Document:

<PAGE>

                                                                    EXHIBIT 10.4

                                 LEASE AGREEMENT
                            Dated as of June 4, 1999

                                     between

                          ARE-100 PHILIPS PARKWAY, LLC,
                a Delaware limited liability company, as LANDLORD

                                       and

                          MEMORY PHARMACEUTICALS CORP.,
                        a Delaware corporation, as TENANT

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<S>                                                                        <C>
1.   Lease of Premises ...............................................      1
2.   Delivery; Acceptance of Premises; Commencement Date .............      1
3.   Rent ............................................................      1
4.   Additional TI Allowance .........................................      2
5.   Base Rent Adjustments ...........................................      2
6.   Operating Expenses Payments .....................................      3
7.   Security Deposit ................................................      4
8.   Use .............................................................      5
9.   Holding Over ....................................................      5
10.  Taxes ...........................................................      6
11.  Parking .........................................................      6
12.  Utilities, Services .............................................      6
13.  Alterations and Tenant's Property ...............................      7
14.  Landlord's Repairs ..............................................      7
15.  Tenant's Repairs ................................................      8
16.  Mechanic's Liens ................................................      8
17.  Indemnification .................................................      8
18.  Insurance .......................................................      9
19.  Restoration .....................................................     10
20.  Condemnation ....................................................     10
21.  Events of Default ...............................................     11
22.  Landlord's Remedies .............................................     12
23.  Assignment and Subletting .......................................     14
24.  Estoppel Certificates ...........................................     15
25.  Quiet Enjoyment .................................................     15
26.  Prorations ......................................................     15
27.  Rules and Regulations ...........................................     15
28.  Subordination ...................................................     15
29.  Surrender .......................................................     16
30.  Waiver of Jury Trial ............................................     16
31.  Environmental Requirements ......................................     16
32.  Tenant's Remedies/Limitation of Liability .......................     18
33.  Inspection and Access ...........................................     19
34.  Security ........................................................     19
35.  Force Majeure ...................................................     19
36   Limitation on Landlord's Liability ..............................     19
37.  Brokers, Entire Agreement, Amendment ............................     19
38.  Severability ....................................................     20
39.  Landlord's Lien/Security Interest ...............................     20
40.  Signs; Exterior Appearance ......................................     20
41.  Miscellaneous ...................................................     20
42.  Expansion Space and Renewal Terms. ..............................     21
</TABLE>

EXHIBIT A - DESCRIPTION OF PREMISES       EXHIBIT B - DESCRIPTION OF PROJECT
EXHIBIT C - WORK LETTER                   EXHIBIT D - ACTUAL COMMENCEMENT DATE
EXHIBIT E - RULES AND REGULATIONS         EXHIBIT F - TENANT'S PROPERTY
EXHIBIT G - ESTOPPEL CERTIFICATE          EXHIBIT H - SUBORDINATION AGREEMENT

<PAGE>

                                 LEASE AGREEMENT

         THIS LEASE AGREEMENT ("LEASE") is made this fourth day of June, 1999,
between ARE-100 PHILIPS PARKWAY, LLC, a Delaware limited liability company
("LANDLORD"), and MEMORY PHARMACEUTICALS CORP., a Delaware corporation
("TENANT").

                                   BASIC LEASE PROVISIONS

ADDRESS:                     100 Philips Parkway, Montvale, New Jersey

PREMISES:                    That portion of the Project, containing
                             approximately 30,000 rentable square feet, as
                             determined by Landlord, shown hatched on Exhibit A.

BASE RENT:                   $13.00 per rentable square foot per year, subject
                             to adjustment as described in Sections 4 and 5

RENT ADJUSTMENT PERCENTAGE:  3.0%              TENANT'S SHARE: 43.2%

RENTABLE AREA OF PREMISES:   32,000 sq. ft.    RENTABLE AREA OF PROJECT: 74,000
                                                 sq. ft.

COMMENCEMENT DATE:           The date hereof   SECURITY DEPOSIT: $300,000

TERM:                        120 months from the first day of the month
                             following the month in which the Rent Commencement
                             Date occurs

PERMITTED USE:               Research and development laboratory and related
                             uses, including, but not limited to, a chemistry
                             laboratory, a biological laboratory and an animal
                             vivarium

TENANT'S BROKER:             Insignia/ESG Jackson Cross

ADDRESS FOR RENT PAYMENT:                   LANDLORD'S NOTICE ADDRESS:
135 N. Los Robles Avenue, Suite 250         135 N. Los Robles Avenue, Suite 250
Pasadena, CA 91101                          Pasadena, CA 91101
Attention: Accounts Receivable              Attention: General Counsel

TENANT'S NOTICE ADDRESS:
3960 Broadway
New York, NY 10032

WITH A COPY TO:
Lewis Geffen, Esq.
Mintz, Levin Cohn Ferris Glovsky and Popeo PC
One Financial Center
Boston, MA 02111

                                    AGREEMENT

         1.       LEASE OF PREMISES. Upon and subject to all of the terms and
conditions hereof, Landlord hereby leases the Premises to Tenant and Tenant
hereby leases the Premises from Landlord, effective as of the date hereof. The
real property on which the building in which the Premises are located, together
with all improvements thereon and appurtenances thereto are collectively
referred to herein as the "PROJECT" and described on Exhibit B, and the portions
of the Project which are for the non-exclusive use of tenants of the Project are
collectively referred to herein at the "COMMON AREAS." Landlord reserves the
right to modify Common Areas, provided that such modifications do not materially
adversely affect Tenant's use of the Premises.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 1]

<PAGE>

         2.       DELIVERY; ACCEPTANCE OF PREMISES; COMMENCEMENT DATE. Landlord
shall use reasonable efforts to deliver the Premises to Tenant on or before July
1, 1999 (the "TARGET DELIVERY DATE"), with Landlord's Work, if any, sufficiently
completed to permit Tenant to commence its work under the Work Letter without
unreasonable cost or delay ("DELIVERY" or "DELIVER"). If Landlord fails to
Deliver the Premises, Landlord shall not be liable to Tenant for any loss or
damage resulting therefrom, and this Lease shall not be void or voidable except
as provided herein. If Landlord does not Deliver the Premises within 3 months of
the Target Delivery Date for any reason other than Force Majeure Delay or Tenant
Caused Delay, this Lease shall be voidable by Landlord or Tenant by written
notice to the other, and if voided by either: (a) the Security Deposit shall be
returned to Tenant, and (b) neither Landlord nor Tenant shall have any further
rights, duties or obligations under this Lease, except with respect to
provisions which expressly survive termination of this Lease. If neither party
elects to void this Lease within 5 business days of the lapse of such 3 month
period, such right to void this Lease shall be waived. The actual size of the
Premises and, if required, the Project shall be measured upon Delivery of the
Premises to Tenant, or at such later time as Landlord and Tenant shall agree, in
accordance with the 1996 Standard Method of Measuring Floor Area in Office
Buildings as adopted by the Building Owners and Managers Association (ANSI/BOMA
Z65.1-1996). The Rent payable hereunder and Tenant's Share shall be adjusted, if
required, on the basis of such measurement.

         The "RENT COMMENCEMENT DATE" shall be earliest of: (i) the date
Tenant's Work for Phase I is Substantially Complete, and (ii) May 1, 2000. On
the Rent Commencement Date, Tenant shall pay Base Rent for the entire Premises.
Such Rent shall be calculated for Phase I of the Premises on the basis of the
actual TI Allowance provided by Landlord to Tenant for Phase I as set forth in
Section 4(a) below, and shall be calculated at $10.00 per rentable square foot
for any portion of the Premises not included in Phase I. When Tenant's Work for
Phase II is complete, the Rent for the balance of the Premises shall be adjusted
as set forth in Section 4(a) below on the basis of the actual TI Allowance
provided by Landlord to Tenant for Phase II. Upon request of Landlord, Tenant
shall execute and deliver a written acknowledgment of the Rent Commencement Date
and the expiration date of the Term when such are established and shall attach
the acknowledgment to this Lease as part of Exhibit D; provided, however,
Tenant's failure to execute and deliver such acknowledgment shall not affect
Landlord's rights hereunder.

         Except as set forth in the Work Letter, Tenant shall accept the
Premises in their condition as of the date the Premises are Delivered, subject
to all applicable laws, ordinances, regulations, covenants and restrictions.
Neither Landlord nor any agent of Landlord has made any representation or
warranty with respect to the condition of any or all of the Premises (other than
Landlord's Work, if any) or the Project, and/or the suitability of the Premises
for the conduct of Tenant's business, and Tenant waives any implied warranty
that the Premises are suitable for Tenant's intended purposes. Except as set
forth in the Work Letter, if applicable: (i) Landlord have no obligation for
any defects in the Premises; and (ii) Tenant's taking possession of the Premises
shall be conclusive evidence that Tenant accepts the Premises and that the
Premises were in good condition at the time possession was taken. Any occupancy
of the Premises by Tenant before the Rent Commencement Date (other than for the
purpose of constructing Tenant's Work, as defined in the Work Letter) shall be
subject to all of the terms and conditions of this Lease, including the
obligation to pay Rent.

         As used herein, the terms "FORCE MAJEURE DELAY," "PHASE I," "PHASE II,"
"TENANT CAUSED DELAYS," "TENANT'S WORK," and "SUBSTANTIALLY COMPLETE" shall have
the meanings set forth for such terms in the Work Letter.

         3.       RENT.

         (a)      BASE RENT. The first month's Base Rent and the Security
Deposit shall be due and payable on the date hereof. Tenant shall pay to
Landlord in advance, without demand, deduction or set-off, monthly installments
of Base Rent on or before the first day of each calendar month during the Term
hereof. Payments of Base Rent for any fractional calendar month shall be
prorated. All payments required to be made by Tenant to Landlord hereunder shall
be payable at the address Landlord specifies from time-to-time for payment of
Rent. The obligation of Tenant to pay Base Rent and other sums to Landlord and
the obligations of Landlord under this Lease are independent obligations. Tenant
shall have no right at any time to abate, reduce, or set-off any Rent due
hereunder except for any abatement as may be expressly provided in this Lease.
Tenant

              [100 Philips Parkway/Memory Pharmaceuticals- Page 2]

<PAGE>

shall pay Base Rent and Additional Rent for the Office Space commencing upon
Tenant's occupancy thereof for the conduct of Tenant's business.

         (b)      ADDITIONAL RENT. In addition to Base Rent, Tenant agrees to
pay to Landlord as additional rent ("ADDITIONAL RENT"): (i) Tenant's Share of
"Operating Expenses," and (ii) any and all other amounts Tenant assumes or
agrees to pay under the provisions of this Lease, including, without limitation,
any and all other sums that may become due by reason of any default of Tenant or
failure to comply with the agreements, terms, covenants and conditions of this
Lease to be performed by Tenant, after any applicable notice and cure period.

         (c)      RENT. Base Rent and Additional Rent shall together be
denominated "RENT". Except as expressly provided in Section 19 hereof, Rent
shall be paid to Landlord, without abatement, deduction, or offset, in lawful
money of the United States of America, at the office of Landlord for payment of
Rent set forth above, or to such other person or at such other place as Landlord
may from time designate in writing. If the Term commences or ends on a day other
than the first day of a calendar month, then the Rent for such fraction of a
month shall be prorated and paid on the basis of a 30 day month.

         4.       ADDITIONAL TI ALLOWANCE.

         (a)      INCREASED TI ALLOWANCE. In addition to the TI Allowance
described in Exhibit C, Tenant shall have the right, upon written notice to
Landlord and provided that no Default, or event which with the giving of notice
or the passage of time, or both, would constitute an Default, has occurred and
is continuing, to increase the amount of the TI Allowance in the increments set
forth below up to a maximum increase of $180 per square foot of Rentable Area of
the Premises, not to exceed a total TI Allowance of $4,700,000 for the entire
Premises and not to exceed a TI Allowance of $3,500,000 for Phase I of the
Premises. If Tenant elects to increase the TI Allowance pursuant to this Section
4, Base Rent shall be adjusted for Phase I and for Phase II. as follows:

<TABLE>
<CAPTION>
TI Allowance           Increase in Base Rent          Initial Base Rent
-----------------------------------------------------------------------
<S>                    <C>                            <C>
  $  20.00                     $0.00                      $13.00/RSF
  $  35.00                     $1.30                      $14.30/RSF
  $  45.00                     $1.30                      $15.60/RSF
  $  55.00                     $1.30                      $16.90/RSF
  $  65.00                     $1.30                      $18.20/RSF
  $  75.00                     $1.30                      $19.50/RSF
  $  85.00                     $1.30                      $20.80/RSF
  $  95.00                     $1.30                      $22.10/RSF
  $ 105.00                     $1.30                      $23.40/RSF
  $ 115.00                     $1.30                      $24.70/RSF
  $ 125.00                     $1.40                      $26.10/RSF
  $ 135.00                     $1.40                      $27.50/RSF
  $ 145.00                     $1.40                      $28.90/RSF
  $ 155.00                     $1.40                      $30.30/RSF
  $ 165.00                     $1.40                      $31.70/RSF
  $ 175.00                     $1.40                      $33.10/RSF
</TABLE>

              [100 Philips Parkway/Memory Pharmaceuticals- Page 3]

<PAGE>

<TABLE>
<S>                           <C>                         <C>
$185.00                       $1.40                       $34.50/RSF
$195.00                       $1.40                       $35.90/RSF
$200.00                       $0.70                       $36.60/RSF
</TABLE>

         (b)      PAYMENT. Base Rent, as increased pursuant to Section 4(a)
above, shall be paid as described in Section 3 and shall be adjusted as
described in Section 5.

         5.       BASE RENT ADJUSTMENTS. Base Rent shall be increased on the
second annual anniversary of the first day of the first full month during the
Term of this Lease, and on each annual anniversary of such date thereafter, by
multiplying the Base Rent payable immediately before such adjustment by the Rent
Adjustment Percentage and adding the resulting amount to the Base Rent payable
immediately before such adjustment. Base Rent, as so adjusted, shall thereafter
be due as provided herein. Base Rent adjustments for any fractional calendar
month shall be prorated.

         6.       OPERATING EXPENSES PAYMENTS. Landlord shall deliver to Tenant
a written estimate of Operating Expenses for each calendar year (the "ANNUAL
ESTIMATE"), which may be revised by Landlord from time to time during such
calendar year. During each month of the Term, on the same date that Base Rent is
due, Tenant shall pay Landlord an amount equal to 1/12 of the annual cost, as
reasonably estimated by Landlord from time to time, of Tenant's Share of
Operating Expenses for the Project. Payments for any fractional calendar month
shall be prorated. The term "OPERATING EXPENSES" means all costs and expenses of
any kind or description whatsoever incurred or accrued by Landlord with respect
to the Project (including Taxes, reasonable reserves consistent with good
business practice for future repairs and replacements, capital expenditures
amortized over the lesser of 7 years and the useful life of such capital items
and the costs of Landlord's third party property manager or, if there is no
third party property manager administration rent in the amount of 2.5% of Base
Rent) excluding only:

         (a)      the original construction costs of the Project and renovation
prior to the date of the Lease;

         (b)      renovating, painting, redecorating or other work, which
Landlord performs for specific tenants within their premises;

         (c)      capital expenditures for expansion of the Project or for the
remodeling or refurbishment of the Project to a materially higher standard than
existed on the date of this Lease (including, without limitation, any amounts
expended by Landlord pursuant to the Work Letter).

         (e)      interest and amortization of funds borrowed by Landlord,
whether secured or unsecured;

         (f)      depreciation of the Project (except for capital improvements
the cost of which are specifically includable in Operating Expenses);

         (g)      advertising, legal and space planning expenses and leasing
commissions incurred in procuring tenants for the Project;

         (h)      salaries, wages or other compensation paid to officers and
employees of Landlord who are not assigned to the operation; management
maintenance or repair of the Project;

         (j)      costs of utilities outside normal business hours sold to
tenants of the Project;

         (k)      any expenses otherwise includable within Operating Expenses to
the extent reimbursed by persons other than tenants of the Project under leases
for space in the Project;

         (l)      legal expenses incurred in the negotiation or enforcement of
leases;

         (n)      costs relating to maintaining Landlord's existence, either as
a corporation, partnership, or other entity;

              [100 Philips Parkway/Memory Pharmaceuticals- Page 4]

<PAGE>

         (o)      cost (including attorneys' fees and costs of settlement,
judgments and payments in lieu thereof) arising from claims, disputes or
potential disputes pertaining to Landlord and/or the Project;

         (p)      costs incurred by Landlord due to the violation by Landlord or
any tenant of the terms and conditions of any lease of space in the Project;

         (q)      tax penalties incurred as a result of Landlord's negligence,
inability or unwillingness to make payment and/or to file any tax or
informational returns when due;

         (r)      costs incurred in connection with environmental clean up,
response action, or remediation on, in or under or about the Project, to the
extent related to known conditions existing in, on or under the Project on or
before the date hereof as disclosed by that certain Phase I Environmental Site
Assessment of 100 Philips Parkway, Montvale, New Jersey, dated October 21, 1998,
prepared by Dames & Moore, including without limitation any such costs incurred
in connection with the sewage holding tank disclosed therein;

         (s)      overhead and profit increment paid to the Landlord or to
subsidiaries or affiliates of Landlord for goods and/or services in or to the
Project to the extent the same exceeds the costs of such goods and/or services
rendered by unaffiliated third parties on competitive basis;

         (t)      costs arising from Landlord's charitable or political
contributions;

         (u)      costs incurred in the sale or refinancing of the Project; and

         (v)      net income, franchise, capital stock, estate or inheritance
taxes.

         Within 90 days after the end of each calendar year (or such longer
period as may be reasonably required), Landlord shall furnish to Tenant a
statement (an "ANNUAL STATEMENT") showing in reasonable detail: (a) the total
and Tenant's Share of actual Operating Expenses for the previous calendar year,
and (b) the total of Tenant's payments in respect of Operating Expenses for such
year. If Tenant's Share of actual Operating Expenses for such year exceeds
Tenant's payments of Operating Expenses for such year, the excess shall be due
and payable by Tenant as Rent no more than 30 days after delivery to Tenant of
such Annual Statement. If Tenant's payments of Operating Expenses for such year
exceed Tenant's Share of actual Operating Expenses for such year Landlord shall
pay the excess to Tenant within 30 days after delivery of such Annual Statement.

         The Annual Statement shall be final and binding upon Tenant unless
Tenant, within 90 days after Tenant's receipt thereof, shall contest any item
therein by giving written notice to Landlord, specifying each item contested and
the reason therefor. If, during such 90 day period, Tenant reasonably and in
good faith questions or contests the correctness of Landlord's statement of
Tenant's Share of Operating Expenses, Landlord will provide Tenant with access
to Landlord's books and records and such information as Landlord reasonably
determines to be responsive to Tenant's questions. If after Tenant's review of
such information, Landlord and Tenant cannot agree upon the amount of Tenant's
Share of Operating Expenses, then Tenant shall have the right to have an
independent public accounting firm selected from among the 6 largest in the
United States, hired by Tenant (at Tenant's sole cost and expense) and approved
by Landlord (which approval shall not be unreasonably withheld or delayed),
audit and/or review such Landlord's books and records for the year in question
(the "INDEPENDENT REVIEW"). The results of any such Independent Review shall be
binding on Landlord and Tenant. If the Independent Review shows that Tenant's
pro rata share of the Operating Expenses actually paid by Tenant for the
calendar year in question exceeded Tenant's obligations for such calendar year,
Landlord shall at Landlord's option either (i) credit the excess amount to the
next succeeding installments of estimated Operating Expenses or (ii) pay the
excess to Tenant within 30 days after delivery of such statement, except that
after expiration of, or termination of the Term, Landlord shall pay the excess
to Tenant after deducting all other amounts due Landlord. If the Independent
Review shows that Tenant's payments of Tenant's Share of Operating Expenses for
such calendar year were less than Tenant's obligation for the calendar year,
Tenant shall pay the deficiency to the Landlord within 30 days after delivery of
such statement. If the Independent Review shows that Tenant has overpaid
Tenant's pro rata share of Operating Expenses by more than 5% then Landlord
shall reimburse Tenant for all costs incurred by Tenant for the Independent
Review. Operating Expenses for the calendar years in which Tenant's obligation
to share

              [100 Philips Parkway/Memory Pharmaceuticals - Page 5]

<PAGE>

therein begins and ends shall be prorated. Notwithstanding anything set forth
herein to the contrary, if the Project is not at least 95% occupied on average
during any year of the Term, Tenant's Share of Operating Expenses for such year
shall be computed as though the Project had been 95% occupied on average during
such year.

         "TENANT'S SHARE" shall be the percentage set forth in the Basic Lease
Provisions as Tenant's Share as reasonably adjusted by Landlord in the future
for changes in the physical size of the Premises or the Project. Landlord may
equitably increase Tenant's Share for any item of expense or cost reimbursable
by Tenant that relates to a repair, replacement, or service that benefits only
the Premises or only a portion of the Project that includes the Premises or that
varies with occupancy or use.

         7.       SECURITY DEPOSIT. Tenant shall deposit with Landlord on the
date of this Lease security (the "SECURITY DEPOSIT") for the performance of all
of its obligations in the amount set forth in the Basic Lease Provisions, which
security shall be in the form of either cash or an unconditional and irrevocable
letter of credit (the "LETTER OF CREDIT"): (i) in form and substance
satisfactory to Landlord, (ii) naming Landlord as beneficiary, (iii) expressly
allowing Landlord to draw upon it at any time from time to time by delivering to
the issuer notice that Landlord is entitled to draw thereunder, (iv) drawable on
an FDIC-insured financial institution satisfactory to Landlord, and (v)
redeemable in the state of Landlord's choice. If Tenant does not provide
Landlord with a substitute Letter of Credit complying with all of the
requirements hereof at least ten (10) days before the stated expiration date of
the current Letter of Credit Landlord shall have the right to draw upon the
current Letter of Credit and hold the funds drawn as the Security Deposit. The
Security Deposit shall be held by Landlord as security for the performance of
Tenant's obligations under this Lease. If Tenant defaults under this Lease,
Landlord may use any part of the Security Deposit to pay or perform any
obligation of Tenant under this Lease, or to compensate Landlord for any loss or
damage resulting from any default, without prejudice to any other remedy
provided herein or provided by law. Upon bankruptcy or other debtor-creditor
proceedings against Tenant, the Security Deposit shall be deemed to be applied
first to the payment of Rent and other charges due Landlord for periods prior to
the filing of such proceedings. To the extent any portion of the Security
Deposit is used, Tenant shall, within five (5) days after demand from Landlord,
reinstate the Security Deposit to its full amount. If Tenant shall perform all
of its obligations under this Lease and return the Premises to Landlord at the
end of the Term, Landlord shall return any remaining Security Deposit or Letter
of Credit to Tenant. Following an initial public offering of the capital stock
of Tenant, Landlord will reevaluate the Security Deposit required hereunder to
determine, in its sole good faith discretion, whether any reduction in the
amount of the Security Deposit held hereunder is appropriate.

