Opexa to Present T-Cell Technology at Conference

The Woodlands, TX -- Opexa Therapeutics, Inc. (NASDAQ: OPXA), a company involved in the development and commercialization of cell therapies, today announced that Jim Williams, Ph.D., the Company's chief operating officer, research & development, will present at the Cambridge Healthtech Institute's Targeted Immunotherapeutics & Vaccines Summit on August 24, 2007 at 8:35 a.m. EDT.

Dr. Williams' presentation, "Paving the Way for Autologous Cell Therapy for Autoimmunity," will focus on Opexa's unique technology platform, which uses attenuated pathogenic T-cells, in the development of patient-specific immunotherapies for the treatment of autoimmune diseases amenable to T-cell based therapies. These diseases include multiple sclerosis, rheumatoid arthritis and Type 1 diabetes.

Slides of Dr. Williams' presentation will be posted to the Company's Web site shortly after the conclusion of his presentation.

The conference is being held August 21-24, 2007 at the Boston Marriott Cambridge Hotel in Cambridge, Mass.

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin. The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in treated patients.

Tovaxin is currently in a Phase IIb clinical trial. Patients treated in Opexa's Phase I/II open-label studies have experienced an approximately 90% average reduction in annualized relapse rate, minimal side effects and observed improvement in average EDSS scores.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin, a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus.