Exhibit
10.56


MOMENTA PHARMACEUTICALS, INC.


Restricted
Stock Agreement

Granted Under 2004 Stock Incentive Plan, as amended


AGREEMENT
made on December 15, 2006 between Momenta Pharmaceuticals, Inc., a Delaware  corporation (the “Company”), and John E. Bishop (the
“Participant”).


For
valuable consideration, receipt of which is acknowledged, the parties hereto
agree as follows:


1.             Issuance of Shares.


The
Company hereby issues to the Participant, subject to the terms and conditions
set forth in this Agreement and in the Company’s 2004 Stock Incentive Plan, as
amended (the “Plan”), 15,000 shares (the “Shares”) of common
stock, $0.0001 par value per share, of the Company (“Common Stock”). The
Shares will be held in book entry by the Company’s transfer agent in the name
of the Participant for that number of Shares issued to the Participant. The
Participant agrees that the Shares shall be subject to the forfeiture
provisions set forth in Section 2 of this Agreement and the restrictions
on transfer set forth in Section 3 of this Agreement.


2.             Vesting.


2.1           Unless otherwise provided in this Agreement
or the Plan, in the event that the Participant ceases to be employed by the
Company on or before December 14, 2010, for any reason or no reason, with or
without cause, all of the Unvested Shares (as defined below) will be
immediately and automatically forfeited and returned to the Company for no
consideration effective as of the date of termination of employment. The
Participant will have no further rights with respect to any Shares that are so
forfeited. “Unvested Shares” means the total number of Shares multiplied
by the Applicable Percentage. The “Applicable Percentage” shall be
(i) 100% during the 12-month period ending on December 15, 2007, (ii) 75%
less 6.25% for each three-month period from and after December 15, 2007, and
(iii) zero on or after December 15, 2010.


2.2           For
purposes of this Agreement, employment with the Company shall include
employment with a parent or subsidiary of the Company, or any successor to the
Company.


3.             Restrictions on Transfer.


3.1           The
Participant shall not sell, assign, transfer, pledge, hypothecate or otherwise
dispose of, by operation of law or otherwise (collectively “transfer”)
any Shares, or any interest therein, until such Shares have vested, except that
the Participant may transfer such Shares (i) to or for the benefit of any
spouse, children, parents, uncles, aunts, siblings, grandchildren and any other
relatives approved by the Board of Directors (collectively, “Approved
Relatives”) or to a trust established solely for the benefit of the
Participant and/or Approved Relatives, provided that such Shares shall
remain subject to this Agreement (including without limitation the restrictions
on transfer set forth in this Section 3 and the forfeiture provisions contained
in Section 2) and such permitted transferee shall, as a condition to such
transfer, deliver to the Company a written instrument confirming that such
transferee shall be bound by all of the terms and conditions of this Agreement or
(ii) as part of the sale of all or substantially all of the shares of capital
stock of the Company (including pursuant to a merger or consolidation), provided
that, in accordance with the Plan and except as otherwise provided herein, the
securities or other property received by the Participant in connection with
such transaction shall remain subject to this Agreement.


3.2           The
Company shall not be required (i) to transfer on its books any of the Shares
which have been transferred in violation of any of the provisions set forth in
this Agreement or (ii) to treat as owner of such Shares or to pay dividends to
any transferee to whom such Shares have been transferred in violation of any of
the provisions of this Agreement.


4.             Restrictive Legends.


All
Shares subject to this Agreement subject to the following restriction, in
addition to any other legends that may be required under federal or state
securities laws:











 


“The
shares of stock represented by this certificate are subject to forfeiture
provisions and restrictions on transfer set forth in a certain Restricted Stock
Agreement between the corporation and the registered owner of these shares (or
his predecessor in interest), and such Agreement is available for inspection
without charge at the office of the Secretary of the corporation.”


5.             Provisions of the Plan.


This
Agreement is subject to the provisions of the Plan, a copy of which is
furnished to the Participant with this Agreement. Capitalized terms used, but
not otherwise defined, herein shall have the meaning given to them in the Plan.


6.             Withholding Taxes; Section 83(b) Election.


6.1           The Participant acknowledges and agrees that
the Company has the right to deduct from payments of any kind otherwise due to
the Participant any federal, state, local or other taxes of any kind required
by law to be withheld with respect to the issuance of the Shares to the
Participant or the lapse of the forfeiture provisions. For so long as the
Common Stock is registered under the Exchange Act, the Participant may
satisfy such tax obligations in whole or in part by delivery of shares of
Common Stock, including shares retained from this award, valued at their Fair
Market Value; provided, however, that (i) the total tax
withholding where stock is being used to satisfy such tax obligations cannot
exceed the Company’s minimum statutory withholding obligations (based on
minimum statutory withholding rates for federal and state tax purposes,
including payroll taxes, that are applicable to such supplemental taxable
income) and (ii) satisfaction of such tax obligations through shares of the
Company’s Common Stock, including Shares retained from this award, may only be
authorized by the Company’s Compensation Committee in its sole discretion at
any time prior to the occurrence of a vesting date (whereby such Committee may
adopt a resolution permitting the Participant to satisfy his tax withholding
obligation through the surrender of shares of the Company’s Common Stock,
including a portion of the Shares the vesting of which gives rise to the
withholding obligations). Shares surrendered to satisfy tax withholding
requirements cannot be subject to any repurchase, forfeiture, unfulfilled
vesting or other similar requirements.


