UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13G/A

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 3)*

                           ARENA PHARMACEUTICALS, INC.
                                (Name of Issuer)

                         Common Stock, $0.0001 par value
                         (Title of Class of Securities)

                                    040047102
                                 (CUSIP Number)

                                October 31, 2005
                      (Date of Event which Requires Filing
                               of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

                                [X] Rule 13d-1(b)
                                [ ] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)


*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                          Continued on following pages
                                Page 1 of 9 Pages







CUSIP No. 040047102                                            Page 2 of 9 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  PERRY CORP.

2        Check the Appropriate Box If a Member of a Group (See Instructions)
                                            a.       [    ]
                                            b.       [    ]

3        SEC Use Only

4        Citizenship or Place of Organization

                    NEW YORK

                        5             Sole Voting Power
   Number of                                935,745
   Shares
 Beneficially           6             Shared Voting Power
  Owned By                                  0
    Each
  Reporting             7             Sole Dispositive Power
    Person                                  935,745
    With
                        8             Shared Dispositive Power
                                            0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                        935,745

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                        [   ]

11       Percent of Class Represented By Amount in Row (9)

                        2.6%

12       Type of Reporting Person (See Instructions)

                        IA, CO




CUSIP No. 040047102                                            Page 3 of 9 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  RICHARD C. PERRY

2        Check the Appropriate Box If a Member of a Group (See Instructions)
                                            a.       [    ]
                                            b.       [    ]

3        SEC Use Only

4        Citizenship or Place of Organization

                    NEW YORK

                        5             Sole Voting Power
   Number of                                935,745
   Shares
 Beneficially           6             Shared Voting Power
  Owned By                                  0
    Each
  Reporting             7             Sole Dispositive Power
    Person                                  935,745
    With
                        8             Shared Dispositive Power
                                            0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                        935,745

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                        [   ]

11       Percent of Class Represented By Amount in Row (9)

                        2.6%

12       Type of Reporting Person (See Instructions)

                        IN, HC





CUSIP No. 040047102                                            Page 4 of 9 Pages


Item 1(a)         Name of Issuer:

                  Arena Pharmaceuticals, Inc. (the "Issuer").

Item 1(b)         Address of the Issuer's Principal Executive Offices:

                  6166 Nancy Ridge Drive, San Diego, California 92121.

Item 2(a)         Name of Person Filing:

                  This statement is filed on behalf of each of the following
                  persons (collectively, the "Reporting Persons"):

                  i) Perry Corp.; and

                  ii) Richard C. Perry, in his capacities as the President and
                      sole stockholder of Perry Corp. ("Mr. Perry").

                  This statement  relates to Shares (as defined herein) held for
the accounts of two or more private  investment funds for which Perry Corp. acts
as general  partner,  and/or  managing  member of the  general  partner,  and/or
investment adviser.

Item 2(b)         Address of Principal Business Office or, if None, Residence:

                  The address of the  principal  business  office of each of the
Reporting Persons is 767 Fifth Avenue, New York, New York 10153.

Item 2(c)         Citizenship:

                  1) Perry Corp. is a New York corporation; and

                  2) Mr. Perry is a citizen of the United States.

Item 2(d)         Title of Class of Securities:

                  Common Stock, $0.0001 par value per share (the "Shares").

Item 2(e)         CUSIP Number:

                  040047102

Item 3.           If this statement is filed pursuant to Rule 13d-1(b), or 
                  13d-2(b) or (c), check whether the person filing is a:

                  i)  Perry Corp. is an investment adviser registered under
                      Section 203 of the Investment Advisers Act of 1940.

                  ii) Mr. Perry is a control person of Perry Corp.



CUSIP No. 040047102                                            Page 5 of 9 Pages


Item 4.           Ownership:

Item 4(a)         Amount Beneficially Owned:

                  As of the Date of Event,  each of the Reporting Persons may be
deemed to be the beneficial owner of 935,745 Shares.

Item 4(b)         Percent of Class:

                  As of the Date of Event, the number of Shares  outstanding was
35,320,808  according  to the  Issuer's  Quarterly  Report  on Form 10-Q for the
quarter  ended June 30,  2005 filed on August 4, 2005.  As of the Date of Event,
each of the  Reporting  Persons  may be  deemed  to be the  beneficial  owner of
approximately 2.6% of the total number of Shares outstanding.

