Exhibit 4.2



 Exhibit 4.2 

NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE “SECURITIES ACT”), OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE
SECURITIES ACT OR (B) AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS AS EVIDENCED BY A LEGAL OPINION
OF COUNSEL OR OTHER EVIDENCE REASONABLY SATISFACTORY TO THE COMPANY OR (II) UNLESS SOLD PURSUANT TO RULE 144 UNDER THE SECURITIES ACT. 

PLACEMENT AGENT’S WARRANT 

CONTRAFECT CORPORATION 
  

			
	Warrant Shares: [                ]		Issuance Date: June [    ], 2015

 THIS PLACEMENT AGENT’S WARRANT (the “Warrant”) certifies that, for value received,
[            ] or its designees or assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth,
at any time on or after the date of this Warrant (the “Initial Exercise Date”) and on or prior to the close of business on the five (5) year anniversary of the Initial Exercise Date (the “Termination Date”) but
not thereafter, to subscribe for and purchase from ContraFect Corporation, a Delaware corporation (the “Company”), up to [                ] shares (as
subject to adjustment hereunder, the “Warrant Shares”) of Common Stock. The purchase price of one share of Common Stock under this Warrant shall be equal to the Exercise Price, as defined in Section 2(b). 

Section 1. Definitions. Capitalized terms used and not otherwise defined herein shall have the meanings set forth in the Securities
Purchase Agreements (the “Agreements”), each dated June [    ], 2015, between the Company and each Purchaser identified on the signature pages thereto. 

Section 2. Exercise. 

(a) Exercise of the purchase rights represented by this Warrant may be made, in whole or in part, at any time or times on or after the
Initial Exercise Date and on or before the Termination Date by delivery to the Company (or such other office or agency of the Company as it may designate by notice in writing to the registered Holder at the address of the Holder appearing on the
books of the Company) of a duly executed facsimile copy of the Notice of Exercise form annexed hereto. Within three (3) Trading Days following the date the Notice of Exercise is delivered, the Holder shall pay to the Company the aggregate
Exercise Price for the shares thereby purchased by wire transfer or cashier’s check drawn on a United States bank unless the cashless exercise procedure specified in Section 2(c) below is specified in the applicable Notice of Exercise.
Notwithstanding anything herein to the contrary, the Holder shall not be required to physically surrender this Warrant to the Company until the Holder has purchased all of the Warrant Shares available hereunder and the Warrant has been exercised in
full, in which case the Holder shall surrender this Warrant to the Company for cancellation within three (3) Trading Days of the date the final Notice of Exercise is delivered to the Company. Partial exercises of this Warrant resulting in
purchases of a portion of the total number of Warrant Shares available hereunder shall have the effect of lowering the outstanding number of Warrant Shares purchasable hereunder in an amount equal to the applicable number of Warrant Shares
purchased. The Holder and the Company shall maintain records showing the number of Warrant Shares purchased and the date of such purchases; provided that the records of the Company, absent manifest error, will be conclusive with respect to the
number of Warrant Shares purchasable from time to time hereunder. The Company shall deliver any objection to any Notice of Exercise form within two (2) Business Days of receipt of such notice. The Holder and any assignee, by acceptance of
this Warrant, acknowledge and agree that, by reason of the provisions of this paragraph, following the purchase of a portion of the Warrant Shares hereunder, the number of Warrant Shares available for purchase hereunder at any given time may be less
than the amount stated on the face hereof. 







 (b) Exercise Price. The exercise price per share of the Common Stock under this
Warrant shall be $4.66, subject to adjustment hereunder (the “Exercise Price”). Except as otherwise permitted in accordance with Section 2(c), this Warrant may only be exercised by means of payment by wire transfer or
cashier’s check drawn on a United States bank. 
 (c) Cashless Exercise. This Warrant may at the option of the Holder be
exercised, in whole or in part, by means of a “cashless exercise” in which the Holder shall be entitled to receive a number of Warrant Shares equal to the quotient obtained by dividing [(A-B) (X)] by (A), where: 

(A) = the VWAP on the trading day immediately preceding the date on which Holder elects to exercise this Warrant by means of a “cashless exercise,”
as set forth in the applicable Notice of Exercise; 
 (B) = the Exercise Price of this Warrant, as adjusted hereunder; and 

