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): February 27, 2014

AMPIO PHARMACEUTICALS, INC.

(Exact name of registrant as specified in Charter)

5445 DTC Parkway, Suite 925

Greenwood Village, Colorado 80111

(Address of principal executive offices, including zip code)

(720) 437-6500

(Registrant’s telephone number, including area code)

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 (see General Instruction A.2. below):

Item 1.01 Entry into a Material Definitive Agreement.

On February 27, 2014, Ampio Pharmaceuticals, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Citigroup Global Markets Inc. and Jefferies LLC as the underwriters (the “Underwriters”), related to the registered offering (the “Offering”) of 8,500,000 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”). The offering price to the public was $7.00 per share. Under the terms of the Underwriting Agreement, the Company granted the Underwriters an option, exercisable for 30 days, to purchase 1,275,000 additional shares of Common Stock at the same price per share as the Shares.

The Offering is expected to close on March 5, 2014, subject to the satisfaction of customary closing conditions. The net proceeds to the Company are expected to be approximately $55.0 million, after deducting underwriting discounts and commissions and estimated expenses payable by the Company associated with the Offering. The Offering is being made pursuant to the Company’s existing shelf registration statements on Form S-3 (File Nos. 333-177116 and 333-193096), which were filed with the Securities and Exchange Commission (the “Commission”) on September 30, 2011 and December 26, 2013, respectively, and declared effective by the Commission on October 28, 2011 and January 22, 2014, respectively, and are described in more detail in a prospectus supplement filed February 24, 2014 and accompanying base prospectuses dated October 28, 2011 and January 22, 2014, respectively.

The Underwriting Agreement contains customary representations, warranties, and agreements by the Company, and customary conditions to closing, indemnification obligations of the Company and the Underwriters, including for liabilities under the Securities Act of 1933, as amended, other obligations of the parties, and termination provisions.

Pursuant to the Underwriting Agreement, the Company and its directors and executive officers agreed, subject to certain exceptions, not to offer, issue or sell any shares of Common Stock or securities convertible into or exercisable or exchangeable for shares of Common Stock for a period of ninety (90) days following the Offering without the prior written consent of the Underwriters.

The Underwriting Agreement has been attached hereto as an exhibit to provide investors and security holders with information regarding its terms. It is not intended to provide any other factual information about the Company. The representations, warranties and covenants contained in the Underwriting Agreement were made only for purposes of the Underwriting Agreement and as of specific dates, were solely for the benefit of the parties to the Underwriting Agreement, and may be subject to limitations agreed upon by the contracting parties, including being qualified by confidential disclosures exchanged between the parties in connection with the execution of the Underwriting Agreement.

A copy of the opinion of Goodwin Procter LLP relating to the legality of the issuance and sale of the securities in the Offering is attached as Exhibit 5.1 hereto. A copy of the Underwriting Agreement is filed herewith as Exhibit 1.1 and is incorporated herein by reference. The foregoing description of the Offering by the Company and the documentation related thereto does not purport to be complete and is qualified in its entirety by reference to such Exhibits.

Item 8.01 Other Events.

On February 24, 2014, the Company issued a press release announcing the launch of the Offering and on February 27, 2014, the Company issued a press release announcing the pricing of the Offering. Copies of the press releases are attached hereto as Exhibits 99.1 and 99.2, respectively, and are incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

SIGNATURE

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

Dated: February 28, 2014

EXHIBIT INDEX