Sec Form 13G Filing - Magnetar Financial LLC filing for ACER THERAPEUTICS INC. (ACER) - 2008-02-12

Insider filing report for Changes in Beneficial Ownership

  • Schedule 13G & 13D forms are used to report a party's ownership of stock which exceeds 5% of a company's total stock issue.
  • Schedule 13G is a shorter version of Schedule 13D with fewer reporting requirements.
"Insiders might sell their shares for any number of reasons, but they buy them for only one: they think the price will rise"
- Peter Lynch
What is insider trading>>

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



- --------------------------------------------------------------------------------


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. 1)*

                            OPEXA THERAPEUTICS, INC.
                            ------------------------
                                (Name of Issuer)

                     Common Stock, $0.50 par value per share
           -----------------------------------------------------------
                         (Title of Class of Securities)

                                    68372T103
                       -----------------------------------
                                 (CUSIP Number)

                                December 31, 2007
                      -------------------------------------
             (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  in 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 11 Pages
                            Exhibit Index: Page 10




                                 SCHEDULE 13G

CUSIP No.: 68372T103                                        Page 2 of 11 Pages


- ------------------------------------------------------------------------------
1.    Names of Reporting Persons.

      I.R.S. Identification Nos. of above persons (entities only).

      MAGNETAR FINANCIAL LLC
- ------------------------------------------------------------------------------
2. Check the Appropriate Box if a Member of a Group

      (a) [ ]
      (b) [ ]

- ------------------------------------------------------------------------------
3.    SEC Use Only
- ------------------------------------------------------------------------------
4.    Citizenship or Place of Organization

      Delaware
- ------------------------------------------------------------------------------
Number of           5.       Sole Voting Power                  0
Shares              ----------------------------------------------------------
Beneficially        6.       Shared Voting Power                0
Owned by Each       ----------------------------------------------------------
Reporting           7.       Sole Dispositive Power             0
Person With         ----------------------------------------------------------
                    8.       Shared Dispositive Power           0
- ------------------------------------------------------------------------------
9.    Aggregate Amount Beneficially Owned by Each Reporting Person

      0

- ------------------------------------------------------------------------------
10.   Check if the Aggregate  Amount in Row (9) Excludes  Certain  Shares (See
      Instructions)

      [  ]
- ------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

      0% based on 6,696,784 shares outstanding as of November 29, 2007.
- ------------------------------------------------------------------------------
12.   Type of Reporting Person:

      IA; OO


                                 SCHEDULE 13G

CUSIP No.: 68372T103                                        Page 3 of 11 Pages


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

      MAGNETAR CAPITAL PARTNERS LP
- ------------------------------------------------------------------------------
2.    Check the Appropriate Box if a Member of a Group
      (a) [ ]
      (b) [ ]
- ------------------------------------------------------------------------------
3.    SEC Use Only
- ------------------------------------------------------------------------------
4.    Citizenship or Place of Organization

      Delaware
- ------------------------------------------------------------------------------
Number of           5.       Sole Voting Power                  0
Shares              ----------------------------------------------------------
Beneficially        6.       Shared Voting Power                0
Owned by Each       ----------------------------------------------------------
Reporting           7.       Sole Dispositive Power             0
Person With         ----------------------------------------------------------
                    8.       Shared Dispositive Power           0
- ------------------------------------------------------------------------------
9.    Aggregate Amount Beneficially Owned by Each Reporting Person

      0
- ------------------------------------------------------------------------------
10.   Check if the Aggregate  Amount in Row (9) Excludes  Certain  Shares (See
      Instructions)

      [  ]
- ------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

      0% based on 6,696,784 shares outstanding as of November 29, 2007.
- ------------------------------------------------------------------------------
12.   Type of Reporting Person:

      HC; OO





                                 SCHEDULE 13G

CUSIP No.: 68372T103                                        Page 4 of 11 Pages


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

      SUPERNOVA MANAGEMENT LLC
- ------------------------------------------------------------------------------
2.    Check the Appropriate Box if a Member of a Group
      (a) [ ]
      (b) [ ]
- ------------------------------------------------------------------------------
3.    SEC Use Only
- ------------------------------------------------------------------------------
4.    Citizenship or Place of Organization

      Delaware
- ------------------------------------------------------------------------------
Number of           5.       Sole Voting Power                  0
Shares              ----------------------------------------------------------
Beneficially        6.       Shared Voting Power                0
Owned by Each       ----------------------------------------------------------
Reporting           7.       Sole Dispositive Power             0
Person With         ----------------------------------------------------------
                    8.       Shared Dispositive Power           0
- ------------------------------------------------------------------------------
9. Aggregate Amount Beneficially Owned by Each Reporting Person

