Catalyst catapults on FDA 'breakthrough' for rare autoimmune disease drug

Shares of Catalyst Pharmaceutical Partners catapulted 76% on 27 August on news the FDA granted breakthrough therapy designation to the Florida specialty pharma's experimental drug Firdapse (amifampridine phosphate), which is under investigation to treat symptoms associated with Lambert-Eaton Myasthenic syndrome (LEMS), a rare autoimmune disease, which results in muscle weakness, particularly in the legs and trunk.