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 immunity to myelin. 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 peripheral blood mononuclear cells (PBMC) 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 thawed, 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 immune profile or epitope shift to myelin epitopes over time.