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                                                                   Exhibit 10.19

                             MASTER LEASE AGREEMENT
                                     (QUASI)
                   DATED AS OF NOVEMBER 10, 2004 ("AGREEMENT")

THIS AGREEMENT is between General Electric Capital Corporation (together with
its successors and assigns, if any, "Lessor") and Synta Pharmaceuticals Corp.
("Lessee"). Lessor has an office at 83 WOOSTER HEIGHTS ROAD, DANBURY, CT 06810.
Lessee is a corporation organized and existing under the laws of state of
Delaware. Lessee's mailing address and chief place of business is 45 HARTWELL
AVENUE, LEXINGTON, MA 02421. This Agreement contains the general terms that
apply to the leasing of Equipment from Lessor to Lessee. Additional terms that
apply the Equipment (term, rent, options, etc.) shall be contained on a schedule
("Schedule").

1.   LEASING:

(a)  Lessor agrees to lease to Lessee, and Lessee agrees to lease from Lessor,
the equipment and other property ("EQUIPMENT") described in any Schedule signed
by both parties.

(b)  Lessor shall purchase Equipment from the manufacturer or supplier
("SUPPLIER") and lease it to Lessee if on or before the Last Delivery Date
(specified in the Schedule) Lessor receives (i) a Schedule for the Equipment,
(ii) evidence of insurance which complies with the requirements of Section 8,
and (iii) such other documents as Lessor may reasonably request. Each of the
documents required above must be in form and substance satisfactory to Lessor.
Lessor hereby appoints Lessee its agent for inspection and acceptance of the
Equipment from the Supplier. Once the Schedule is signed, the Lessee may not
cancel the Schedule.

2.   TERM, RENT AND PAYMENT:

(a)  The rent payable for the Equipment and Lessee's right to use the Equipment
shall begin on the earlier of (i) the date when the Lessee signs the Schedule
and accepts the Equipment or (ii) when Lessee has accepted the Equipment under a
Certificate of Acceptance ("LEASE COMMENCEMENT DATE"). The term of this
Agreement shall be the period specified in the applicable Schedule. The word
"term" shall include all basic and any renewal terms.

(b)  Lessee shall pay rent to Lessor at its address stated above, except as
otherwise directed by Lessor. Rent payments shall be in the amount set forth in,
and due as stated in the applicable Schedule. If any Advance Rent (as stated in
the Schedule) is payable, it shall be due when the Lessee signs the Schedule.
Advance Rent shall be applied to the first rent payment. In no event shall any
Advance Rent or any other rent payments be refunded to Lessee. If rent is not
paid within ten (10) days of its due date, Lessee agrees to pay a late charge of
five cents ($.05) per dollar on, and in addition to, the amount of such rent but
not exceeding the lawful maximum, if any.

3.   TAXES:

(a)  If permitted by law, Lessee shall report and pay promptly all taxes, fees
and assessments due, imposed, assessed or levied against Lessor or Lessee on
account of any Equipment (or purchase, ownership, delivery, leasing, possession,
use or operation thereof) by any

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governmental entity or taxing authority during or related to the term of this
Agreement, including, without limitation, all license and registration fees, and
all sales, use, personal property, excise, franchise, stamp or other taxes,
imposts, duties and charges, together with any penalties, fines or interest
thereon(collectively "TAXES"). Lessee shall have no liability for Taxes imposed
by the United States of America or any State or political subdivision thereof or
any foreign jurisdiction which are on or measured by the net income of Lessor,
and any such Taxes are excluded from "Taxes" as such term is used throughout
this Agreement. Lessee shall promptly reimburse Lessor (on an after tax basis)
for any Taxes charged to or assessed against Lessor. Lessee shall send Lessor a
copy of each report or return and evidence of Lessees payment of Taxes upon
request.

(b)  Lessee's obligations, and Lessor's rights and privileges, contained in this
Section 3 shall survive the expiration or other termination of this Agreement.

4.   REPORTS:

(a)  If any tax or other lien shall attach to any Equipment, Lessee will notify
Lessor in writing, within ten (10) days after Lessee becomes aware of the tax or
lien. The notice shall include the full particulars of the tax or lien and the
location of such Equipment on the date of the notice.

(b)  Lessee will deliver to Lessor financial statements as follows: If Lessee is
a privately held company, then Lessee agrees to provide quarterly financial
statements, certified by Lessee's president or chief financial officer including
a balance sheet, statement of operations and cash flow statement within 30 days
of each quarter end and its complete audited annual financial statements,
certified by a reorganized firm of certified public accountants, within 120 days
of fiscal year end or at such time as Lessee's Board of Directors receives the
audit. If Lessee is a publicly held company, then Lessee agrees to provide
quarterly unaudited statements and annual audited statements, certified by a
recognized firm of certified public accountants, within 10 days after the
statements are provided to the Securities and Exchange Commission ("SEC") or
make such statements available on its website. All such statements are to be
prepared using generally accepted accounting principles ("GAAP") and, if Lessee
is a publicly held company, are to be in compliance with SEC requirements.

(c)  Lessor may inspect any Equipment during normal business hours after giving
Lessee reasonable prior notice.

(d)  Lessee will keep the Equipment at the Equipment Location (specified in the
applicable Schedule) and will give Lessor prior written notice of any relocation
of Equipment. If Lessor requests, Lessee will promptly notify Lessor in writing
of the location of any Equipment.

(e)  If any Equipment is lost or damaged (where the estimated repair costs would
exceed the greater of ten percent (10%) of the original Equipment cost or ten
thousand and 00/100 dollars ($10,000), or is otherwise involved in an accident
causing personal injury or property damage, Lessee will promptly and fully
report the event to Lessor in writing.

(f)  If Lessor requests, Lessee will furnish a certificate of an authorized
officer of Lessee stating that he has reviewed the activities of Lessees and
that, to the best of his knowledge, there

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exists no default or event which with notice or lapse of time (or both) would
become such a default within thirty (30) days after any request by Lessor.

(g)  Lessee will promptly notify Lessor of any change in Lessee's state of
incorporation or organization.

5.   DELIVERY, USE AND OPERATION:

(a)  All Equipment shall be shipped directly from the Supplier to Lessee.

(b)  Lessee agrees that the Equipment will be used by Lessee solely in the
conduct of its business and in a manner complying with all applicable laws,
regulations and insurance policies.

