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): September 27, 2012

ONYX PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of incorporation)

249 East Grand Avenue
South San Francisco, California 94080
(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (650) 266-0000

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):

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 September 27, 2012, Onyx Pharmaceuticals, Inc. and Bayer Healthcare issued a press release reporting that the Food and Drug Administration, or FDA, had approved Bayer’s Stivarga® (regorafenib) tablets for treatment of patients with metastatic colorectal cancer. The press release dated September 27, 2012, titled “Bayer’s Stivarga® (regorafenib) Tablets Approved by the U.S. Food and Drug Administration for the Treatment of Metastatic Colorectal Cancer” is attached hereto as Exhibit 99.1 and is incorporated by reference herein.

ITEM 9.01       FINANCIAL STATEMENTS AND EXHIBITS

(d)  Exhibits

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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.

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EXHIBIT INDEX

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