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                                                                   EXHIBIT 10.22

                             CUMMINGS PROPERTIES, LLC                  ORIGINAL
                                  STANDARD FORM
                                COMMERCIAL LEASE                  03020102-RSY-A

In consideration of the covenants herein contained, Cummings Properties, LLC,
hereinafter called LESSOR, does hereby lease to Eyetech Pharmaceuticals, Inc. (a
DE corp.), 666 Fifth Avenue, New York, NY 10103 hereinafter called LESSEE, the
following described premises, hereinafter called the leased premises:
approximately 10,752 square feet at 42 and 43 Cummings Park, Woburn, MA 01801 as
such premises are shown on Exhibit A attached hereto .

TO HAVE AND HOLD the leased premises for a term of five (5) years commencing at
noon on July 1, 2002 and ending at noon on June 30, 2007 unless sooner
terminated as herein provided. LESSOR and LESSEE now covenant and agree that the
following terms and conditions shall govern this lease during the term hereof
and for such further time as LESSEE shall hold the leased premises or any
portion thereof.

      1. RENT. LESSEE shall pay to LESSOR base rent at the rate of two hundred
three thousand seven hundred fifty (203,750) U.S. dollars per year, drawn on a
U.S. bank, payable in advance in monthly installments of $16,979.16 on the first
day in each calendar month. The first monthly payment, plus an appropriate
fraction of a monthly payment for any portion of a month at the commencement of
the lease term, shall be made upon LESSEE's execution of this lease. All
payments shall be made to LESSOR or agent at 200 West Cummings Park, Woburn,
Massachusetts 01801, or at such other place as LESSOR shall from time to time in
writing designate. If the "Cost of Living" has increased as shown by the
Consumer Price Index (Boston, Massachusetts, all items, all urban consumers),
U.S. Bureau of Labor Statistics, the amount of base rent due during each
calendar year of this lease and any extensions thereof shall be annually
adjusted in proportion to any increase in the Index. All such adjustments shall
take place with the rent due on January 1 of each year during the lease term.
The base month from which to determine the amount of each increase in the Index
shall be January 2002 , which figure shall be compared with the figure for
November 2002 , and each November thereafter to determine the percentage
increase (if any) in the base rent to be paid during the following calendar
year. In the event the Consumer Price Index as presently computed is
discontinued as a measure of "Cost of Living" changes, any adjustment shall then
be made on the basis of a comparable index then in general use.

      2. SECURITY DEPOSIT. LESSEE shall pay to LESSOR a security deposit in the
amount of fifty thousand nine hundred (50,900) U.S. dollars upon the execution
of this lease by LESSEE, which shall be held as security for LESSEE's
performance as herein provided and refunded to LESSEE without interest at the
end of this lease, subject to LESSEE's satisfactory compliance with the
conditions hereof. LESSEE may not apply the security deposit to any payment due
under the lease. In the event of any default or breach of this lease by LESSEE,
however, LESSOR may elect to apply the security deposit first to any unamortized
improvements completed for LESSEE's occupancy, then to offset any outstanding
invoice or other payment due to LESSOR, and then to outstanding rent. If all or
any portion of the security deposit is applied to cure a default or breach
during the term of the lease, LESSEE shall restore said deposit forthwith.
LESSEE's failure to remit the full security deposit or any portion thereof or to
restore said deposit when due shall constitute a substantial lease default.
Until such time as LESSEE pays the security deposit and first month's rent,
LESSOR may declare this lease null and void for failure of consideration.

      3. USE OF PREMISES. LESSEE shall use the leased premises only for the
purpose of executive and administrative offices, research and animal testing
laboratory and any other lawful uses incidental thereto.


      4. ADDITIONAL RENT. LESSEE shall pay to LESSOR as additional rent a
proportionate share (based on square footage leased by LESSEE as compared with
the total leaseable square footage of the building or buildings of which the
leased premises are a part (hereinafter called the building)) of any increase in
the real estate taxes levied against the land and building, excluding interest
or penalties due resulting from LESSOR's negligence, whether such increase is
caused by an increase in the tax rate, or the assessment on the property, or a
change in the method of determining real estate taxes. LESSEE shall make payment
within 30 days after receipt of any invoice from LESSOR, and any additional rent
shall be prorated should the lease terminate before the end of any tax year. The
base from which to determine the amount of any increase in taxes shall be the
rate and the assessment in effect as of July 1, 2002 . Notwithstanding anything
to the contrary contained in this lease, the following shall be excluded from
taxes and shall be paid solely by LESSOR: inheritance, estate, succession,
transfer, gift, franchise, or capital stock tax, or any income taxes arising out
of or related to ownership and operation of income-producing real estate, or any
excise taxes imposed upon LESSOR based upon gross or net rentals or other income
received by it; any increase in taxes and assessments resulting from LESSOR's
sale of, or other transfer of its interest in, the building; and assessments,
charges, taxes, rents fees, rates, levies, excises, license fees, permit fees,
inspection fees, or other authorization fees or charges to the extent allocable
to or caused by the development or installation of off-site improvements or
utilities (including without limitation street and intersection improvements,
roads, rights of way, lighting and signalization) necessary for the initial
development or construction of the building.

      5. UTILITIES. LESSOR shall provide equipment per LESSOR's building
standard specifications to heat the leased premises in season and to cool all
office and lab areas between May 1 and November 1. LESSEE shall pay all charges
for utilities used on the leased premises, including electricity, gas, oil,
water and sewer, and shall use whichever utility service provider LESSOR shall
designate from time to time. LESSEE shall pay the utility provider or LESSOR, as
applicable, for all such utility charges as determined by separate meters
serving the leased premises and/or as a proportionate share of the utility
charges for the building if not separately metered. LESSEE shall also pay LESSOR
a proportionate share of any other fees and charges relating in any way to
utility use at the building.

      6. COMPLIANCE WITH LAWS. LESSEE acknowledges that no trade, occupation,
activity or work shall be conducted in the leased premises or use made thereof
which may be unlawful, improper, noisy, offensive, or contrary to any applicable
statute, regulation, ordinance or bylaw. LESSEE shall keep all employees working
in the leased premises covered by Worker's Compensation Insurance and shall
obtain any licenses and permits necessary for LESSEE's use and occupancy. LESSEE
shall be responsible for causing the leased premises following delivery of
possession by LESSOR in full compliance with any applicable statute, regulation,
ordinance or bylaw, and any alterations by LESSEE allowed hereunder to be in
full compliance with any applicable statute, regulation, ordinance or bylaw.
Notwithstanding the foregoing or any other provision of this lease, however,
LESSEE shall not be responsible for compliance with any such laws, regulations,
or the like requiring (i) structural repairs or modifications or (ii)
installation of new building service equipment, such as fire detection or
suppression equipment, unless such repairs, modifications, or installments shall
(a) be due to LESSEE's particular manner of use of the leased premises or (b) be
due to the negligence or willful misconduct of LESSEE or any agent, employee, or
contractor of LESSEE.

