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): June 30, 2017

CLEARSIDE BIOMEDICAL, INC.

(Exact Name of Registrant as Specified in its Charter)

900 North Point Parkway, Suite 200

Alpharetta, Georgia 30005

(Address of Principal Executive Office) (Zip Code)

Registrant’s telephone number, including area code: (678) 270-3631

Not Applicable

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 (see General Instruction A.2 below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company  ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☒

On June 30, 2017, Clearside Biomedical, Inc. (the “Company”) entered into a Sales Agreement (the “Agreement”) with Cowen and Company, LLC (“Cowen”) under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, par value $0.001 per share (the “Common Stock”), having an aggregate offering price of up to $50,000,000 through Cowen as its sales agent. The issuance and sale, if any, of Common Stock by the Company under the Agreement is subject to the effectiveness of the Company’s registration statement on Form S-3, to be filed with the Securities and Exchange Commission on July 3, 2017. The Company makes no assurances as to if or whether the registration statement will become effective or, if it does become effective, as to the continued effectiveness of the registration statement.

Cowen may sell the Common Stock by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415 of the Securities Act of 1933, as amended. Cowen will use commercially reasonable efforts to sell the Common Stock from time to time, based upon instructions from the Company (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company will pay Cowen a commission equal to up 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 Company is not obligated to make any sales of Common Stock under the Agreement. The offering of shares of Common Stock pursuant to the Agreement will terminate upon the earlier of (i) the sale of all Common Stock subject to the Agreement or (ii) termination of the Agreement in accordance with its terms.

The foregoing description of the Agreement is not complete and is qualified in its entirety by reference to the full text of the Agreement, a copy of which is filed herewith as Exhibit 10.1 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 an 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, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EXHIBIT INDEX