         If Landlord transfers its interest in the Project or this Lease,
Landlord shall either (a) transfer any Letter of Credit or Security Deposit then
held by Landlord to a person or entity assuming Landlord's obligations under
this Section 7, or (b) return to Tenant any Letter of Credit or Security Deposit
then held by Landlord and remaining after the deductions permitted herein. Upon
such transfer to such transferee or the return of the Letter of Credit and/or
Security Deposit to Tenant, Landlord shall have no further obligation with
respect to the Letter of Credit and/or Security Deposit, and Tenant's right
to the return of the Letter of Credit and/or Security Deposit shall apply solely
against Landlord's transferee. The Security Deposit is not an advance rental
deposit or a measure of Landlord's damages in case of Tenant's default.
Landlord's obligation respecting the Security Deposit is that of a debtor, not a
trustee and no interest shall accrue thereon.

         8.       USE. The Premises shall be used solely for the Permitted Use
set forth in the Basic Lease Provisions and for lawful purposes incidental
thereto, all in compliance with all laws, orders, judgments, ordinances,
regulations, codes, directives, permits, licenses, covenants and restrictions
now or hereafter applicable to the Premises, and the use and occupancy thereof
(collectively, "LEGAL REQUIREMENTS"). Tenant shall, upon 5 days' written notice
from Landlord, discontinue any use of the Premises which is declared by any
governmental authority having jurisdiction to be a violation of any Legal
Requirement. Tenant will not use or permit the Premises to be used for any
purpose or in any manner that would void Tenant's or Landlord's insurance,
increase the insurance risk, or cause the disallowance of any sprinkler or other
credits. Tenant shall reimburse Landlord promptly upon demand for any additional
premium charged for any such policy by reason of Tenant's failure to comply with
the provisions of this Section. Tenant will use the Premises in a careful, safe
and proper manner and will not commit waste, overload the floor or structure of
the Premises, subject the Premises to use that would damage the Premises or
obstruct or interfere with the rights of Landlord or other tenants or occupants
of the Project, including conduct or give notice of any auction,

              [100 Philips Parkway/Memory Pharmaceuticals- Page 6]

<PAGE>

liquidation, or going out of business sale on the Premises, or use or allow the
Premises to be used for any unlawful purpose. Tenant shall cause any office
equipment or machinery to be installed in the Premises so as to reasonably
prevent sounds or vibrations therefrom from extending into Common Areas, or
other space in the Project. Tenant shall not place any equipment weighing 1,000
pounds or more in or upon the Premises or transport or move such items through
the Common Areas of the Project or in the Project elevators without the prior
written consent of Landlord. Except as may be provided under the Work Letter,
Tenant shall not, without the prior written consent of Landlord, use the
Premises in any manner which will require ventilation, air exchange, heating,
gas, steam, electricity or water beyond the existing capacity of the Project as
proportionately allocated to the Premises based upon Tenant's Share as usually
furnished for the Permitted Use.

         Tenant, at its sole expense, shall make any alterations or
modifications, to the interior or the exterior of the Premises or the Project,
that are required by Legal Requirements (including, without limitation,
compliance of the Premises with the Americans With Disabilities Act, 42 U.S.C.
Section 12101, et seq. (together with regulations promulgated pursuant thereto,
"ADA")) related to Tenant's use or occupancy of the Premises. Notwithstanding
any other provision herein to the contrary, Tenant shall be responsible for any
and all demands, claims, liabilities, losses, costs, expenses, actions, causes
of action, damages or judgments, and all reasonable expenses incurred in
investigating or resisting the same (including, without limitation, reasonable
attorneys' fees, charges and disbursements and costs of suit) (collectively,
"CLAIMS") arising out of or in connection with Legal Requirements and Tenant
shall indemnify, defend, hold and save Landlord harmless from and against any
and all Claims arising out of or in connection with any failure of the Premises
to comply with any Legal Requirement. Landlord shall be responsible for the
compliance of the common areas of the Project with the ADA as of the
Commencement Date, and Landlord shall indemnify, defend and hold Tenant harmless
from and against any loss, cost, liability or expense (including reasonable
attorneys fees and disbursements) arising out of any such failure to comply with
the ADA.

         9.       HOLDING OVER. If, with Landlord's express written consent,
Tenant retains possession of the Premises after the termination of the Term,
unless otherwise agreed in writing, such possession shall be subject to
immediate termination by Landlord at any time, and all of the other terms and
provisions of this Lease (including, without limitation, the adjustment of Base
Rent pursuant to Section 5 hereof) shall remain in full force and effect
(excluding any expansion or renewal option or other similar right or option)
during such holdover period, and in such case Tenant shall continue to pay Base
Rent in the amount payable upon the date of the expiration or earlier
termination of this Lease or such other amount as Landlord may indicate, in
Landlord's sole and absolute discretion, in such written consent. All other
payments shall continue under the terms of this Lease. If Tenant remains in
possession of the Premises after the expiration or earlier termination of the
Term without the express written consent of Landlord, Tenant shall become a
tenant at sufferance upon the terms of this Lease except that the monthly rental
shall be equal to 150% of the Rent in effect during the last 30 days of the
Term. In addition, Tenant shall be responsible for all damages suffered by
Landlord resulting from or occasioned by Tenant's holding over. No holding over
by Tenant, whether with or without consent of Landlord, shall operate to extend
this Lease except as otherwise expressly provided, and this Section 9 shall not
be construed as consent for Tenant to retain possession of the Premises.
Acceptance by Landlord of Rent after the Term Expiration Date or earlier
termination of this Lease shall not result in a renewal or reinstatement of this
Lease.

         10.      TAXES. Landlord shall pay, as part of Operating Expenses, all
taxes, levies, assessments and governmental charges of any kind (collectively
referred to as "TAXES") imposed by any federal, state, regional, municipal,
local or other governmental authority or agency, including, without limitation,
quasi-public agencies (collectively, "GOVERNMENTAL AUTHORITY") during the Term,
including, without limitation all Taxes: (i) imposed on or measured by or based,
in whole or in part, on rent payable to Landlord under this Lease and/or from
the rental by Landlord of the Project or any portion thereof, or (ii) based on
the square footage, assessed value or other measure or evaluation of any kind of
the Premises or the Project, or (iii) assessed or imposed by or on the operation
or maintenance of any portion of the Premises or the Project, including parking,
or (iv) assessed or imposed by, or at the direction of, or resulting from
statutes or regulations, or interpretations thereof, promulgated by, any
Governmental Authority, or (v) imposed as a license or other fee on Landlord's
business of leasing space in the Project. Landlord may contest by appropriate
legal proceedings the amount, validity, or application of any Taxes or liens
securing Taxes. Taxes shall not include any net income,

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<PAGE>

franchise, capital stock, estate or inheritance taxes imposed on Landlord unless
such net income taxes are in substitution for any Taxes payable hereunder. If
any such Tax is levied or assessed directly against Tenant, then Tenant shall be
responsible for and shall pay the same at such times and in such manner as the
taxing authority shall require. Tenant shall pay, prior to delinquency, any and
all Taxes levied or assessed against any personal property or trade fixtures
placed by Tenant in the Premises, whether levied or assessed against Landlord or
Tenant. If any Taxes on Tenant's personal property or trade fixtures are levied
against Landlord or Landlord's property, or if the assessed valuation of the
Project is increased by a value attributable to improvements in or alterations
to the Premises, whether owned by Landlord or Tenant and whether or not affixed
to the real property so as to become a part thereof, higher than the base
valuation on which Landlord from time-to-time allocates Taxes to all tenants in
the Project, Landlord shall have the right, but not the obligation, to pay such
Taxes. Landlord's reasonable determination of any excess assessed valuation
shall be binding and conclusive, absent manifest error. The amount of any such
payment by Landlord shall constitute Additional Rent due from Tenant to Landlord
immediately upon demand.

         11.      PARKING. Subject to any applicable local governmental
restrictions or requirements, Tenant shall have a revocable license to park in
common with other tenants of the Project 90 cars in those areas designated for
non-reserved parking subject to Landlord's rules and regulations and shall
further have 8 designated visitor parking spaces which shall be reserved for the
use of Tenant's visitors. Landlord may allocate parking spaces among Tenant and
other tenants in the Project if Landlord determines that such parking facilities
are becoming crowded. Landlord shall not be responsible for enforcing Tenant's
parking rights against any third parties, including other tenants of the
Project.

         12.      UTILITIES, SERVICES. Landlord shall provide, subject to the
terms of this Section 12, water, electricity, heat, light, power, telephone,
sewer, and other utilities (including gas and fire sprinklers to the extent the
Project is plumbed for such services), refuse and trash collection and
janitorial services (collectively, "UTILITIES"). Landlord shall pay, as
Operating Expenses or subject to Tenant's reimbursement obligation below, for
all Utilities used on the Premises, all maintenance charges for Utilities, and
any storm sewer charges or other similar charges for Utilities imposed by any
governmental entity or Utility provider, and any taxes, penalties, surcharges or
similar charges thereon. Landlord may cause, at Tenant's expense, any Utilities
to be separately metered or charged directly to Tenant by the provider. Tenant
shall pay directly to the Utility provider, prior to delinquency, any separately
metered Utilities and services which may be furnished to Tenant or the Premises
during the Term. Tenant shall pay, as part of Operating Expenses, its share of
all charges for jointly metered Utilities based upon consumption, as reasonably
determined by Landlord. Landlord shall not be liable for, nor shall any eviction
of Tenant result from, the failure to make available or furnish any such utility
or service, whether or not such failure is caused by accident, breakage, failure
to repair or repairs, force majeure, or by any other cause, excluding the gross
negligence or willful misconduct of Landlord or its Related Parties. In the
event of such failure, Tenant shall not be entitled to any abatement or
reduction of Rent, nor be relieved from the operation of any covenant or
agreement of this Lease; provided, however, that if such failure is due to the
gross negligence or willful misconduct of Landlord, its employees, agents or
contractors and such interruption renders a substantial portion of the Premises
untenantable for their intended purposes for more than 5 continuous business
days, then, as Tenant's sole and exclusive remedy for such failure, Tenant's
obligation to pay Rent shall abate for the period of time that the Premises
remains substantially untenantable. Tenant agrees to limit use of water and
sewer in the Common Areas to normal restroom use.

         13.      ALTERATIONS AND TRADE FIXTURES. Any alterations, additions, or
improvements made to the Premises by or on behalf of Tenant commencing after
completion of Tenant's and Landlord's initial build-out of the Premises,
including additional locks or bolts of any kind or nature upon any doors or
windows in the Premises ("ALTERATIONS"), but excluding from Alterations (i)
installation, removal or realignment of furniture systems (other than removal
of furniture systems owned or paid for by Landlord) and (ii) during any 12 month
period during the Term, up to $25,000 of cosmetic modifications to the Premises,
in either case of (i) or (ii) not involving any modifications to the structure
or connections (other then by ordinary plugs or jacks) to building systems.
Alterations shall be subject to Landlord's prior written consent, which shall be
given or withheld within 10 business days following any request therefor and
which shall not be unreasonably withheld or conditioned. If Landlord approves
any Alterations, Landlord may impose such conditions on Tenant in connection
with the commencement, performance and completion of such Alterations as
Landlord may deem

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<PAGE>

appropriate in Landlord's reasonable discretion. Any request for approval shall
be in writing, delivered not less than 15 business days in advance of any
proposed construction, and accompanied by plans, specifications, bid proposals,
work contracts and such other information concerning the nature and cost of the
alterations as may be reasonably requested by Landlord, including the identities
and mailing addresses of all persons performing work or supplying materials.
Landlord's right to review plans and specifications and to monitor construction
shall be solely for its own benefit, and Landlord shall have no duty to see that
such plans and specifications or construction comply with applicable Legal
Requirements. Tenant shall cause, at its expense, all Alterations to comply with
insurance requirements and with Legal Requirements and shall implement at its
sole cost and expense any alteration or modification required by Legal
Requirements as a result of any Alterations. Tenant shall pay to Landlord, as
Additional Rent, within 10 days of demand an amount equal to 5% of all charges
incurred by Tenant or its contractors or agents in connection with any
Alteration to cover Landlord's overhead and expenses for plan review,
coordination, scheduling and supervision. Before beginning any Alteration,
Landlord may post on and about the Premises notices of non-responsibility
pursuant to applicable law. Tenant shall reimburse Landlord for, and indemnify
and hold Landlord harmless from, any extra expense incurred by Landlord by
reason of faulty work done by Tenant or its contractors, delays caused by such
work, or inadequate cleanup.

         Tenant shall furnish security or make other arrangements reasonably
satisfactory to Landlord to assure payment for the completion of all work free
and clear of liens, and shall provide certificates of insurance for worker's
compensation and other coverage in amounts and from an insurance company
satisfactory to Landlord protecting Landlord against liability for personal
injury or property damage during construction. Upon completion of any
Alterations, Tenant shall deliver to Landlord: (i) sworn statements setting
forth the names of all contractors and subcontractors who did the work and final
lien waivers from all such contractors and subcontractors; and (ii) as built
plans for any such Alteration.

         Other than (i) the items, if any, listed on EXHIBIT F attached hereto,
(ii) any items agreed by Landlord in writing to be included on EXHIBIT F in the
future, and (iii) any trade fixtures, machinery, equipment and other personal
property not paid for out of the TI Fund which may be removed without material
damage to the Premises, which damage shall be repaired (including capping or
terminating utility hookups behind walls) by Tenant during the Term
(collectively, "TENANT'S PROPERTY"), all property of any kind paid for with the
TI Fund, Alterations, real property fixtures, built-in machinery and equipment,
built-in laboratory casework and cabinets and other similar additions and
improvements built into the Premises so as to become an integral part of the
Premises, such as fume hoods which penetrate the roof or plenum area, built-in
cold rooms, built-in warm rooms, walk-in cold rooms, walk-in warm rooms,
deionized water system, chillers, built-in plumbing, electrical and mechanical
equipment and systems, and any power generator and transfer switch
(collectively, "INSTALLATIONS") shall be and shall remain the property of
Landlord during the Term and following the expiration or earlier termination of
the Term, shall not be removed by Tenant at any time during the Term and shall
remain upon and be surrendered with the Premises as a part thereof following the
expiration or earlier termination of this Lease; provided, however, that
Landlord may at the time its approval of such Installation is requested may
elect to cause Tenant to remove such Installation upon the expiration or earlier
termination of this Lease. If Landlord elects at the time of approval of an
Installation to require such removal, Tenant shall remove such Installation upon
the expiration or earlier termination of this Lease and restore any damage
caused by or occasioned as a result of such removal. During any such restoration
period, Tenant shall pay Rent to Landlord as provided herein as if said space
were otherwise occupied by Tenant. In addition, Tenant shall, when removing any
of Tenant's Property which was plumbed, wired or otherwise connected to any of
the building systems, cap off all such connections behind the walls of the
Premises and shall repair any holes.

         14.      LANDLORD'S REPAIRS. Landlord, as an Operating Expense (except
as expressly provided for in Section 6), shall maintain all of the structural,
exterior, parking and other Common Areas of the Project, including HVAC,
plumbing, fire sprinklers, elevators and all other building systems serving the
Premises and other portions of the Project ("BUILDING SYSTEMS"), in good repair,
reasonable wear and tear and damages caused by Tenant, its agents, servants,
employees invitees and contractors excluded. Uninsured losses and damages caused
by Tenant, its agents, servants, employees, invitees and contractors shall be
repaired by Landlord at Tenant's sole cost and expense. Landlord reserves the
right to stop Building System services when necessary: (i) by reason of accident
or emergency, or (ii) for planned repairs, alterations or improvements, which
are, in the judgment of Landlord, desirable or necessary to be made, until said
repairs,

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<PAGE>

alterations or improvements shall have been completed. Landlord shall have no
responsibility or liability for failure to supply Building System services
during any such period of interruption; provided, however, that Landlord shall
give Tenant 48 hours advance notice for any for routine maintenance, repairs,
alterations or improvements and 72 hours advance notice of any planned stoppage
of Building System services, except, in either case, for emergencies. Tenant
shall promptly give Landlord written notice of any repair required by Landlord
pursuant to this Section 14, after which Landlord shall have a reasonable
opportunity to effect such repair. Landlord shall not be liable for any failure
to make any repairs or to perform any maintenance unless Landlord shall fail to
diligently pursue such repairs or maintenance for an unreasonable time after
Tenant's written notice of the need for such repairs or maintenance. Tenant
waives its rights under any state or local law, to terminate this Lease or to
make such repairs at Landlord's expense and agrees that the parties' respective
rights with respect to such matters shall be solely as set forth herein. Repairs
required as the result of fire, earthquake, flood, vandalism, war, or similar
cause of damage or destruction, shall be controlled by Section 19.

         15.      TENANT'S REPAIRS. Subject to Section 14 hereof, Tenant, at its
expense, shall repair, replace and maintain in good condition all portions of
the Premises, ordinary wear and tear excepted, including, without limitation,
entries, doors, ceilings, interior windows, interior walls, and the interior
side of demising walls. Such repair and replacements may include capital
expenditures and repairs whose benefit may extend beyond the Term. Should Tenant
fail to make any such repair or replacement or fail to maintain the Premises
Landlord shall give Tenant notice of such failure. If Tenant fails to commence
cure of such default within 10 days of Landlord's notice, and thereafter
diligently prosecute such cure to completion, Landlord may perform such work and
shall be reimbursed by Tenant within 10 days after demand therefor; provided,
however, that if such default by Tenant creates or could create an emergency,
Landlord may immediately commence cure of such default and shall thereafter be
entitled to recover the costs of such cure from Tenant. Subject to Sections 17
and 18, Tenant shall bear the full cost of any repair or replacement to any part
of the Building that results from damage caused by Tenant, its agents,
contractors, or invitees and any repair that benefits only the Premises.

         16.      MECHANIC'S LIENS. Tenant shall discharge, by bond or
otherwise, any mechanic's lien filed against the Premises or against the Project
for work claimed to have been done for, or materials claimed to have been
furnished to, Tenant within 10 days after the filing thereof, at Tenant's sole
cost and shall otherwise keep the Premises and the Project free from any liens
arising out of work performed, materials furnished or obligations incurred by
Tenant. Should Tenant fail to discharge any lien described herein, Landlord
shall have the right, but not the obligation, to pay such claim or post a bond
or otherwise provide security to eliminate the lien as a claim against title to
the project and the cost thereof shall be immediately due from Tenant as
additional Rent. If Tenant shall lease or finance the acquisition of any Tenant
Property, office equipment, furnishings, or other personal property utilized by
Tenant in the operation of Tenant's business, Tenant warrants that any Uniform
Commercial Code Financing Statement executed by Tenant will upon its face or by
exhibit thereto indicate that such Financing Statement is applicable only to
Tenant Property located within the Premises. In no event shall the address of
the Project be furnished on the statement without qualifying language as to
applicability of the lien only to removable personal property, located in an
identified suite held by Tenant.

         17.      INDEMNIFICATION. Tenant hereby indemnifies and agrees to
defend, save and hold Landlord harmless from and against any and all Claims for
injury or death to persons or damage to property occurring within or about the
Premises, arising directly or indirectly out of use or occupancy of the Premises
or a breach or default by Tenant in the performance of any of its obligations
hereunder, unless caused solely by the gross negligence or willful misconduct of
Landlord or its Related Parties. Landlord shall not be liable to Tenant for, and
Tenant assumes all risk of damage to, personal property (including, without
limitation, loss of records kept within the Premises unless caused by the gross
negligence or willful misconduct of Landlord or its Related Parties). Tenant
further waives any and all Claims for injury to Tenant's business or loss of
income relating to any such damage or destruction of personal property
(including, without limitation, any loss of records). Landlord shall not be
liable for any damages arising from any act, omission or neglect of any tenant
in the Project or of any other third party. Landlord hereby indemnifies and
agrees to defend, save and hold Tenant harmless from and against any and all
Claims for injury or death to persons or damage to property (subject

              [100 Philips Parkway/Memory Pharmaceuticals- Page 10]

<PAGE>

to Section 36 hereof) occurring within or about the Premises, arising directly
or indirectly out of the gross negligence or willful misconduct of Landlord or
its Related Parties.

         18.      INSURANCE. Landlord shall maintain all insurance against any
peril generally included within the classification "Fire and Extended Coverage,"
sprinkler damage (if applicable), vandalism and malicious mischief covering the
full replacement cost of the Project (including the Tenant Improvements
installed pursuant to the Work Letter) or such lesser coverage amount as
Landlord may elect provided such coverage amount is not less than 90% of such
full replacement cost  Landlord shall further carry public liability insurance
with a single loss limit of not less than $5,000,000 for death or bodily injury,
or property damage with respect to the Project. Landlord may, but is not
obligated to, maintain such other insurance and additional coverages as it may
deem necessary, including, but not limited to, flood, environmental hazard and
earthquake, loss or failure of building equipment, rental loss during the period
of repair or rebuild, workmen's compensation insurance and fidelity bonds for
employees employed to perform services and insurance for any improvements
installed by Tenant or which are in addition to the standard improvements
customarily furnished by Landlord without regard to whether or not such are made
a part of the Project. All such insurance shall be included as part of the
Operating Expenses. The Project may be included in a blanket policy (in which
case the cost of such insurance allocable to the Project will be determined by
Landlord based upon the insurer's cost calculations). Tenant shall also
reimburse Landlord for any increased premiums or additional insurance which
Landlord reasonably deems necessary as a result of Tenant's use of the Premises.