(c)  Lessee will not move any equipment from its leased or owned locations
("LOCATION"), except for purposes of repair, refurbishment or maintenance, and
Lessee will not move any piece of Equipment with an original equipment value of
$25,000 or more from one Location to another Location without written
notification to Lessor.

(d)  Lessee will keep the Equipment free and clear of all liens and encumbrances
other than those which result from acts of Lessor.

(e)  Lessor shall not disturb Lessees quiet enjoyment of the Equipment during
the term of the Agreement unless a default has occurred and is continuing under
this Agreement.

6.   MAINTENANCE:

(a)  Lessee will, at its sole expense, maintain each unit of Equipment in good
operating order and repair, normal wear and tear excepted. The Lessee shall also
maintain the Equipment in accordance with manufacturers recommendations. Lessee
shall make all alterations or modifications required to comply with any
applicable law, rule or regulation during the term of this Agreement. If Lessor
requests, Lessee shall affix plates, tags or other identifying labels showing
ownership thereof by Lessee and Lessor's security interest therein. The tags or
labels shall be placed in a prominent position on each unit of Equipment.

(b)  Lessee will not attach or install anything on the Equipment that will
impair the originally intended function or use of such Equipment without the
prior written consent of Lessor, which consent may not be withheld, conditioned
or delayed unreasonably. All additions, parts, supplies, accessories, and
equipment ("ADDITIONS") furnished or attached to any Equipment that are not
readily removable shall become subject to the lien or Lessor. All Additions
shall be made only in compliance with applicable law. Lessee will not attach or
install any Equipment to or in any other personal or real property without the
prior written consent of Lessor, which consent may not be withheld, conditioned
or delayed unreasonably.

7.   STIPULATED LOSS VALUE: If for any reason any unit of Equipment becomes
lost, stolen, destroyed, irreparably damages or unusable ("CASUALTY
OCCURRENCES") Lessee shall promptly and fully notify Lessor in writing. Lessee
shall pay Lessor the sum of (i) the Stipulated Loss Value (see Schedule) of the
affected unit determined as of the rent payment date prior to the casualty
Occurrence; and (ii) all rent and other amounts which are then due under this

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Agreement on the Payment Date (defined below) for the affected unit. The Payment
Date shall be the next rent payment after the Casualty Occurrence. Upon payment
of all sums due hereunder, the term of this lease as to such unit shall
terminate.

8.   INSURANCE:

(a)  Lessee shall bear the entire risk of any loss, theft, damage to, or
destruction of, any unit of Equipment from any cause whatsoever from the time
the Equipment is delivered to Lessee and installed (if applicable).

(b)  Lessee agrees, at its own expense, to keep all Equipment insured for such
amounts and against such hazards as Lessor may reasonably require. All such
policies shall be with companies, and on terms, reasonably satisfactory to
Lessor. The insurance shall include coverage for damage to or loss of Equipment,
liability for personal injuries, death or property damage. Lessor shall be named
as additional insured with a loss payable clause in favor of Lessor, as its
interest may appear, irrespective of any breach of warranty or other act or
omission of Lessee. The insurance shall provide for liability coverage in any
amount equal to at least ONE MILLION U.S. DOLLARS ($1,000,000.00) total
liability per occurrence, unless otherwise stated in any Schedule. The
casualty/property damage coverage shall be in an amount equal to the higher of
the Stipulated Loss Value or the full replacement cost of the Equipment. No
insurance shall be subject to any co-insurance clause. The insurance policies
shall provide that the insurance may not be altered or canceled by the insurer
until after thirty (30) days written notice to Lessor. Lessee agrees to deliver
to Lessor evidence of insurance reasonable satisfactory to Lessor.

(c)  Lessee hereby appoints to Lessor as Lessee's attorney-in-fact to make proof
of loss and claim for insurance, and to make adjustments with insurers and to
receive payment of an execute or endorse all documents, checks or drafts in
connection with insurance payments. Lessor shall not act a Lessees
attorney-in-fact unless Lessee is in default. Lessee shall pay any reasonable
expenses if Lessor in adjusting or collecting insurance. Lessee will not make
adjustments with insurers except with respect to claims for damage to any unit
of Equipment where the repair costs are less than the lesser of ten percent
(10%) of the original Equipment cost or ten thousand and 00/100 dollars
($10,000). Lessor may, at its option, apply proceeds of insurance, in whole or
in part, to (i) repair or replace Equipment or any portion thereof, or (ii)
satisfy any obligation of Lessee to Lessor under this Agreement.

9.   RETURN OF EQUIPMENT:

(a)  At the expiration or termination of this Agreement or any Schedule, Lessee
shall perform any testing and repairs required to place the units of Equipment
in the same condition and appearance as when received by Lessee (reasonable wear
and tear excepted) and in good working order for the original intended purpose
of the Equipment. If required the units of Equipment shall be deinstalled,
disassembled and crated by an authorized manufacturer's representative or such
other service person as is reasonably satisfactory to Lessor. Lessee shall
remove installed markings that are not necessary for the operation, maintenance
or repair of the Equipment. All Equipment will be cleaned, cosmetically
acceptable, and in such condition as to be immediately installed into use in a
similar environment for which the Equipment was

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originally intended to be used. All waste material and fluid must be removed
from the Equipment and disposed of in accordance with then current waste
disposal laws. Lessee shall return the units of Equipment to a location within
the continental United States as Lessor shall direct. Lessee shall obtain and
pay for a policy of transit insurance for the redelivery period in an amount
equal to the replacement value of the Equipment. The transit insurance must name
Lessor as the loss payee. The Lessee shall pay for all costs to comply with this
section (a).

(b)  Until Lessee has fully complied with the requirements of Section 9(a)
above, Lessee's rent payment obligation and all other obligations under this
Agreement shall continue from month to month notwithstanding any expiration or
termination of the lease term. Lessor may not terminate the Lessee's right to
use Equipment, unless Lessee is in default.

(c)  Lessee shall provide to Lessor a detailed inventory of all components of
the Equipment including model and serial numbers. Lessee shall also provide an
up-to-date copy of all other documentation pertaining to the Equipment. All
service manuals, blueprints, process flow diagrams, operating manuals, inventory
and maintenance records shall be given to Lessor at least ninety (90) days and
not more than one hundred twenty (120) days prior to lease termination.

