UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 20, 2016

ContraFect Corporation

(Exact name of registrant as specified in its charter)

28 Wells Avenue, 3rd Floor, Yonkers, New York 10701

(Address of principal executive offices) (Zip Code)

(914) 207-2300

Registrant’s telephone number, including area code

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 1.01 Entry into a Material Definitive Agreement

On January 20, 2016, ContraFect Corporation (the “Company”) entered into a Sales Agreement (the “Sales Agreement”) with Cowen and Company, LLC (“Cowen”) to sell shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), with aggregate gross sales proceeds of up to $30,000,000, from time to time, through an “at the market” equity offering program under which Cowen will act as sales agent.

Under the Sales Agreement, the Company will set the parameters for the sale of shares, including the number of shares to be issued, the time period during which sales are requested to be made, limitations on the number of shares that may be sold in any one trading day and any minimum price below which sales may not be made. Subject to the terms and conditions of the Sales Agreement, Cowen may sell the shares by methods deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended (the “Securities Act”), including sales made through The Nasdaq Capital Market, on any other existing trading market for the Common Stock or to or through a market maker. In addition, if expressly authorized by the Company, Cowen may also sell shares in privately negotiated transactions. The Company will pay Cowen a commission equal to three percent (3.0%) of the gross sales proceeds of any Common Stock sold through Cowen under the Agreement, and also has provided Cowen with customary indemnification rights. The Sales Agreement may be terminated by the Company upon prior notice to Cowen or by Cowen upon prior notice to the Company, or at any time under certain circumstances, including but not limited to the occurrence of a material adverse change in the Company.

The foregoing description of the material terms of the Sales Agreement is qualified in its entirety by reference to the full agreement, a copy of which is filed as Exhibit 1.1 to this Current Report on Form 8-K and is incorporated herein by reference.

This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of any offer to buy the securities discussed herein, nor shall there be any offer, solicitation or sale of the securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Exhibit Index