      7. FIRE, CASUALTY, EMINENT DOMAIN. Should a substantial portion of the
leased premises, or of the property of which they are a part, be substantially
damaged by fire or other casualty, or be taken by eminent domain, LESSOR may
elect to terminate this lease. When such fire, casualty, or taking renders the
leased premises substantially unsuitable for their intended use, a proportionate
abatement of rent shall be made, and LESSEE may elect to terminate this lease
if: (a) LESSOR fails to give written notice within 30 days of intention to
restore the leased premises; or (b) LESSOR fails to restore the leased premises
to a condition substantially suitable for their intended use within 90 days of
said fire, casualty or taking. LESSOR reserves all rights for damages or injury
to the leased premises for any taking by eminent domain, except for damage to
LESSEE's property or equipment.

      8. FIRE INSURANCE. LESSEE shall not permit any use of the leased premises
which will adversely affect or make voidable any insurance on the property of
which the leased premises are a part, or on the contents of said property, or
which shall be contrary to any law, regulation or recommendation from time to
time made by the Insurance Services Office (or successor organization), state
fire prevention agency, local fire department, LESSOR's insurer, or any similar
entity. LESSEE shall on demand reimburse LESSOR and all other tenants all extra
insurance premiums caused by LESSEE's use of the leased premises. LESSEE shall
not vacate the leased premises or permit same to be unoccupied other the during
LESSEE's customary non-business days or hours, unless LESSEE continues to pay
rent and otherwise comply with its obligations under this lease.

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      9. MAINTENANCE OF PREMISES. LESSOR will be responsible for all structural
maintenance of the leased premises including, without limitation, that required
in connection with the roof, exterior walls, floor slabs, and common areas, and
for the normal daytime maintenance of all space heating and cooling equipment,
sprinklers, doors, locks, plumbing, and electrical wiring, but specifically
excluding damage caused by the careless, malicious, willful, or negligent acts
of LESSEE, its agents, employees, or invitees, chemical, water or corrosion
damage from any source except LESSOR's negligence and maintenance of any
"non-building standard" leasehold improvements, whether installed by LESSOR,
LESSEE or a prior occupant. LESSEE agrees to maintain at its expense all other
aspects of the leased premises in the same condition as they are at the
commencement of the term or as they may be put in with LESSOR's written consent
during the term of this lease, normal wear and tear and damage by fire or other
casualty only excepted, and whenever necessary, to replace light bulbs and
glass, acknowledging that the leased premises are now in good order and the
light bulbs and glass whole. LESSEE shall at all times properly control and vent
all solvents, degreasers, radioactive materials, smoke, odors, and any other
materials that may be harmful, and shall not cause the area surrounding the
leased premises or any other common area as defined below to be in anything
other than a neat and clean condition, depositing all waste in appropriate
receptacles. LESSEE shall be solely responsible for any damage to plumbing
equipment, sanitary lines, or any other portion of the building which results
from the discharge or use of any substance by LESSEE. LESSEE shall not permit
the leased premises to be overloaded, damaged, stripped or defaced, nor suffer
any waste, and will not keep animals within the leased premises. If the leased
premises include any wooden mezzanine type space, the floor capacity of such
space is suitable only for office use, light storage or assembly work. LESSEE
will protect any carpet with plastic or Masonite chair pads under any rolling
chairs. Unless heat is provided at LESSOR's expense, LESSEE shall maintain
sufficient heat to prevent freezing of pipes or other damage. Any increase in
air conditioning equipment or electrical capacity, or any installation or
maintenance of equipment which is necessitated by some specific aspect of
LESSEE's use of the leased premises, whether installed by LESSOR, LESSEE or a
prior occupant, shall be LESSEE's sole responsibility, at LESSEE's expense and
subject to LESSOR's prior written consent. All maintenance provided by LESSOR
shall be during LESSOR's normal business hours.

      10. ALTERATIONS. LESSEE shall not make structural alterations or additions
of any kind to the leased premises, but may make nonstructural alterations with
LESSOR's prior written consent, except consent shall not be required for
non-structural alterations costing no more than $5,000, provided such
alterations otherwise comply with this lease. All such allowed alterations shall
be at LESSEE's expense and shall conform with LESSOR's construction
specifications. If LESSOR or its agent provides any services or maintenance for
LESSEE in connection with such alterations or otherwise under this lease,
including any maintenance or repairs LESSEE is required but has failed to do,
LESSEE will promptly pay any just invoice. LESSEE shall not permit any
mechanics' liens, or similar liens, to remain upon the leased premises in
connection with work of any character performed or claimed to have been
performed at the direction of LESSEE and shall cause any such lien to be
released or removed forthwith without cost to LESSOR. Any alterations or
additions shall become part of the leased premises and the property of LESSOR,
except with the prior written consent of LESSOR. At the time of installation of
the improvement or addition, LESSEE may request a written determination from
LESSOR as to whether the improvement or addition must be removed at the
expiration or earlier termination of the leased term. Any alterations completed
by LESSOR or LESSEE shall be LESSOR's building standard unless noted otherwise.
LESSOR shall have the right at any time to make additions to the building,
change the arrangement of parking areas, stairs, or walkways or otherwise alter
common areas as defined below or the exterior of the building, provided such
changes do not materially interfere with LESSEE's use of the leased premises.

      11. ASSIGNMENT OR SUBLEASING. LESSEE shall not assign this lease or sublet
or allow any other entity or individual to occupy the whole or any part of the
leased premises without LESSOR's prior written consent in each and every
instance which consent shall not be unreasonably withheld. In no case may LESSEE
assign this lease or sublet the leased premises to any other current or
prospective tenant of LESSOR, or any affiliate of such current or prospective
tenant. Notwithstanding LESSOR's consent to any assignment or subleasing, LESSEE
and GUARANTOR shall remain liable to LESSOR for the payment of all rent and for
the full performance of all covenants and conditions of this lease. LESSEE shall
pay LESSOR for reasonable legal and administrative expenses incurred by LESSOR
in connection with any consent requested hereunder by LESSEE.

      12. SUBORDINATION. This lease shall be subject and subordinate to any and
all mortgages and other instruments in the nature of a mortgage, now or at any
time hereafter, and LESSEE shall, when requested, promptly execute and deliver
such written instruments as shall be necessary to show the subordination of this
lease to said mortgages or other such instruments in the nature of a mortgage.