(d)  Lessee shall make the Equipment available for on-site operational
inspections by potential purchasers at least one hundred twenty (120) days prior
to and continuing up to lease termination. Lessor shall provide Lessee with
reasonable notice prior to any inspection. Lessee shall provide personnel, power
and other requirements necessary to demonstrate electrical, hydraulic and
mechanical systems for each item of Equipment.

10.  DEFAULT AND REMEDIES:

(a)  Lessor may in writing declare this Agreement in default if: (i) Lessee
breaches its obligation to pay rent or any other sum when due and fails to cure
the breach within ten (10) days; (ii) Lessee breaches any of its insurance
obligations under Section 9; (iii) Lessee breaches any of its other obligations
and fails to cure that breach within thirty (30) days after written notice from
Lessor; (iv) any representation or warranty made by Lessee in connection with
this Agreement shall be false or misleading in any material respect; (v) Lessee
or any guarantor or other obligor for the Lessee's obligations hereunder
("GUARANTOR") becomes insolvent or ceases to do business as a going concern;
(vi) any Equipment is illegally used; (vii) if Lessee or any Guarantor is a
natural person, any death or incompetency of Lessee or such Guarantor; (viii) a
petition is filed by or against Lessee or any Guarantor under any bankruptcy or
insolvency laws and in the event of an involuntary petition, the petition is not
dismissed, within forty-five (45) days of the filing date; (ix) Lessee default
under any other material obligation for (A) borrowed money, (B) the deferred
purchase price of property, or (C) payments due under the lease agreement; (x)
there is any dissolution, termination or existence, merger, consolidation or
change in controlling ownership or Lessee or any Guarantor, but not to include
an initial public offering, or any other stock offering, preferred to common, in
which the primary purpose is to raise cash equity; or (xi) there is a material
adverse change in the Lessee's financial condition. The default declaration
shall apply to all Schedules unless specifically excepted by Lessor.

(b)  After a default, at the request of Lessor, Lessee shall comply with the
provisions of Section 9(a) and the following provisions shall apply also. Lessee
hereby authorizes Lessor to

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peacefully enter any premises where any Equipment may be and take possession of
the Equipment. Lessee shall immediately pay to Lessor without further demand as
liquidated damages for loss of a bargain and not as a penalty, the Stipulated
Loss Value of the Equipment (calculated as of the rent payment date prior to the
declaration of default), and all rents and other sums then due under this
Agreement and all Schedules. Lessor may terminate this Agreement as to any or
all of the Equipment. A termination shall occur only upon written notice by
Lessor to Lessee and only as to the units of Equipment specified in any such
notice. Lessor may, but shall not be required to, sell Equipment at private or
public sale, in bulk or in parcels, with or without notice, and without having
the Equipment present at the place of sale. Lessor may also, but shall not be
required to, lease, otherwise dispose of or keep idle all or part of the
Equipment. Lessor may use Lessee's premises for a reasonable period of time for
any or all of the purposes stated above without liability for rent, costs,
damages or otherwise. The proceeds of sale, lease or other disposition, if any,
shall be applied in the following order of priorities: (i) to pay all of
Lessor's costs, charges and expenses incurred in taking, removing, holding,
repairing and selling, leasing or otherwise disposing of Equipment; then (ii) to
the extent not previously paid by Lessee, to pay Lessor all sums due from Lessee
under this Agreement; then (iii) to reimburse to Lessee any sums previously paid
by Lessee as liquidated damages; and then (iv) to Lessee, if there exists any
surplus. Lessee shall immediately pay any deficiency in (i) and (ii) above.

(c)  The foregoing remedies are cumulative, and any or all thereof may be
exercised instead of or in addition to each other or any remedies at law, in
equity, or under statute. Lessee waives notice of sale or other disposition (and
the time and place thereof), and the manner and place of any advertising. Lessee
shall pay Lessor's actual attorney's fees incurred in connection with the
enforcement, assertion, defense or preservation of Lessor's rights and remedies
under this Agreement, or if prohibited by law, such lesser sum as may be
permitted. Waiver of any default shall not be a waiver of any other or
subsequent default.

(d)  Any default under the terms of this or any other agreement between Lessor
and Lessee may be declared by Lessor a default under this and any such other
agreement.

11.  ASSIGNMENT: LESSEE SHALL NOT SELL, TRANSFER, ASSIGN, ENCUMBER OR SUBLET ANY
EQUIPMENT OR THE INTEREST OF LESSEE IN THE EQUIPMENT WITHOUT THE PRIOR WRITTEN
CONSENT OF LESSOR. Lessor may, without the consent of Lessee, assign this
Agreement, any Schedule or the right to enter into a Schedule. Lessee agrees
that is Lessee receives written notice of an assignment from Lessor, Lessee will
pay all rent and all other amounts payable under any assigned Schedule to such
assignee or as instructed by Lessor. Lessee also agrees to confirm in writing
receipt of the notice of assignment as may be reasonably requested by assignee.
Lessee hereby waives and agrees not to assert against any such assignee any
defense, set-off, recoupment claim or counterclaim which Lessee has or may at
any time have against Lessor for any reason whatsoever.

12.  NET LEASE: Lessee is unconditionally obligated to pay all rent and other
amounts due for the entire lease term no matter what happens, even if the
Equipment is damaged or destroyed, if it is defective or if Lessee no longer can
use it. Lessee is not entitled to reduce or set-off against rent or other
amounts due to Lessor or to anyone to whom Lessor assigns this Agreement or any
Schedule whether Lessees claim arises out of this Agreement, any Schedule, any

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statement by Lessor, Lessor's liability of any manufacturers liability, strict
liability, negligence or otherwise.

13.  INDEMNIFICATION:

(a)  Lessee hereby agrees to indemnify Lessor, its agents, employees, successors
and assigns (on an after tax basis) from and against any and all losses,
damages, penalties, injuries, claims, actions and suits, including legal
expenses, of whatsoever kind and nature arising out of or relating to the
Equipment or this Agreement, except to the extent the losses, damages,
penalties, injuries, claims, actions, suits or expenses result from Lessor's
gross negligence or willful misconduct ("CLAIMS"). This indemnity shall include,
but is not limited to, Lessor's strict liability in tort and Claims, arising out
of (i) the selection, manufacture, purchase, acceptance or rejection of
Equipment, the ownership of Equipment during the term of this Agreement, and the
delivery, lease, possession, maintenance, uses, condition, return or operation
of Equipment (including, without limitation, latent and other defects, whether
or not discoverable by Lessor or Lessee and any claim for patent, trademark or
copyright infringement or environmental damage) or (ii) the condition of
Equipment sold or disposed of after use by Lessee, any sublessee or employees of
Lessee. Lessee shall, upon request, defend any actions based on, or arising out
of, any of the foregoing.

