EX-4.5



 EXHIBIT 4.5 

SPECIMEN WARRANT CERTIFICATE 
  

			
	 NUMBER
 WB-
	  	[    ] WARRANTS

 (THIS WARRANT WILL BE VOID IF NOT EXERCISED PRIOR TO 5:00 P.M. 

NEW YORK CITY TIME, FIFTEEN MONTHS FROM THE CLOSING DATE OF THE COMPANY’S INITIAL 

PUBLIC OFFERING) 
 CONTRAFECT
CORPORATION 
 CUSIP [            ] 

CLASS B WARRANT 
 THIS WARRANT
CERTIFIES THAT, for value received
                                        , or
registered agents, is the registered holder of a Warrant or Warrants, expiring on a date which is fifteen months from the closing date of the Company’s initial public offering (the “Warrant”), to purchase one-half of a fully paid and
non-assessable share of common stock, par value $0.0001 per share (the “Shares”), of CONTRAFECT CORPORATION, a Delaware corporation (the “Company”), for each Warrant evidenced by this Warrant Certificate. This Warrant Certificate
is subject to and shall be interpreted under the terms and conditions of the Class B Warrant Agreement (as defined below). 
 The Warrant
entitles the holder thereof to purchase from the Company, commencing upon the closing date of the Company’s initial public offering, such number of Shares at the price of $4.00 per full share (the “Warrant Price”), upon surrender of
this Warrant Certificate and payment of the Warrant Price at the office or agency of American Stock Transfer & Trust Company, LLC (the “Warrant Agent”), such payment to be made by check made payable to the Warrant Agent, but only
subject to the conditions set forth herein and in the Warrant Agreement, dated [            ], 2014, between the Company and the Warrant Agent (the “Class B Warrant Agreement”).
In no event shall the registered holder(s) of this Warrant be entitled to receive a net-cash settlement, Shares or other consideration in lieu of physical settlement in Shares of the Company. The Class B Warrant Agreement provides that, upon the
occurrence of certain events, the Warrant Price and the number of Warrant Shares purchasable hereunder, set forth on the face hereof, may be adjusted, subject to certain conditions. The term Warrant Price as used in this Warrant Certificate refers
to the price per Share at which Shares may be purchased at the time the Warrant is exercised. 
 This Warrant will expire on the date first
referenced above if it is not exercised prior to such date by the registered holder pursuant to the terms of the Class B Warrant Agreement or if it is not redeemed by the Company prior to such date. 

No fraction of a Share will be issued upon any exercise of a Warrant. If, upon exercise of a Warrant, a holder would be entitled to receive a
fractional interest in a Share, the Company will, upon exercise, issue or cause to be issued only the largest whole number of Shares issuable on such exercise (and such fraction of a Share will be disregarded). 

Upon any exercise of the Warrant for less than the total number of full Shares provided for herein, there shall be issued to the registered
holder(s) hereof or its assignee(s) a new Warrant Certificate covering the number of Shares for which the Warrant has not been exercised. 

Warrant Certificates, when surrendered at the office or agency of the Warrant Agent by the registered holder(s) hereof in person or by
attorney duly authorized in writing, may be exchanged in the manner and subject to the limitations provided in the Class B Warrant Agreement, but without payment of any service charge, for another Warrant Certificate or Warrant Certificates of like
tenor and evidencing in the aggregate a like number of Warrants. 
 Upon due presentment for registration of transfer of the Warrant
Certificate at the office or agency of the Warrant Agent, a new Warrant Certificate or Warrant Certificates of like tenor and evidencing in the aggregate a like number of Warrants shall be issued to the transferee(s) in exchange for this Warrant
Certificate, subject to the limitations provided in the Class B Warrant Agreement, without charge except for any applicable tax or other governmental charge. 







 The Company and the Warrant Agent may deem and treat the registered holder(s) as the absolute
owner(s) of this Warrant Certificate (notwithstanding any notation of ownership or other writing hereon made by anyone) for the purpose of any exercise hereof, of any distribution to the registered holder(s), and for all other purposes, and neither
the Company nor the Warrant Agent shall be affected by any notice to the contrary. 
 This Warrant does not entitle the registered holder(s)
to any of the rights of a stockholder of the Company. 
 COUNTERSIGNED: 

AMERICAN STOCK TRANSFER & TRUST COMPANY 
 WARRANT AGENT

 BY: 
 AUTHORIZED OFFICER 

DATED: 
 (Signature) 

CHIEF EXECUTIVE OFFICER 
 (Seal) 

(Signature) 
 SECRETARY 







 [REVERSE OF CERTIFICATE] 

SUBSCRIPTION FORM 
 To Be Executed
by the Registered Holder(s) in Order to Exercise Warrants 
 The undersigned Registered Holder(s) irrevocably elect(s) to exercise
                     Warrants represented by this Warrant Certificate, and to purchase the shares of Common Stock issuable upon the exercise of such
Warrants, and requests that Certificates for such shares shall be issued in the name(s) of 
  

	
	  

	(PLEASE TYPE OR PRINT NAME(S) AND ADDRESS)
	
	  

	
	  

	
	  

	(SOCIAL SECURITY OR TAX IDENTIFICATION NUMBER(S))

  

			
	and be delivered to	 	  

		 	(PLEASE PRINT OR TYPE NAME(S) AND ADDRESS)

 and, if such number of Warrants shall not be all the Warrants evidenced by this Warrant Certificate, that a new Warrant
Certificate for the balance of such Warrants be registered in the name of, and delivered to, the Registered Holder(s) at the address(es) stated below: 

Dated: 
  

	
	  

	(SIGNATURE(S))
	
	  

	(ADDRESS(ES))
	
	  

	
	  

	(TAX IDENTIFICATION NUMBER(S))








 ASSIGNMENT 

To Be Executed by the Registered Holder in Order to Assign Warrants 

For Value Received,
                                         hereby
sell(s), assign(s), and transfer(s) unto 
  

			
	  
	  	
	(PLEASE TYPE OR PRINT NAME(S) AND ADDRESS(ES))	  	
		
	  
	  	
		
	  
	  	
		
	  
	  	
	(SOCIAL SECURITY OR TAX IDENTIFICATION NUMBER(S))

  

					
	and to be delivered to	 	  
	 	
		 	(PLEASE PRINT OR TYPE NAME(S) AND ADDRESS(ES))	 	
		
	  
	 	
		
	  
	 	
	(SOCIAL SECURITY OR TAX IDENTIFICATION NUMBER(S))	 	

 of the Warrants represented by this Warrant Certificate, and hereby irrevocably constitute and appoint
                     Attorney to transfer this Warrant Certificate on the books of the Company, with full power of substitution in the premises. 

Dated: 
  

	
	  

	(SIGNATURE(S))

 NOTICE: THE SIGNATURE(S) TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY
PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER. 
 Signature(s) Guaranteed: 

 

			
	By	 	  


 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).