(X) = the number of Warrant Shares that would be issuable upon exercise of this Warrant in accordance with the terms of this Warrant if such exercise were by
means of a cash exercise rather than a cashless exercise. 
 “VWAP” means, for any date, the price determined by the first of the following
clauses that applies: (a) if the Common Stock is then listed or quoted on a “national securities exchange” (as such term is defined under Section 6(a) of the Securities Exchange Act of 1934, as amended (the “Exchange
Act”)), the daily volume weighted average price of the Common Stock for such date (or the nearest preceding date) on the national securities exchange on which the Common Stock is then listed or quoted as reported by Bloomberg L.P.
(“Bloomberg”) (based on a trading day from 9:30 a.m. (New York City time) to 4:02 p.m. (New York City time)), (b) if the Common Stock is not then listed or quoted for trading on a national securities exchange and if prices for
the Common Stock are then reported on the OTC Bulletin Board, the volume weighted average price of the Common Stock for such date (or the nearest preceding date) on the OTC Bulletin Board, (c) if the Common Stock is not then listed or quoted
for trading on the OTC Bulletin Board and if prices for the Common Stock are then reported in the “Pink Sheets” published by Pink OTC Markets, Inc. (or a similar organization or agency succeeding to its functions of reporting prices), the
most recent bid price per share of the Common Stock so reported, or (d) in all other cases, the fair market value of a share of Common Stock as determined by an independent appraiser selected in good faith by the Board of Directors of the
Company and reasonably acceptable to the Holder, the fees and expenses of which shall be paid by the Company. 
 (d) Mechanics of
Exercise. 
 (i) Delivery of Warrant Shares Upon Exercise. The Company shall use best efforts to cause the Warrant Shares
purchased (including pursuant to Section 2(c)) hereunder to be transmitted by the Transfer Agent to the Holder by crediting the account of the Holder’s prime broker with The Depository Trust Company (“DTC”) through its
Deposit or Withdrawal at Custodian system (“DWAC”) if the Company is then a participant in such system and either (A) there is an effective registration statement permitting the issuance of the Warrant Shares or resale of the
Warrant Shares or (B) the Warrant Shares are eligible for resale by the Holder without volume or manner of sale limitations pursuant to Rule 144 under the Securities Act (“Rule 144”), and otherwise by physical delivery to the
address specified by the Holder in the Notice of Exercise by the date that is five (5) Trading Days after the latest of (A) the delivery to the Company of the Notice of Exercise, (B) surrender of this Warrant (if required) and
(C) payment of the aggregate Exercise Price as set forth above (including by cashless exercise) (such date, the “Warrant Share Delivery Date”). The Warrant Shares shall be deemed to have been issued, and Holder or any other
person so designated to be named therein shall be deemed to have become a holder of record of such shares for all purposes, as of the date the Warrant has been exercised, with payment to the Company of the Exercise Price (or by cashless exercise)
and all taxes required to be paid by the Holder, if any, pursuant to Section 2(d)(v) prior to the issuance of such shares, having been paid. 

(ii) Delivery of New Warrants Upon Exercise. If this Warrant shall have been exercised in part, the Company shall, at the request
of a Holder and upon surrender of this Warrant certificate, at the time of delivery of the Warrant Shares, deliver to the Holder a new Warrant evidencing the rights of the Holder to purchase the unpurchased Warrant Shares called for by this Warrant,
which new Warrant shall in all other respects be identical with this Warrant. 
 (iii) Rescission Rights. If the Company fails
to cause its transfer agent to transmit to the Holder the Warrant Shares pursuant to Section 2(d)(i) by the Warrant Share Delivery Date, then the Holder will have the right to rescind such exercise. 







 (iv) No Fractional Shares or Scrip. No fractional shares or scrip representing
fractional shares shall be issued upon the exercise of this Warrant. As to any fraction of a share which the Holder would otherwise be entitled to purchase upon such exercise, the Company shall, at its election, either pay a cash adjustment in
respect of such final fraction in an amount equal to such fraction multiplied by the Exercise Price or round up to the next whole share. 