(b)  All of Lessor's rights, privileges and indemnities contained in this
Section 13 shall survive the expiration or other termination of this Agreement.
The rights, privileges and indemnities contained herein are expressly made for
the benefit of, and shall be enforceable by Lessor, its successors and assigns.

14.  DISCLAIMER: LESSEE ACKNOWLEDGES THAT IT HAS SELECTED THE EQUIPMENT WITHOUT
ANY ASSISTANCE FROM LESSOR, ITS AGENTS OR EMPLOYEES. LESSOR DOES NOT MAKE, HAS
NOT MADE, NOR SHALL BE DEEMED TO MAKE OR HAVE MADE, ANY WARRANTY OR
REPRESENTATION, EITHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, WITH RESPECT TO THE
EQUIPMENT LEASED UNDER THIS AGREEMENT OR ANY COMPONENT THEREOF, INCLUDING,
WITHOUT LIMITATION, ANY WARRANTY AS TO DESIGN, COMPLIANCE WITH SPECIFICATIONS,
QUALITY OF MATERIALS OR WORKMANSHIP, MERCHANTABILITY, FITNESS FOR ANY PURPOSE,
USE OR OPERATION, SAFETY, PATENT, TRADEMARK OR COPYRIGHT INFRINGEMENT, OR TITLE.
All such risks, as between Lessor and Lessee, are to be borne by Lessee. Without
limiting the foregoing, Lessor shall have no responsibility or liability to
Lessee or any other person with respect to any of the following: (i) any
liability, loss or damage caused or alleged to be caused directly or indirectly
by any Equipment, any inadequacy thereof, any deficiency or defect (latent or
otherwise) of the Equipment, or any other circumstance in connection with the
Equipment; (ii) the use, operation or performance of any Equipment or any risks
relating to it, (iii) any interruption of service, loss of business or
anticipated profits or consequential damages; or (iv) the delivery, operation,
servicing, maintenance, repair, improvement or replacement of any Equipment. If,
and so long as, no default exists under this Agreement, Lessee shall be, and
hereby is, authorized during the term of this Agreement to assert and enforce,
whatever claims and rights Lessor may have against any Supplier of the Equipment
at Lessee's sole cost and

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expense, in the name of and for the account of Lessor and/or Lessee, as their
interests may appear.

15.  REPRESENTATIONS AND WARRANTIES OF LESSEE: Lessee makes each of the
following representations and warranties to Lessor on the date hereof and on the
date of execution of each Schedule:

(a)  Lessee has adequate power and capacity to enter into, and perform under,
this Agreement and all related documents (together, the "DOCUMENTS"). Lessee is
duly qualified to do business wherever necessary to carry on its present
business and operations, including the jurisdiction(s) where the Equipment is or
is to be located.

(b)  The Documents have been duly authorized, executed and delivered by Lessee
and constitute valid, legal and binding agreements, enforceable in accordance
with their terms, except to the extent that the enforcement of remedies may be
limited under applicable bankruptcy and insolvency laws.

(c)  No approval, consent or withholding of objections is required from any
governmental authority or entity with respect to the entry into or performance
by Lessee of the Documents except such as have already been obtained.

(d)  The entry into and performance by Lessee of the Documents will not: (i)
violate any judgment, order, law or regulation applicable to Lessee or any
provision of Lessee's Certificate of Incorporation or bylaws; or (ii) result in
any breach of, constitute a default under or result in the creation of any lien,
charge, security interest or other encumbrance upon any Equipment pursuant to
any indenture, mortgage, deed of trust, bank loan or credit agreement or other
instrument (other than this Agreement) to which Lessee is a party,

(e)  There are no suits or proceedings pending or threatened in court or before
any commission, board or other administrative agency against or affecting
Lessee, which if decided against Lessee will have a material adverse effect on
the ability of Lessee to fulfill its obligations under this Agreement.

(f)  The Equipment accepted under any Certificate of Acceptance is and will
remain tangible personal property.


(g)  Each financial statement delivered to Lessor has been prepared in
accordance with generally accepted accounting principles consistently applied.
Since the date of the most recent financial statement, there has been no
material adverse change.

(h)  Lessee's exact legal name is as set forth in the first sentence of this
Agreement and Lessee is and will be at all times validly existing and in good
standing under the laws of the State of its incorporation (specified in the
first sentence of this Agreement).

(i)  The Equipment will at all times be used for commercial or business
purposes.

(j)  Lessee is and will remain in full compliance with all laws and regulations
applicable to it including, without limitation,' (i) ensuring that no person who
owns a controlling interest in or

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otherwise controls Lessee is or shall be (Y) listed on the Specially Designated
Nationals and Blocked Person List maintained by the Office of Foreign Assets
Control ("OFAC"), Department of the Treasury, and/or any other similar lists
maintained by OFAC pursuant to any authorizing statute, Executive Order or
regulation or (Z) a person designated under Section 1(b), (c) or (d) of
Executive Order No. 13224 (September 23, 2001), any related enabling legislation
or any other similar Executive Orders, and (ii) compliance with all applicable
Bank Secrecy Act ("BSA") laws, regulations and government guidance on BSA
compliance and on the prevention and detection of money laundering violations.

16.  OWNERSHIP FOR TAX PURPOSES, GRANT OF SECURITY INTEREST; USURY SAVINGS:

(a)  For income tax purposes, the parties hereto agree that it is their mutual
intention that Lessee shall be considered the owner of the Equipment.
Accordingly, Lessor agrees (i) to treat Lessee as the owner of the Equipment on
Its federal income tax return, (ii) not to take actions or positions
inconsistent with such treatment on or with respect to its federal income tax
return, and (iii) not to claim any tax benefits available to an owner of the
Equipment on or with respect to its federal income tax return. The foregoing
undertakings by Lessor shall not be violated by Lessor's taking a tax position
inconsistent with the foregoing sentence to the extent such a position is
required by law or is taken through inadvertence so long as such inadvertent tax
position is reversed by Lessor promptly upon its discovery, Lessor shall in no
event be liable to Lessee if Lessee fails to secure any of the tax benefits
available to the owner of the Equipment.

