Catalyst Pharmaceuticals Inc., of Coral Gables, Fla., reached an agreement with the FDA for a special protocol assessment for its phase III trial testing Firdapse (amifampridine) for the treatment of patients with MuSK antibody-positive myasthenia gravis, which will begin in 2018. Catalyst is also developing Firdapse for Lambert-Eaton myasthenic syndrome (LEMS), for which it received a refuse-to-file letter last year.