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 18, 2015

ORGANOVO HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Commission File Number: 001-35996

6275 Nancy Ridge Dr.,

San Diego, California 92121

(Address of principal executive offices, including zip code)

(858) 550-9994

(Registrant’s telephone number, including area code)

(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):

On June 18, 2015, Organovo Holdings, Inc., a Delaware corporation (the “Company”), entered into an Underwriting Agreement (the “Underwriting Agreement”) with Jefferies LLC and Piper Jaffray & Co., acting as representatives of the underwriters named in the Underwriting Agreement (the “Underwriters”) and as joint book-running managers, relating to the issuance and sale of 9,425,000 shares of the Company’s common stock, par value $0.001 per share (the “Offering”). The price to the public in the Offering is $4.25 per share, and the Underwriters have agreed to purchase the shares from the Company pursuant to the Underwriting Agreement at a price of $3.995 per share. Under the terms of the Underwriting Agreement, the Company has granted the Underwriters an option, exercisable for 30 days, to purchase up to an additional 1,413,750 shares. The net proceeds to the Company from the Offering are expected to be approximately $37.3 million, after deducting underwriting discounts and commissions and estimated Offering expenses payable by the Company, assuming no exercise by the Underwriters of its option to purchase additional shares of common stock. The transactions contemplated by the Underwriting Agreement are expected to close on June 23, 2015, subject to the satisfaction of customary closing conditions.

The Offering was made pursuant to the Company’s shelf registration statement on Form S-3, initially filed with the Securities and Exchange Commission (“SEC”) on February 27, 2015, which became effective on March 17, 2015 (File No. 333-202382) and the related prospectus supplement filed with the SEC pursuant to Rule 424(b) under the Securities Act.

The Underwriting Agreement contains customary representations, warranties and agreements by the Company, customary conditions to closing, indemnification obligations of the Company and the Underwriter, including for liabilities under the Securities Act, other obligations of the parties and termination provisions. A copy of the Underwriting Agreement is filed as Exhibit 1.1 to this Current Report and is incorporated herein by reference. The foregoing description of the terms of the Underwriting Agreement is qualified in its entirety by the Underwriting Agreement.

The Underwriting Agreement is attached hereto as an exhibit to provide interested persons with information regarding its terms, but 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 as of specific dates indicated therein, were solely for the benefit of the parties to the Underwriting Agreement, and may be subject to limitations agreed upon by the parties, including being qualified by confidential disclosures exchanged between the parties in connection with the execution of the Underwriting Agreement.

The legal opinion, including the related consent, of DLA Piper LLP (US) relating to the legality of the issuance and sale of the shares of the Company’s common stock in the Offering is filed as Exhibit 5.1 to this Current Report.

This Current Report contains forward-looking statements that involve risk and uncertainties, such as statements related to the anticipated closing of the Offering and the amount of net proceeds expected from the Offering. The risks and uncertainties involved include the Company’s ability to satisfy certain conditions to closing on a timely basis or at all, as well as other risks detailed from time to time in the Company’s SEC filings.

Press Releases Regarding the Offering

On June 18, 2015, the Company issued a press release announcing that it had priced the Offering. A copy of the press release is attached hereto as Exhibit 99.1 and are incorporated herein by reference.

(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