the end of such Detail Shortfall Period), such notice to
be effective ninety (90) days after the date of such notice to Pfizer (or thirty
(30) days after completion of any verification of Pfizer's Details for such
Detail Shortfall Period requested by Eyetech, if later), to terminate this
Agreement; and

                           (ii)     If Eyetech is the Detail Breaching Party,
Pfizer shall have the right, in addition to the remedies provided for in
Sections 6.5(b) and 6.5(c) above, exercisable upon notice to Eyetech given
within ninety (90) days after the end of such Detail Shortfall Period (or within
thirty (30) days after completion of any verification of Eyetech's Details
pursuant to Section 9.3 conducted at Pfizer's request pursuant to Section 6.5(a)
for such Detail Shortfall Period, if such verification has not been completed
within sixty (60) days after the end of such

                                       43

<PAGE>

Detail Shortfall Period), such notice to be effective ninety (90) days after the
date of such notice to Eyetech (or thirty (30) days after completion of any
verification of Eyetech's Details for such Detail Shortfall Period requested by
Pfizer, if later), to elect to adjust, for the balance of the Co-Promotion Term,
the percentage of Net Sales that Pfizer would be entitled to receive under
Section 8.6(a), and the percentage of costs and expenses included in the
calculation of net payment amounts in Section 8.6(c) for which Pfizer would be
responsible would be increased from [**] percent ([**]%) to [**] percent
([**]%), Eyetech's corresponding percentage would be decreased from [**]percent
([**]%) to [**] percent ([**]%) and Eyetech would not have any further Detailing
responsibilities under this Agreement (the "Elective Remedy"); and

                           (iii)    The Parties understand and agree that the
Detail Shortfall Payment Amount shall be paid as liquidated damages and not as a
penalty and that such sum represents a genuine pre-estimate of the loss the
Parties believe would be suffered as a result of Detail shortfalls. In the event
of any Detail shortfall under Section 6.5, the remedies and compensation as
provided herein shall govern, and neither Party shall have any further claim for
breach of this Agreement on account of such Detail shortfall; provided that
nothing in this sentence shall preclude either Party from using a Detail
shortfall as a basis for termination of this Agreement for breach by the other
Party of such other Party's obligations under Section 6.1; and provided that a
failure to give or election not to give a notice by a Party prior to a deadline
set forth in Section 6.5(d)(i) or 6.5(d)(ii) with respect to a Detail shortfall
during any Detail Shortfall Period shall not constitute a waiver by such Party
with respect to the remedies and compensation under this Section 6.5 with
respect to a Detail shortfall during any subsequent Detail Shortfall Period.

         6.6      Sales Force Responsibilities. Each Party shall be solely
responsible for all costs and expenses incurred in providing the personnel
necessary to provide the services to be

                                       44

<PAGE>

performed by it as described in this Article 6. During the Co-Promotion Term,
Pfizer shall, in a manner determined at Pfizer's sole reasonable discretion, (a)
maintain and support a professional sales force in the US Territory; and (b)
ensure that sales of the Product will constitute a factor in the variable
compensation of Pfizer's Sales Representatives.

         6.7      Product Information. During the Co-Promotion Term, each Party
will provide the other with all material information relevant to the Detailing
and promotion of the Product within a reasonable time after such information
becomes known to the Party, provided such information is not received under a
secrecy obligation.

         6.8      Orders. Eyetech shall, subject to Pfizer's performance of
Pfizer's obligations under the Distribution Agreement, process and fulfill all
orders for Products from customers in the US Territory. Except as otherwise
provided in the Distribution Agreement, in the event that an order for Products
from a customer in the US Territory is received by Pfizer, Pfizer shall promptly
forward such order to Eyetech for processing and fulfillment.

         6.9      Audit. The number of Details shall be subject to external
audit as provided in Article 9.

         6.10     Third Party Reports. From time to time during the term hereof
the CSC shall agree upon the third party reports (such as those from IMS), to
the extent permitted by such third party, which the Parties wish to receive in
connection with the Co-Promotion of the Products (and the determinations to be
made under Section 6.2 with respect to the Marketing Plan and Co-Promotion
Budgets). The expenses of such reports shall be Marketing Expenses.

         6.11     Medical Claims. Neither Party shall make any medical claim for
the Products beyond the scope of the relevant regulatory approval(s) then in
effect for the Products; provided that, both Parties may distribute any
information concerning the Products or their use, including

                                       45

<PAGE>

but not limited to scientific articles, reference publications, and healthcare
economic information, in accordance with applicable Laws and subject to the
oversight of the CSC.

         6.12     Manufacturing.

                  (a)      After the Effective Date, Eyetech shall use
commercially reasonable efforts to enter into an agreement with an API Bulk Drug
Substance Supplier to supply the Parties with a supply of the active
pharmaceutical ingredient for the Products in the Territory. The selection of
such API Bulk Drug Substance Supplier and the terms and conditions of the
agreement to be entered into with the API Bulk Drug Substance Supplier shall be
subject to approval by the MSC. In addition, prior to the Execution Date,
Eyetech entered into the agreements set forth in Exhibit 6.12(a) with respect to
the supply of Products for clinical trials, and such agreements are hereby
deemed approved by the MSC. [**] shall be responsible for day-to-day management
of such API Bulk Drug Substance Supplier on behalf of the Parties.

                  (b)      After the Effective Date, Eyetech shall also use
commercially reasonable efforts to enter into an agreement with a Fill and
Finish Services Supplier to provide fill and finish services for the Products in
the US Territory. The selection of such Fill and Finish Services Supplier and
the terms and conditions of the agreement to be entered into with the Fill and
Finish Services Supplier shall be subject to approval by the MSC. [**] shall be
responsible for day-to-day management of such Fill and Finish Services Supplier
on behalf of the Parties.

                  (c)      The MSC shall not take any action or direct Eyetech
to take any action that would result in a breach of any agreement set forth on
Exhibit 6.12(a), or of any agreement between Eyetech and an API Bulk Drug
Substance Supplier or between Eyetech and a Fill and Finish Services Supplier,
including without limitation any minimum purchase obligation or non-cancelable
order obligation, entered into by Eyetech and approved by the MSC.

                                       46

<PAGE>

                  (d)      Subject to the provisions of Sections 2.8 and
6.12(c), the MSC may decide to have Pfizer (i) enter into agreement(s) with API
Bulk Drug Substance Supplier(s) and/or Fill and Finish Services Supplier(s)
and/or (ii) supply active pharmaceutical ingredient and/or fill and finish
services for the Products, in either case to replace the agreement(s) referred
to in Sections 6.12(a) and/or 6.12(b) or to provide a second source of supply
for active pharmaceutical ingredient and/or fill and finish services for the
Products; provided that the terms and conditions of any such agreements or
arrangements involving Pfizer shall be subject to Eyetech's prior approval and,
if such agreements or arrangements involving Pfizer relate to the supply of
active pharmaceutical ingredient and/or fill and finish services for the
Products in the US Territory, such agreements or arrangements shall be entered
into pursuant to agreements between Eyetech and Pfizer for such supply on terms
to be mutually agreed by the Parties; provided further that any such agreements
or arrangements shall be structured so that Eyetech acquires and maintains title
to all inventory of Products supplied for sale in the US Territory. From and
after such time, if any, as responsibility for manufacturing the Products has
been transitioned to Pfizer, Pfizer shall use Commercially Reasonable Efforts to
manufacture and supply sufficient quantities of the Products to enable Eyetech
to respond on a timely basis to all customer demand for Product in the US
Territory.

                  (e)      During any period in which Eyetech is the contracting
Party with API Bulk Drug Substance Supplier(s), Eyetech shall supply active
pharmaceutical ingredient for the Products to be sold by Pfizer in the ROW
Territory in accordance with terms and conditions to be mutually agreed by the
Parties, including resale pricing from Eyetech to Pfizer equal to Eyetech's
Manufacturing Costs incurred in providing such supply. Such terms and conditions
shall provide for an equitable allocation of supply between the US Territory and
the ROW

                                       47

<PAGE>

Territory in the event that the supply of active pharmaceutical ingredient for
the Products at any time is not sufficient to meet worldwide demand, such
allocation to be based on the orders placed by the Parties during the six-month
period preceding the shortfall in supply or, if sales have not been made in both
the US Territory and the ROW Territory during such preceding six-month period,
on the Parties' reasonable sales forecasts for the period affected by such
shortfall. In addition, such terms and conditions shall impose on Pfizer all of
Eyetech's obligations to the API Bulk Drug Substance Supplier(s) with respect to
the active pharmaceutical bulk drug substance so supplied by Eyetech to Pfizer
for the ROW Territory, shall be structured so that Eyetech shall have no
obligations to such API Bulk Drug Substance Supplier(s) with respect to the
active pharmaceutical bulk drug substance so supplied by Eyetech to Pfizer for
the ROW Territory greater than Pfizer's obligations to Eyetech with respect to
the active pharmaceutical bulk drug substance so supplied by Eyetech to Pfizer
for the ROW Territory, and shall not require Eyetech to give any warranties or
otherwise assume any liability for the performance of the API Bulk Drug
Substance Supplier(s) or for any active pharmaceutical ingredient bulk drug
substance so supplied by Eyetech to Pfizer.

                  (f)      Following the Effective Date, Eyetech shall, at least
thirty (30) days prior to the commencement of each Quarter commencing prior to
the first Launch of a Product in the US Territory in which Eyetech anticipates
incurring Manufacturing Costs for pre-Launch inventory of Products intended for
sale in the US Territory, prepare and deliver to Pfizer a statement of such
Manufacturing Costs (the "Manufacturing Costs Statement") projected to be
incurred by Eyetech during such Quarter. Within fifteen (15) days after
Eyetech's delivery of such statement of projected pre-Launch inventory
Manufacturing Costs, Pfizer shall pay Eyetech [**] percent ([**]%) of such
projected Manufacturing Costs for inventory, projected for sale in

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the US Territory if the first Launch of a Product is expected to occur in the
US Territory and no substantially concurrent Launch of a Product in the ROW
Territory is expected. Each Manufacturing Costs Statement shall contain an
adjustment as necessary to reflect any variance between the projected
Manufacturing Costs included by Eyetech in prior Manufacturing Cost Statements
and Eyetech's actual Manufacturing Costs for pre-Launch inventory of Products
projected for sale in the US Territory. For the avoidance of doubt, Eyetech
shall not have any financial responsibility for Manufacturing Costs for any
inventory of Products projected for sale in the ROW Territory, and Pfizer shall
be solely responsible for making all necessary payments for any such inventory.
Notwithstanding the foregoing provisions of this Section 6.12(f), the first
Quarter for which the Parties shall provide the statements of projected
pre-Launch inventory Manufacturing Costs shall be the second Quarter of 2003,
and adjustments shall be included the Parties' first statements of such
projected Manufacturing Costs for any pre-Launch inventory Manufacturing Costs
incurred by the Parties between the Execution Date and the end of the first
Quarter of 2003 as if such Manufacturing Costs were variances over previously
projected pre-Launch inventory Manufacturing Costs.

                  (g)      In the event an API Bulk Drug Substance Supplier or
Fill and Finish Services Supplier requires that Eyetech pay for capital
expenditures required for the manufacture of the Products other than as part of
the per-unit purchase price of the Products, Pfizer shall pay [**] percent
([**]%) of such expenditures and Eyetech shall pay [**] percent ([**]%) of such
expenditures; provided that any agreement obligating Eyetech to pay for such
capital expenditures shall be subject to the approval of the MSC as set forth in
Sections 6.12(a) and 6.12(b). Pfizer shall reimburse Eyetech for Pfizer's share
of all such expenditures incurred by Eyetech within thirty (30) days after
receiving any invoice from Eyetech for such expenditures.

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<PAGE>

                  (h)      The Parties shall cooperate, through the MSC, to
obtain mutually agreeable second sources for the supply of active pharmaceutical
ingredient bulk drug substance and fill and finish services for the Products.
The Parties shall also cooperate, through the MSC, to optimize, or cause the API
Bulk Drug Substance Supplier(s) and/or Fill and Finish Services Supplier(s) to
optimize, the manufacturing process used to manufacture the Products in order to
achieve improved quality and efficiency.

                  (i)      Subject to the provisions of Sections 6.12(f) and
6.12(g), the Parties' respective obligations with respect to Manufacturing Costs
relating to Products manufactured for sale in the US Territory shall be as set
forth in Section 8.3.

         6.13     Customer Support. Eyetech will, subject to Pfizer's
performance of its obligations under the Distribution Agreement, be responsible
for distribution and invoicing of Products in the US Territory and providing
customer service representatives to handle customer inquiries and service
related to the Products. The number of these customer service representatives
will be sufficient to reasonably handle calls and inquiries related to the
Products. Such distribution, invoicing and customer service expenses shall be
Marketing Expenses.

                                   ARTICLE 7

                               PAYMENT PROVISIONS

         7.1      Payment Currency. All amounts due under this Agreement shall
be paid to the designated Party in United States dollars.

         7.2      Payments. All payments under this Agreement shall be made on
or before the due date by electronic transfer in immediately available funds to
the respective account designated in writing by each Party at least two (2)
Business Days before the payment is due. Pfizer shall notify Eyetech's
Treasurer, or such other Eyetech representative as Eyetech's treasurer shall

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designate in writing, by facsimile transmission as to the date and amount of any
payment that Pfizer shall make at least two (2) Business Days prior to such
transfer. Eyetech shall notify Pfizer's treasurer, or such other Pfizer
representative as Pfizer's treasurer shall designate in writing, by facsimile
transmission as to the date and amount of any payment that Eyetech shall make at
least two (2) Business Days prior to such transfer. All payments under this
Agreement shall bear interest from the date due until paid at a rate equal to
the prime rate of Citibank, NA as announced on the date such payment was due
plus three percent (3%), compounded on a calendar quarterly basis. In addition,
the Party liable for late payment shall reimburse the other Party for all
reasonable costs and expenses, including without limitation reasonable
attorneys' fees and legal expenses, incurred in the collection of late payments.

                                   ARTICLE 8

                        EXPENSE SHARING AND COMPENSATION

         8.1      Sharing of Development Costs.

                  (a)      Subject to Sections 8.1(b) and (c), Pfizer shall pay
seventy-five percent of all Development Costs and Eyetech shall pay twenty-five
percent (25%) of all Development Costs (including Development Costs incurred for
clinical studies performed to support regulatory filings in both the US
Territory and the ROW Territory).

                  (b)      Subject to Section 8.1(e), with respect to
Development Costs incurred for clinical studies performed solely to support a
regulatory filing, or solely as a condition of receiving regulatory approval, in
a country in the ROW Territory:

                           (i)      Pfizer shall pay ** and Eyetech shall pay
** of the first ** of such Development Costs; and

                           (ii)     Pfizer shall pay all of such Development
Costs in excess of xxx.

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<PAGE>
                  (c)      The Parties shall each pay fifty percent (50%) of
Development Costs incurred for clinical studies performed solely to support a
regulatory filing in the US Territory, or solely as a condition of receiving
regulatory approval in the US Territory.

                  (d)      Following the Effective Date, (i) Eyetech shall, at
least thirty (30) days prior to the commencement of each Quarter in which
Eyetech anticipates incurring Development Costs, prepare and deliver to Pfizer a
statement of Development Costs projected to be incurred by Eyetech during such
Quarter in accordance with Section 5.1 above and the annual Development Plan
applicable to such Quarter and (ii) Pfizer shall, at least thirty (30) days
prior to the commencement of each Quarter in which Pfizer anticipates incurring
Development Costs, prepare and deliver to Eyetech a statement of Development
Costs projected to be incurred by Pfizer during such Quarter in accordance with
Section 5.1 above and the annual Development Plan applicable to such Quarter.
Each Party shall include in such statement an adjustment for variances between
projected Development Costs included in prior such statements delivered by such
Party and actual Development Costs incurred by such Party in the periods covered
by such prior statements. After delivery by each Party of its statement of
projected Development Costs, Eyetech shall, at least fifteen (15) days prior to
the commencement of such Quarter, prepare and deliver to Pfizer a combined
statement of projected Development Costs to be incurred by both Parties for such
Quarter, which shall provide a net amount to be advanced by the Party projected
to incur less than its share of the combined Development Costs for such Quarter
to the Party projected to incur more than its share of such combined Development
Costs, such net amount to equal the difference between each Party's share of the
combined Development Costs for such Quarter as determined in accordance with
Sections 8.1(a), (b) and (c) and the Development Cost amount such Party is
projected to incur during such Quarter. Within fifteen (15) days after

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<PAGE>

Eyetech's delivery of such combined statement of projected Development Costs,
the Party required to advance the net amount reflected in such combined
statement shall pay the other Party such net amount. Notwithstanding the
foregoing provisions of this Section 8.1(e), the first Quarter for which the
Parties shall provide the statements of projected Development Costs shall be the
second Quarter of 2003, and adjustments shall be included the Parties' first
statements of projected Development Costs for any Development Costs incurred by
the Parties between December 1, 2002 and the end of the first Quarter of 2003 as
if such Development Costs were variances over previously projected Development
Costs.

                  (e)      For purposes of Section 8.1(b) above, a clinical
study shall not be treated as performed solely to support a regulatory filing in
one or more countries in the ROW Territory if such clinical study is also
performed to support a regulatory filing in the US Territory; provided, however,
that the mere fact that a clinical study performed to support a regulatory
filing in the ROW Territory is required to be filed with FDA (pursuant to FDA
regulations requiring that any clinical study conducted anywhere in the world be
filed with FDA regardless of whether such clinical study is performed as a
condition to receiving regulatory approval from FDA), does not in and of itself
mean that such clinical study is also performed to support a regulatory filing
in the US Territory.

         8.2      Responsibility for Regulatory Costs. [**] be responsible for
[**] of all Regulatory Costs. Such Regulatory Costs shall be reflected in the
Parties' Quarterly Expense Reports pursuant to Section 8.6(b). [**] shall be
solely responsible for all Out-of-Pocket Costs and other costs solely related to
making or supporting regulatory filings in the ROW Territory.

         8.3      Responsibility for Cost of Goods Sold. [**] be responsible for
[**] of all Cost of Goods Sold for Products sold in the US Territory. Such Cost
of Goods Sold shall be reflected in

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<PAGE>

the Parties' Quarterly Expense Reports pursuant to Section 8.6(b); provided that
Pfizer and Eyetech shall each receive a credit (the "Inventory Build Credit")
against the amount otherwise to be paid by it with respect to Cost of Goods Sold
pursuant to this Section 8.3 equal to the lesser of (a) its share of the Cost of
Goods Sold for such Quarter and (b) the previously un-credited portion of its
Funded Inventory Build Costs.

         8.4      Responsibility for Marketing Expenses. [**] responsible for
[**] of all Marketing Expenses for the Products in the US Territory. Such
Marketing Expenses shall be reflected in the Parties' Quarterly Expense Reports
pursuant to Section 8.6(b). Pfizer shall be solely responsible for all
Out-of-Pocket Costs and other costs solely related to the marketing and
promotion of Products in the ROW Territory. In the event that any Out-of-Pocket
Costs related to both the marketing and promotion of Products in the US
Territory and the marketing and promotion of Products in the ROW Territory are
incurred by either Party, the Parties shall in good faith discuss an equitable
sharing of such Out-of-Pocket Costs.

         8.5      Net Sales Reports. Subject to Pfizer's performance of its
obligations under the Distribution Agreement, Eyetech shall deliver
electronically to Pfizer daily (if practicable, but in any event not less than
weekly) a report of gross sales of the Products in the US Territory on a daily
(if practicable, but in any event not less than weekly) and Year-to-date basis.

         8.6      Quarterly Reconciliation of Net Sales and Expenses.

                  (a)      During the Co-Promotion Term and subject to the terms
and conditions hereof, Eyetech shall pay to Pfizer fifty percent (50%) of Net
Sales in the US Territory. Payments by Eyetech to Pfizer of such amounts shall
be made in accordance with the reconciliation procedures set forth below in this
Section 8.6.

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<PAGE>

                  (b)      Within thirty (30) days after the end of each Quarter
during the Co-Promotion Term, each Party shall provide the other Party with a
statement of the expenses described in Sections 8.2, 8.3 and 8.4 relating to the
Co-Promotion of Products, if any, incurred by such Party during such Quarter, as
well as the details of any adjustments to be made to the amounts submitted by
such Party for previous Quarters (such reports, "Quarterly Expense Reports").
The Quarterly Expense Reports shall be in a form to be mutually agreed by the
Parties within ninety (90) days after the Execution Date.

                  (c)      Within forty (40) days after the end of each Quarter
during the Co-Promotion Term, Eyetech shall prepare and deliver to Pfizer a
report setting forth (i) the Net Sales of the Products in the US Territory
during said Quarter, (ii) adjustments (including reimbursements or recoupment of
prior deductions), if any, to Net Sales reported for any previous Quarter, (iii)
each Party's share of the amounts set forth in the Quarterly Expense Reports for
such Quarter, (iv) a calculation of the net amount payable and the Party owing
such net amount after subtracting each Party's share of the amounts set forth in
the Quarterly Expense Reports from each Party's share of Net Sales for such
Quarter and (v) a statement of the net amount payable and the Party owing such
net amount based on the foregoing calculation. The report prepared and delivered
by Eyetech pursuant to this Section 8.6(c) shall be in a form to be mutually
agreed by the Parties within ninety (90) days after the Execution Date.
Notwithstanding the foregoing provisions of Section 8.6(b) and this Section
8.6(c), the first Quarter for which the Parties shall provide Quarterly Expense
Reports and for which Eyetech shall provide a report pursuant to this Section
8.6(c) shall be the second Quarter of 2003, and adjustments shall be included in
the Parties' first Quarterly Expense Reports for any Regulatory Costs, Cost of
Goods Sold and Marketing Expenses incurred by the Parties between the

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<PAGE>

Execution Date and the end of the first Quarter of 2003 as if such costs and
expenses were adjustments to be made to amounts previously reported in Quarterly
Expense Reports.

                  (d)      The net amount payable, if any, as set forth in the
report prepared and delivered in accordance with Section 8.6(c) shall be paid by
the Party owing such net amount to the other Party within fifteen (15) days
after such report is delivered by Eyetech.

         8.7      Offset. Any amount payable by either Party pursuant to Section
8.6 may be offset against any other amounts then payable to such Party under
Section 8.1.

                                   ARTICLE 9

                             ACCOUNTING AND REPORTS

         9.1      Books and Records. Each Party shall keep comprehensive books
and records relating to this Agreement in accordance with GAAP. Such books and
records shall document all Detailing Reports and Net Sales, authorized expenses
incurred or paid and any other costs incurred (including Marketing Expenses,
Manufacturing Costs, third party royalty expenses, product liability and product
recall expenses and Development Costs) or revenues earned relating to this
Agreement and include all information subject to audit pursuant to Section 9.2.
All such books and records shall be maintained for three (3) Years following the
relevant Year or such longer period as is required by Law.

         9.2      Audits. These audit and adjustment provisions apply with
respect to all payments due from one Party to another pursuant to this
Agreement, including without limitation amounts payable pursuant to Article 8
and the number of Details performed under Section 6.4. Each Party shall have the
right to have the applicable books and records of the other Party audited by a
nationally recognized independent certified public accountant, selected by a
Party (as to which firm the other Party has no reasonable objection), under
appropriate confidentiality provisions

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<PAGE>

reasonably acceptable to the accounting firm conducting the audit, for the sole
purpose of verifying the accuracy of all financial, accounting and numerical
information and calculations under this Agreement. Any such audit shall be
conducted no more than once each Year during the Co-Promotion Term, shall be
limited to payments due within the prior three (3) Years, and shall be conducted
upon at least thirty (30) days' advance notice during normal business hours and
in a manner that does not interfere unreasonably with the business of the
audited entity. The results of any such audit shall be delivered in writing to
each party. Any underpayment or overbilling determined by such audit shall
promptly be paid or refunded by the audited Party. If the audited Party has
underpaid or overbilled amounts due under this Agreement by more than five
percent (5%) over any reporting period, the audited Party shall also reimburse
the other Party for the cost of such audit (with the cost of the audit to be
paid by the auditing Party in all other cases), plus interest at the interest
rate set forth in Section 7.2, from the date of any such underpayment or
overpayment. If the audited party is shown to be a Shortfall Party, the
provisions of Section 6.5 of this Agreement shall control. Such accountants
shall not reveal to the party seeking verification the details of its review,
except insofar as is necessary to describe the underpayment, overbilling or
level of Details. Any dispute arising out of any audit conducted pursuant to
this Section 9.2 and any other dispute arising out of the Parties' respective
payment obligations under this Agreement shall be resolved through binding
arbitration in accordance with Article 15, and either party may submit such
dispute to such binding arbitration.

         9.3      Sales Force Efforts. For two (2) Years following each Year,
each Party shall keep records relating to Details made by its Sales
Representatives, and Detailing Reports, during or for such Year, including
sampling of the Products. Such records shall be available for inspection and
audit in accordance with Section 9.2 above to determine compliance with the
terms hereof.

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                                   ARTICLE 10

                    INTELLECTUAL PROPERTY RIGHTS AND LABELING

         10.1     Trademark and Corporate Logos.

                  (a)      Subject to the provisions of this Section 10.1, each
Party shall retain all right, title and interest in and to its respective
corporate name and logo.

                  (b)      In the Territory, the Products shall be promoted and
sold solely under the MACUGEN Trademark and shall use a trade dress mutually
agreed by the Parties that includes Pfizer's and Eyetech's logos; provided that,
on a country-by-country basis in the ROW Territory, the Parties may jointly
agree that Pfizer shall promote and sell the Products in the ROW Territory under
Trademarks other than the MACUGEN Trademark in accordance with Section 10.1(e).
In the Territory, subject to the requirements of Law, Eyetech and Pfizer shall
be identified and given equal exposure and prominence on all Product package
inserts, trade packages, packaging, samples, and promotional materials; provided
that Eyetech acknowledges that in the ROW Territory such identification of
Eyetech shall be as the licensor or developer of the Products; and provided,
further, that if Eyetech or Pfizer cannot be given equal exposure and prominence
on all Product package inserts, trade packages, packaging, samples, and
promotional materials in the Territory as a result of the requirements of Law,
then Eyetech or Pfizer, as the case may be, shall be given as close to equal
exposure and prominence as possible, consistent with applicable Law.

                  (c)      For the Co-Promotion Term, (i) Pfizer grants to
Eyetech the non-exclusive right, free of charge, to use the Pfizer name and logo
in the US Territory solely for the purpose of Co-Promotion of the Products in
accordance with the terms of this Agreement and (ii) Eyetech grants to Pfizer
the non-exclusive right, free of charge, to use the Eyetech name and logo and
the

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<PAGE>

Trademark(s) in the US Territory solely for the purpose of Co-Promotion of the
Products in accordance with the terms of this Agreement; provided that such
rights shall be exercised, and all Products bearing such names and/or logos
and/or such Trademark shall be manufactured, in accordance with the quality
standards established by the MSC.

