T-cell platform

Opexa's initial disease targets are autoimmune diseases amenable to T-cell based therapies, such as Multiple Sclerosis (MS). Opexa has developed a proprietary T-cell technology platform that allows for the production of patient-specific T-cell therapies that induce therapeutic immune responses to combat a variety of autoimmune diseases. Tcelna, Opexa's lead therapeutic candidate for the treatment of MS is based on this platform. Tcelna is a personalized autologous immunotherapy that is not only manufactured for every individual patient but also is tailored to match each patient's evolving disease profile. Tcelna consists of attenuated, patient-specific myelin reactive T-cells (MRTCs) against peptides of the three primary myelin proteins [Myelin basic protein (MBP), Myelin oligodendrocyte glycoprotein (MOG) and Proteolipid protein (PLP)] that have been implicated in T-cell pathogenesis of MS.

Tcelna is manufactured for a patient by the ImmPath™ process, Opexa's proprietary manufacturing process. In the initial step, the patient-specific MRTCs causing the disease are isolated from the blood and expanded in culture with specific peptides identified by assaying peripheral blood mononuclear cell (PBMC) reactivity against 109 peptides derived from MBP, MOG and PLP in the presence of antigen-presenting cells and growth factors. Myelin-peptide reactive T-cells are grown to therapeutic levels and cryopreserved. Prior to use, the MRTCs are expanded, formulated, and attenuated (by irradiation) to render them unable to replicate but viable for therapy. These attenuated T-cells are administered in a defined schedule of five subcutaneous injections. Patients are expected be treated with a new series of Tcelna (5 doses) each year based on their altered disease profile or epitope shift.

Stem cell platform

Opexa has also developed a proprietary adult stem cell technology to produce monocyte-derived stem cells (MDSC) from blood. These MDSC can be derived from a patient's monocytes, expanded ex vivo, and then administered to the same patient. Our initial focus is the further development of this monocyte-derived stem cell technology as a platform for the in vitro generation of highly specialized cells for potential application in autologous cell therapy for patients with diabetes mellitus.

A proprietary in vitro process has been developed to derive MDSC from blood monocytes, expand them ex vivo, and then convert them to MDIs for transplantation into the hepatic main portal vein of diabetic patients. The Company believes that because this is an adult autologous therapy there should be no rejection issues therefore avoiding the use of anti-rejection drugs.

We believe we have demonstrated that the MDSCs are multipotent stem cells that may be cultured under defined conditions to convert them into several cellular lineages. The diabetes program is in an early (pre-clinical) development stage.