-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001310880-08-000001.txt : 20080813
<SEC-HEADER>0001310880-08-000001.hdr.sgml : 20080813
<ACCEPTANCE-DATETIME>20080813122521
ACCESSION NUMBER:		0001310880-08-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080811
FILED AS OF DATE:		20080813
DATE AS OF CHANGE:		20080813

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Opexa Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001069308
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				760333165
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2635 N. CRESCENT RIDGE DRIVE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77381
		BUSINESS PHONE:		(281) 272-9331

	MAIL ADDRESS:	
		STREET 1:		2635 N. CRESCENT RIDGE DRIVE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77381

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PharmaFrontiers Corp.
		DATE OF NAME CHANGE:	20051011

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PHARMAFRONTIERS CORP
		DATE OF NAME CHANGE:	20040816

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SPORTAN UNITED INDUSTRIES INC
		DATE OF NAME CHANGE:	19990305

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hung David
		CENTRAL INDEX KEY:			0001310880

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33004
		FILM NUMBER:		081012296

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		4155433470

	MAIL ADDRESS:	
		STREET 1:		501 SECOND STREET
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94107
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001069308</issuerCik>
        <issuerName>Opexa Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>opxa</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001310880</rptOwnerCik>
            <rptOwnerName>Hung David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>501 SECOND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94107</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15105</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.655</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>47005</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.78</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15105</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.78</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-02-11</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-08-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15105</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70105</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>David Hung</signatureName>
        <signatureDate>2008-08-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----