(v) Charges, Taxes and Expenses. Issuance of Warrant Shares shall be made without charge to the Holder for any issue or transfer
tax or other incidental expense in respect of the issuance of such Warrant Shares, all of which taxes and expenses shall be paid by the Company, and such Warrant Shares shall be issued in the name of the Holder or in such name or names as may be
directed by the Holder; provided, however, that, in the event Warrant Shares are to be issued in a name other than the name of the Holder, this Warrant when surrendered for exercise shall be accompanied by the Assignment Form attached
hereto duly executed by the Holder and the Company may require, as a condition thereto, the payment of a sum sufficient to reimburse it for any transfer tax incidental thereto. The Company shall pay all Transfer Agent fees required for same-day
processing of any Notice of Exercise. 
 (vi) Closing of Books. The Company will not close its stockholder books or records in
any manner which prevents the timely exercise of this Warrant, pursuant to the terms hereof. 
 (e) Holder’s Exercise
Limitations. The Company shall not effect any exercise of this Warrant, and a Holder shall not have the right to exercise any portion of this Warrant, pursuant to Section 2 of this Warrant or otherwise, to the extent that after giving
effect to such issuance after exercise as set forth on the applicable Notice of Exercise, the Holder (together with the Holder’s Affiliates and any other Persons acting as a group together with the Holder or any of the Holder’s
Affiliates), would beneficially own in excess of the Beneficial Ownership Limitation (as defined below). For purposes of the foregoing sentence, the number of shares of Common Stock beneficially owned by the Holder and its Affiliates shall
include the number of shares of Common Stock issuable upon exercise of this Warrant with respect to which such determination is being made, but shall exclude the number of shares of Common Stock which would be issuable upon (i) exercise of the
remaining, nonexercised portion of this Warrant beneficially owned by the Holder or any of its Affiliates and (ii) exercise or conversion of the unexercised or nonconverted portion of any other securities of the Company (including, without
limitation, any other Common Stock Equivalents) subject to a limitation on conversion or exercise analogous to the limitation contained herein beneficially owned by the Holder or any of its Affiliates. Except as set forth in the preceding
sentence, for purposes of this Section 2(e), beneficial ownership shall be calculated in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder, it being acknowledged by the Holder that the
Company is not representing to the Holder that such calculation is in compliance with Section 13(d) of the Exchange Act and the Holder is solely responsible for any schedules required to be filed in accordance therewith. To the extent that the
limitation contained in this Section 2(e) applies, the determination of whether this Warrant is exercisable (in relation to other securities owned by the Holder together with any Affiliates) and of which portion of this Warrant is exercisable
shall be in the sole discretion of the Holder, and the submission of a Notice of Exercise shall be deemed to be the Holder’s determination of whether, and representation and certification to the Company that, this Warrant is exercisable (in
relation to other securities owned by the Holder together with any Affiliates) and of which portion of this Warrant is exercisable, in each case subject to the Beneficial Ownership Limitation, and the Company shall have no obligation to verify or
confirm the accuracy of such determination. In addition, a determination as to any group status as contemplated above shall be determined in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder.
For purposes of this Section 2(e), in determining the number of outstanding shares of Common Stock, a Holder may rely on the number of outstanding shares of Common Stock as reflected in (A) the Company’s most recent periodic or annual
report filed with the Commission, as the case may be, (B) a more recent public announcement by the Company or (C) a more recent written notice by the Company or the Transfer Agent setting forth the number of shares of Common Stock
outstanding. Upon the written or oral request of a Holder, the Company shall within two (2) Trading Days confirm orally and in writing to the Holder the number of shares of Common Stock then outstanding. In any case, the number of
outstanding shares of Common Stock shall be determined after giving effect to the conversion or exercise of securities of the Company, including this Warrant, by the Holder or its Affiliates since the date as of which such number of outstanding
shares of Common Stock was reported. The “Beneficial Ownership Limitation” shall be 4.99% of the number of shares of Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock issuable upon
exercise of this Warrant. The Holder, upon not less than 61 days’ prior notice to the Company, may increase or decrease the 







 
Beneficial Ownership Limitation provisions of this Section 2(e), provided that the Beneficial Ownership Limitation in no event exceeds 9.99% of the number of shares of the Common Stock
outstanding immediately after giving effect to the issuance of shares of Common Stock upon exercise of this Warrant held by the Holder and the provisions of this Section 2(e) shall continue to apply. Any such increase or decrease will not be
effective until the 61st day after such notice is delivered to the Company. The term “Common Stock Equivalents” shall mean any securities of the Company which would entitle the holder thereof to acquire at any time Common Stock,
including, without limitation, any debt, preferred stock, right, option, warrant or other instrument that is at any time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to receive, Common Stock. The
provisions of this paragraph shall be construed and implemented in a manner otherwise than in strict conformity with the terms of this Section 2(e) to correct this paragraph (or any portion hereof) which may be defective or inconsistent with
the intended Beneficial Ownership Limitation herein contained or to make changes or supplements necessary or desirable to properly give effect to such limitation. The limitations contained in this paragraph shall apply to a successor holder of this
Warrant. 
 Section 3. Certain Adjustments. 

(a) Stock Dividends and Splits. If the Company, at any time while this Warrant is outstanding: (i) pays a stock dividend or
otherwise makes a distribution or distributions on shares of its Common Stock or any other equity or equity equivalent securities payable in shares of Common Stock (which, for avoidance of doubt, shall not include any shares of Common Stock issued
by the Company upon exercise of this Warrant), (ii) subdivides outstanding shares of Common Stock into a larger number of shares, (iii) combines (including by way of reverse stock split) outstanding shares of Common Stock into a smaller
number of shares, or (iv) issues by reclassification of shares of the Common Stock any shares of capital stock of the Company, then in each case the Exercise Price shall be multiplied by a fraction of which the numerator shall be the number of
shares of Common Stock (excluding treasury shares, if any) outstanding immediately before such event and of which the denominator shall be the number of shares of Common Stock outstanding immediately after such event, and the number of shares
issuable upon exercise of this Warrant shall be proportionately adjusted such that the aggregate Exercise Price of this Warrant shall remain unchanged. Any adjustment made pursuant to this Section 3(a) shall become effective immediately after
the record date for the determination of stockholders entitled to receive such dividend or distribution and shall become effective immediately after the effective date in the case of a subdivision, combination or re-classification. 

