Investors hit Catalyst Pharmaceuticals Inc. hard on Feb. 17, driving shares down 50%, after the company disclosed the FDA refused to file (RTF) the Florida firm's new drug application (NDA) for Firdapse (amifampridine phosphate), a 3,4-diaminopyridine phosphate, as a symptomatic treatment for two very rare neuromuscular diseases – Lambert Eaton myasthenic syndrome (LEMS) and congenital myasthenic syndromes (CMS).
The Catalyst stock ended the day at $1.16, down 69 cents, or a loss of 37.3%.