SC 13G 1 efc6-1935_5908257formsc13g.txt UNITED STATES SECURITIES EXCHANGE COMMISSION Washington, D.C. 20549 -------------------------------------------------------------------------------- SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. ) OPEXA THERAPEUTICS, INC. ------------------------ (Name of Issuer) Common Stock, $.05 par value per share -------------------------------------- (Title of Class of Securities) 68372T103 ---------------------- (CUSIP Number) June 20, 2006 ---------------------- (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 Shares 5. Sole Voting Power 668,315 /1/ Beneficially Owned ........ ................................................. by Each Reporting 6. Shared Voting Power None Person With ........ ................................................. 7. Sole Dispositive Power 668,315 /1/ ........ ................................................. 8. Shared Dispositive Power None ......... ...................................................................... 9. Aggregate Amount Beneficially Owned by Each Reporting Person 668,315 /1/ ......... ...................................................................... 10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] ......... ...................................................................... 11. Percent of Class Represented by Amount in Row (9) 9.9% based on 6,696,904 shares outstanding as of June 19, 2006. ......... ...................................................................... 12. Type of Reporting Person: IA; OO -------------------------------- /1/ In addition, the Reporting Person may also be deemed to be the beneficial owner of certain warrants to acquire Shares. The warrants, which are exercisable immediately at the option of the holder, are subject to so-called "blocker" provisions prohibiting the holder from exercising the warrants to the extent that such exercise would result in the holder being deemed the beneficial owner of more than 9.99% of the Shares then issued and outstanding. See Item 4(a) herein. 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 Shares 5. Sole Voting Power None Beneficially Owned by Each Reporting Person With ........ ................................................. 6. Shared Voting Power 668,315 /1/ ........ ................................................. 7. Sole Dispositive Power None ........ ................................................. 8. Shared Dispositive Power 668,315 /1/ ......... ...................................................................... 9. Aggregate Amount Beneficially Owned by Each Reporting Person 668,315 /1/ ......... ...................................................................... 10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] ......... ...................................................................... 11. Percent of Class Represented by Amount in Row (9) 9.9% based on 6,696,904 shares outstanding as of June 19, 2006. ......... ...................................................................... 12. Type of Reporting Person: HC; OO -------------------------------- /1/ In addition, the Reporting Person may also be deemed to be the beneficial owner of certain warrants to acquire Shares. The warrants, which are exercisable immediately at the option of the holder, are subject to so-called "blocker" provisions prohibiting the holder from exercising the warrants to the extent that such exercise would result in the holder being deemed the beneficial owner of more than 9.99% of the Shares then issued and outstanding. See Item 4(a) herein. 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 Shares 5. Sole Voting Power None Beneficially Owned by Each Reporting Person With ........ ................................................. 6. Shared Voting Power 668,315 /1/ ........ ................................................. 7. Sole Dispositive Power None ........ ................................................. 8. Shared Dispositive Power 668,315 /1/ ......... ...................................................................... 9. Aggregate Amount Beneficially Owned by Each Reporting Person 668,315 /1/ ......... ...................................................................... 10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] ......... ...................................................................... 11. Percent of Class Represented by Amount in Row (9) 9.9% based on 6,696,904 shares outstanding as of June 19, 2006. ......... ...................................................................... 12. Type of Reporting Person: HC; OO -------------------------------- /1/ In addition, the Reporting Person may also be deemed to be the beneficial owner of certain warrants to acquire Shares. The warrants, which are exercisable immediately at the option of the holder, are subject to so-called "blocker" provisions prohibiting the holder from exercising the warrants to the extent that such exercise would result in the holder being deemed the beneficial owner of more than 9.99% of the Shares then issued and outstanding. See Item 4(a) herein. 