Exhibit 10.9.1   GE Commercial Finance Healthcare Financial Services Life Science Finance 83 Wooster Heights Road, 5th
Floor Danbury, CT  06810 203-205-5216 / FAX: 203-205-2183    June 28, 2007   CONFIDENTIAL CAPITAL (QUASI) LEASE PROPOSAL FOR:  Synta Pharmaceuticals Corp.
    Submitted By:William B. Stickle


Synta
  Pharmaceuticals Corp.
  Mr. Keith Ehrlich Chief Financial Officer Synta Pharmaceuticals Corp. 45 Hartwell Avenue Lexington, MA  02421  Dear Mr. Ehrlich:  General
Electric Capital Corporation (GE Capital) has reviewed the information
provided by you in connection with the requested financing for Synta
Pharmaceuticals Corp (referred to as Synta Pharmaceuticals or the Company).
 Based on the review to date and subject
to the timely receipt of a signed copy of this proposal letter as indicated
below, GE Capital is pleased to consider arranging and providing a lease
financing up to a maximum aggregate exposure to GE Capital of $6,000,000 (the Financing)
as outlined in the attached Term Sheet incorporated herein by reference, subject
to the general terms and conditions in this proposal letter and the Term Sheet.  GE
Capital is one of the largest and most diversified financial services companies
in the world with assets exceeding $300 billion and operations in over 45
countries.  We have been actively
providing equipment financing for Life Science companies for over a decade and
it is our privilege to be a financial partner to hundreds of Life Science
companies.  This
proposal letter, including the attached Term Sheet (together, the Proposal),
is being provided to the Company on a confidential basis and is merely an indication
of interest regarding the Financing transaction on the general terms and
conditions outlined below and should not be construed as a commitment.  GE Capital may change the terms of this
Proposal or cease future consideration of the Financing at any time in its sole
discretion.  The attached Term Sheet
summarizes only the principal terms and conditions under which the proposed
Financing will be considered and does not purport to set forth all of the terms
and conditions applicable to such Financing, which terms and conditions will be
fully contained in the final documentation.  The
Company may not use this Proposal to solicit other offers or to modify,
renegotiate or otherwise improve the terms and conditions of any other offer
heretofore or hereafter received by the Company but is not restricted from
making any disclosure or dissemination of the United States federal income tax structure
or aspects of the transactions contemplated by this proposal or any documents
executed pursuant to this Proposal.  Further,
each of GE Capital and the Company acknowledges that it has no proprietary
rights to any United States federal income tax elements or structure of this
Proposal.  In addition, the Company shall
not, except as required by law, use the name of, or refer to GE Capital, in any
correspondence, discussions, advertisement, press release or disclosure made in
connection with the Financing without the prior written consent of GE Capital.  By
signing below, the Company acknowledges the terms and conditions of this
Proposal and agrees to pay to GE Capital a Good Faith Deposit of $20,000
(Deposit).  Upon receipt of the executed
Proposal and accompanying Deposit, GE Capital shall commence the investment and
credit approval process.  Upon acceptance
by GE Capital the Good Faith Deposit will be   2


Synta
  Pharmaceuticals Corp.
  applied as follows: (i) $10,000 earned
by GE Capital as a non-recurring upfront fee, and (ii) the remainder to the
initial payment(s) with any unutilized Deposit remaining at the end of the
Anticipated Funding Period to be retained by GE Capital as a non-utilization
fee.  In the event the funded transaction
materially differs from the terms of this Proposal, the documentation charge may
be adjusted to correspond with GE Capitals actual out-of-pocket expenses.  The Deposit is not refundable except in the
event that the transaction represented by this Proposal and any amendment to it
is not approved by GE Capital.  In such
case, GE Capital shall promptly return the Deposit (less the cost of credit
verification and investigation and any out of pocket expenses incurred such as appraisal
fees, legal fees, etc.).  Before funding
can take place, all proper documentation of title and UCC releases from other
lenders shall be in place and approved by GE Capital.  We thank you for your consideration and look
forward to working with you toward completing this transaction.  By
signing this Proposal Letter, regardless of whether the Financing is approved
or closes, the Company agrees to pay upon demand to GE Capital all fees and
expenses (including but not limited to all costs and fees of external legal
counsel, environmental consultants, appraisers, inspectors, auditors and other
consultants and advisors selected by GEHFS, due diligence reports, UCC, tax and
judgment lien search and filing costs, escrow costs (if applicable), recording
and transfer fees and taxes, title charges and survey costs and the allocated cost
of internal legal counsel) incurred in connection with this Proposal Letter and
the Financing (and the negotiation, documentation and closing thereof).  I
would appreciate the opportunity to discuss this proposal with you at your
earliest convenience.  Please do not hesitate
to contact me at 203-205-5216 if you have any questions or if I may be of
further assistance.  Sincerely,/s/ William B. StickleWilliam B. Stickle    PROPOSAL ACCEPTED BY:  Synta Pharmaceuticals Corp.  Name:
  /s/ Keith EhrlichTitle:
  CFODate:
  6/29/07Federal Tax ID#:
  04-3508648Email Address:
  kehrlich@syntapharma.com  3


Synta
  Pharmaceuticals Corp.
  Contact Name for
  Inspection:
  Jerry Di CeccaPhone #:
  781-541-7268  4


