Dr. Mark Freedman to Join Opexa's Scientific Advisory Board

Leading Worldwide Expert in Multiple Sclerosis Brings Significant Expertise to Tovaxin® Clinical Development Program

THE WOODLANDS, Texas (September 12, 2022) Opexa Therapeutics, Inc. (NASDAQ: OPXA), a company developing Tovaxin®, a novel T-cell therapy for multiple sclerosis (MS), today announced it has recently added a key international opinion leader to its Scientific Advisory Board. Mark Freedman, M.D., is a professor of medicine in the field of neurology at the University of Ottawa, and director of the Multiple Sclerosis Research Unit at the Ottawa Hospital, General Campus. He will be joining other colleagues of high regard on Opexa's Scientific Advisory Board: Dawn McGuire, M.D. (Chair), Doug Arnold, M.D., Edward Fox, M.D., Ph.D., Hans-Peter Hartung, M.D., Clyde Markowitz, M.D., Paul O'Connor, M.D., and Arthur Vandenbark, Ph.D.

"It is a distinct pleasure to welcome Dr. Freedman to Opexa's Scientific Advisory Board," stated Dr. McGuire, Chair of the SAB. "Dr. Freedman is internationally renowned for his expertise in MS translational research and has been involved in numerous clinical trials in patients with MS. We will benefit greatly from his clinical and scientific insights as we move to the next phase of Tovaxin development for MS."

"As a neuroimmunologist, I have carefully followed Opexa's technology for some time and have always been intrigued about this novel approach to treating MS patients," commented Dr. Freedman. "As a personalized and targeted therapy with an excellent safety profile, Tovaxin may prove to be a differentiated product for the treatment of both Relapsing Remitting and Secondary Progressive MS patients. I look forward to using my knowledge and experience to guide the Company in their efforts to further develop Tovaxin for patients with MS."

Mark Freedman, M.D. Bio

Dr. Freedman is currently professor of medicine in the field of neurology at the University of Ottawa, as well as director of the Multiple Sclerosis Research Unit at the Ottawa Hospital, General Campus. He holds his specialist certification in Quebec CSPQ and all of Canada FRCP(C) and is a Fellow of the American Academy of Neurology (FAAN).

Dr. Freedman has published extensively and his research includes the area of molecular neurochemistry, cellular immunology and clinical studies in MS. In addition, he has over 25 years of experience in the management of patients with MS and has been principal investigator, steering committee member and DSMB member on numerous clinical trials with new therapeutic agents for MS.

Dr. Freedman is also active on several national and international committees including the Multiple Sclerosis Society of Canada, National MS Society (USA), the Americas Committee for Treatment and Research in MS (ACTRIMS) and the Consortium of MS Centres (CMSC). He is the immediate past president of the Canadian Network of MS Clinics.

About Opexa

Opexa Therapeutics, Inc. is dedicated to the development of patient-specific cellular therapies for the treatment of autoimmune diseases. The Company's leading therapy, Tovaxin®, is a personalized cellular immunotherapy treatment that is in late stage clinical development for MS. Tovaxin is derived from T-cells isolated from peripheral blood, expanded ex vivo, and reintroduced into the patients via subcutaneous injections. This process triggers a potent immune response against specific subsets of autoreactive T-cells known to attack myelin and, thereby, reduces the risk of relapse over time.

Opexa is preparing for a Phase III clinical trial with Tovaxin in Relapsing-Remitting Multiple Sclerosis (RRMS) following the completion of a Phase IIb clinical study in 150 patients with MS. Data from this clinical study show evidence that RRMS patients treated with Tovaxin saw overall clinical and disability benefits over the placebo group, including a clinically relevant decrease in the Annualized Relapse Rate (ARR), and improvement in disability score (EDSS), as well as an excellent safety profile with no serious adverse events related to Tovaxin treatment. In addition, Opexa is evaluating opportunities to advance Tovaxin through clinical development in Secondary Progressive Multiple Sclerosis (SPMS), an area with high unmet medical need.

For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com

Cautionary Statement Relating to Forward - Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The words "expects," "believes," "anticipates," "estimates," "may," "could," "intends," "exploring," "evaluating" and similar expressions are intended to identify forward-looking statements. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding the development of the Company's product candidate, Tovaxin, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: our capital position, the ability of the Company to enter into and benefit from a partnering arrangement for the Company's product candidate, Tovaxin, on reasonably satisfactory terms (if at all), our dependence (if partnered) on the resources and abilities of any partner for the further development of Tovaxin, our ability to compete with larger, better financed pharmaceutical and biotechnology companies, new approaches to the treatment of our targeted diseases, our expectation of incurring continued losses, our uncertainty of developing a marketable product, our ability to raise additional capital to continue our treatment development programs and to undertake and complete any further clinical studies for Tovaxin, the success of our clinical trials, the efficacy of Tovaxin for any particular indication, such as for RRMS or SPMS, our ability to develop and commercialize products, our ability to obtain required regulatory approvals, our compliance with all Food and Drug Administration regulations, our ability to obtain, maintain and protect intellectual property rights (including for Tovaxin), the risk of litigation regarding our intellectual property rights, the success of third party development and commercialization efforts with respect to products covered by intellectual property rights transferred by the Company, our limited manufacturing capabilities, our dependence on third-party manufacturers, our ability to hire and retain skilled personnel, our volatile stock price, and other risks detailed in our filings with the Securities and Exchange Commission. These forward-looking statements speak only as of the date made. We assume no obligation or undertaking to update any forward-looking statements to reflect any changes in expectations with regard thereto or any change in events, conditions or circumstances on which any such statement is based. You should, however, review additional disclosures we make in our reports filed with the Securities and Exchange Commission, including our Annual Report on Form 10 K for the year ended December 31, 2010.