GlobeNewswire Inc | Jul 31, 2020 11:10AM EDT

July 31, 2020

CORAL GABLES, Fla., July 31, 2020 (GLOBE NEWSWIRE) -- Catalyst Pharmaceuticals, Inc. (Catalyst) (Nasdaq: CPRX), today reported that the Magistrate Judge considering Catalyst's lawsuit against the FDA has filed a Report and Recommendation in which she recommends to the District Judge handling the case that she grant the FDA's and Jacobus' motions for summary judgement and deny Catalyst's motion for summary judgement. Catalyst is currently reviewing the Magistrate Judge's decision, which it believes to be incorrect as a matter of law, and intends to pursue the case further with the District Judge. The decision on whether to grant or deny Catalyst's motion for summary judgement remains with the District Judge handling the case.

Patrick J. McEnany, the Company's Chairman and CEO, stated: "We are obviously very disappointed with the Magistrate Judge's recommendation, which we believe iscontrary to the plainlanguage of the Orphan Drug Act. If this recommendation is correct on the law, it means that the FDA can effectively eliminate the benefits of exclusivity under the Orphan Drug Act, which we believe will chill the incentive for drug companies like Catalyst to spend the millions of dollars necessary to develop an orphan drug."

Mr. McEnany continued: "This recommendation does not alter the fact that Jacobus Pharmaceuticals is not permitted under applicable law to market its amifampridine product to adult LEMS patients in the United States, and Catalyst intends to continue to aggressively take all steps necessary to protect Firdapses exclusivity under the Orphan Drug Act."

About Catalyst Pharmaceuticals

Catalyst Pharmaceuticals is a commercial-stage 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). Catalyst's new drug application for Firdapse (amifampridine) 10 mg tablets for the treatment of adults with LEMS was approved in November 2018 by theU.S. Food & Drug Administration("FDA"), and Firdapse is now commercially available inthe United States. Prior to its approval, Firdapse for LEMS had received breakthrough therapy designation and orphan drug designation from theFDA.

Forward-Looking Statements

This press release contains forward-looking statements. Forward-looking statements involve known and unknown risks and uncertainties, which may cause Catalyst's actual results in future periods to differ materially from forecasted results. A number of factors, including (i) whether Catalyst will successfully convince the District Judge to grant Catalyst's motion for summary judgment in light of the recommendation of the Magistrate Judge, (ii) whether Catalyst can continue to successfully market its product despite the lower price charged by Jacobus for its amifampridine drug, and (iii) those factors described in Catalyst's Annual Report on Form 10-K for the fiscal year 2019 and Catalyst's other filings with theU.S. Securities and Exchange Commission(SEC), could adversely affect Catalyst. Copies of Catalyst's filings with theSECare available from theSEC, may be found on Catalyst's website, or may be obtained upon request from Catalyst. Catalyst does not undertake any obligation to update the information contained herein, which speaks only as of this date.

Investor ContactBrian KorbSolebury Trout (646) 378-2923bkorb@troutgroup.com

Company ContactPatrick J. McEnanyCatalyst PharmaceuticalsChief Executive Officer(305) 420-3200pmcenany@catalystpharma.com

Media ContactDavid SchullRusso Partners(212) 845-4271david.schull@russopartnersllc.com