CPRX Catalyst Pharmaceuticals Inc

Catalyst Pharmaceuticals, Inc. (NasdaqCM: CPRX) announced today that it has commenced an underwritten public offering of 8.0 million shares of its common stock. Catalyst also intends to grant the underwriters a 30-day option to purchase up to an additional 15% of the shares of common stock offered in the public offering on the same terms and conditions. The offering is subject to market conditions and there can be no assurance as to whether or when the offering may be completed, or the actual size or terms of the offering. All of the shares in the offering are being sold by Catalyst.

Piper Jaffray & Co. is acting as the lead bookrunner.

Catalyst plans to use the net proceeds from the offering: (i) to continue the commercialization activities for Firdapse (amifampridine phosphate); (ii) to fund business expansion activities in the U.S. and Japan; and (iii) for general corporate purposes, which may include the acquisition or in-license of additional product candidates or businesses.

The offering will be made pursuant to a preliminary prospectus supplement to Catalyst's prospectus to be filed under Catalyst's effective $150 million shelf registration statement (No. 333-219259). This press release shall not constitute an offer to sell or the solicitation of an offer to buy any securities nor will there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.

When available, copies of the preliminary prospectus supplement and the accompanying prospectus relating to these securities will be available on the Investor Relations section of the Company's website and on the SEC's website located at http://www.sec.gov. Copies may also be obtained by contacting Piper Jaffray & Co., Attention: Prospectus Department, 800 Nicollet Mall, J12S03, Minneapolis, MN 55402, or by telephone at 800-747-3924, or by e-mail at prospectus@pjc.com.

About Catalyst PharmaceuticalsCatalyst 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), anti-MuSK antibody positive myasthenia gravis (MuSK-MG), congenital myasthenic syndromes (CMS), and spinal muscular atrophy (SMA) Type 3. Catalyst's new drug application for Firdapse® (amifampridine) 10 mg tablets for the treatment of adults with LEMS was approved in November 2018 by the U.S. Food & Drug Administration ("FDA"), and Firdapse is now commercially available in the United States. Prior to its approval, Firdapse for LEMS had received breakthrough therapy designation and orphan drug designation from the FDA.

Firdapse is currently being evaluated in clinical trials for the treatment of MuSK-MG, CMS, and SMA Type 3 and has received Orphan Drug Designation from the FDA for myasthenia gravis and CMS. Firdapse (amifampridine) 10 mg tablets is the first and only approved drug in Europe for the symptomatic treatment in adults with LEMS.

Forward-Looking StatementsThis 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 and may include, without limitation, risks related to market conditions and other conditions related to the proposed offering. A number of factors, including those factors described in Catalyst's Annual Report on Form 10-K for the fiscal year 2018 and its other filings with the U.S. Securities and Exchange Commission (SEC), could adversely affect Catalyst. Copies of Catalyst's filings with the SEC are available from the SEC, 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 Contact
Brian Korb
Solebury Trout
(646) 378-2923
bkorb@troutgroup.com

Company Contact
Patrick J. McEnany
Catalyst Pharmaceuticals
Chief Executive Officer
(305) 420-3200
pmcenany@catalystpharma.com

Media Contacts
David Schull
Russo Partners
(212) 845-4271
david.schull@russopartnersllc.com