      13. LESSOR'S ACCESS. LESSOR and its agents and designees may at any
reasonable time with reasonable notice except in the case of emergency enter to
view the leased premises; to show the leased premises to others; to make repairs
and alterations as LESSOR or its designee should elect to do for the leased
premises, the common areas, or any other portions of the building; and without
creating any obligation or liability for LESSOR, to make repairs which LESSEE is
required but has failed to do. Any such entry shall be made so as not to
unreasonably interfere with LESSEE's use of the leased premises.

      14. SNOW REMOVAL. The plowing of snow from all roadways and unobstructed
parking areas shall be at the sole expense and responsibility of LESSOR. The
control of snow and ice on all walkways, steps and loading areas serving the
leased premises and all other areas not readily accessible to plows shall be the
sole responsibility of LESSEE. Notwithstanding the foregoing, however, LESSEE
shall hold LESSOR and OWNER harmless from any and all claims by LESSEE's
employees, agents, callers or invitees for damage or personal injury resulting
in any way from snow or ice on any area serving the leased premises, except for
claims directly resulting from LESSOR's negligence.

      15. ACCESS AND PARKING. Unless otherwise provided herein, LESSEE shall
have the right without additional charge to use parking facilities provided for
the leased premises in common with others entitled to the use thereof. Said
parking areas plus any stairs, corridors, walkways, elevators or other common
areas (herein collectively called the common areas) shall in all cases be
considered a part of the leased premises when they are used by LESSEE or
LESSEE's employees, agents, callers or invitees. LESSEE will not obstruct in any
manner any portion of the building or the walkways or approaches to the
building, and will conform to all rules and regulations now or hereafter made by
LESSOR for parking, and for the care, use, or alteration of the building, its
facilities and approaches. LESSEE further warrants that LESSEE will not permit
any employee or visitor to violate this or any other covenant or obligation of
LESSEE. No unattended parking (i.e., parking where the driver of a vehicle is
not readily available at the leased premises) will be permitted between 7:00 PM
and 7:00 AM without LESSOR's prior written approval, and from November 15
through April 15 annually, such parking shall be permitted only in those areas
specifically designated for assigned overnight parking. Unregistered or disabled
vehicles, or storage trailers of any type, may not be parked at any time. LESSOR
may tow, at LESSEE's sole risk and expense, any misparked vehicle belonging to
LESSEE or LESSEE's employees, agents, callers or invitees, at any time. LESSOR
does not provide and shall not be responsible for providing any security
services.

      16. LIABILITY. LESSEE shall be solely responsible as between LESSOR and
LESSEE for deaths or personal injuries to all persons whomsoever occurring in or
on the leased premises (including any common areas that are considered part of
the leased premises under Section 15 above) from whatever cause arising, and
damage to property, including damage by fire or other casualty, to whomsoever
belonging arising out of the use, control, condition or occupation of the leased
premises by LESSEE; and LESSEE agrees to indemnify and save harmless LESSOR and
OWNER from any and all liability, including but not limited to costs, expenses,
damages, causes of action, claims, judgments and attorney's fees caused by or in
any way growing out of any matters aforesaid, except for death, personal
injuries or property damage directly resulting from the sole negligence of
LESSOR.

      17. INSURANCE. LESSEE will secure and carry at its own expense a
commercial general liability policy insuring LESSEE, LESSOR and OWNER against
any claims based on bodily injury (including death) or property damage arising
out of the condition of the leased premises (including any common areas that are
considered part of the leased premises hereunder) or their use by LESSEE,
including damage by fire or other casualty, such policy to insure LESSEE, LESSOR
and OWNER against any claim up to $1,000,000 in the case of any one accident
involving bodily injury (including death), and $1,000,000 against any claim for
damage to property. LESSOR and OWNER shall be included in each such policy as
additional insureds using ISO Form CG 20 26 11 85 or some other form approved by
LESSOR, and each such policy shall be written by or with a company or companies
satisfactory to LESSOR. Prior to occupancy, LESSEE will deliver to LESSOR
certificates and any applicable riders or endorsements showing that such
insurance is in force, and thereafter will provide renewal certificates at least
15 days prior to the expiration of any such policies. All such insurance
certificates shall provide that such policies shall not be cancelled without at
least 10 days prior written notice to each insured. In the event LESSEE fails to
provide or maintain such insurance at any time during the term of this lease,
LESSOR may elect to contract for such insurance at LESSEE's expense.

      18. SIGNS. LESSOR authorizes, and LESSEE at LESSEE's expense agrees to
erect promptly upon commencement of this lease, signage for the leased premises
in accordance with LESSOR's building standards for style, size, location, etc.
LESSEE shall obtain the prior written consent of LESSOR before erecting any sign
on the leased premises, which consent shall include approval as to size,
wording, design and location. LESSOR may at LESSEE's expense remove and dispose
of any sign not approved, erected, maintained or displayed in conformance with
this lease.


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      19. BROKERAGE. LESSEE warrants and represents to LESSOR that LESSEE has
dealt with no broker or third person with respect to this lease, except for
Dennis Finnegan, Coldwell Banker Commercial/NRT, whom LESSOR will pay a
commission in accordance with its standard fee schedule and LESSEE agrees to
indemnify LESSOR against any brokerage claims arising by virtue of this lease.
LESSOR warrants and represents to LESSEE that LESSOR has employed no exclusive
broker or agent in connection with the letting of the leased premises.

      20. DEFAULT AND ACCELERATION OF RENT. In the event that: (a) any
assignment for the benefit of creditors, trust mortgage, receivership or other
insolvency proceeding shall be made or instituted with respect to LESSEE or
LESSEE's property; (b) LESSEE shall default in the observance or performance of
all of LESSEE's covenants, agreements, or obligations hereunder, and such
default shall not be corrected within 10 days after written notice thereof; or
in the event such default cannot be cured within said 10-day period, LESSEE
shall not have commenced to cure and be diligently proceeding to cure, or if
LESSEE vacates the leased premises without continuing to pay rent and otherwise
comply with its obligations under this lease, then LESSOR shall have the right
thereafter, while such default continues and without demand or further notice,
to enter and take possession of the leased premises, to declare the term of this
lease ended, and to remove LESSEE's effects, without being guilty of any manner
of trespass or conversion, and without prejudice to any remedies which might be
otherwise used for arrears of rent or other default or breach of the lease. If
LESSEE shall default in the payment of the security deposit, rent, taxes, or
substantial invoice from LESSOR or LESSOR's agent for goods and/or services or
other sum herein specified, and such default shall continue for 10 days after
written notice thereof, and, because both parties agree that nonpayment of said
sums when due is a substantial breach of the lease, and, because the payment of
rent in monthly installments is for the sole benefit and convenience of LESSEE,
then, in addition to any other remedies, the entire balance of rent due
hereunder shall become immediately due and payable as liquidated damages.
LESSOR, without being under any obligation to do so and without thereby waiving
any default, may remedy same for the account and at the expense of LESSEE. If
LESSOR pays or incurs any obligations for the payment of money in connection
therewith, such sums paid or obligations incurred, plus interest and reasonable
costs, shall be paid to LESSOR by LESSEE as additional rent. Any sums received
by LESSOR from or on behalf of LESSEE at any time shall be applied first to any
unamortized improvements completed for LESSEE's occupancy, then to offset any
outstanding invoice or other payment enforcing any or all obligations of LESSEE
under this lease at any time provided LESSEE is in default of this lease. LESSEE
shall pay LESSOR interest at the rate of 18 percent per annum on any payment
from LESSEE to LESSOR which is past due.