         Tenant, at its expense, shall maintain during the Term: all risk
property insurance covering the full replacement cost of all property and
improvements installed or placed in the Premises by Tenant at Tenant's expense;
worker's compensation insurance with no less than the minimum limits required by
law; employer's liability insurance with such limits as required by law; and
comprehensive public liability insurance, with a minimum limit of not less than
$5,000,000 per occurrence for death or bodily injury and not less than
$1,000,000 for property damage with respect to the Premises. Landlord may from
time to time require reasonable increases in any such limits. The comprehensive
public liability insurance policies shall name Landlord, its officers, directors
and employees (collectively, "RELATED PARTIES") and Landlord's managers, agents,
invitees and contractors, as additional insureds; insure on an occurrence and
not a claims-made basis; be issued by insurance companies which have a rating of
not less than policyholder rating of A and financial category rating of at least
Class XII in "Best's Insurance Guide"; shall not be cancelable unless 30 days
prior written notice shall have been given to Landlord from the insuror; contain
a hostile fire endorsement and a contractual liability endorsement; and provide
primary coverage to Landlord (any policy issued to Landlord providing duplicate
or similar coverage shall be deemed excess over Tenant's policies). Such
policies or certificates thereof shall be delivered to Landlord by Tenant upon
commencement of the Term and upon each renewal of said insurance. Tenant's
policy may be a "blanket policy" which specifically provides that the amount of
insurance shall not be prejudiced by other losses covered by the policy. Tenant
shall, at least 20 days prior to the expiration of such policies, furnish
Landlord with renewals or binders. Tenant agrees that if Tenant does not take
out and maintain such insurance, Landlord may (but shall not be required to)
procure said insurance on Tenant's behalf and at its cost to be paid as
additional Rent.

         In each instance where insurance is to name Landlord as additional
insured, Tenant shall upon written request of Landlord also designate and
furnish certificates so evidencing Landlord as additional insured to: (i) any
lender of Landlord holding a security interest in the Project or any portion
thereof, (ii) the landlord under any lease wherein Landlord is tenant of the
real property whereupon the building in which the Premises are located if the
interest of Landlord is or shall become that of a tenant under a ground lease
rather than that of a fee owner, and/or (iii) any management company retained by
Landlord to manage the Project.

         The property insurance obtained by Landlord and Tenant shall include a
waiver of subrogation by the insurers and all rights based upon an assignment
from its insured, against Landlord or Tenant, and their respective Related
Parties, in connection with any loss or damage thereby insured against. Neither
party nor its respective Related Parties shall be liable to the other for loss
or damage caused by any risk insured against under property insurance required
to be maintained hereunder, and each party waives any claims against the other
party, and its respective Related Parties for such loss or damage. The failure
of a party to insure its property shall not void this waiver. Landlord and its
respective Related Parties shall not be liable for, and Tenant hereby waives all
claims against such parties for, business interruption and losses occasioned
thereby

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<PAGE>

sustained by Tenant or any person claiming through Tenant resulting from any
accident or occurrence in or upon the Premises or the Project from any cause
whatsoever, including without limitation, damage caused in whole or in part,
directly or indirectly, by the negligence of Landlord or its respective Related
Parties. If the foregoing waivers shall contravene any law with respect to
exculpatory agreements, the liability of Landlord or Tenant shall be deemed not
released but shall be secondary to the other's insurer.

         Landlord may require insurance policy limits to be raised to conform
with requirements of Landlord's lender and/or to bring coverage limits to levels
then being required of new tenants within the Project.

         19.      RESTORATION. If at any time during the Term the Project or the
Premises are damaged by a fire or other insured casualty, Landlord shall notify
Tenant within 30 days after discovery of such damage as to the amount of time
Landlord reasonably estimates it will take to restore the Project or the
Premises, as applicable. If the restoration time is estimated by Landlord to
exceed 6 months, Landlord, in such notice, or Tenant, by written notice
delivered to Landlord within 10 days of receipt of Landlord's estimate of the
time required to restore the Premises, may elect to terminate this Lease as of
the date that is 75 days after the date of discovery of such damage or
destruction. Unless Landlord or Tenant elects to terminate this Lease, Landlord
shall, subject to receipt of sufficient insurance proceeds, promptly restore the
Premises (including the Tenant Improvements installed pursuant to the Work
Letter but excluding Tenant's Property), subject to delays arising from the
collection of insurance proceeds, from Force Majeure events or as needed to
obtain any required licenses, clearances or other authorizations of any kind
required to enter into and restore the Premises issued by any governmental or
quasi-governmental agency having jurisdiction over the use, storage, release or
removal of Hazardous Materials in, on or about the Premises (collectively
referred to herein as "HAZARDOUS MATERIALS CLEARANCES"); provided, however, that
if repair or restoration of the Premises is not Substantially Complete as of the
end of 8 months from the date of damage or destruction despite Landlord's
diligent efforts to restore the Premises, Landlord may, in its sole and absolute
discretion, elect not to proceed with such repair and restoration, in which
event Landlord shall be relieved of its obligations to make such repairs or
restoration and this Lease shall terminate as of the date that is 75 days after
the later of: (i) such damage or destruction, or (ii) the date all required
Hazardous Materials Clearances are obtained.

         Unless this Lease is terminated as provided above, Tenant at Tenant's
expense shall promptly perform, subject to delays arising from the collection of
insurance proceeds, from Force Majeure events or to obtain Hazardous Material
Clearances, all repairs or restoration not required to be done by Landlord and
shall promptly re-enter the Premises and commence doing business in accordance
with this Lease. Notwithstanding the foregoing, Landlord may terminate this
Lease if the Premises are damaged during the last two years of the Term and
Landlord reasonably estimates that it will take more than 3 months to repair
such damage, or if insurance proceeds are not available for such restoration.
Rent shall be abated from the date all required Hazardous Material Clearances
are obtained until the Premises are repaired and restored, in the proportion
which the area of the Premises, if any, which is not usable by Tenant bears to
the total area of the Premises, unless Landlord provides Tenant with other space
during the period of repair that is suitable, in Tenant's reasonable opinion,
for the temporary conduct of Tenant's business. Such abatement shall be the sole
remedy of Tenant, and except as provided herein, Tenant waives any right to
terminate the Lease by reason of damage or casualty loss.

         The provisions of this Lease, including this Section 19, constitute an
express agreement between Landlord and Tenant with respect to any and all damage
to, or destruction of, all or any part of the Premises, or any other portion of
the Project, and any statute or regulation which is now or may hereafter be in
effect, shall have no application to this Lease or any damage or destruction to
all or any part of the Premises or any other portion of the Project, the parties
hereto expressly agreeing this Section 19 sets forth their entire understanding
and agreement with respect to such matters.

         20.      CONDEMNATION. If any part of the Premises or the Project is
taken for any public or quasi-public use under governmental law, ordinance, or
regulation, or by right of eminent domain, or by private purchase in lieu
thereof (a "TAKING" or "TAKEN"), and the Taking would in Landlord's reasonable
judgment either prevent or materially interfere with Tenant's use of the
Premises or materially interfere with or impair Landlord's ownership or
operation of the Project, then upon written notice by Landlord this Lease shall
terminate and Rent shall be apportioned as of said date. If part of the Premises
shall be Taken, and this

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<PAGE>

Lease is not terminated as provided above, Landlord shall promptly restore the
Premises and the Project as nearly as is commercially reasonable under the
circumstances to their condition prior to such partial taking and the Rent
payable hereunder during the unexpired Term shall be reduced to such extent as
may be fair and reasonable under the circumstances. Upon any such Taking,
Landlord shall be entitled to receive the entire price or award from any such
Taking without any payment to Tenant, and Tenant hereby assigns to Landlord
Tenant's interest, if any, in such award. Tenant shall have the right, to the
extent that same shall not diminish Landlord's award, to make a separate claim
against the condemning authority (but not Landlord) for such compensation as may
be separately awarded or recoverable by Tenant for moving expenses and damage to
Tenant's Tenant's Property, if a separate award for such items is made to
Tenant. Tenant and Landlord hereby waive any and all rights they might otherwise
have pursuant to any provision of state law to terminate this Lease upon a
partial Taking of the Premises or the Project.

         21.      EVENTS OF DEFAULT. Each of the following events shall be a
default ("DEFAULT") by Tenant under this Lease:

         (a)      PAYMENT OF RENT DEFAULTS. Tenant shall fail to pay any
installment of Rent when due; provided, however, that Landlord, not more than
once in any 12 month period, will give Tenant notice of such default in the
payment of Rent and Tenant shall have 5 days in which to make such payment after
which period Tenant shall be in Default hereunder. Tenant agrees that such
notice shall be in lieu of and not in addition to any notice required by law.

         (b)      OTHER PAYMENT DEFAULTS. Tenant shall fail to pay any other
amount due hereunder within 5 days of Landlord's notice under this Section 21(b)
demanding such payment, which notice shall be in lieu of, and not in addition
to, any other notice required by law.

         (c)      INSURANCE. Any insurance required to be maintained by Tenant
pursuant to this Lease shall be canceled or terminated or shall expire or shall
be reduced or materially changed, or Landlord shall receive a notice of
nonrenewal of any such insurance and Tenant shall fail to obtain replacement
insurance at least 20 days before the expiration of the current coverage.

         (d)      ABANDONMENT. Tenant shall abandon the Premises.

         (e)      IMPROPER TRANSFER. Tenant shall assign, sublease or otherwise
transfer or attempt to transfer all or any portion of Tenant's interest in this
Lease or the Premises except as expressly permitted herein, or Tenant's interest
in this Lease shall be attached, executed upon, or otherwise judicially seized
and such action is not released within 90 days of the action.

         (f)      LIENS. Tenant shall fail to discharge or otherwise obtain the
release of any lien placed upon the Premises in violation of this Lease within
10 days after any such lien is filed against the Premises.

         (g)      INSOLVENCY EVENTS. Tenant or any guarantor or surety of
Tenant's obligations hereunder shall: (A) make a general assignment for the
benefit of creditors; (B) commence any case, proceeding or other action seeking
to have an order for relief entered on its behalf as a debtor or to adjudicate
it a bankrupt or insolvent, or seeking reorganization, arrangement, adjustment,
liquidation, dissolution or composition of it or its debts or seeking
appointment of a receiver, trustee, custodian or other similar official for it
or for all or of any substantial part of its property (collectively a
"PROCEEDING FOR RELIEF"); (C) become the subject of any Proceeding for Relief
which is not dismissed within 90 days of its filing or entry; or (D) die or
suffer a legal disability (if Tenant, guarantor, or surety is an individual) or
be dissolved or otherwise fail to maintain its legal existence (if Tenant,
guarantor or surety is a corporation, partnership or other entity).

         (h)      ESTOPPEL CERTIFICATE OR SUBORDINATION AGREEMENT. Tenant fails
to execute any document required from Tenant under Section 24 or 28 within 5
days after a second notice requesting such document.

         (i)      OTHER DEFAULTS. Tenant shall fail to comply with any provision
of this Lease other than those specifically referred to in this Section 21, and
except as otherwise expressly provided herein, such failure shall continue for a
period of 10 days after written notice thereof from Landlord to Tenant.

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Any notice given under Section 21(e), (g) or (h) hereof, shall: (i) specify the
alleged default, (ii) demand that Tenant cure such default,(iii) be in lieu of,
and not in addition to, or shall be deemed to be any notice required under any
provision of applicable law, and (iv) not be deemed a forfeiture or a
termination of this Lease unless Landlord elects otherwise in such notice;
provided that if the nature of Tenant's default is such that it cannot be cured
by the payment of money and reasonably requires more than 30 days to cure, then
Tenant shall not be deemed to be in default if Tenant commences such cure within
said 30 day period and thereafter diligently prosecutes the same to completion,
provided, however, that such cure shall be completed no later than 90 days from
the date of Landlord's notice.

         22.      LANDLORD'S REMEDIES.

         (a)      PAYMENT BY LANDLORD; INTEREST. Upon a Default by Tenant
hereunder, Landlord may, without waiving or releasing any obligation of Tenant
hereunder, make such payment or perform such act. All sums so paid or incurred
by Landlord, together with interest thereon, from the date such sums were paid
or incurred, at the annual rate equal to 12% per annum or the highest rate
permitted by law (the "DEFAULT, RATE"), whichever is less, shall be payable to
Landlord on demand as additional Rent. Nothing herein shall be construed to
create or impose a duty on Landlord to mitigate any damages resulting from
Tenant's Default hereunder.

         (b)      LATE PAYMENT RENT. Late payment by Tenant to Landlord of Rent
and other sums due will cause Landlord to incur costs not contemplated by this
Lease, the exact amount of which will be extremely difficult and impracticable
to ascertain. Such costs include, but are not limited to, processing and
accounting charges and late charges which may be imposed on Landlord under any
mortgage or trust deed covering the Premises. Therefore, if any installment of
Rent due from Tenant is not received by Landlord within 5 days after the date
such payment is due, Tenant shall pay to Landlord an additional sum of 6% of the
overdue Rent as a late charge. The parties agree that this late charge
represents a fair and reasonable estimate of the costs Landlord will incur by
reason of late payment by Tenant. In addition to the late charge, Rent not paid
when due shall bear interest at the Default Rate from the 5th day after the date
due until paid. Notwithstanding the foregoing, no late charge nor interest shall
be due on the first such failure to pay Rent in any 12 month period until 5 days
after Landlord has given Tenant notice of such failure to pay Rent and Tenant
has failed so to pay Rent within such 5 day period. Any such notice shall be in
lieu of and not in addition to any notice required by law.

         (c)      REMEDIES. Upon and during the continuance of a Default,
Landlord, at its option, without further notice or demand to Tenant, shall have
in addition to all other rights and remedies provided in this Lease, at law or
in equity, the option to pursue any one or more of the following remedies, each
and all of which shall be cumulative and nonexclusive, without any notice or
demand whatsoever. No cure in whole or in part of such Default by Tenant after
Landlord has taken any action beyond giving Tenant notice of such Default to
pursue any remedy provided for herein (including retaining counsel to file an
action or otherwise pursue any remedies) shall in any way affect Landlord's
right to pursue such remedy or any other remedy provided Landlord herein or
under law, unless Landlord, in its sole discretion, elects to waive such
Default.

                  (i) This Lease and the Term and estate hereby granted are
         subject to the limitation that whenever a Default shall have happened
         and be continuing, Landlord shall have the right, at its election,
         then or thereafter while any such Default shall continue and
         notwithstanding the fact that Landlord may have some other remedy
         hereunder or at law or in equity, to give Tenant written notice of
         Landlord's intention to terminate this Lease on a date specified in
         such notice, which date shall be not less than five (5) days after the
         giving of such notice, and upon the date so specified, this Lease and
         the estate hereby granted shall expire and terminate with the same
         force and effect as if the date specified in such notice were the date
         hereinbefore fixed for the expiration of this Lease, and all right of
         Tenant hereunder shall expire and terminate, and Tenant shall be
         liable as hereinafter in this Section 22(c) provided. If any such
         notice is given, Landlord shall have, on such date so specified, the
         right of re-entry and possession of the Premises and the right to
         remove all persons and property therefrom and to store such property in
         a warehouse or elsewhere at the risk and expense, and for the account,
         of Tenant. Should Landlord elect to re-enter as herein provided or
         should landlord take

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         possession pursuant to legal proceedings or pursuant to any notice
         provided for by law, Landlord may from time to time re-let the remises
         or any part thereof for such term or terms and at such rental or
         rentals and upon such terms and conditions as Landlord may deem
         advisable, with the right to make commercially reasonable alterations
         in and repairs to the Premises.

                  (ii) In the event of any termination of this Lease as in this
         Article 22 provided or as required or permitted by law, Tenant shall
         forthwith quit and surrender the Premises to Landlord, and Landlord
         may, without further notice, enter upon, re-enter, possess and
         repossess the same by summary proceedings, ejectment or otherwise, and
         again have, repossess and enjoy the same as if this Lease had not been
         made, and in any such event Tenant and no person claiming through or
         under Tenant by virtue of any law or an order of any court shall be
         entitled to possession or to remain in possession of the premises by
         shall forthwith quit and surrender the Premises. Landlord, at its
         option, notwithstanding any other provision of this Lease, shall be
         entitled to recover from Tenant, as and for liquidated damages, the sum
         of;

                           (A) all Base Rent, Additional Rent and other amounts
                  payable by Tenant hereunder then due or accrued and unpaid,
                  and

                           (B) the amount equal to the aggregate of all unpaid
                  Base Rent and Additional Rent which would have been payable if
                  this Lease had not been terminated prior to the end of the
                  Term then in effect, discounted to its then present value in
                  accordance with accepted financial practice using a rate of
                  five percent (5%) per annum, for loss of the bargain; and

                           (C) all other damages and expenses (including
                  attorneys' fees and expenses), if any, which Landlord shall
                  have sustained by reason of the breach of any provision of
                  this Lease; less

                           (D) the net proceeds of any re-letting actually
                  received by Landlord and (ii) the amount of damages which
                  Tenant proves could have been avoided had Landlord taken
                  reasonable steps to mitigate its damages.

                  (iii) Nothing herein contained shall limit or prejudice the
         right of Landlord, in any bankruptcy or insolvency proceeding, to prove
         for and obtain as liquidated damages by reason of such termination an
         amount equal to the maximum allowed by any bankruptcy or insolvency
         proceedings, or to prove for and obtain as liquidated damages by reason
         of such termination, an amount equal to the maximum allowed by any
         statute or rule of law whether such amount shall be greater or less
         than the excess referred to above.

                  (iv) Nothing in this Article 22 shall be deemed to affect the
         right of either party to indemnifications pursuant to this Lease.

                  (v) If Landlord terminates this Lease upon the occurrence of a
         Default, Tenant will quit and surrender the Premises to Landlord or its
         agents, and Landlord may, without further notice, enter upon, re-enter
         and repossess the Premises by summary proceedings, ejectment or
         otherwise. The words "enter", "re-enter", and "re-entry" are not
         restricted to their technical legal meanings.

                  (vi) If either party shall be in default in the observance or
         performance of any provision of this Lease, and an acton shall be
         brought for the enforcement thereof in which it shall be determined
         that such party was in default, the party in default shall pay to the
         other all fees, costs and other expenses which may become payable as a
         result thereof or in connection therewith, including attorneys' fees
         and expenses.

                  (vii) If Tenant shall default in the keeping, observance or
         performance of any covenant, agreement, term, provision or condition
         herein contained, Landlord, without thereby waiving such default, may
         perform the same for the account and at the expenses of Tenant (a)
         immediately or at any time thereafter and without notice in the case of
         emergency or in case such default will result in

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<PAGE>

         a violation of any legal or insurance requirements, or in the
         imposition of any lien against all or any portion of the Premises, and
         (b) in any other case if such default continues after any applicable
         the cure period provided in Article 21. All reasonable costs and
         expenses incurred by Landlord in connection with any such performance
         by it for the account of Tenant and also all reasonable costs and
         expenses, including attorneys' fees and disbursements incurred by
         Landlord in any action or proceeding (including any summary dispossess
         proceeding) brought by Landlord to enforce any obligation of Tenant
         under this Lease and/or right of Landlord in or the Premises, shall be
         paid by Tenant to Landlord within ten (10) days after demand.

                  (viii) Except as otherwise provided in this Article 22, no
         right or remedy herein conferred upon or reserved to Landlord is
         intended to be exclusive of any other right or remedy, and every right
         and remedy shall be cumulative an din addition to any other legal or
         equitable right or remedy given hereunder, or now or hereafter
         existing. No waiver of any provision of this Lease shall be deemed to
         have been made unless expressly so made in writing. Landlord shall be
         entitled, to the extent permitted by law, to seek injunctive relief in
         case of the violation, or attempted or threatened violation, of any
         provision of this Lease, or to seek a decree compelling observance or
         performance of any provision of this Lease, or to seek any other legal
         or equitable remedy.

         23.      ASSIGNMENT AND SUBLETTING.

         (a)      GENERAL PROHIBITION. Without Landlord's prior written consent,
Tenant shall not, directly or indirectly, voluntarily or by operation of law,
assign this Lease or sublease the Premises or any part thereof or mortgage,
pledge, or hypothecate its leasehold interest or grant any concession or license
within the Premises and any attempt to do any of the foregoing shall be void and
of no effect. For purposes of this Section, a transfer of ownership interests
controlling Tenant (other than in connection with one or more public offerings
of the capital stock of Tenant) shall be deemed an assignment of this Lease
unless such ownership interests are publicly traded. Notwithstanding the
foregoing, Tenant shall have the right to assign its interest under this Lease
and/or to sublet its interest in the Premises (an "APPROVED TRANSFER") to any
entity: (i) which has 50% or more of the issued or outstanding shares of
Tenant's stock; or (ii) in which Tenant or Tenant's 50% or greater owner has
more than 50% or more of ownership interest; or (iii) into which Tenant is
merged, with which Tenant is consolidated, or which acquires all or
substantially all of the assets of Tenant (collectively, an "APPROVED
TRANSFEREE"), provided that the Approved Transferee first executes, acknowledges
and delivers to Landlord an agreement whereby the Approved Transferee agrees to
be bound by all of the covenants and agreements in this Lease and that the
Approved Transferee shall have a net worth (determined in accordance with
generally accepted accounting principals consistently applied) immediately after
such Approved Transfer which is at least equal to the net worth (as so
determined) of Tenant immediately prior to the Approved Transfer (or as of the
date hereof, if greater). Tenant shall provide 15 days prior written notice of
an Approved Transfer to Landlord.

