Opexa Therapeutics to Present Progress on Development of Monocyte-Derived Pancreatic Islet Cells for Diabetes.

Abstracts accepted for presentation at the 13th Annual Meeting of the International Society for Cellular Therapy June 24-27, 2007, in Sydney, Australia, and 5th International Society for Stem Cell Research Annual Meeting June 17-20, 2007, in Cairns, Queensland, Australia

THE WOODLANDS, Texas -- Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, will make presentations at two scientific meetings in Australia in June that demonstrate significant advancement of Opexa's human stem cell program to develop human monocyte-derived stem cell therapies for the treatment of human diseases such as diabetes.

5(th) International Society for Stem Cell Research Annual Meeting (ISSCR)

The presentation by Opexa's scientist Glenn Winnier, Ph.D., at the ISSCR Annual Meeting in Cairns, Queensland, Australia, from June 17-20, 2007, will describe the differentiation of monocyte-derived stem cells (MDSCs) to generate pancreatic endocrine cell clusters known as MDIs. MDIs express pancreatic-specific factors as well as hormones insulin, glucagons and somatostatin in physiological proportions. These studies also demonstrated that MDIs function in a glucose-responsive manner when transplanted into diabetic animals. Study animals demonstrate a prolonged reduction (greater than 60 days) in blood glucose levels when MDIs were transplanted under the kidney capsule of stz-induced Nod/scid mice.

13(th) Annual Meeting of the International Society for Cellular Therapy (ISCT)

Opexa has developed novel processes for deriving monocyte-derived stem cells (MDSC) from peripheral blood from healthy human subjects and further differentiating MDSCs into insulin-producing, islet-like clusters. The Company's recent research activities have resulted in successfully generating monocyte-derived islets (MDIs) from insulin-dependent type 1 and type 2 diabetics. These insulin-producing, islet-like clusters express insulin, glucagon and somatostatin characteristic hormones found in pancreatic islets and function in a glucose-responsive manner. These recent developments will be presented at the 13th Annual Meeting of the International Society for Cellular Therapy from June 24-27, 2007, in Sydney, Australia.

"This work represents a major step forward in the preclinical development of autologous source of cells for the treatment of diabetes," stated Dr. Glenn Winnier, Director of Molecular Biology.

David McWilliams, president and chief executive officer of Opexa, commented, "We are pleased with the progress of our monocyte-derived stem cell program and believe our islet replacement therapy represents a cost-efficient approach that may advance the treatment of diabetes through the transplantation of a patient's own MDIs. We are looking forward to continuing to advance this technology."

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(TM), 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. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.