      21. NOTICE. Any notice from LESSOR to LESSEE relating to the leased
premises or to the occupancy thereof shall be deemed duly served when served by
constable, or sent to the leased premises or to the last address designated by
notice in accordance with this section, by certified or registered mail, return
receipt requested, postage prepaid, or by recognized courier service with a
receipt therefor, addressed to LESSEE with copies to Hale and Dorr, 60 State
Street, Boston, MA 02109, Attn: Pamela Coravos and Eyetech Pharmaceuticals,
Inc., 666 Fifth Avenue, 35th Floor, New York, New York 10103, Attn: General
Counsel. Any notice from LESSEE to LESSOR relating to the leased premises or to
the occupancy thereof shall be deemed duly served when served by constable, or
delivered to LESSOR by certified or registered mail, return receipt requested,
postage prepaid, or by recognized courier service with a receipt therefore,
addressed to LESSOR at 200 West Cummings Park, Woburn, MA 01801 or at LESSOR's
last designated address. No oral notice or representation shall have any force
or effect. Time is of the essence in the service of any notice.

      22. OCCUPANCY. In the event that LESSEE takes possession of the leased
premises prior to the start of the lease term, LESSEE will perform and observe
all of its covenants from the date upon which it takes possession. LESSEE shall
not remove its goods or property from the leased premises other than in the
ordinary and usual course of business, without having first paid LESSOR all rent
which may become due during the entire term of this lease. LESSOR may require
LESSEE to relocate to another similar facility upon prior written notice to
LESSEE and on terms comparable to those herein. In the event that LESSEE
continues to occupy or control all or any part of the leased premises after the
termination of this lease without the written permission of LESSOR, LESSEE shall
be liable to LESSOR for any and all loss, damages or expenses incurred by
LESSOR, and all other terms of this lease shall continue to apply, except that
use and occupancy payments shall be due in full monthly installments at a rate
of 150 percent of the monthly rent due under this lease immediately prior to
termination or at LESSOR's then current published rent for the leased premises,
whichever is greater, it being understood that such extended occupancy is a
tenancy at sufferance, solely for the benefit and convenience of LESSEE and of
greater rental value. LESSEE's control or occupancy of all or any part of the
leased premises beyond noon on the last day of any monthly rental period shall
constitute LESSEE's occupancy for an extra additional month, and increased
payment as provided in this section shall be due and payable immediately in
advance. LESSOR's acceptance of any payments from LESSEE during such extended
occupancy shall not alter LESSEE's status as a tenant at sufferance.

      23. FIRE PREVENTION. LESSEE agrees to use every reasonable precaution
against fire, and agrees to provide and maintain approved, labeled fire
extinguishers, emergency lighting equipment, and exit signs following delivery
of possession by LESSOR in full compliance with any applicable statutes,
regulation, bylaws and the like and complete any other modifications within the
leased premises as required or recommended by the Insurance Services Office (or
successor organization), OSHA, the local fire department, LESSOR's insurer or
any similar entity.

      24. OUTSIDE AREA. Any goods, equipment, or things of any type or
description held or stored in any common area without LESSOR's prior written
consent shall be deemed abandoned and may be removed by LESSOR at LESSEE's
expense without notice. LESSEE shall maintain a building standard size dumpster
in a location approved by LESSOR, which dumpster shall be provided and serviced
at LESSEE's expense by whichever disposal firm LESSOR may designate from time to
time. Alternatively, if a shared dumpster or compactor is provided by LESSOR,
LESSEE shall pay the disposal firm or LESSOR, as applicable, LESSEE's
proportionate share of any costs associated therewith.

      25. ENVIRONMENT. LESSEE will so conduct and operate the leased premises as
not to interfere in any way with the use and enjoyment of other portions of the
same or neighboring buildings by others by reason of odors, smoke, exhaust,
smells, noise, pets, accumulation of garbage or trash, vermin or other pests, or
otherwise, and will at its expense employ a professional pest control service if
necessary. LESSEE agrees to maintain efficient and effective devices for
preventing damage to plumbing and heating equipment from solvents, degreasers,
cutting oils, propellants, acids, etc. which may be present at the leased
premises. No hazardous materials or wastes shall be stored, disposed of, or
allowed to remain at the leased premises at any time, except in full compliance
with any applicable statutes, regulation, bylaws and the like, and LESSEE shall
be solely responsible for any and all corrosion or other damage in any way
associated with the use, storage and/or disposal of same by LESSEE.

      26. RESPONSIBILITY. Neither LESSOR nor OWNER shall be held liable to
anyone for loss or damage caused in any way by the use, leakage, seepage or
escape of water from any source, or for the interruption or cessation of any
service rendered customarily to the leased premises or building or agreed to by
the terms of this lease, or due to any accident, the making of repairs,
alterations or improvements, labor difficulties, weather conditions, mechanical
breakdowns, trouble or scarcity in obtaining fuel, electricity, service or
supplies from the sources from which they are usually obtained for the building,
or due to any change in any utility or service provider, or any cause beyond
LESSOR's immediate control.

      27. SURRENDER. LESSEE shall at the termination of this lease remove all of
LESSEE's goods and effects from the leased premises. LESSEE shall deliver to
LESSOR the leased premises and all keys and locks thereto, all fixtures and
equipment connected therewith, and all alterations, additions and improvements
made to or upon the leased premises, whether completed by LESSEE, LESSOR or
others, including but not limited to any offices, partitions, window blinds,
floor coverings (including computer floors), plumbing and plumbing fixtures, air
conditioning equipment and ductwork of any type, exhaust fans or heaters, water
coolers, burglar alarms, telephone wiring, telephone equipment, air or gas
distribution piping, compressors, overhead cranes, hoists, trolleys or
conveyors, counters, shelving or signs attached to walls or floors, and all
electrical work, including but not limited to lighting fixtures of any type,
wiring, conduit, EMT, transformers, distribution panels, bus ducts, raceways,
outlets and disconnects, and furnishings and equipment which have been bolted,
welded, nailed, screwed, glued or otherwise attached to any wall, floor,
ceiling, roof, pavement or ground, or which have been directly wired to any
portion of the electrical system or which have been plumbed to the water supply,
drainage or venting systems serving the leased premises. LESSEE shall
[illegible] the leased premises fully sanitized from any chemicals or other
contaminants, caused by LESSEE, LESSEE's agent, employees, invitees, or
contractors, broom clean, and in the same condition as they were at the
commencement of this lease or any prior lease between the parties for the leased
premises, or as they were modified during said term with LESSOR's written
consent, reasonable wear and tear and damage by fire or other casualty only
excepted. Any of LESSEE's property that remains in the leased premises upon
termination of the lease shall be deemed abandoned and shall be disposed of as
LESSOR sees fit, with no liability to LESSEE for loss or damage thereto, and at
the sole risk of LESSEE. LESSOR may remove and store any such property at
LESSEE's expense; retain same under LESSOR's control; sell same at public or
private sale (without notice) and apply the net proceeds of such sale to the
payment of any sum due hereunder, or destroy same. In no case shall the leased
premises be deemed surrendered to LESSOR until the termination date provided
herein or such other date as may be specified in a written agreement between the
parties, notwithstanding the delivery of any keys to LESSOR.


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      28. [Illegible] (a) The invalidity or unenforceability of any provision of
this lease shall not affect or render invalid or unenforceable any other
provision hereof. (b) The obligations of this lease shall run with the land, and
this lease shall be binding upon and inure to the benefit of the parties hereto
and their respective successors and assigns, except that LESSOR and OWNER shall
be liable for obligations occurring only while lessor or owner of the leased
premises. (c) Any action or proceeding arising out of the subject matter of this
lease shall be brought by LESSEE within one year after the cause of action has
occurred and only in a court within the commonwealth of Massachusetts. (d) If
LESSOR is acting under or as agent for any trust or corporation, the obligations
of LESSOR shall be binding upon the trust or corporation, but not upon any
trustee, officer, director, shareholder, or beneficiary of the trust or
corporation individually. (e) If LESSOR is not the owner (OWNER) of the leased
premises, LESSOR represents that OWNER has agreed to be bound by the terms of
this lease unless LESSEE is in default hereof. (f) This lease is made and
delivered in the commonwealth of Massachusetts, and shall be interpreted,
construed, and enforced in accordance with the laws thereof. (g) This lease was
the result of negotiations between parties of equal bargaining strength, and
when executed by both parties shall constitute the entire agreement between the
parties, superseding all prior oral and written agreements, representations,
statements and negotiations relating in any way to the subject matter herein.
This lease may not be extended or amended except by written agreement signed by
both parties or as otherwise provided herein, and no other subsequent oral or
written representation shall have any effect hereon. (h) Notwithstanding any
other statements herein, LESSOR makes no warranty, express or implied,
concerning the suitability of the leased premises for LESSEE's intended use. (i)
LESSEE agrees that if LESSOR does not deliver possession of the leased premises
as herein provided for any reason, LESSOR shall not be liable for any damages to
LESSEE for such failure, but LESSOR agrees to use reasonable efforts to deliver
possession to LESSEE at the earliest possible date. A proportionate abatement of
rent, excluding the cost of any amortized improvements to the leased premises,
for such time as LESSEE may be deprived of possession of the leased premises,
except where a delay in delivery is caused in any way by LESSEE, shall be
LESSEE's sole remedy. (j) Neither the submission of this lease form or any
amendment hereof, nor the prospective acceptance of the security deposit and/or
rent shall constitute a reservation of or option for the leased premises, or an
offer to lease, it being expressly understood and agreed that neither this lease
nor any amendment shall bind either party in any manner whatsoever unless and
until it has been executed by both parties. (k) LESSEE shall not be entitled to
exercise any option contained herein if LESSEE is at that time in default of any
terms or conditions hereof. (l) Except as otherwise provided herein, neither
LESSOR, nor OWNER, nor LESSEE shall be liable for any special, incidental,
indirect or consequential damages, including but not limited to lost profits or
loss of business, arising out of or in any manner connected with performance or
nonperformance under this lease, even if any party has knowledge of the
possibility of such damages. (m) The headings in this lease are for convenience
only and shall not be considered part of the terms hereof. (n) No restriction,
condition or other endorsement by LESSEE on any check nor LESSOR's deposit of
any full or partial payment shall bind LESSOR in any way or limit LESSOR's
rights under this lease. (o) LESSOR, LESSEE, OWNER and GUARANTOR hereby waive
any and all rights to a jury trial in any proceeding in any way arising out of
this lease.

      30. WAIVERS, ETC. No consent or waiver, express or implied, by LESSOR to
or of any breach of any covenant, condition or duty of LESSEE shall be construed
as a consent or waiver to or of any other breach of the same or any other
covenant, condition or duty. If LESSEE is several persons, several corporations
or a partnership, LESSEE's obligations are joint or partnership and also
several. Unless repugnant to the context, "LESSOR" and "LESSEE" mean the person
or persons, natural or corporate, named above as LESSOR and as LESSEE
respectively, and their respective heirs, executors, administrators, successors
and assigns.

      32. ADDITIONAL PROVISIONS. (Continued on attached rider(s) if necessary.)

                             - See Attached Rider -


      IN WITNESS WHEREOF, LESSOR and LESSEE have hereunto set their hands and
common seals, intending to be legally bound hereby this 27th day of March, 2002.

<TABLE>
<S>                                                <C>
LESSOR: CUMMINGS PROPERTIES, LLC                   LESSEE: EYETECH PHARMACEUTICALS, INC.

By: /s/ DENNIS CLARKE                              By: /s/ DAVID R. GUYER
   ------------------------------------------          ------------------------------------
                             Duly authorized                                Duly authorized

                                                   Print name: David R. Guyer
                                                               ----------------------------
</TABLE>
                                    GUARANTY

      IN CONSIDERATION of Cummings Properties, LLC making this lease with LESSEE
at the request of the undersigned (GUARANTOR) and in reliance on this guaranty,
GUARANTOR hereby personally guarantees the prompt payment of rent by LESSEE and
the performance by LESSEE of all terms, conditions, covenants and agreements of
the lease, any amendments thereto and any extensions or assignments thereof, and
the undersigned promises to pay all expenses, including reasonable attorney's
fees, incurred by LESSOR in enforcing all obligations of LESSEE under the lease
or incurred by LESSOR in enforcing this guaranty. LESSOR's consent to any
assignments, subleases, amendments and extensions by LESSEE or to any compromise
or release of LESSEE's liability hereunder, with or without notice to the
undersigned, or LESSOR's failure to notify the undersigned of any default and/or
reinstatement of the lease by LESSEE, shall not relieve the undersigned from
liability as GUARANTOR.

      IN WITNESS WHEREOF, the undersigned GUARANTOR has hereunto set his/her/its
hand and common seal, intending to be legally bound hereby this   day of   ,   .


                               -------------------------------------------------

                               Print name:
                                          --------------------------------------
<PAGE>
                             CUMMINGS PROPERTIES, LLC             03020102-RSY-9
                                 STANDARD FORM
                                 RIDER TO LEASE

The following additional provisions are incorporated into and made a part of the
attached lease:

      A. CONFLICTS. In the event of any conflict between any provision of this
Rider to Lease and the attached lease, the provisions of this Rider shall
govern.

      D. PARKING. LESSEE shall be entitled to use, in common with others, a
proportionate share of the total number of common area parking spaces provided
for the building (based on square footage leased by LESSEE as compared with the
total leasable square footage of the building). The number of spaces used by
LESSEE's employees, agents and invitees shall not at any time exceed LESSEE's
proportionate share of the total spaces for the building. For purposes of
determining LESSEE's compliance with this paragraph at any time, the number of
spaces used by LESSEE shall be presumed to equal the number of persons who are
then present at the leased premises.

      E. RECORDING AND SECURITY. Although LESSOR may choose at any time to
record activities at the building with unmonitored remote television cameras,
LESSEE acknowledges and agrees that, as provided in Section 15 above, LESSOR is
not thereby or in any other way providing any security service for LESSEE or its
employees, agents, invitees, contractors and representatives, and that LESSOR
has made no representations whatsoever, written or oral, concerning the safety
of the leased premises or the presence, effectiveness or operability of any
security devices or security measures, or the safety or security of LESSEE, its
employees, agents, invitees, callers, contractors and representatives, or
LESSEE's property, against the criminal or wrongful acts of third parties.
Additionally, LESSEE accepts full responsibility for protecting the persons and
property of LESSEE and those of its employees, agents, invitees, callers,
contractors and representatives, and (acknowledging that security devices or
measures may fail or be thwarted by criminals, by other third parties or by
electrical or mechanical malfunction), agrees not to rely on any such devices or
measures, and to protect itself, its property, and its employees, agents,
invitees, callers, contractors and representatives as if such devices or
measures did not exist.

      G. * LESSOR, at LESSOR's cost, shall modify the leased premises according
to a mutually agreed upon plan attached hereto before or about the time LESSEE
takes possession of the leased premises.

      H. In the event that LESSOR is unable to obtain building permits for the
modifications at the leased premises for executive and administrative offices,
research and animal testing laboratory, LESSOR shall have the right, at its sole
expense, to appeal any such decision or apply for any required special permits.
If LESSOR declines to prosecute said appeal or apply for such special permits,
or if any such decision is upheld after all applicable appeals have been
exhausted, or if such special permits are denied, then LESSEE may cancel this
lease by serving LESSOR with prior written notice to that effect, LESSOR shall
return any money paid by LESSEE and LESSEE's undrawn Letter of Credit as
provided for below, and neither party shall have any further obligation to the
other. Cancellation of the lease, return of all monies paid and cancellation of
the undrawn Letter of Credit shall be LESSEE's exclusive remedies for any
failure by LESSOR to obtain any building permits or special permits, or
otherwise in connection with this paragraph.


      I. * With respect to any condition existing prior to the commencement of
LESSEE's occupancy under this lease, LESSOR shall hold LESSEE harmless from any
and all suits, judgments, or liabilities, for any "release," as defined in
Section 101(22) of the Comprehensive Environmental Response, Compensation and
Liability Act
<PAGE>
                                 RIDER TO LEASE                   03020102-RSY-9
                                   (CONTINUED)


of 1980, as amended ("CERCLA") or in Mass. G. L c. 21E, Section 2 ("c. 21E"), of
any "hazardous substance" as defined in Section 101(14) of CERCLA, any
"hazardous material" as defined in Section 2 of c. 21E or any petroleum
(including crude oil or any fraction thereof) as a result of any activity on the
property of which the leased premises are a part occurring prior to LESSEE's
occupancy and not caused in any way by LESSEE.

      J. * LESSEE shall reasonably and quietly have, hold and enjoy the leased
premises for the term hereof without hindrance or molestation from LESSOR,
provided LESSEE is not in arrears of any rent or invoice payment and is in full
compliance with all terms, conditions and obligations of this lease.

      K. * Except in the case of an emergency, LESSOR's access to the leased
premises will be at such times as will not unreasonably interfere with the
normal business operations of LESSEE.

      L. * LESSEE shall have access to the leased premises seven days per week,
24 hours per day. LESSEE acknowledges and agrees that LESSOR has no
responsibility for providing any security services for the leased premises, and
LESSEE assumes any and all risks in that regard.

      M. * With reference to Section 25 above, no hazardous materials or
hazardous wastes shall be used, processed, stored, or disposed of in any manner
or form within the leased premises or any extension thereof in violation of any
applicable local, state, or federal law, rule or regulation. LESSEE shall be
solely responsible for and shall indemnify and hold LESSOR harmless from any and
all liability, damage or personal injury associated with any use, processing,
storage, or disposal of such materials caused by LESSEE, LESSEE's agents,
employees, invitees, or contractors.

      N. * Prior to the termination date of this lease, LESSEE, at LESSEE's sole
expense, shall engage an independent and certified industrial hygienist ("the
CIH") to prepare a decontamination work plan for the leased premises in
accordance with all CIH professional standards and all applicable laws to
address all conditions arising out of LESSEE's tenancy. LESSEE shall submit said
plan to LESSOR for LESSOR's review and consent. LESSEE shall then complete all
measures specified in said plan, including testing and cleaning of all surfaces
and other building components recommended therein. The CIH shall certify that as
of the termination date of this lease, the entire leased premises and any
extension thereof used in any way by LESSEE is free from any harmful chemical,
biological or other contamination arising out of LESSEE's tenancy, in accordance
with all applicable CIH professional standards and all applicable laws. Said
certification shall confirm the clean condition of all ductwork, plumbing
fixtures, drains, tanks, mechanical systems, cabinetry, casework, all other
surfaces, and the indoor air quality at the leased premises, and shall specify
that there are no restrictions on future use and occupation by others. This
certification and any required and recommended cleaning shall be completed prior
to the termination of this lease. Time is of the essence.

      O. * LESSEE's maintenance obligations as provided in Section 9 above shall
specifically include, without limitation, monthly inspections of all acid
neutralization, pH adjustment and other wastewater treatment tanks and
equipment; drain lines into which said tanks and equipment discharge; backflow
preventers; air filters; and all other exhaust and intake fan components,
including belts. LESSEE shall be responsible for all maintenance and repairs of
said equipment, both routine and otherwise, including semiannual (or more
frequent if necessary) cleaning and replenishment of neutralizing materials in
pH adjustment tanks. LESSEE acknowledges and agrees that the plumbing,
electrical, heating and cooling systems provided and maintained by LESSOR are
intended and sized only for office use, and any maintenance or additional
equipment necessitated by LESSEE's use of and operation at the leased premises
shall be at LESSEE's sole expense. LESSEE agrees that all wastewater discharged
from the leased premises, including deionized water, shall be neutralized to a
pH of 7.0+/- and shall fully comply with all applicable state and local
statutes, codes, regulations and/or ordinances.

      P. Intentionally omitted.
<PAGE>
                                 RIDER TO LEASE                   03020102-RSY-9
                                   (CONTINUED)

      Q. * The preceding paragraph regarding LESSEE's maintenance responsibility
is a key consideration of this lease.

      R. * LESSOR consents to LESSEE's access to the roof of the building for
maintenance of HVAC equipment serving the leased premises (only). LESSEE further
agrees that no other work shall be carried on or any other equipment installed
on the roof without the prior written consent of LESSOR. LESSEE shall be fully
responsible for, and agrees to indemnify and hold LESSOR harmless from, any and
all property damage and personal injury associated in any way with the
activities of LESSEE and LESSEE's agents, employees and contractors on the roof
and/or the location, installation or maintenance of LESSEE's equipment on the
roof including, but not limited to, damage to the watertight integrity of the
roof and the roof membrane from whatever cause.

      S. LESSEE shall have the right to assign this lease to an entity in which
LESSEE owns at least a 50 percent interest, an entity which owns at least a 50
percent interest in LESSEE, an entity which is under common control with LESSEE,
or an entity which is formed as a result of a merger or consolidation involving
LESSEE, without further consent from LESSOR, provided LESSEE serves LESSOR with
prior written notice to that effect. The provisions of Section 11 shall govern
said assignment in all other respects.

      T. In the event LESSOR approves a sublease or an assignment of the lease,
LESSEE shall pay LESSOR on the first of each month during the period of the
sublease or assignment, 50 percent of any amount by which the payments due to
LESSEE under the sublease or assignment exceed the rent payment due from LESSEE
to LESSOR for that month, after deducting any brokerage commissions, legal fees
in connection with the assignment or sublease, improvement costs incurred by
LESSEE and not reimbursed in connection with the assignment or sublease, and
advertising costs. Such amount shall, however, be calculated on a proportionate
basis in the case of a sublease of only a portion of the leased premises.

      U. * This lease may be assigned to a new corporation to be formed by
LESSEE, as provided in Section 11 of this lease, without further consent from
LESSOR, provided LESSEE timely notifies LESSOR in writing to that effect and
executes LESSOR's standard lease assignment. The provisions of Section 11 shall
govern said assignment in all other respects.

      V. * LESSOR warrants that as of the date of execution of this lease, the
leased premises are not encumbered by any mortgage or instrument in the nature
of a mortgage.

      W. * LESSEE's agreement to subordinate this lease to any and all mortgages
and/or other instruments in the nature of a mortgage, now or at any time in the
future, is conditional upon the mortgagee's agreement that LESSEE's possession
will not be disturbed so long as LESSEE is not in default in the payment of rent
or other covenants or obligations hereof.

      X. * In the event that the entire balance of rent is accelerated pursuant
to Section 20 above on account of the non-payment of any sums due under this
lease, provided LESSEE then fully cures such non-payment and pays any other sums
that are then due (including LESSOR's legal fees and costs) prior to the entry
of a judgment for possession, LESSOR agrees to reinstate the lease in full and
to waive the acceleration of the rent, without waiving any rights which may
arise with respect to any subsequent default. Time is of the essence.

      Y. Notwithstanding the provisions of Section 27 above, LESSEE may remove
telephone wiring, telephone equipment and equipment supplied and installed by
LESSEE after LESSOR delivers possession only if LESSEE has satisfactorily
complied with all other conditions of this lease, repaired any and all damage
resulting from such removal, and restored the leased premises to their condition
prior to the installation of said equipment, or, to the extent the prior
condition was unfinished, supplied equipment or finishes comparable to finished
conditions elsewhere in the leased premises. LESSEE must complete all such
removal, repair, restoration and other work prior to the termination date of
this lease. Time is of the essence.
<PAGE>
                                 RIDER TO LEASE                   03020102-RSY-9
                                   (CONTINUED)

      Z. * To the extent that compensation is unavailable under LESSEE's
business interruption or other insurance coverage, LESSEE shall receive a
proportionate abatement of rent in the event that the leased premises are
rendered substantially unusable for the purposes set forth in Section 3 for at
least 10 business days as a result of any of the conditions set forth in Section
26 above. This paragraph shall not apply, however, in the case of any
interruption caused in any way by LESSEE or its employees or agents.

      AA. * LESSOR agrees to maintain casualty insurance in a commercially
reasonable amount for the building of which the leased premises are a part.

      BB. Provided that LESSEE and its employees, agents and contractors do not
interfere with LESSOR's work in the leased premises, LESSOR shall allow LESSEE
access to the leased premises to install cabling prior to the completion of
LESSOR's work. Prior to LESSEE's entry into the leased premises as permitted
hereunder, LESSEE shall submit a schedule to LESSOR (and LESSOR'S contractor, if
so requested by LESSOR), for their reasonable approval, which schedule shall
detail the timing and purpose of LESSEE's entry. LESSEE shall hold LESSOR
harmless for any claims arising from said access.

      CC. LESSOR shall be deemed to be in default of this lease if LESSOR fails
to make any payments to LESSEE required under this lease and such failure
continues for 10 days after written notice from LESSEE to LESSOR, or if LESSOR
shall be in default in the prompt and full performance of any other of its
promises, covenants or agreements contained in this lease and such default in
performance continues for more than 30 days after written notice thereof from
LESSEE to LESSOR specifying the particulars of such default or breach of
performance; provided, however, that if the default complained of, other than
for the payment of monies, is of such a nature that the same cannot be rectified
or cured within such 30 day period, then such default shall be deemed to be
rectified or cured if LESSOR, within such 30 day period, shall have commenced
such cure and shall continue thereafter with due diligence to cause such cure to
be completed. Upon any default of this lease by LESSOR, LESSEE shall be entitled
to take reasonable steps to cure the default itself, and upon representation of
all supporting invoices paid to third parties, LESSOR shall pay LESSEE the
reasonable cost thereof.

      DD. LESSOR represents and warrants that OWNER is the sole and exclusive
owner of the leased premises, holding good and clear record and marketable title
thereto, free from encumbrances, except for encumbrances that will not adversely
affect LESSEE'S use and enjoyment of the leased premises for the purposes
permitted hereunder, that the leased premises are subject to no mortgages, and
that no other party has any possessory right to the leased premises or, to
LESSOR'S knowledge, has claimed the same.