         (b)      PERMITTED TRANSFERS. If Tenant desires to assign, sublease,
hypothecate or otherwise transfer this Lease or sublet the Premises, then Tenant
shall give Landlord notice (a "PRELIMINARY ASSIGNMENT NOTICE) setting forth the
terms and conditions on which Tenant proposes to offer the Premises, including
the date on which tenant wishes to vacate for its own use such portion of the
Premises (the "EFFECTIVE DATE"), or any portion thereof, to third parties.
Landlord shall, within 10 business days of receipt of such Preliminary
Assignment Notice elect to exercise, or waive, its right to terminate this Lease
with respect to the space described in the Preliminary Assignment Notice for the
term of the assignment or sublease proposed in such Preliminary Assignment
Notice, as of the Effective Date (an "ASSIGNMENT TERMINATION"). If Landlord
elects an Assignment Termination, Tenant shall have the right to withdraw such
Preliminary Assignment Notice by written notice to Landlord of such election
within 5 days after Landlord's notice electing to exercise the Assignment
Termination. If Tenant withdraws such Preliminary Assignment Notice, this Lease
shall continue in full force and effect. If Tenant does not withdraw such
Preliminary Assignment Notice, this Lease, and the term and estate herein
granted, shall terminate as of the Effective Date with respect to the space
described in such Preliminary Assignment Notice. No failure of Landlord to
exercise any such option to terminate this Lease with respect to all or any
portion of the premises in response to a Preliminary Assignment Notice shall be
deemed to be Landlord's consent to the proposed assignment, subletting or other
transfer, and Landlord hereby reserves and Tenant hereby acknowledges,
Landlord's right to approve or

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<PAGE>

disapprove any assignment or any subletting which individually or taken together
with all then effective prior subleases, results in 50% or more of the Premises
being sublet, in its sole discretion. Landlord shall grant or withhold its
consent to any subletting which individually or taken together with all then
effective prior subleases, results in less than 50% of the Premises being
sublet, in its reasonable discretion.

         Except for Approved Transfers, at least 15 business days, but not more
than 90 days, before the date the instrument effecting such assignment or
subletting is to be executed and delivered (the "ASSIGNMENT DATE"), Tenant shall
give Landlord a notice (the "ASSIGNMENT NOTICE") containing all of the relevant
terms and conditions upon which Tenant is willing to assign the Lease or to
sublet all or any portion of the Premises, including such information about the
proposed assignee or sublessee, including the proposed use of the Premises and
any Hazardous Materials proposed to be used or stored in the Premises, the
Assignment Date, any relationship between Tenant and the proposed assignee or
sublessee, and all material terms and conditions of the proposed assignment or
sublease, and such other information as Landlord may deem reasonably necessary
or appropriate to its consideration whether to grant its consent. Landlord may,
by giving written notice to Tenant within 15 business days after receipt of the
Assignment Notice grant or refuse such consent, in its sole discretion with
respect to any assignment or any subletting which individually or taken together
with all then effective prior subleases, results in 50% or more of the Premises
being sublet, or in its reasonable discretion with respect to any subletting
which individually or taken together with all then effective prior subleases,
results in less than 50% of the Premises being sublet. Tenant shall reimburse
Landlord for all of Landlord's reasonable out-of-pocket expenses in connection
with its consideration of any Assignment Notice.

         (c)      ADDITIONAL CONDITIONS. As a condition to any such assignment
or subletting, Landlord may require:

                  (i) that any assignee or subtenant agree, in writing at the
         time of such assignment or subletting, that if Landlord gives such
         third party notice Tenant is in Default under this Lease, such third
         party shall thereafter make all payments otherwise due Tenant directly
         to Landlord, which payments will be received by Landlord without any
         liability except to credit such payment against those due under the
         Lease, and any such third party shall agree to attorn to Landlord or
         its successors and assigns should this Lease be terminated for any
         reason; provided, however, in no event shall Landlord or its successors
         or assigns be obligated to accept such attornment; and

                  (ii) A list of Hazardous Materials, certified by the proposed
         assignee or sublessee to be true and correct, which the proposed
         assignee or sublessee intends to use or store in the Premises together
         with the Documents referred to in Section 31(b) with respect to such
         proposed assignee or sublessee.

         (d)      NO RELEASE OF TENANT. Notwithstanding any assignment or
subletting, Tenant and any guarantor or surety of Tenant's obligations under
this Lease shall at all times remain fully and primarily responsible and liable
for the payment of Rent and for compliance with all of Tenant's other
obligations under this Lease. If the Rent due and payable by a sublessee or
assignee (or a combination of the rental payable under such sublease or
assignment plus any bonus or other consideration therefor or incident thereto)
exceeds the rental payable under this lease together with Tenant's reasonable
costs of subletting or assigning such portion of the Premises, then Tenant shall
be bound and obligated to pay Landlord as additional Rent hereunder 50% of such
excess rental and other excess consideration within 10 days following receipt
thereof by Tenant If Tenant shall sublet the Premises or any part thereof,
Tenant hereby immediately and irrevocably assigns to Landlord, as security for
Tenant's obligations under this Lease, all rent from any such subletting and
Landlord as assignee of Tenant, or a receiver for Tenant appointed on Landlord's
application, may collect such rent and apply it toward Tenant's obligations
under this Lease; except that, until the occurrence of a Default, Tenant shall
have the right to collect such rent.

         (e)      NO WAIVER. The consent by Landlord to an assignment or
subletting shall not relieve Tenant or any assignees of this Lease or any
sublessees of the Premises from obtaining the consent of Landlord to any further
assignment or subletting nor shall it release Tenant or any assignee or
sublessee of Tenant from full and primary liability under the Lease. The
acceptance of Rent hereunder, or the acceptance of

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<PAGE>

performance of any other term, covenant, or condition thereof, from any other
person or entity shall not be deemed to be a waiver of any of the provisions of
this Lease or a consent to any subletting, assignment or other transfer of the
Premises.

         24.      ESTOPPEL CERTIFICATE. Tenant shall within 10 business days of
written notice from Landlord, execute, acknowledge and deliver a statement in
writing substantially in the form attached to this Lease as Exhibit G with the
blanks filled in, and on any other form reasonably requested by a proposed
lender or purchaser, (i) certifying that this Lease is unmodified and in full
force and effect (or, if modified, stating the nature of such modification and
certifying that this Lease as so modified is in full force and effect) and the
dates to which the rental and other charges are paid in advance, if any, (ii)
acknowledging that there are not, to Tenant's knowledge, any uncured defaults on
the part of Landlord hereunder, or specifying such defaults if any are claimed
and (iii) setting forth such further information with respect to the status of
this Lease or the Premises as may be requested thereon. Any such statement may
be relied upon by any prospective purchaser or encumbrancer of all or any
portion of the real property of which the Premises are a part. Tenant's failure
to deliver such statement within such time shall, at the option of Landlord,
constitute a Default under this Lease, and, in any event, shall be conclusive
upon Tenant that the Lease is in full force and effect and without modification
except as may be represented by Landlord in any certificate prepared by Landlord
and delivered to Tenant for execution. Landlord shall similarly execute,
acknowledge and deliver a statement in writing upon request of Tenant in
connection with any transaction in which Tenant is involved: (i) certifying that
this Lease is unmodified and in full force and effect (or, if modified, stating
the nature of such modification and certifying that this Lease as so modified is
in full force and effect) and the dates to which the rental and other charges
are paid in advance, if any, (ii) acknowledging that there are not, to
Landlord's knowledge, any uncured defaults on the part of Tenant hereunder, or
specifying such defaults if any are claimed and (iii) setting forth such further
information with respect to the status of this Lease or the Premises as may be
requested thereon.

         25.      QUIET ENJOYMENT. If Tenant shall perform all of the covenants
and agreements herein required to be performed by Tenant, Tenant shall, subject
to the terms of this Lease, at all times during the Term, have peaceful and
quiet enjoyment of the Premises against any person claiming by, through or under
Landlord.

         26.      PRORATIONS. ALL prorations required or permitted to be made
hereunder shall be made on the basis of a 360 day year and 30 day months.

         27.      RULES AND REGULATIONS. Tenant shall, at all times during the
Term and any extension thereof, comply with all reasonable rules and regulations
at any time or from time to time established by Landlord covering use of the
Premises and the Project. The current rules and regulations are attached hereto.
If there is any conflict between said rules and regulations and other provisions
of this Lease, the terms and provisions of this Lease shall control. Landlord
shall not have any liability or obligation for the breach of any rules or
regulations by other tenants in the Project.

         28.      SUBORDINATION. This Lease and Tenant's interest and rights
hereunder are and shall be subject and subordinate at all times to the lien of
any first mortgage, now existing or hereafter created on or against the Project
or the Premises, and all amendments, restatements, renewals, modifications,
consolidations, refinancing, assignments and extensions thereof, without the
necessity of any further instrument or act on the part of Tenant; provided,
however that so long as there is no Default hereunder, Tenant's rights hereunder
shall not be disturbed by the holder of any such first mortgage. Tenant agrees,
at the election of the holder of any such mortgage, to attorn to any such
holder. Tenant agrees upon demand to execute, acknowledge and deliver a
Subordination, Non-disturbance and Attornment Agreement in the form attached
hereto as Exhibit H, or such other instruments, confirming such subordination
and such instruments of attornment as shall be requested by any such holder,
provided any such instruments contain appropriate non-disturbance provisions
assuring Tenant's quiet enjoyment of the Premises as set forth in Section 25
hereof. Notwithstanding the foregoing, any such holder may at any time
subordinate its mortgage to this Lease, without Tenant's consent, by notice in
writing to Tenant, and thereupon this Lease shall be deemed prior to such
mortgage without regard to their respective dates of execution, delivery or
recording and in that event such holder shall have the same rights with respect
to this Lease as though this Lease had been

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executed prior to the execution, delivery and recording of such mortgage and had
been assigned to such holder. The term "MORTGAGE" whenever used in this Lease
shall be deemed to include deeds of trust, security assignments and any other
encumbrances, and any reference to the "HOLDER" of a mortgage shall be deemed to
include the beneficiary under a deed of trust.

         29.      SURRENDER. Upon expiration of the Term or earlier termination
of Tenant's right of possession, Tenant shall surrender the Premises to Landlord
in the same condition as received, subject to any Alterations permitted by
Landlord to remain in the Premises, free of Hazardous Materials brought upon,
kept or used in or about the Premises or the Project by Tenant, its agents,
employees, contractors or invitees and released of all licenses and/or permits
which restrict the use of the Premises, broom clean, ordinary wear and tear and
casualty loss and condemnation covered by Sections 19 and 20 excepted. Tenant
shall return to Landlord all keys and/or access cards to parking, the Project,
restrooms or all or any portion of the Premises furnished to or otherwise
procured by Tenant. If any such access card or key is lost, Tenant shall pay to
Landlord, at Landlord's election, either the cost of replacing such lost access
card or key or the cost of reprogramming the access security system in which
such access card was used or changing the lock or locks opened by such lost key.
Any Tenant's Property, Alterations and property not so removed by Tenant as
permitted or required herein shall be deemed abandoned and may be stored,
removed, and disposed of by Landlord at Tenant's expense, and Tenant waives all
claims against Landlord for any damages resulting from Landlord's retention
and/or disposition of such property. All obligations of Tenant hereunder not
fully performed as of the termination of the Term, including the obligations of
Tenant under Section 30 hereof, shall survive the expiration or earlier
termination of the Term, including without limitation, indemnity obligations,
payment obligations with respect to Rent and obligations concerning the
condition and repair of the Premises.

         30.      WAIVER OF JURY TRIAL. TENANT AND LANDLORD WAIVE ANY RIGHT TO
TRIAL BY JURY OR TO HAVE A JURY PARTICIPATE IN RESOLVING ANY DISPUTE, WHETHER
SOUNDING IN CONTRACT, TORT, OR OTHERWISE, BETWEEN LANDLORD AND TENANT ARISING
OUT OF THIS LEASE OR ANY OTHER INSTRUMENT, DOCUMENT, OR AGREEMENT EXECUTED OR
DELIVERED IN CONNECTION HEREWITH OR THE TRANSACTIONS RELATED HERETO.

         31.      ENVIRONMENTAL REQUIREMENTS.

         (a)      PROHIBITION/COMPLIANCE. Tenant shall not cause or permit any
Hazardous Materials (as hereinafter defined) to be brought upon, kept or used in
or about the Premises or the Project by Tenant, its agents, employees,
contractors or invitees in violation of applicable law. If Tenant breaches the
obligation stated in the preceding sentence, or if the presence of Hazardous
Materials brought upon, kept or used in or about the Premises or the Project by
Tenant, its agents; employees, contractors or invitees results in contamination
of the Premises, the Project or any adjacent property or if contamination of the
Premises, the Project or any adjacent property by Hazardous Materials brought
upon, kept or used in or about the Premises or the Project in violation of
applicable law by Tenant, its agents, employees, contractors or invitees
otherwise occurs during the term of this Lease or any extension or renewal
hereof or holding over hereunder, Tenant hereby indemnifies and shall defend and
hold Landlord, its officers, directors, employees, agents and contractors
harmless from any and all claims, judgments, damages, penalties, fines, costs,
liabilities, or losses (including, without limitation, diminution in value of
the Premises or any portion of the Project, damages for the loss or restriction
on use of rentable or usable space or of any amenity of the Premises or the
Project, damages arising from any adverse impact on marketing of space in the
Premises or the Project, and sums paid in settlement of claims, attorneys' fees,
consultant fees and expert fees) which arise during or after the Lease term as a
result of such contamination. This indemnification of Landlord by Tenant
includes, without limitation, costs incurred in connection with any
investigation of site conditions or any cleanup, remedial, removal, or
restoration work required by any federal, state or local governmental agency or
political subdivision because of Hazardous Materials brought upon, kept or used
in or about the Premises or the Project by Tenant, its agents, employees,
contractors or invitees present in the air, soil or ground water above on or
under the Premises. Without limiting the foregoing, if the presence of any
Hazardous Materials on the Premises, the Building, the Project or any adjacent
property, caused or permitted by Tenant results in any contamination of the
Premises, the Project or any adjacent property, Tenant shall promptly take all
actions at its sole expense as are necessary to return the Premises, the Project
or any adjacent property, to the condition existing prior to the time of such
contamination, provided that Landlord's approval of such action

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<PAGE>

shall first be obtained, which approval shall not unreasonably be withheld so
long as such actions would not potentially have any material adverse long-term
or short-term effect on the Premises or the Project.

         (b)      BUSINESS. Landlord acknowledges that it is not the intent of
this Article 31 to prohibit Tenant from operating its business as described
above. Tenant may operate its business according to the custom of the industry
so long as the use or presence of Hazardous Materials is strictly and properly
monitored according to all applicable governmental requirements. As a material
inducement to Landlord to allow Tenant to use Hazardous Materials in connection
with its business, Tenant agrees to deliver to Landlord prior to the Rent
Commencement Date a list identifying each type of Hazardous Materials to be
present on the Premises and setting forth any and all governmental approvals or
permits required in connection with the presence of such Hazardous Materials on
the Premises ("HAZARDOUS MATERIALS LIST"). Tenant shall deliver to Landlord an
updated Hazardous Materials List at least once a year and shall also deliver an
updated list before any new Hazardous Materials is brought onto the Premises.
Tenant shall deliver to Landlord true and correct copies of the following
documents (the "DOCUMENTS") relating to the handling, storage, disposal and
emission of Hazardous Materials prior to the Rent Commencement Date, or if
unavailable at that time, concurrent with the receipt from or submission to a
governmental agency: permits; approvals; reports and correspondence; storage and
management plans, notice of violations of any laws; plans relating to the
installation of any storage tanks to be installed in or under the Project
(provided, said installation of tanks shall only be permitted after Landlord has
given Tenant its written consent to do so, which consent may be withheld in
Landlord's sole and absolute discretion); and all closure plans or any other
documents required by any and all federal, state and local governmental agencies
and authorities for any storage tanks installed in, on or under the Project for
the closure of any such tanks. Tenant is not required, however, to provide
Landlord with any portion(s) of the Documents containing information of a
proprietary nature which, in and of themselves, do not contain a reference to
any Hazardous Materials or hazardous activities. It is not the intent of this
Section to provide Landlord with information which could be detrimental to
Tenant's business should such information become possessed by Tenant's
competitors.

         (c)      TERMINATION OF LEASE. Notwithstanding the provisions of
Section 31(a) above, if as of the date hereof: (i) Tenant has been required by
any prior landlord, lender or governmental authority to take remedial action in
connection with Hazardous Materials contaminating a property if the
contamination resulted from Tenant's action or use of the property in question
("MANDATED REMEDIATION"), or (ii) Tenant is subject to an enforcement order
issued by any governmental authority in connection with the use, disposal or
storage of a Hazardous Materials ("REMEDIATION ORDER"), in either case which is
not fully described on Schedule 31(c) attached hereto, Landlord shall have the
right to terminate this Lease in Landlord's sole and absolute discretion.
Further, it shall not be unreasonable for Landlord to withhold its consent to
any proposed assignment or subletting with respect to any proposed assignee or
sublessee who has so been required to undertake any Mandated Remediation or who
is subject to a Remediation Order.

         (d)      TESTING. Landlord shall have the right to conduct annual tests
of the Premises to determine whether any contamination has occurred as a result
of Tenant's use. Tenant shall be required to pay the cost of such annual test of
the Premises; provided, however, that if Tenant conducts its own tests of the
Premises using third party contractors and test procedures reasonably acceptable
to Landlord which tests are certified to Landlord, Landlord shall accept such
tests in lieu of the annual tests to be paid for by Tenant. In addition, at any
time, and from time to time, prior to the expiration or earlier termination of
the Term, prior to the expiration or earlier termination of the Term, Landlord
shall have the right to conduct appropriate tests of the Premises and the
Project to demonstrate that contamination has occurred as a result of Tenant's
use of the Premises. If contamination has occurred for which Tenant is liable
under this Section 31, Tenant shall pay all costs to conduct such tests. If no
such contamination is found, Landlord shall pay the costs of such tests (which
shall not constitute an Operating Expense). Landlord shall provide Tenant with a
copy of all reports and tests of the Premises made by or on behalf of Landlord.
Tenant shall be solely responsible for and shall defend, indemnify and hold the
Landlord, its agents and contractors harmless from and against any and all
claims, costs and liabilities including reasonable attorneys' fees, charges and
disbursements, arising out of or in connection with any removal, clean up,
restoration and materials required hereunder to return the Premises and any
other property of whatever nature to their condition existing prior to the time
of any such contamination.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 20]

<PAGE>

         (e)      UNDERGROUND TANKS. If underground or other storage tanks
storing Hazardous Materials are located on the Premises or are hereafter placed
on the Premises by any party, Tenant shall monitor the storage tanks, maintain
appropriate records, implement reporting procedures, properly close any
underground storage tanks, and take or cause to be taken all other steps
necessary or required under applicable state and federal law, as such now exists
or may hereafter be adopted or amended.

         (f)      TENANT'S OBLIGATIONS. Tenant's obligations under this Article
30 shall survive the expiration or earlier termination of the Lease. During any
period of time after the expiration or earlier termination of this Lease
required by Tenant or Landlord to complete the removal from the Premises of any
Hazardous Materials and the release and termination of any licenses or permits
restricting the use of the Premises, Tenant shall continue to pay the full Rent
in accordance with this Lease for any portion of the Premises not relet by
Landlord in Landlord's sole discretion, which Rent shall be prorated daily.

         (g)      DEFINITION OF "HAZARDOUS MATERIALS." As used herein, the term
"HAZARDOUS MATERIALS" means any hazardous or toxic substance, material or waste
which is or becomes regulated by any local governmental authority, the State of
New Jersey or the United States government and includes, without limitation, any
material or substance which is (i) defined as a "hazardous waste," "extremely
hazardous waste," "hazardous material," "hazardous substance" or "restricted
hazardous waste" under any applicable New Jersey Law, (ii) designated as a
"hazardous substance" pursuant to Section 311 of the Federal Water Pollution
Control Act (33 U.S.C. Section 1317), (iii) defined as a "hazardous waste"
pursuant to Section 1004 of the Federal Resource Conversation and Recovery Act,
42 U.S.C. Section 6901, et. seq. (42 U.S.C. Section 6903), or (iv) defined as a
"hazardous substance" pursuant to Section 101 of the Comprehensive Environmental
Response Compensation and Liability Act, 42 U.S.C. Section 9601 et. seq. (42
U.S.C. Section 9601).

         32.      TENANT'S REMEDIES/LIMITATION OF LIABILITY. Landlord shall not
be in default hereunder unless Landlord fails to perform any of its obligations
hereunder within 30 days after written notice from Tenant specifying such
failure (unless such performance will, due to the nature of the obligation,
require a period of time in excess of 30 days, then after such period of time as
is reasonably necessary provided landlord diligently pursue such cure). Upon any
default by Landlord, Tenant shall give notice by registered or certified mail to
any beneficiary of a deed of trust or mortgagee or a mortgage covering the
Premises and to any landlord of any lease of property in or on which the
Premises are located and Tenant shall offer such beneficiary, mortgagee and/or
landlord a reasonable opportunity to cure the default, including time to obtain
possession of the Project by power of sale or a judicial action if such should
prove necessary to effect a cure; provided Landlord shall have furnished to
Tenant in writing the names and addresses of all such persons who are to receive
such notices.

         Notwithstanding the foregoing, if any claimed Landlord default
hereunder will immediately, materially and adversely affect Tenant's ability to
conduct its business in the Premises (a "MATERIAL LANDLORD DEFAULT"), Tenant
shall, as soon as reasonably possible, but in any event within 2 business days
of obtaining knowledge of such claimed Material Landlord Default, give Landlord
written notice of such claim and telephonic notice to Tenant's principal contact
with Landlord. Landlord shall then have 2 business days to commence cure of such
claimed Material Landlord Default and shall diligently prosecute such cure to
completion. If such claimed Material Landlord Default is not a default by
Landlord hereunder, or if Tenant failed to give Landlord the notice required
hereunder within 2 business days of learning of the conditions giving rise to
the claimed Material Landlord Default, Landlord shall be entitled to recover
from Tenant, as Additional Rent, any costs incurred by Landlord in connection
with such cure in excess of the costs, if any, that Landlord would otherwise
have incurred. If Landlord fails to commence cure of any claimed Material
Landlord Default as provided above, Tenant may commence and prosecute such cure
to completion, and shall be entitled to recover the costs of such cure (but not
any consequential or other damages) from Landlord, to the extent of Landlord's
obligation to cure such claimed Material Landlord Default hereunder, subject to
the limitations set forth in the immediately preceding sentence of this
paragraph and the other provisions of this Lease.

