424(b)(3)

Filed Pursuant to Rule 424(b)(3) and Rule 424(c)

Registration No. 333-156556

June 11, 2009

PROSPECTUS SUPPLEMENT NO. 11

5,929,212 SHARES OF COMMON STOCK

ANTIGENICS INC.

This prospectus supplement amends the prospectus dated March 18, 2009 (as supplemented on April 15, 2009, April 17, 2009, April 22, 2009, April 27, 2009, May 4, 2009, May 11, 2009, May 27, 2009, June 4, 2009, June 8, 2009 and June 9, 2009) that relates to the issuance of up to 5,929,212 shares of our common stock, par value $0.01 per share (“common stock”), issuable upon the conversion of 5,250 shares of Series B2 Convertible Preferred Stock, par value $0.01 per share (“Series B2 Convertible Preferred Stock”). If the shares of Series B2 Convertible Preferred Stock are converted through payment of cash consideration, if at all, we will receive the cash from such conversion.

This prospectus supplement is being filed to include the information set forth in the Current Report on Form 8-K filed on June 11, 2009, which is set forth below. This prospectus supplement should be read in conjunction with the prospectus dated March 18, 2009, Prospectus Supplement No. 1 dated April 15, 2009, Prospectus Supplement No. 2 dated April 17, 2009, Prospectus Supplement No. 3 dated April 22, 2009, Prospectus Supplement No. 4 dated April 27, 2009, Prospectus Supplement No. 5 dated May 4, 2009, Prospectus Supplement No. 6 dated May 11, 2009, Prospectus Supplement No. 7 dated May 27, 2009, Prospectus Supplement No. 8 dated June 4, 2009, Prospectus Supplement No. 9 dated June 8, 2009, and Prospectus Supplement No. 10 dated June 9, 2009, which are to be delivered with this prospectus supplement.

Our common stock is quoted on The NASDAQ Capital Market (“NASDAQ”) under the ticker symbol “AGEN.” On June 9, 2009, the last reported closing price per share of our common stock was $2.07 per share.

Investing in our securities involves a high degree of risk. Before investing in any of our securities, you should read the discussion of material risks in investing in our common stock. See “Risk Factors” on page 1 of the prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

THE DATE OF THIS PROSPECTUS SUPPLEMENT NO. 11 IS JUNE 11, 2009


 

 

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

June 5, 2009

Date of Report (Date of earliest event reported)

 

 

ANTIGENICS INC.

(Exact name of registrant as specified in its charter)

 

 

 

DELAWARE   000-29089   06-1562417

(State or other jurisdiction

of incorporation)

  (Commission File Number)  

(IRS Employer

Identification No.)

 

3 Forbes Road

Lexington, MA

  02421
(Address of principal executive offices)   (Zip Code)

781-674-4400

(Registrant’s telephone number, including area code)

 

 

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):

 

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

 

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

 

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

 

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

 

 

 


Item 1.01 Entry into a Material Definitive Agreement.

On June 5, 2009, Antigenics Inc. entered into Amendment Number Two to the License Agreement between the University of Connecticut Health Center (“UConn”) and Antigenics Inc. effective May 25, 2001, as amended, modifying the annual maintenance fees payable to UConn.


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.

 

    ANTIGENICS INC.

Date: June 11, 2009

  By:  

/s/ Shalini Sharp

    Shalini Sharp
    Chief Financial Officer