(b)  Lessee hereby grants to Lessor a first security interest in the Equipment,
together with all additions, attachments, accessions, accessories and accessions
thereto whether or not furnished by the Supplier of the Equipment and any and
all substitutions, replacements or exchanges therefor, and any and all insurance
and/or other proceeds of the property in and against which a security interest
is granted hereunder. This security interest is given to secure the payment and
performance of all debts, obligations and liabilities of any kind whatsoever of
Lessee to Lessor, now existing or arising in the future under this Agreement or
any Schedules attached hereto, and any renewals, extensions and modifications of
such debts, obligations and liabilities.

(c)  It is the intention of the parties hereto to comply with any applicable
usury laws to the extent that any Schedule is determined to be subject to such
laws; accordingly, it is agreed that, notwithstanding any provision to the
contrary in any Schedule or this Agreement, in no event shall any Schedule
require the payment or permit the collection of interest in excess of the
maximum amount permitted by applicable law. If any such excess interest is
contracted for, charged or received under any Schedule or this Agreement, or in
the event that all of the principal balance shall be prepaid, so that under any
of such circumstances the amount of interest contracted for, charged or received
under any Schedule or this Agreement shall exceed the maximum amount of interest
permitted by applicable law, then in such event (i) the provisions of this
paragraph shall govern and control, (ii) neither Lessee nor any other person or
entity now or hereafter liable for the payment hereof shall be obligated to pay
the amount of such interest to the extent that it is in excess of the maximum
amount of interest permitted by applicable law, (iii) any such excess which may
have been collected shall be either applied as a credit against the then unpaid
principal balance or refunded to Lessee, at the option of' the Lessor, and (iv)
the effective rate of interest shall be automatically reduced to the maximum
lawful contract rate

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allowed under applicable law as now or hereafter construed by the courts having
jurisdiction thereof. It is further agreed that without limitation of the
foregoing, all calculations of the rate of interest contracted for, charged or
received under any Schedule or this Agreement which are made for the purpose of
determining whether such rate exceeds the maximum lawful contract rate, shall be
made, to the extent permitted by applicable law, by amortizing, prorating,
allocating and spreading in equal parts during the period of the full stated
term of the indebtedness evidenced hereby, all interest at any time contracted
for, charged or received from Lessee or otherwise by Lessor in connection with
such indebtedness; provided, however, that if any applicable state law is
amended or the law of the United States of America preempts any applicable state
law, so that it becomes lawful for Lessor to receive a greater interest per
annum rate than is presently allowed, the Lessee agrees that, on the effective
date of such amendment or preemption, as the case may be, the lawful maximum
hereunder shall be increased to the maximum interest per annum rate allowed by
the amended state law or the law of the United States of America.

17.  EARLY TERMINATION:

(a)  On or after the First Termination Date (specified in the applicable
Schedule), Lessee may, so long as no default exists hereunder, terminate this
Agreement as to all (but not less than alt) of the Equipment on such Schedule as
of a rent payment date ("TERMINATION DATE"). Lessee must give Lessor at least
ninety (90) days prior written notice of the termination.

(b)  Lessee shall, and Lessor may, solicit cash bids for the Equipment on an AS
IS, WHERE IS BASIS without recourse to or warranty from Lessor, express or
implied ("AS IS BASIS"). Prior to the Termination Date, Lessee shall (i) certify
to Lessor any bids received by Lessee and (ii) pay to Lessor (A) the Termination
Value (calculated as of the rent due on the Termination Date) for the Equipment,
and (8) all rent and other sums due and unpaid as of the Termination Date.

(c)  If all amounts due hereunder have been paid on the Termination Date, Lessor
shall (i) sell the Equipment on an AS IS BASIS for cash to the highest bidder
and (ii) refund the proceeds of such sale (net of any related expenses) to
Lessee up to the amount of the Termination Value. If such sale is not
consummated, no termination shall occur and Lessor shall refund the Termination
Value (less any expenses incurred by Lessor) to Lessee.

(d)  Notwithstanding the foregoing, Lessor may elect by written notice, at any
time prior to the Termination Date, not to sell the Equipment. In that event, on
the Termination Date Lessee shall (i) return the Equipment (in accordance with
Section 9) and (ii) pay to Lessor all amounts required under Section 17(b) less
the amount of the highest bid certified by Lessee to Lessor.

18.  EARLY PURCHASE OPTION:

(a)  Lessee may purchase on an AS IS BASIS all (but not less than all) of the
Equipment on any Schedule on any Rent Payment Date after the First Termination
Date specified in the applicable Schedule but prior to the last Rent Payment
Date of such Schedule (the "EARLY PURCHASE DATE"), for a price equal to (i) the
Termination Value (calculated as of the Early Purchase Date) for the Equipment,
and (ii) all rent and other sums due and unpaid as of the Early

                                       10
<Page>

Purchase Date (the "EARLY OPTION PRICE"), plus all applicable sales taxes.
Lessee must notify Lessor of its intent to purchase the Equipment in writing at
least thirty (30) days, but not more than two hundred seventy (270) days, prior
to the Early Purchase Date. If Lessee is in default or if the Schedule or this
Agreement has already been terminated, Lessee may not purchase the Equipment.
(The purchase option granted by this subsection shall be referred to herein as
the "EARLY PURCHASE OPTION").

(b)  If Lessee exercises its Early Purchase Option, then on the Early Purchase
Date, Lessee shall pay to Lessor any rent and other sums due and unpaid on the
Early Purchase Date and Lessee shall pay the Early Option Price, plus all
applicable sales taxes, to Lessor in cash.

19.  END OF LEASE PURCHASE OPTION: Lessee may, at lease expiration, purchase all
(but not less than all) of the Equipment on any Schedule on an AS IS BASIS for
cash equal to the amount indicated on such Schedule (the "OPTION PAYMENT"), plus
all applicable sales taxes. The Option Payment, plus all applicable sales taxes,
shall be due and payable in immediately available funds on the expiration date
of such Schedule. Lessee must notify Lessor of its intent to purchase the
Equipment in writing at least one hundred eighty (180) days prior to the
expiration date of the Schedule. If Lessee is in default, or if the Schedule or
this Agreement has already been terminated, Lessee may not purchase the
Equipment.