         All obligations of Landlord hereunder shall be construed as covenants,
not conditions; and, except as may be otherwise expressly provided in this
Lease, Tenant may not terminate this Lease for breach of Landlord's obligations
hereunder. All obligations of Landlord under this Lease will be binding upon
Landlord

              [100 Philips Parkway/Memory Pharmaceuticals- Page 21]

<PAGE>

only with respect to the period of its ownership of the Premises and not
thereafter. The term "LANDLORD" in this Lease shall mean only the owner, for the
time being of the Premises, and upon the transfer by such owner of its interest
in the Premises, such owner shall thereupon be released and discharged from all
obligations of Landlord thereafter accruing, but such obligations shall be
binding during the Term upon each new owner for the duration of such owner's
ownership. Any liability of Landlord under this Lease shall be limited solely to
its interest in the Project, and in no event shall any personal liability be
asserted against Landlord in connection with this Lease nor shall any recourse
be had to any other property or assets of Landlord or any of Landlord's
officers, employees, agents or contractors. Under no circumstances shall
Landlord or any of Landlord's officers, employees, agents or contractors be
liable for injury to Tenant's business or for any loss of income or profit
therefrom.

         33.      INSPECTION AND ACCESS. Landlord and its agents,
representatives, and contractors may enter the Premises at any reasonable time,
after providing Tenant with not less than 2 days prior written notice, except in
the case of an emergency (in which event Landlord shall promptly notify Tenant
of such entry) to inspect the Premises and to make such repairs as may be
required or permitted pursuant to this Lease and for any other business purpose.
Landlord and Landlord's representatives may enter the Premises, after providing
Tenant with not less than 2 days prior written notice, during business hours for
the purpose of showing the Premises to prospective purchasers and, during the
last year of the Term, to prospective tenants. Landlord may erect a suitable
sign on the Premises stating the Premises are available to let or that the
Project is available for sale. Landlord may grant easements, make public
dedications, designate common areas and create restrictions on or about the
Premises, provided that no such easement, dedication, designation or restriction
materially interferes with Tenant's use or occupancy of the Premises. At
Landlord's request. Tenant shall execute such instruments as may be reasonably
necessary for such easements, dedications or restrictions. Notwithstanding the
foregoing, Tenant shall at all times, except in the case of emergencies, have
the right to escort Landlord or its agents, representative, contractors or
guests while the same are on the Premises. Tenant shall have 24 hour per day,
365 day per year access to the Premises, subject to the other provisions of this
Lease.

         34.      SECURITY. Tenant acknowledges and agrees that security devices
and services, if any, while intended to deter crime may not in given instances
prevent theft or other criminal acts and that Landlord is not providing any
security services with respect to the Premises. Tenant agrees that Landlord
shall not be liable to Tenant for, and Tenant waives any claim against Landlord
with respect to, any loss by theft or any other damage suffered or incurred by
Tenant in connection with any unauthorized entry into the Premises or any other
breach of security with respect to the Premises. Tenant shall be solely
responsible for the personal safety of Tenant's officers, employees, agents,
contractors, guests and invitees while any such person is in, on or about the
Premises and/or the Project. Tenant shall at Tenant's cost obtain insurance
coverage to the extent Tenant desires protection against such criminal acts.

         35.      FORCE MAJEURE. Neither party shall be held responsible for
delays in the performance of its obligations hereunder when caused by strikes,
lockouts, labor disputes, acts of God, inability to obtain labor or materials or
reasonable substitutes therefor (other than by reason of such party's inability
to pay for such labor or materials), governmental restrictions, governmental
regulations, governmental controls, delay in issuance of permits (other than by
reason of such party's inability to pay for such permits), enemy or hostile
governmental action, civil commotion, fire or other casualty, and other causes
beyond the reasonable control of such party ("FORCE MAJEURE").

         36.      LIMITATION ON LANDLORD'S LIABILITY. NOTWITHSTANDING ANYTHING
SET FORTH HEREIN OR IN ANY OTHER AGREEMENT BETWEEN LANDLORD AND TENANT TO THE
CONTRARY: (A) LANDLORD SHALL NOT BE LIABLE (EXCEPT TO THE EXTENT OF ANY
INSURANCE PROCEEDS AVAILABLE AS A CONSEQUENCE OF ANY SUCH LOSS) TO TENANT OR ANY
OTHER PERSON FOR (AND TENANT AND EACH SUCH OTHER PERSON ASSUME ALL RISK OF)
LOSS, DAMAGE OR INJURY, WHETHER ACTUAL OR CONSEQUENTIAL TO: TENANT'S PERSONAL
PROPERTY OF EVERY KIND AND DESCRIPTION, INCLUDING, WITHOUT LIMITATION TENANT'S
PROPERTY, EQUIPMENT, INVENTORY, SCIENTIFIC RESEARCH, SCIENTIFIC EXPERIMENTS,
LABORATORY ANIMALS, PRODUCT, SPECIMENS, SAMPLES, AND/OR SCIENTIFIC, BUSINESS,
ACCOUNTING AND OTHER RECORDS OF EVERY KIND AND DESCRIPTION KEPT AT THE PREMISES
AND ANY AND ALL INCOME

              [100 Philips Parkway/Memory Pharmaceuticals- Page 22]

<PAGE>

DERIVED OR DERIVABLE THEREFROM; (B) THERE SHALL BE NO PERSONAL RECOURSE TO
LANDLORD FOR ANY ACT OR OCCURRENCE IN, ON OR ABOUT THE PREMISES OR ARISING IN
ANY WAY UNDER THIS LEASE OR ANY OTHER AGREEMENT BETWEEN LANDLORD AND TENANT WITH
RESPECT TO THE SUBJECT MATTER HEREOF AND ANY LIABILITY OF LANDLORD HEREUNDER
SHALL BE STRICTLY LIMITED TO LANDLORD'S INTEREST IN THE PROPERTY OF WHICH THE
PREMISES ARE A PART AND ANY INSURANCE PROCEEDS PAYABLE AS A CONSEQUENCE OF ANY
SUCH LOSS.

         37.      BROKERS, ENTIRE AGREEMENT, AMENDMENT. Landlord and Tenant each
represent and warrant that it has not dealt with any broker, agent or other
person (collectively, "BROKER") in connection with this transaction and that no
Broker brought about this transaction, other than the Broker, if any, set forth
on the first page of this Lease. Landlord and Tenant each hereby agree to
indemnify and hold the other harmless from and against any claims by any other
Broker claiming a commission or other form of compensation by virtue of having
dealt with Tenant or Landlord, as applicable, with regard to this leasing
transaction. This Lease constitutes the complete agreement of Landlord and
Tenant with respect to the subject matter hereof. No representations,
inducements, promises or agreements, oral or written, have been made by Landlord
or Tenant, or anyone acting on behalf of Landlord or Tenant, including any
Brokers representing either Landlord or Tenant, which are not contained herein,
and any prior agreements, promises, negotiations, or representations are
superseded by this Lease. Tenant represents and warrants that no broker or agent
has made any representation or warranty relied upon by Tenant in Tenant's
decision to enter into this Lease. Landlord in executing this Lease does so in
reliance upon Tenant's representations and warranties contained herein. This
Lease may not be amended except by an instrument in writing signed by both
parties hereto.

         38.      SEVERABILITY. If any clause or provision of this Lease is
illegal, invalid or unenforceable under present or future laws, then and in that
event, it is the intention of the parties hereto that the remainder of this
Lease shall not be affected thereby. It is also the intention of the parties to
this Lease that in lieu of each clause or provision of this Lease that is
illegal, invalid or unenforceable, there be added, as a part of this Lease, a
clause or provision as similar in terms to such illegal, invalid or
unenforceable clause or provision as may be possible and be legal, valid and
enforceable.

         39.      SIGNS; EXTERIOR APPEARANCE. Tenant shall not, without the
prior written consent of Landlord, which may be granted or withheld In
Landlord's sole discretion: (i) attach any awnings, exterior lights,
decorations, balloons, flags, pennants, banners, painting or other projection to
any outside wall of the Project, (ii) use any curtains, blinds, shades or
screens other than Landlord's standard window coverings, (iii) coat or otherwise
sunscreen the interior or exterior of any windows, (iv) place any bottles,
parcels, or other articles on the window sills, (v) place any equipment,
furniture or other items of personal property on any exterior balcony, (vi)
paint, affix or exhibit on any part of the Premises or the Project any signs,
notices, window or door lettering, placards, decorations, or advertising media
of any type which can be viewed from the exterior of the Premises. Interior
signs on doors and the directory tablet shall be inscribed, painted or affixed
for Tenant by Landlord at the sole cost and expense of Tenant, and shall be of a
size, color and type acceptable to Landlord. Nothing may be placed on the
exterior of corridor walls or corridor doors other than Landlord's standard
lettering. The directory tablet shall be provided exclusively for the display of
the name and location of tenants.

         40.      RIGHT TO EXPAND

         (a)      EXPANSION IN THE BUILDING. Tenant shall have the right, but
not the obligation, to expand the Premises (the "EXPANSION RIGHT") to include
any space available for lease in the Project after it has initially been let to
another tenant (the "EXPANSION SPACE") upon the terms and conditions set forth
in this Section 40. If at any time Landlord has any Expansion Space available in
the Project, Landlord shall deliver to Tenant: (i) written notice of such fact
(the "EXPANSION NOTICE") describing the portion of the Expansion Space (the
"NOTICE SPACE") which is available, and (ii) a draft amendment to this Lease
(the "EXPANSION AMENDMENT") adding the Notice Space to the Premises demised
hereunder, to be leased for the then remaining Term hereof (and any Extension
Terms duly elected by Tenant) for the Market Rent at which Landlord proposes to
lease the Expansion Space, and otherwise on the same terms and conditions as are
set forth in this Lease, with appropriate adjustments to Tenant's Share. Tenant
shall have 15 business days

              [100 Philips Parkway/Memory Pharmaceuticals- Page 23]

<PAGE>

following delivery of the Expansion Notice in which to exercise the Expansion
Right by delivering to Landlord 4 fully executed copies of the Expansion
Amendment. Upon receipt, Landlord shall promptly execute two copies of such
Expansion Amendment and return them to Tenant. In addition, Tenant may, at any
time it has an Expansion Right with respect to any Expansion Space deliver a
notice to Landlord electing to Lease all or a portion of such Expansion Space
(unless the remaining Expansion Space would be 5,000 square feet or less, in
which case Tenant must elect to lease all of such Expansion Space) on the terms
described above. Any tenant improvements for such Expansion Space shall be
Tenant's sole responsibility, unless Landlord shall, at the time of any exercise
of the Expansion Right, otherwise agree. As used herein, "MARKET RENT" shall
mean the then market rental rate for the Expansion Space as determined by
Landlord, which shall in no event be less than the Base Rent payable hereunder.

         (b)      AMENDED LEASE. If Tenant fails to exercise its Expansion Right
by delivering four fully executed copies of such Expansion Amendment to Landlord
within 10 business days following delivery of the Expansion Notice, Tenant shall
be deemed to have waived its right to lease the Notice Space.

         (c)      EXCEPTIONS. Notwithstanding the above, the Expansion Right
shall not be in effect and may not be exercised by Tenant:

                  (i) during any period of time that Tenant is in Default under
         any provision of the Lease; or

                  (ii) if Tenant has been in Default under any provision of the
         Lease 3 or more times, whether or not the Defaults are cured, during
         the 12 month period prior to the date on which Tenant seeks to exercise
         the Expansion Right.

         (d)      TERMINATION. The Expansion Right shall terminate and be of no
further force or effect even after Tenant's due and timely exercise of the
Expansion Right, if, after such exercise, but prior to the commencement date of
the Expansion Space, (i) Tenant fails to timely cure any Default by Tenant under
the Lease; or (ii) Tenant has Defaulted 3 or more times during the period from
the date of the exercise of the Expansion Right to the date of the commencement
of the Expansion Space, whether or not such Defaults are cured.

         41.      MISCELLANEOUS.

         (a)      NOTICES. All notices or other communications between the
parties shall be in writing and shall be deemed duly given, if delivered in
person or by reputable overnight guaranty courier, addressed and sent to the
parties at their addresses set forth below. Landlord and Tenant may from time to
time by written notice to the other designate another address for receipt of
future notices,

         (b)      JOINT AND SEVERAL LIABILITY. If and when included within the
term "TENANT," as used in this instrument, there is more than one person, firm
or corporation, each shall be jointly and severally liable for the obligations
of Tenant.

         (c)      LANDLORD CONSENTS. Except as otherwise expressly provided in
this Lease or as otherwise required by law, Landlord retains the absolute right
to withhold any consent or approval.

         (d)      FINANCIAL INFORMATION. Tenant shall furnish Landlord with: (i)
quarterly unaudited financial statements prepared by Tenant or Tenant's
accountants for each of the first three quarters of each fiscal year during the
term hereof as soon as reasonably available and in any event within 45 days of
the close of each such fiscal quarter; (ii) audited financial statements
prepared by Tenant's accountants for each fiscal year during the term hereof as
soon as reasonably available and in any event within 90 days of the close of
each such fiscal year; (iii) an annual business plan; and (iv) any other
financial information or summaries Tenant typically provides to its lenders or
shareholders.

         (e)      RECORDATION. Neither this Lease nor a memorandum of lease
shall be filed by or on behalf of Tenant in any public record. Landlord may
prepare and file, and upon request by Landlord Tenant will execute, a memorandum
of lease.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 24]

<PAGE>

         (f)      INTERPRETATION. The normal rule of construction to the effect
that any ambiguities are to be resolved against the drafting party shall not be
employed in the interpretation of this Lease or any exhibits or amendments
hereto. Words of any gender used in this Lease shall be held and construed to
include any other gender, and words in the singular number shall be held to
include the plural, unless the context otherwise requires. The captions inserted
in this Lease are for convenience only and in no way define, limit or otherwise
describe the scope or intent of this Lease, or any provision hereof, or in any
way affect the interpretation of this Lease.

         (g)      NOT BINDING UNTIL EXECUTED. The submission by Landlord to
Tenant of this Lease shall have no binding force or effect, shall not constitute
an option for the leasing of the Premises, nor confer any right or impose any
obligations upon either party until execution of this Lease by both parties.

         (h)      LIMITATIONS ON INTEREST. It is expressly the intent of
Landlord and Tenant at all times to comply with applicable law governing the
maximum rate or amount of any interest payable on or in connection with this
Lease. If applicable law is ever judicially interpreted so as to render usurious
any interest called for under this Lease, or contracted for, charged, taken,
reserved, or received with respect to this Lease, then it is Landlord's and
Tenant's express intent that all excess amounts theretofore collected by
Landlord be credited on the applicable obligation (or, if the obligation has
been or would thereby be paid in full, refunded to Tenant), and the provisions
of this Lease immediately shall be deemed reformed and the amounts thereafter
collectible hereunder reduced, without the necessity of the execution of any new
document, so as to comply with the applicable law, but so as to permit the
recovery of the fullest amount otherwise called for hereunder.

         (i)      CHOICE OF LAW. Construction and interpretation of this Lease
shall be governed by the internal laws of the state in which the Premises are
located, excluding any principles of conflicts of laws.

         (j)      TIME. Time is of the essence as to the performance of
Landlord's and Tenant's obligations under this Lease.

         (k)      INCORPORATION BY REFERENCE. All exhibits and addenda attached
hereto are hereby incorporated into this Lease and made a part hereof. If there
is any conflict between such exhibits or addenda and the terms of this Lease,
such exhibits or addenda shall control.

         42.      RENEWAL TERMS.

         (a)      EXTENSION OF TERM.

                  (i) Tenant shall have 2 consecutive options (each, an
         "EXTENSION RIGHT") to extend the term of this Lease for 5 years each
         (each, an "EXTENSION TERM") on the same terms and conditions as the
         Lease by giving Landlord written notice of its election to exercise
         each such Extension Right at least 1 year prior to the end of the
         initial Term or any prior Extension Term. The second Extension Term may
         only be elected if Tenant has previously exercised the first Extension
         Term.

                  (ii) Base Rent shall be payable during such Extension Term at
         the Base Rent payable hereunder immediately before the commencement of
         such Extension Term, increased by 3%.

                  (iii) Extension Rights are personal to Memory Pharmaceuticals
         Corp. and are not assignable separate and apart from this Lease.

         (b)      CONDITIONS TO EXERCISE.

                  (i) Notwithstanding anything set forth above to the contrary,
         Tenant may not exercise any Extension Rights:

                           (A) during any period of time that Tenant is in
                  Default under any provision of the Lease; or

              [100 Philips Parkway/Memory Pharmaceuticals- Page 25]

<PAGE>

                           (B) if Tenant has been in Default under any provision
                  of the Lease 3 or more times, whether or not the Defaults are
                  cured, during the 12 month period prior to the date on which
                  Tenant seeks to exercise the Expansion Right or Extension
                  Right, as applicable, whether or not the Defaults are cured.

         The period of time within which any Extension Rights may be exercised
         shall not be extended or enlarged by reason of the Tenant's inability
         to exercise the Expansion Rights because of the provisions of this
         Section 42(c).

                  (ii) The Extension Rights shall terminate and be of no further
         force or effect even after Tenant's due and timely exercise of any such
         Right, if, after such exercise but prior to the commencement date of
         any Extension Term: (1) Tenant fails to timely cure any default by
         Tenant under this Lease; or (2) Tenant has defaulted 3 or more times
         during the period from the date of the exercise of any such Right to
         the date of the commencement of the Extension Term, whether or not such
         defaults are cured.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 26]

<PAGE>

         IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease as of
the day and year first above written.

TENANT:                            LANDLORD:

MEMORY PHARMACEUTICALS CORP.,      ARE - 100 PHILLIPS PARKWAY, LLC,
a Delaware corporation             a Delaware limited liability company

                                   By:  ALEXANDRIA REAL ESTATE EQUITIES, L.P.,
                                        a Delaware limited partnership, managing
                                        member

By: /s/ Joanne Leonard
    --------------------
Its: Vice President, CFO

A side Letter Agreement                 By:   ARE-QRS CORP., a Maryland
dated June 16, 1999 is being                  corporation, general partner
executed concurrent with this
Lease Agreement.                              By: /s/ LYNN ANNE SHAPIRO
                                                  -----------------------
                                                     LYNN ANNE SHAPIRO
                                              Its: GENERAL COUNSEL
[Notary seal]

              [100 Philips Parkway/Memory Pharmaceuticals- Page 27]
<PAGE>

                                   EXHIBIT A-1
                                  THE PREMISES

                                  [FLOOR PLAN]

<PAGE>

                                   EXHIBIT A-2
                                  THE PREMISES

                                  [FLOOR PLAN]

<PAGE>

                                      100 Philips Parkway/Memory Pharmaceuticals

                                    EXHIBIT B

                          LEGAL DESCRIPTION OF PROJECT

                                   (TO FOLLOW)

<PAGE>

                                   EXHIBIT B-1
                                   THE PROJECT

                                  [FLOOR PLAN]

<PAGE>

DESCRIPTION

[CHICAGO TITLE INSURANCE COMPANY LOGO]                      ORDER NO: 9824-01041
TWO UNIVERSITY PLZ STE 14
HACKENSACK NJ 07601              PHONE:(201)489-5000

ALL THAT CERTAIN TRACT, PARCEL AND LOT OF LAND LYING AND BEING SITUATE IN THE
BOROUGH OF MONTVALE, COUNTY OF BERGEN, STATE OF NEW JERSEY, BEING MORE
PARTICULARLY DESCRIBED AS FOLLOWS:

BEING KNOWN AND DESIGNED AS A PORTION OF LOT 39B IN BLOCK 65-C AS SHOWN ON A
MAP ENTITLED "FINAL SUBDIVISION PLAT, MONTVALE PARKWAY CAMPUS, BOROUGH OF
MONTVALE, COUNTY OF BERGEN, N.J." WHICH SAID MAP WAS FILED IN THE BERGEN COUNTY
CLERK'S OFFICE ON JANUARY 30, 1970 AS MAP NO. 6901 BEGIN FURTHER DESCRIBED AS
FOLLOWS:

BEGINNING AT A POINT IN THE NORTHERLY LINE OF ROAD "C" (NOW KNOWN AS VAN RIPER
ROAD) ON A MAP NUMBERED 6901 FILED JANUARY 30, 1970 IN THE BERGEN COUNTY
CLERK'S OFFICE AND ENTITLED, "FINAL SUBDIVISION PLAT, MONTVALE PARKWAY CAMPUS,
BOROUGH OF MONTVALE, COUNTY OF BERGEN, STATE OF NEW JERSEY" MADE BY EARLE W.
BAILEY, P.S. & ASSOC., CIVIL ENGINEER AND LAND SURVEYORS, HILLSDALE, NEW JERSEY,
DATED NOVEMBER, 1968, WHICH POINT IS DISTANT EASTERLY SOUTH 57 DEGREES 13
MINUTES 33 SECONDS EAST, 220.84 FEET FROM THE INTERSECTION OF THE NORTHERLY LINE
OF VAN RIPER ROAD PRODUCED WESTERLY WITH THE WESTERLY LINE OF BMW PLAZA PRODUCED
NORTHERLY AND RUNNING; THENCE

(1) NORTH 32 DEGREES 46 MINUTES 27 SECONDS EAST, 152.60 FEET TO A POINT; THENCE

(2) NORTH 15 DEGREES 47 MINUTES 00 SECONDS WEST, 294.60 FEET TO A POINT; THENCE

(3) NORTH 60 DEGREES 43 MINUTES 33 SECONDS WEST, 404.33 FEET TO THE EASTERLY
RIGHT OF WAY OF THE GARDEN STATE PARKWAY; THENCE

(4) ALONG SAID RIGHT OF WAY NORTH 29 DEGREES 16 MINUTES 27 SECONDS EAST, 735.92
FEET TO A POINT; THENCE

(5) SOUTH 57 DEGREES 32 MINUTES 23 SECONDS EAST, 491.04 FEET TO A POINT; THENCE

(6) SOUTH 08 DEGREES 40 MINUTES 22 SECONDS WEST, 265.47 FEET TO THE NORTHERLY
RIGHT OF WAY OF PHILLIPS PARKWAY; THENCE

(7) WESTERLY ALONG SAID NORTHERLY LINE OF PHILLIPS PARKWAY ON A CURVE TO THE
RIGHT, WITH A RADIUS OF 50.00 FEET, AN ARC DISTANCE OF 28.53 FEET TO A POINT OF
REVERSE CURVATURE; THENCE

(8) CONTINUING ON A CURVE TO THE LEFT WITH A RADIUS OF 60.00 FEET, AN ARC
DISTANCE OF 228.25 FEET, TO A POINT OF REVERSE CURVATURE; THENCE

(9) SOUTHEASTERLY, ON A CURVE TO THE RIGHT, WITH A RADIUS OF 30 FEET, AN ARC
DISTANCE OF 50.53 FEET TO A POINT OF TANGENCY, WHICH POINT IS THE WESTERLY LINE
OF VAN RIPER ROAD; THENCE

(10) CONTINUING ALONG SAME SOUTH 11 DEGREES 58 MINUTES 13 SECONDS WEST, 513.43
FEET

                            (CONTINUED ON NEXT PAGE)

<PAGE>

DESCRIPTION
(continued)
                                                            ORDER NO: 9824-01041

TO A POINT OF CURVATURE; THENCE

(11) ON A CURVE TO THE RIGHT WITH A RADIUS OF 152.60 FEET, AN ARC DISTANCE OF
295.11 FEET TO THE PLACE AND POINT OF BEGINNING.

BEING ALSO KNOWN AS (REPORTED FOR INFORMATIONAL PURPOSES ONLY):

LOT 2, BLOCK 3103, ON THE OFFICIAL TAX MAP OF THE BOROUGH OF MONTVALE.

                                     PAGE 2
<PAGE>

                                    EXHIBIT C

                                   WORK LETTER

         THIS WORK LETTER dated June 4, 1999 (this "WORK LETTER") is made and
entered into by and between ARE-100 Philips Parkway, LLC, a Delaware limited
liability company ("LANDLORD"), and Memory Pharmaceuticals Corp., a Delaware
corporation ("TENANT"), and is attached to and made a part of the Lease dated
June 4, 1999 (the "Lease"), by and between Landlord and Tenant. Any initially
capitalized terms used but not defined herein shall have the meanings given them
in the Lease.

1.       General Requirements

         1.1      Tenant's Authorized Representative. Tenant designates Joanne
Leonard and Charles Belotti (collectively, "TENANT'S REPRESENTATIVE") as the
only persons authorized to act for Tenant pursuant to this Work Letter. Landlord
shall not be obligated to respond to or act upon any request, approval, inquiry
or other communication ("COMMUNICATION") from or on behalf of Tenant in
connection with this Work Letter unless such Communication is in writing from
Tenant's Representative. Tenant may change Tenant's Representatives at any time
upon not less than 5 Business Days advance written notice to Landlord. No period
set forth herein for any approval of any matter by Tenant's Representative shall
be extended by reason of any change in Tenant's Representative.

         1.2      Landlord's Authorized Representative. Landlord designates
Vincent Ciruzzi ("LANDLORD'S REPRESENTATIVE") as the only person authorized to
act for Landlord pursuant to this Work Letter. Tenant shall not be obligated to
respond to or act upon any request, approval, inquiry or other Communication
from or on behalf of Landlord in connection with this Work Letter unless such
Communication is in writing from Landlord's Representative. Landlord may change
Landlord's Representatives at any time upon not less than 5 Business Days
advance written notice to Tenant. No period set forth herein for any approval of
any matter by Landlord's Representative shall be extended by reason of any
change in Landlord's Representative.

         1.3      Architects, Consultants and Contractors. The architect
("ARCHITECT"), engineering consultants, design team, general contractor
("CONTRACTOR") and all subcontractors' responsible for construction of Tenant's
Work, as defined below, shall be selected by Tenant, and approved by Landlord in
Landlord's reasonable discretion.

2.       Tenant Improvements.

         2.1      Tenant Improvements Defined. As used herein, "TENANT
IMPROVEMENTS" shall mean all improvements to the Building desired by Tenant of a
fixed and permanent nature, exclusive of the improvements described on Exhibit A
attached hereto ("LANDLORD'S IMPROVEMENTS"). Except as provided for herein,
other than Landlord's Improvements and providing the TI Allowance hereunder,
Landlord shall not have any obligation whatsoever with respect to finishing the
Premises for Tenant's use and occupancy. The Tenant Improvements may be built in
not more that two phases, each a "PHASE," the first of which shall be referred
to herein and in the Lease as "PHASE I" and the second of which shall be
referred to herein and in the Lease as "PHASE II." Phase I shall consist of not
less than one-half of the Premises.

         2.2      Tenant's Space Plans. Tenant may, until 24 months after the
Rent Commencement Date, prepare and submit for Landlord's review and approval
schematic drawings and outline specifications (the "DESIGN DRAWINGS") detailing
Tenant's requirements for the Phase I and the Phase II Tenant Improvements which
shall be consistent with the Permitted Use. Not more than 10 Business Days after
each such submission, Landlord shall deliver to Tenant Landlord's reasonable
written objections, questions or comments with regard to the Design Drawings so
submitted. Tenant shall cause the Design Drawings to be revised to address such
written comments and shall resubmit said drawings to Landlord for approval. Such
process shall continue until Landlord has approved the Design Drawings. If any
proposed work of improvement set forth on the Design Drawings or any logical
development of the Design Drawings has an adverse impact on the structure or
operational efficiency of the Building or portions of the Building lying outside
the Premises, all costs of mitigating such adverse impacts shall be paid from
the TI Fund.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 28]

<PAGE>

         2.3      Preliminary Plans. Following Landlord's approval of the Design
Drawings for Phase I or Phase II, Tenant shall prepare and submit for Landlord's
review and approval preliminary plans and specifications for Tenant's Work (the
"PRELIMINARY PLANS"). Landlord shall have the right to approve or disapprove the
Preliminary Plans, which approval shall not be unreasonably withheld or delayed,
provided, however, that except for matters which affecting on the Structure, as
defined below, and matters that do not comply with all applicable building and
land use laws, rules and regulations, Landlord may not disapprove any matter
that is consistent with the Design Drawings. "STRUCTURE" shall mean: (i)
structural portions of the Building including exterior walls, roof, foundation
or the core of the Building, (ii) the exterior of the Building, or (iii) any of
the Building systems, including, without limitation, elevator, plumbing, air
conditioning, heating electrical, security, life safety or power. Tenant shall
cause the Preliminary Plans to be revised to address such written comments and
shall resubmit said drawings to Landlord for approval. Such process shall
continue until Landlord has approved the Preliminary Plans. If Landlord fails to
give written notice of its approval or disapproval within 5 business days
following its receipt of the Preliminary Plans or any required modification or
amendment thereof, the same shall be deemed to have been approved by Landlord.
Tenant shall be solely responsible for ensuring that the Preliminary Plans
reflect Tenant's requirements for Tenant's Work.

         2.4      Final Plans and Specifications.

                  2.4.1    Following Landlord's approval of the Preliminary
         Plans, Tenant shall cause the Architect to prepare and deliver to
         Landlord for review: (i) construction plans, specifications and
         drawings for Tenant's Work ("CONSTRUCTION DRAWINGS"), and (ii) a
         detailed cost estimate for Tenant's Work broken down by trade (i.e.,
         mechanical, electrical, plumbing, etc.), unit prices for the items
         specified in the Construction Drawings and a project construction
         schedule in a format reasonably acceptable to both parties
         (collectively such items listed in clauses (i) and (ii) are referred to
         herein as the "CONSTRUCTION DATA"). Landlord shall have the right to
         approve or disapprove the Construction Drawings, which approval shall
         not be unreasonably withheld or delayed. Landlord may participate in
         all design meetings with Tenant, the Architect, Contractor and other
         design professional as appropriate in the course of the development of
         the Construction Data. Landlord shall deliver its approval or
         disapproval of the Construction Drawings to Tenant not later than 5
         business days after Landlord's receipt of same. If Landlord disapproves
         the Construction Drawings such disapproval shall be accompanied by
         detailed written comments setting forth the basis for such disapproval.
         Tenant and the Architect shall, within 5 business days after receipt of
         Landlord's disapproval of the Construction Drawings cause the
         Construction Drawings to be redrafted to address such issues, and shall
         resubmit them for Landlord's approval as described herein until
         Landlord approves the Construction Drawings. Tenant shall be solely
         responsible for ensuring that the Construction Drawings reflect
         Tenant's requirements for the Tenant Improvements.

                  2.4.2    Landlord shall have the right to disapprove the
         Construction Drawings which: (i) do not comply with all applicable
         building and land use laws, rules and regulations, (ii) in Landlord's
         reasonable opinion, adversely impact the Structure, or (iii) are not
         consistent with the Preliminary Plans.

                  2.4.3    No Tenant's Work may begin until final cost estimates
         for such Tenant's Work have been received and reasonably approved by
         Landlord, and any deposit required to be made by Tenant with Landlord
         in respect of costs in excess of the TI Allowance has been made.

3.       Performance of Tenant's Work.

         3.1      Commencement and Permitting of Tenant's Work. Following
completion of Landlord's Improvements to the extent required for Tenant to
commence and prosecute Tenant's Work without material interference, Tenant shall
commence construction of Tenant's Work upon obtaining a building permit
authorizing the construction of Tenant's Work (the "BUILDING PERMIT"), which
Building Permit shall be paid for out of the TI Fund (as defined in Section 5.4
below), and shall diligently prosecute such construction to Substantial
Completion. Landlord shall assist Tenant in obtaining the Building Permit.

             [100 Philips parkway/Memory Pharmaceuticals- Page 29]

<PAGE>

         3.2      Completion of Tenant's Work. Tenant shall substantially
complete or cause to be substantially completed Tenant's Work in a good and
workmanlike manner, in accordance with the Building Permit, subject to Minor
Variations and normal "punch list" items of a non-material nature which do not
interfere with the use of the Premises ("SUBSTANTIAL COMPLETION"). Upon the
Substantial Completion of Tenant's Work, Tenant shall require the Architect and
the general contractor to execute and deliver, for the benefit of Tenant and
Landlord, a Certificate of Substantial Completion in the form of the American
Institute of Architects document G704. For purposes of this Work Letter, "MINOR
VARIATIONS" shall mean any modifications reasonably required: (i) to comply with
all applicable Legal Requirements and/or to obtain or to comply with any
required permit (including the Building Permit); (ii) to comply with any request
by the Tenant for modifications to Tenant's Work; (iii) to comport with good
design, engineering, and construction practices which are not material; or (iv)
to make reasonable adjustments for field deviations or conditions encountered
during the construction of Tenant's Work.

         3.3      Construction Defects. Landlord shall have no obligation or
liability of any kind to remedy or cause any responsible contractor to remedy:
(i) any non-compliance of Tenant's Work with Code, (ii) any claim that Tenant's
Work was not completed substantially in accordance with the Construction
Drawings, or (iii) any other defect in Tenant's Work (collectively a
"CONSTRUCTION DEFECT"), other than to cooperate, at no cost to Landlord, with
Tenant should Tenant elect to pursue a claim against any such contractor,
provided that Tenant indemnifies and holds Landlord harmless from and against
any liability, loss, cost damage or expense in connection with any such claim.
Tenant shall be entitled to receive the benefit of all construction warranties
and manufacturer's equipment warranties relating to equipment installed in the
Premises.

         3.4      Commencement Date Delay. The Rent Commencement Date shall
occur on the earlier of the date Tenant's Work has been Substantially Completed
(the "COMPLETION DATE") or May 1, 2000, except to the extent that completion of
Tenant's Work has been actually delayed beyond May 1, 2000, by any one or more
of the following causes (a "LANDLORD DELAY"):

                  3.4.1    Landlord's Representative was not available to give
         or receive any Communication or to take any other action required to be
         taken by Landlord hereunder;

                  3.4.2    Landlord's delay in reviewing, revising or approving
         plans and specifications beyond the periods set forth herein; or

                  3.4.3    Landlord's delay in making payments for Tenant's Work
         which are properly documented and supported as hereinbelow described.

If Tenant claims that the Rent Commencement Date has been delayed for any of the
foregoing reasons, then Tenant shall cause the Architect to certify the number
of days of such Landlord Delay and the May 1 ,2000, date shall be extended, if
required, one day for each day of such Landlord Delay.

4.       Changes. If Tenant shall desire any change or series of related changes
to Tenant's Work the implementation of which is estimated to change the Budget,
as defined below, by $25,000 or more (whether increasing or decreasing the
Budget) ("CHANGES"), Tenant shall notify Landlord in writing in substantially
the same form as the AIA standard change order form (a "CHANGE REQUEST"), which
Change Request shall detail the nature and extent of any such Change. Such
Change Request must be signed by Tenant's Representative. Landlord shall approve
or disapprove such Change Request within 5 Business Days of receipt of such
Change Request; provided, however that Landlord shall only disapprove Change
Requests which: (i) do not comply with all applicable building and land use
laws, rules and regulations, or (ii) in Landlord's reasonable opinion, adversely
impact the Structure. Before proceeding with any such Change approved by
Landlord, Tenant shall submit to Landlord in writing, within 10 Business Days of
receipt of Landlord's approval of the Change Request (or such longer period of
time as is reasonably required depending on the extent of the Change Request),
an analysis of the additional cost or savings involved, including, without
limitation construction, material, architectural and engineering costs and shall
deposit with landlord, if applicable, any additional Excess Costs resulting from
such Change.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 30]

<PAGE>

5.       Costs.

         5.1      Budget For Tenant Improvements. Before the commencement of
construction of Tenant's Work, Landlord shall be provided a detailed breakdown,
by trade, of the costs incurred or which will be incurred, in connection with
the design and construction of the Tenant's Work (the "BUDGET"). The Budget
shall be based upon the Construction Drawings approved by Landlord and shall
include a payment to Landlord, of administrative rent equal ("ADMINISTRATIVE
RENT") to $50,000 for Phase I and $25,000 for Phase II for monitoring and
inspecting the construction of Tenant's Work including but not limited to the
review of a drawings, plans specifications, permits, budgets, change requests
and other such Tenant required submittal relating to this Work Letter, which sum
shall be payable from the TI Fund. Such Administrative Rent shall include,
without limitation, all out-of-pocket costs, expenses and fees incurred by or on
behalf of Landlord arising from, out of, or in connection with, such monitoring
of the construction of the Tenant's Work, and shall be payable out of the TI
Fund. If the Budget for either Phase is greater than the TI Fund (as defined
below) for such Phase, Tenant shall deposit with Landlord the difference, in
cash, prior to the commencement of construction of the Tenant Improvements, for
disbursement by Landlord as described in Section 5.4.

         5.2      TI Allowance. Landlord shall provide to Tenant a tenant
improvement TI Allowance ("TI Allowance") of not less than $20 and not more than
$200 (any increase above $20, shall be in an increment of $15.00 for the first
increase and thereafter in increments of $10, until the last increment, which
shall be an increment of $5) per rentable square foot of the Premises, not to
exceed a total TI Allowance for Phases I and II of $4,700,000. Before commencing
any Tenant's Work for Phase I or Phase II, Tenant shall notify Landlord how much
TI Allowance Tenant has elected to receive from Landlord for such Phase. Such
election shall be final and binding on Tenant, and may not thereafter be
modified without Landlord's consent, which may granted or withheld in Landlord's
sole and absolute discretion. The TI Allowance shall be disbursed by Landlord in
accordance with this Work Letter.

         5.3      Costs Includable in TI Fund. The TI Fund shall be used solely
for the payment of design and construction costs in connection with the
construction of the Tenant Improvements, including, without limitation, Tenant's
project management and regulatory consultants, the cost of preparing the Design
Drawings, the Preliminary Plans and the Construction Drawings, all costs set
forth in the Budget, including Landlord's Administrative Rent and the cost of
Changes, to the extent of the TI Fund. Notwithstanding anything to the contrary
contained herein, the TI Fund shall not be used to purchase any furniture,
personal property or other non-building system materials or equipment,
including, but not be limited to, biological safety cabinets and other
scientific equipment not incorporated into the Improvements.

         5.4      Excess Costs. It is understood and agreed that Landlord is
under no obligation to bear any portion of the cost of any of the Tenant
Improvements except to the extent of the TI Allowance. If at any time and from
time-to-time, the remaining Costs under the Budget for either Phase exceed the
remaining unexpended TI Fund for such Phase, Tenant shall deposit with Landlord,
as a condition precedent to Landlord's fund the cost of any further Tenant's
Work, one hundred percent (100%) of the then current Tenant Improvements Cost
for such Phase in excess of the remaining TI Fund for such Phase ("EXCESS
COSTS"). If Tenant fails to deposit, or is late in depositing, any Excess Costs
with Landlord, Landlord shall have all of the rights and remedies set forth in
the Lease for nonpayment of Rent (including, but not limited to, the right to
interest at the Default Rate and the right to assess a late charge), and for
purposes of any litigation instituted with regard to such amounts the same will
be considered Rent. Such Excess Costs, together with the portion of the TI
Allowance allocated to such Phase, is herein referred to as the "TI FUND". Funds
so deposited by Tenant shall be the first thereafter disbursed to pay the cost
of Tenant's Work. Notwithstanding anything to the contrary set forth in this
Section 5.4, Tenant shall be fully and solely liable for any costs of Tenant's
Work in excess of the TI Allowance allocated to either Phase. If upon
Substantial Completion of the Tenant Improvements and the payment of all sums
due in connection therewith there remains any undisbursed TI Fund with respect
to either Phase, Tenant shall be entitled to such undisbursed TI Fund to the
extent of any Excess Costs deposit Tenant has actually made with Landlord.

         5.5      Payment for Tenant's Work. Not more than once a month during
the performance of any of Tenant's Work for Phase I or Phase II, upon submission
of a disbursement request in the form of Landlord's standard draw package, which
shall include American Institute of Architects document G702 and G703, an

              [100 Philips Parkway/Memory Pharmaceuticals- Page 31]

<PAGE>

Architect's certificate as to the work done, a notarized certification from the
Contractor, and such invoices and lien waivers as Landlord shall require (the
"DRAW PACKAGE"), all in form and substance as Landlord shall reasonably require,
Landlord shall make disbursements to pay the then due costs of Tenant's Work as
shown in the approved Draw Package within 10 business days of receipt of the
complete Draw Package.

6.       Miscellaneous

         6.1      Consents. Whenever consent or approval of either party is
required under this Work Letter, that party shall not unreasonably withhold,
condition or delay such consent or approval, except as may be expressly set
forth herein to the contrary.

         6.2      Modification. No modification, waiver or amendment of this
Work Agreement or of any of its conditions or provisions shall be binding upon
Landlord or Tenant unless in writing signed by Landlord and Tenant.

         6.3      Counterparts. This Work Letter may be executed in any number
of counterparts but all counterparts taken together shall constitute a single
document.

         6.4      Governing Law. This Work Letter shall be governed by,
construed and enforced in accordance with the internal laws of the state in
which the Premises are located, without regard to choice of law principles of
such State.

         6.5      Time of the Essence. Time is of the essence of this Work
Agreement and of each and all provisions thereof.

         6.6      Default. Notwithstanding anything set forth herein or in the
Lease to the contrary, Landlord shall not have any obligation to perform any
work hereunder or to fund any portion of the TI Fund during any period Tenant is
in Default under the Lease.

         6.7      Severability. If any term or provision of this Work Letter is
declared invalid or unenforceable, the remainder of this Work Letter shall not
be affected by such determination and shall continue to be valid and
enforceable.

         6.8      Merger. All understanding and agreements, oral or written,
heretofore made between the parties hereto and relating to Landlord's Work are
merged in this Work Letter, which alone (but inclusive of provisions of the
Lease incorporated herein and the final approved constructions drawings and
specifications prepared pursuant hereto) fully and completely expresses the
agreement between Landlord and Tenant with regard to the matters set forth in
this Work Letter.

         6.9      Entire Agreement. This Work Letter is made as a part of and
pursuant to the Lease and, together with the Lease, constitutes the entire
agreement of the parties with respect to the subject matter hereof. This Work
Letter is subject to all of the terms and limitation set forth in the Lease, and
neither party shall have any rights or remedies under this Work Letter separate
and apart from their respective remedies pursuant to the Lease.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 32]

<PAGE>

         IN WITNESS WHEREOF, Landlord and Tenant have executed this Work Letter
to be effective on the date first above written.

TENANT:                           LANDLORD:

MEMORY PHARMACEUTICALS CORP.,     ARE -100 PHILLIPS PARKWAY, LLC,
a Delaware corporation            a Delaware limited liability company

By:/s/ Joanne Leonard             By: ALEXANDRIA REAL ESTATE EQUITIES, L.P., a
------------------------              corporation, general partner
Its: Vice President, CFO

                                      By:   /s/ Lynn Anne Shapiro
                                           ------------------------------
                                      Its:  LYNN ANNE SHAPIRO
                                            GENERAL COUNSEL

[NOTARY SEAL]

             [100 Philips Parkway/Memory Pharmaceuticals- Page 33]
<PAGE>

                                      100 Philips Parkway/Memory Pharmaceuticals

                            SCHEDULE A to Work Letter

                             Landlord's Improvements

Landlord shall perform all work as detailed on the construction drawings and
specification for the renovation of the Property as prepared by SNS Architects
and Engineers and as permitted by the City of Montvale, New Jersey pursuant to
the Construction Permit issued on April 12, 1999 under Permit Number 990124.

