Two years after Tcelna failed a Phase II trial in relapsing-remitting multiple sclerosis, Opexa Therapeutics Inc. has restarted development of the cell therapy with a new focus on secondary progressive MS. The company is going after later stage, active disease because the cell therapy's mode of action suggests it is more effective in that setting.

The autologous cell therapy contains myelin reactive T cells (MRTCs) primed and expanded ex vivo with myelin basic protein (MBP), proteolipid protein 1 (PLP1) and myelin oligodendrocyte glycoprotein (MOG). These proteins are expressed on the surface of MRTCs - the cells that destroy the myelin sheath in MS patients.