6.2           The Participant has reviewed with the
Participant’s own tax advisors the federal, state, local and other tax
consequences of this investment and the transactions contemplated by this
Agreement. The Participant is relying solely on such advisors and not on any
statements or representations of the Company or any of its agents. The
Participant understands that the Participant (and not the Company) shall be
responsible for the Participant’s own tax liability that may arise as a result
of this investment and the transactions contemplated by this Agreement.


THE PARTICIPANT AGREES NOT TO FILE AN ELECTION UNDER SECTION 83(B) OF
THE INTERNAL REVENUE CODE WITH RESPECT TO THE ISSUANCE OF THE SHARES.


7.             Miscellaneous.


7.1           No Rights to Employment.  The
Participant acknowledges and agrees that the vesting of the Shares pursuant to
Section 2 hereof is earned only by continuing service as an employee of the
Company (not through the act of being hired or being granted the Shares
hereunder). The Participant further acknowledges and agrees that the
transactions contemplated hereunder and the vesting schedule set forth herein
do not constitute an express or implied promise of continued engagement as an
employee for the vesting period, for any period, or at all.


7.2           Severability.  The
invalidity or unenforceability of any provision of this Agreement shall not
affect the validity or enforceability of any other provision of this Agreement,
and each other provision of this Agreement shall be severable and enforceable
to the extent permitted by law.


7.3           Waiver.  Any provision for the benefit
of the Company contained in this Agreement may be waived, either generally or
in any particular instance, by the Board of Directors of the Company.


7.4           Binding Effect.  This
Agreement shall be binding upon and inure to the benefit of the Company and the
Participant and their respective heirs, executors, administrators, legal
representatives, successors and assigns, subject to the restrictions on
transfer set forth in Section 3 of this Agreement.











7.5           Notice.  Each notice relating to this
Agreement shall be in writing and delivered in person or by first class mail,
postage prepaid, to the address as hereinafter provided. Each notice shall be
deemed to have been given on the date it is received. Each notice to the
Company shall be addressed to it at its offices at 675 West Kendall Street,
Cambridge, Massachusetts 02142 (Attention: Vice President, Legal Affairs). Each
notice to the Participant shall be addressed to the Participant at the
Participant’s last known address.


7.6           Pronouns.  Whenever the context may require,
any pronouns used in this Agreement shall include the corresponding masculine,
feminine or neuter forms, and the singular form of nouns and pronouns shall
include the plural, and vice versa.


7.7           Entire Agreement.  This
Agreement and the Plan constitute the entire agreement between the parties, and
supersede all prior agreements and understandings, relating to the subject
matter of this Agreement.


7.8           Amendment.  This Agreement may be amended
or modified only by a written instrument executed by both the Company and the
Participant.


7.9           Governing Law.  This
Agreement shall be construed, interpreted and enforced in accordance with the
internal laws of the State of Delaware without regard to any applicable
conflicts of laws.


7.10         Interpretation.  The
interpretation and construction of any terms or conditions of the Plan, or of
this Agreement or other matters related to the Plan by the Compensation
Committee of the Board of Directors of the Company shall be final and
conclusive.


7.11         Participant’s Acknowledgments.  The
Participant acknowledges that he: (i) has read this Agreement; (ii) has been
represented in the preparation, negotiation, and execution of this Agreement by
legal counsel of the Participant’s own choice or has voluntarily declined to
seek such counsel; (iii) understands the terms and consequences of this
Agreement; (iv) is fully aware of the legal and binding effect of this
Agreement; and (v) understands that the law firm of Wilmer Cutler Pickering
Hale and Dorr LLP is acting as counsel to the Company in connection with the
transactions contemplated by the Agreement, and is not acting as counsel for
the Participant.


7.12         Delivery
of Certificates.  The Participant may request that the Company
deliver the Shares in certificated form with respect to any Shares that have
ceased to be subject to forfeiture pursuant to Section 2.


7.13         No
Deferral.  Notwithstanding anything herein to the
contrary, neither the Company nor the Participant may defer the delivery of the
Shares.











IN
WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day
and year first above written.


	
  

  	
   

  	
  MOMENTA PHARMACEUTICALS, INC.

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Richard P.
  Shea

  	
   

  
	
   

  	
   

  	
   

  	
  Richard P. Shea

  
	
   

  	
   

  	
   

  	
  Vice President,
  Chief Financial Officer

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  /s/ John E.
  Bishop

  	
   

  
	
   

  	
   

  	
  John E. Bishop