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 13, 2015

AVALANCHE BIOTECHNOLOGIES, INC.

(Exact name of registrant as specified in its charter)

1035 O’Brien Drive, Suite A

Menlo Park, CA 94025

(650) 272-6269

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including area code: (650) 272-6269

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 13, 2015, Avalanche Biotechnologies, Inc., a Delaware corporation (the “Company”), completed its previously announced public offering of 2,399,457 shares of its common stock at a price to the public of $59.00 per share (the “Offering”). In addition, the underwriters for the Offering exercised in full their option to purchase 359,918 additional shares of the Company’s common stock (the “Underwriters’ Option”), which purchase was also completed on January 13, 2015. The Company estimates its net proceeds from the Offering, including from the exercise of the Underwriters’ Option, to be approximately $130.5 million, after deducting underwriting discounts and commissions and estimated offering expenses.

A Prospectus relating to the Offering was filed on January 7, 2015 with the Securities and Exchange Commission pursuant to Rule 424(b) of the Securities Act of 1933, as amended (the “Securities Act”).

The information furnished pursuant to this Item 7.01 of this Current Report on Form 8-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act or under the Exchange Act, regardless of any general incorporation language in any such filing, unless the Company expressly sets forth in such filing that such information is to be considered “filed” or incorporated by reference therein.

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.