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): February 22, 2013

ANTHERA PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (510) 856-5600

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 February 22, 2013, the underwriters of our previously announced public offering of common stock that priced on January 25, 2013 exercised their option to purchase an additional 9,090,909 shares of common stock. With the sale of the additional shares, we will have sold a total of 69,696,970 shares of common stock in the public offering at a price to the public of $0.66 per share, resulting in expected aggregate gross proceeds to us of $46.0 million, before deducting customary underwriting discounts and commissions and expenses payable by us. The sale of the additional shares is expected to close on or about February 27, 2013, subject to customary closing conditions.  We intend to use the net proceeds from this offering for general corporate purposes.

2

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.

3