20.  MISCELLANEOUS:

(a)  LESSEE AND LESSOR UNCONDITIONALLY WAIVE THEIR RIGHTS TO A JURY TRIAL OF ANY
CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT, ANY OF THE
RELATED DOCUMENTS, ANY DEALINGS BETWEEN LESSEE AND LESSOR RELATING TO THE
SUBJECT MATTER OF THIS TRANSACTION OR ANY RELATED TRANSACTIONS, AND/OR THE
RELATIONSHIP THAT IS BEING ESTABLISHED BETWEEN LESSEE AND LESSOR. THE SCOPE OF
THIS WAIVER IS INTENDED TO BE ALL ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY
BE FILED IN ANY COURT. THIS WAIVER IS IRREVOCABLE. THIS WAIVER MAY NOT BE
MODIFIED EITHER ORALLY OR IN WRITING. THE WAIVER ALSO SHALL APPLY TO ANY
SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT,
ANY RELATED DOCUMENTS, OR TO ANY OTHER DOCUMENTS OR AGREEMENTS RELATING TO THIS
TRANSACTION OR ANY RELATED TRANSACTION. THIS AGREEMENT MAY BE FILED AS A WRITTEN
CONSENT TO A TRIAL BY THE COURT.

(b)  Any cancellation or termination by Lessor of this Agreement, any Schedule,
supplement or amendment hereto, or the lease of any Equipment hereunder shall
not release Lessee from any then outstanding obligations to Lessor hereunder.
All Equipment shall at all times remain personal property even though it may be
attached to real property. The Equipment shall not become part of any other
property by reason of any installation in, or attachment to, other real or
personal property.

(c)  Time is of the essence of this Agreement. Lessor's failure at any time to
require strict performance by Lessee of any of the provisions hereof shall not
waive or diminish Lessor's right at any other time to demand strict compliance
with this Agreement Lessee agrees, upon Lessor's

                                       11
<Page>

request, to execute, or otherwise authenticate, any document, record or
instrument necessary or expedient for filing, recording or perfecting the
interest of Lessor or to carry out the intent of this Agreement. In addition,
Lessee hereby authorizes Lessor to file a financing statement and amendments
thereto describing the Equipment described in any and all Schedules now and
hereafter executed pursuant hereto and adding any other collateral described
therein and containing any other information required by the applicable Uniform
Commercial Code. Lessee irrevocably grants to Lessor the power to sign Lessee's
name and generally to act on behalf of Lessee to execute and file financing
statements and other documents pertaining to any or all of the Equipment. Lessee
hereby ratifies its prior authorization for Lessor to file financing statements
and amendments thereto describing the Equipment and containing any other
information required by any applicable law (including without limitation the
Uniform Commercial Code) if filed prior to the date hereof. All notices required
to be given hereunder shall be deemed adequately given if sent by registered or
certified mail to the addressee at its address stated herein, or at such other
place as such addressee may have specified in writing. This Agreement and any
Schedule and Annexes thereto constitute the entire agreement of the parties with
respect to the subject matter hereof. NO VARIATION OR MODIFICATION OF THIS
AGREEMENT OR ANY WAIVER OF ANY OF ITS PROVISIONS OR CONDITIONS, SHALL BE VALID
UNLESS IN WRITING AND SIGNED BY AN AUTHORIZED REPRESENTATIVE OF THE PARTIES
HERETO.

(d)  If Lessee does not comply with any provision of this Agreement, Lessor
shall have the right, but shall not be obligated, to effect such compliance, in
whole or in part. All reasonable amounts spent and obligations incurred or
assumed by Lessor in effecting such compliance shall constitute additional rent
due to Lessor. Lessee shall pay the additional rent within ten (10) days after
the date Lessor sends notice to Lessee requesting payment Lessor's effecting
such compliance shall not be a waiver of Lessee's default.

(e)  Any rent or other amount not paid to Lessor when due shall bear interest,
from the due date until paid, at the lesser of eighteen percent (18%) per annum
or the maximum rate allowed by law. Any provisions in this Agreement and any
Schedule that are in conflict with any statute, law or applicable rule shall be
deemed omitted, modified or altered to conform thereto. Notwithstanding anything
to the contrary contained in this Agreement or any Schedule, in no event shall
this Agreement or any Schedule require the payment or permit the collection of
amounts in excess of the maximum permitted by applicable law.

(f)  Lessee hereby irrevocably authorizes Lessor to adjust the Capitalized
Lessor's Cost up or down by no more than ten percent [10%] within each Schedule
to account for equipment change orders, equipment returns, invoicing errors, and
similar matters. Lessee acknowledges and agrees that the rent shall be adjusted
as a result of the change in the Capitalized Lessor's Cost. Lessor shall send
Lessee a written notice stating the final Capitalized Lessor's Cost, if it has
changed.

(g)  THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER
SHALL IN ALL RESPECTS BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH, THE
INTERNAL LAWS OF THE STATE OF CONNECTICUT (WITHOUT REGARD TO THE CONFLICT OF
LAWS PRINCIPLES OF SUCH STATE), INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY
AND PERFORMANCE, REGARDLESS OF THE LOCATION OF THE EQUIPMENT.

                                       12
<Page>

(h)  Any cancellation or termination by Lessor, pursuant to the provisions of
this Agreement, any Schedule, supplement or amendment hereto, of the lease of
any Equipment hereunder, shall not release Lessee from any then outstanding
obligations to Lessor hereunder.

(i)  To the extent that any Schedule would constitute chattel paper, as such
term is defined in the Uniform Commercial Code as in effect in any applicable
jurisdiction, no security interest therein may be created through the transfer
or possession of this Agreement in and of itself without the transfer or
possession of the original of a Schedule executed pursuant to this Agreement and
incorporating this Agreement by reference; and no security interest in this
Agreement and a Schedule may be created by the transfer or possession of any
counterpart of the Schedule other than the original thereof, which shall be
identified as the document marked Original and all other counterparts shall be
marked Duplicate.