<PAGE>

                                    EXHIBIT D

                       ACKNOWLEDGMENT OF COMMENCEMENT DATE

         This ACKNOWLEDGMENT OF COMMENCEMENT DATE dated as of __________, ____,
is made by between ARE-100 PHILIPS PARKWAY, LLC, a Delaware limited liability
company ("LANDLORD"), and MEMORY PHARMACEUTICALS CORP., a Delaware corporation
("TENANT") and is attached to and made a part of the Lease dated June 4, 1999
(the "Lease"), by and between Landlord and Tenant. Any initially capitalized
terms used but not defined herein shall have the meanings given them in the
Lease.

         Landlord and Tenant hereby acknowledge and agree, for all purposes of
the Lease, that the Commencement Date of the Term of the Lease is of
_____________, _____.

         IN WITNESS WHEREOF, Landlord and Tenant have executed this
ACKNOWLEDGMENT OF COMMENCEMENT DATE to be effective on the date first above
written.

TENANT:                        LANDLORD:

MEMORY PHARMACEUTICALS CORP.,  ARE - 100 PHILLIPS PARKWAY, LLC.
a Delaware corporation         a Delaware limited liability company

                               By: ALEXANDRIA REAL ESTATE EQUITIES, L.P., a
By:_________________________       Delaware limited partnership, managing member
Its:________________________
                                   By: ARE-QRS CORP., a Maryland
                                       corporation, general partner

                                       By:______________________________________
                                       Its:_____________________________________

[NOTARY SEAL]

             [100 Philips Parkway/Memory Pharmaceuticals- Page 35]
<PAGE>

                                    EXHIBIT E

                              RULES AND REGULATIONS

1.       The sidewalk, entries, and driveways of the Project shall not be
         obstructed by Tenant, or its agents, or used by them for any purpose
         other than ingress and egress to and from the Premises.

2.       Tenant shall not place any objects, including antennas, outdoor
         furniture, etc., in the parking areas, landscaped areas or other areas
         outside of its Premises, or on the roof of the Project without
         Landlord's prior written consent, which shall not be unreasonably
         withheld or delayed.

3.       Tenant shall not disturb the occupants of the Project or adjoining
         buildings by the use of any radio or musical instrument or by the
         making of loud or improper noises.

4.       If Tenant desires telegraphic, telephonic or other electric connections
         in the Premises, Landlord or its agent will direct the electrician as
         to where and how the wires may be introduced; and, without such
         direction, no boring or cutting of wires will be permitted. Any such
         installation or connection shall be made at Tenant's expense.

5.       Tenant shall not install or operate any steam or gas engine or boiler,
         or other mechanical apparatus in the Premises, except for ordinary
         laboratory equipment used in connection with tenant's operations in the
         Premises and except as specifically approved in the Lease. The use of
         oil, gas or inflammable liquids for heating, lighting or any other
         purpose is expressly prohibited. Explosives or other articles deemed
         extra hazardous shall not be brought into the Project.

6.       Parking any type of recreational vehicles is specifically prohibited on
         or about the Project. Except for the overnight parking of operative
         vehicles, no vehicle of any type shall be stored in the parking areas
         at any time. In the event that a vehicle is disabled, it shall be
         removed within 48 hours. There shall be no "For Sale" or other
         advertising signs on or about any parked vehicle. All vehicles shall be
         parked in the designated parking areas in conformity with all signs and
         other markings. All parking will be open parking, and no reserved
         parking, numbering or lettering of individual spaces will be permitted
         except as specified by Landlord.

7.       Tenant shall maintain the Premises free from rodents (other than
         experimental subjects), insects and other pests.

8.       Landlord reserves the right to exclude or expel from the Project any
         person who, in the judgment of Landlord, is intoxicated or under the
         influence of liquor or drugs or who shall in any manner do any act in
         violation of the Rules and Regulations of the Project.

9.       Tenant shall not cause any unnecessary labor by reason of Tenant's
         carelessness or indifference in the preservation of good order and
         cleanliness. Landlord shall not be responsible to Tenant for any loss
         of property on the Premises, however occurring, or for any damage done
         to the effects of Tenant by the janitors or any other employee or
         person.

10.      Tenant shall give Landlord prompt notice of any defects in the water,
         lawn sprinkler, sewage, gas pipes, electrical lights and fixtures,
         heating apparatus, or any other service equipment affecting the
         Premises.

11.      Tenant shall not permit storage outside the Premises, including without
         limitation, outside storage of trucks and other vehicles, or dumping of
         waste or refuse or permit any harmful materials to be placed in any
         drainage system or sanitary system in or about the Premises.

12.      All moveable trash receptacles provided by the trash disposal firm for
         the Premises must be kept in the trash enclosure areas, if any,
         provided for that purpose.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 36]
<PAGE>

13.      No auction, public or private, will be permitted on the Premises or the
         Project.

14.      No awnings shall be placed over the windows in the Premises except with
         the prior written consent of Landlord.

15.      The Premises shall not be used for lodging, hospitality or restaurant
         purposes (other than in connection with an employee cafeteria) or for
         any immoral or illegal purposes or for any purpose other than that
         specified in the Lease. No gaming devices shall be operated in the
         Premises.

16.      Tenant assumes full responsibility for protecting the Premises from
         theft, robbery and pilferage.

17.      Tenant shall not install or operate on the Premises any machinery or
         mechanical devices of a nature not directly related to Tenant's
         ordinary use of the Premises and shall keep all such machinery free of
         vibration, noise and air waves which may be transmitted beyond the
         Premises.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 37]
<PAGE>

                                    EXHIBIT G

                          FORM OF ESTOPPEL CERTIFICATE

         THIS TENANT ESTOPPEL CERTIFICATE ("CERTIFICATE"), dated as
of___________________________, 19__, is executed by MEMORY PHARMACEUTICALS
CORP., a Delaware corporation, as TENANT ("TENANT") in favor of [______________,
together with its nominees, designees and assigns (collectively, "BUYER"),
and/or in favor of _________________, together with its nominees, designees and
assigns (collectively, "LENDER").]

                                    RECITALS

                                    [ALT 1]

         A. Buyer and ARE-100 Philips Parkway, LLC, a Delaware limited liability
company ("LANDLORD"), have entered into that certain Purchase and Sale Agreement
and Joint Escrow Instructions, dated as of_____________________, 19___(the
"PURCHASE AGREEMENT"), whereby Buyer has agreed to purchase, among other things,
the improved real property located in the City of Montvale, County of
________________, State of New Jersey, more particularly described on Exhibit
"1" attached to the Purchase Agreement (the "BUILDING").

         B. Tenant and Landlord have entered into that certain Lease Agreement,
dated as of June 4, 1999 (together with all amendments, modifications,
supplements, guarantees and restatements thereof, the "LEASE"), for a portion of
the Building.

         C. Pursuant to the Lease, Tenant has agreed that upon the request of
Landlord, Tenant would execute and deliver an estoppel certificate certifying
the status of the Lease.

         D. In connection with the Purchase Agreement, Landlord has requested
that Tenant execute this Certificate with an understanding that Lender will rely
on the representations and agreements below in granting to Buyer a loan.

                                     [ALT 2]

         A. Tenant and Landlord have entered into that certain Lease Agreement,
dated as of June 4, 1999 (together with all amendments, modifications,
supplements, guarantees and restatements thereof, the "LEASE"), for a portion of
the Building.

         B. Pursuant to the Lease, Tenant has agreed that upon the request of
Landlord, Tenant would execute and deliver an estoppel certificate certifying
the status of the Lease.

         C. In connection with a refinancing of the Building, Landlord has
requested that Tenant execute this Certificate with an understanding that Lender
will rely on the representations and agreements below in granting to Landlord a
loan.

         NOW, THEREFORE, Tenant certifies, warrants, and represents to [Buyer
and/or Lender] as follows:

         SECTION 1. LEASE. Attached hereto as Exhibit "1" is a true, correct and
complete copy of the Lease, including the following amendments, modifications,
supplements, guarantees and restatements thereof, which together represent all
of the amendments, modifications, supplements, guarantees and restatements
thereof:

--------------------------------------------------------------------------------
_______________________________________________________________________________.
(If none, please state "None.")

         SECTION 2. PREMISES. Pursuant to the Lease, Tenant leases those certain
Premises consisting of approximately_______________________ (_________)
rentable square feet within the Building, as more particularly described in the
Lease. In addition, pursuant to the terms of the Lease, Tenant has the
non-exclusive right to use________designated parking spaces on a lot near the
Building during the term of the Lease.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 38]
<PAGE>

         SECTION 3. FULL FORCE OF LEASE. The Lease has been duly authorized,
executed and delivered by Tenant, is in full force and effect has not been
terminated and constitutes a legally valid instrument, binding and enforceable
against Tenant in accordance with its terms, subject only to applicable
limitations imposed by law.

         SECTION 4. COMPLETE AGREEMENT. The Lease constitutes the complete
agreement between Landlord and Tenant for the Premises and the Building, except
as modified by the Lease amendments noted above (if any), has not been modified,
altered or amended.

         [SECTION 5. ACCEPTANCE OF PREMISES. Tenant has accepted possession and
is currently occupying the entire Premises.]

         SECTION 6. LEASE TERM. The Term Commencement Date of the Lease is
_________________, _________ and ends on_________________________, ________
subject to the following options to extend: two (2) five (5) year extension
periods to be exercised by Tenant in the manner as set forth in Section 42 of
the Lease.

         SECTION 7. PURCHASE RIGHTS. Tenant has no option, right of first
refusal, right of first offer, or other right to acquire or purchase all or any
portion of the Premises or all or any portion of, or ownership interest in, the
Building.

         SECTION 8. RIGHTS OF TENANT. Except as expressly stated in this
Certificate, Tenant:

                  (a) has no other right to renew or extend the Term of the
         Lease;

                  (b) has no right, title, or interest in the Premises or the
         Building, other than as Tenant under the Lease.

         SECTION 9. RENT.

                  (a) The obligation to pay Rent for the entire Premises
         commenced on___________________, 2000. The Rent under the Lease is
         current, and Tenant is not in default in the performance of any of its
         obligations under the Lease.

                  (b) Tenant is currently paying monthly Rental Installments
         under the Lease in the amount of ____________________Dollars
         ($_______________) per month. Tenant has not received and is not,
         presently, entitled to any abatement, refunds, rebates, concessions or
         forgiveness of Rent or other charges, free Rent, partial Rent, or
         credits, offsets or reductions in Rent, except as follows:
         _____________________________ __________(If none, please state "None.")

                  (c) Tenant's estimated share of Operating Expenses for the
         Premises is____________________ percent ( %) and is currently being
         paid at the rate of__________________Dollars ($____________) per month.

                  (d) There are no existing defenses or offsets against Rent due
         or to become due under the terms of the Lease, and there presently is
         no Default or, to the actual knowledge of Tenant, other wrongful act or
         omission by Landlord under the Lease or otherwise in connection with
         Tenant's occupancy of the Premises, nor is there a state of facts which
         with the passage of time or the giving of notice or both could ripen
         into a Default on the part of Tenant, or to the actual knowledge of
         Tenant, could ripen into a Default on the part of Landlord under the
         Lease, except, with respect to any of the foregoing, as
         follows:_____________________ _______________________. (If none, please
         state "None.")

         SECTION 10. SECURITY DEPOSIT. The amount of Tenant's security deposit
held by Landlord under the Lease is _____ ___________________________Dollars
($____________).

         SECTION 11. PREPAID RENT. The amount of prepaid Rent, separate from the
security deposit, is ________________________ Dollars ($_______________),
covering the period from___________________________________ to _________.

             [100 Philips Parkway/Memory Pharmaceuticals- Page 39]
<PAGE>

         SECTION 12. INSURANCE. All insurance, if any, required to be maintained
by Tenant under the Lease is presently in effect.

         SECTION 13. PENDING ACTIONS. To the actual knowledge of Tenant, there
is not pending or threatened against or contemplated by the Tenant, any petition
in bankruptcy, whether voluntary or otherwise, any assignment for the benefit of
creditors, or any petition seeking reorganization or arrangement under the
federal bankruptcy laws of those of any state.

         SECTION 14. TENANT IMPROVEMENTS. As of the date of this Certificate, to
the Tenant's actual knowledge: Landlord has performed all obligations required
of Landlord pursuant to the Lease; no offsets, counterclaims, or defenses of
Tenant under the Lease exist against Landlord; and no events have occurred that,
with the passage of time or the giving of notice, would constitute a basis for
offsets, counterclaims, or defenses against Landlord, except as
follows:____________________________________________________. (If none, please
state "none.")

         SECTION 15. ASSIGNMENTS BY LANDLORD. Tenant has received no notice of
any assignment, hypothecation or pledge of the Lease or rentals under the Lease
by Landlord, except as follows:_______________________________________________
"None.")

         [ALT 1] Tenant hereby consents to an assignment of the Lease and Rent
to be executed by Landlord to Lender in connection with the Loan and
acknowledges that said assignment does not violate the provisions of the Lease.
Tenant acknowledges that the interest of the Landlord under the Lease is to be
assigned to Lender solely as security for the purposes specified in said
assignment and Lender shall have no duty, liability of obligation whatsoever
under the Lease or any extension or renewal thereof, either by virtue of said
assignment or by any subsequent receipt or collection of Rent thereunder; unless
Lender shall specifically undertake such liability in writing except as provided
for in a writing binding on Lender. Tenant agrees that upon receipt of a written
notice from Lender of a default by Landlord under the Loan. Tenant will
thereafter pay Rent to Lender in accordance with the terms of the Lease.

         [ALT 2] Tenant hereby consents to an assignment of the Lease and Rents
to be executed by Landlord to Buyer in connection with the sale of the Building
to Buyer and the Buyer's loan and acknowledges that said assignment does not
violate the provisions of the Lease. Tenant acknowledges that he interest of the
Buyer as Landlord under the Lease is to be assigned to Lender solely as security
for the purposes specified in said assignment and Lender shall have no duty,
liability or obligation whatsoever under the Lease or any extension or renewal
thereof, either by virtue of said assignment or by any subsequent receipt or
collection of Rents thereunder, unless Lender shall specifically undertake such
liability in writing except as provided for in a writing binding on Buyer.
Tenant agrees that upon receipt of a written notice from Lender of a default by
Buyer under the Loan. Tenant will thereafter pay Rent to Lender in accordance
with the terms of the Lease.

         SECTION 16. ASSIGNMENTS BY TENANT. Except as expressly set forth in the
Lease, Tenant has not sublet or assigned the Premises or the Lease or any
portion thereof to any sublessee or assignee. If Tenant has sublet or assigned
all or any portion of the Premises in the manner proscribed in the Lease the
assignees or subtenants are as follows:___________________________________. The
address for notices to be sent to Tenant is as set forth in the Lease or is as
follows:_____________________________________________________________.

         SECTION 17. ENVIRONMENTAL MATTERS. The operation and use of the
Premises does not involve the generation, treatment, storage, disposal or
release into the environment of any hazardous materials, regulated materials
and/or solid waste, except those used in the ordinary course of operating a
research laboratory or otherwise used in accordance with all applicable laws.

         SECTION 18. SUCCESSION OF INTEREST. Tenant agrees that, in the event
[Buyer and/or Lender] succeeds to interest of Landlord under the Lease:

             [100 Philips Parkway/Memory Pharmaceuticals- Page 40]
<PAGE>

                  (a)      [Buyer and/or Lender] shall not be liable for any act
         or omission of any prior landlord (including Landlord) except as
         provided for in a writing binding on [Buyer and/or Landlord];

                  (b)      [Buyer and/or Lender] shall not be liable for the
         return of any security deposit [unless the security deposit is
         delivered to Buyer and/or Lender];

                  (c)      [Buyer and/or Lender] shall not be bound by any Rent
         or Additional Rent which Tenant might have prepaid under the Lease for
         more than the current month;

                  (d)      Lender shall not be bound by any amendments or
         modifications of the Lease made after the date hereof without prior
         consent of Lender and Buyer shall not be bound by any amendments or
         modifications of the Lease not disclosed by Tenant herein;

                  (e)      Lender shall not be subject to any offsets or
         defenses which Tenant might have against any prior landlord (including
         Landlord); or

                  (f)      Lender shall not be liable under the Lease to Tenant
         for the performance of Landlord's obligations under the Lease beyond
         Lender's interest in the Building including the rents and profits to be
         derived therefrom after the date of any Landlord default under the
         Lease.

         SECTION 19. NOTICE OF DEFAULT. Tenant agrees to give Lender a copy of
any notice of default under the Lease served upon Landlord at the same time as
such notice is given to the Landlord. Tenant further agrees that if Landlord
shall fail to cure such default within the applicable grace period, if any,
provided in the Lease, then Lender shall have an additional thirty (30) days
within which to cure such default, or if such default cannot be cured within
such thirty (30) day period, such thirty (30) day period shall be extended so
long as Lender has commenced and is diligently pursuing the remedies necessary
to cure such default (including, but not limited to, commencement of foreclosure
proceedings, if necessary to effect (such cure), in which event the Lease shall
not be terminated while such remedies are being pursued.

         SECTION 20. NOTIFICATION BY TENANT. From the date of this Certificate
and continuing for 60 days after the date hereof, Tenant agrees to promptly
notify [Buyer and/or Lender], in writing by registered or certified mail, return
receipt requested, at the following addresses, on the occurrence of any event or
the discovery of any fact that would make any representation contained in this
Certificate inaccurate:

         If To Buyer:     _________________________________________
                          _________________________________________
                          _________________________________________

         With A Copy To:  _________________________________________
                          _________________________________________
                          _________________________________________

         If To Lender:    _________________________________________
                          _________________________________________
                          _________________________________________

         Tenant makes this Certificate with the knowledge that it will be relied
upon by Buyer in agreeing to purchase the Building and by Lender in making a
loan secured by the Building. Tenant's obligations under the last sentence of
Section 15 of this Estoppel Certificate are contingent upon Landlord's consent
to such sentence, which consent shall be evidenced by Landlord's execution
hereof in the space provided below.

         Tenant has executed this Certificate as of the date first written above
by the person named below, who is duly authorized to do so.

                                     TENANT

              [100 Philips Parkway/Memory Pharmaceuticals- Page 41]
<PAGE>

                                              MEMORY PHARMACEUTICALS CORP.,
                                              a Delaware corporation

                                              By:    ___________________________
                                              Name:  ___________________________
                                              Its:   ___________________________

         Landlord hereby consents to the last sentence of Section 15 of this
Estoppel Certificate.

                                              [LANDLORD]

                                              By:    ___________________________
                                              Name:  ___________________________
                                              Its:   ___________________________

              [100 Philips Parkway/Memory Pharmaceuticals- Page 42]
<PAGE>

                                    EXHIBIT H

                       SUBORDINATION, NON-DISTURBANCE AND
                              ATTORNMENT AGREEMENT

         THIS SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT is made
and entered into as of this____day of______________________,_____ ("AGREEMENT"),
by and between ARE-100 PHILIPS PARKWAY, LLC, a Delaware limited liability
company, together with its nominees, designees and assigns (collectively,
"LANDLORD"), MEMORY PHARMACEUTICALS CORP., a Delaware corporation ("TENANT"),
and _____________________________("MORTGAGEE").

         WHEREAS, Mortgagee is making a loan to Landlord and others evidenced by
a certain promissory note ("NOTE"), and secured by, among other things, a deed
of trust/mortgage to be recorded prior hereto in the public records of the City
of ___________, County of __________, State of New Jersey ("MORTGAGE")
constituting a lien upon the real property described in Exhibit A hereto (the
"BUILDING"); and

         WHEREAS, Landlord and Tenant have entered into a Lease Agreement, dated
as of June 4, 1999 ("LEASE"), for certain Premises in the Building located at
100 Philips Parkway, Montvale, New Jersey, containing approximately 32,000
rentable square feet (hereinafter referred to as "PREMISES"); and

         WHEREAS, Mortgagee wishes to obtain from Tenant certain assurances that
Tenant will attorn to Mortgagee in the event of a foreclosure by Mortgagee or
the exercise of other rights under the Mortgage; and

         WHEREAS, Tenant wishes to obtain from Mortgagee certain assurances that
Tenant's possession of the Premises will not, subject to the terms and
conditions of this Agreement, be disturbed by reason of a foreclosure of the
lien of the Mortgage on the Building; and

         WHEREAS, Tenant and Mortgagee are both willing to provide such
assurances to each other upon and subject to the terms and conditions of this
Agreement.

         NOW, THEREFORE, in consideration of the above, the mutual promises
hereinafter set forth, and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the parties hereto mutually
agree as follows:

         1.       AFFIRMATION. Tenant hereby agrees that the Lease now
is and shall be subject and subordinate in all respects to the Mortgage and to
all renewals, modifications and extensions thereof until such time that the
Mortgage is released, satisfied or otherwise discharged, subject to the terms
and conditions of this Agreement. Landlord and Tenant hereby affirm that the
Lease is in full force and effect and that the Lease has not been modified or
amended except as follows:___________________________________________________.
Mortgagee hereby confirms that it is the holder of the Note and the beneficiary
of the Mortgage and has full power and authority to enter into this Agreement.

         2.       ATTORNMENT AND NON-DISTURBANCE. So long as Tenant is not in
Default under the Lease, as would entitle the Landlord to terminate the Lease or
would cause the termination of Tenant's possession of the Premises, Mortgagee
will not join Tenant as a party defendant in any action or proceeding for the
purpose of terminating Tenant's interest and estate under the Lease because of
any default under the Mortgage. Mortgagee further agrees with Tenant that in the
event the interest of Landlord shall be acquired by Mortgagee or in the event
Mortgagee comes into possession of or acquires title to the Building by reason
of foreclosure or foreclosure sale or the enforcement of the Mortgage or the
Note or other obligation secured thereby or by a conveyance in lieu thereof, or
as a result of any other means then:

                  (a)      subject to the provisions of this Agreement, Tenant's
         occupancy and possession of the Premises and Tenant's rights and
         privileges under the Lease or any extensions, modifications or renewals
         thereof or substitutions therefor (in accordance with the Lease and the
         Mortgage) shall not

              [100 Philips Parkway/Memory Pharmaceuticals- Page 43]
<PAGE>

         be disturbed, diminished or interfered with by Mortgagee during the
         Term of the Lease (including any extensions or renewals thereof
         provided for in the Lease); and

                  (b)      the Lease shall continue in full force and effect and
         shall not be terminated except in accordance with the terms of the
         Lease.