(b) Subsequent Rights Offerings. In addition to any adjustments pursuant to Section 3(a) above, if at any time during which
this Warrant is outstanding the Company grants, issues or sells any Common Stock Equivalents or other rights to purchase stock, warrants, securities or other property pro rata to all record holders of shares of Common Stock (the “Purchase
Rights”), then the Holder will be entitled to acquire, upon the terms applicable to such Purchase Rights, the aggregate Purchase Rights which the Holder could have acquired if the Holder had held the number of shares of Common Stock
acquirable upon complete exercise of this Warrant (without regard to any limitations on exercise hereof, including without limitation, the Beneficial Ownership Limitation) immediately before the date on which a record is taken for the grant,
issuance or sale of such Purchase Rights, or, if no such record is taken, the date as of which the record holders of shares of Common Stock are to be determined for the grant, issue or sale of such Purchase Rights (provided, however, to the extent
that the Holder’s right to participate in any such Purchase Right would result in the Holder exceeding the Beneficial Ownership Limitation, then the Holder shall not be entitled to participate in such Purchase Right to such extent (or
beneficial ownership of such shares of Common Stock as a result of such Purchase Right to such extent) and such Purchase Right to such extent shall be held in abeyance for the Holder until such time, if ever, as its right thereto would not result in
the Holder exceeding the Beneficial Ownership Limitation). The provisions of this Section 3(b) will not apply to any grant, issuance or sale of Common Stock Equivalents or other rights to purchase stock, warrants, securities or other property
of the Company which is not made pro rata to the record holders of any class of shares of Common Stock. 
 (c) Fundamental
Transaction. If, at any time while this Warrant is outstanding, (i) the Company, directly or indirectly, in one or more related transactions effects any merger or consolidation of the Company with or into another Person, (ii) the
Company, directly or indirectly, effects any sale, lease, license, assignment, transfer, conveyance or other disposition of all or substantially all of its assets in one or a series of related transactions, (iii) any, direct or indirect,
purchase offer, tender offer or exchange offer (whether by the Company or another Person) is completed pursuant to which holders of Common Stock are permitted to sell, tender or exchange their shares for other securities, cash or property and has
been accepted by the holders of 50% or more of the outstanding Common Stock, (iv) the Company, directly or indirectly, in one or more related transactions effects any 







 
reclassification, reorganization or recapitalization of the Common Stock or any compulsory share exchange pursuant to which the Common Stock is effectively converted into or exchanged for other
securities, cash or property, or (v) the Company, directly or indirectly, in one or more related transactions consummates a stock or share purchase agreement or other business combination (including, without limitation, a reorganization,
recapitalization, spin-off or scheme of arrangement) with another Person or group of Persons whereby such other Person or group acquires more than 50% of the outstanding shares of Common Stock (not including any shares of Common Stock held by the
other Person or other Persons making or party to, or associated or affiliated with the other Persons making or party to, such stock or share purchase agreement or other business combination) (each a “Fundamental Transaction”), then,
upon any subsequent exercise of this Warrant, the Holder shall have the right to receive, for each Warrant Share that would have been issuable upon such exercise immediately prior to the occurrence of such Fundamental Transaction (without regard to
any limitation in Section 2(e) on the exercise of this Warrant), the number of shares of Common Stock of the Company, if it is the surviving corporation, and any additional consideration (including any shares in any successor corporation or
other entity acquiring the Company) (the “Alternate Consideration”) receivable as a result of such Fundamental Transaction by a holder of a share of Common Stock for which this Warrant is exercisable immediately prior to such
Fundamental Transaction (without regard to any limitation in Section 2(e) on the exercise of this Warrant). For purposes of any such exercise, the determination of the Exercise Price shall be appropriately adjusted to apply to such Alternate
Consideration based on the amount of Alternate Consideration issuable in respect of one share of Common Stock in such Fundamental Transaction, and the Company shall apportion the Exercise Price among the Alternate Consideration in a reasonable
manner reflecting the relative value of any different components of the Alternate Consideration. If holders of Common Stock are given any choice as to the securities, cash or property to be received in a Fundamental Transaction, then the Holder
shall be given the same choice as to the Alternate Consideration it receives upon any exercise of this Warrant following such Fundamental Transaction. Notwithstanding anything to the contrary, in the event of a Fundamental Transaction that is
(1) an all cash transaction, (2) a “Rule 13e-3 transaction” as defined in Rule 13e-3 under the Exchange Act, or (3) a Fundamental Transaction involving a person or entity not traded on a national securities exchange,
including, but not limited to, the NYSE MKT, the Nasdaq Global Select Market, the Nasdaq Global Market, or the Nasdaq Capital Market, the Company or any Successor Entity (as defined below) shall, at the option of the Holder or the Company or any
Successor Entity, exercisable at any time concurrently with, or within 30 days after, the consummation of the Fundamental Transaction, purchase this Warrant from the Holder by paying to the Holder an amount of cash equal to the Black Scholes Value
of the remaining unexercised portion of this Warrant on the date of the consummation of such Fundamental Transaction. “Black Scholes Value” means the value of this Warrant based on the Black-Scholes Option Pricing Model obtained
from the “OV” function on Bloomberg determined as of the day of consummation of the applicable Fundamental Transaction for pricing purposes and reflecting (A) a risk-free interest rate corresponding to the U.S. Treasury rate for a
period equal to the time between the date of the public announcement of the applicable Fundamental Transaction and the Termination Date, (B) an expected volatility equal to the greater of 100% and the 100 day volatility obtained from the HVT
function on Bloomberg as of the Trading Day immediately following the public announcement of the applicable Fundamental Transaction, (C) the underlying price per share used in such calculation shall be the sum of the price per share being
offered in cash, if any, plus the value of any non-cash consideration, if any, being offered in such Fundamental Transaction and (D) a remaining option time equal to the time between the date of the public announcement of the applicable
Fundamental Transaction and the Termination Date. The Company shall cause any successor entity in a Fundamental Transaction in which the Company is not the survivor (the “Successor Entity”) to assume in writing all of the
obligations of the Company under this Warrant in accordance with the provisions of this Section 3(c), and to deliver to the Holder in exchange for this Warrant a security of the Successor Entity evidenced by a written instrument substantially
similar in form and substance to this Warrant which is exercisable for a corresponding number of shares of capital stock of such Successor Entity (or its parent entity) equivalent to the shares of Common Stock acquirable and receivable upon exercise
of this Warrant (without regard to any limitations on the exercise of this Warrant) prior to such Fundamental Transaction, and with an exercise price which applies the exercise price hereunder to such shares of capital stock (but taking into account
the relative value of the shares of Common Stock pursuant to such Fundamental Transaction and the value of such shares of capital stock, such number of shares of capital stock and such exercise price being for the purpose of protecting the economic
value of this Warrant immediately prior to the consummation of such Fundamental Transaction). Upon the occurrence of any such Fundamental Transaction, the Successor Entity shall succeed to, and be substituted for (so that from and after the date of
such Fundamental Transaction, the provisions of this Warrant and the other Transaction Documents referring to the “Company” shall refer instead to the Successor Entity), and may exercise every right and power of the Company and shall
assume all of the obligations of the Company under this Warrant and the other Transaction Documents with the same effect as if such Successor Entity had been named as the Company herein. 