(j)  Each party hereto agrees to keep confidential, the terms and provisions of
the Documents and the transactions contemplated hereby and thereby
(collectively, the "TRANSACTIONS"), except that each party may make disclosure
to the extent required by law and Lessee may make confidential disclosure to its
significant investors, potential business partners and/or potential investors.
Notwithstanding the foregoing, the obligations of confidentiality contained
herein, as they relate to the Transactions, shall not apply to the federal tax
structure or federal tax treatment of the Transactions, and each party hereto
(and any employee, representative, or agent of any party hereto) may disclose to
any and all persons, without limitation of any kind, the federal tax structure
and federal tax treatment of the Transactions. The preceding sentence is
intended to cause each Transaction to be treated as not having been offered
under conditions of confidentiality for purposes of Section I.6011-4(b)(3) (or
any successor provision) of the Treasury Regulations promulgated under Section
6011 of the Internal Revenue Code of 1986, as amended, and shall be construed in
a manner consistent with such purpose. In addition, each party hereto
acknowledges that it has no proprietary or exclusive rights to the federal tax
structure of the Transactions or any federal tax matter or federal tax idea
related to the Transactions.

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


LESSOR:                                  LESSEE:

GENERAL ELECTRIC CAPITAL CORPORATION     SYNTA PHARMACEUTICALS CORP.

By:    /s/ JOHN EDEL                     By:    /s/ KEITH EHRLICH
       -------------------------------          --------------------------------

Name:  John Edel                         Name:  Keith Ehrlich
       -------------------------------          --------------------------------

Title: SVP                               Title: VP of Finance and Administration
       -------------------------------          --------------------------------

                                       13
<Page>

                          EQUIPMENT CONCENTRATION RIDER

SYNTA PHARMACEUTICALS CORP. ("Customer"), on or before October 19, 2005, shall
cause the composition and mix of Equipment financed after November 10, 2004
under the Master Lease Agreement dated as of November 10, 2004 between Customer
and General Electric Capital Corporation to conform to and meet the following
concentration requirements (hereinafter "Concentration Requirements") for each
class of Equipment (hereinafter "Equipment Class") as identified and set forth
below. Customer herein represents and warrants that it shall maintain each such
Equipment Class and its respective Concentration Requirement from and after such
above referenced date and continuing thereafter to the end of the term:

<Table>
<Caption>
     EQUIPMENT CLASS                          CONCENTRATION REQUIREMENT
     ---------------                          -------------------------
     <S>                                      <C>
     Laboratory & scientific equipment:       Minimum of 60%

     General Office equipment, Computers      Maximum of 15%
     & similar:

     Soft costs (leaseholds, software,        Maximum of 25%
     & similar):
</Table>

Accepted and Agreed:

SYNTA PHARMACEUTICALS CORP.

By:    /s/ KEITH EHRLICH
       -----------------------------------

Title: VP of Finance and Administration
       -----------------------------------

Date:  11/11/04
       -----------------------------------

<Page>

                               EQUIPMENT SCHEDULE
                           (QUASI LEASE - FIXED RATE)
                                SCHEDULE NO. 001
                               DATED THIS 11/23/04
                            TO MASTER LEASE AGREEMENT
                          DATED AS OF NOVEMBER 10, 2004

LESSOR & MAILING ADDRESS:                        LESSEE & MAILING ADDRESS:
GENERAL ELECTRIC CAPITAL CORPORATION             SYNTA PHARMACEUTICALS CORP.
83 WOOSTER HEIGHTS RD. 5TH FLOOR                 45 HARTWELL AVENUE
DANBURY, CT 06810                                LEXINGTON, MA 02421

This Schedule is executed pursuant to, and incorporates by reference the terms
and conditions of, and capitalized terms not defined herein shall have the
meanings assigned to them in, the Master Lease Agreement identified above
("Agreement", said Agreement and this Schedule being collectively referred to as
"Lease"). This Schedule, incorporating by reference the Agreement, constitutes a
separate instrument of lease.

A.   EQUIPMENT: Subject to the terms and conditions of the Lease. Lessor agrees
to lease to Lessee the Equipment described below (the "Equipment").

<Table>
<Caption>
NUMBER          CAPITALIZED
LESSOR'S COST   MANUFACTURER   SERIAL NUMBERS   YEAR/MODEL AND TYNE OF EQUIPMENT
--------------------------------------------------------------------------------
<S>             <C>            <C>              <C>
SEE EXHIBIT A ATTACHED HERETO AND MADE A PART HEREOF.
</Table>

B. FINANCIAL TERMS

1.   Advance Rent (if any): $32,496.60.
2.   Capitalized Lessor's Cost: $1,025,044.09.
3.   Basic Term (No. of Months): THIRTY SIX (36) Months.
4.   Basic Term Lease Rate Factor: 3.170264.
5.   Basic Term Commencement Date: 12/01/04
6.   Lessee Federal Tax ID No.: 04-3508648.
7.   Last Delivery Date: 11/23/04
8.   Daily Lease Rate Factor: .1057.
9.   Interest Rate: 9.32% per annum.
10.  Option Payment: $1.00

11.  First Termination Date: N/A (-) months after the Basic Term Commencement
     Date.

12.  Interim Rent: For the period from and including the Lease Commencement Date
     to the Basic Term Commencement Date ("INTERIM PERIOD"), Lessee shall pay as
     rent (" INTERIM RENT") for each unit of Equipment, the product of the Daily
     Lease Rate Factor times the Capitalized Lessor's Cost of such unit times
     the number of days in the Interim Period. Interim Rent shall be due on
     Basic Term Commencement Date.

13.  Basic Term Rent. Commencing on 12/01/04 and on the same day of each month
     thereafter (each, a "RENT PAYMENT DATE") during the Basic Term, Lessee
     shall pay as rent ("BASIC TERM RENT") the product of the Basic Term Lease
     Rate Factor times the Capitalized Lessor's Cost of all Equipment on this
     Schedule.

14.  Lessee agrees and acknowledges that the Capitalized Lessor's Cost of the
     Equipment as stated on the Schedule is equal to the fair market value of
     the Equipment on the date hereof.

C.   INTEREST RATE: Interest shall accrue from the Lease Commencement Date
through and including the date of termination of the Lease.

                                       15
<Page>

D.   PROPERTY TAX

PROPERTY TAX NOT APPLICABLE ON EQUIPMENT LOCATED IN MASSACHUSETTS.

     Lessor may notify Lessee (and Lessee agrees to follow such notification)
regarding any changes in property tax reporting and payment responsibilities.