      0
- ------------------------------------------------------------------------------
10.   Check if the Aggregate  Amount in Row (9) Excludes  Certain  Shares (See
      Instructions)

      [  ]
- ------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

      0% based on 6,696,784 shares outstanding as of November 29, 2007.
- ------------------------------------------------------------------------------
12.   Type of Reporting Person:

      HC; OO





                                 SCHEDULE 13G

CUSIP No.: 68372T103                                        Page 5 of 11 Pages


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

      ALEC N. LITOWITZ
- ------------------------------------------------------------------------------
2.    Check the Appropriate Box if a Member of a Group
      (a) [ ]
      (b) [ ]
- ------------------------------------------------------------------------------
3.    SEC Use Only
- ------------------------------------------------------------------------------
4.    Citizenship or Place of Organization

      United States of America
- ------------------------------------------------------------------------------
Number of           5.       Sole Voting Power                  0
Shares              ----------------------------------------------------------
Beneficially        6.       Shared Voting Power                0
Owned by Each       ----------------------------------------------------------
Reporting           7.       Sole Dispositive Power             0
Person With         ----------------------------------------------------------
                    8.       Shared Dispositive Power           0
- ------------------------------------------------------------------------------
9.    Aggregate Amount Beneficially Owned by Each Reporting Person

      0
- ------------------------------------------------------------------------------
10.   Check if the Aggregate  Amount in Row (9) Excludes  Certain  Shares (See
      Instructions)

      [  ]
- ------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

      0% based on 6,696,784 shares outstanding as of November 29, 2007.
- ------------------------------------------------------------------------------
12.   Type of Reporting Person:

      HC





                                                            Page 6 of 11 Pages


Item 1(a)   Name of Issuer:

            Opexa Therapeutics, Inc. (the "Issuer)

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

            2635 North Crescent Ridge Drive, The Woodlands, TX 77381.

Item 2(a)   Name of Person Filing:

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

            i)   Magnetar Financial LLC ("Magnetar Financial");

            ii)  Magnetar Capital Partners LP ("Magnetar Capital Partners");

            iii)  Supernova Management LLC ("Supernova Management"); and

            iv)  Alec N. Litowitz ("Mr. Litowitz").

            This Statement  relates to Shares (as defined herein) and warrants
("Warrants")  to acquire  Shares held for the  accounts  of  Magnetar  Capital
Master Fund, Ltd, a Cayman Islands exempted company  ("Magnetar Capital Master
Fund").  Magnetar  Financial is a registered  investment adviser under Section
203 of the Investment  Advisers Act of 1940, as amended (the "Advisers' Act").
Magnetar  Financial  serves as investment  adviser to Magnetar  Capital Master
Fund. In such capacity,  Magnetar  Financial  exercises  voting and investment
power over the Shares held for the account of Magnetar  Capital  Master  Fund.
Magnetar Capital Partners serves as the sole member and parent holding company
of Magnetar Financial. Supernova Management is the general partner of Magnetar
Capital Partners. The manager of Supernova Management is Mr. Litowitz.

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

            The address of the principal  business  office of each of Magnetar
Financial,  Magnetar Capital Partners,  Supernova Management, and Mr. Litowitz
is 1603 Orrington Avenue, 13th Floor, Evanston, Illinois 60201.

Item 2(c)   Citizenship:

            i)  Magnetar Financial is a Delaware limited liability company;

            ii) Magnetar Capital Partners is a Delaware limited partnership;

            iii) Supernova Management is a Delaware limited liability company;
                 and

            iv) Mr. Litowitz is a citizen of the United States of America.





                                                            Page 7 of 11 Pages


Item 2(d)   Title of Class of Securities: Common Stock, $0.50 par value per
share (the "Shares")

Item 2(e)   Cusip Number, 68372T103

Item 3      If This  Statement  is Filed  Pursuant  to  ss.ss.240.13d-1(b)  or
            240.13d-2(b) or (c), Check Whether the Person Filing is a:

            (a) [ ]     Broker or dealer  registered  under  Section 15 of the
                        Exchange Act.

            (b) [ ]     Bank as  defined in  Section  3(a)(6) of the  Exchange
                        Act.

            (c) [ ]     Insurance  company as defined in Section  3(a)(19)  of
                        the Exchange Act.

            (d) [ ]     Investment  company  registered under Section 8 of the
                        Investment Company Act.

            (e) [X]     An  investment   adviser  in   accordance   with  Rule
                        13d-1(b)(1)(ii)(E);

            (f) [ ]     An  employee   benefit  plan  or  endowment   fund  in
                        accordance with Rule 13d-1(b)(1)(ii)(F).