 (e) Calculations. All calculations under this Section 3 shall be made to the
nearest cent or the nearest 1/100th of a share, as the case may be. For purposes of this Section 3, the number of shares of Common Stock deemed to be issued and outstanding as of a given date shall be the sum of the number of shares of Common
Stock (excluding treasury shares, if any) issued and outstanding. 
 (f) Notice to Holder. 

(i) Adjustment to Exercise Price. Whenever the Exercise Price is adjusted pursuant to any provision of this Section 3, the
Company shall promptly give written notice thereof to the Holder setting forth the Exercise Price after such adjustment and any resulting adjustment to the number of Warrant Shares and setting forth a brief statement of the facts requiring such
adjustment. 
 (ii) Notice to Allow Exercise by Holder. If (A) the Company shall declare a dividend (or any other
distribution in whatever form) on the Common Stock, (B) the Company shall declare a special nonrecurring cash dividend on or a redemption of the Common Stock, (C) the Company shall authorize the granting to all holders of the Common Stock
rights or warrants to subscribe for or purchase any shares of capital stock of any class or of any rights, (D) the approval of any stockholders of the Company shall be required in connection with any reclassification of the Common Stock, any
consolidation or merger to which the Company is a party, any sale or transfer of all or substantially all of the assets of the Company, or any compulsory share exchange whereby the Common Stock is converted into other securities, cash or property,
or (E) the Company shall authorize the voluntary or involuntary dissolution, liquidation or winding up of the affairs of the Company, then, in each case, the Company shall cause to be mailed to the Holder at its last address as it shall appear
upon the Warrant Register of the Company, at least 10 business days prior to the applicable record or effective date hereinafter specified, a notice stating (x) the date on which a record is to be taken for the purpose of such dividend,
distribution, redemption, rights or warrants, or if a record is not to be taken, the date as of which the holders of the Common Stock of record to be entitled to such dividend, distributions, redemption, rights or warrants are to be determined or
(y) the date on which such reclassification, consolidation, merger, sale, transfer or share exchange is expected to become effective or close, and the date as of which it is expected that holders of the Common Stock of record shall be entitled
to exchange their shares of the Common Stock for securities, cash or other property deliverable upon such reclassification, consolidation, merger, sale, transfer or share exchange; provided that the failure to mail such notice or any defect therein
or in the mailing thereof shall not affect the validity of the corporate action required to be specified in such notice. To the extent that any notice provided hereunder constitutes, or contains, material, non-public information regarding the
Company, the Company shall simultaneously file such notice with the Commission pursuant to a Current Report on Form 8-K. The Holder shall remain entitled to exercise this Warrant during the period commencing on the date of such notice to the
effective date of the event triggering such notice except as may otherwise be expressly set forth herein. 
 Section 4. Transfer of
Warrant. 
 (a) Transferability. This Warrant and all rights hereunder are transferable, in whole or in part, upon surrender
of this Warrant at the principal office of the Company or its designated agent, together with a written assignment of this Warrant substantially in the form attached hereto duly executed by the Holder or its agent or attorney and funds sufficient to
pay any transfer taxes payable upon the making of such transfer. Upon such surrender and, if required, such payment, the Company shall execute and deliver a new Warrant or Warrants in the name of the assignee or assignees, as applicable, and in the
denomination or denominations specified in such instrument of assignment, and shall issue to the assignor a new Warrant evidencing the portion of this Warrant not so assigned, and this Warrant shall promptly be cancelled. The Warrant, if properly
assigned in accordance herewith, may be exercised by a new holder for the purchase of Warrant Shares without having a new Warrant issued. This Section 4(a) is subject in its entirety to Section 4(b) below. 