Synta
  Pharmaceuticals Corp.
  Term SheetTransaction:
  Capital Lease (Quasi)Lessee:
  Synta Pharmaceuticals
  Corp.Lessor:
  General Electric Capital
  Corporation its affiliates or its assignee (GE Capital)Lease Line Amount:
  Up to an aggregate
  exposure to GE Capital of $6,000,000.Lease Term and Payment:
  Laboratory/Manufacturing equipment:48 payments
  per month in advance at 2.566600% per thousand dollars cost of Equipment (the
  Payment Factor), plus applicable taxes for each lease schedule.All other equipment:36 payments
  per month in advance at 3.248560% per thousand dollars cost of Equipment (the
  Payment Factor), plus applicable taxes for each lease schedule.Anticipated Funding Period:
  June 2007 through June
  2008.Line Mechanics:
  Equipment with invoice
  dates older than 90 days will be subject to appropriate discount.Amortization begins on the
  start date, which is the first day of the month following the funding date.
  Interim rent will be charged for any period between the funding date and the
  start date.Collateral:
  A fully perfected first
  priority security interest in various Equipment, as detailed in the attached
  Addendum A.  All Equipment must be
  acceptable to GE Capital and located at Company owned or leased facilities
  within the continental United Sates. All collateral shall be free and clear
  of all liens, claims and encumbrances.End of Lease Purchase Option:
  At the end of the
  scheduled term, the Lessee may purchase the leased equipment for $1.00.Other Conditions:
  All other terms and
  conditions that presently exist shall continue to apply.
   5


Synta
  Pharmaceuticals Corp.
  GENERAL
TERMS AND CONDITIONS  Our proposal contains the
following provisions and the Lease Payment Factor we propose are specifically
based upon these provisions and our assumptions.  1.Purchase of Equipment:
Lessee would submit its order for the equipment to the vendor.  Lessor would take an assignment of Lessees
purchase order.  Such assignment would be
conditioned upon the leasing of the Equipment by Lessee from Lessor.  Lessee understands that any Equipment
delivered after the Last Delivery Date would not be covered by this proposal.  2.Net Lease:
The proposed lease would be a net lease. 
Without limiting the generality of the foregoing, Lessee would be
responsible for all expenses, maintenance, insurance and taxes relating to the
purchase, lease, possession and use of the Equipment.  3.Maintenance and Insurance:
Lessee would bear all risk of loss or damage to the Equipment.  Lessee would be responsible to keep the Equipment
insured with companies acceptable to Lessor and for such amounts required by
Lessor, including, but not limited to, insurance for damage to or loss of the
Equipment and liability coverage.  All
such insurance policies must be satisfactory to Lessor.  4.Warranties:
Lessor would lease the Equipment to Lessee on an AS IS BASIS.  However, Lessor would assign to Lessee all
warranties, guarantees and services provided by the manufacturer or vendor (to
the extent that they are assignable).  5.Documentation and
Transactional Costs: Standard GE CAPITAL Master Lease and Lease
Schedule for this type of equipment (Lease Documents).  Any changes to the Lease Documents must be
approved by GE CAPITAL legal counsel. 
Lessee will be responsible for all costs associated with the transaction
including any appraisal costs, legal fees and inspection expenses.  6.Indexing:
The Payment Factor and corresponding Lease payments are based on the Federal
Reserves 3 and 4 year Treasury Constant Maturities Rate (H.15/ Treasury
Rate) as of 06/26/2007 currently 4.95 and 4.97 respectively, and will be
adjusted effective as of the date of funding of any Financing to reflect any
increases in the Treasury Rate.  7.Electronic Payment System:
GE Capitals standard payment collection method is through an electronic
payment system.  An enrollment form will
be provided with the Lease Documents.  8.Confidentiality:
This proposal letter is being provided to the Company on a confidential
basis.  Except as required by law,
neither this proposal nor its contents may be disclosed, except to individuals
who are the Companys officers, employees or advisors who have a need to know
of such matters and then only on the condition that such matters remain
confidential.  In addition, none of such
persons shall, except as required by law, use the  6


Synta
  Pharmaceuticals Corp.
  name of, or refer to GE Capital, in any
correspondence, discussions, advertisement, press release or disclosure made in
connection with the Financing without the prior written consent of GE Capital.  9.Expiration:
This proposal will expire 06/30/2007, if not accepted prior to that date.  10.Other
Conditions: GE Capitals agreement to fund the proposed
transaction remains subject to and would be preceded by completion of a legal
and business due diligence, as well as collateral and credit review and
analysis, all with results satisfactory to GE Capital and the closing of an
initial funding under such transaction would be conditioned upon the prior
execution and delivery of final Lease Documents and satisfaction of all
conditions precedent acceptable to GE Capital and its counsel and no material
adverse change in the business condition or prospects of the Company (Material
Adverse Change).  For transactions that
contemplate more than one funding, GE Capitals obligation to make each such
subsequent funding would be subject to confirmation that no default has
occurred and is continuing under the Lease Documents, that all representations
and warranties of the Company in the Lease Documents continue to be true and
correct and that no Material Adverse Change has occurred since the prior
funding.  If a commitment were to be
given it would be subject to and preceded by a completion of a legal and
business due diligence, as well as collateral and credit review and analysis,
all with results satisfactory to GE Capital and the closing of any Financing
would be conditioned upon the prior execution and delivery of final legal documentation
and all conditions precedent acceptable to GE Capital and its counsel and
confirmation that no Material Adverse Change has occurred since the issuance of
such commitment.   7


Synta
  Pharmaceuticals Corp.
  Addendum
A  Expected Equipment Composition  Equipment Class
  
  Concentration RequirementLaboratory &
  scientific equipment:
  
  Minimum of 72.5%Lab and office furniture, office equipment,
  computers, networking equipment, &
  similar:
  
  Maximum of 20.0%Soft costs (leaseholds, software,
  tax, freight & similar):
  
  Maximum of 7.5%Total
  
  100%
   8