LESSOR: CUMMINGS PROPERTIES, LLC         LESSEE: EYETECH PHARMACEUTICALS, INC.


By: /s/ DENNIS CLARKE                    By: /s/ DAVID R. GUYER
   ---------------------------------        ------------------------------------
                    Duly authorized                              Duly authorized

Date: 3-27-02                            Print Name: David R. Guyer
     -------------------------------                 ---------------------------
                                                                           01/01
<PAGE>
                            CUMMINGS PROPERTIES, LLC
                                  STANDARD FORM

                                                                  03020105-RSY-J

                             AMENDMENT TO LEASE # 1

      In connection with a lease currently in effect between the parties at 42
and 43 Cummings Park, Woburn, Massachusetts, on July 1, 2002 and terminating
June 30, 2007, and in consideration of the mutual benefits to be derived
herefrom, Cummings Properties, LLC, LESSOR, and Eyetech Pharmaceuticals, Inc.,
LESSEE, hereby agree, effective upon full execution, to amend said lease as
follows: *commencing

1.    Base rent is hereby changed to three hundred twenty nine thousand and
      twenty nine (329,029) dollars per year or $27,419.08 per month.

3.    Upon execution of this amendment, the security deposit shall be Increased
      by $58,350 from $50,900 to a new total of $109,250. LESSEE shall pay this
      increase upon LESSEE's execution of this amendment.

4.    LESSOR, at a cost included in the base rent above, and at an additional
      charge to LESSEE of $149,191, to be paid upon LESSEE's execution of this
      amendment, shall complete alterations and improvements within the leased
      premises in accordance with the mutually agreed upon amendment plan and
      specifications attached hereto as Exhibit A ("LESSOR's work"). LESSOR
      shall use reasonable efforts to substantially complete, except for
      punchlist items and LESSEE delays as described below, LESSOR'S work within
      60 days after full execution of the lease and this amendment; payment in
      full of the first month's rent, the $109,250 security deposit and the
      $149,191 charge for LESSOR's work; LESSOR's receipt of the Letter of
      Credit described in Section 8 below; LESSEE's approval of the attached
      plan and specifications; and LESSOR's receipt of any required building
      permits (the "completion date"). LESSOR agrees to submit its application
      for a building permit within 10 business days after full execution of this
      amendment, approval of the attached plan and specifications and payment of
      all amounts listed in the previous sentence.

5.    If for any reason other than delay requested or caused by LESSEE (which
      shall include without limitation any additions and/or changes requested by
      LESSEE to the scope of LESSOR'S work, any delay in LESSEE providing
      information to LESSOR for any permits or plans, and any interference by
      LESSEE or LESSEE's contractor with LESSOR's work) LESSOR does not
      substantially complete, except for punchlist items, the leased premises by
      the completion date, then LESSEE shall be entitled to an abatement of rent
      on a per diem basis from the completion date until LESSOR substantially
      completes its work. There shall be no rent abatement, however, for the
      total length of any delays caused by LESSEE.

6.    The term "substantially complete" shall mean that LESSOR's work has been
      completed in accordance with the attached plan and specifications and the
      equipment installed by LESSOR is functioning and in good working order,
      subject only to punchlist items which do not materially interfere with
      LESSEE's ability to open and conduct business or which do not materially
      detract from the appearance of the leased premises.

7.    LESSOR agrees that all LESSOR's work shall be completed in a good and
      workerlike manner.

      In addition to the $109,250 cash security deposit provided in Section 3
      above, LESSEE shall provide LESSOR with an Irrevocable Letter of Credit
      negotiable on sight in the amount of $175,400 as security for LESSEE's
      obligations under the lease, provided said Letter of Credit is issued
      by______________; provides for payment to LESSOR immediately and on sight
      upon LESSOR's delivery to the bank of a statement that the drawing
      represents amounts due to LESSOR from LESSEE under the lease or is
      otherwise permitted under the lease; terminates no earlier than 60 days
      after the termination of the lease; and is otherwise in a form acceptable
      to counsel for LESSOR. In addition, LESSOR shall be entitled to draw on
      said Letter of Credit and hold the proceeds as a cash security deposit in
      the event LESSOR feels insecure about the continuing solvency of the
      issuing bank. LESSOR agrees to give LESSEE written notice of its
      insecurity about the issuing bank and its intent to draw the Letter of
      Credit, and the opportunity for LESSEE to substitute a Letter of Credit
      from a different bank, if LESSOR believes in its sole judgment, that there
      is sufficient time for notice and/or substitution. In the event LESSOR
      draws on the Letter of Credit, LESSOR will promptly notify LESSEE of the
      rationale for said draw, and LESSEE may substitute a new Letter of Credit
      that complies with this section. LESSEE shall pay LESSOR for legal and
      administrative expenses incurred by LESSOR in connection with this Letter
      of Credit, to the extent LESSOR exercises reasonable judgment.

9.    Provided LESSEE is not then in default of the lease or in arrears of any
      rent or invoice payment, LESSEE may amend the Letter of Credit by reducing
      it to the following amounts: $140,320 effective July 1, 2003; $105,240
      effective July 1, 2004; $70,160 effective July 1, 2005; and $35,080
      effective July 1, 2006. LESSEE shall be responsible for any bank charges
      associated with any amendments to the Letter of Credit.

10.   The parties acknowledge and agree that, as of the execution of the lease,
      not all of the perimeter walls of the leased premises have been built.
      Accordingly, after completion of the modifications provided for herein,
      LESSOR shall carefully measure the entire leased premises, and if the size
      does not equal the total number of square feet set forth in the initial
      paragraph of the lease, LESSOR shall notify LESSEE in writing of the
      actual revised square footage and the corresponding increase or decrease
      in rent, based on the same rate per square foot used in the lease, and
      said actual square footage and adjusted rent shall be substituted for the
      figures in the lease.

          This amendment shall not bind either party in any manner until it has
been executed by both parties. All other terms, conditions and covenants of the
present lease shall continue to apply, and to the extent any inconsistency
exists between this amendment and the lease, including any prior amendments, the
conditions herein shall control and supersede any earlier provisions.

          In Witness Whereof, LESSOR and LESSEE have hereunto set their hands
and common seals this 27th day of March, 2002.

LESSOR: CUMMINGS PROPERTIES, LLC       LESSEE: EYETECH PHARMACEUTICALS, INC.

/s/ DENNIS CLARKE                      By: /s/ DAVID R. GUYER
---------------------------------          -----------------------------------
                  Duly Authorized                              Duly Authorized

                                       Print Name: David R. Guyer
                                                   ---------------------------