(b) Restrictions on Transferability. 

(i) Restrictions on Transferability. Neither this Warrant nor any of the Warrant Shares (collectively, the
“Securities”) shall be sold, assigned, transferred or pledged except upon the conditions specified in this Section 4(b). 







 (ii) Restrictive Legend. If any of the Securities (or any other securities issued in
respect of the Securities upon any stock split, stock dividend, recapitalization, merger, consolidation or similar event) have not been previously registered under the Securities Act, each certificate representing the Securities (or any other
securities issued in respect of the Securities upon any stock split, stock dividend, recapitalization, merger, consolidation or similar event), shall (unless, in the case of the outstanding Warrant Shares, the Warrant Shares may be sold pursuant to
Rule 144 without volume or manner of sale limitations) be stamped or otherwise imprinted with a legend in substantially the following form (in addition to any legend required under applicable state securities laws): 

THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES LAWS. NO SALE OR DISPOSITION
MAY BE EFFECTED WITHOUT (i) EFFECTIVE REGISTRATION STATEMENTS RELATED THERETO, (ii) AN OPINION OF COUNSEL OR OTHER EVIDENCE, REASONABLY SATISFACTORY TO THE COMPANY, THAT SUCH REGISTRATIONS ARE NOT REQUIRED, OR (iii) PURSUANT TO RULE
144 UNDER THE SECURITIES ACT. 
 (iii) Removal of Legends. The legend set forth above shall be removed and the Company shall issue a
certificate without such legend to the holder of the Securities upon which such legend is stamped or issue to such holder by electronic delivery at the applicable balance account at the DTC if, unless otherwise required by state securities laws,
(i) such Securities are registered for resale under the Securities Act, (ii) in connection with a sale, assignment or other transfer, such holder provides the Company with an opinion of counsel or other evidence reasonably satisfactory to
the Company to the effect that such sale, assignment or transfer of the Securities may be made without registration under the applicable requirements of the Securities Act, or (iii) the Securities can be sold, assigned or transferred pursuant
to Rule 144. If the Holder seeks an opinion as to transfer without registration from Holder’s counsel, the Company shall provide such information to Holder’s counsel as Holder’s counsel reasonably requests for the purpose of rendering
such an opinion. 
 (iv) Sale, Assignment or Transfer of Warrant Shares. If the Holder effects a sale, assignment or transfer of
Warrant Shares pursuant to Rule 144, the Company shall permit the transfer and shall promptly instruct its transfer agent to issue, without any restrictive legend, one or more certificates or credit shares to the applicable balance accounts at DTC
in such name and in such denominations as specified by such Holder to effect such sale, transfer or assignment. 
 (c) New
Warrants. This Warrant may be divided or combined with other Warrants upon presentation hereof at the aforesaid office of the Company, together with a written notice specifying the names (assuming compliance with Section 4(b)) and
denominations in which new Warrants are to be issued, signed by the Holder or its agent or attorney. Subject to compliance with Section 4(a), as to any transfer which may be involved in such division or combination, the Company shall execute
and deliver a new Warrant or Warrants in exchange for the Warrant or Warrants to be divided or combined in accordance with such notice, following Holder’s compliance with Section 4(b). All Warrants issued on transfers or exchanges shall be
dated the initial issuance date of this Warrant and shall be identical with this Warrant except as to the number of Warrant Shares issuable pursuant thereto. 

(d) Warrant Register. The Company shall register this Warrant, upon records to be maintained by the Company for that purpose (the
“Warrant Register”), in the name of the record Holder hereof from time to time. The Company may deem and treat the registered Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any
distribution to the Holder, and for all other purposes, absent actual notice to the contrary. 
 Section 5. Investment Representations.
With respect to the acquisition of the Securities, Holder hereby represents and warrants to the Company as follows: 
 (a)
Investment. Holder is acquiring the Securities for investment for its own account, not as a nominee or agent, and not with the view to, or for resale in connection with, any distribution thereof. 

