Form 424(b)(3)

Filed Pursuant to Rule 424(b)(3) and Rule 424(c)
Registration No. 333-156556

April 26, 2010

PROSPECTUS SUPPLEMENT NO. 24

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, June 9, 2009, June 11, 2009, June 15, 2009, July 7, 2009, July 15, 2009, August 3, 2009, August 5, 2009, September 11, 2009, September 18, 2009, November 12, 2009, January 5, 2010, March 1, 2010, and March 25, 2010) 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 April 22, 2010, 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, Prospectus Supplement No. 10 dated June 9, 2009, Prospectus Supplement No. 11 dated June 11, 2009, Prospectus Supplement No. 12 dated June 15, 2009, Prospectus Supplement No. 13 dated July 7, 2009, Prospectus Supplement No. 14 dated July 15, 2009, Prospectus Supplement No. 15 dated August 3, 2009, Prospectus Supplement No. 16 dated August 5, 2009, Prospectus Supplement No. 17 dated September 11, 2009, Prospectus Supplement No. 18 dated September 18, 2009, Prospectus Supplement No. 19 dated November 12, 2009, Prospectus Supplement No. 20 dated January 5, 2010, Prospectus Supplement No. 21 dated March 1, 2010, and Prospectus Supplement No. 23 dated March 25, 2010, 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 April 22, 2010, the last reported closing price per share of our common stock was $1.23 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. 24 IS APRIL 26, 2010

 

 

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

April 21, 2010

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 April 22, 2010, Antigenics Inc. (the “Company”) entered into a Securities Exchange Agreement (the “Agreement”) with Invus Public Equities LP, holders of an aggregate principal amount of $2,290,000 of the Company’s 5.25% convertible senior notes due February 2025 (the “Bonds”), to issue 954,167 shares of the Company’s common stock, par value $0.01 (the “Shares”) in exchange for cancellation of the Bonds, including accrued and unpaid interest.

On April 21, 2010, the Company entered into an agreement (the “Fourth Amendment of Rights Agreement”) with Ingalls & Synder Value Partners L.P., the majority holder of the Company’s Senior Secured Convertible Notes issued on October 30, 2006 (the “2006 Notes”). The Fourth Amendment of Rights Agreement amended the definition of an Event of Default under the 2006 Notes to exclude the redemption and repurchase of up to an additional $2,290,000 in aggregate principal amount of 2005 Notes, along with accrued but unpaid interest, in exchange for 954,167 shares of Common Stock of the Company, from certain holders thereof (the “Fourth 2005 Notes Redemption”) and modified certain anti-dilutive rights of the holders of the 2006 Notes upon the Company’s issuance and sale of certain new securities up to the aggregate dollar amount expended by the Company for the Fourth 2005 Note Repurchase.

 

Item 3.02. Unregistered Sales of Equity Securities.

As described in Item 1.01 above, the Company will issue the Shares to Invus Public Equities LP in exchange for the Bonds. The Shares will not be registered under the Securities Act of 1933 (the “Act”). The Company will issue the Shares in a transaction exempt from the registration requirements of the Act by virtue of the exemption provided for in Section 3(a)(9) of the Act for securities exchanged by the issuer with an existing security holder. No commission or other remuneration was paid or given directly or indirectly for soliciting such exchange. Please see the discussion under Item 1.01 of this Current Report on Form 8-K for additional information regarding the transaction.

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: April 22, 2010   By:  

/S/    SHALINI SHARP        

    Shalini Sharp
    Chief Financial Officer