Item 4(c)         Number of shares as to which such person has:

     Perry Corp.
     (i)     Sole power to vote or direct the vote                       935,745
     (ii)    Shared power to vote or to direct the vote                        0
     (iii)   Sole power to dispose or to direct the disposition of       935,745
     (iv)    Shared power to dispose or to direct the disposition of           0

     Mr. Perry
     (i)     Sole power to vote or direct the vote                       935,745
     (ii)    Shared power to vote or to direct the vote                        0
     (iii)   Sole power to dispose or to direct the disposition of       935,745
     (iv)    Shared power to dispose or to direct the disposition of

Item 5.           Ownership of Five Percent or Less of a Class:

                  If this statement is being filed to report the fact that as of
the date hereof the reporting  person has ceased to be the  beneficial  owner of
more than five percent of the class of securities, check the following [X].

Item 6.           Ownership of More than Five Percent on Behalf of Another 
                  Person:

                  The limited  partners of (or investors in) each of the private
investment funds for which Perry Corp. acts as general partner,  and/or managing
member of the  general  partner,  and/or  investment  adviser  have the right to
participate in the receipt of dividends  from, or proceeds from the sale of, the
securities  held for the accounts of their  respective  funds in accordance with
their respective  limited  partnership  interest (or investment  percentages) in
their respective funds.


CUSIP No. 040047102                                            Page 6 of 9 Pages


Item 7.           Identification and Classification of the Subsidiary Which 
                  Acquired the Security Being Reported on by the Parent
                  Holding Company:

                  Perry Corp. is the relevant  entity for which Mr. Perry may be
considered a control person.

                  Perry Corp.  is an  investment  adviser  registered  under the
Investment Advisers Act of 1940.

Item 8.           Identification and Classification of Members of the Group:

                  This Item 8 is not applicable.

Item 9.           Notice of Dissolution of Group:

                  This Item 9 is not applicable.

Item 10. Certification:

                  By signing below each of the Reporting Persons certifies that,
to the best of such person's  knowledge and belief,  the securities  referred to
above were acquired and are held in the ordinary course of business and were not
acquired  and are not held for the  purpose of or with the effect of changing or
influencing  the control of the Issuer of such  securities and were not acquired
and are not  held in  connection  with or as a  participant  in any  transaction
having such purpose or effect.




                                                               Page 7 of 9 Pages


                                   SIGNATURES


     After  reasonable  inquiry and to the best of my knowledge and belief,  the
undersigned  certifies that the information set forth in this statement is true,
complete and correct.


Date:    November 10, 2005                  PERRY CORP.

                                            By:/s/ Richard C. Perry
                                               ---------------------
                                               Name:  Richard C. Perry
                                               Title: President


Date:    November 10, 2005                  RICHARD C. PERRY

                                            /s/ Richard C. Perry
                                            ----------------------------





                                                               Page 8 of 9 Pages



                                  EXHIBIT INDEX
                                                                       Page No.
                                                                       --------
A.      Joint Filing Agreement, dated as of November 10, 2005, 
        by and among the Reporting Persons.....................            9






                                                               Page 9 of 9 Pages


                                    EXHIBIT A

                             JOINT FILING AGREEMENT

     The  undersigned  hereby agree that the  statement  on Schedule  13G/A with
respect to the common stock, $0.0001 par value, of Arena Pharmaceuticals,  Inc.,
dated as of  November  10,  2005 , is,  and any  amendments  thereto  (including
amendments on Schedule 13D) signed by each of the undersigned shall be, filed on
behalf of each of us pursuant to and in accordance  with the  provisions of Rule
13d-1(k) under the Securities Exchange Act of 1934.


Date:    November 10, 2005                  PERRY CORP.

                                            By:/s/ Richard C. Perry
                                               ---------------------
                                               Name:  Richard C. Perry
                                               Title: President


Date:    November 10, 2005                  RICHARD C. PERRY

                                            /s/ Richard C. Perry
                                            ----------------------------