         Tenant shall be bound to Mortgagee under all of the terms, covenants
and conditions of the Lease for the balance of the term thereof remaining (and
any extensions or renewals thereof which may be effected in accordance with any
option contained in the Lease) with the same force and effect as if Mortgagee
were the landlord under the Lease, and Tenant does hereby agree to attorn to
Mortgagee as its landlord, said attornment to be effective and self-operative
without the execution of any other instruments on the part of either party
hereto immediately upon Mortgagee's succeeding to the interest of Landlord under
the Lease. Upon request of Lender or such Purchaser (as hereinafter defined),
Tenant shall execute and deliver to Lender or such Purchaser an agreement
reaffirming such attornment. Tenant hereby agrees that any right of first
refusal or right of first offer to purchase the Building which Tenant may have
pursuant to the terms of the Lease shall not be applicable to Mortgagee's or any
Purchaser's acquisition of the Building by foreclosure, deed in lieu of
foreclosure, other transaction related thereto or in substitution thereof,
trustee sale or other similar statutory conveyance.

         In the event that the Mortgage is foreclosed and any party
("PURCHASER") other than Mortgagee purchases the Building and succeeds to the
interest of Landlord under the Lease, Tenant shall likewise be bound to
Purchaser and Tenant hereby covenants and agrees to attorn to Purchaser in
accordance with all of the provisions of this Agreement provided that Purchaser
shall transmit to Tenant a written document in recordable form, whereby
Purchaser covenants and agrees to recognize Tenant as its lessee under the Lease
and agrees to be directly bound to Tenant for the performance and observance of
all the terms and conditions of the Lease required to be performed or observed
by Landlord thereunder, subject to and in accordance with the terms of this
Agreement.

          Mortgagee agrees that if Mortgagee shall succeed to the interest of
 Landlord under the Lease as above provided Mortgagee shall be bound to Tenant
 under all of the terms, covenants, and conditions of this Lease and Tenant
 shall, from and after Mortgagee's succession to the interest of Landlord under
 the Lease, have the same remedies against Mortgagee that Tenant might have had
 under the Lease against Landlord if Mortgagee had not succeeded to the
 interest of Landlord; provided, however, that Mortgagee (and Purchaser, as the
 case may be) shall not be:

                  (a)      liable for any act or omission of any prior lessor
         (including Landlord) occurring prior to the date that Mortgagee or
         Purchaser acquired title to the Premises except for lessor's obligation
         to build out the Initial Premises if such transfer occurs before the
         Rent Commencement Date; or

                  (b)      subject to any offsets, counterclaims or defenses
         which Tenant might have against any prior lessor (including Landlord);
         or

                  (c)      bound by any previous payment of Rent or Additional
         Rent for a period greater than one (1) month unless such prepayment
         shall have been consented to in writing by Mortgagee or Purchaser or
         has been delivered to Mortgagee or Purchaser; or

                  (d)      bound by any amendment or modification of the Lease
         made after the date hereof but prior to the date Mortgagee or Purchaser
         succeeds to the interest of Landlord without Mortgagee's or Purchaser's
         written consent; or

                  (e)      liable to Tenant for any previous loss of business or
         any other indirect or consequential damages from whatever cause;
         provided, however, no inference shall be drawn from this clause (e)
         that Tenant would otherwise be entitled (or not entitled) to recover
         for loss of business or any other indirect or consequential damages; or

              [100 Philips Parkway/Memory Pharmaceuticals- Page 44]
<PAGE>

                  (f)      liable for the return of any security deposit unless
         such deposit has been paid over to the Mortgagee or Purchaser.

The foregoing shall not be construed to modify or limit any right Tenant may
have at law or in equity against Landlord or any other prior owner of the
Building.

         3.       NOTICES. All notices required or permitted to be given
pursuant to this Agreement shall be in writing and shall be sent postage
prepaid, by certified mail, return receipt requested or other nationally
utilized overnight delivery service. All notices shall be deemed delivered when
received or refused. Rejection or other refusal to accept or inability to
deliver because of changed address of which no notice has been given shall
constitute receipt of the notice, demand or request sent. Any such notice if
given to Tenant shall be addressed as follows:

                                    _________________________________________
                                    _________________________________________
                                    _________________________________________

         if given to Landlord shall be addressed as follows:

                                    ARE-100 Philips Parkway, LLC
                                    150 S. Los Robles Ave., Suite 250
                                    Pasadena, California 91101
                                    Attention: Corporate Secretary

         with a copy to:

                                    Alexandria Real Estate Equities, Inc.
                                    135 N. Los Robles Ave., Suite 250
                                    Pasadena, California 91101
                                    Attention: General Counsel

         if given to Mortgagee shall be addressed as follows:

                                    _________________________________________
                                    _________________________________________
                                    _________________________________________

         4.       SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon
and inure to the benefit of the parties hereto and their respective successors
and assigns. The words "foreclosure" and "foreclosure sale" as used herein shall
be deemed to also include the acquisition of Landlord's estate in the Building
by voluntary deed, assignment or other conveyance or transfer in lieu of
foreclosure.

         5.       MODIFICATIONS TO LEASE. Tenant shall not modify or amend the
Lease or terminate the same [ADD IF SNDA REQUESTED BEFORE COMMENCEMENT DATE -
AFTER THE DELIVERY OF THE PREMISES] without Mortgagee's prior written consent.
If Mortgagee fails to provide Tenant with a written approval of the proposed
modification, amendment or termination within ten (10) business days after
notice to Mortgagee of such proposal, then Mortgagee shall be deemed to have
rejected such proposal.

         6.       ADDITIONAL AGREEMENTS. Tenant agrees that:

                  (a)      it shall give Mortgagee copies of all notices of
         default and requests for approval or consent by Landlord that Tenant
         gives to Landlord pursuant to the Lease in the same manner as they are
         given to Landlord and no such notice of default shall be deemed to be
         effective with respect to Mortgagee's rights hereunder until a copy is
         given to Mortgagee;

              [100 Philips Parkway/Memory Pharmaceuticals- Page 45]
<PAGE>

                  (b)      in all provisions of the Lease where Landlord is
         indemnified, the reference to Landlord as an indemnitee shall be deemed
         to include Mortgagee and any Purchaser and, to the extent provided for
         in the Lease, such agreement of indemnification shall survive the
         repayment of the loan secured by the Mortgage and, to the extent
         provided in the Lease, the expiration or termination of the Lease;

                  (c)      Tenant shall name Mortgagee and any Purchaser, from
         and after the date of such purchase, as additional insureds and loss
         payees, as applicable and appropriate, on all insurance policies
         required by the Lease; and

                  (d)      this Agreement satisfies any condition or requirement
         in the Lease relating to the granting of a non-disturbance agreement by
         Mortgagee, and in the event that there are inconsistencies between the
         terms and provisions of this Agreement and the terms and provisions of
         the Lease dealing with non-disturbance by Mortgagee, the terms and
         provisions hereof shall be controlling; and

                  (e)      Mortgagee shall have no liability under the Lease
         until Mortgagee succeeds to the rights of the Landlord under the Lease,
         and then only during such period as Mortgagee is the Landlord. At all
         times during which Mortgagee is liable under the Lease, Mortgagee's
         liability shall be limited to Mortgagee's interest in the Building
         including the rents and profits to be derived therefrom after the date
         of any Landlord default under the Lease.

         7.       MORTGAGEE CURE RIGHTS. In the event of any default on the part
of Landlord, Tenant will give notice by registered or certified mail to
Mortgagee. Mortgagee shall have thirty (30) days from the expiration of
Landlord's applicable cure period to cure the default if the default can be
fully cured by the payment of a specific and liquidated amount of money. If the
default cannot be fully cured by the payment of a specific and liquidated amount
of money and possession is reasonably required to cure the default, and unless
Tenant shall have provided all access necessary to affect a cure, Mortgagee
shall promptly commence taking steps to obtain possession of the Premises by
foreclosure or the judicial appointment of a receiver after receipt of Tenant's
written notice of the default, and shall thereafter diligently continue to
attempt to cure the default within the minimum period of time reasonably
required under the circumstances to achieve a cure. The Lease shall not be
terminated (i) while such remedies are being diligently pursued or (ii) based
upon a default which is personal to Landlord and therefore not susceptible to
cure by Mortgagee or which requires possession of the Premises to cure.
Mortgagee shall in no event be obligated to cure any such default by Landlord
unless it forecloses. Nothing in this Section 7 shall affect any of Tenant's
termination rights under the Lease due to casualty or condemnation.

         8.       DIRECTION TO PAY. Landlord hereby directs Tenant and Tenant
agrees to make all payments of amounts owed by Tenant under the Lease directly
to Mortgagee from and after receipt by Tenant of notice from Mortgagee directing
Tenant to make such payments to Mortgagee. (As between Landlord and Mortgagee,
the foregoing provision shall not be construed to modify any rights of Landlord
under or any provisions of the Mortgage or any other instrument securing the
Note).

         9.       CONDITIONAL ASSIGNMENT. With reference to any assignment by
Landlord of Landlord's interest in the Lease, or the Rent payable thereunder,
conditional in nature or otherwise, which assignment is made to Mortgagee,
Tenant agrees that the execution thereof by Landlord, and the acceptance thereof
by Mortgagee shall never be treated as an assumption by Mortgagee of any of the
obligations of Landlord under the Lease unless and until Mortgagee shall have
succeeded to the interest of Landlord. The foregoing sentence shall not affect
any of Tenant's rights against Landlord under the Lease.

              [100 Philips Parkway/Memory Pharmaceuticals- Page 46]
<PAGE>

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be properly
executed by their duly authorized representatives as of the date first above
written.

                                    LANDLORD:
                                    _________________________________________

                                    TENANT:
                                    _________________________________________

                                    MORTGAGEE:
                                    _________________________________________

              [100 Philips Parkway/Memory Pharmaceuticals- Page 47]<PAGE>

                                                                    EXHIBIT 10.5

                            FIRST AMENDMENT TO LEASE

         This First Amendment to Lease ("FIRST AMENDMENT") is made as of
February 4, 2000, by and among ARE - 100 PHILIPS PARKWAY, LLC, a Delaware
limited liability company ("LANDLORD"), and MEMORY PHARMACEUTICALS CORP., a
Delaware corporation ("TENANT")

                                    RECITALS

         A. Landlord is the landlord and Tenant is the tenant under a Lease
dated as of June 4, 1999 as amended by letter agreement dated June 16, 1999,
between Landlord and Tenant (collectively the "LEASE"), under which Tenant
leases approximately 32,000 rentable square feet of space in the building
commonly known as 100 Philips Parkway, Montvale, New Jersey. Capitalized terms
used herein without definition shall have the meanings defined for such terms in
the Lease.

         B. Landlord and Tenant desire to amend the Lease to modify the
description of Landlord Work, the amount and allocation between Phase I and
Phase II of the TI Allowance provided by Landlord, to delay the Rent
Commencement Date by one month and to address other matters which have arisen
since the execution of the Lease.

                                    AGREEMENT

         Now, therefore, the parties hereto agree that the Lease is hereby
amended as follows:

1.       APPROVALS.

         (a)      Landlord hereby approves The Hillier Group as Tenant's
architect (the "ARCHITECT"). Subject to receipt of and Landlord's reasonable
satisfaction with a payment and performance bond from a surety with a Best's
Rating of A+ or higher, or equivalent, with respect to the work to be done by
McHugh, DiVicent & Alessi, Inc. ("MDA"). Landlord will approve MDA as Tenant's
general contractor ("CONTRACTOR"). Tenant shall deliver or cause MDA to deliver
such payment and performance bond before the commencement of any work by or on
behalf of Tenant in the Premises. All other engineering consultants, architects,
designers and subcontractors responsible for construction of Tenant's Work shall
be selected by Tenant, and approved by Landlord in Landlord's reasonable
discretion as provided in the Work Letter.

         (b)      Landlord hereby approves the design layout described in the
drawings dated as of January 10, 2000, prepared by the Architect (the "LAYOUT").
Upon submission of Design Drawings complying with the requirements of Section
2.2 of the Work Letter, Landlord shall not disapprove any matter shown in such
Design Drawings which are consistent with the Layout.

2.       MECHANICAL ROOM. Subject to receipt and review of proposed plans and
specifications for any portion of Tenant's HVAC system proposed to be located in
the common area mechanical room located on the ground floor of the Project (the
"COMMON AREA MECHANICAL ROOM") and provided that such proposed use of the Common
Area Mechanical Room does not materially interfere with the maintenance and
operation of the Project, in Landlord's sole discretion, Tenant may locate
certain mechanical portions of its HVAC system in such Common Area Mechanical
Room; provided

                                       1

<PAGE>

however that no existing machinery, equipment or duct work shall be relocated,
ingress and egress to such Common Area Mechanical Room and access to the
existing machinery, equipment and duct work shall not be blocked or in any way
impaired, and not more than 70% of the ground floor of the Common Area
Mechanical Room nor 50% of the combined ground floor and mezzanine floor of the
Common Area Mechanical Room shall be used by Tenant. Landlord agrees that Tenant
shall not be required to pay any additional rent as a result of any such use of
the Common Area Mechanical Room for such HVAC equipment. Tenant's access to the
Common Area Mechanical Room may be restricted in Landlord's reasonable
discretion. Upon no less than one business day's prior notice from Tenant to
Landlord, which notice may be made by telephone, facsimile or electronic mail,
Tenant may have reasonable access to the Common Area Mechanical Room as may be
required for the installation, maintenance and repair of such system.

3.       TI ALLOWANCE. Section 4(a) of the Lease is hereby amended by deleting
the phrase "up to a maximum increase of $180 per square foot of Rentable Area of
the Premises," replacing the figure $4,700,000 with the figure $4,950,000,
deleting the phrase "and not to exceed a TI Allowance of $3,500,000 for Phase I
of the Premises" from the first sentence thereof and deleting the last row of
the chart set forth therein and adding the following rows to such chart:

<TABLE>
<CAPTION>
    TI Allowance            Increase in Base Rent         Initial Base Rent
    ------------            ---------------------         -----------------
<S>                         <C>                           <C>
      $205.00                       $1.40                     $37.30/RSF
Each $10 thereafter                 $1.40
</TABLE>

The entire $4,950,000 TI Allowance may be drawn down by Tenant in connection
with Phase I and the entire $75,000 Administrative Rent described in Section 5.1
of the Work Letter shall be paid in connection with Tenant's Work for Phase I.
Any portion of the TI Allowance not used by Tenant in connection with Phase I
may be drawn down by Tenant in connection with Phase II and there shall be no
Administrative Rent charged by Landlord in connection with Tenant's Work for
Phase II.

4.       RENT COMMENCEMENT DATES. The second paragraph of Section 2 of the Lease
is hereby amended and restated as follows:

                  The "RENT COMMENCEMENT DATE" shall be earliest of: (i) the
         date Tenant's Work for Phase I is Substantially Complete, and (ii) June
         1, 2000. On the Rent Commencement Date, Tenant shall pay Base Rent for
         the entire Premises. Such Rent shall be calculated for Phase I of the
         Premises on the basis of the actual TI Allowance provided by Landlord
         to Tenant for Phase I as set forth in Section 4(a) below, and shall be
         calculated at $10.00 per rentable square foot for any portion of the
         Premises not included in Phase I. On the earlier of (i) December
         1, 2001, or (ii) the date Tenant's Work for Phase II is complete, the
         Rent for the balance of the Premises shall be adjusted to the amount
         set forth in Section 4(a) below on the basis of the actual TI Allowance
         provided by Landlord to Tenant for Phase II; provided, however that in
         no event shall such Rent be less than $13.00 per rentable square foot
         per annum. Upon request of Landlord, Tenant shall execute and deliver a
         written acknowledgment of the Rent Commencement Date and the expiration
         date of the Term when such are established and shall attach the
         acknowledgment to this Lease as part

                                       2

<PAGE>

         of Exhibit D; provided, however. Tenant's failure to execute and
         deliver such acknowledgment shall not affect Landlord's rights
         hereunder.

In addition, each reference in the Work Letter to the date "May 1, 2000" is
hereby changed to "June 1, 2000."

5.       LANDLORD'S WORK. Landlord and Tenant acknowledge and agree that:

                  (i)      All of Landlord's Work required for the commencement
                           and completion of Tenant's Work has been completed;

                  (ii)     Landlord has heretofore agreed to provide to Tenant
                           electric service of up to 2,000 amperes demand as
                           shown to be required by Tenant pursuant to a stamped,
                           sealed electrical load letter (or other document
                           reasonably satisfactory to Landlord) certified to
                           Landlord from Tenant's electrical engineer. Landlord
                           hereby agrees that such service shall be in existence
                           at the Project on or before May 1, 2000, subject to
                           Force Majeure Delay. For each day that such service
                           does not exist at the Project as required hereunder
                           for any reason other than Force Majeure Delay, the
                           Rent Commencement Date shall be delayed beyond June
                           1, 2000 the same number of days;

                  (iii)    Subject to receipt and approval of proposed plans and
                           specifications therefor, Landlord hereby grants
                           Tenant the right to erect, use and maintain, conduits
                           and wire from the Premises through the common areas
                           of the Project to the Project electrical room;

                  (iv)     In addition to the TI Allowance, Landlord shall
                           provide to Tenant an allowance of $10,000 for the
                           purpose solely of installing conduit and wire (and/or
                           reusing existing conduit and wire) from the Project
                           electrical room to the Premises central
                           mechanical/electrical room. Said allowance shall be
                           paid against invoices showing the completion of such
                           work;

                  (v)      Tenant's Work has not been delayed by reason of the
                           performance of Landlord's Work; and

                  (vi)     Tenant hereby accepts the Premises for the purpose of
                           construction of Tenant's Work.

Landlord and Tenant further agree that Landlord may delay certain exterior
improvements as described on Schedule A-1, attached hereto and incorporated
herein by this reference, until such work may be completed without undue
conflict with the work of completing Tenant's Work or with adverse winter
weather conditions; provided that such delayed exterior work shall be completed
no later than the later of June 1, 2000, or issuance of Tenant's occupancy
permit, subject in each case to Force Majeure Delays.

6.       EXHIBIT F. Attached hereto is Exhibit F to the Lease, which Exhibit F
may be amended in the future to include additional items agreed to by Landlord.

                                       3

<PAGE>

7.       MISCELLANEOUS.

         (a)      This Amendment is the entire agreement between the parties
with respect to the subject matter hereof and supersedes all prior and
contemporaneous oral and written agreements and discussions with respect to the
matters addressed herein. This Amendment may be amended only by an agreement in
writing, signed by the parties hereto.

         (b)      This Amendment is binding upon and shall inure to the benefit
of the parties hereto, their respective agents, employees, representatives,
officers, directors, divisions, subsidiaries, affiliates, assigns, heirs,
successors in interest and shareholders.

         (c)      This Amendment may be executed in any number of counterparts,
each of which shall be deemed an original, but all of which when taken together
shall constitute one and the same instrument. The signature page of any
counterpart may be detached therefrom without impairing the legal effect of the
signature(s) thereon provided such signature page is attached to any other
counterpart identical thereto except having additional signature pages executed
by other parties to this Amendment attached thereto.

         (d)      Except as amended and/or modified by this Amendment, the Lease
is hereby ratified and confirmed and all other terms of the Lease shall remain
in full force and effect, unaltered and unchanged by this Amendment. In the
event of any conflict between the provisions of this Amendment and the
provisions of the Lease, the provisions of this Amendment shall prevail. Whether
or not specifically amended by this Amendment, all of the terms and provisions
of the Lease are hereby amended to the extent necessary to give effect to the
purpose and intent of this Amendment.

         (e)      As a condition to the effectiveness of this Amendment, Tenant
shall issue to Landlord Warrants and other consideration pursuant to a separate
letter agreement.

         IN WITNESS WHEREOF, this First Amendment to Lease has been duly
executed and delivered by Landlord and Tenant as of the date first above
written.

                                   TENANT:

                                   MEMORY PHARMACEUTICALS CORP.,
                                   a Delaware corporation

                                   By:  /s/ Joanne Leonard
                                        --------------------------------
                                   Its: CFO

                                      4
<PAGE>

                                   LANDLORD:

                                   ARE - 100 PHILLIPS PARKWAY, LLC,
                                   a Delaware limited liability company

                                   By: ALEXANDRIA REAL ESTATE EQUITIES, L.P., a
                                       Delaware limited partnership, managing
                                       member

                                       By: ARE-QRS CORP., a Maryland
                                           corporation, general partner

                                           By:  /s/ Lynn Anne Shapiro
                                                --------------------------------
                                           Its: LYNN ANNE SHAPIRO
                                                GENERAL COUNSEL

                                       5

<PAGE>

                           SCHEDULE A-1 TO WORK LETTER

The following exterior improvements are required by the Borough of Montvale, New
Jersey pursuant to its adoption of the Resolution to Approve Landlord's Site
Plan Amendment Application on December 7, 1999, and may be delayed by Landlord,
in its sole discretion, until the later of June 1, 2000, or issuance of Tenant's
occupancy permit, subject in each case to Force Majeure Delays:

1.  Restripe and widen impervious coverage of parking and drive areas where
    required.

2.  Plant five (5) eight foot tall white pines, or equivalent species in
    required locations.

3.  Add railroad tie islands and plant materials at the median of the south
    parking area where required.

4.  Substitute wood guardrails in lieu of wood bollards at areas required.

5.  Add three (3) stop signs and one (1) do not enter sign where required.

6.  Demolish existing railroad tie planter in north parking lot. Reinstall new
    railroad ties and re-pave areas where needed.

7.  Construct dumpster enclosure with two (2) twelve foot (12') wide gates.

8.  Demolish existing concrete sidewalks and curbs and install two (2) dropped
    curbs at driveway main entrance and add concrete sidewalk where required.

9.  Electric work for six (6) site light bollards, six (6) glare shields for
    site lighting, and fire alarm light.

                                       1

<PAGE>

                                    EXHIBIT F

Rack Washer

Autoclaves

Glass Washer

Generator

Bottle Washer/Filler

Walk-in Refrigerator

                                       2

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