Opexa Briefs Shareholders on Corporate Update

BusinessWire, January 20, 2009

The Texas-based stem cell company Opexa Therapeutics, Inc., which is focused on the development of patient-specific cellular therapies for the treatment of autoimmune diseases such as multiple sclerosis and diabetes, today offered a corporate update to its employees, shareholders and the general public.

Perhaps most notable on the list of topics to be addressed was the TERMS (Tovaxin for Early Relapsing Multiple Sclerosis) study that commenced in October of 2008, and which is a Phase IIb multi-center, randomized, double-blind placebo-controlled clinical trial in which 150 patients with the relapsing-remitting form of multiple sclerosis were treated with Tovaxin. The primary efficacy endpoint will measure the "Cumulative number of gadolinium-Enhanced brain Lesions" (CELs) via MRI scans at 28, 36, 44 and 52 weeks, while secondary efficacy endpoints will measure annualized relapse rare (ARR) and new CELs at weeks 28 through 52, as well as the T2-weighted lesion volume when compared to the baseline. Although a comprehensive analysis of the study will be conducted over the next several months, initial data collected thus far are encouraging.

Additionally, a number of discussions are ongoing for various partnerships between Opexa and other companies, such as for the further development of its lead therapy, Tovaxin, as well as of other novel therapies for the treatment for multiple sclerosis, with the anticipation of pivotal trials and future commercialization. A number of possible partnerships are also currently in discussion for the development and commercialization of Opexa's stem cell therapy to treat Types 1 and 2 diabetes, such as its monocyte-derived stem cells (MDSCs) and monocyte derived pancreatic-like islets (MDI) as a potential therapeutic transplantation product in the treatment of diabetes. Additionally, Opexa has developed proprietary in vitro processes for the derivation of MDSCs from blood monocytes which are then expanded ex vivo and converted to MDI for transplantation into the hepatic main portal vein of diabetic patients. Currently, there is a strong emphasis at Opexa for the further development of MDSC technology as a platform for autologous transplantation therapy in the treatment of diabetic patients via the ex vivo generation of MDIs. Unlike most multipotent stem cells, MDSCs exhibit a specific time-dependent expression of markers that distinguish them from other cells, and which have been shown to differentiate into hematopoietic, epithelial, endothelial, endocrine and neuronal cells.

According to Dr. Dawn McGuire, a neurologist and member of Opexa's Clinical Advisory Board, "Tovaxin offers the potential for immunomodulatory treatment that is exquisitely individualized for a complex disease that manifests in a highly individual manner. Early results with Tovaxin suggest reduction not only in relapse rates but also in global neuronal loss among patients with the most active disease. I see great promise here."

Opexa also announced the resignation of COO Dr. Jim Williams, effective February 13, 2009, after which time Dr. Williams will remain actively involved with Opexa in a consulting capacity. According to Neil Warma, president and CEO of Opexa Therapeutics, "With possibly the safest therapy for MS demonstrated to date and some very encouraging efficacy data in clinically relevant relapse rates and disability scores, we are pleased with the level of discussions we are having with potential partners. We are extremely fortunate to have someone of Dr. McGuire's experience to further advise on our clinical development strategy and steward the clinical development of Tovaxin. Her substantial knowledge and experience in MS, having overseen the early development of Tysabri, will certainly contribute very favorably to our development program and partnering discussions. We are grateful to Jim for having contributed immensely to the development of Tovaxin to date and for overseeing the management of the first-in-class TERMS IIb study and we are pleased he will remain a consultant to the company as we continue forward with our clinical strategy."

An individualized T-cell therapeutic vaccine which combats the characteristic demyelination of nerve fibers in the central nervous systems of people with multiple sclerosis, Tovaxin consists of attenuated patient-specific myelin-reactive T-cells against peptides of proteins from myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG) and proteolipid protein (PLP) or combinations thereof.

Tovaxin's dual mechanism of action has been shown to exhibit, on the one hand, an anti-idiotypic effect which induces an immune response that depletes and regulates the circulating pathogenic myelin-reactive T-cells that attack the myelin sheath of nerve fibers, and, on the other hand, an anti-ergotypic effect which rebalances the overall immune system by causing a shift from pathogenic inflammatory T-cells to anti-inflammatory T-cells.