                  (d)      For the Term (as defined in the License Agreement),
Eyetech grants to Pfizer the non-exclusive right, free of charge, to use the
Eyetech name and logo and the Trademark(s) in the ROW Territory solely for
purposes of marketing and promoting Products in the ROW Territory in accordance
with the License Agreement; provided that such right shall be exercised, and all
Products bearing such names and/or logos and/or such Trademark(s) shall be
manufactured, in accordance with the quality standards established by the MSC.

                  (e)      Eyetech shall remain the owner of the Eyetech name
and logo and the Trademark(s) and the goodwill pertaining thereto. Eyetech shall
be solely responsible for registering and maintaining the Trademark(s) in the
Territory and shall remain the owner thereof. Except as contemplated herein,
Eyetech shall have no rights in or to the Pfizer name or logo or the goodwill
pertaining thereto. Except as contemplated herein, Pfizer shall have no rights
in the Trademark(s) in the Territory or to the Eyetech name or logo, or the
goodwill pertaining thereto. It is the Parties' intention to utilize a single
trademark for the Product throughout the Territory. Accordingly, Pfizer agrees
to use the MACUGEN Trademark for the Products in the ROW Territory, provided,
however, if any Governmental Authority in the EMEA or Japan fails to approve
MACUGEN as the trademark for the Product, or if either Party reasonably
determines that use of the MACUGEN Trademark may violate the rights of any third
party in the ROW Territory, then the Parties shall jointly select an alternative
Trademark for the Product in the ROW Territory. In either event, Eyetech shall
be solely responsible for registering and

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<PAGE>

maintaining such alternative Trademark in the ROW Territory and shall be the
owner thereof. Pfizer shall not register or seek to register the MACUGEN
Trademark or any alternative Trademark selected by the Parties in any country of
the Territory. [**] responsible for [**] of the cost of registering and
maintaining the Trademark(s) in the US Territory and [**] shall be responsible
for [**] percent ([**]%) of the cost of registering and maintaining the
Trademark(s) in the ROW Territory. Eyetech shall include all such US Territory
costs in Eyetech's Quarterly Expense Reports pursuant to Section 8.6(b). Pfizer
shall reimburse Eyetech for all such ROW Territory costs incurred by Eyetech
within thirty (30) days after receiving any invoice from Eyetech for such costs.

                  (f)      Eyetech shall inform Pfizer promptly of any
infringement of or challenge to the Trademark(s) in the Territory, whether
actual or threatened, which comes to the notice of Eyetech. In respect of the
defense and infringement of the Trademark(s) in the ROW Territory, as between
Pfizer and Eyetech, Pfizer shall have the first right, at its sole cost and
expense, to bring suit and to take action against such infringer or challenger,
in which case Pfizer shall control the prosecution or defense of any such suit
or claim, including without limitation, the choice of counsel, and shall have
the exclusive right to settle or dispose of any such suit or claim. Eyetech
shall provide reasonable assistance and co-operation as Pfizer may reasonably
request, at Pfizer's sole cost and expense.

                  (g)      Pfizer shall inform Eyetech promptly of any
infringement of or challenge to the Trademark(s) in the Territory, in each case
whether actual or threatened, which comes to the notice of Pfizer. In respect of
the defense and infringement of the Trademark(s) in the US Territory, as between
Eyetech and Pfizer, Eyetech shall have the first right to bring suit and to take
action against such infringer or challenger, in which case Eyetech shall control
the

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<PAGE>

prosecution or defense of any such suit or claim, including without limitation,
the choice of counsel, and shall have the exclusive right to settle or dispose
of any such suit or claim. Pfizer shall provide reasonable assistance and
co-operation as Eyetech may reasonably request.

                  (h)      Notwithstanding anything to the contrary in Sections
10.1(f) and 10.1(g) above, if a Party fails to initiate a suit or take other
appropriate action that it has the initial right to initiate or take pursuant to
Section 10.1(f) or Section 10.1(g), as applicable, within ninety (90) days after
becoming aware of the basis for such suit or action, then the other Party may,
in its discretion, provide the Party having the initial right with written
notice of such other Party's intent to initiate a suit or take other appropriate
action. If such other Party provides such notice and the Party having the
initial right fails to initiate a suit or take such appropriate action within
thirty (30) days after receipt of such notice from the other Party, then the
other Party shall have the right to initiate a suit or take other appropriate
action that it believes is reasonably required to protect the intellectual
property rights at issue. The proceeds of any recovery, court award or
settlement of such action shall first be applied to reimburse the Parties for
the costs and expenses of such prosecution and the balance shall be paid, for
amounts relating to the US Territory, [**] percent ([**]%) to Pfizer and [**]
percent ([**]%) to Eyetech, and for amounts relating to the ROW Territory, [**]
percent ([**]%) to Pfizer and [**] percent ([**]%) to Eyetech.

         10.2     Copyrights and Proprietary Programs. Eyetech shall own all
copyrights relating to Promotional Materials developed for use in the US
Territory for the Products. Pfizer and Eyetech shall each retain all rights
including, without limitation, copyrights and trademarks, to all of their
respective existing programs and materials in all formats (print, video, audio,
digital, computer, etc.) regarding sales training, patient education and disease
management programs owned by each of them as of the Execution Date, as well as
any modifications each may develop

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<PAGE>

in the future which are not specific to the Product. Eyetech and Pfizer shall,
from time to time, endeavor to each notify the other as to the identity of such
existing programs and materials. In addition, all new programs regarding sales
training, patient education and disease management jointly developed by Eyetech
and Pfizer pursuant to this Agreement shall be jointly owned by Eyetech and
Pfizer, and each Party shall have the right to use and exploit such developed
programs freely without any need to obtain the consent of the other Party and
without any duty to account to the other Party for such use or exploitation.
Each Party hereby assigns to the other Party all rights, title and interests,
including all intellectual property rights, in and to such Promotional Materials
and programs as necessary to give effect to the provisions of this Section 10.2.

         10.3     Developments. All ideas, inventions, Know-How, writings, data
and technical information (whether patentable or copyrightable or not) arising
out of any development or Product Study of any AMD Product or DME Product,
whether such development or study is sponsored and/or conducted by Eyetech or
Pfizer or their respective Affiliates or any third party shall be owned by
Eyetech. Pfizer hereby assigns to Eyetech all rights, title and interests,
including all intellectual property rights, in and to such ideas, inventions,
Know-How, writings, data and technical information as necessary to give effect
to the provisions of this Section 10.3.

         10.4     Third Party Agreements. Subject to Pfizer's performance of its
material obligations under this Agreement and under the License Agreement with
respect to its exercise of rights sublicensed to Pfizer by Eyetech and with
respect to third party royalties payable by Pfizer, Eyetech covenants and agrees
with Pfizer that, except where a failure by Eyetech to comply with the following
would not have a material adverse effect on the Co-Promotion of the Products,
Eyetech: (a) shall not execute any amendment, modification or waiver of any of
the

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<PAGE>

licenses and agreements listed on Exhibit 10.4 ("Third Party Agreements")
without the prior written consent of Pfizer, (b) shall not make any election or
exercise any right or option (or omit to take any action) that would terminate
or relinquish in whole or in part any Third Party Agreement, (c) shall comply
with all of its obligations under the Third Party Agreements in all material
respects, (d) shall take such reasonable actions as shall be necessary to keep
in full force and effect the Third Party Agreements, and (e) shall give prompt
notice to Pfizer, together with a summary of outstanding issues if Pfizer so
requests and subject to any obligations of confidentiality owed by Eyetech to
the other parties to such Third Party Agreements, of any actual or alleged
defaults, breaches, violations, proposed amendments or proposed modifications
of, or any proposed waivers under, any of the Third Party Agreements by any of
the parties to the Third Party Agreements.

                                   ARTICLE 11

                            CONFIDENTIAL INFORMATION

         11.1     Treatment of Confidential Information. During the Co-Promotion
Term and for five (5) years after the expiration or termination of this
Agreement, each Party shall maintain Confidential Information (as defined in
Section 11.2) of the other Party in confidence, and shall not disclose, divulge
or otherwise communicate such Confidential Information to others (except for
agents and advisors under obligations of confidentiality) or use it for any
purpose other than in connection with the development, manufacture, marketing,
promotion, distribution or sale of the Products as provided in this Agreement,
and each Party agrees to exercise reasonable efforts to prevent and restrain the
unauthorized disclosure of such Confidential Information by any of its
directors, officers, employees, consultants, subcontractors, licensees or
agents, which reasonable

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efforts shall be at least as diligent as those generally used by such Party in
protecting its own confidential and proprietary information.

         11.2     Confidential Information. "Confidential Information" means all
trade secrets or other proprietary information, including without limitation any
proprietary data and materials (whether or not patentable or protectable as a
trade secret), regarding a Party's technology, products, business or objectives
or regarding the Products, which is disclosed by a Party to the other Party. All
information disclosed prior to the Effective Date by Eyetech to Pfizer under or
pursuant to the confidentiality agreement between the Parties dated as of April
22, 2002, as amended, shall be deemed "Confidential Information" of Eyetech.
Notwithstanding the foregoing, there shall be excluded from the foregoing
definition of Confidential Information any of the foregoing that:

                  (a)      was known by the receiving Party prior to its date of
disclosure to the receiving Party as shown by the receiving Party's written
records; or

                  (b)      either before or after the date of the disclosure to
the receiving Party is lawfully disclosed to the receiving Party by third
parties not in violation of any obligation to the other Party; or

                  (c)      either before or after the date of the disclosure to
the receiving Party becomes published or generally known to the public through
no fault or omission on the part of the receiving Party or its Affiliates; or

                  (d)      is independently developed by or for the receiving
Party without reference to or reliance upon the Confidential Information as
demonstrated by contemporaneous written records of the receiving Party; or

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                  (e)      is required to be disclosed by the receiving Party to
comply with applicable Laws, to defend or prosecute litigation or to comply with
governmental regulations or the regulations or requirements of any stock
exchange or Nasdaq, provided that the receiving Party provides prior notice of
such disclosure to the other Party and takes reasonable and lawful actions to
avoid and/or minimize the degree of such disclosure.

                                   ARTICLE 12

                 REPRESENTATIONS, WARRANTIES AND INDEMNIFICATION

         12.1     Eyetech's Representations. Eyetech hereby represents and
warrants as of the date hereof as follows:

                  (a)      Eyetech has the corporate power and authority to
execute and deliver this Agreement and to perform its obligations hereunder, and
the execution, delivery and performance of this Agreement has been duly and
validly authorized and approved by proper corporate action on the part of
Eyetech, and Eyetech has taken all other action required by law, its certificate
of incorporation or by-laws or any agreement to which it is a party or by which
it or its assets are bound required to authorize such execution, delivery and
(subject to obtaining all necessary governmental approvals with respect to the
manufacture, use, sale, offer for sale, or importation of Products and subject
to any necessary HSR Clearance) performance. Assuming due authorization,
execution and delivery on the part of Pfizer, this Agreement constitutes a
legal, valid and binding obligation of Eyetech, enforceable against Eyetech in
accordance with its terms.

                  (b)      All manufacturing operations conducted by Eyetech (or
by third parties on its behalf) relating to the manufacturing of the Products
are being conducted in material

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compliance with applicable requirements and standards of any Governmental
Authority in the jurisdiction(s) in which such manufacturing is being conducted.

                  (c)      The representations and warranties of Eyetech
contained in the License Agreement are true and correct in all respects.

                  (d)      Eyetech has disclosed to Pfizer all material
information known to Eyetech relating to: (i) the drug quality, including
stability, variability, impurities and delivery performance in each case
relating to the Product, and (ii) changes made by Eyetech or its Affiliates
after the initiation of Phase III Clinical Trials for the Products relating to
formulation, packaging and method of manufacture and formulation and to
processing parameters, and (iii) the status of discussions with FDA or any
Governmental Authorities directly relating thereto, and (iv) clinical trial site
and contract research organization compliance with all provisions of the Act
governing clinical investigations, and (v) the safety and efficacy of the
Products.

         12.2     Pfizer's Representations. Pfizer hereby represents and
warrants as of the date hereof as follows:

                  (a)      Pfizer has the corporate power and authority to
execute and deliver this Agreement and to perform its obligations hereunder, and
the execution, delivery and performance of this Agreement has been duly and
validly authorized and approved by proper corporate action on the part of
Pfizer, and Pfizer has taken all other action required by law, its certificate
of incorporation or by-laws or any agreement to which it is a party or by which
it or its assets are bound required to authorize such execution, delivery and
(subject to obtaining all necessary governmental approvals with respect to the
manufacture, use, sale, offer for sale, or importation of Products and subject
to any necessary HSR Clearance) performance. Assuming due authorization,
execution and delivery on the part of Eyetech, this Agreement constitutes a

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legal, valid and binding obligation of Pfizer, enforceable against Pfizer in
accordance with its terms.

                  (b)      The representations and warranties of Pfizer
contained in the License Agreement are true and correct in all respects.

         12.3     No Warranties. EXCEPT AS OTHERWISE EXPRESSLY SET FORTH HEREIN,
THE PARTIES MAKE NO REPRESENTATIONS AND EXTEND NO WARRANTIES OF ANY KIND, EITHER
EXPRESS OR IMPLIED.

         12.4     General Indemnification in Favor of Pfizer.

                  (a)      Eyetech shall indemnify, defend and hold Pfizer
Parties (as hereinafter defined) harmless from and against any and all Losses
(as hereinafter defined) incurred, suffered or sustained by Pfizer Parties or to
which Pfizer Parties become subject, arising out of or resulting from:

                           (i)      any misrepresentation or breach of any
representation, warranty, covenant or agreement made by Eyetech in this
Agreement or the Other Product-Related Agreements; or

                           (ii)     any violation of the Act by Eyetech; or

                           (iii)    any third party claims, actions, suits,
proceedings, liabilities or obligations ("Third Party Claims") arising out of or
resulting from:

                                    (aa)     any misrepresentation or breach of
                  any representation, warranty, covenant or agreement made by
                  Eyetech in this Agreement or the Other Product-Related
                  Agreements; or

                                    (bb)     the manufacture, use or sale of a
                  Product, including without limitation all Third Party Claims
                  involving death or bodily injury caused or

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                  allegedly caused by the use of the Product (any all such
                  Losses, "Product Liability"), where Eyetech is the
                  manufacturer of Product (but not where Eyetech is the
                  contracting Party with API Bulk Drug Substance Supplier(s)
                  and/or Fill and Finish Services Supplier(s) pursuant to
                  Section 6.12) and where such Product fails to meet
                  Specifications or is not manufactured in accordance with GMP,
                  if applicable; or

                                    (cc)     the gross negligence, recklessness
                  or willful misconduct (other than as to Product Liability
                  matters) of Eyetech Parties in connection with Eyetech's
                  performance of this Agreement or the Other Product-Related
                  Agreements.

For purposes of this Article 12, "Pfizer Parties" means Pfizer and its
Affiliates and their respective agents, directors, officers and employees.

                  (b)      None of the indemnities in Section 12.4(a) shall
apply to the extent that any Loss is the result of any breach of this Agreement
or the Other Product-Related Agreements by Pfizer or of any gross negligence,
recklessness or willful misconduct of Pfizer Parties.

         12.5     General Indemnification in Favor of Eyetech.

                  (a)      Pfizer shall indemnify, defend and hold Eyetech
Parties (as hereinafter defined) harmless from and against any and all Losses
incurred, suffered or sustained by Eyetech Parties or to which Eyetech Parties
become subject, arising out of or resulting from:

                           (i)      any misrepresentation or breach of any
representation, warranty, covenant or agreement made by Pfizer in this Agreement
or the Other Product-Related Agreements; or

                           (ii)     any violation of the Act by Pfizer; or

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                           (iii)    any Third Party Claims arising out of or
                  resulting from:

                                    (aa)     any misrepresentation or breach of
                  any representation, warranty, covenant or agreement made by
                  Pfizer in this Agreement or the Other Product-Related
                  Agreements; or

                                    (bb)     Product Liability, where Pfizer is
                  the manufacturer of Product (but not where Pfizer is the
                  contracting Party with API Bulk Drug Substance Supplier(s)
                  and/or Fill and Finish Services Supplier(s) pursuant to
                  Section 6.12) and where such Product fails to meet
                  Specifications or is not manufactured in accordance with GMP,
                  if applicable; or

                                    (cc)     the gross negligence, recklessness
                  or willful misconduct (other than as to Product Liability
                  matters) of Pfizer Parties in connection with Pfizer's
                  performance of this Agreement or the Other Product-Related
                  Agreements.

For purposes of this Article 12, "Eyetech Parties" means Eyetech and its
Affiliates and their respective agents, directors, officers and employees.

                  (b)      None of the indemnities in Section 12.5(a) shall
apply to the extent that any Loss is the result of any breach of this Agreement
or the Other Product-Related Agreements by Eyetech or of any gross negligence,
recklessness or willful misconduct of Eyetech Parties.

         12.6     Product Liability and Intellectual Property Infringement
Indemnification.

                  (a)      Product Liability.

                           (i)      US Territory. Eyetech shall indemnify,
defend and hold the Pfizer Parties harmless from and against [**] percent
([**]%) of the amount of any and all Losses arising out of or resulting from any
Third Party Claim involving Product Liability in the US

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Territory (other than Product Liability Losses for which one Party is obligated
to indemnify the other Party pursuant to Section 12.4 or 12.5); Pfizer shall
indemnify, defend and hold the Eyetech Parties harmless from and against [**]
percent ([**]%) of the amount of any and all Losses arising out of or resulting
from any Third Party Claim involving Product Liability in the US Territory
(other than Product Liability Losses for which one Party is obligated to
indemnify the other Party pursuant to Section 12.4 or 12.5).

                           (ii)     ROW Territory. Pfizer shall indemnify,
defend and hold Eyetech Parties harmless from and against [**] percent ([**]%)
of the amount of any and all Losses arising out of or resulting from any Third
Party Claim involving Product Liability in the ROW Territory (other than Product
Liability Losses for which Eyetech is obligated to indemnify Pfizer pursuant to
Section 12.4).

                           (iii)    Certain Product Liability Claims.
Notwithstanding Sections 12.6(a)(i) and 12.6(a)(ii) above, Eyetech shall
indemnify, defend and hold the Pfizer Parties harmless from and against [**]
percent ([**]%) of the amount of any and all Losses arising out of or resulting
from any Third Party Claims involving the Product Liability matters described in
Exhibit 12.6(a)(iii).

                  (b)      Intellectual Property Infringement.

                           (i)      US Territory. Eyetech shall indemnify,
defend and hold the Pfizer Parties harmless from and against [**] percent
([**]%) of the amount of any and all Losses arising out of or resulting from any
Third Party Claims involving any actual or alleged infringement of any
trademarks, patent rights or other intellectual property rights, or
misappropriation of trade secrets, of any Person in connection with the
manufacture, use, sale or importation of the Product in the US Territory or in
connection with the manufacture or use of

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the Product in the ROW Territory for subsequent importation and/or sale in the
US Territory (other than Losses for which one Party is obligated to indemnify
the other Party pursuant to Section 12.4 or 12.5 and other than Losses relating
to Products ultimately sold outside the US Territory, which are governed by
Section 12.6(b)(ii)); Pfizer shall indemnify, defend and hold the Eyetech
Parties harmless from and against [**] percent ([**]%) of the amount of any and
all Losses arising out of or resulting from any Third Party Claims involving any
actual or alleged infringement of any trademarks, patent rights or other
intellectual property rights, or misappropriation of trade secrets, of any
Person in connection with the manufacture, use, sale or importation of the
Product in the US Territory or in connection with the manufacture or use of the
Product in the ROW Territory for subsequent importation and/or sale in the US
Territory (other than Losses for which one Party is obligated to indemnify the
other Party pursuant to Section 12.4 or 12.5 and other than Losses relating to
Products ultimately sold outside the US Territory, which are governed by Section
12.6(b)(ii)).

                           (ii)     ROW Territory. Pfizer shall indemnify,
defend and hold the Eyetech Parties harmless from and against [**] percent
([**]%) of the amount of any and all Losses arising out of or resulting from any
Third Party Claims involving any actual or alleged infringement of any
trademarks, patent rights or other intellectual property rights, or
misappropriation of trade secrets, of any Person in connection with the
manufacture, use, sale or importation of the Product in the ROW Territory or in
connection with the manufacture or use of the Product in the US Territory for
subsequent importation and/or sale in the ROW Territory (other than Losses for
which Eyetech is obligated to indemnify Pfizer pursuant to Section 12.4 and
other than Losses relating to Products ultimately sold by Eyetech in the US
Territory, which are governed by Section 12.6(b)(i)).

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                           (iii)    Certain Third Party Intellectual Property.
Notwithstanding Sections 12.6(b)(i) and 12.6(b)(ii) above, Eyetech shall
indemnify, defend and hold the Pfizer Parties harmless from and against [**]
percent ([**]%) of the amount of any and all Losses arising out of or resulting
from any Third Party Claims based on the matters set forth in:

                           (A)      the letter from Harsha Murthy to Larry
                                    Miller dated December 17, 2002 in connection
                                    with the manufacture, use, sale or
                                    importation of Products in the Territory;
                                    provided that such indemnity shall not apply
                                    to (I) Losses for which Pfizer is obligated
                                    to indemnify Eyetech pursuant to Section
                                    12.5, (II) Losses arising out of Third Party
                                    Claims [**] such Losses or (III) royalties
                                    or other amounts payable [**]; or

                           (B)      Exhibit 12.6(b)(iii)(B).

         12.7     "Losses". For purposes of this Article 12, "Losses" shall
mean, subject to Section 12.8, any and all (a) claims, losses, liabilities,
damages, fines, royalties, governmental penalties or punitive damages,
deficiencies, interest, awards, and judgments, and (b) with respect to third
parties, settlement amounts and all of the items referred to in clause (a) above
which, in accordance with Section 12.8, include third party special, indirect,
incidental, consequential damages (including without limitation lost profits)
and third party punitive and multiple damages, and (c) in connection with all of
the items referred in clauses (a) and (b) above, any and all costs and expenses
(including reasonable attorneys' fees and all other expenses reasonably incurred
in investigating, preparing or defending any litigation or proceeding, commenced
or threatened).

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         12.8     No Consequential or Punitive Damages.

                  (a)      NEITHER PARTY HERETO WILL BE LIABLE FOR INDIRECT,
INCIDENTAL, CONSEQUENTIAL, SPECIAL, EXEMPLARY OR PUNITIVE DAMAGES ARISING FROM
OR RELATING TO ANY BREACH OF THIS AGREEMENT, OR FOR LOST PROFITS ARISING FROM OR
RELATING TO ANY BREACH OF THIS AGREEMENT, REGARDLESS OF ANY NOTICE OF SUCH
DAMAGES. NOTHING IN THIS SECTION 12.8 IS INTENDED TO LIMIT OR RESTRICT THE
INDEMNIFICATION RIGHTS OR OBLIGATIONS OF EITHER PARTY UNDER THIS AGREEMENT WITH
RESPECT TO THIRD PARTY CLAIMS.

                  (b)      Notwithstanding anything to the contrary contained in
this Agreement, in the case of any claim by any Party alleging any breach of
this Agreement by the other Party, any payment obligation pursuant to Sections
8.1 and 8.6 of this Agreement (the "Payment Obligations"), will not be
considered as constituting special, incidental, indirect or consequential
damages under this Agreement (and, accordingly, nothing in Section 12.8(a) shall
prevent the recovery or inclusion of Payment Obligations in the definition of
"Losses").

         12.9     General Indemnification Procedures.

                  (a)      A Party seeking indemnification pursuant to this
Article 12 (an "Indemnified Party") shall give prompt notice to the Party from
whom such indemnification is sought (the "Indemnifying Party") of the
commencement or assertion of any Third Party Claim (which in no event includes
any claims by any Pfizer Parties or any Eyetech Parties) in respect of which
indemnity may be sought hereunder, shall give the Indemnifying Party such
information with respect thereto as the Indemnifying Party may reasonably
request, and shall not make any admission concerning such Third Party Claim,
unless such admission is required by applicable

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Law or legal process, including in response to questions presented in
depositions or interrogatories. Any admission made by the Indemnified Party,
except for an admission required by applicable Law or legal process, or the
failure to give such notice shall relieve the Indemnifying Party of any
liability hereunder only to the extent that the ability of the Indemnifying
Party to defend such Third Party Claim is prejudiced thereby. The Indemnifying
Party shall have the right, exercisable by written notice to the Indemnified
Party within thirty (30) days of receipt of notice from the Indemnified Party of
the commencement or assertion of a Third Party Claim, to assume and conduct the
defense of such Third Party Claim, with counsel selected by the Indemnifying
Party and reasonably acceptable to the Indemnified Party. The Indemnified Party
shall not settle such Third Party Claim within such thirty (30) day period.
Subject to the initial and continuing satisfaction of the terms and conditions
of this Article 12, the Indemnifying Party shall have full control of such Third
Party Claim, including settlement negotiations and any legal proceedings. If the
Indemnifying Party does not assume the defense of such Third Party Claim in
accordance with this Section 12.9, the Indemnified Party may defend the Third
Party Claim. If both Parties are Indemnifying Parties pursuant to
co-indemnification obligations under Section 12.6 with respect to the same Third
Party Claim, the Parties shall determine by mutual agreement, within twenty (20)
days following their receipt of notice of commencement or assertion of such
Third Party Claim (or such lesser period of time as may be required to properly
respond to such claim), which Party shall assume the lead role in the defense
thereof. Should the Parties be unable to mutually agree on which Party shall
assume the lead role in the defense of such Third Party Claim, both Parties
shall be entitled to participate in such defense through counsel of their
respective choosing; provided that in the case of any Third Party Claim with
respect to which (i) both Parties are Indemnifying Parties pursuant to
co-

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indemnification obligations under Section 12.6(b) and (ii) more than [**]
percent ([**]%) of the Products involved in the infringement or misappropriation
alleged in such Third Party Claim were sold or intended for sale in the ROW
Territory, Pfizer may defend the Third Party Claim in accordance with this
Section 12.9 (without giving effect to the immediately preceding sentence), but
may not enter into any settlement or consent to any judgment with respect to
such Third Party Claim without Eyetech's prior written consent if either (x)
such settlement or judgment would, taking into account the indemnification
provisions of Section 12.6(b), impose more than $[**] in liability on Eyetech or
(y) such settlement or judgment would, taking into account the indemnification
provisions of Section 12.6(b), impose more monetary liability on Eyetech than on
Pfizer or include non-monetary conditions with respect to Eyetech.

                  (b)      The Indemnifying Party or the Indemnified Party, as
the case may be, shall have the right to participate in (but not control), at
its own expense (subject to the immediately succeeding sentence), the defense of
any Third Party Claim which the other is defending as provided in this
Agreement. The Indemnifying Party shall not be liable for any litigation costs
or expenses incurred, without its consent, by the Indemnified Party where the
action or proceeding is under the control of the Indemnifying Party; provided,
however, that if the Indemnifying Party fails to take reasonable steps necessary
to defend such Third Party Claim, the Indemnified Party may assume its own
defense, and the Indemnifying Party will be liable for all reasonable costs or
expenses paid or incurred in connection therewith.

                  (c)      The Indemnifying Party, if it shall have assumed the
defense of any Third Party Claim as provided in this Agreement, shall not
consent to a settlement of, or the entry of any judgment arising from, any such
Third Party Claim to the extent such Third Party Claim involves equitable or
other non-monetary relief from the Indemnified Party. No Party shall,

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<PAGE>

without the prior written consent of the other Party, enter into any compromise
or settlement which commits the other Party to take, or to forbear to take, any
action.

                  (d)      Whether the Indemnifying Party chooses to defend or
prosecute any Third Party Claim, all the Parties hereto shall cooperate in the
defense or prosecution thereof and shall furnish such records, information and
testimony, and attend such conferences, discovery proceedings, hearings, trials
and appeals, as may be reasonably requested in connection therewith.

                  (e)      The Indemnified Party shall use commercially
reasonable efforts to pursue all rights and remedies available in order to
minimize the Losses for which indemnification is provided to the Indemnified
Party under this Article 12. Any indemnification hereunder shall be made net of
any insurance proceeds recovered by the Indemnified Party from unaffiliated
third parties; provided, however, that if, following the payment to the
Indemnified Party of any amount under this Article 12, such Indemnified Party
recovers any such insurance proceeds in respect of the claim for which such
indemnification payment was made, the Indemnified Party shall promptly pay an
amount equal to the amount of such proceeds (but not exceeding the amount of
such indemnification payment) to the Indemnifying Party.

                  (f)      The Parties agree and acknowledge that the provisions
of this Article 12 represent the Indemnified Party's exclusive recourse with
respect to any Losses for which indemnification is provided to the Indemnified
Party under this Article 12.

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                                   ARTICLE 13

                              TERM AND TERMINATION

         13.1     Term. This Agreement shall be effective as of the Effective
Date and shall continue in force until the expiration of the Co-Promotion Term,
unless sooner terminated as provided herein.

         13.2     Termination for Breach. Eyetech shall have the rights set
forth below in this Section 13.2 by notice to Pfizer, and Pfizer shall have the
rights set forth below in this Section 13.2 by notice to Eyetech.

                  (a)      Upon Eyetech's notice to Pfizer that a Material
Default by Pfizer has occurred, the Parties will meet to discuss in good faith
whether a plan to remedy the Material Default can be mutually agreed. If the
Parties fail to so agree within thirty (30) days after the date of such notice,
Section 13.2(b) below shall apply. Notwithstanding the foregoing provisions of
this Section 13.2(a), in the case of a payment default, the provisions of
Section 13.2(b) below shall apply without any obligation to meet to discuss
remedies pursuant to this Section 13.2(a).

                  (b)      Subject to the terms hereof, upon the occurrence of
any Material Default by Pfizer, Eyetech may, upon ninety (90) days prior written
notice, terminate this Agreement and the other Product-Related Agreements.
Eyetech may give the notice specified in this Section 13.2(b) concurrently with
the notice specified in Section 13.2(a) and shall not give the notice specified
in this Section 13.2(b) later than sixty (60) days after the date of the notice
specified in Section 13.2(a).

                  (c)      Upon Pfizer's notice to Eyetech that a Material
Default by Eyetech has occurred, the Parties will meet to discuss in good faith
whether a plan to remedy the Material Default can be mutually agreed. If the
Parties fail to so agree within thirty (30) days after the

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<PAGE>

date of such notice, Section 13.2 (d) below shall apply. Notwithstanding the
foregoing provisions of this Section 13.2(c), in the case of a payment default,
the provisions of Section 13.2(d) below shall apply without any obligation to
meet to discuss remedies pursuant to this Section 13.2(c).

                  (d)      Subject to the terms hereof, upon the occurrence of
any Material Default by Eyetech, Pfizer may, upon ninety (90) days prior notice,
terminate this Agreement and the other Product-Related Agreements. Pfizer may
give the notice specified in this Section 13.2(d) concurrently with the notice
specified in Section 13.2(c) and shall not give the notice specified in this
Section 13.2(d) later than sixty (60) days after the date of the notice
specified in Section 13.2(c).

                  (e)      "Material Default" means:

                           (i)      any default by any Party hereto of its
covenants, agreements or other performance obligations under this Agreement or
the License Agreement other than a payment default (which may include any one or
more defaults of any specific covenant, agreement or other performance
obligations contained herein) that, when aggregated with any other such uncured
defaults by such Party, is (x) material to this Agreement and the License
Agreement taken as a whole, and (y) shall have continued for thirty (30) days
after written notice thereof was provided to the alleged defaulting Party by the
non-defaulting Party (or, if such defaults cannot be cured within such 30-day
period, if the alleged defaulting Party does not promptly commence and
diligently continue all reasonable actions to cure such defaults during such
30-day period or does not cure in full such defaults within sixty (60) days
after written notice thereof was provided to the alleged defaulting Party); or

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                           (ii)     any default by any Party hereto of its
payment obligations hereunder that shall have continued for fifteen (15) days
after written notice thereof was provided to the alleged defaulting Party by the
non-defaulting Party; provided that, in the event of a good faith payment
dispute, such fifteen (15) day cure period shall be extended through the
fifteenth day following the date on which such dispute is resolved if the
alleged defaulting Party paid all undisputed amounts when due and provided the
non-defaulting Party with a reasonably detailed written explanation of the
alleged defaulting Party's basis for disputing the payment obligation within the
fifteen (15) day period following the written notice of the default by the
non-defaulting Party.

                  (f)      In the event of a Material Default by Eyetech
described in Section 13.2(c), Pfizer may, in its sole discretion, elect by
written notice to Eyetech of such election not later than sixty (60) days after
the date of the notice specified in Section 13.2(c), as an alternative to
terminating this Agreement and the other Product-Related Agreements, the
Elective Remedy.

         13.3     HSR Denial. Either Party may terminate all of the Transaction
Agreements effective upon notice to the other Party if the HSR Clearance Date
shall not have occurred on or prior to the date sixty (60) days after the
Parties make their respective HSR Filings pursuant to Section 16.1. In the event
of any termination pursuant to this Section 13.3, the Transaction Agreements,
including without limitation Section 13.9 of this Agreement, shall terminate;
provided, however, the confidentiality agreement between the Parties dated as of
April 22, 2002, as amended, shall remain in full force and effect
notwithstanding any termination of the Transaction Agreements in accordance with
this Section 13.3.

         13.4     Detail Shortfalls. Either Party may terminate this Agreement
as provided in Section 6.5.

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         13.5     Breach of Non-Competition obligations. If a Party breaches its
obligations under Section 14.1, the other Party may terminate this Agreement
upon thirty (30) days prior written notice of termination to the breaching
Party; provided that, if the breaching Party permanently ceases the activity or
eliminates the condition, as applicable, giving rise to the breach of its
obligations under Section 14.1 prior to the expiration of such thirty (30) day
notice period, such termination shall not take effect.

         13.6     Changes of Control. In the event of any Change in Control, the
Party subject to such Change of Control shall promptly notify the other Party of
such Change in Control, and the Party not subject to such Change of Control
shall have the right upon sixty (60) days notice, to terminate this Agreement
and the other Product-Related Agreements where the Acquiring Corporation has not
agreed to assume all obligations of an Affiliate of the Party subject to the
Change of Control under this Agreement and the License Agreement. In the event
of any Change in Control of Eyetech, Pfizer shall have the right upon one
hundred twenty (120) days notice, to terminate either or both of the Regulatory
Services Agreement and the Distribution Agreement. If the Change of Control of
Eyetech is an acquisition of Eyetech by a third party that, together with its
Affiliates, had annual revenues from the sale of prescription pharmaceutical
products in the US in excess of US$1 billion during its most recently reported
fiscal year, then the acquiring Person shall have the right upon one hundred
twenty (120) days written notice, to terminate either or both of the Regulatory
Services Agreement and the Distribution Agreement. In either event, each of
Pfizer or the acquiring Person must exercise its right of termination with six
(6) months of the date of such Change of Control.

         13.7     Termination of License Agreement. In the event that the
License Agreement is terminated or expires for any reason, either Party may, at
its option, terminate this Agreement and the other Product-Related Agreements
upon written notice of termination to the other Party.

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         13.8     Sales Threshold Termination. If, during the [**] period
commencing with the Year following the earlier of (a) the implementation of a
National Coverage Determination for the first Product from the United States
Department of Health and Human Services (Centers for Medicare and Medicaid
Services) and (b) the [**] of such Product in the US Territory, the Net Sales
in the US Territory for any [**] during such [**] period are less than [**],
for the [**], and such failure to achieve such Net Sales targets is not a
result of Eyetech's material breaches of its representations, warranties,
covenants and agreements contained in this Agreement and the License Agreement
(such failure to achieve Net Sales, the "Net Sales Failure"), then Eyetech may,
at any time within [**] following determination of Net Sales for the [**], elect
to terminate this Agreement upon 180 days notice to Pfizer; provided that such
termination shall be Eyetech's sole and exclusive remedy and Pfizer's sole and
exclusive liability in the event of termination by Eyetech pursuant to this
Section 13.8. In the event of any termination of this Agreement pursuant to this
Section 13.8, Eyetech shall thereafter pay to Pfizer (x) a royalty of [**]
percent ([**]%) of the first [**] of annual Net Sales in the US Territory and
(y) a royalty of [**] percent ([**]%) of annual Net Sales in the US Territory
[**], for each Year of the [**] Years of the Co-Promotion Term immediately
following such termination, as if this Agreement had not been terminated.

         13.9     Survival of obligations. Notwithstanding any termination or
expiration of this Agreement,

                  (a)      neither Party shall be relieved of any obligations
incurred prior to such termination or expiration, including without limitation
payment obligations accrued prior to such termination or expiration;

                  (b)      the obligations of the Parties with respect to
accounts and reports (Article 9), ownership of intellectual property (Article
10), the protection and nondisclosure of Confidential Information (Article 11),
dispute resolution (Article 15), indemnification (Sections 12.4, 12.5, 12.6,
12.7, 12.8 and 12.9), this Section 13.9 and non-competition (Section 14.1), as
well as any other provision of this Agreement which by its terms survives
termination or which is required to give effect to such termination or the
consequences of such termination, shall survive termination and remain in effect
in accordance with their respective terms;

                  (c)      If the License Agreement remains in effect after such
termination or expiration of this Agreement (a "License Survival Event"), the
provisions of this Agreement that relate to Products in the RoW Territory shall
survive such termination for so long as the License Agreement remains in effect.
If a License Survival Event takes place, the Parties recognize that adjustments
may need to be made to certain of such surviving provisions relating to Products
in the RoW Territory, such as the arrangements respecting the governance
provisions set forth in Article 3. Without limiting the foregoing, the Parties
acknowledge that the following rights shall survive termination or expiration of
this Agreement in the case of a License Survival Event: (a) the rights granted
to Pfizer in Sections 10.1 and 10.2 of this Agreement; (b) Eyetech's rights with

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respect to the MSC's responsibilities for ensuring that all Products are
manufactured in accordance with the Parties' quality standards pursuant to
Section 3.5; and (c) Eyetech's rights with respect to Pfizer's regulatory
activities in the RoW Territory pursuant to Section 4.2(c) of this Agreement.
After a License Survival Event, for so long as the License Agreement remains in
effect, Pfizer shall have rights with respect to Eyetech's regulatory activities
in the US Territory commensurate with the rights Eyetech has with respect to RoW
Territory regulatory matters under Section 4.2(c);

                  (d)      Pfizer's obligations under Section 8.1 with respect
to Development Costs during the following periods immediately following
termination shall survive any termination pursuant to Section 13.2 based on
Material Default(s) by Pfizer or any termination pursuant to Section 13.7: (i)
if such termination occurs prior to the first Launch of a Product in the US
Territory, twelve (12) months, (ii) if such termination occurs after the first
Launch of a Product in the US Territory but prior to the fifth anniversary of
such Launch, nine (9) months, and (iii) if such termination occurs after the
fifth anniversary of the first Launch of a Product in the US Territory, six (6)
months;

                  (e)      Pfizer shall promptly and in no event later than
sixty (60) days after termination or expiration (i) transfer to Eyetech
ownership of all governmental or regulatory filings and approvals (including all
INDs and NDAs (and their foreign equivalents)) relating to Products, (ii)
deliver to Eyetech all pre-clinical and clinical data and information in
Pfizer's possession or control relating to Products, (iii) deliver to Eyetech
copies of all reports, records, regulatory correspondence and other materials in
Pfizer's possession or control relating to the pre-clinical and clinical
development, regulatory approval, manufacture, distribution and sales of
Products, including without limitation all information contained in the
centralized global safety

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database established and maintained by Pfizer in accordance with the Regulatory
Services Agreement, and (iv) deliver to Eyetech all data and information
relating to process conditions, in-process controls, analytical methodology and
formulation, in each case as developed by Pfizer and relating to the
manufacturing of Products, solely for use in connection with the Products;

                  (f)      Pfizer shall grant to Eyetech a non-exclusive,
non-royalty-bearing, perpetual right and license under Pfizer's and its
Affiliates' rights in Collaboration Intellectual Property (as defined in the
License Agreement) to develop, make, have made, use, sell, offer for sale,
import, and have imported Products in the Territory;

                  (g)      if Pfizer has contracted with API Bulk Drug Substance
Supplier(s) or with Fill and Finish Services Supplier(s), or if Pfizer has taken
over responsibility for performing, either directly or through Affiliates,
services that otherwise would be performed by API Bulk Drug Substance
Supplier(s) and/or Fill and Finish Services Supplier(s), Pfizer shall continue
to manufacture or have manufactured (including filling and finishing of)
Products being manufactured by Pfizer and/or its Affiliates, on the terms and
conditions in effect immediately prior to the applicable notice of termination,
for worldwide supply to Eyetech during the shorter of (i) the twenty-four (24)
month period following termination and (ii) the period following termination and
prior to Eyetech's establishment of its own manufacturing capabilities and/or
third party manufacturing and supply arrangements with respect to the Products;
and Pfizer shall cooperate with Eyetech during such period to assign to Eyetech
all third party manufacturing and supply (including fill and finish services)
agreements and transfer to Eyetech all manufacturing know-how, and to provide
Eyetech with such other assistance as may be requested by Eyetech, reasonably
required by Eyetech for the purpose of establishing its own manufacturing

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capabilities and/or third party manufacturing and supply arrangements with
respect to the Products;

                  (h)      Pfizer shall permit Eyetech, at Eyetech's option, to
purchase, at Manufacturing Cost, all or any part of Pfizer's worldwide unsold
inventory of raw materials for Products, work-in-progress Products and finished
Products as of the effective date of termination, provided that, Pfizer shall
not be required to sell to Eyetech inventories of raw materials for Products and
work-in-progress Products that Pfizer needs to satisfy its obligations under
Section 13.9(g); and

                  (i)      unless this Agreement expressly provides that
termination shall be the sole and exclusive remedy for a particular breach
hereof, either Party's right to commence an action, suit or other proceeding
claiming breach of this Agreement by the other Party shall survive termination.

         Upon any termination of this Agreement, each Party shall promptly
return to the other Party all written Confidential Information, and all copies
thereof, of such other Party and Pfizer shall have no further right with respect
to, and shall cease all activities related to Co-Promotion of the Products.

                                   ARTICLE 14

                  NON-COMPETITION; DETAILING SERVICES AGREEMENT

         14.1     Non-Competition. During the Co-Promotion Term and during the
Term (as defined in the License Agreement), neither Pfizer nor Eyetech nor any
of their Affiliates shall, directly or indirectly, manufacture commercial
quantities of, or market, sell, detail or promote, any Competing Product in the
Territory (excluding the EU, as defined in the License Agreement), except for
the Products as provided in this Agreement and in the License

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Agreement. If (a) either Party terminates this Agreement pursuant to Section
13.2, 13.4 or 13.5 of this Agreement or (b) Pfizer terminates the License
Agreement pursuant to Section 10.1 of the License Agreement, then the
prohibition set forth in the immediately preceding sentence shall, in the case
of a termination described in clause (a) of this sentence, be extended with
respect to the other Party and its Affiliates through a period immediately
following the effective date of such termination of:

                           (i)      [**], if such termination occurs [**],

                           (ii)     [**], if such termination occurs [**], or

                           (iii)    [**], if such termination occurs [**],

and, in the case of a termination described in clause (b) of this sentence, be
extended with respect to Pfizer and its Affiliates through a period immediately
following the effective date of such termination of:

                           (i)      [**], if such termination occurs [**],

                           (ii)     [**], if such termination occurs [**], or

                           (iii)    [**], if such termination occurs [**].

Notwithstanding the foregoing, Eyetech and its Affiliates, either directly or in
collaboration with third parties, shall be entitled to commercialize products
that contain or are based on the Compound (as defined in the License Agreement)
for use outside the Field ("POF"), provided such products are sold under product
trademarks other than the Trademark(s) and are: (a) in a different dosage
strength; (b) in a different formulation; or (c) with a different delivery
system; in each case not intended or developed for use in the Field. Eyetech and
its Affiliates shall not conduct clinical trials or marketing studies with
respect to such POF to support use of such POF in the Field, and Eyetech and its
Affiliates shall require any third party collaborator to comply

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with this undertaking with respect to any POF. Subject to the provisions of
Section 14.2, any breach of this Section 14.1 shall entitle the non-breaching
Party to terminate this Agreement and the Other Product-Related Agreements
pursuant to Section 13.5.

         14.2     Acquisitions Involving Competing Products. Notwithstanding the
provisions of Section 14.1 above, if during the Co-Promotion Term Pfizer or
Eyetech or any of their respective Affiliates acquires or agrees to acquire a
Competing Product in the Territory through acquisition of or merger with a
company or entity, or is acquired or agrees to be acquired by a company or
entity that owns a Competing Product in the Territory, Pfizer or Eyetech, as
applicable, shall have thirty (30) days from the date of public announcement of
the acquisition or merger to notify the other Party as to whether Pfizer or
Eyetech or the acquiring company or entity, as applicable, intends to divest its
interest in such Competing Product. In the event that Pfizer or Eyetech or the
acquiring company or entity, as applicable, elects to divest its interest in
such Competing Product, such Party or the acquiring company or entity shall use
reasonable efforts to identify a third party purchaser to whom such Party or the
acquiring company or entity will divest its interest in such Competing Product
and to enter into a definitive agreement with such third party for such
divestiture as soon as reasonably practicable under the circumstances. If Pfizer
or Eyetech or the acquiring company or entity, as applicable, elects not to
divest its interest in such Competing Product or fails to divest its interest in
such Competing Product within [**] after the closing of the transaction for
which Pfizer or Eyetech, as applicable, has provided the other Party with
notice, then the other Party shall have the option, upon written notice to
Pfizer or Eyetech, as applicable, given no later than ninety (90) days after the
earlier of: (i) Pfizer's or Eyetech's written notice, as applicable, of its
election not to divest such Competing Product; and (ii) the end of such [**]
period described above, to terminate this Agreement and the Other Product-

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Related Agreements pursuant to Section 14.1, treating such election not to
divest or failure to divest such Competing Product as a breach of Section 14.1.
Notwithstanding the provisions of Section 14.1 and this Section 14.2, however,
neither Party shall have the right to terminate this Agreement and the Other
Product-Related Agreements based on the other Party's or its Affiliate's or
acquiring company's or entity's failure to divest its interest in a Competing
Product that is sold only in the EU (as defined in the License Agreement).

         14.3     Detailing Services Agreement; Additional Agreements.

                  (a)      The Detailing Services Agreement shall become
effective only upon the completion of the Pharmacia Merger.

                  (b)      The Parties shall in good faith undertake to identify
an additional Pfizer product for ophthalmic use and potential sale to retinal
specialists, in addition to the products covered by the Detailing Services
Agreement (an "Additional Pfizer Product"). If the Parties are able to identify
and mutually agree upon such Additional Pfizer Product, the Parties will attempt
to negotiate in good faith the terms and conditions of an agreement to allow
Eyetech to detail, co-develop or license such Additional Pfizer Product.

                  (c)      If for any reason (i) the Pharmacia Merger Agreement
is terminated or (ii) Pfizer determines that the Pharmacia Merger cannot be
closed, then, in either event, Pfizer and Eyetech will undertake in good faith
to identify a Pfizer product for ophthalmic use and sale to retinal specialists
to substitute for the products covered by the Detailing Services Agreement (a
"Substitute Product"). If the Parties are able to identify and mutually agree
upon such Substitute Product, the Parties will attempt to negotiate in good
faith the terms and conditions of an agreement to allow Eyetech to detail,
co-develop or license such Substitute Product.

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                  (d)      Notwithstanding the foregoing, neither Party is
obligated to enter into any agreement with the other pursuant to subsections
14.3(b) or 14.3(c). Accordingly, if the Parties are unable to enter into an
agreement respecting an Additional Pfizer Product or Substitute Product, Eyetech
shall have no rights to any such product, and Pfizer shall have no obligations
to Eyetech with respect to any such product or resulting from the Parties'
inability to enter into an agreement pursuant to subsections 14.3(b) or 14.3(c).

                                   ARTICLE 15

                               DISPUTE RESOLUTION

         15.1     Arbitration. Any payment dispute or dispute arising out of any
audit conducted pursuant to Section 9.2 shall be resolved through binding
arbitration as follows:

                  (a)      A Party may submit such dispute to arbitration by
notifying the other Party, in writing, of such dispute. Within thirty (30) days
after receipt of such notice, the Parties shall designate in writing a single
arbitrator to resolve the dispute; provided, however, that if the Parties cannot
agree on an arbitrator within such 30-day period, the arbitrator shall be
selected by the New York, New York office of the American Arbitration
Association (the "AAA"). The arbitrator shall be a lawyer knowledgeable and
experienced in the law concerning the subject matter of the dispute, and shall
not be an Affiliate, employee, consultant, officer, director or stockholder of
any Party.

                  (b)      Within thirty (30) days after the designation of the
arbitrator, the arbitrator and the Parties shall meet, at which time the Parties
shall be required to set forth in writing all disputed issues and a proposed
ruling on the merits of each such issue.

                  (c)      The arbitrator shall set a date for a hearing, which
shall be no later than thirty (30) days after the submission of written
proposals pursuant to Section 15.1(b), to discuss

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each of the issues identified by the Parties. The Parties shall have the right
to be represented by counsel. Except as provided herein, the arbitration shall
be governed by the Commercial Arbitration Rules of the AAA; provided, however,
that the Federal Rules of Evidence shall apply with regard to the admissibility
of evidence.

                  (d)      The arbitrator shall use his or her best efforts to
rule on each disputed issue within thirty (30) days after the completion of the
hearings described in Section 15.1(c). The determination of the arbitrator as to
the resolution of any dispute shall be binding and conclusive upon all Parties.
All rulings of the arbitrator shall be in writing and shall be delivered to the
Parties.

                  (e)      The (i) attorneys' fees of the Parties in any
arbitration, (ii) fees of the arbitrator and (iii) costs and expenses of the
arbitration shall be borne by the Parties as determined by the arbitrator.

                  (f)      Any arbitration pursuant to this Section 15.1 shall
be conducted in New York, New York. Any arbitration award may be entered in and
enforced by a court in accordance with Section 17.2.

         15.2     No Limitation. Nothing in Section 15.1 shall be construed as
limiting in any way the right of a Party to seek a temporary restraining order
or preliminary injunction with respect to any actual or threatened breach of
this Agreement from, or to bring an action in aid of arbitration in, a court in
accordance with Section 17.2. Should any Party seek a temporary restraining
order or preliminary injunction, then for purposes of determining whether to
grant such temporary restraining order or preliminary injunction, the dispute
underlying the request for such temporary restraining order or preliminary
injunction may be heard by a court in accordance with Section 17.2.

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                                   ARTICLE 16

                                   HSR MATTERS

         16.1     HSR Filings. Each of Eyetech and Pfizer shall as promptly as
possible and not later than January 22, 2003 file with the FTC and the Antitrust
Division of the DOJ, any HSR Filing required of it under the HSR Act with
respect to the transactions contemplated by the Transaction Agreements. The
Parties shall cooperate with one another to the extent necessary in the
preparation of any HSR Filing required to be filed under the HSR Act. Each Party
shall be responsible for its own costs, expenses, and filing fees associated
with any HSR Filing.

         16.2     HSR Cooperation; Further Assurances. Eyetech and Pfizer agree,
and shall cause each of their respective Affiliates, to cooperate and to use
their respective commercially reasonable efforts to obtain any HSR Clearance
required for the consummation of the transactions contemplated under the
Transaction Agreements and to respond to any government requests for information
under the HSR Act. The Parties will consult and cooperate with one another, and
consider in good faith the views of one another, in connection with any
analyses, appearances, presentations, memoranda, briefs, arguments, opinions and
proposals made or submitted by or on behalf of either Party in connection with
proceedings under or relating to the HSR Act. For the avoidance of doubt, it is
agreed that neither Party shall be obligated in any way to (a) sell, transfer or
otherwise dispose of (including without limitation by way on any "hold separate"
or similar arrangement) any asset or product or business, (b) terminate any
contractual relationship, or (c) amend, terminate or otherwise modify any
licenses or other intellectual property agreements, in order to obtain HSR
Clearance with respect to the transactions contemplated by the Transaction
Agreements.

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         16.3     Activities Prior to the Effective Date. The Parties shall not
engage in any of the activities contemplated by this Agreement and the Other
Product-Related Agreements, other than seeking to obtain HSR Clearance, prior to
the Effective Date.

                                   ARTICLE 17

                                  MISCELLANEOUS

         17.1     Governing Law. This Agreement shall be governed by and
interpreted in accordance with the internal laws of the State of New York,
without regard to its conflicts of laws rules.

         17.2     Jurisdiction. Except with respect to disputes arising out of
audits conducted pursuant to Section 9.2 or with respect to payment disputes,
which shall be resolved through binding arbitration in accordance with Article
15, each Party (a) irrevocably submits to the exclusive jurisdiction in the
United States District Court for the Southern District of New York and any State
courts sitting in New York, New York (collectively, the "Courts"), for purposes
of any action, suit or other proceeding arising out of this Agreement, and (b)
agrees not to raise any objection at any time to the laying or maintaining of
the venue of any such action, suit or proceeding in any of the Courts,
irrevocably waives any claim that such action, suit or other proceeding has been
brought in an inconvenient forum and further irrevocably waives the right to
object, with respect to such action, suit or other proceeding, that such Court
does not have any jurisdiction over such Party.

         17.3     Waiver. Waiver by a Party of a breach hereunder by the other
Party shall not be construed as a waiver of any succeeding breach of the same or
any other provision. No delay or omission by a Party to exercise or avail itself
of any right, power or privilege that it has or may have hereunder shall operate
as a waiver of any right, power or privilege by such Party. No

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waiver shall be effective unless made in writing with specific reference to the
relevant provision(s) of this Agreement and signed by a duly authorized
representative of the Party granting the waiver.

         17.4     Notices. All notices, instructions and other communications
hereunder or in connection herewith shall be in writing, shall be sent to the
address below and shall be: (a) delivered personally; (b) sent by registered or
certified mail, return receipt requested, postage prepaid; (c) sent via a
reputable nationwide overnight courier service; or (d) sent by facsimile
transmission. Any such notice, instruction or communication shall be deemed to
have been delivered upon receipt if delivered by hand, three (3) Business Days
after it is sent by registered or certified mail, return receipt requested,
postage prepaid, one (1) Business Day after it is sent via a reputable
nationwide overnight courier service, or when transmitted with electronic
confirmation of receipt, if transmitted by facsimile (if such transmission is on
a Business Day; otherwise, on the next Business Day following such
transmission).

Notices to Pfizer shall be addressed to:

              PFIZER INC.
              235 East 42nd Street
              New York, New York 10017-5755
              Telecopy: (212) 808-8652
              Attention: President, Pfizer Pharmaceutical Group

              with a copy to:

              PFIZER INC.
              235 East 42nd Street
              New York, New York 10017-5703
              Telecopy: (212) 808-8924
              Attention: Senior Vice President and General Counsel

Notices to Eyetech shall be addressed to:

              EYETECH PHARMACEUTICALS, INC.
              500 Seventh Avenue

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              18th Floor
              New York, New York 10018
              Telecopy: (212) 997-9251
              Attention: Chief Executive Officer

              with a copy to:

              Hale and Dorr LLP
              60 State Street
              Boston, Massachusetts 02109
              Telecopy: (617) 526-5000
              Attention: David E. Redlick, Esq.

Either Party may change its address by giving notice to the other Party in the
manner provided above.

         17.5     Entire Agreement. This Agreement (including Exhibits),
together with the Other Product-Related Agreements, contains the complete
understanding of the Parties with respect to the Parties' joint development and
commercialization of Products and supersedes all prior understandings and
writings relating to such subject matter. The Parties understand and agree that
this Agreement and the License Agreement are considered to be a single
integrated agreement and contain intellectual property rights and licenses
relating to the Products for which Pfizer has bargained and paid consideration.
If any applicable court of competent jurisdiction determines this Agreement
and/or the License Agreement to be executory in nature, such Transaction
Agreements shall be deemed to be, for purposes of Section 365(n) of the
Bankruptcy Code, licenses of rights to "intellectual property" as defined under
Section 101 of the Bankruptcy Code.

         17.6     Headings. Headings in this Agreement are for convenience of
reference only and shall not be considered in construing this Agreement.

         17.7     Severability. If any provision of this Agreement is held
unenforceable by a court or tribunal of competent jurisdiction because it is
invalid or conflicts with any law of any

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relevant jurisdiction, the validity of the remaining provisions shall not be
affected. In such event, the Parties shall negotiate a substitute provision
that, to the extent possible, accomplishes the original business purpose.

         17.8     Registration and Filing of the Agreement. To the extent, if
any, that a Party concludes in good faith that it is required to file or
register this Agreement or a notification thereof with any Governmental
Authority, including without limitation the US Securities and Exchange
Commission, or the US Federal Trade Commission, in accordance with applicable
Laws, such Party may do so. The other Party shall cooperate in such filing or
notification and shall execute all documents reasonably required in connection
therewith. In such situation, the Parties will request confidential treatment of
sensitive provisions of the Agreement, to the extent permitted by Law. The
Parties shall promptly inform each other as to the activities or inquiries of
any such Governmental Authority relating to this Agreement, and shall cooperate
to respond to any request for further information therefrom.

         17.9     Assignment. Except as otherwise provided herein, including
without limitation in Section 17.11, neither this Agreement nor any of the
rights or obligations hereunder may be assigned by either Party without the
prior consent of the other Party, except assignment, in whole or in part, to an
Affiliate of the assigning Party so long as such Affiliate agrees in writing to
be bound by the terms of this Agreement. The assigning Party shall remain
primarily liable hereunder notwithstanding any such assignment. Any attempted
assignment in violation hereof shall be void.

         17.10    Successors and Assigns. This Agreement shall be binding upon
and inure to the benefit of the Parties hereto and their
respective permitted successors and assigns.

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         17.11    Divestiture by Pfizer.

                  (a)      If (i) Pfizer enters into a definitive agreement to
acquire or merge with another company (the "Target") involving a purchase price
in excess of $[**] (which amount shall be increased on January 1 of each year to
reflect increases in the Consumer Price Index on each such January 1 over the
level of the Consumer Price Index on January 1, 2003), (ii) Pfizer reasonably
believes that a "Divestiture Requirement" exists, namely that the Governmental
Authorities with responsibility for antitrust or competition review and approval
of such acquisition or merger for either the United States or the EU, as defined
in the License Agreement (each an "Antitrust Authority" and, together, the
"Antitrust Authorities") will not grant the requisite clearance or approval for
the consummation of the acquisition or merger unless (x) Pfizer assigns,
sublicenses or otherwise transfers (any such assignment, sublicense or transfer,
a "Divestiture Transaction") Pfizer's rights and obligations under this
Agreement or the License Agreement to a non-Affiliate third party or (y) the
Target divests the business, product line or agreement(s) of the Target (the
"Target's Competitive Business") giving rise to the Divestiture Requirement,
(iii) Pfizer has used commercially reasonable efforts to avoid any requirement
of having to enter into a Divestiture Transaction, including without limitation
if reasonably practicable in Pfizer's good faith business judgment by
undertaking, or causing the Target to undertake, to the relevant Antitrust
Authorities to divest the Target's Competitive Business giving rise to the
antitrust or competition concern and (iv) the Target's Competitive Business
comprised less than [**] percent ([**]%) of the Target's revenues for the
Target's last fiscal year and less than [**] percent ([**]%) of the Target's
fair market value (as determined by Pfizer's Board of Directors in good faith
based on written advice and analysis of a nationally recognized investment
bank), Pfizer shall so notify Eyetech (a "Notice of Divestiture"), which Notice
of Divestiture shall include a detailed description of the Divestiture
Requirement, a certification to

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Eyetech by Pfizer of the accuracy of such description and a copy of the written
advice and analysis of the investment bank. Pfizer may not give more than one
Notice of Divestiture in any twenty-four (24) month period.

         17.11  (b)      If Pfizer gives a Notice of Divestiture, Eyetech may,
at its option (the "Acquisition Option"), elect to acquire Pfizer's rights under
this Agreement and the License Agreement by giving Pfizer notice of such
election (a "Preliminary Acquisition Notice") at any time within ten (10)
Business Days following the date of the Notice of Divestiture. If Eyetech
exercises its Acquisition Option, Pfizer shall promptly discuss with [**]
Eyetech [**] under this Agreement and the License Agreement and [**] referred to
in Section 17.11(c) [**] (as defined below) would be acceptable, with or without
[**] referred to in clause (i) of Section 17.11(d). Promptly after Eyetech gives
a Preliminary Acquisition Notice, the Parties will then jointly select an
investment bank to determine the fair market value of Pfizer's rights under this
Agreement and the License Agreement (the "FMV"). If the Parties are unable to
jointly select an investment bank within [**] Business Days after Eyetech gives
a Preliminary Acquisition Notice, the Parties shall select by a random drawing
an investment bank from among the top ten (10) investment banks from Thomson
Financial's then current listing of top financial advisors for worldwide
completed mergers and acquisitions or, if such directory is not then available,
from an alternative listing of investment banks for mergers and acquisitions to
be mutually agreed by the Parties, to determine the FMV. The investment bank
shall complete its valuation within [**] Business Days of its appointment, and
shall provide its results in writing to both Pfizer and Eyetech. The purchase
price to be paid by Eyetech to Pfizer shall be equal to [**] percent ([**] %) of
the FMV (the "Eyetech Purchase Price"). The results of the valuation shall be
binding on the Parties, and the fees of the investment bank shall be borne [**].

         (c)    If Eyetech wishes to acquire Pfizer's rights under this
Agreement and the License Agreement at the Eyetech Purchase Price, Eyetech shall
provide Pfizer with written notice (the "Confirmatory Acquisition Notice") to
that effect within [**] Business Days of the determination of the FMV; provided
that Eyetech may elect not to purchase Pfizer's rights under this Agreement and
the License Agreement, and if Eyetech does not provide Pfizer with a
Confirmatory Acquisition Notice within such [**] Business Day period after the
determination of FMV, Eyetech shall be deemed to have elected not to purchase
such rights. If Eyetech provides Pfizer with a Confirmatory Acquisition Notice
and [**] indicated that [**] of the [**], (i) Eyetech shall be required [**] of
the [**] at the time [**] between Eyetech and Pfizer, and (ii) Eyetech may [**];
provided that Eyetech may [**] and to [**]. If Eyetech provides Pfizer with a
Confirmatory Acquisition Notice and [**] indicated that such [**], then Eyetech
shall be [**] of the [**] at the time [**] between Eyetech and Pfizer. The
closing of the acquisition transaction shall not occur prior to the later of (x)
closing of Pfizer's acquisition of or merger with the Target and (y) [**] days
after the relevant Notice of Divestiture. Such acquisition transaction shall be
entered into pursuant to an acquisition agreement [**] to such [**], which
acquisition agreement shall contain [**] after the relevant Notice of
Divestiture; provided that such provision shall expire, and Eyetech's
obligations under such acquisition agreement shall no longer be [**], if Eyetech
does not provide Pfizer with a notice of [**] of such [**] within such [**] day
period.

         (d)    If [**] to the [**] referred to in Section 17.11(c), Eyetech
shall [**] to Pfizer [**]. The [**] shall: (i) be [**] to such [**], shall be
[**] by Eyetech in the [**] between Eyetech and Pfizer, and if [**] by Eyetech,
shall be [**] by such [**] as the Parties shall mutually agree, (ii) [**] at an
[**] based on [**] at the time of the transaction, (iii) be [**] (with Eyetech
having the [**] for any or all [**], which accrued interest shall compound and
be added to principal on the date of [**]), (iv) [**] of the date of issuance,
at which time [**] shall be [**], and (v[**] at any time [**].

         (e)    If Eyetech does [**] Pfizer with, [**], its Confirmatory
Acquisition Notice, or is [**] to be [**], then Pfizer may, concurrently with
the [**] with the Target, close a Divestiture Transaction with a [**] so long as
the [**] executes and delivers to Eyetech an agreement to be bound by this
Agreement and the License Agreement. [**] means [**] that is [**] in terms of
[**] in the calendar year most recently completed as of the date [**].

                  (f)      If (x) Pfizer consummates a Divestiture Transaction
or (y) Eyetech acquires Pfizer's rights under this Agreement and the License
Agreement pursuant to this Section 17.11, Pfizer shall, as requested by Eyetech,
either (i) subject to any necessary approval by the Antitrust Authorities,
maintain either or both of the Distribution Agreement and the Regulatory
Services Agreement in effect for such period of time, up to twelve (12) months
following the effective date of the Divestiture Transaction or acquisition by
Eyetech, as Eyetech may request, or (ii) terminate such agreements on the date
or dates specified by Eyetech.

         17.12    Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument.

         17.13    Force Majeure. No Party shall be liable for failure of or
delay in performing obligations set forth in this Agreement, and no Party shall
be deemed in breach of its obligations, if such failure or delay is due to
natural disasters or any causes reasonably beyond the control of such Party.

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         17.14    Non-Solicitation of Employees. During the Co-Promotion Term,
neither Party shall, directly or indirectly, recruit, or solicit any employee of
the other Party with whom such Party has come into contact or interacted for the
purposes of performing this Agreement, without the prior consent of the other
Party, except pursuant to general solicitations not targeted specifically at
such employees or in response to unsolicited employment inquiries by such
employees.

         17.15    Press Releases and Other Disclosures. The Parties hereby each
approve the form of joint press release set forth in Exhibit 17.15 hereto and
will cooperate in the release thereof as soon as practicable after the signature
of this Agreement by the Parties. The Parties also recognize that each Party may
from time to time desire to issue additional press releases and make other
public statements or disclosures regarding the subject matter of this Agreement.
In such event, the Party desiring to issue an additional press release or make a
public statement or disclosure shall provide the other Party with a copy of the
proposed press release, statement or disclosure for review and approval in
advance, which advance approval shall not be unreasonably withheld, conditioned
or delayed. No other public statement or disclosure concerning the existence or
terms of this Agreement shall be made, either directly or indirectly, by either
Party hereto, without first obtaining the written approval of the other Party.
Once any public statement or disclosure has been approved in accordance with
this Section, then either Party may appropriately communicate information
contained in such permitted statement or disclosure. Notwithstanding the
foregoing provisions of this Section 17.15 or of Article 11, a Party may (a)
disclose the existence and terms of the Transaction Agreements where required,
as reasonably determined by the disclosing Party, by applicable Law, by
applicable stock exchange or Nasdaq regulation or by order or other ruling of a
competent court, (b) disclose the existence

                                       97

<PAGE>

and terms of the Transaction Agreements under obligations of confidentiality to
agents, advisors, contractors, investors and sublicensees, and to potential
agents, advisors, contractors, investors and sublicensees, in connection with
such Party's activities hereunder and in connection with such Party's financing
activities and (c) publicly announce any of the matters set forth in Exhibit
17.15(c), provided that such announcements do not entail disclosure of
non-public technical or scientific information (which, for clarity, excludes
clinical trial results) and the announcing Party provides the other Party with a
copy of the proposed text of such announcement sufficiently in advance of the
scheduled release or publication thereof to afford such other Party a reasonable
opportunity to review and comment upon the proposed text.

         17.16    Third-Party Beneficiaries. None of the provisions of this
Agreement shall be for the benefit of or enforceable by any third party,
including, without limitation, any creditor of either Party. No such third party
shall obtain any right under any provision of this Agreement or shall by reason
of any such provision make any claim in respect of any debt, liability or
obligation (or otherwise) against either Party.

         17.17    Relationship of the Parties. Each Party shall bear its own
costs incurred in the performance of its obligations hereunder without charge or
expense to the other, except as expressly provided in this Agreement. Neither
Party shall have any responsibility for the hiring, termination or compensation
of the other Party's employees or for any employee compensation or benefits of
the other Party's employees. No employee or representative of a Party shall have
any authority to bind or obligate the other Party to this Agreement for any sum
or in any manner whatsoever, or to create or impose any contractual or other
liability on the other Party without said other Party's approval. For all
purposes, and notwithstanding any other provision of this Agreement to the
contrary, Pfizer's legal relationship under this Agreement to Eyetech shall be

                                       98

<PAGE>

that of independent contractor. Nothing in this Agreement shall be construed to
establish a relationship of partners or joint venturers between the Parties.

                                       99

<PAGE>

         17.18    Performance by Subsidiaries and Affiliates. To the extent that
this Agreement imposes obligations on Subsidiaries and Affiliates of a Party,
such Party agrees to cause its Subsidiaries and Affiliates to perform such
obligations.

         IN WITNESS WHEREOF, the Parties have signed this Agreement as of the
Execution Date.

PFIZER INC.                         EYETECH PHARMACEUTICALS, INC.

By:    /s/ Henry A. McKinnell       By:    /s/ David R. Guyer
       ______________________              ______________________

Name:  Henry A. McKinnell           Name:  David R. Guyer
       ______________________              ______________________

Title: Chairman and CEO             Title: CEO
       ______________________              ______________________

                                      100

<PAGE>

                                  EXHIBIT 1.20

                               GROUP/JOINT DETAILS

     Pfizer or Eyetech personnel, as the case may be, may make Product
presentations to medical professionals with prescribing authority in group
situations (each, a "Detailee"). Such presentations maybe be through speaker
programs, dinner and lunch programs, symposia, and other programs the nature of
which has been approved by the CSC.

[**] such a presentation will be considered [**]. It is understood that [**], as
the case may be, [**] For such group presentations conducted by either Eyetech
or Pfizer [**] conducting such presentation. [**] a group presentation, [**]
such a group presentation, [**] If, however, prior to such presentation, [**] It
is understood that for symposia and other group presentations [**] as provided
above. [**]

<PAGE>
                                  EXHIBIT 1.52

                                Call Center Costs

         For purposes of calculating Marketing Expenses, monthly Call Center
expenses shall equal the sum of:

         (i)      $[**]/month* multiplied by the number of full-time equivalent
                  Call Center Representatives (as defined below); and

         (ii)     Out-of-Pocket Costs paid by Pfizer for Call Center services
                  outsourced by Pfizer to non-employee third parties.

         A "Call Center Representative" shall mean a Pfizer employee whose
primary responsibility is to handle calls from or to Product-users, physicians
and other health care professionals, and managed care organizations concerning
questions about the Product and Product reimbursement, or a supervisor of any
such individual.

------------------------------------
* Adjusted annually, with the first such adjustment taking place for the first
full calendar year following the calendar year in which the Product is initially
Launched in the US Territory, according to changes in the Consumer Price Index
for All Urban Consumers (CPI U): U.S. city average, for the preceding Year.

                                      101
<PAGE>

                                   EXHIBIT 2.5

                          Sales Force Training Program

     The initial training Pfizer will offer to Eyetech field force
representatives will be Pfizer's typical training, i.e. "AS IS" program. [**]
various training phases [**]. Pfizer may also update the training program from
time to time. [**]

     [**] training time is [**] during the field time.

     The program includes training [**] subsequent training activities.

     Typical content covered during training consists of:

     -    [**]

     -    [**]

     -    [**]

     -    [**]

     -    [**]

     The program includes material [**]

     [**] appropriate training materials, [**] weeks prior to the training
program commencement. The training of Eyetech Sales Representatives will be
scheduled to coincide with regularly scheduled Pfizer training sessions.

     [**] These include (but are not limited to) topics such as the ones listed
below:

     -    [**]

     -    [**]

     -    [**]

     -    [**]

     -    [**]

     -    [**]

                                      102

<PAGE>

                                 EXHIBIT 3.4(d)

 Matters where Eyetech Possesses Special Expertise or has Special Relationships

                                      [**]

                                      103
<PAGE>

                                 EXHIBIT 3.4(e)

     -    [**]Objectives:

          -    Primary: [**].

     -    Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

          -    ESTIMATED COST: [**]

     -    [**] [**]Objectives:

          -    Primary: [**]

     -    Design:

     -    [**]NO-GO Criteria:

          -    [**].

     -    LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

ESTIMATED COST: [**]. [**].

     -    Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

INITIATION DATE: [**]DURATION: [**]ESTIMATED COST: [**]

                                       104

<PAGE>

[**] Development Programs [**]The Completed and Planned Clinical Studies
     Include:

     -    [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

[**] Cost: [**]
[**] . [**]

     -    Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

     -    [**]. [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    [**]Cost: 2.0 MM

     -    EOP1002 (COMPLETED): Phase I/II. [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

     -    [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]Logistics

          -    Initiation Date: Ongoing[**]Duration: [**] 3Q04 completion

     -    Estimated Cost: [**]. [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

          -    ESTIMATED COST: [**]

[**] [**]

     -    Objectives

     -    Primary: [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]

          -    DURATION: [**]

          -    ESTIMATED COST: [**]

                                       105

<PAGE>

     -    [**] [**]Objectives

     -    [**]Design:

     -    [**]NO-GO Criteria:

          -    [**].

     -    LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

     -    ESTIMATED COST: [**]. [**]Objectives:

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]ESTIMATED COST: [**]

[**].  [**]

     -    Objectives:

          -    [**].

     -    Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]

          -    DURATION: [**]

          -    ESTIMATED COST: [**]

          -

[**] [**]

     -    Objectives:

          -    Primary: [**]

     -    Design:

     -    [**]NO-GO Criteria:

          -    [**].

     -    LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

          -    ESTIMATED COST: [**]

     -    [**] [**]Objectives:

     -    [**]Design:

          -    [**]

     -    NO-GO Criteria:

     -    [**]LOGISTICS

                                       106

<PAGE>

          -    INITIATION DATE: [**]DURATION: [**]

[**] [**]

     -    Objectives

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**].

     -    ESTIMATED COST: [**]. [**]Objectives

     -    [**]Design:

     -    [**]NO-GO Criteria:

     -    [**]LOGISTICS

          -    INITIATION DATE: [**]DURATION: [**]

          -    ESTIMATED COST: [**]

                                       107

<PAGE>

                                 EXHIBIT 5.1(b)

                                      [**]

Note: all numbers in Millions of US dollars

<TABLE>
<CAPTION>
                      REMAINING
STUDY NUMBER/NAME    COSTS IN CDP    [**]
-----------------------------------------
<S>                  <C>             <C>
      [**]                           [**]
-----------------------------------------
      [**]                           [**]
-----------------------------------------
      [**]                           [**]
-----------------------------------------
      [**]                           [**]
-----------------------------------------
      [**]               [**]        [**]
-----------------------------------------
      [**]               [**]        [**]
-----------------------------------------
      [**]               [**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]

-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]        [**]
-----------------------------------------
      [**]              $[**]

-----------------------------------------
      [**]              $[**]
-----------------------------------------
      [**]              $[**]
-----------------------------------------
      [**]              $[**]
-----------------------------------------
</TABLE>

<TABLE>
<CAPTION>
                         [**]
                      REMAINING
STUDY NUMBER/NAME    COSTS IN CDP    [**]
-----------------------------------------
<S>                  <C>             <C>
-----------------------------------------
      [**]              $[**]        [**]

-----------------------------------------
      [**]              $[**]        [**]

-----------------------------------------
      [**]              $[**]
-----------------------------------------
      [**]              $[**]
-----------------------------------------
      [**]              $[**]
-----------------------------------------
      [**]              $[**]        [**]
                         [**]
-----------------------------------------
</TABLE>

                                       108

<PAGE>

<TABLE>
<S>                  <C>             <C>
-----------------------------------------
      [**]              $[**]
-----------------------------------------
</TABLE>

                                       109

<PAGE>

                                   EXHIBIT 6.2

                  Marketing Budgets and Detailing Requirements

     Marketing Budgets.  After Launch of the first AMD Product in the US
Territory, the following shall apply:

     Eyetech shall [**] set forth below. Pfizer shall [**]

<TABLE>
<S>     <C>     <C>     <C>     <C>
------------------------------------
[**]    [**]    [**]    [**]    [**]

------------------------------------
[**]    [**]    [**]    [**]
                                [**]
------------------------------------
</TABLE>

*Beginning with the [**] and thereafter [**] Marketing Expenses shall be
calculated as follows:

[**]

     Detailing Requirements.  The following principles shall apply to the
allocation of Detailing responsibilities between the Parties:

     (i)       [**] Eyetech shall [**] Detailing [**] of the Details [**] in
performing Details [**]

     (ii)      Pfizer shall [**] in performing Details [**]

     (iii)     Eyetech shall [**] detailing responsibilities.

     (iv)      [**] Eyetech shall [**] detailing responsibilities [**] under
this Agreement. [**]

     (v)       Detailing assignments shall be consistent with the principles
set forth in (i) to (iv) above, shall be set forth in each applicable Marketing
Plan [**]

<TABLE>
<S>     <C>     <C>     <C>     <C>
------------------------------------
        [**]    [**]    [**]    [**]

------------------------------------
[**]
------------------------------------
[**]    [**]    [**]    [**]    [**]
------------------------------------
[**]    [**]    [**]    [**]
------------------------------------
[**]
------------------------------------
[**]    [**]    [**]    [**]
------------------------------------
[**]    [**]    [**]    [**]
------------------------------------
</TABLE>

                                       110

<PAGE>

                                 EXHIBIT 6.12(a)

                     Pre-Existing Clinical Supply Agreements

1.   [**] Agreement dated [**] between Eyetech and [**]

2.   Purchase Order dated [**] between Eyetech and [**]

3.   Purchase Order dated [**] between Eyetech and [**]

4.   [**] between Eyetech and [**]

5.   [**] dated [**] between Eyetech and [**]

6.   Purchase Order dated [**] between Eyetech [**]

                                       111

<PAGE>

                                  EXHIBIT 10.4

                             Third Party Agreements

1.   Licensing Agreement dated as of March 30, 2000, by and among Eyetech,
     Gilead Sciences, Inc. and NeXstar Pharmaceuticals, Inc., as amended by
     Amendment No. 1 dated May 9, 2000 and as subsequently amended by Amendment
     No. 2 dated December 4, 2001 and as subsequently amended by Amendment No. 3
     dated August 30, 2002.

2.   License Agreement dated as of December 31, 2001, by and between Eyetech and
     Isis Pharmaceuticals, Inc.

3.   License, Manufacturing and Supply Agreement dated as of February 5, 2002,
     by and between Eyetech and Shearwater Corporation.

                                       112

<PAGE>

                              EXHIBIT 12.6(a)(iii)

                        Certain Product Liability Matters

Product Liability arising out of any claim by a patient enrolled as of the
Execution Date in an ongoing Eyetech clinical trial based on safety issues
related to Eyetech's pre-clinical testing program (other than reproductive
studies).

                                       113

<PAGE>

                             EXHIBIT 12.6(b)(iii)(A)

                       Eyetech 2002 Clinical Supply Costs

                            Direct Cost Estimate API
                                 Current (2002)

                                Clinical Product

API Yield per Run (grams) from                             [**]
    [**]mM Batch Size

<TABLE>
<CAPTION>
                                 $/Batch    $/gram
                                 -----------------
<S>                              <C>        <C>
Raw Material (critical)            [**]      [**]

Contract Cost [**]                $[**]     $[**]

Release Cost (QC/QA)              $[**]     $[**]

Total Direct Cost (API)           $[**]     $[**]
</TABLE>

Cost/gram = $[**]

Cost/mg = $[**]

Cost of [**]mg fill = ([**])*[**]*$[**] = $[**]
Note: [**]mg dose has a [**]% overfill

                                       114

<PAGE>

                             EXHIBIT 12.6(b)(iii)(B)

                    Certain Third Party Intellectual Property

                                      [**]

                                       115

<PAGE>

                                  EXHIBIT 17.15

                               Joint Press Release

For immediate release:                    Contacts: Justin Jackson
December 18, 2002                         212-213-0006
                                          (Burns McClellan on behalf of Eyetech)
                                          Geoffrey Cook
                                          212-733-5244 (Pfizer)

           PFIZER, EYETECH PHARMACEUTICALS ENTER GLOBAL COLLABORATION

                      FOR POTENTIAL TREATMENT FOR BLINDNESS

         New York, NY, December 18, 2002 - Pfizer Inc and Eyetech
Pharmaceuticals, Inc. today announced they have entered into an agreement to
jointly develop and commercialize Eyetech's Macugen(TM) (pegaptanib sodium), a
potential treatment for age-related macular degeneration (AMD) and diabetic
macular edema (DME), both leading causes of blindness.

         Under terms of the deal, which is subject to government approval,
Pfizer will make initial payments of $100 million, with the potential for an
additional $195 million in milestone payments based on worldwide regulatory
submission and approvals. Eyetech also has the potential to receive up to an
additional $450 million in milestone payments, which are contingent upon
successful commercialization of Macugen(TM) and based on attainment of
agreed-upon sales levels. Pfizer will also fund the majority of the ongoing
development costs for both the AMD and DME indications. Further, if approved,
Macugen(TM) will be co-promoted by Eyetech and Pfizer in the United States where
Eyetech will have an ophthalmology sales force and record sales. Outside of the
United States, Pfizer will market the product exclusively under a
royalty-bearing license. Additional payments are subject to worldwide
Macugen(TM) sales. Further terms of the deal were not disclosed.

         This is a landmark accomplishment for a young biotechnology company. We
are excited to partner with the world's leading pharmaceutical company to bring
a potentially innovative

                                       116

<PAGE>

therapy to so many patients who are at risk of losing their sight," said Dr.
David Guyer, Eyetech Pharmaceuticals' co-founder and chief executive officer.

         The U.S. Food and Drug Administration has granted Macugen(TM)
"fast-track" status for the treatment of exudative, or "wet" form of AMD as well
as for DME because of the product's expected potential to fulfill a significant
unmet medical need.

         "We are very pleased to partner with Eyetech on what we believe will be
a breakthrough treatment for a devastating medical condition," said Pfizer
President Karen Katen. "As the world's population ages, there will be an
increasing number of people at risk for macular degeneration."

         Administered by intravitreal injection, Macugen(TM) is an aptamer that
selectively binds to and neutralizes Vascular Endothelial Risk Factor (VEGF). In
early clinical studies, Macugen(TM) was shown to inhibit abnormal blood vessel
growth and stabilize and/or reverse blood vessel leakage in the back of the eye
resulting in improved vision by three lines or more on standard eye charts in 26
percent of patients.

         Eyetech's Phase III development program for wet AMD involves nearly
1,200 patients at 117 investigational sites in the United States, Canada, South
America, Europe, Israel and Australia, the largest clinical development program
of its kind. Macugen(TM) is being developed as monotherapy as well as in
combination with photodynamic therapy.

                   WET AGE-RELATED MACULAR DEGENERATION (AMD)

         The leading cause of irreversible vision loss among Americans over the
age of 55, AMD occurs in two different forms: dry AMD and wet AMD. The wet form
accounts for approximately 200,000 new cases annually, with a prevalence of 1.2
million cases in the United States alone.

         Wet AMD is characterized by the growth of abnormal blood vessels into
the area beneath the retina. This process, known as angiogenesis or
neovascularization, results in fragile blood vessels that leak fluid and blood
into the macula, the center portion of the retina. This leakage damages the area
and results in a rapid loss of central vision, which is critical for tasks such
as reading, driving, watching television and recognizing faces.

                                       117

<PAGE>

         Laser photocoagulation and photodynamic therapy are the only current
treatments for certain types of patients.

                          DIABETIC MACULAR EDEMA (DME)

         DME affects roughly 135,000 Americans with diabetes each year and is
the leading cause of blindness in adults under the age of 55. The decreased
vision that characterizes DME results from fluid and lipids leaking from retinal
blood vessels

         Eyetech Pharmaceuticals (www.eyetk.com) is dedicated to the discovery,
development and commercialization of novel therapeutics and delivery systems to
combat the vision loss associated with ophthalmic diseases. Founded in 2000, the
privately-held, New York City-based company is focused on meeting the medical
needs of patients with diseases that affect the back of the eye. Its investors
include partners and affiliates of JP

         Morgan, BB Biotech, MPM Capital, Alta Partners, Schroder Ventures, Life
Sciences and International BioTechnology Trust plc, and Merrill Lynch KECALP.
Pfizer Inc discovers, develops, manufactures and markets leading prescription
medicines, for humans and animals, and many of the world's best-known consumer
brands.

         DISCLOSURE NOTICE: The information contained in this document is as of
         December 18, 2002. Pfizer assumes no obligation to update any
         forward-looking statements contained in this document as a result of
         new information or future events or developments.

         This document contains forward-looking information about a product in
         development that involves inherent uncertainties. The success of this
         research and development project and the speed with which regulatory
         authorizations and the launch of the product may be achieved, as well
         as competitive factors, could affect the actual outcome of this
         collaboration.

         A further list and description of the risks, uncertainties and other
         matters that could cause the Pfizer's description contained herein to
         differ materially can be found in the Company's Annual Report on Form
         10-K for the fiscal year ended December 31, 2001, and in its periodic
         reports on Forms 10-Q and 8-K (if any).

                                       118

<PAGE>

                                EXHIBIT 17.15(c)

Permitted Disclosures[**]

                                       119<PAGE>

                                                                   EXHIBIT 10.53

          CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE
         SECURITIES AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

                                                                  EXECUTION COPY

                               LICENSING AGREEMENT

         This LICENSING AGREEMENT ("Agreement"), effective as of March 31, 2000
(the "Effective Date"), by and among GILEAD SCIENCES, INC., a Delaware
corporation with its principal office located at 333 Lakeside Drive, Foster
City, CA 94404 ("Gilead Sciences"), and its wholly-owned subsidiary, NEXSTAR
PHARMACEUTICALS, INC., a Delaware corporation (collectively with Gilead
Sciences, "Gilead"), and EYETECH PHARMACEUTICALS, INC., a Delaware corporation
with its principal offices located at 300 East 42nd Street, Third Floor, New
York, New York 10017 ("EyeTech"). Unless otherwise defined in this Agreement,
all capitalized terms shall have the meanings given to them in Section 1.1 of
this Agreement.

                                    RECITALS

         1.       WHEREAS, Gilead owns certain patents and patent applications
and related know-how for NX1838, and has made certain filings for regulatory
approvals with respect to NX1838; and

         2.       WHEREAS, Gilead and EyeTech desire to enter into this
Agreement and certain other agreements, including an agreement providing for the
fill-and-finish manufacture of quantities of Product sufficient for the
completion of Phase Ib clinical trials; and

         3.       WHEREAS, subject to the terms and conditions set forth in this
Agreement, Gilead wishes to license to EyeTech and EyeTech wishes to license
from Gilead all of Gilead's rights under patents, patent applications and
know-how related to NX1838, and have access to all regulatory approvals with
respect to NX1838; and

         4.       WHEREAS, subject to the terms and conditions set forth in this
Agreement, Gilead also wishes to sell to EyeTech and EyeTech wishes to purchase
from Gilead its inventory of NX1838.

         NOW, THEREFORE, the Parties hereto, intending to be legally bound,
hereby agree as follows:

                                    SECTION 1
                                   DEFINITIONS

         1.1      Definitions. For purposes of this Agreement, the following
terms shall have the meanings set forth below:

                                       1.
<PAGE>

         "Affiliate" shall mean any Person that, directly or indirectly, through
one or more intermediaries, Owns, is Owned by or is under common Ownership with,
a Party, where "Own" or "Ownership" means (a) direct or indirect possession of
at least fifty percent (50%) of the outstanding voting securities of a
corporation or a comparable ownership in any other type of Person, provided,
however, that if the law of the jurisdiction in which such entity operates does
not allow fifty percent (50%) or greater ownership by a Party, such ownership
interest shall be at least forty percent (40%) or (b) that a Person or group of
Persons otherwise has the unilateral ability to control and direct the
management of the entity, whether by contract or otherwise.

         "Business Day" shall mean any day other than a Saturday, Sunday or
banking holiday in New York City or San Francisco, California.

         "Calendar Quarter" shall mean a calendar quarter (i.e., period of three
(3) consecutive months) ending on March 31, June 30, September 30 or December
31.

         "Calendar Year" shall mean any period of twelve (12) consecutive months
ending on December 31.

         "Competitive Product" shall mean a product competitive with a Product.

         "Compulsory License" means a compulsory license under the Licensed
Patents obtained by a Third Party through the order, decree, or grant of a
governmental authority of competent jurisdiction, authorizing such Third Party
to manufacture, use, sell, offer for sale or import a Competitive Product in one
or more countries within the Territory.

         "Control", "Controls", and "Controlled" shall mean, with respect to a
particular item of information or intellectual property right, that the
applicable Party owns or has a license to such item or right and has the ability
to grant to the other Party access to and a license or sublicense (as
applicable) under such item or rights as provided for in this Agreement without
violating the terms of any agreement or other arrangement with any Third Party.

         "Damages" shall mean any and all costs, losses, claims, liabilities,
fines, penalties, damages and expenses, court costs, and reasonable fees and
disbursements of counsel, consultants and expert witnesses incurred by a Party
hereto (including any interest payments which may be imposed in connection
therewith).

         "Delivery Date" shall mean the date that is ten (10) days after the
Effective Date.

         "Effective Date" shall have the meaning given such term in the first
sentence of this Agreement.

         "EU" shall mean Austria, Belgium, Denmark, Finland, France, Germany,
Greece, Ireland, Italy, Luxembourg, The Netherlands, Portugal, Spain, Sweden and
the United Kingdom, and future members of the European Union (or its successor),
upon their admission for full membership (with commercial rights and privileges
substantially comparable to those of the foregoing countries).

                                       2.
<PAGE>

         "EyeTech Rights" shall mean any invention or inventions, patentable or
not, know-how, information and/or data relating to the Product, including,
without limitation, pre-clinical studies and clinical trial information,
manufacturing processes, formulations, modes of delivery and/or data necessary
for the manufacture, use or sale of the Product, which are Controlled by EyeTech
during the term of this Agreement, and all Patents covering any of the foregoing
which are Controlled by EyeTech during the term of this Agreement.

         "FDA" shall mean the United States Food and Drug Administration, or any
successor thereto.

         "Field" shall mean the prevention and treatment of all human and other
animal diseases and conditions, and expressly excluding in vivo and in vitro
diagnostic applications.

         "First Commercial Sale" shall mean, with respect to any particular
country, the first sale of a Product in such country by EyeTech, or any of its
Affiliates or sublicensees, after Regulatory Approvals in such country have been
granted from the relevant Regulatory Authority in such country for such Product.

         "GAAP" shall mean United States generally accepted accounting
principles, consistently applied.

         "Indemnified Party" shall have the meaning given in Section 7.2 hereof.

         "Indemnifying Party" shall have the meaning given in Section 7.2
hereof.

         "Know-How" shall mean all ideas, materials, inventions (whether
patentable or not), trade secrets, data, instructions, processes, formulas,
expert opinion and information, including, without limitation, the Manufacturing
Information and biological, chemical, pharmacological, toxicological, physical
and analytical, safety, manufacturing and quality control data and information,
in each case within the Field, that, as of the Effective Date are (i) existing,
and (ii) Controlled by Gilead as of the Effective Date, in each case which is
necessary or useful for the development, manufacture, use, sale or
commercialization of the Product in the Field. Excluded from Know-How are any
Patents, the Licensed Patents and the Transferred Assets.

         "License" shall mean the license granted by Gilead to EyeTech pursuant
to Section 2.1.

         "Licensed Patents" shall mean any Patents listed in Exhibit D (as
updated from time to time pursuant to Section 5.6) which claim the manufacture,
use, import, offer for sale or sale of Products in accordance with this
Agreement and which now or at any time during the term of this Agreement are
Controlled by Gilead or any Affiliate of Gilead.

         "Major Countries" shall mean Canada, France, Germany, Italy, Japan,
Spain, United Kingdom and the United States.

         "Manufacturing Information" shall mean copies of all existing
information in written and electronic form in Gilead's possession or control as
of the Effective Date, with respect to any Product existing as of the Effective
Date, that relates to, in the Field: (1) processes for the production of NX1838,
and intermediates in the preparation of a Product; (2) the in-process

                                       3.
<PAGE>

analytical controls for production of each of: (a) NX1838; and (b) a Product;
(3) the process, formulation and development reports generated for the
preparation of a Product; (4) the analytical methods and validation for the
quality control release of each of: (a) NX1838; and (b) a Product; and (5) the
stability protocols, stability indicating methods and stability data for each
of: (a) NX1838; and (b) a Product.

         "NDA" shall mean a New Drug Application filed with the FDA requesting
market approval for a new drug product.

         "Net Sales" shall mean, with respect to the Product, the gross amount
billed or invoiced by EyeTech, its Affiliates or sublicensees, to unrelated
Third Parties for the Products in finished product form, less the following
deductions:

                  (a)      trade, quantity and cash discounts allowed, but
expressly excluding discounts or allowances offered as part of a package of
products that includes a Product sold by EyeTech, its Affiliates or
sublicensees;

                  (b)      refunds, chargebacks and any other allowances which
effectively reduce the net selling price;

                  (c)      actual product returns, credits and allowances;

                  (d)      rebates actually paid or credited to any governmental
agency (or branch thereof) or to any Third Party payor, administrator or
contractee;

                  (e)      discounts mandated by, or granted to meet the
requirements of, applicable state, provincial or federal law, wholesaler,
including required chargebacks and retroactive price reductions;

                  (f)      transportation, freight, postage charges and other
charges such as insurance, relating thereto, in each case included as a specific
line item on an invoice to such Third Parties; and

                  (g)      taxes, excises or other governmental charges upon or
measured by the production, sale, transportation, delivery or use of goods, in
each case included as a specific line item on an invoice to such Third Parties.

Notwithstanding the foregoing, amounts received by EyeTech, or its Affiliates or
sublicensees, for the sale of Products among EyeTech and its Affiliates or
sublicensees for resale shall not be included in the computation of Net Sales
hereunder. Net Sales shall be determined from books and records maintained in
accordance with GAAP. In the event the Product is sold as part of a combination
product, or as part of bundled products or as part of a delivery system, the Net
Sales from the combination product, bundled product or delivery system, for the
purposes of determining royalty payments, shall be determined by multiplying the
Net Sales (as defined without regard to this paragraph) of the combination
product by the fraction, A/(A+B) where A is the average sale price of the
Product when sold separately in finished form and B is the average sale price of
the other product(s) or system sold separately in finished form, or, only if the
value of B cannot be determined, where A+B is the average sales price of the
product(s) and

                                       4.
<PAGE>

the delivery system together. If the value of B can be determined, in no event
will the sales price of any combination product, bundled product or delivery
system product be less than the sum of A and B. In the event that such average
sale price cannot be determined for both the Product and such other product(s)
or system in combination, the following calculation shall be substituted for the
calculation recited in (ii) of the preceding sentence: the Net Sales (as defined
without regard to this paragraph) of the combination products shall be
multiplied by the fraction C/(C+D) where C is EyeTech's cost of goods of the
Product and D is EyeTech's cost of goods for the other product(s) or system,
determined in accordance with the method of accounting normally employed by
EyeTech in computing cost of goods, provided, however, that the minimum value of
such fraction as used in the calculation of Net Sales shall be 0.9.

         "NX1838" shall mean Gilead's proprietary compound known as NX1838, as
described in Exhibit A.

         "Party" shall mean either Gilead or EyeTech, and "Parties" shall mean
both of Gilead and EyeTech.

         "Patents" shall mean patents and patent applications, both foreign and
domestic, including without limitation, all extensions, reissues, renewals,
reexaminations, patents of addition, supplementary protection certificates and
inventors' certificates thereof, substitutions, provisionals, divisionals,
continuations and continuations-in-part.

         "Person" shall mean a natural person, a corporation, a partnership, a
trust, a joint venture, a limited liability company, any governmental authority
or any other entity or organization.

         "Pivotal Clinical Trial" shall mean either (a) a trial on sufficient
numbers of patients that is designed to establish that a pharmaceutical product
is safe and efficacious for its intended use, and to define warnings,
precautions and adverse reactions that are associated with the pharmaceutical
product in the dosage range to be prescribed, and to support Regulatory Approval
of such pharmaceutical product or label expansion of such pharmaceutical
product, or (b) a clinical trial that began as a trial on sufficient numbers of
patients that is designed to establish the safety and biological activity of a
pharmaceutical product for its intended use, and to define warnings, precautions
and adverse reactions that are associated with the pharmaceutical product in the
dosage range to be prescribed, after such date as the U.S. Food and Drug
Administration or its successor (or equivalent regulatory authority) has
indicated that the applicable Party may reasonably continue such trials with the
intention to establish that a pharmaceutical product is safe and efficacious for
its intended use, and to define warnings, precautions and adverse reactions that
are associated with the pharmaceutical product in the dosage range to be
prescribed, and to support Regulatory Approval of such pharmaceutical product or
label expansion of such pharmaceutical product.

         "Product" shall mean any pharmaceutical composition containing NX1838
in any formulation, dosage concentration or volume, together with all label
expansions, line extensions and improvements thereon, which may be included in
any supplement, modification or addition to the filings for Regulatory Approval
of the foregoing compound.

                                       5.
<PAGE>

         "Product Data Package" shall include the following information and data
related to the Product in the possession or control of Gilead as of the
Effective Date: (a) the Regulatory Documents; (b) pre-clinical and clinical
development protocols, data, and reports; (c) manufacturing development
technical reports; (d) toxicology reports; and (e) such other information and
data specifically identified in Exhibit B attached hereto.

         "Product Inventory" shall mean the NX1838 and Product inventory, in
bulk or finished form, which Gilead Controls as of the Effective Date, as
identified in Exhibit C attached hereto.

         "Reasonable Diligence" shall mean commercially reasonable efforts to
develop, obtain Regulatory Approval, and/or commercialize, as applicable, a
Product in a country in the Territory, consistent with accepted business
practices and legal requirements, and comparable to efforts in the
pharmaceutical industry applicable to development, obtaining of Regulatory
Approval for, or commercialization of human pharmaceutical products at an
equivalent stage of development and similar market potential, profit potential
and strategic value in view of conditions then prevailing.

         "Regulatory Approval" shall mean (a) in the United States, approval by
the FDA of an NDA, or equivalent application, for marketing approval and
satisfaction of any related applicable FDA registration and notification
requirements (if any) and (b) in any country other than the United States, all
approvals (including any required marketing, pricing and reimbursement
approvals) by the Regulatory Authority in such country of a single application
or set of applications comparable to an NDA, enabling legal sale of a product in
such country.

         "Regulatory Authority" shall mean the FDA in the United States or the
equivalent governmental agency having jurisdiction in any other country in the
Territory.

         "Regulatory Documents" shall mean the (a) United States investigational
new drug application (the "IND") #56503 (dated July 12, 1998), and all
amendments and annual reports to same; (b) any pediatric data package or other
exclusivity extensions relating to Products; and (c) any other regulatory
filings with Regulatory Authorities relating to the Product.

         "Royalty Term" shall mean, with respect to each country in which
Product is sold, the period of time equal to the longer of (i) ten (10) years
from the date of First Commercial Sale of the Product in such country, or (ii)
the expiration of the last-to-expire Licensed Patent in such country that claims
the manufacture, use, and or sale of such Product as such activities are carried
out pursuant to this Agreement.

         "Territory" shall mean the world, unless the License terminates with
respect to a country pursuant to Section 6.7, in which case the Territory shall
exclude any country in which the License has so terminated.

         "Third Party" shall mean a Person other than EyeTech, Gilead or their
Affiliates.

         "Transferred Assets" shall mean the Product Inventory and the Product
Data Package.

                                       6.
<PAGE>

                                    SECTION 2
           GRANT OF LICENSES AND TRANSFER AND DELIVERY OF TRANSFERRED
                      ASSETS AND MANUFACTURING INFORMATION

         2.1      Grant of License. Subject to the terms and conditions of this
Agreement, during the term of this Agreement, Gilead hereby grants to EyeTech an
exclusive license under the Licensed Patents and Know How to make, have made,
use, sell, offer to sell, import and export the Product within the Field
throughout the Territory, with a right to sublicense to its Affiliates or
(subject to Section 2.4) to any other Person.

         2.2      Transferred Assets. As of the Effective Date, Gilead hereby
assigns, transfers and conveys to EyeTech all of Gilead's right, title and
interest in and to the Transferred Assets (subject to Section 4.5(c)), and
EyeTech hereby accepts such assignment, transfer and conveyance. On or before
the Delivery Date, Gilead shall have delivered to EyeTech all of the Transferred
Assets and the Manufacturing Information. EyeTech shall have up to ten (10) days
after such delivery to inventory the delivered Transferred Assets and
Manufacturing Information and to give notice to Gilead of any Transferred Assets
and Manufacturing Information that were not so delivered. If Gilead receives
notice or otherwise learns after the Delivery Date that it has failed to deliver
any Transferred Assets or Manufacturing Information to EyeTech, Gilead shall
provide to EyeTech any such Transferred Assets or Manufacturing Information no
later than five (5) Business Days after receipt of such notice or knowledge (or
within such longer time as is mutually agreed by EyeTech and Gilead). The
clinical data portion of the Product Data Package shall be provided to EyeTech
in computer-readable format, where available, and otherwise in printed format.
Gilead shall be under no obligation to convert to electronic format any portion
of the Product Data Package that currently is available only in printed format.
In the event that EyeTech is unwilling or unable to assume physical possession
of the Transferred Assets and Manufacturing Information by the Effective Date,
Gilead shall be entitled to charge EyeTech a reasonable fee for storage of the
Transferred Assets and Manufacturing Information beyond the Effective Date.
Gilead shall ship the Transferred Assets to EyeTech F.O.B. to EyeTech's
designated facilities. For a period of 90 days following the receipt by EyeTech
of the Transferred Assets and Manufacturing Information, Gilead personnel shall
be reasonably available during Gilead's normal business hours to respond to
technical inquiries of EyeTech regarding Products as is reasonably requested by
EyeTech. EyeTech acknowledges that Gilead makes no representations or warranties
with respect to the Transferred Assets or Manufacturing Information (other than
as expressly set forth in Section 5 below) and that it accepts such Transferred
Assets and Manufacturing Information "as is."

         2.3      Negative Covenant of EyeTech. EyeTech shall not use or
practice Licensed Patents or Know-How outside the Field or outside the Territory
or for any other purpose except activities that it conducts in compliance with
this Agreement.

         2.4      Sublicenses. EyeTech shall have the right to sublicense the
licenses granted to it by Gilead under this Agreement without the consent of
Gilead; provided that (i) prompt notice and a copy of such sublicense shall be
given by EyeTech to Gilead pursuant to Section 8.2 of this Agreement; (ii)
EyeTech shall remain obligated at all times under this Agreement without regard
to whether it has sublicensed its rights or whether EyeTech's sublicensee has
performed; (iii)

                                       7.
<PAGE>

such sublicense shall name Gilead as a third party beneficiary of such
sublicense; and (iv) any such sublicenses granted by EyeTech shall contain
provisions providing for its termination or assignment to Gilead, at the option
of Gilead, of EyeTech's interest therein upon termination of this Agreement, and
shall further contain provisions which obligate such sublicensee to comply with
such terms, conditions, agreements and obligations that are consistent with the
terms, conditions, agreements and obligations to which EyeTech is subject under
this Agreement.

         2.5      Gilead Right of First Negotiation. Except as otherwise
provided in this Section 2.5, Gilead shall have a right of first negotiation
with respect obtaining all rights with respect to any Product which is, or which
can reasonably be expected to be, [**] (a "Reversion Product") as follows:
Eyetech shall notify Gilead in writing if Eyetech intends to seek, negotiate, or
solicit offers to license a Third Party to commercialize the Reversion Product
for the treatment or prevention [**] (the "Reversion Field") and a specific
territory (the "Reversion Territory"), prior to contacting any such potential
Third Party licensees. Such written notice shall include sufficient detailed
technical information concerning the Reversion Product as Gilead may reasonably
require to evaluate its interest in such Reversion Product. Within thirty (30)
days after receiving Eyetech's notice as to the Reversion Product, Gilead shall
notify Eyetech whether it is interested in negotiating with Eyetech the terms
under which Gilead shall obtain a license from Eyetech to research, develop and
commercialize Reversion Products as described herein. If Gilead provides such
notice, the Parties shall negotiate exclusively and in good faith for a period
of up to ninety (90) days after Eyetech receives Gilead's notice of interest
(the "Negotiation Period") the terms of an agreement pursuant to which Eyetech
will grant to Gilead and its Affiliates an exclusive, royalty-bearing,
sublicensable license, under all Eyetech Know-How and Eyetech Patents relating
to such Reversion Product, to research, develop, make, have made, use, import,
offer for sale, sell and otherwise commercialize such Reversion Product within
the Reversion Field within the Reversion Territory, and which agreement shall
include commercially reasonable provisions for transfer of or access to relevant
regulatory filings and technology to Gilead. Neither Gilead nor Eyetech shall
have any obligation to actually enter into a license agreement with respect to
such Reversion Product. If either Gilead does not respond to Eyetech's notice of
intent to license the Reversion Product within thirty (30) days after Gilead's
receipt thereof, or Gilead and Eyetech fail to agree upon the terms of a license
under rights to the Reversion Product during the Negotiation Period, Eyetech
shall be free to commercialize such Reversion Product by itself or through its
Affiliates or Third Parties without further obligation to Gilead.

                                    SECTION 3
                             PAYMENTS AND DELIVERIES

         In consideration of the exclusive license granted herein and the
transfer of ownership of the Transferred Assets, EyeTech shall pay the following
amounts to Gilead:

         3.1      Initial Payments and Deliveries.

                  (a)      On Monday, April 3, 2000, EyeTech shall pay to Gilead
the sum of seven million United States Dollars (US$7,000,000) by Federal Reserve
electronic wire transfer in immediately available funds to an account designated
by Gilead. Such amount shall be non-refundable and non-creditable, and shall not
be subject to any counterclaim or set-off.

                                       8.
<PAGE>

                  (b)      On or before the Effective Date, EyeTech and Gilead
Sciences shall enter into a Warrant Agreement (the "Warrant Agreement") mutually
satisfactory to both Parties pursuant to which EyeTech shall issue to Gilead
Sciences a warrant to purchase EyeTech Series B Preferred Stock.

                  (c)      On or before the Delivery Date, Gilead shall deliver
to EyeTech (i) all of the Transferred Assets pursuant to Section 2.2 of this
Agreement; (ii) all of the Manufacturing Information pursuant to Section 2.2 of
this Agreement; and (iii) a schedule ("Schedule of Transferred Assets and
Manufacturing Information") setting forth each of the Transferred Assets and
Manufacturing Information being delivered to EyeTech at such time.

                  (d)      Within ten (10) days of delivery of the Transferred
Assets and the Manufacturing Information and of the Schedule of Transferred
Assets and Manufacturing Information pursuant to Section 3.1(c) above, EyeTech
shall inventory the delivered Transferred Assets and Manufacturing Information
pursuant to Section 2.2 and shall either (i) deliver to Gilead a receipt
acknowledging the receipt of each of the Transferred Assets and the
Manufacturing Information set forth on the Schedule of Transferred Assets and
Manufacturing Information or (ii) notify Gilead of any Transferred Assets or
Manufacturing Information that Gilead did not deliver. If Gilead receives notice
or otherwise learns after the Delivery Date that it has failed to deliver any
Transferred Assets or Manufacturing Information to EyeTech, Gilead shall provide
to EyeTech any such Transferred Assets or Manufacturing Information no later
than five (5) Business Days after receipt of such notice or knowledge (or within
such longer time as is mutually agreed by EyeTech and Gilead). Within ten (10)
days of Gilead delivering such missing items to EyeTech following notice given
by EyeTech pursuant to clause (ii) of this Section 3.1(d), EyeTech shall deliver
the receipt described in clause (i) of this Section 3.1(d).

         3.2      Milestone Payments. Within five (5) Business Days of EyeTech
and/or its Affiliates or sublicensees achieving the first occurrence of each of
the milestone events listed below with respect to any Product, EyeTech shall
notify Gilead of such achievement and the date thereof, and within thirty (30)
days of the date of such achievement, pay the one-time non-refundable fees
specified below to Gilead by Federal Reserve electronic wire transfer in
immediately available funds to an account designated by Gilead; provided,
however, that in no event shall the following fees be payable more than once
with respect to Products for any particular geographical area or Milestone:

<TABLE>
<CAPTION>
            Milestone                                                      Fee
------------------------------------                                      -----
<S>                                                                       <C>
First [**] with respect to a Product                                      $[**]

First [**] with respect to a Product                                      $[**]

First [**] with respect to a Product                                      $[**]

First [**] with respect to a Product                                      $[**]

First [**] with respect to a Product                                      $[**]

First [**] with respect to a Product                                      $[**]
</TABLE>

                                       9.
<PAGE>

         3.3      Royalties.

                  (a)      Royalty on Products. EyeTech shall pay Gilead a
royalty payment on Net Sales of Products that are made or sold during the
Royalty Term and that are sold by EyeTech, its Affiliates or sublicensees (the
"Royalty") according to the following rates, as adjusted in accordance with
Sections 3.3(b) below:

                           (i)      [**] percent ([**]%) of Net Sales in the
United States for the first [**] million dollars ($[**]) in Net Sales in the
United States in a given Calendar Year;

                           (ii)     [**] percent ([**]%) of Net Sales in the
United States for the next [**] dollars ($[**]), up to and including, [**]
dollars ($[**]) in Net Sales during the same Calendar Year;

                           (iii)    [**] percent ([**]%) of Net Sales in the
United States in excess of [**] dollars ($[**]) during the same Calendar Year;
and

                           (iv)     [**] percent [**]%) of Net Sales outside the
United States in the same Calendar Year.

         By way of example, if, in the year 2005, EyeTech Net Sales in the
United States were equal to [**] dollars ($[**]), and [**] dollars ($[**])
outside the United States, then the Royalty payable to Gilead hereunder would
equal [**] dollars ($[**]), calculated in the following manner:

<TABLE>
<CAPTION>
AMOUNT OF NET SALES                               ROYALTY RATE           ROYALTY
----------------------------                      ------------           -------
<S>                                               <C>                    <C>
First $[**] (United States)                           [**]%               $ [**]
Next $[**] (United States)                            [**]%               $ [**]
Next $[**] (United States)                            [**]%               $ [**]
$[**] (outside United States)                         [**]%               $ [**]
----------------------------                                              ------
       Total Royalty                                                      $ [**]
</TABLE>

         By way of further example, if, through the second Calendar Quarter in
the year 2005, EyeTech Net Sales in the United States were equal to [**] dollars
($[**]), and [**] dollars ($[**]) outside the United States, then the Royalty
payable to Gilead hereunder after such Calendar Quarter would equal [**] dollars
($[**]), calculated in the following manner:

<TABLE>
<CAPTION>
AMOUNT OF NET SALES                               ROYALTY RATE           ROYALTY
                                                  ------------           -------
<S>                                               <C>                    <C>
First $[**] (United States)                           [**]%               $ [**]
Next $[**] (United States)                            [**]%               $ [**]
$[**] (outside United States)                         [**]%               $ [**]
----------------------------                                              ------
       Total Royalty                                                      $ [**]
</TABLE>

                                      10.
<PAGE>

                  (b)      Offset. Notwithstanding the forgoing, on a country by
country and Product by Product basis, EyeTech may credit against Net Sales [**]
percent ([**]%) of any royalties it must pay to any Third Party on any Product:
(1) pursuant to any licenses necessary to practice the License; or (2) resulting
from any litigation (including settlement thereof) under Section 6.16; provided,
however, for purposes of this Section 3.3(b) that the applicable royalty rates
used for calculation of Royalties payable to Gilead shall not be reduced to less
than [**] percent ([**]%) of the royalty rates(s) otherwise applicable pursuant
to Section 3.3(a).

         3.4      Payment; Report. All Royalties payable to Gilead under this
Agreement shall be paid in U.S. dollars within sixty (60) days of the end of
each Calendar Quarter or as otherwise specifically provided herein by Federal
Reserve electronic wire transfer in immediately available funds to an account
designated by Gilead. At the time of payment of Royalties, EyeTech shall send to
Gilead a statement with respect to the applicable Calendar Quarter, country by
country and Product by Product, for EyeTech, its Affiliates and sublicensees, of
the amount of aggregate worldwide gross sales and Net Sales, the amount of gross
sales during such Calendar Quarter, an itemized calculation of Net Sales showing
deductions provided for in the definition of Net Sales and in Section 3.3(b),
and, on a cumulative basis for the current Calendar Year, the amount of
Royalties or other payments due on such sales.

         3.5      Exchange Rate; Manner and Place of Payment.

                  (a)      All payments due hereunder from time to time shall be
paid in U.S. Dollars. For purposes of computing such payments, the Net Sales of
Product in countries other than the United States shall be converted into U.S.
Dollars as computed using the average monthly rate of exchange at the time for
such currencies as the rate applicable to the transfer of funds arising from
payments as published in the Wall Street Journal (New York edition). The
currency conversion system used by EyeTech shall be subject to audit by Gilead
as described in Section 3.6 and, if not determined to be a system reflecting the
fair market value of the currencies in question, shall be modified as necessary
to effect currency conversion at fair market value.

                  (b)      Notwithstanding the provisions of Section 3.5(a), if
by reason of any restrictive exchange laws or regulations, EyeTech shall be
unable to convert to U.S. Dollars the amount, determined as above, equivalent to
the amount due by EyeTech hereunder, then EyeTech shall so notify Gilead
promptly and provide an explanation of the circumstances. In such event, EyeTech
shall make all such payments or the balance thereof due hereunder and which is
not paid in foreign currency as provided below, in U.S. Dollars as soon as
reasonably possible after and to the extent that such restrictive exchange laws
or regulations are lifted so as to permit EyeTech to pay amounts due under this
Section 3.5 in U.S. Dollars. EyeTech shall promptly notify Gilead if such
restrictions are so lifted. At its option Gilead shall meanwhile have the right
to request the payment (to it or to its nominee), and, upon request, EyeTech
shall pay or cause to be paid amounts due (or such portions thereof as are
specified by Gilead) in the currency of any other country designated by Gilead
and legally available to EyeTech under the then-existing laws of regulations.
Any payments shall be payable to Gilead by wire transfer at such bank in the
United States as Gilead Sciences shall specify from time to time. Not less than
one (1) Business Day prior to such wire transfer, the remitting party shall
telefax the receiving party advising it of the amount and of the payment to be
made.

                                      11.
<PAGE>

         3.6      Audits. EyeTech and its Affiliates and sublicensees shall keep
full and accurate books and records relating to the financial performance of the
Product. During the term of this Agreement plus four (4) years after termination
or expiration of this Agreement, Gilead shall have the right, during regular
business hours and upon reasonable advance notice, to have such books and
records audited by an independent certified accountant so as to verify the
accuracy of the information previously reported to Gilead. Such information
shall be deemed to be Proprietary Information of EyeTech and, as such, subject
to confidentiality obligations pursuant to Section 6.3. The independent
certified account shall keep confidential any Proprietary Information obtained
during such audit and shall report to Gilead only the amounts of Royalties due
and payable. The cost of such audit shall be borne by Gilead; however, in the
event such audit reveals that the Royalties to Gilead constitute an underpayment
of five percent (5%) or more from that revealed by the audit to be actually
owed, the cost of the audit shall be borne by EyeTech. EyeTech shall include in
all sublicenses granted as permitted under Section 2.4 an audit provision
substantially similar to the foregoing requiring the sublicensee to keep full
and accurate books and records relating to the Product and granting Gilead the
right to audit the accuracy of the information reported by the sublicensee in
connection therewith on the same terms as apply to an audit of EyeTech's records
hereunder. The terms of this Section 3.6 shall survive any termination or
expiration or termination of this Agreement for a period of four (4) years.

         3.7      Withholding Taxes. Any and all taxes levied on account of
royalty payments paid or owed from a country in which provision is made in the
law or by regulation for withholding will be deducted from royalty payments paid
Gilead hereunder. EyeTech shall cooperate with Gilead to claim exemption from
such deductions or withholdings under any double taxation or similar agreement
in force from time to time.

         3.8      Sublicensee Obligations. In the event EyeTech sublicenses its
right to sell a Product, such sublicense shall include an obligation for the
sublicensee to account for and report its Net Sales of Products and provide that
Gilead shall have audit rights therefor pursuant to this Section 3 on the same
basis as if such sales were Net Sales of Products by EyeTech, and EyeTech shall
pay royalty payments to Gilead as if the Net Sales of the sublicensee were Net
Sales of EyeTech.

         3.9      Late Payments. Any amounts not paid by EyeTech when due under
this Agreement shall be subject to interest from and including the date payment
is due through and including the date upon which Gilead has collected
immediately available funds in an account designated by Gilead at a rate equal
to the sum of two percent (2%) plus the prime rate of interest quoted in the
Money Rates section of The Wall Street Journal, calculated daily on the basis of
a 360-day year, or similar reputable data source. No special notice by Gilead to
EyeTech of such interest due shall be required.

         3.10     Compulsory License. If either Party learns that a Third Party
has obtained a Compulsory License in any country in the Territory, such Party
shall promptly notify the other Party of such occurrence. If the royalty rate
payable by the grantee of the Compulsory License is less than the royalty rates
applicable in such country set forth in Section 3.3 of this Agreement, then the
applicable royalty rates set forth in Section 3.3 of this Agreement shall be
reduced to the lower royalty rates applicable in such country pursuant to such
Compulsory License for so long

                                      12.
<PAGE>

as sales of a Competitive Product are made by any Third Party pursuant to the
Compulsory License.

                                    SECTION 4
                         TERM OF AGREEMENT; TERMINATION

         4.1      Term. The term of this Agreement shall commence upon the
Effective Date and, unless sooner terminated as provided in this Section 4,
expire on the expiration of all Royalty Terms for all Products.

         4.2      Licenses upon Expiration. In the event that the Agreement
expires as set forth in Section 4.1 above without early termination, the License
shall automatically become, at EyeTech's election made at least 90 days prior to
such expiration, either (i) an exclusive, irrevocable, royalty-bearing license,
subject to the surviving provisions of the Agreement, to use and/or sublicense
the use of Know How to make, have made, use, import, have imported, offer for
sale, sell, and have sold Product(s) in the Field in the Territory as it exists
at the time of such expiration, subject to payment by EyeTech to Gilead of a
royalty equal to [**] percent ([**]%) of Net Sales of Products made pursuant to
the license under this Section 4.2(i) after the expiration of this Agreement, or
(ii) a non-exclusive, irrevocable, royalty-free, paid-up license, subject to the
surviving provisions of this Agreement, to use and/or sublicense the use of Know
How to make, have made, use, import, have imported, offer for sale, sell, and
have sold Product(s) in the Field in the Territory as it exists at the time of
such expiration.

         4.3      Termination for Breach. Each Party shall have the right to
terminate this Agreement and its obligations hereunder for material breach by
the other Party, which breach remains uncured for sixty (60) days after written
notice is provided to the breaching Party, or in the case of an obligation to
pay royalty payments or other amounts owing under this Agreement, which breach
remains uncured for thirty (30) days after written notice to the breaching
Party; provided, however, that non-payment of any royalty amounts or other
payments owing under this Agreement, for which the non-paying Party reasonably
disputes the obligation or amounts not paid, shall not be deemed a breach of an
obligation to pay royalty payments or other amounts owing under this Agreement,
provided that the non-paying Party has paid all such amounts not in reasonable
dispute.

         4.4      Termination in Event of Patent Challenge. Gilead shall have
the right to terminate this Agreement if EyeTech challenges the validity of the
Licensed Patents within any country in the Territory, effective thirty (30) days
after EyeTech's receipt of written notice of such termination by Gilead.

         4.5      Reversion of Product Rights.

                  (a)      Termination of Agreement. In the event that this
Agreement is terminated pursuant to Sections 4.3 or 4.4 above, other than for
Gilead's material breach of this Agreement, the License shall terminate
immediately upon such termination.

                  (b)      Loss of License Rights in Country. In the event that
EyeTech permanently loses its right to use and sell Products in any country
other than by reason of any

                                      13.
<PAGE>

action or failure to act on the part of Gilead or any party acting on behalf of
Gilead, the License shall terminate with respect to such country.

                  (c)      Transfer of Rights. With respect to any and all
countries in which EyeTech's license rights are terminated pursuant to Sections
4.5(a), 4.5(b), or 6.7(b): (i) such country(ies) shall automatically be removed
from the Territory; (ii) EyeTech hereby grants to Gilead an exclusive, freely
sublicensable license under the EyeTech Rights, which license shall be
royalty-free and paid-up, subject to Section 4.5(d), to make, have made, use,
import, offer for sale, sell and otherwise research, develop and commercialize
formulations of the NX1838 in such countries, and Gilead covenants not to
practice such license until the actual termination of EyeTech's license rights
as to such countries pursuant to Sections 4.5(a) or (b); (iii) EyeTech shall
assign all of its right, title and interest in and to, and shall cooperate in
the transfer of all of, the following related to Products to the extent that
EyeTech Controlled such during the term of this Agreement: (A) INDs and
Regulatory Approvals, (B) all pre-clinical and clinical development protocols,
data, and reports and other information and data (with any clinical data to be
in computer-readable format, where available, and otherwise in printed format,
with no obligation of EyeTech to convert to electronic format any portion of
such clinical data that currently is available only in printed format), (C)
manufacturing development technical reports, (D) toxicology reports, and (E)
such other information and data specifically identified in Exhibit B or of such
type (the preceding (A), (B), (C), (D) and (E) constituting the "Updated Product
Data Package"), (iv) EyeTech shall deliver to Gilead copies of all information,
records and data that it Controls that are reasonably necessary for the
research, development and commercialization of Products, including without
limitation all clinical data relating to Products, forward to Gilead samples of
all chemical and biological materials acquired, made, cloned, synthesized, first
discovered or collected as a result of research development or commercialization
of Products and reasonable necessary to continue the research, development and
commercialization of Products, and take such other actions and execute such
other instruments, assignments and documents as may be necessary to effect the
transfer of rights and materials hereunder to Gilead; and (v) EyeTech shall
provide assistance reasonably requested by Gilead for a period of ninety (90)
days following the date of notice of termination to facilitate the exercise of
the license granted to Gilead in Section 4.5(c)(ii).

                  (d)      Royalties. Any license granted to Gilead pursuant to
Section 4.5(c) shall be subject to payment of a royalty to EyeTech on a
country-by-country basis at a rate equal to: (i) if such license is granted
after initiation of Pivotal Clinical Trials for a Product applicable to such
country, [**] percent ([**]%) of Gilead's net sales of Products in such country,
or (ii) if such license is granted on or after the first Regulatory Approval of
Product in such country, [**] percent ([**]%) of Gilead's net sales of Products
in such country.

         4.6      Accrued Rights and Obligations; Survival. Termination or
expiration of this Agreement for any reason shall be without prejudice to any
rights which shall have accrued to the benefit of either Party prior to such
termination or expiration, including damages arising from any breach hereunder.
The following provisions of this Agreement shall survive the expiration or
termination of this Agreement: Sections 2.3, 4.2, 4.6, 5, 6.3, 6.4, 6.5, 6.9,
6.11(a), 6.12, 6.18, 7, 8. The following provisions of this Agreement shall
survive the expiration of this Agreement to the extent that the license granted
to EyeTech pursuant to Section 4.2 is in effect: Sections 3.4 through 3.9, 4.3,
4.5, 6.2, 6.7(d), 6.7(f), 6.8, 6.11(b), 6.11(c), 6.11(d), 6.13, 6.16 and
6.17(a).

                                      14.
<PAGE>

                                    SECTION 5
                         REPRESENTATIONS AND WARRANTIES

         5.1      Corporate Existence and Power. As of the Effective Date, each
Party represents and warrants to the other that it (a) is a corporation duly
organized, validly existing and in good standing under the laws of the state in
which it is incorporated, and (b) has full corporate power and authority and the
legal right to own and operate its property and assets and to carry on its
business as it is now being conducted and as contemplated in this Agreement,
including, without limitation, the right to grant the licenses granted
hereunder.

         5.2      Authority and Binding Agreement. As of the Effective Date,
each Party represents and warrants to the other that it (a) has the corporate
power and authority and the legal right to enter into this Agreement and perform
its obligations hereunder, (b) has taken all necessary corporate action on its
part required to authorize the execution and delivery of the Agreement and the
performance of its obligations hereunder, and (c) the Agreement has been duly
executed and delivered on behalf of such Party, and constitutes a legal, valid
and binding obligation of such Party and is enforceable against it in accordance
with its terms.

         5.3      Title. As of the Effective Date, each Party represents and
warrants to the other that it has sufficient legal and/or beneficial title under
its intellectual property rights necessary to perform activities contemplated
under this Agreement and to grant the licenses contained in this Agreement and
other ownership rights conveyed pursuant to this Agreement

         5.4      No Conflict. Each Party represents and warrants to the other
that it has not entered, and will not enter, into any agreement with any Third
Party which is in conflict with the rights granted to the other Party under this
Agreement, and has not taken and will not take any action that would in any way
prevent it from granting the rights granted to the other Party under this
Agreement, or that would otherwise materially conflict with or adversely affect
the rights granted to the other Party under this Agreement.

         5.5      No Approvals or Consents Required. Each Party represents and
warrants to the other that all necessary consents, approvals and authorizations
of all governmental authorities and other persons or entities required to be
obtained by such Party in order to enter into this Agreement have been obtained.

         5.6      Patents. Gilead represents and warrants to EyeTech that in
Exhibit D, Gilead has in good faith supplied a complete list of all Patents it
Controls as of the Effective Date, that, but for the grant of the License, would
be infringed by the manufacture, use or sale of Products in the Field. If
EyeTech reasonably determines that any Patent Controlled by Gilead or any
Affiliate of Gilead as of the Effective Date should be added to Exhibit D
because EyeTech's manufacture, use or sale of Products would infringe such
Patent, then there shall be no deemed breach of Gilead's representations and
warranties in this Section 5.6 until after the parties negotiate in good faith
regarding the addition of any such Patent to Exhibit D without any additional
financial obligation and are unable to reach agreement on such addition of such
Patent.

         5.7      No Conflict. Each Party represents and warrants to the other
that the execution and delivery of the Agreement by such Party and the
performance of such Party's obligations

                                      15.
<PAGE>

hereunder (a) do not conflict with or violate any requirement of applicable law
or regulation or any provision of articles of incorporation or bylaws of such
Party in any material way, and (b) do not conflict with, violate or breach or
constitute a default or require any consent under, any contractual obligation or
court or administrative order by which such Party is bound.

         5.8      Regulatory Documents. Gilead represents and warrants to
EyeTech that:

                  (a)      Gilead has furnished EyeTech with access to a
complete copy of the United States Regulatory Documents for the Product,
including all material amendments and supplements thereto;

                  (b)      the Regulatory Documents have been accepted by, and
Gilead has received no notice that the Regulatory Documents are not in good
standing with, the relevant Regulatory Authorities;

                  (c)      to its knowledge, Gilead has filed with the relevant
Regulatory Authorities all required notices, supplemental applications and
annual or other reports, including adverse experience reports, with respect to
the Regulatory Documents which are material;

                  (d)      Gilead has received no written notice of any
regulatory action by the relevant Regulatory Authorities which may reasonably be
expected to have a material adverse effect on the ability of a Party to obtain
Regulatory Approval for Products based upon the Regulatory Documents.

         5.9      Manufacturing Information. Gilead represents and warrants
that, it has delivered or shall by the Delivery Date deliver to EyeTech all of
the Transferred Assets and the Manufacturing Information.

         5.10     Product Quality. Gilead hereby represents and warrants that
all Product Inventory that is provided to EyeTech pursuant to the terms of this
Agreement has been manufactured in compliance with all laws, rules and
regulations (including without limitation, all applicable IND applications)
applicable to the conduct of Gilead's Phase I clinical trial for a Product.

         5.11     Implied Warranties. EXCEPT AS EXPRESSLY PROVIDED IN THIS
SECTION 5, GILEAD MAKES NO REPRESENTATION OR WARRANTY AS TO THE PATENTS,
LICENSED PATENTS, KNOW-HOW, THE TRANSFERRED ASSETS, PRODUCTS, ITS INVENTORY OF
PRODUCTS OR NX1838, EXPRESS OR IMPLIED, EITHER IN FACT OR BY OPERATION OF LAW,
BY STATUTE OR OTHERWISE, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY RIGHTS, OR OTHERWISE, AND GILEAD SPECIFICALLY DISCLAIMS ANY AND ALL
IMPLIED OR STATUTORY WARRANTIES. Without limiting the foregoing, EyeTech
acknowledges that it has not and is not relying upon any implied warranty,
including without limitation implied warranties of merchantability, fitness for
a particular purpose, non-infringement of third party rights, or upon any
representation or warranty whatsoever as to the prospects (financial, regulatory
or otherwise), or the validity or likelihood of success, of any Product after
the Effective Date.

                                      16.
<PAGE>

                                    SECTION 6
               ADDITIONAL COVENANTS AND AGREEMENTS OF THE PARTIES

         6.1      Governmental Filings. Gilead and EyeTech each agree to prepare
and file whatever filings, requests or applications are required to be filed
with any governmental authority in connection with this Agreement and to
cooperate with one another as reasonably necessary to accomplish the foregoing.
Without limiting the generality of the foregoing, prior to, or within five (5)
Business Days following, the assignment, transfer and conveyance by Gilead to
EyeTech of the Transferred Assets pursuant to Section 2.2, Gilead shall have
submitted to the relevant Regulatory Authorities the information required of a
former owner of regulatory filings with respect to the Product, and EyeTech
shall submit to the relevant Regulatory Authorities the information required of
a new owner of regulatory filings with respect to the Product.

         6.2      Compliance with Law. EyeTech shall comply with all
supranational, national, federal, state, provincial and other local laws and
regulations applicable to EyeTech's manufacture, use, development, marketing and
sale of the Product. Without limiting the generality of the foregoing sentence,
EyeTech shall not promote the Product in any manner in conflict with any
applicable laws or regulations.

         6.3      Proprietary Information; Exceptions. Each Party will maintain
all Proprietary Information received by it under this Agreement in trust and
confidence and will not disclose any such Proprietary Information to any Third
Party or use any such Proprietary Information for any purposes other than those
necessary or permitted for performance under this Agreement. In particular,
EyeTech shall not use any Know How for the manufacture or sale of any product
other than a Product in the Field. Each Party may use such Proprietary
Information only to the extent required to accomplish the purposes of this
Agreement. Proprietary Information shall not be used for any purpose or in any
manner that would constitute a violation of any laws or regulations, including
without limitation the export control laws of the United States. Proprietary
Information shall not be reproduced in any form except as required to accomplish
the intent of this Agreement. No Proprietary Information shall be disclosed to
any employee, agent, consultant, Affiliate, or sublicensee who does not have a
need for such information. To the extent that disclosure is authorized by this
Agreement, the disclosing Party will obtain prior agreement, from its employees,
directors, agents, consultants, Affiliates, sublicensees or clinical
investigators to whom disclosure is permitted to be made, to obligations to hold
in confidence and not make use of such information for any purpose other than
those permitted by this Agreement, that are at least as restrictive as those of
this Section 6.3. Each Party will use at least the same standard of care as it
uses to protect its own Proprietary Information of a similar nature to ensure
that such employees, agents, consultants and clinical investigators do not
disclose or make any unauthorized use of such Proprietary Information, but no
less than reasonable care. Each Party will notify the other within two (2)
Business Days upon discovery of any unauthorized use or disclosure of the
Proprietary Information.

         Proprietary Information shall not include any information which, as
shown by competent proof:

                  (a)      is now, or hereafter becomes, through no act or
failure to act on the part of the receiving Party, its employees or contractors
in breach hereof, generally known or available;

                                      17.
<PAGE>

                  (b)      is known by the receiving Party at the time of
receiving such information, as evidenced by its contemporaneous written records;

                  (c)      is hereafter furnished to the receiving Party by a
Third Party, as a matter of right and without restriction on disclosure;

                  (d)      is independently developed by the receiving Party
without any breach of this Agreement, as shown by independent, contemporaneous,
written records; or

                  (e)      is the subject of a prior, express, written
permission to disclose provided by the disclosing Party.

         Notwithstanding any other provision of this Section 6.3, (i) the
Parties agree that they shall issue a press release in the form attached hereto
as Exhibit F, and (ii) either Party may disclose such terms to bona fide
potential corporate partners, to the extent required or contemplated by this
Agreement, and to financial underwriters and other Third Parties with a need to
know such information, provided that all such disclosures shall be made only to
such Third Parties under an obligation of confidentiality and appropriately
limited use.

         6.4      Authorized Disclosure. Notwithstanding any other provision of
this Agreement, each Party may disclose Proprietary Information if such
disclosure:

                  (a)      is in response to a valid order of a court or other
governmental body of the United States or a foreign country, or any political
subdivision thereof; provided, however, that the receiving Party shall first
have given notice to the other Party hereto and shall have made a reasonable
effort to obtain a protective order requiring that the Proprietary Information
so disclosed be used only for the purposes for which the order was issued;

                  (b)      is otherwise required by governmental law, rule or
regulation, including without limitation rules or regulations of the U.S.
Securities and Exchange Commission, or by rules of the National Association of
Securities Dealers; or

                  (c)      is otherwise necessary to file or prosecute patent
applications, prosecute or defend litigation or comply with applicable
governmental regulations or otherwise establish rights or enforce obligations
under this Agreement, but only to the extent that any such disclosure is
necessary. Under no circumstances will EyeTech disclose publicly proprietary
features of Gilead manufacturing technology for NX1838; provided, however, that
Gilead shall cooperate with EyeTech to disclose such information to the extent
required to provide EyeTech with reasonable protection from liability by reason
of this prohibition on disclosure.

         6.5      Return of Proprietary Information. In the event that the
License terminates or expires, EyeTech shall promptly return all Proprietary
Information received by it from Gilead.

         6.6      Expenses. Gilead and EyeTech shall each bear their own direct
and indirect expenses incurred in connection with the negotiation and
preparation of this Agreement and, except as set forth in this Agreement, the
performance of the obligations contemplated hereby.

                                      18.
<PAGE>

         6.7      Efforts.

                  (a)      EyeTech shall use Reasonable Diligence to develop,
obtain Regulatory Approval for, and commercialize Product(s) in the Territory
and shall be solely responsible for all related development, regulatory and
commercialization efforts and costs; provided, however, with respect to
countries in the Territory that are not Major Countries (such countries,
"Non-Major Countries"), EyeTech shall have the right to determine, on a country
by country basis using its reasonable discretion not to pursue Regulatory
Approval in such Non-Major Country because commercialization of the Product is
not economically feasible for EyeTech. EyeTech shall provide Gilead with written
notice of all decisions by EyeTech to not pursue development, Regulatory
Approval or commercialization in a country in the Territory for a Product in the
Field for any reason within thirty (30) days of such decision.

                  (b)      In the event EyeTech or its sublicensees fail to
undertake Reasonable Diligence in developing, obtaining Regulatory Approval of,
and/or commercializing Products in one or more Major Countries in the Territory,
such failure shall (i) automatically cause the License to terminate with respect
to such Major Country(ies) and have the consequences set forth in Section 4.5(c)
with respect to any such Major Country(ies); and (ii) shall entitle Gilead to
terminate this Agreement for material breach under Section 4.3 if there have
been such failures of diligence applying to four (4) or more Major Countries,
with the consequences set forth in Section 4.5(c); provided in each case that
EyeTech (or its sublicensee) does not cure such failure within ninety (90) days
of written notice from Gilead specifying its belief that such failure has
occurred and the reasons therefor. Gilead shall not be entitled to exercise the
foregoing termination rights if EyeTech reasonably disputes Gilead's contention
that EyeTech has failed in such Reasonable Diligence until after the Parties
have first completed dispute resolution procedures pursuant to Section 8.9.

                  (c)      EyeTech's Responsibilities. EyeTech shall be
responsible, at its sole expense, for all development of, regulatory activities
relating to, and commercialization of Products in the Territory beginning on the
Effective Date, including performing clinical development of Products within the
Territory using standard pharmaceutical industry practices, and making all
regulatory filings necessary to obtain Regulatory Approvals of Products in the
Territory. Within thirty (30) days of the Effective Date, EyeTech shall provide
to Gilead a formal clinical development plan for Products in the Field in the
Territory (the "Development Plan"), pursuant to which EyeTech will carry out
development of Products under this Agreement, which shall be reasonably
satisfactory to Gilead. The Development Plan shall be subject to amendment by
EyeTech from time to time, with notice and copy of such amended Development Plan
to Gilead; provided, however, (i) Gilead shall have the right to review such
proposed amendment prior to its adoption; (ii) EyeTech shall in good faith
consider any reasonable comments and considerations raised by Gilead within five
(5) Business Days of Gilead's receipt of such proposed amendment; and (iii) such
proposed amendment is consistent with EyeTech's obligations of Reasonable
Diligence pursuant to Sections 6.7(a) and (b).

                  (d)      Regulatory Filings and Matters. EyeTech will file
such regulatory filings as may be necessary to obtain Regulatory Approvals of
Products within the Territory. EyeTech will be responsible for all
communications with all supranational, regional, federal, state, provincial or
other local regulatory agencies, department, bureaus and other governmental

                                      19.
<PAGE>

authorities with jurisdiction over Regulatory Approvals in connection with such
filings. EyeTech will keep Gilead informed of the status of such filings in each
country, and will provide Gilead with at least sixty (60) days advance notice of
the final submission of an application for Regulatory Approval in any country of
the Territory. EyeTech will promptly advise Gilead each time that it obtains
Regulatory Approval of Products in a country of the Territory. EyeTech shall be
responsible for the reporting of adverse events related to the use of Products
marketed by EyeTech, its Affiliates or sublicensees in the Territory.

                  (e)      Reporting; Meetings. Prior to February 1, May 1,
August 1 and November 1 of each Calendar Year, EyeTech will submit to Gilead,
written reports summarizing the status and progress of the clinical development,
marketing and commercialization efforts for each Product in sufficient detail so
as to allow Gilead to monitor EyeTech's compliance with Section 6.7(a). During
March and September of each Calendar Year, senior executive and scientific
personnel of EyeTech will meet with Gilead representatives to report on the
status of development and commercialization of Products and to consult as to
modifications in the development plan referenced in Section 6.7(c).

         6.8      Pricing. EyeTech shall determine, in its sole discretion, the
pricing, discounting policy and other commercial terms relating solely to
Products. EyeTech agrees that EyeTech, its Affiliates and its sublicensees shall
not subject the selling price of Products to abnormal discounts taken against
Products in order to achieve sales of other products.

         6.9      Export Control. This Agreement is made subject to any
restrictions concerning the export of products or technical information from the
United States of America or other countries which may be imposed upon or related
to Gilead or EyeTech from time to time. Each Party agrees that it will not
export, directly or indirectly, any technical information acquired from the
other Party under this Agreement or any products using such technical
information to a location or in a manner that at the time of export requires an
export license or other governmental approval, without first obtaining the
written consent to do so from the appropriate agency or other governmental
entity.

         6.10     Inability to Develop or Commercialize. EyeTech represents that
it has, and covenants that it will maintain adequate resources and expertise to
fulfill its obligations under this Agreement. During the term of this Agreement,
EyeTech shall provide such information that Gilead may request that is
reasonably necessary for Gilead to verify that EyeTech has adequate resources
and expertise to fulfill its obligations under this Section 6.10.

                                      20.
<PAGE>

         6.11     Compliance with Laws; Cooperation; Maintenance of Original
Documents.

                  (a)      Each Party shall carry out its activities pursuant to
this Agreement in compliance with all applicable supranational, national, state,
provincial and local laws, rules, regulations and guidances.

                  (b)      Gilead and EyeTech each agree to use all commercially
reasonable efforts to take, or cause to be taken, all actions and to do, or
cause to be done, all things necessary or proper to make effective the
transactions contemplated by this Agreement, including such actions as may be
reasonably necessary to obtain approvals and consents of governmental Persons
and other Persons (including, without limitation, all applicable drug listing
and notifications to the relevant Regulatory Authority identifying EyeTech as
the licensee of the Product), in each case as reasonably necessary to allow
EyeTech to develop, obtain Regulatory Approvals for, and commercialize Products
as provided in this Agreement; provided that no Party shall be required in
connection with such activities to (1) make any payment (other than as expressly
required pursuant to this Agreement), or (2) assume any other material
obligation not otherwise required to be assumed by this Agreement.

                  (c)      For so long as EyeTech, its Affiliates or
sublicensees is making, using or selling Products, Gilead shall store and
maintain all original Manufacturing Information in a secure location in
accordance with practices customary for Gilead and the pharmaceutical industry
for regulatory documents and in compliance with applicable laws and regulations,
and, upon proper notice from a Regulatory Authority of competent jurisdiction
over Products, shall make such Manufacturing Information reasonably available to
such Regulatory Authority.

                  (d)      EyeTech shall store and maintain all original Updated
Product Data Package in a secure location in accordance with practices customary
for EyeTech and the pharmaceutical industry for regulatory documents and in
compliance with applicable laws and regulations.

         6.12     Cooperation. If either Party shall become engaged in or
participate in any investigation, claim, litigation or other proceeding with any
Third Party, including any proceeding before a Regulatory Authority, relating in
any way to the Product or any of the Licensed Patents the other Party shall
cooperate in all reasonable respects with such Party in connection therewith,
including, without limitation, using its reasonable efforts to make available to
the other Party such Party's employees who may be helpful with respect to such
investigation, claim, litigation or other proceeding, provided that, for
purposes of this provision, reasonable efforts to make available any employee
shall be deemed to mean providing a Party with reasonable access to any such
employee at no cost for a period of time not to exceed 24 hours (e.g., three
8-hour Business Days). Thereafter, any such employee shall be made available for
such time and upon such terms and conditions (including, but not limited to,
compensation) as the Parties may mutually agree.

         6.13     Exclusive Rights. The licenses granted under this Agreement to
EyeTech are exclusive, and no Person, including without limitation Gilead, shall
have any right with respect to such licenses during the term of this Agreement,
except as otherwise permitted under this Agreement. Except as otherwise
permitted by this Agreement, Gilead shall refrain from granting

                                      21.
<PAGE>

any right to any Third Party relating to NX1838, the Licensed Patents or the
Transferred Assets that would, in any manner, violate the terms of or conflict
with the rights granted to EyeTech pursuant to this Agreement.

         6.14     Patent Prosecution and Maintenance.

                  (a)      Prosecution of Patents. Licensed Patents shall be
prosecuted and maintained in the Territory by Gilead using diligent efforts, at
Gilead's expense, except as otherwise provided in this Section 6.14(a). If
Gilead reasonably determines that it has no material or commercially useful
application for a Licensed Patent, then EyeTech shall have the right to have
Gilead prosecute and maintain such Licensed Patents or file for such patent term
extension therefor at EyeTech's sole expense. EyeTech shall bear all reasonable
costs of any inter partes patent proceeding, including without limitation
oppositions, interferences or contested re-examinations, which proceeding shall
be conducted under the control of Gilead.

                  (b)      EyeTech shall assist Gilead in obtaining patent
extensions and supplementary protection certificates, and provide such other
assistance as reasonably requested by Gilead in connection with the prosecution
and maintenance of the Licensed Patents in any part of the Territory at
EyeTech's sole expense.

         6.15     Infringement of Licensed Patents.

                  (a)      Notice. Each Party shall promptly notify the other in
writing of any alleged infringement by Third Parties of any Licensed Patent
within the Territory and provide any information available to that Party
relating to such alleged infringement or misappropriation. EyeTech shall have no
rights with respect to any infringement of Licensed Patents that occurs outside
of the Field and/or outside the Territory except the right to receive notice
pursuant to this Section 6.15(a).

                  (b)      Enforcement of Licensed Patents against Competitive
Products. If any Licensed Patent is infringed by a Third Party in connection
with the manufacture, use, sale, offer for sale or import of a Competitive
Product within the Field and within the Territory ("Competitive Product
Infringement"), EyeTech shall have the primary right, but not the obligation, to
initiate, prosecute and control any action with respect to such infringement in
the Territory, by counsel of its own choice, to secure the cessation of the
infringement or to enter suit against the infringer. Gilead shall have the right
to participate in any such action with respect to the Licensed Patents and to be
represented by counsel of its own choice. If EyeTech fails to bring an action or
proceeding to enforce a Licensed Patent within a period of one hundred twenty
(120) days after having knowledge of infringement of such Licensed Patent, then
Gilead shall have the right to bring and control any such action by counsel of
its own choice, and EyeTech shall have the right to participate in such action
and be represented by counsel of its own choice. If a Party brings any such
action or proceeding under this Section 6.15(b), the other Party agrees to be
joined as a party plaintiff and to give the first Party reasonable assistance
and authority to control, file and prosecute the suit as necessary. The costs
and expenses of the Party bringing suit under this Section 6.15(b) (including
the internal costs and expenses specifically attributable to such suit) shall be
reimbursed first out of any damages or other monetary awards recovered in favor
of the Parties, and any remaining damages shall be treated as Net Sales of

                                      22.
<PAGE>

EyeTech in its Territory if EyeTech controlled the action or allocated between
the parties in accordance with their economic interest in the profitability of
Products if Gilead controlled the action. No settlement or consent judgment or
other voluntary final disposition of a suit under this Section 6.15(b) relating
to a Licensed Patent may be entered into without the consent of Gilead, not to
be unreasonably withheld.

                  (c)      Enforcement of Licensed Patents against
Non-Competitive Products. With respect to any infringement of Licensed Patents
within the Field and within the Territory that is not a Competitive Product
Infringement, Gilead shall have the primary right, but not the obligation, to
initiate, prosecute and control any action with respect to such infringement, by
counsel of its own choice, to secure the cessation of the infringement or to
enter suit against the infringer and shall be the "Lead Party" and EyeTech shall
be the "Secondary Party". The Secondary Party shall have the right to
participate in any such action with respect to its Patents and to be represented
by counsel of its own choice. If the Lead Party fails to bring an action or
proceeding to enforce a Licensed Patent within a period of one hundred twenty
(120) days after having knowledge of infringement of such Licensed Patent, then
the Secondary Party shall have the right to bring and control any such action by
counsel of its own choice, and the Lead Party shall have the right to
participate in such action and be represented by counsel of its own choice. If a
Party brings any such action or proceeding hereunder, the other Party agrees to
be joined as a party plaintiff and to give the first Party reasonable assistance
and authority to control, file and prosecute the suit as necessary. The costs
and expenses of the Party bringing suit under this Section 6.15(c) (including
the internal costs and expenses specifically attributable to such suit) shall be
reimbursed first out of any damages or other monetary awards recovered in favor
of the Parties, and any remaining damages shall be paid to Gilead if Gilead
controlled the action, or paid to each Party in proportion to their expenditures
in such action, if EyeTech controlled the action. No settlement or consent
judgment or other voluntary final disposition of a suit under this Section
6.15(c) relating to a Licensed Patent may be entered into without the consent of
Gilead, not to be unreasonably withheld.

         6.16     Infringement of Third Party's Rights.

                  (a)      If the practice of the Licensed Patents through the
manufacture, use or sale of Products by EyeTech, its Affiliates or sublicensees
results in a claim for patent infringement against EyeTech, its Affiliates or
sublicensees, the Party to this Agreement first having notice of that claim
shall promptly notify the other Party in writing. The notice shall set forth the
facts of the claim in reasonable detail.

                  (b)      If a Third Party asserts that a patent or other right
owned by or licensed to it is infringed by the practice of the Licensed Patents
through the manufacture, use or sale of Products by EyeTech, its Affiliates or
sublicensees pursuant to the License, EyeTech may attempt to resolve the problem
raised by the asserted infringement. The matter shall be deemed resolved if
EyeTech obtains: (a) a license permitting EyeTech to manufacture, use and sell
Products in that country on a royalty-free or royalty-bearing basis; (b) a
statement or representation from the Third Party that: (1) no action will be
taken against EyeTech, its Affiliates or its sublicensees, or (2) that the
patent or other right is not infringed by the manufacture, use or sale of
Products by EyeTech, its Affiliates or its sublicensees; or (c) a final judgment
by a court of competent jurisdiction from which no appeal has or can be taken
that the

                                      23.
<PAGE>

Third Party's patent(s) alleged to be infringed is invalid, or the Third Party's
patent(s) or other right(s) are unenforceable or not infringed by the
manufacture, use or sale of Products by EyeTech, its Affiliates or sublicensees.
EyeTech shall have the primary right to defend any such claim. Gilead shall have
the right, but not the obligation, to participate in any such suit at its sole
option and at its own expense. Each Party shall reasonably cooperate with the
Party conducting the defense of the claim. Neither Party shall enter into any
settlement that affects the other Party's rights or interests without such other
Party's prior written consent, not to be unreasonably withheld. If EyeTech makes
a payment to any Third Party in the course of defending or settling any claim
brought by a Third Party pursuant to this Section 6.16, EyeTech shall be
entitled to offset a percentage of all such amounts against royalties due to
Gilead hereunder as provided in Section 3.3(b).

         6.17     Manufacturing.

                  (a)      EyeTech shall be solely responsible for the
manufacture of Product following the Effective Date, including without
limitation for clinical trials and commercialization.

                  (b)      The Parties shall enter into an agreement dated as of
the Effective Date (the "Manufacturing Agreement") obligating the Parties to
enter into a clinical supply agreement providing for the fill and finish of
sufficient quantities of Product Inventory to complete a Phase Ib trial
investigating the use of NX1838 for the treatment of age-related macular
degeneration.

         6.18     Use of Names, Logos or Symbols. No Party hereto shall use the
name, trademarks, logos, physical likeness, employee names or owner symbol of
the other Party hereto for any purpose, including, without limitation, in
connection with any private or public securities placements, without the prior
written consent of the affected Party, such consent not to be unreasonably
withheld or delayed so long as such use of name is limited to objective
statements of fact, rather than for endorsement purposes. Nothing contained
herein shall be construed as granting either Party any rights or license to use
any of the other Party's trademarks or trade names without separate, express
written permission of the owner of such trademark or trade name.

                                    SECTION 7
                                 INDEMNIFICATION

         7.1      Indemnification.

                  (a)      Gilead shall indemnify, defend and hold EyeTech (and
its directors, officers, employees, consultants, Affiliates and sublicensees)
(each, an "EyeTech Indemnitee") harmless from and against any and all Damages
incurred or suffered by an EyeTech Indemnitee as a result of Third Party claims,
actions or proceedings (collectively, "EyeTech Claims") to the extent such
EyeTech Claims are a consequence of:

                                    (1)      the breach or alleged breach of any
representation or warranty by Gilead hereunder, or

                                      24.
<PAGE>

                                    (2)      the negligence or misconduct of
Gilead in connection with its activities under this Agreement;

except to the extent such EyeTech Claims are a consequence any of the items in
Sections 7.1(b)(1), (2) or (3).

                  (b)      EyeTech shall indemnify, defend and hold Gilead (and
its directors, officers, employees, consultants and Affiliates) (each, a "Gilead
Indemnitee") harmless from and against any and all Damages incurred or suffered
by a Gilead Indemnitee as a result of Third Party claims, actions or proceedings
(collectively, "Gilead Claims") to the extent such Gilead Claims are a
consequence of:

                                    (1)      the breach or alleged breach of any
representation or warranty by EyeTech hereunder;

                                    (2)      the negligence or willful
misconduct of EyeTech in connection with its activities under this Agreement;

                                    (3)      the possession, research,
development, manufacture, use, offer for sale, sale, administration, storage or
transport of NX1838 or Products by EyeTech or its Affiliates or sublicensees;

except to the extent such Gilead Claims are a consequence any of the items in
Sections 7.1(a)(1) or (2).

         7.2      Mechanics. If a Party or its Affiliate has a right to be
indemnified under this Section 7 (the "Indemnified Party"), such Party or
Affiliate (i) shall give prompt notice of such EyeTech Claim or Gilead Claim, as
the case may be (as applicable, a "Claim"), to the other Party (the
"Indemnifying Party") and (ii) subject to Sections 6.15 and 6.16 of this
Agreement, will have the first right to defend any Claims for which it is
entitled to indemnification from the other Party under Section 7.1, with the
cooperation and at the expense of such other Party, provided that it will not
settle any such Claim without the prior written consent of the Indemnifying
Party, which consent shall not be unreasonably withheld. If the Indemnified
Party is defending a Claim, the Indemnifying Party shall have the right to be
present in person or through counsel at substantive legal proceedings. In the
event that the Parties cannot agree as to the application of Section 7.1 to any
Damages or Claim, the Parties may conduct separate defenses of such claim. Each
Party further reserves the right to claim indemnity from the other in accordance
with Section 7.1 upon resolution of the underlying claim.

         7.3      Insurance Coverage. Each Party represents and warrants that it
is covered and will continue to be covered by a comprehensive general liability
insurance program which covers all of each Party's activities and obligations
hereunder in accordance with reasonable pharmaceutical industry standards. Each
Party will provide the other Party with written notice at least fifteen (15)
days prior to any cancellation or material change in such insurance program.
Each Party will maintain such insurance program, or other program with
comparable coverage, beyond the expiration or termination of this Agreement
during the period in which any Product is being commercially distributed or
sold, and for a commercially reasonable period thereafter.

                                      25.
<PAGE>

         7.4      Indemnification Payment Adjustments. The amount of any Damages
for which indemnification is provided under this Section 7 shall be reduced to
take account of any net tax benefit and shall be increased to take account of
any net tax detriment arising from the incurrence or payment of any such Damages
or from the receipt of any such indemnification payment and shall be reduced by
the insurance proceeds received and any other amount recovered, if any, by the
Indemnified Party with respect to any Damages; provided, however, that an
Indemnified Party shall not be subject to an obligation to pursue an insurance
claim relating to any Damages for which indemnification is sought hereunder. If
any Indemnified Party shall have received any payment pursuant to this Section 7
with respect to any Damages and shall subsequently have received insurance
proceeds or other amounts with respect to such Damages, then such Indemnified
Party shall pay to the Indemnifying Party an amount equal to the difference (if
any) between (1) the sum of the amount of those insurance proceeds or other
amounts received and the amount of the payment by such Indemnifying Party
pursuant to this Section 7 with respect to such Damages and (2) the amount
necessary to fully and completely indemnify and hold harmless such Indemnified
Party from and against such Damages; provided, however, in no event will such
Indemnified Party have any obligation pursuant to this sentence to pay to such
Indemnifying Party an amount greater than the amount of the payment by such
Indemnifying Party pursuant to this Section 7 with respect to such Damages.

         7.5      Indemnification Payment. Upon the final determination of
liability and the amount of the indemnification payment under this Section 7,
the appropriate Party shall pay to the other in immediately available funds,
within thirty (30) Business Days after such determination, the amount of any
claim for indemnification made hereunder.

         7.6      Survival. The provisions of this Section 7 shall survive any
termination of this Agreement with respect to actions of the Parties during the
term of the Agreement or the term of any license to EyeTech, whichever occurs
later. Each Indemnified Party's rights under this Section 7 shall not be deemed
to have been waived or otherwise affected by such Indemnified Party's waiver of
the breach of any representation, warranty, agreement or covenant contained in
or made pursuant to this Agreement, unless such waiver expressly and in writing
also waives any or all of the Indemnified Party's right under Section 7.

                                    SECTION 8
                                  MISCELLANEOUS

         8.1      Successors and Assigns. This Agreement shall be binding upon
and shall inure to the benefit of the Parties hereto and their respective
successors and assigns; provided, however, that neither Gilead nor EyeTech may
assign any of its rights, duties or obligations hereunder without the prior
written consent of the other, which consent may be withheld in the other's sole
discretion, except that no prior written consent shall be required in the event
that a Third Party acquires substantially all of the assets or outstanding
shares of, or merges with, EyeTech or Gilead, as the case may be. No assignment
of this Agreement or of any rights hereunder shall relieve the assigning Party
of any of its obligations or liability hereunder. Any attempted assignment not
in compliance with this Section 8.1 shall be of no force or effect.

         8.2      Notices. All notices or other communications required or
permitted to be given hereunder shall be in writing and shall be deemed to have
been duly given if delivered by hand,

                                      26.
<PAGE>

prepaid telex, cable, telegram or facsimile and confirmed in writing, or mailed
first class, postage prepaid, by registered or certified mail, return receipt
requested (mailed notices and notices sent by telex, cable or telegram shall be
deemed to have been given on the date received) as follows:

                               If to Gilead, as follows:

                               Gilead Sciences, Inc.
                               333 Lakeside Drive,
                               Foster City, CA 94404
                               Facsimile: (650) 522-5488
                               Attn: Chief Executive Officer

                               With a copy to:

                               Gilead Sciences, Inc.
                               333 Lakeside Drive,
                               Foster City, CA 94404
                               Facsimile: (650) 522-5537
                               Attn: General Counsel

                               If to EyeTech, as follows:

                               EyeTech Pharmaceuticals, Inc.
                               300 East 42nd Street
                               Third Floor
                               New York, N.Y. 10017
                               Facsimile: (212) 883-8883
                               Attn: Chief Executive Officer

                               With a copy to:

                               Duval & Stachenfeld LLP
                               300 East 42nd Street
                               Third Floor
                               New York, N.Y. 10017
                               Facsimile: (212) 883-8883
                               Attn: Harsha Murthy

or in any case to such other address or addresses as hereafter shall be
furnished as provided in this Section 8.2 by any Party hereto to the other
Party.

         8.3      Waiver; Remedies. Any term or provision of this Agreement may
be waived at any time by the Party entitled to the benefit thereof by a written
instrument executed by such Party. No delay on the part of Gilead or EyeTech in
exercising any right, power or privilege hereunder shall operate as a waiver
thereof, nor shall any waiver on the part of either Gilead or EyeTech of any
right, power or privilege hereunder operate as a waiver of any other right,
power or privilege hereunder nor shall any single or partial exercise of any
right, power or privilege

                                      27.
<PAGE>

hereunder preclude any other or further exercise thereof or the exercise of any
other right, power or privilege hereunder.

         8.4      Survival of Representations. Each of the representations and
warranties made in this Agreement shall survive the expiration or termination of
this Agreement only with respect to activities conducted or events occurring
prior to the expiration or termination of the Agreement.

         8.5      Entire Agreement. This Agreement, together with all exhibits
hereto and the Warrant Agreement and the Manufacturing Agreement, constitute the
entire agreement between the Parties with respect to the subject matter hereof
and supersedes all prior agreements or understandings of the Parties relating
thereto.

         8.6      Amendment. This Agreement may be modified or amended only by
written agreement of the Parties hereto.

         8.7      Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original but all of which
together shall constitute a single instrument.

         8.8      Governing Law. This Agreement shall be governed and construed
in accordance with the laws of the State of California, excluding its choice of
law rules, except for the application of the Federal Arbitration Act pursuant to
Section 8.9(c)(ii).

         8.9      Dispute Resolution.

                  (a)      The Parties recognize that disputes as to certain
matters may from time to time arise during the term of this Agreement which
relate to either party's rights and/or obligations hereunder or thereunder. It
is the objective of the Parties to establish procedures to facilitate the
resolution of disputes arising under this Agreement in an expedient manner by
mutual cooperation and without resort to litigation. To accomplish this
objective, the Parties agree to follow the procedures set forth in this Section
8.9 if and when a dispute arises under this Agreement. In the event of disputes
between the Parties, a Party seeking to resolve such dispute will, by written
notice to the other Party, have such dispute referred to their respective
executive officers designated below or their successors, for attempted
resolution by good faith negotiations within fourteen (14) days after such
notice is received. Said designated officers are as follows:

                  For EyeTech:      Chief Executive Officer
                  For Gilead:       Chief Executive Officer

         In the event the designated executive officers are not able to resolve
such dispute, either party may at any time after the 14 day period invoke the
provisions of Section 8.9(b) hereinafter.

                  (b)      Following settlement efforts pursuant to Section
8.9(a), any dispute, controversy or claim arising out of or relating to the
validity, construction, enforceability or performance of this Agreement,
including disputes relating to alleged breach or to termination of this
Agreement under Section 4, other than disputes which are expressly prohibited
herein from

                                      28.
<PAGE>

being resolved by this mechanism, shall be settled by binding Alternative
Dispute Resolution ("ADR") in the manner described below:

                           (i)      If a party intends to begin an ADR to
resolve a dispute, such party shall provide written notice (the "ADR Request")
to counsel for the other party informing such other party of such intention and
the issues to be resolved. From the date of the ADR Request and until such time
as any matter has been finally settled by ADR, the running of the time periods
contained in Section 4.3 as to which party must cure a breach of this Agreement
shall be suspended as to the subject matter of the dispute.

