–PDUFA Date Set for November 28, 2018

CORAL GABLES, FL, USA I May 29, 2018 I Catalyst Pharmaceuticals, Inc. (Catalyst) (Nasdaq:CPRX), a biopharmaceutical company focused on developing and commercializing innovative therapies for people with rare debilitating, chronic neuromuscular and neurological diseases, announced today that its New Drug Application (NDA) for Firdapse® for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) has been accepted for a Priority Review by the U.S. Food and Drug Administration (FDA).

Priority Review is granted by the FDA to drugs with the potential to address a serious condition and, if approved, would provide a significant improvement in safety or effectiveness of the treatment, prevention, or diagnosis of a serious condition. The FDA has set a Prescription Drug User Fee Act (PDUFA) action date of November 28, 2018. The submission is supported by positive results from two Phase 3 studies.

“We are delighted to have received Priority Review status for Firdapse for the treatment of LEMS and look forward to continuing to work closely with the FDA during the review process,” said Patrick J. McEnany, Chairman and CEO of Catalyst. “Together with the previous grant of Breakthrough Therapy Designation, the Priority Review underscores the robust potential of Firdapse and the need for a safe and effective FDA-approved treatment for LEMS.”

About Catalyst Pharmaceuticals

Catalyst Pharmaceuticals is a biopharmaceutical company focused on developing and commercializing innovative therapies for people with rare debilitating, chronic neuromuscular and neurological diseases, including Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes (CMS), MuSK antibody positive myasthenia gravis, spinal muscular atrophy (SMA) type 3, and infantile spasms. Firdapse® (amifampridine phosphate) has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) for the treatment of LEMS and Orphan Drug Designation for LEMS, CMS and myasthenia gravis. Firdapse is the first and only approved drug in Europe for symptomatic treatment in adults with LEMS.

Catalyst is also developing CPP-115 to treat refractory infantile spasms. CPP-115 has been granted U.S. Orphan Drug Designation for the treatment of infantile spasms by the FDA and has been granted E.U. Orphan Medicinal Product Designation for the treatment of West syndrome by the European Commission.  In addition, Catalyst is developing a generic version of Sabril® (vigabatrin).

SOURCE: Catalyst Pharmaceuticals