**Exhibit 4.3**

 

[FACEOF CERTIFICATE]

 

[LOGO]

INCORPORATEDUNDER THE LAWS OF THE STATE OF DELAWARE

 
| NUMBER                   | SHARES                               |   |
|--------------------------|--------------------------------------|--------|
| PP                       |                                 |   |
|                     |                                 |   |
| COMMON STOCK             |                                 |   |
| PAR VALUE $.01 PER SHARE | SEE  REVERSE FOR CERTAIN DEFINITIONS |   |
|                     |                                 |   |
| This Certifies That      | CUSIP  739421 40 2                   |   |

 

 

isthe owner of

 

FULLYPAID AND NONASSESSABLE SHARES OF THE COMMON STOCK OF

**PRAECISPHARMACEUTICALS INCORPORATED**

 

*(hereinaftercalled the “Corporation”) transferable on the books of the Corporation by saidowner in person or by duly authorized attorney, upon surrender of thiscertificate properly endorsed. The Corporation will furnish without charge toeach stockholder who so requests, a statement of the powers, designations,preferences and relative, participating, optional, or other special rights ofeach class of stock or series thereof and the qualifications, limitations orrestrictions of such preferences and/or rights. This certificate and the sharesrepresented hereby are issued and shall be held subject to all the provisionsof the Certificate of Incorporation and all amendments thereto, copies of whichare on file at the office of the Transfer Agent, and the holder hereof, byacceptance of this certificate, consents to and agrees to be bound by all ofsaid provisions. This certificate is not valid unless countersigned andregistered by the Transfer Agent and Registrar.*

 

*Witness, the facsimile seal ofthe Corporation and by facsimile the signatures of its duly authorizedofficers.*

 

*Dated:*

 
| /s/ Kevin F. McLaughlin |      | /s/ Edward C. English |   |
|-------------------------|-----------|-----------------------|--------|
| PRESIDENT               | TREASURER |
|                    |      |
| [SEAL]                  |

 

Countersigned and Registered:

AMERICAN STOCK TRANSFER & TRUSTCOMPANY

(NEW YORK, NEW YORK)

Transfer Agent and Registrar

By:

Authorized Signature

 

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[REVERSEOF CERTIFICATE]

 

PRAECISPHARMACEUTICALS INCORPORATED

 

The following abbreviations, when used inthe inscription on the face of this certificate, shall be construed as thoughthey were written out in full according to applicable laws or regulations:

 

TEN COM - as tenants in common

TEN ENT - as tenants by the entireties

JT TEN - as joint tenants with right ofsurvivorship and not as tenants in common

 

UNIF GIFT MIN ACT -         (Cust)         Custodian         (Minor)          underUniform Gifts to Minors Act         (State)

 

Additional abbreviations may also be usedthough not in the above list.

 

For Value Received                                                herebysell, assign and transfer unto

 

PLEASE INSERT SOCIAL SECURITY OR OTHERIDENTIFYING NUMBER OF ASSIGNEE

 

 

(PLEASE PRINT OR TYPEWRITE NAME ANDADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

 

 

 

                                                                                                                                              Sharesof the capital stock represented by the within certificate, and do herebyirrevocably constitute and appoint                                                                                                                                                 Attorneyto transfer the said stock on the books of the within named Corporation withfull power of substitution in the premises.

 

Dated

 

 

NOTICE:

THE SIGNATURE TO THIS ASSIGNMENT MUSTCORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERYPARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.

 
| SIGNATURE(S) GUARANTEED:                                                                                                                                                                                                                                  |   |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|--------|
| THE SIGNATURE(S) MUST BE GUARANTEED BY  AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN  ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE  GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15. |

 

**KEEP THIS CERTIFICATE IN A SAFEPLACE. IF IT IS LOST, STOLEN, MUTILATED OR DESTROYED, THE CORPORATION WILLREQUIRE A BOND OF INDEMNITY AS A CONDITION TO THE ISSUANCE OF A REPLACEMENTCERTIFICATE.**

 

This certificate also evidences andentitles the holder hereof to certain Rights as set forth in the RightsAgreement between PRAECIS PHARMACEUTICALS INCORPORATED (the “Company”) and theRights Agent thereunder (the “Rights Agreement”), the terms of which are herebyincorporated herein by reference and a copy of which is on file at theprincipal offices of the Company. Under certain circumstances, as set forth inthe Rights Agreement, such Rights will be evidenced by separate certificatesand will no longer be evidenced by this certificate. The Company will mail tothe holder of this certificate a copy of the Rights Agreement, as in effect onthe date of mailing, without charge, promptly after receipt of a writtenrequest therefor. Under certain circumstances set forth in the RightsAgreement, Rights issued to, or held by, any Person who is, was or becomes anAcquiring Person or any Affiliate or Associate thereof (as such terms aredefined in the Rights Agreement), whether currently held by or on behalf ofsuch Person or by any subsequent holder, may become null and void.

 

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