Catalyst Pharmaceuticals Announces Third Quarter 2015 Financial Results and Provides Corporate Update Company to host quarterly conference call at 8:30am ET tomorrow

Catalyst Pharmaceuticals Announces Third Quarter 2015 Financial Results and Provides Corporate Update

CORAL GABLES, Fla., Nov 9, 2015 (GLOBE

NEWSWIRE) Catalyst Pharmaceuticals, Inc. (Nasdaq:CPRX), a biopharmaceutical company focused on developing and commercializing innovative therapies for people with rare debilitating diseases, today reported financial results for the third

quarter and nine months ended September 30, 2015.

The third quarter was a very productive period for the Catalyst team, with the initiation of

the rolling submission of our New Drug Application for the use of Firdapse in the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS) , said Patrick J. McEnany, Chairman and Chief

Executive Officer of Catalyst. We expect to complete the submission this quarter and at that time will be requesting a priority review.

Mr. McEnany added, We continue to advance our preparations for the planned commercial launch of Firdapse to treat LEMS, and we remain focused on

additional development efforts with Firdapse as a potential therapy for other neuromuscular diseases that represent unmet medical needs.

Upcoming 2015 Milestones:

For the quarter ended September 30, 2015, Catalyst reported a GAAP net loss of $4,449,038, or 5 cents per basic and diluted share, compared to a GAAP net

loss of $5,009,892, or 7 cents per basic and diluted share, for the same period in 2014. Excluding a non-cash gain of $521,731 attributable to the change in fair value of liability-classified warrants, Non-GAAP1 net loss was $4,970,769 or 6 cents per basic and diluted share for the third quarter of 2015. In comparison, Non-GAAP1 net loss for the third

quarter of 2014 was $4,103,105, or 6 cents per basic and diluted share, which excludes non-cash expense of $906,787 attributable to the change in fair value of liability-classified warrants.

For the nine months ended September 30, 2015, Catalyst reported a GAAP net loss of $14,417,800, or 18 cents per basic and diluted share, compared to a

GAAP net loss of $12,019,031, or 19 cents per basic and diluted share, for the same period in 2014. Excluding non-cash expense of $324,591 attributable to the change in fair value of liability-classified warrants, Non-GAAP1 net loss was $14,093,209 or 18 cents per basic and diluted share for the first nine months of 2015. In comparison, Non-GAAP1 net loss for the

first nine months of 2014 was $10,553,139, or 17 cents per basic and diluted share, which excludes non-cash expense of $1,465,892 attributable to the change in fair value of liability-classified warrants.

Research and development expenses for the third quarter of 2015 were $3,042,671 compared to $2,885,892 in the third quarter of 2014. For the nine months ended

September 30, 2015 research and development expenses were $7,969,731 compared to $7,733,533 in the same period in 2014. Research and development expenses increased when compared to the same period in 2014 as we increased activities related to

our NDA filing for Firdapse and ongoing studies and trials and decreased activities related to our completed Phase 3 trial for Firdapse. We expect that our research and development spend for the rest of the year will increase as we prepare for and

submit our NDA for Firdapse and as we increase activities in other ongoing studies and trials.

General and administrative expenses for the third quarter

of 2015 totaled $1,974,757 compared to $1,223,137 in the third quarter of 2014. For the nine months ended September 30, 2015 general and administrative expenses were $6,236,942 as compared to $2,874,034 in the same period in 2014.The increase

when compared to the same period in 2014 is primarily due to increases in pre-commercialization expenses and headcount, in preparation for the future commercialization of Firdapse.

As a development-stage biopharmaceutical company, Catalyst had no revenues in the third quarter of 2015 and 2014 or the first nine months of 2015 and 2014.

At September 30, 2015, Catalyst had cash and cash equivalents, certificates of deposit and short-term

investments of $63.0 million and no debt. This includes proceeds from our February 2015 offering in which we sold 11.5 million shares of our common stock, and raised net proceeds of approximately $34.9 million, and proceeds from stock option

and warrant exercises during 2015. We believe that these resources give us sufficient runway through anticipated approval and subsequent product launch of Firdapse, assuming approval in 2016.

More detailed financial information and analysis may be found in the Company s Quarterly Report on Form 10-Q, which was filed with the Securities and

Exchange Commission (SEC) on November 9, 2015.

Catalyst management will host an investment-community conference call and webcast at 8:30 a.m. EST on Tuesday, November 10, 2015 to discuss the

financial results and provide a corporate update. Investors who wish to participate in the conference call may do so by dialing (877) 407-8912 for domestic and Canadian callers or (201) 689-8059 for international callers. Those interested

in listening to the conference call live via the internet may do so by visiting the Investors page of the company s website at www.catalystpharma.com and clicking on the webcast link on the Investors home page. A webcast replay

will be available on the Catalyst website for 30 days following the call by visiting the Investor page of the company s website at www.catalystpharma.com.

About Catalyst Pharmaceuticals

Pharmaceuticals is a biopharmaceutical company focused on developing and commercializing innovative therapies for people with rare debilitating diseases, including Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes (CMS),

infantile spasms, and Tourette s Disorder. Catalyst s lead candidate, Firdapse for the treatment of LEMS, recently completed testing in a global, multi-center, pivotal Phase 3 trial resulting in positive top-line data. Firdapse for the

treatment of LEMS has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) and orphan drug designations for LEMS and CMS. Firdapse is the first and only European approved drug for symptomatic treatment

in adults with LEMS.

Catalyst is also developing CPP-115 to treat infantile spasms, epilepsy and other neurological conditions associated with reduced

GABAergic signaling, like post-traumatic stress disorder and Tourette s Disorder. 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).

Forward-Looking Statements

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 whether the receipt of breakthrough therapy designation for Firdapse will expedite the development and review of Firdapse by the FDA or the likelihood that the product will be found to be safe and

effective, what clinical trials and studies will be required before Catalyst can submit an NDA for Firdapse for the treatment of CMS and whether any such required clinical trials and studies will be successful, whether an NDA

for Firdapse will ever be accepted for filing by the FDA, the timing of any such NDA filing or acceptance, whether, if an NDA for Firdapse is accepted for filing, such NDA will be given a priority review by the FDA, whether Catalyst

will be the first company to receive approval for amifampridine (3,4-DAP), giving it 7-year marketing exclusivity for its product, whether CPP-115 will be determined to be safe for humans, whether CPP-115 will be determined to be

effective for the treatment of infantile spasm, post-traumatic stress disorder, Tourette s Disorder or any other indications, whether Catalyst can successfully design and complete a

bioequivalence study of its version of vigabatrin compared to Sabril that is acceptable to the FDA, whether any such bioequivalence study the design of which is acceptable to the FDA will be successful, whether any ANDA that Catalyst files for a

generic version of Sabril will be accepted for filing, whether any ANDA for Sabril accepted for filing by the FDA will be approved (and the timing of any such approval), whether any of Catalyst s product candidates will ever be approved for

commercialization or successfully commercialized, and those other factors described in Catalyst s Annual Report on Form 10-K for the fiscal year 2014 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.

CATALYST PHARMACEUTICALS, INC.

STATEMENTS OF OPERATIONS (unaudited)

CATALYST PHARMACEUTICALS, INC.

CONDENSED BALANCE SHEETS