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): April 29, 2015

KYTHERA BIOPHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

30930 Russell Ranch Road, Third Floor

Westlake Village, CA 91362

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including area code: (818) 587-4500

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:

o            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01      Other Events.

On April 29, 2015, KYTHERA Biopharmaceuticals, Inc. (the “Company”) issued a press release announcing that the U.S. Food and Drug Administration (the “FDA”) had approved KYBELLA™ (also known as ATX-101) for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat in adults.

The Company’s press release relating to the FDA’s approval of KYBELLA™ is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01      Financial Statements and Exhibits.

The following Exhibit is filed as part of this Current Report on Form 8-K.

(d)   Exhibits.

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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.

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