(b) Accredited Investor. Holder is an “accredited investor” as such term is defined in Rule 501 of Regulation D promulgated
under the Securities Act. 
 Section 6. Piggyback Registration Rights. To the extent the Company does not maintain an effective
registration statement for the Warrant Shares and in the further event that the Company files a registration statement with the 







 
Securities and Exchange Commission covering the sale of its shares of Common Stock (other than a registration statement on Form S-4 or S-8, or on another form, or in another context, in which
such “piggyback” registration would be inappropriate), then, for a period commencing on the Initial Exercise Date and terminating on the Termination Date, the Company shall give written notice of such proposed filing to the holders of
Warrant Shares as soon as practicable but in no event less than fifteen (15) days before the anticipated filing date, which notice shall describe the amount and type of securities to be included in such offering, the intended method(s) of
distribution, and the name of the proposed managing underwriter or underwriters, if any, of the offering, and offer to the holders of Warrant Shares in such notice the opportunity to register the sale of such number of shares of Warrant Shares as
such holders may request in writing within ten (10) days following receipt of such notice (a “Piggyback Registration”). If requested by the Holder, the Company shall cause such Holder’s Warrant Shares to be included in
such registration and shall use its best efforts to cause the managing underwriter or underwriters of a proposed underwritten offering to permit the Warrant Shares requested to be included in a Piggyback Registration on the same terms and conditions
as any similar securities of the Company and to permit the sale or other disposition of such Warrant Shares in accordance with the intended method(s) of distribution thereof unless, in the reasonable judgment of the Company and the managing
underwriters, the inclusion of the Warrant Shares in the Registration Statement would materially impair the Company’s or the selling stockholder’s ability to sell all of the shares otherwise included in such registration statement. All
holders of Warrant Shares proposing to distribute their securities through a Piggyback Registration that involves an underwriter or underwriters shall enter into an underwriting agreement in customary form with the underwriter or underwriters
selected for such Piggyback Registration. Reference is made to the Registration Rights Agreement, dated the date hereof, among the Company, the Placement Agents and the Purchasers identified on the signature pages thereto, with respect to certain
other registration rights granted to the Holder. 
 Section 7. Miscellaneous. 

(a) No Rights as Stockholder Until Exercise. This Warrant does not entitle the Holder to any voting rights, dividend rights or
other rights as a stockholder of the Company prior to the exercise hereof as set forth in Section 2(d)(i), except as expressly set forth in Section 3. 

(b) Loss, Theft, Destruction or Mutilation of Warrant. The Company covenants that upon receipt by the Company of evidence
reasonably satisfactory to it of the loss, theft, destruction or mutilation of this Warrant or any stock certificate relating to the Warrant Shares, and in case of loss, theft or destruction, of indemnity or security reasonably satisfactory to it
(which, in the case of the Warrant, shall not include the posting of any bond), and upon surrender and cancellation of such Warrant or stock certificate, if mutilated, the Company will make and deliver a new Warrant or stock certificate of like
tenor and dated as of such cancellation, in lieu of such Warrant or stock certificate. 
 (c) Saturdays, Sundays, Holidays, etc.
If the last or appointed day for the taking of any action or the expiration of any right required or granted herein shall not be a business day, then, such action may be taken or such right may be exercised on the next succeeding business day. 

(d) Authorized Shares. 
 The Company
covenants that, during the period the Warrant is outstanding, it will reserve from its authorized and unissued Common Stock a sufficient number of shares to provide for the issuance of the Warrant Shares upon the exercise of any purchase rights
under this Warrant. The Company further covenants that its issuance of this Warrant shall constitute full authority to its officers who are charged with the duty of executing stock certificates to execute and issue the necessary Warrant Shares upon
the exercise of the purchase rights under this Warrant. The Company will take all such commercially reasonable action as may be necessary to assure that such Warrant Shares may be issued as provided herein without violation of any applicable law or
regulation, or of any requirements of the trading market upon which the Common Stock may be listed. The Company covenants that all Warrant Shares which may be issued upon the exercise of the purchase rights represented by this Warrant will, upon
exercise of the purchase rights represented by this Warrant and payment for such Warrant Shares in accordance herewith, be duly authorized, validly issued, fully paid and nonassessable and free from all taxes, liens and charges created by the
Company in respect of the issue thereof (other than taxes in respect of any transfer occurring contemporaneously with such issue). 
 Except and to the
extent as waived or consented to by the Holder, the Company shall not by any action, including, without limitation, amending its certificate of incorporation or through any reorganization, transfer of assets,








 
consolidation, merger, dissolution, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will
at all times in good faith assist in the carrying out of all such terms and in the taking of all such actions as may be necessary or appropriate to protect the rights of Holder as set forth in this Warrant against impairment. Without limiting the
generality of the foregoing, the Company will (i) not increase the par value of any Warrant Shares above the amount payable therefor upon such exercise immediately prior to such increase in par value, (ii) take all such action as may be
necessary or appropriate in order that the Company may validly and legally issue fully paid and nonassessable Warrant Shares upon the exercise of this Warrant and (iii) use commercially reasonable efforts to obtain all such authorizations,
exemptions or consents from any public regulatory body having jurisdiction thereof, as may be, necessary to enable the Company to perform its obligations under this Warrant. 

Before taking any action which would result in an adjustment in the number of Warrant Shares for which this Warrant is exercisable or in the Exercise Price,
the Company shall obtain all such authorizations or exemptions thereof, or consents thereto, as may be necessary from any public regulatory body or bodies having jurisdiction thereof. 

(e) Jurisdiction. All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall be
determined in accordance with the laws of the State of New York, without regard to conflict of laws principles, and federal or state courts sitting in the State of New York shall have exclusive jurisdiction over matters arising out of this Warrant.

