Sec Form 13G Filing - MARXE AUSTIN W & GREENHOUSE DAVID M filing for ACER THERAPEUTICS INC. (ACER) - 2010-10-12

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.
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UNITED STATES
SECURITIES AND 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
                  _______________________________________________
(Title of Class of Securities)

68372T103
                 _________________________________________________
(CUSIP Number)


		with a copy to:
Austin W. Marxe		Allen B. Levithan, Esq.
527 Madison Avenue, Suite 2600		Lowenstein Sandler PC
New York, New York 10022		65 Livingston Avenue
			Roseland, New Jersey 07068
			(973) 597-2406
(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

September 30, 2010
(Date of Event which Requires Filing of this Statement)


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

	____	Rule 13d-1(b)
	_x__	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
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).



Cusip No. 68372T103       13G                           Page 2 of 6 Pages
1.Names of Reporting Persons.  I.R.S. Identification Nos. of above persons
(entities only):

	Austin W. Marxe and David M. Greenhouse

2.	Check the Appropriate Box if a Member of a Group (See Instructions):
	(a)	[    ]	 	Not Applicable
	(b)	[    ]

	3.	SEC Use Only

	4.	Source of Funds (See Instructions):  00

	5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to
Items 2(d) or 2(e):
				Not Applicable

	6.	Citizenship or Place of Organization:	    United States

	Number of	7.	Sole Voting Power:	0
	Shares Beneficially	8.	Shared Voting Power:	860,800*
	Owned by
	Each Reporting	9.	Sole Dispositive Power:	0
	Person With	10.	Shared Dispositive Power: 860,800*____

	11.	Aggregate Amount Beneficially Owned by Each Reporting Person:
         860,800*

	12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares
		(See Instructions):		               Not Applicable

	13.	Percent of Class Represented by Amount in Row (11):     4.5%*

	14.	Type of Reporting Person (See Instructions):       IA, IN


* This is a joint filing by Austin W. Marxe (?Marxe?) and David M. Greenhouse
(?Greenhouse?).  Marxe and Greenhouse share sole voting and investment power
over 0 shares of Common Stock and 546,750 Warrants to purchase 139,050 shares
of Common Stock owned by Special Situations Cayman Fund, L.P., 0 shares of
Common Stock and 1,936,250 Warrants to purchase 446,750 shares of Common Stock
owned by Special Situations Fund III QP, L.P., 2,000,000 Warrants to purchased
200,000 shares of Common Stock owned by Special Situations Private Equity
Fund, L.P. and 750,000 Warrants to purchase 75,000 shares of Common Stock
owned by Special Situations Life Sciences Fund, L.P. See Items 2 and 4 of this
Schedule for additional information.


								Page 3 of 6 Pages
Item 1.	Security and Issuer:
	(a) Opexa Therapeutics, Inc.(Formally Pharma Frontiers Corp)
	(b) 2635 N. Crescent Ridge Drive
                The Woodlands, Texas 77381

Item 2. (a)	Name of Person Filing:
	The persons filing this report are Austin W. Marxe (?Marxe?) and
David M. Greenhouse (?Greenhouse?), who are the controlling principals of AWM
Investment Company, Inc. (?AWM?), the general partner of and investment
adviser to Special Situations Cayman Fund, L.P. (?Cayman?).  AWM also serves
as the general partner of MGP Advisers Limited Partnership (?MGP?), the
general partner of Special Situations Fund III QP, L.P. (?SSFQP?). Marxe and
Greenhouse are members of MG Advisers L.L.C. the general partner of Special
Situations Private Equity Fund, L.P. (?SSPE?). Marxe and Greenhouse are also
members of LS Advisers L.L.C. the general partner of Special Situations Life
Sciences Fund, L.P. (?Life Sciences?).  AWM serves as the investment adviser
to SSFQP, SSPE and Life Sciences. (SSFQP, Cayman, SSPE and Life Sciences will
hereafter be referred to as, the ?Funds?).  The principal business of each
Fund is to invest in equity and equity-related securities and other securities
of any kind or nature.