            (g) [ ]     A  parent   holding   company  or  control  person  in
                        accordance with Rule 13d-1(b)(1)(ii)(G).

            (h) [ ]     A savings  association  as defined in Section  3(b) of
                        the Federal Deposit Insurance Act.

            (i) [ ]     A church plan that is excluded from the  definition of
                        an investment  company  under Section  3(c)(14) of the
                        Investment Company Act.

Item 4.     Ownership:

Item 4(a)   Amount Beneficially Owned:

            As of  December 31,  2007  each of  Magnetar  Financial,  Magnetar
Capital  Partners,  Supernova  Management and Mr. Litowitz may be deemed to be
the beneficial  owner of 0 Shares held for the account of the Magnetar Capital
Master Fund.

Item 4(b)   Percent of Class:

            The number of Shares of which each of Magnetar Financial, Magnetar
Capital  Partners,  Supernova  Management and Mr. Litowitz may be deemed to be
the beneficial owner constitutes 0% of the total number of Shares  outstanding
(based  upon  information  provided  by  the  Issuer  in  its  recently  filed
regisration  statement on Form 10-QSB/A,  there were  approximately  6,696,784
shares outstanding as of November 29, 2007).





                                                            Page 8 of 11 Pages


Item 4(c)   Number of Shares of which such person has:

Magnetar Financial:
- -------------------

(i) Sole power to vote or direct the vote:                                    0

(ii) Shared power to vote or direct the vote:                                 0

(iii) Sole power to dispose or direct the                                     0
      disposition of:

(iv) Shared power to dispose or direct the                                    0
     disposition of:

Magnetar Capital Partners, Supernova Management, and Mr. Litowitz:
- ------------------------------------------------------------------

(i) Sole power to vote or direct the vote:                                    0

(ii) Shared power to vote or direct the vote:                                 0

(iii) Sole power to dispose or direct the                                     0
      disposition of:

(iv) Shared power to dispose or direct the                                    0
     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:

            This Item 6 is not applicable.


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

            See disclosure in Item 2 hereof.

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 their knowledge and belief, the securities  referred to above 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 the securities and were
not acquired and are not held in connection  with or as a  participant  in any
transaction having that purpose or effect.





                                                            Page 9 of 11 Pages


                                   SIGNATURE

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


Date: February 12, 2008              MAGNETAR FINANCIAL LLC

                                     By: Magnetar Capital Partners LP,
                                         As Sole Member



                                     By: /s/ Alec N. Litowitz
                                         -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager of Supernova Management
                                            LLC, as General Partner of
                                            Magnetar Capital Partners LP



Date:  February 12, 2008             MAGNETAR CAPITAL PARTNERS LP



                                     By: /s/ Alec N. Litowitz
                                         -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager of Supernova Management
                                            LLC, as General Partner of
                                            Magnetar Capital Partners LP

Date: February 12, 2008              SUPERNOVA MANAGEMENT LLC


                                     By: /s/ Alec N. Litowitz
                                         -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager



Date: February 12, 2008              ALEC N. LITOWITZ


                                     /s/ Alec N. Litowitz
                                     -----------------------------------









                                                            Page 10 of 11 Pages


                                 EXHIBIT INDEX


Ex.                                                                   Page No.
- ---                                                                   --------

A.    Joint Filing  Agreement,  dated February 12, 2008 by and among
      Magnetar   Financial  LLC,   Magnetar   Capital  Partners  LP,
      Supernova Management LLC, and Alec N. Litowitz ................       11





                                                           Page 11 of 11 Pages


                                   EXHIBIT A

                            JOINT FILING AGREEMENT

      The  undersigned  hereby  agree that the  statement on Schedule 13G with
respect to the Common Stock of Opexa  Therapeutics,  Inc. dated as of February
12, 2008 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, as amended.



Date: February 12, 2008              MAGNETAR FINANCIAL LLC

                                     By: Magnetar Capital Partners LP,
                                         As Sole Member



                                     By:    /s/ Alec N. Litowitz
                                            -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager of Supernova Management
                                            LLC, as General Partner of
                                            Magnetar Capital Partners LP



Date: February 12, 2008              MAGNETAR CAPITAL PARTNERS LP



                                     By:    /s/ Alec N. Litowitz
                                            -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager of Supernova Management
                                            LLC, as General Partner of
                                            Magnetar Capital Partners LP



Date: February 12, 2008              SUPERNOVA MANAGEMENT LLC


                                     By:    /s/ Alec N. Litowitz
                                            -----------------------------------
                                     Name:  Alec N. Litowitz
                                     Title: Manager



Date: February 12, 2008              ALEC N. LITOWITZ


                                     /s/ Alec N. Litowitz
                                     -----------------------------------------