 (f) Restrictions. The Holder acknowledges that the Warrant Shares acquired upon the exercise of this Warrant, if not
registered, and the Holder does not utilize cashless exercise, will have restrictions upon resale imposed by state and federal securities laws. 

(g) Nonwaiver and Expenses. No course of dealing or any delay or failure to exercise any right hereunder on the part of Holder or
the Company shall operate as a waiver of such right or otherwise prejudice that party’s rights, powers or remedies. Without limiting any other provision of this Warrant or the Agreements, if either party willfully and knowingly fails to comply
with any provision of this Warrant, which results in any material damages to the other party, the first party shall pay such amounts as shall be sufficient to cover any costs and expenses including, but not limited to, reasonable attorneys’
fees, including those of appellate proceedings, incurred by the affected party in collecting any amounts due pursuant hereto or in otherwise enforcing any of its rights, powers or remedies hereunder. 

(h) Notices. Any notice, request or other document required or permitted to be given or delivered to the Holder by the Company
shall be delivered in accordance with the notice provisions of the Agreements. 
 (i) Limitation of Liability. No provision
hereof, in the absence of any affirmative action by the Holder to exercise this Warrant to purchase Warrant Shares, and no enumeration herein of the rights or privileges of the Holder, shall give rise to any liability of the Holder for the purchase
price of any Common Stock or as a stockholder of the Company, whether such liability is asserted by the Company or by creditors of the Company. 

(j) Remedies. The Holder, in addition to being entitled to exercise all rights granted by law, including recovery of damages, will
be entitled to specific performance of its rights under this Warrant. The Company agrees that monetary damages would not be adequate compensation for any loss incurred by reason of a breach by it of the provisions of this Warrant and hereby agrees
to waive and not to assert the defense in any action for specific performance that a remedy at law would be adequate. 

(k) Successors and Assigns. Subject to applicable securities laws, this Warrant and the rights and obligations evidenced hereby
shall inure to the benefit of and be binding upon the successors and permitted assigns of the Company and the successors and permitted assigns of Holder. The provisions of this Warrant are intended to be for the benefit of any Holder from time to
time of this Warrant and shall be enforceable by the Holder or holder of Warrant Shares. 
 (l) Amendment. This Warrant may be
modified or amended or the provisions hereof waived with the written consent of the Company and the Holder. 
 (m) Severability.
Wherever possible, each provision of this Warrant shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Warrant shall be prohibited by or invalid under applicable law, such provision
shall be ineffective to the extent of such prohibition or invalidity, without invalidating the remainder of such provision or the remaining provisions of this Warrant. 







 (n) Headings. The headings used in this Warrant are for the convenience of reference
only and shall not, for any purpose, be deemed a part of this Warrant. 
 ******************** 

(Signature Page Follows) 







 IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its officer thereunto duly authorized
as of the date first above indicated. 
  

			
	CONTRAFECT CORPORATION
		
	By:		  

			Name:
			Title:


 [Signature Page to Placement Agent’s Warrant] 







 NOTICE OF EXERCISE 

TO: CONTRAFECT CORPORATION 
 (1) The undersigned hereby
elects to purchase                  Warrant Shares of the Company pursuant to the terms of the attached Warrant, dated June     , 2015, and tenders
herewith payment of the exercise price in full, together with all applicable transfer taxes, if any. 
 (2) Payment shall take the form of (check applicable
box): 
  ̈ lawful money of the United States by wire transfer or cashier’s check drawn on a United
States bank; or 
  ̈ if permitted by the terms of the Warrant, the cancellation of such number of Warrant
Shares as is necessary, in accordance with the formula set forth in Section 2(c), to exercise this Warrant with respect to the maximum number of Warrant Shares purchasable pursuant to the cashless exercise procedure set forth in
Section 2(c). 
 (3) Please issue said Warrant Shares in the name of the undersigned or in such other name as is specified below: 

 
  

The Warrant Shares shall be delivered to the following DWAC Account Number: 
  

 
  

 
  

 
 Holder hereby makes as of the date hereof the
representations set forth in Section 5 of the Warrant. 
 [SIGNATURE OF HOLDER] 

 

			
	Name of Investing Entity:		  



			
		
	Signature of Authorized Signatory of Investing Entity:		  



			
		
	Name of Authorized Signatory:		  



			
		
	Title of Authorized Signatory:		  



			
		
	Date:		  









 ASSIGNMENT FORM 

(To assign the foregoing warrant, execute 

this form and supply required information. 

Do not use this form to exercise the warrant.) 

FOR VALUE RECEIVED, [            ] all of or
[                ] shares of the foregoing Warrant and all rights evidenced thereby are hereby assigned to 

 

			
	  
		whose address is


			
		
	  
		.
		
	  
		

 Date:
            ,         
  

			
	Holder’s Signature:		  

		
	Holder’s Address:		  

		
			  



  

			
	Signature Guaranteed:		  


 NOTE: The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without
alteration or enlargement or any change whatsoever, and must be guaranteed by a bank or trust company. Officers of corporations and those acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the
foregoing Warrant.