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 Shares 5. Sole Voting Power None Beneficially Owned by Each Reporting Person With ........ ................................................. 6. Shared Voting Power 668,315 /1/ ........ ................................................. 7. Sole Dispositive Power None ........ ................................................. 8. Shared Dispositive Power 668,315 /1/ ......... ...................................................................... 9. Aggregate Amount Beneficially Owned by Each Reporting Person 668,315 /1/ ......... ...................................................................... 10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] ......... ...................................................................... 11. Percent of Class Represented by Amount in Row (9) 9.9% based on 6,696,904 shares outstanding as of June 19, 2006. ......... ...................................................................... 12. Type of Reporting Person: HC -------------------------------- /1/ In addition, the Reporting Person may also be deemed to be the beneficial owner of certain warrants to acquire Shares. The warrants, which are exercisable immediately at the option of the holder, are subject to so-called "blocker" provisions prohibiting the holder from exercising the warrants to the extent that such exercise would result in the holder being deemed the beneficial owner of more than 9.99% of the Shares then issued and outstanding. See Item 4(a) herein. 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, Houston, 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 controlling member 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, $.05 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: Magnetar Financial is a registered investment adviser under Section 203 of the Advisers' Act. Item 4. Ownership: Item 4(a). Amount Beneficially Owned: As of July 10, 2006, each of Magnetar Financial, Magnetar Capital Partners, Supernova Management and Mr. Litowitz may be deemed to be the beneficial owner of 668,315 Shares held for the account of the Magnetar Capital Master Fund. In addition, each of Magnetar Financial, Magnetar Capital Partners, Supernova Management and Mr. Litowitz may also be deemed to beneficially own the Shares issuable upon the exercise of the Warrants held for the account of Magnetar Capital Master Fund. The Warrants contain a contractual provision blocking exercise of the Warrants when the holder beneficially owns more than 9.99% of the issued and outstanding Shares. Since the Reporting Persons currently may be deemed to beneficially own 9.9% of the Shares, the Warrants are not currently exercisable and thus, the Shares underlying the Warrants have not been included in the calculations of the Reporting Person's beneficial ownership of the Shares. 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 approximately 9.9% of the total number of Shares outstanding (based upon information provided by the Issuer in its Rule 424(b) prospectus filed recently with the Securities and Exchange Commission, there were approximately 6,696,904 shares outstanding as of June 19, 2006). Item 4(c) Number of Shares of which such person has: Magnetar Financial: ------------------- (i) Sole power to vote or direct the vote: 668,315 (ii) Shared power to vote or direct the vote: 0 (iii) Sole power to dispose or direct the disposition of: 668,315 (iv) Shared power to dispose or direct the disposition of: 0 Page 8 of 11 Pages 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: 668,315 (iii) Sole power to dispose or direct the disposition of: 0 (iv) Shared power to dispose or direct the disposition of: 668,315 Item 5. Ownership of Five Percent or Less of a Class: This Item 5 is not applicable. 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: July 10, 2006 MAGNETAR FINANCIAL LLC By: Magnetar Capital Partners LP, As Sole Member By: Supernova Management LLC, As General Partner By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 MAGNETAR CAPITAL PARTNERS LP By: Supernova Management LLC, As General Partner By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 SUPERNOVA MANAGEMENT LLC By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 ALEC N. LITOWITZ /s/ Alec N. Litowitz ------------------------------ Page 10 of 11 Pages EXHIBIT INDEX Ex. Page No. --- -------- A. Joint Filing Agreement, dated July 10, 2006 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 July 10, 2006 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: July 10, 2006 MAGNETAR FINANCIAL LLC By: Magnetar Capital Partners LP, As Sole Member By: Supernova Management LLC, As General Partner By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 MAGNETAR CAPITAL PARTNERS LP By: Supernova Management LLC, As General Partner By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 SUPERNOVA MANAGEMENT LLC By: /s/ Alec N. Litowitz --------------------------- Name: Alec N. Litowitz Title: Manager Date: July 10, 2006 ALEC N. LITOWITZ /s/ Alec N. Litowitz ------------------------------