As filed with the Securities and Exchange Commission on February 1, 2005

Registration No. 333-            



SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


FORM S-3
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933


ARENA PHARMACEUTICALS, INC.
(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of incorporation or organization)
  23-2908305
(I.R.S. Employer Identification No.)

6166 Nancy Ridge Drive
San Diego, California 92121
(858) 453-7200
(Address, including zip code, and telephone number,
including area code, of registrant's principal executive offices)


Steven W. Spector
Senior Vice President, General Counsel and Secretary
6166 Nancy Ridge Drive
San Diego, California 92121
(858) 453-7200
(Name, address, including zip code, and telephone number, including area code, of agent for service)


Copies to:
Steven M. Przesmicki
Cooley Godward LLP
4401 Eastgate Mall
San Diego, California 92121
(858) 550-6000


Approximate date of commencement of proposed sale to the public:
As soon as practicable after the effective date of this Registration Statement.


        If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. o

        If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ý

        If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ý 333-115670

        If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

        If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box. o

Calculation of Registration Fee


Title of Class of Securities to be Registered   Proposed Maximum
Aggregate Offering Price
  Amount of
Registration Fee (1)

Common Stock, par value $.0001 per share, including related rights to purchase Series A Junior Participating Preferred Stock   $1,750,000   $205.98

(1)
Calculated pursuant to rule 457(o) under the Securities Act.




EXPLANATORY NOTE

        This registration statement is being filed to register an additional $1,750,000 of shares of our common stock, par value $.0001, pursuant to Rule 462(b) of the Securities Act of 1933, as amended. In accordance with Rule 462(b), this registration statement incorporates by reference the contents of our registration statement on Form S-3 (File No. 333-115670) which was declared effective on June 23, 2004, including all amendments, supplements and exhibits thereto and all information incorporated by reference therein.

        The required opinions and consents are listed on the Exhibit Index attached to and filed with this registration statement.


SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Diego, State of California, on February 1, 2005.

    ARENA PHARMACEUTICALS, INC.

 

 

By:

/s/  
STEVEN W. SPECTOR      

 
      Steven W. Spector, Senior Vice President, General Counsel and Secretary
         

        Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

Signature
  Date

By:

*

Jack Lief, Chief Executive Officer and Director
(principal executive officer)

 

February 1, 2005

By:

*

Robert E. Hoffman, CPA, Vice President, Finance and Chief Accounting Officer (principal financial and accounting officer)

 

February 1, 2005

By:

*

Donald D. Belcher, Director

 

February 1, 2005

By:

*

Scott H. Bice, Director

 

February 1, 2005

By:

*

Duke K. Bristow, Ph.D., Director

 

February 1, 2005

By:


Harry F. Hixson, Jr., Ph.D., Director

 

 

By:

*

J. Clayburn La Force Jr., Ph.D., Director

 

February 1, 2005

By:


Louis J. Lavigne, Jr., Director

 

 

By:


Tina S. Nova, Ph.D., Director

 

 

By:

*

Robert L. Toms, Sr., Director

 

February 1, 2005

 

 

 

 

 

 

 

 

* By:

/s/  
STEVEN W. SPECTOR      
Steven W. Spector
Attorney-in-fact

 

 

 

 

 

 

 

 

 

 

INDEX TO EXHIBITS

Exhibit Number
  Description of Document

5.1   Opinion of Cooley Godward LLP

23.1

 

Consent of Cooley Godward LLP (included as Exhibit 5.1 to this filing)

23.2

 

Consent of Ernst & Young LLP, Independent Auditors

24.1

 

Power of Attorney (1)

(1)
Previously filed on the signature page to Registrant's registration statement on Form S-3 (No. 333-115670), filed with the SEC on May 20, 2004.