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, 2015

ELEVEN BIOTHERAPEUTICS, INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (617) 871-9911

None

(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:

On January 20, 2015, the Board of Directors (the “Board”) of Eleven Biotherapeutics, Inc., a Delaware corporation (the “Company”), following the recommendation of the Nominating and Corporate Governance Committee of the Board, elected Mr. Barry Gertz and Dr. Jay Duker to fill vacancies on the Board. The elections were effective as of January 20, 2015. Mr. Gertz was designated as a Class I member of the Board to serve until the 2015 annual meeting of the stockholders of the Company and thereafter until his successor has been duly elected and qualified, or until his earlier death, resignation or removal. Dr. Duker was designated as a Class II member of the Board to serve until the 2016 annual meeting of the stockholders of the Company and thereafter until his successor has been duly elected and qualified, or until his earlier death, resignation or removal.

There are no arrangements or understandings between Mr. Gertz and any other person pursuant to which he was elected as a director. There are no arrangements or understandings between Dr. Duker and any other person pursuant to which he was elected as a director. There are no transactions in which Mr. Gertz or Dr. Duker has an interest requiring disclosure under Item 404(a) of Regulation S-K of the Securities Act of 1933, as amended (the “Securities Act”). Mr. Gertz and Dr. Duker will be compensated in the same manner as the Company’s other non-employee directors. Information concerning the current compensation of the Company’s directors is set forth in the Company’s annual report on Form 10-K filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 31, 2014. Accordingly, Mr. Gertz and Dr. Duker each received, upon their election to the Board, an option to purchase 16,143 shares of common stock of the Company at an exercise price of $11.85 per share.

In connection with their elections, Mr. Gertz and Dr. Duker will each enter into the Company’s standard form of Indemnification Agreement, a copy of which was filed as Exhibit 10.12 to Amendment No. 1 to the Company’s Registration Statement on Form S-1 (File No. 333-193131) filed with the SEC on January 23, 2014. Pursuant to the terms of this agreement, the Company may be required, among other things, to indemnify each of Mr. Gertz and Dr. Duker for some expenses, including attorneys’ fees, judgments, fines and settlement amounts incurred by each of them in any action or proceeding arising out of each of their service as of the Company’s directors.

SIGNATURE

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.