                           (ii)     Within ten (10) business days after the
receipt of the ADR Request, the other party may, by written notice to the
counsel for the party initiating ADR, add additional issues to be resolved.

                           (iii)    Disputes regarding the scope, validity and
enforceability of Patents shall not be subject to this Section 8.9, except for
Section 8.9(a), and shall be submitted to a court of competent jurisdiction.

                  (c)      The ADR shall be conducted pursuant to Comprehensive
Rules for Commercial, Real Estate and Construction Disputes then in effect,
except that notwithstanding those rules, the following provisions shall apply to
the ADR hereunder:

                           (i)      The arbitration shall be conducted by a
panel of three arbitrators (the "Panel"). The Panel shall be selected from a
pool of retired independent federal judges to be presented to the Parties by
JAMS.

                           (ii)     The time periods set forth in the JAMS rules
shall be followed, unless a party can demonstrate to the Panel that the
complexity of the issues or other reasons warrant the extension of one or more
of the time tables. In such case, the Panel may extend such time tables, but in
no event shall the time tables being extended so that the ADR proceeding extends
more than 18 months from its beginning to the Award. In regard to such time
tables, the Parties (i) acknowledge that the issues that may arise in any
dispute involving this Agreement may involve a number of complex matters and
(ii) confirm their intention that each party will have the opportunity to
conduct complete discovery with respect to all material issues involved in a
dispute within the framework provided above. Within such time frames, each party
shall have the right to conduct discovery in accordance with the Federal Rules
of Civil Procedure. The Panel shall not award punitive damages to either party
and the Parties shall be deemed to have waived any right to such damages. The
Panel shall, in rendering its decision, apply the substantive law of the State
of California, without regard to its conflict of laws provisions, except that
the interpretation of and enforcement of this Section 8.9(c)(ii) shall be
governed by the Federal Arbitration Act. The Panel shall apply the Federal Rules
of Evidence to the hearing. The proceeding shall take place in San Francisco,
San Mateo or Santa Clara Counties, California. The fees of the Panels and JAMS
shall be paid by the losing Party which shall be designated by the Panel. If the
Panel is unable to designate a losing party, it shall so state and the fees
shall be split equally between the Parties.

                                      29.
<PAGE>

                           (iii)    The Panel is empowered to award any remedy
allowed by law, including money damages, multiple damages, prejudgment interest
and attorneys' fee, and to grant final, complete, interim, or interlocutory
relief, including injunctive relief but excluding punitive damages.

                           (iv)     Except as set forth in Section 8.9(c)(ii),
above, each party shall bear its own legal fees. The Panel shall assess its
costs, fees and expenses against the party losing the ADR unless it believes
that neither party is the clear loser, in which case the Panel shall divide such
fees, costs and expenses according to the Panel's sole discretion.

                           (v)      The ADR proceeding shall be confidential and
the Panel shall issue appropriate protective orders to safeguard each party's
Proprietary Information. Except as required by law, no party shall make (or
instruct the Panel to make) any public announcement with respect to the
proceedings or decision of the Panel without prior written consent of each other
party. The existence of any dispute submitted to ADR, and the award, shall be
kept in confidence by the Parties and the Panel, except as required in
connection with the enforcement of such award or as otherwise required by
applicable law.

                  (d)      The Parties agree that judgment on any arbitral award
issued pursuant to this Section 8.9 shall be entered in the United States
District Court for the Northern District of California or, in the event such
court does not have subject matter jurisdiction over the dispute in question,
such judgment shall be entered in the Superior Court of the State of California,
in the County of San Mateo, and each Party agrees to the co-exclusive personal
jurisdiction of such courts for the purpose of entry of such a judgment.

         8.10     Captions. All section titles or captions contained in this
Agreement, in any Exhibit referred to herein and the table of contents, if any,
to this Agreement are for convenience only, shall not be deemed a part of this
Agreement and shall not affect the meaning or interpretation of this Agreement.

         8.11     No Third Party Rights or Obligations. Except as expressly
provided in Section 7, no provision of this Agreement shall be deemed or
construed in any way to result in the creation of any rights or obligation in
any Person not a Party to this Agreement.

         8.12     Severability. If any provision of this Agreement is found or
declared to be invalid or unenforceable by any court or other competent
authority having jurisdiction, such finding or declaration shall not invalidate
any other provision hereof, and this Agreement shall thereafter continue in full
force and effect. In the event any such provision is so declared invalid or
unenforceable, the Parties shall negotiate an alternative provision that closely
approximates the Parties' intent, to the extent allowable under law.

         8.13     Attachments. All Exhibits and other attachments to this
Agreement are by this reference incorporated herein and made a part of this
Agreement.

         8.14     Disclaimer of Agency. This Agreement shall not constitute any
Party the legal representative or agent of another, nor shall any Party have the
right or authority to assume, create, or incur any Third Party liability or
obligation of any kind, express or implied, against or in the name of or on
behalf of another except as expressly set forth in this Agreement.

                                      30.
<PAGE>

         8.15     Interpretation. This Agreement has been jointly prepared by
the Parties and their respective legal counsel and shall not be strictly
construed against either Party.

         8.16     Force Majeure. Each of the Parties hereto shall be excused
from the performance of its obligations hereunder (except the payment of money)
in the event such performance is prevented by force majeure, provided that the
non-performing Party promptly provides notice of the prevention to the other
Party. Such excuse shall be continued so long as the condition constituting
force majeure continues and the non-performing Party makes and continues to make
reasonable efforts to remove or overcome the condition. For the purposes of this
Agreement, force majeure shall mean any act of God, fire, casualty, flood, war,
earthquake, strike, failure of public utilities, any act, exercise, assertion or
requirement of governmental authority, accident, epidemic, destruction of
facilities, or such other similar occurrences beyond the control of the Party
whose performance is affected.

         8.17     Limitation of Liability. IN NO EVENT SHALL EITHER PARTY OR ITS
RESPECTIVE AFFILIATES AND PERMITTED SUBLICENSEES BE LIABLE FOR SPECIAL,
EXEMPLARY, CONSEQUENTIAL OR PUNITIVE DAMAGES, WHETHER IN CONTRACT, WARRANTY,
TORT, STRICT LIABILITY OR OTHERWISE, EXCEPT TO THE EXTENT SUCH PARTY MAY BE
REQUIRED TO INDEMNIFY THE OTHER PARTY FROM SUCH DAMAGES CLAIMED BY THIRD PARTIES
UNDER SECTION 7.

         8.18     No Assumption of Obligations. Except as expressly provided in
this Agreement: (i) neither Party is assuming any of the other Party's
responsibilities, duties (including, without limitation, compliance with all
applicable laws and regulations), obligations (including payment obligations),
claims, Damages, liabilities, burdens and problems of any nature whatsoever
(collectively, "Obligations"), whether by operation of law or otherwise, and
(ii) without limiting the foregoing, EyeTech is not assuming any of Gilead's
Obligations with respect to Transferred Assets.

                                      31.
<PAGE>

         IN WITNESS WHEREOF, the Parties have caused this Agreement to be duly
executed and delivered as of the day and year first above written.

GILEAD SCIENCES, INC.                        EYETECH PHARMACEUTICALS, INC.

By: /s/Mark L. Perry                         By: /s/David Guyer
    ---------------------------------            -------------------------------
    Mark L. Perry                                David Guyer
    Senior Vice President, Operations            Chief Executive Officer

NEXSTAR PHARMACEUTICALS, INC.

By: /s/Mark L. Perry
    ---------------------------------
    Mark L. Perry
    Chief Financial Officer

                                      32.
<PAGE>

                                    EXHIBIT A

                                     NX1838

         The compound NX1838, is [**]

                                      A-1.
<PAGE>

                                    EXHIBIT B

                    PRODUCT DATA PACKAGE INFORMATION AND DATA

           Regulatory
               IND
               Pre-IND submissions
               IND correspondence
               IND supplements

           Clinical
               Case Report Forms by site
               1838 Project Files
               Investigator Files by Site

           Manufacturing (API)
               Synthesis Batch Records
               Accompanying Analytical Data
               Records of Failed Lots

           Manufacturing (DP)
               Master Production Records
               Bills of Materials
               Assay methods
               Finished Product Specifications

                                      B-1.
<PAGE>

                                    EXHIBIT C

                                PRODUCT INVENTORY

NX1838 PHYSICAL COUNT SHEET

                                              DATE: 03/23/00
                                               COUNTED BY: Felicia Yu, Judy Liou

<TABLE>
<CAPTION>
                                                                     Expiration Date     Physical Count
                                                                     ---------------     --------------
<S>                                                                  <C>                 <C>
NX1838 Lots
     LOT# 131901E  3MGS IN 100 MICROLITERS                               2/29/00                 16
     LOT# 141901E  4MGS IN 100 MICROLITERS                              04/13/99                 50
     LOT# 251901E  3MGS IN 200 MICROLITERS                               7/14/99                149

Ingredients
     1106510911    NX 1838 APTAMER           LOT# 97000690              10/14/99              792.8
     1106510911    NX 1838 APTAMER           LOT# 98000122              10/28/99               5441
     1100500911    SODIUM PHOSP MONOBASIC    LOT# 97000299                7/3/02            11527.1
     1100600911    SODIUM PHOSP DIBASIC      LOT# 97000649              12/18/02              11435
     1200110911    SODIUMCHLORIDI            0.9% INJECTION              5/31/00                 20
     1645080911    SYRINGES                  1 ML W/NEEDLE                 03/01               1100

Other clinical batches
     101804E       1/2 MG DOSE EXPIRE 10/99                                10/99                 12
     111803E       1 MG DOSE EXPIRE 10/99                                  10/99                 12
     201901E       1.5 MG PER SYRINGES EXPIRE 07/00                         7/00                 21
     211901E       2.5 MG PER SYRINGES EXPIRE 06/00                         6/00                 25
     151805E       91599400000 EXPIRE 03/99                                 3/99                  3
     121802E       91299400000 EXPIRE 05/99                                 5/99                  2
</TABLE>

                                      C-1.
<PAGE>

                                    EXHIBIT D

                                LICENSED PATENTS

<TABLE>
<S>                        <C>
[**]                       [**]
</TABLE>

                                      D-1.
<PAGE>
                   "[AMENDMENT NO. 1]" TO LICENSING AGREEMENT

     THIS AMENDMENT NO. 1 (the "Amendment") is entered into as of the 9th day
of May, 2000, by and among GILEAD SCIENCES, INC., a Delaware corporation,
NEXSTAR PHARMACEUTICALS, INC., a Delaware corporation (these two parties
collectively referred to herein as "Gilead") and EYETECH PHARMACEUTICALS, INC.,
a Delaware corporation (hereinafter "EyeTech"), to amend the Licensing
Agreement made effective as of March 31, 2000 (the "Agreement") by and among
Gilead and EyeTech, whereby Gilead licensed EyeTech to further clinically
develop and commercialize Gilead's proprietary compound NX 1838. Capitalized
terms used and not otherwise defined herein shall have the meanings given them
in the Agreement.

                                    RECITALS

     WHEREAS, the Parties desire to amend the Agreement to define the term
"Proprietary Information" which was employed but not defined in the Licensing
Agreement, and to set the term of survival for the confidentiality,
nondisclosure and nonuse obligations pertaining to such Proprietary Information.

     NOW, THEREFORE, in consideration of the foregoing and the covenants and
promises contained in this Amendment, and the Parties hereby amend the
Agreement as follows:

1. Section 1.1 is hereby amended to insert the following defined term and
definition immediately following the definition for Product Inventory:

          "Proprietary Information" shall mean, subject to Section 6.3 of the
     Agreement, any Know-How, patent applications or other confidential
     information of a Party disclosed by such Party to another Party in the
     course of negotiating or performing under this Agreement or any other
     written agreement between the Parties entered into on or prior to May 9,
     2000. Proprietary Information shall be deemed to include the terms of this
     Agreement and the terms of any other written agreement between the Parties
     entered into on or prior to May 9, 2000.

2. Section 6.3 is hereby amended to add the following new paragraph to the end
of such section:

          The obligations of confidentiality, nondisclosure and nonuse contained
     in this Section 6.3 shall survive any expiration or termination of this
     Agreement for a period of five (5) years.

3. The Agreement, as amended by this Amendment, shall remain in full force and
effect according to its terms.

4. This Amendment may be executed in any number of counterparts, each of which
shall be deemed an original, and all of which taken together shall constitute
one and the same instrument.

5. This Amendment shall be effective as of the date first written above.

     IN WITNESS WHEREOF, the parties hereto have duly executed this Amendment
effective as of the date first written above.

GILEAD SCIENCES, INC.                  EYETECH PHARMACEUTICALS, INC.

By:  /s/ Mark L. Perry                 By:  /s/ David Guyer
   ---------------------------------      ----------------------------------

Name:  Mark L. Perry                   Name:  David Guyer

Title: Senior Vice President,          Title: Chief Executive Officer
       Operations

NEXSTAR PHARMACEUTICALS, INC.

By:  /s/ Mark L. Perry
   ---------------------------------

Name:  Mark L. Perry

Title: Chief Financial Officer

<PAGE>

                   "[AMENDMENT NO. 2]" TO LICENSING AGREEMENT

     THIS AMENDMENT NO. 2 ("the Second Amendment") is entered into as of
December 4, 2001, by and between EyeTech Pharmaceuticals, Inc. a Delaware
corporation ("EyeTech") and Gilead Sciences, Inc., a Delaware corporation
("Gilead"), to amend that certain Licensing Agreement dated as of March 31,
2000, as amended by Amendment No. 1 to Licensing Agreement dated as of May 9,
2000 (the "Agreement") by and between EyeTech and Gilead (as successor in
interest to NeXstar Pharmaceuticals, Inc.). Capitalized terms used and not
otherwise defined herein shall have the meanings given them in the Agreement.

     WHEREAS, EyeTech desires to obtain access to notebooks of Gilead relating
or potentially relating to the compound NX1838;

     WHEREAS, Gilead is willing to provide such access to EyeTech personnel if
the information in such notebooks is kept confidential by EyeTech and its
personnel under the terms of the Agreement;

     WHEREAS, in support of EyeTech's activities under the Agreement, Gilead
would like to provide to EyeTech, and EyeTech would like to receive from
Gilead, certain of Gilead's inventory of VEGF aptamer and potentially a
reference standard possessed by Gilead, as determine by Gilead ("Materials").

     NOW, THEREFOR, in consideration of the foregoing and the covenants
herein, EyeTech and Gilead hereby agree, and the Agreement is hereby amended,
as follows:

1. All information learned, received, extracted or copied by EyeTech from
notebooks or other documents or records of Gilead, or excerpts thereof, that
Gilead provides or makes available to EyeTech after the date hereof shall be
deemed to be Proprietary Information of Gilead and subject to provisions in the
Agreement pertaining to Proprietary Information of Gilead.

2. Nothing in this Second Amendment shall be construed as creating any
obligation of Gilead to provide or make available to EyeTech any notebooks or
other documents or records of Gilead, or excerpts thereof, beyond any such
obligation of Gilead currently existing under the Agreement.

3. Gilead will deliver the materials to EyeTech within fifteen (15) days after
the date hereof.

4. EyeTech shall not and shall not permit any person or entity to (a) administer
any Materials to humans under any circumstances; or (b) administer any Materials
to animals except in compliance with U.S. National Institutes of Health
guidelines and all other applicable laws, rules, and regulations.

5. Nothing in this Amendment shall be construed to grant either Party any right
or license beyond those set forth in the Agreement.

6. GILEAD PROVIDES THE MATERIALS "AS IS", WITH NO WARRANTY, EXPRESS, IMPLIED OR
STATUTORY, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, TITLE,
NON-INFRINGEMENT, EXCLUSIVITY, OR FITNESS FOR A PARTICULAR PURPOSE.

7. Solely for purposes of Section 7.1(b) of the Agreement, the Materials will
deemed to included within NX1838.

8. The Agreement, as amended by this Second Amendment, shall remain in full
force and effect according to its terms.

9. This Second Amendment may be executed in any number of counterparts, each of
which shall be deemed an original, and all of which taken together shall
constitute one and the same instrument.

10. This Second Amendment shall be effective as of the date first written above.

     IN WITNESS WHEREOF, the parties hereto have duty executed this Second
Amendment effective as of the date first written above.

EYETECH PHARMACEUTICALS, INC.                GILEAD SCIENCES, INC.

By:    /s/  Harsha Murthy                    By:    /s/  Nicole Onetto
       ----------------------                       -------------------------

Name:  Harsha Murthy                         Name:  Nicole Onetto

Title: V.P. - Business Development &         Title: SVP Medical Affairs
       General Counsel

1

<PAGE>

                     AMENDMENT NO. 3 TO LICENSING AGREEMENT

         This Amendment No. 3 to Licensing Agreement (the "Third Amendment")
amends, effective August, 2002, the LICENSING AGREEMENT, itself effective
as of March 30, 2002 and previously amended first as of May 9, 2000 and second
as of December 4, 2001 (as so twice amended, the "Agreement") originally by and
among GILEAD SCIENCES, INC., a Delaware corporation with its principal office
located at 333 Lakeside Drive, Foster City, CA 94404 ("Gilead"), and its
wholly-owned subsidiary, NEXSTAR PHARMACEUTICALS, INC., a Delaware corporation,
on the one hand, and EYETECH PHARMACEUTICALS, INC., a Delaware corporation with
its principal office as of the date hereof located at 500 Seventh Avenue, 18th
Floor, New York, New York 10018 ("EyeTech"), on the other hand, and currently
between Gilead and EyeTech. All capitalized terms used herein and not otherwise
defined shall have the meanings given in the Agreement. All references to
"Sections" and "Articles" are to sections and articles of the Agreement unless
otherwise specified below.

         The Parties hereby amend the Agreement as follows:

     1.  The definition of Net Sales is deleted in its entirety and replaced
with the following:

"`Net Sales' shall mean, with respect to the Product, the gross amount billed or
invoiced by EyeTech, its Affiliates or sublicensees to Third Parties for
Products and Combination Products (defined below), less the following deductions
to the extent included in such billed or invoiced or credited amounts:

               (a)  trade, quantity and cash discounts allowed, but expressly
excluding discounts or allowances offered as part of a package of products that
includes a Product sold by EyeTech, its Affiliates or sublicensees;

               (b)  refunds, chargebacks and any other allowances which
effectively reduce the net selling price;

               (c)  actual product returns, credits and allowances allowed to
customers;

               (d)  rebates actually paid or credited to any governmental agency
(or branch thereof) or to any Third Party payor, administrator or contractee;

               (e)  discounts mandated by, or granted to meet the requirements
of, applicable state, provincial or federal law, wholesaler, including required
chargebacks and retroactive price reductions;

               (f)  transportation, freight, postage charges and other charges
such as insurance, relating thereto, in each case included as a specific line
item on an invoice to such Third Parties; and

               (g)  taxes, excises or other governmental charges upon or
measured by the production, sale, transportation, delivery or use of goods, in
each case included as a specific line item on an invoice to such Third Parties.

                                       2.
<PAGE>

If any such sales to Third Parties are made in transactions that are not at
arm's length between the buyer and the seller, then the gross amount to be
included in the calculation of Net Sales shall be the amount that would have
been invoiced had the transaction been conducted at arm's length. Such amount
that would have been invoiced shall be determined, wherever possible, by
reference to the average selling price of the relevant Product in arm's-length
transactions in the relevant country.

If EyeTech, its Affiliate or sublicensee sells a Product in unfinished form to a
Third Party for resale, then the gross amount to be included in the calculation
of Net Sales arising from such sale shall be the amount invoiced by the Third
Party upon resale, in lieu of the amount invoiced by EyeTech, its Affiliates or
sublicensee when selling the Product in unfinished form. Otherwise, where
EyeTech, its Affiliate or sublicensee sells a Product in finished form to a
Third Party that does not require a sublicense under the Licensed Patents for
further resale (a distributor) (each such Third Party hereinafter a
"Distributor"), the amount to be included in the calculation of Net Sales shall
be the price invoiced from EyeTech or its Affiliate or sublicensee to the Third
Party, not the amount invoiced by the Third Party upon resale.

If, in addition to or in lieu of a transfer price paid for quantities of Product
supplied, any Distributor provides consideration to EyeTech, its Affiliate or
sublicensee in connection with any Product or the Distributor's rights or
relationship with EyeTech, its Affiliate or sublicensee in relation thereto,
then such consideration shall be included in the calculation of Net Sales in the
calendar quarter in which it becomes due to EyeTech or its Affiliate or
sublicensee (as applicable).

Notwithstanding the foregoing, amounts received by EyeTech, or its Affiliates or
sublicensees, for the sale of Products among EyeTech and its Affiliates or
sublicensees for resale shall not be included in the computation of Net Sales
hereunder.

Net Sales shall be determined from books and records maintained in accordance
with GAAP, consistently applied throughout the organization and across all
products of the entity whose sales of Product are giving rise to Net Sales.

If any Product (i) contains or is sold with a therapeutically active ingredient
other than NX1838 (such therapeutically active ingredient an "Other Active"),
regardless of whether they are coformulated or physically packaged together, or
(ii) is sold with a mechanical or pharmacological delivery system for the
delivery of such Product (such system, a "Delivery System), (such a Product
including and together with the Other Active or Delivery System, a "Combination
Product") then Net Sales from the Combination Product shall be determined by
multiplying the Net Sales of the Combination Product (as determined without
reference to the calculations of this paragraph) by the fraction A/(A+B), where
A is the average sale price of a Product of the same formulation and dosage when
not sold as part of a Combination Product, and B is the average sale price of
the Other Active or Delivery System when sold separately, or, only if the value
of B cannot be determined, where A+B is the average sales price of the
Combination Product. If A and B can be determined, in no event will the sales
price of the Combination Product be less than the sum of A and B. If both A and
B, and A+B, cannot be determined, then C/(C+D) shall be substituted for A/(A+B)
in such calculation, where C is EyeTech's cost of goods of the Product and D is
EyeTech's cost of goods for the Other Active or Delivery System, determined in
accordance with the method of accounting normally employed by EyeTech in
computing cost of goods sold (which must be in accordance with GAAP consistently
applied throughout EyeTech), provided, however, that the minimum value of

                                       3.
<PAGE>

such fraction as used in the calculation of Net Sales shall be 0.9. All average
prices, for purposes of this paragraph, shall be determined on a
country-by-country and product-by-product basis.

For clarity and without limiting the generality of the foregoing, the inclusion
of PEG (polyethylene gylcol) in a Product, because PEG is not a therapeutically
active molecule, will not in itself be deemed to result in a Combination Product
for purposes of the foregoing paragraph."

     2.   The phrase "with a right to sublicense to its Affiliates or (subject
          to Section 2.4) to any other Person" in Section 2.1 is deleted and
          replaced with the following: "with a right (subject to Section 2.4) to
          sublicense to its Affiliates or to any other Person."

     3.   In Section 2.5, the phrase "EyeTech Know-How and EyeTech Patents" in
          the nineteenth (19th) line is deleted and replaced with the following:
          "EyeTech Rights."

     4.   The following words are included in the sentence that is the text of
          Section 2.3, at the end of the sentence: "within the scope of the
          license granted EyeTech in Section 2.1."

     5.   Section 3.3(b) is deleted in its entirety and replaced with the
          following:

     "Offset. Notwithstanding the foregoing, on a country-by-country and
     Product-by-Product basis, EyeTech may credit against Royalties otherwise
     due hereunder on Net Sales of such Product in such country [**] percent in
     any calendar quarter ([**]%) of any royalties it must pay to any Third
     Party on sales of such Product in such country in such calendar quarter:
     (1) pursuant to any licenses necessary to practice the License; or (2)
     resulting from any litigation (including settlement thereof) under Section
     6.16; provided, however, for purposes of this Section 3.3(b) that the
     applicable royalty rates used for calculation of Royalties payable to
     Gilead shall not be reduced to less than [**]percent ([**]%) of the royalty
     rate(s) otherwise applicable pursuant to Section 3.3(a)."

     6.   The following is inserted between the first and second sentences of
          Section 3.7: "EyeTech shall promptly remit any amounts so withheld to
          the appropriate governmental authority and provide Gilead with written
          evidence of such payment."

     7.   Section 4.6 is deleted in its entirety and replaced with the
          following:

     "Accrued Rights and Obligations; Survival. Termination or expiration of
     this Agreement for any reason shall be without prejudice to any rights
     which shall have accrued to the benefit of either Party prior to such
     termination or expiration, including damages arising from any breach
     hereunder. The following provisions of this Agreement shall survive any
     expiration or termination of this Agreement: Sections 2.3, 3.6, 4.2, 4.6,
     5, 6.3, 6.4, 6.5, 6.9, 6.11(a), 6.12, 6.18, 7, and 8. In addition, the
     following provisions of this Agreement shall survive the expiration of this
     Agreement to the extent that the license granted to EyeTech pursuant to
     Section 4.2 is in effect: Sections 3.4 through 3.9, 4.3, 4.5, 6.2,
     6.7(c)-(e), 6.8, 6.9, 6.11(b), 6.11(c), 6.11(d), 6.13, 6.16 and 6.17(a)."

     8.   The last sentence of Section 6.13 is deleted in its entirety and
          changed to read as follows: "Except as otherwise permitted by this
          Agreement or required by law, Gilead shall refrain from granting any
          right to any Third Party relating to NX1838, the Licensed Patents or
          the

                                       4.
<PAGE>

          Transferred Assets that would, in any manner, violate the terms of or
          conflict with the rights granted to EyeTech pursuant to this
          Agreement.

     9.   The phrase "distribution," is inserted immediately prior to
          "administration" in the second (2nd) line of Section 7.1(b)(3).

     10.  Section 8.2, "Notices" is changed to show EyeTech's address as
          follows: EyeTech Pharmaceuticals, Inc., 500 Seventh Avenue, 18th
          Floor, New York, New York 10018, Facsimile: 212-997-9251, attn: Chief
          Executive Officer.

     11.  The Agreement, as amended by this Third Amendment, remains in full
          force and effect according to its terms.

     12.  Article 18 shall apply to this Third Amendment as if set forth herein
          in its entirety.

          IN WITNESS WHEREOF, the Parties have caused this Third Amendment to be
duly executed and delivered as of the day and year first above written.

GILEAD SCIENCES, INC.                        EYETECH PHARMACEUTICALS, INC.

By: /s/Gregg Alton                           By: /s/David Guyer
   ---------------------------------------      --------------------------------

Name: Gregg Alton                               David Guyer

Title: Vice President and General Counsel       Chief Executive Officer

NEXSTAR PHARMACEUTICALS, INC.

By: ___________________________________

Name: _________________________________

Title: ________________________________

                                       5.

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