             (b) Address of Principal Business Office or, if none, Residence:

	The principal business address for Marxe and Greenhouse is 527
Madison Avenue, Suite 2600, New York, NY  10022.


              (c) Citizenship:

       	           Austin W. Marxe and David M. Greenhouse are United
States citizens.

              (d) Title of Class of Securities:  Common Stock
	              (e) CUSIP Number:  68372T103.

Item 3.     If this statement is filed pursuant to $240.13d-1(b) or 240.13d-
2(b), check whether
            the person filing is a:    Not Applicable

(a) ( )	Broker or Dealer registered under section 15 of the Act;
(b) ( )	Bank as defined in section 3(a) (6) of the Act;
(c) ( )	Insurance Company as defined in section 3(a) (19) of the Act;
(d) ( )	Investment Company registered under section 8 of the Investment
Company Act of 1940;
(e) ( )	An Investment Adviser in accordance with $240.13d
		-1(b)(I)(ii)(E);
(f) ( )	An employee benefit plan or endowment fund in accordance with
$240.13d-1(b)(I)(ii)(F);


								Page 4 of 6 Pages

(g) ( )	A parent holding company or control person in accordance with
$240.13d-
	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 of 1940;
(j) ( )   	Group, in accordance with $240.13d-1(b)(1)(ii)(J).


Item 4.       Ownership:

	 (a) Amount Beneficially Owned:  Messrs. Marxe and Greenhouse
beneficially own a total of 0 shares of Common Stock and 5,233,000 Warrants to
purchase 860,800 shares of Common Stock. This amount includes 0 shares of
Common Stock and 546,750 Warrants to purchase 139,050 shares of Common Stock
owned by Cayman, 0 shares of Common Stock and 1,936,250 Warrants to purchase
446,750 shares of Common Stock owned by SSFQP, 2,000,000 Warrants to purchase
200,000 shares of Common Stock owned by SSPE and 750,000 Warrants to purchase
75,000 shares of Common Stock owned by Life Sciences.

	(b) Percent of Class:  Messrs. Marxe and Greenhouse beneficially own
4.5% of the shares outstanding.  Cayman owns 0.8% of the outstanding shares,
SSFQP owns 2.4% of the outstanding shares, SSPE owns 1.1% of the outstanding
shares and Life Sciences owns 0.4% of the outstanding shares.

	(c) Number of Shares as to which the person has:

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

		(ii)	Shared power to vote or to direct the vote:  860,800
		(iii)	Sole power to dispose or to direct the disposition of:  0

(iv)	Shared power to dispose or to direct the disposition of:
860,800


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 that five percent of the class
of securities, check the following _X__.

Item 6.Ownership of More than Five Percent on Behalf of Another Person:  Not
Applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the
Security being Reported on By the Parent Holding Company:  Not Applicable.

Item 8. Identification and Classification of Members of the Group:  Not
applicable

Item 9. Notices of Dissolution of Group:  Not applicable.




Page 5 of 6 Pages

Item 10.Certification:

	By signing below I certify that, to the best of my 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 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.



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.


Dated: October 8, 2010


				/s/ Austin W. Marxe
				AUSTIN W. MARXE



				/s/David M Greenhouse
				DAVID M. GREENHOUSE




Attention:  Intentional misstatements or omissions of fact constitute Federal
criminal violations (See 18 U.S.C. 1001).






















       Page 6 of 6 Pages


JOINT FILING AGREEMENT


	Austin W. Marxe and David M. Greenhouse hereby agree that the Schedule
13G to which this agreement is attached is filed on behalf of each of them.




	/s/_Austin W. Marxe
Austin W. Marxe



	/s/_David M. Greenhouse
David M. Greenhouse




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S5313/1
1319328.02