THIRD AMENDMENT TO AMENDED AND RESTATED LICENSE AGREEMENT

                                                                    Exhibit 10.1

                               THIRD AMENDMENT TO
                     AMENDED AND RESTATED LICENSE AGREEMENT


     This Third Amendment to Amended and Restated License Agreement ("Third
Amendment") effective this 27th day of October, 2006 is between the University
of Chicago, an Illinois not-for-profit corporation ("UNIVERSITY"), having its
principal office at 5555 S. Woodlawn Avenue, Chicago, IL 60637 and Opexa
Therapeutics, Inc., a Texas corporation ("OPEXA") (formerly named
PharmaFrontiers Corp.) having its principal office at 2635 N. Crescent Ridge
Drive, The Woodlands, Texas 77381. Each hereunder may be referred to separately
as the ("Party"), or together as the ("Parties"). The Parties agree:

                                    RECITALS

A.    UNIVERSITY and PHARMAFRONTIERS have previously entered into an "Amended and
     Restated License Agreement" dated December 30, 2004 (the "License
     Agreement"); and

B.    UNIVERSITY and PHARMAFRONTIERS have previously entered into a "First
     Amendment to Amended and Restated License Agreement" dated October 31, 2005
     (the "First Amendment") and a "Second Amendment to Amended and Restated
     L