E.   ARTICLE 2A NOTICE

IN ACCORDANCE WITH THE REQUIREMENTS OF ARTICLE 2A OF THE UNIFORM COMMERCIAL CODE
AS ADOPTED IN THE APPLICABLE STATE, LESSOR HEREBY MAKES THE FOLLOWING
DISCLOSURES TO LESSEE PRIOR TO EXECUTION OF THE LEASE, (A) THE PERSON(S)
SUPPLYING THE EQUIPMENT IS VARIOUS (THE "SUPPLIER(S)"), (B) LESSEE IS ENTITLED
TO THE PROMISES AND WARRANTIES, INCLUDING THOSE OF ANY THIRD PARTY, PROVIDED TO
THE LESSOR BY SUPPLIER(S), WHICH IS SUPPLYING THE EQUIPMENT IN CONNECTION WITH
OR AS PART OF THE CONTRACT BY WHICH LESSOR ACQUIRED THE EQUIPMENT AND (C) WITH
RESPECT TO SUCH EQUIPMENT, LESSEE MAY COMMUNICATE WITH SUPPLIER(S) AND RECEIVE
AN ACCURATE AND COMPLETE STATEMENT OF SUCH PROMISES AND WARRANTIES, INCLUDING
ANY DISCLAIMERS AND LIMITATIONS OF THEM OR OF REMEDIES. TO THE EXTENT PERMITTED
BY APPLICABLE LAW, LESSEE HEREBY WAIVES ANY AND ALL RIGHT'S AND REMEDIES
CONFERRED UPON A LESSEE IN ARTICLE 2A AND ANY RIGHTS NOW OR HEREAFTER CONFERRED
BY STATUTE OR OTHERWISE WHICH MAY LIMIT OR MODIFY ANY OF LESSOR'S RIGHTS OR
REMEDIES UNDER THE DEFAULT AND REMEDIES SECTION OF THE AGREEMENT.

F.   STIPULATED LOSS AND TERMINATION VALUE TABLE*

<Table>
<Caption>
             Termination    Stipulated                    Termination     Stipulated
Rental       Value          Loss Value                    Value           Loss Value
Basic        Percentage     Percentage       Rental       Percentage      Percentage
  <S>          <C>            <C>              <C>          <C>              <C>
   1           99.830         103.748          19           53.306           55.803
   2           97.412         101.251          20           50.526           52.945
   3           94.975          98.735          21           47.725           50.064
   4           92.519          96.200          22           44.902           47.163
   5           90.044          93.646          23           42.057           44.239
   6           87.549          91.073          24           39.190           41.293
   7           85.036          88.481          25           36.301           38.325
   8           82.503          85.868          26           33.390           35.334
   9           79.950          83.237          27           30.455           32.321
  10           77.377          80.585          28           27.498           29.285
  11           74.785          77.914          29           24.518           26.226
  12           72.172          75.222          30           21.515           23.144
  13           69.539          72.510          31           18.489           20.039
  14           66.885          69.778          32           15.439           16.910
  15           64.211          67.024          33           12.365           13.757
  16           61.516          64.251          34            9.268           10.581
  17           58.801          61.456          35            6.146            7.380
  18           56.064          58.640          36            3.000            4.155
</Table>

                                       16
<Page>

     *The Stipulated Loss Value or Termination Value for any unit of Equipment
     shall be the Capitalized Lessor's Cost of such unit multiplied by the
     appropriate percentage derived from the above table. In the event that the
     Lease is for any reason extended, then the last percentage figure shown
     above shall control throughout any such extended term.

G.   PAYMENT AUTHORIZATION

     You are hereby irrevocably authorized and directed to deliver and apply the
     proceeds due under this Schedule as follows:

<Table>
<Caption>
     COMPANY NAME                  ADDRESS                              AMOUNT
     ----------------------------------------------------------------------------------
     <S>                           <C>                                  <C>
     Synta Pharmaceuticals Corp.   45 Hartwell Ave. Lexington. MA       $  1,002,924.52

     GE (Advance Rental)           83 Wooster Heights Rd, Danbury, CT   $     22,119.57*
</Table>

     *$12,500 from your Good Faith Deposit will be applied as follows:
     $2,122.97 (Interim Interest)
     $10,377.03 (Balance of Advance Rental)

                                       17
<Page>

     This authorization and direction is given pursuant to the same authority
authorizing the above-mentioned financing.

PURSUANT TO THE PROVISIONS OF THE LEASE, AS IT RELATES TO THIS SCHEDULE, LESSEE
HEREBY CERTIFIES AND WARRANTS THAT (i) ALL EQUIPMENT LISTED ABOVE IS IN GOOD
CONDITION AND APPEARANCE, HAS BEEN DELIVERED AND INSTALLED (IF APPLICABLE) AS OF
THE DATE STATED ABOVE AND IN WORKING ORDER, AND COPIES OF THE BILL(S) OF LADING
OR OTHER DOCUMENTATION ACCEPTABLE TO LESSOR WHICH SHOW THE DATE OF DELIVERY ARE
ATTACHED HERETO; (ii) LESSEE HAS INSPECTED THE EQUIPMENT, AND ALL SUCH TESTING
AS IT DEEMS NECESSARY HAS BEEN PERFORMED BY LESSEE, SUPPLIER OR THE
MANUFACTURER; AND (iii) LESSEE ACCEPTS THE EQUIPMENT FOR ALL PURPOSES OF THE
LEASE AND ALL ATTENDANT DOCUMENTS.

LESSEE DOES FURTHER CERTIFY THAT AS OF THE DATE HEREOF (i) LESSEE IS NOT IN
DEFAULT UNDER THE LEASE; AND (ii) THE REPRESENTATIONS AND WARRANTIES MADE BY
LESSEE PURSUANT TO OR UNDER THE LEASE ARE TRUE AND CORRECT ON THE DATE HEREOF.

     Except as expressly modified hereby, all terms and provisions of the
Agreement shall remain in full force and effect. This Schedule is not binding or
effective with respect to the Agreement or Equipment until executed on behalf of
Lessor and Lessee by authorized representatives of Lessor and Lessee,
respectively.

     IN WITNESS WHEREOF, Lessee and Lessor have caused this Schedule to be
executed by their duly authorized representatives as of the date first above
written.

LESSOR:                                 LESSEE:

GENERAL ELECTRIC CAPITAL CORPORATION    SYNTA PHARMACEUTICALS CORP.


By:    /s/ JOHN EDEL                    By:    /s/ KEITH EHRLICH
       -----------------------------           ---------------------------------

Name:  John Edel                        Name:  Keith Ehrlich
       -----------------------------           ---------------------------------

Title: SVP                              Title: VP of Finance and Administration
       -----------------------------           ---------------------------------


                                       18