Catalyst Pharmaceuticals Reports Record Third Quarter 2022 Financial Results and Provides a Corporate Update Achieved Record Q3 2022 FIRDAPSE Net Revenue of $57.2 Million, a 59.3% YoY Increase Company Increases Full Year

Catalyst Pharmaceuticals Reports Record Third Quarter 2022 Financial Results and Provides a Corporate Update

Achieved Record Q3 2022 FIRDAPSE Net Revenue of $57.2 Million, a 59.3% YoY

Company Increases Full Year 2022 Total Revenue Guidance to $205-210 Million

Q3 2022 GAAP Net Income of $22.7 Million ($0.22 per basic and $0.20 per diluted share), which Includes a One Time Charge of $4.1

Million Related to the Acquisition of Ruzurgi

Investments Increased in Q3 2022 by $35.3 Million to $256.1 Million

Non-GAAP Net Income for

Q3 2022 of $28.6 Million ($0.28 per basic share and $0.26 per diluted share)

Company to Host a Conference Call and Webcast on

November 10, 2022, at 8:30 AM ET

CORAL GABLES, Fla. November 9, 2022 - Catalyst Pharmaceuticals,

Inc. ( Catalyst ) (Nasdaq: CPRX), a commercial-stage biopharmaceutical company focused on in-licensing, developing, and commercializing novel medicines for patients living with rare diseases,

today reported financial results and provided a corporate update for the third quarter of 2022.

Catalyst delivered another solid quarter driven by

record net revenues that exceeded expectations, marking this as another strong quarter of sequential growth of our FIRDAPSE brand. These results reflect our exceptional commercial execution

and continued commitment to the patient community that we serve, said Patrick J. McEnany, Chairman and CEO of Catalyst. Coupled with sustained organic growth, several significant milestones were achieved during the quarter that further

enhance the commercial runway and long-term growth potential for FIRDAPSE . The extraordinary execution across all segments of our business underscores our core competencies and adds further

confidence that we are on the right path to achieving our long-term goals. With robust year-to-date performance and continued momentum going into the fourth quarter, we

are raising our 2022 full year total revenue guidance to $205-210 million.

During the quarter, our priorities continued to be focused on commercial execution, preparing for the launch of our thoracic oncology programs to reach small-cell lung cancer patients with LEMS and diversifying our product portfolio with the

acquisition of innovative therapies that address unmet medical needs in rare diseases. Moving ahead, we are well positioned to continue to drive organic growth as we look to strengthen our business with strategic opportunities that translate into

added long-term value creation for all of our stakeholders.

RECENT BUSINESS HIGHLIGHTS

Third Quarter 2022 Financial Results

Revenue: Product revenue, net in the third quarter of 2022, was $57.2 million, compared to $35.9 million for the third quarter of 2021,

representing an increase of 59.3% year-over-year. Total revenue for the third quarter of 2022 was $57.2 million, compared to $36.0 million for the third quarter of 2021, representing an increase of 59.2% year-over-year.

Research and development expenses: Research and development expenses in the third quarter of 2022 were $8.3 million, compared to

$4.5 million in the third quarter of 2021. In connection with the Q3-22 Ruzurgi acquisition, a

one-time expense of $4.1 million related to the write-off of acquired inventory was included in R&D.

Selling, general, and administrative expenses: Selling, general, and administrative expenses for the

third quarter of 2022 were $14.2 million, compared to $12.2 million in the third quarter of 2021.

Operating income: Operating income for

the third quarter of 2022 was $25.1 million, compared to $14.0 million in the third quarter of 2021, representing an increase of 79.2% year-over-year.

GAAP net income: GAAP net income for the third quarter of 2022 was $22.7 million ($0.22 per basic and $0.20 per diluted share), compared to

$10.3 million ($0.10 per basic and diluted share) for the third quarter of 2021.

Non-GAAP1 net income for the third quarter of

2022 was $28.6 million ($0.28 per basic and $0.26 per diluted share), which excludes from GAAP net income of $22.7 million (i) stock-based compensation expense of $2.1 million, (ii) depreciation of $35 thousand,

(iii) amortization of $518 thousand, and (iv) the provision for income taxes of $3.3 million. This compares to Non-GAAP1 net income for

the third quarter of 2021 of $15.6 million ($0.15 per basic and $0.14 per diluted share), which excludes from GAAP net income of $10.3 million (i) stock-based compensation of $1.5 million, (ii) depreciation of

$31 thousand, and (iii) the provision for income taxes of $3.7 million.

Cash and investments: Cash and investments were

$256.1 million as of September 30, 2022.

Share repurchase program: The Company implemented a share repurchase program in March 2021. As

of September 30, 2022, the Company had repurchased approximately 3.2 million shares of Catalyst common stock in the open market, at an average price of $5.92 per share, for a total purchase price of approximately $19.0 million. As of

now the Company has suspended share repurchases to conserve cash for business development activities.

More detailed financial information and analysis

regarding the Company s financial position at September 30, 2022, and its results of operations for the three and nine months ended on that date can be found in the Company s Quarterly Report on Form

10-Q for the quarter ended September 30, 2022, which was filed with the U.S. Securities and Exchange Commission ( SEC ) on November 9, 2022.

2022 Financial Guidance: The Company has increased its forecast for the full year 2022 total revenues to be in the range of between

$205 million and $210 million, representing a 46% - 49% increase in total revenues compared to 2021, with cash operating expenses for the full year 2022 expected to be in the range of $65 million to $70 million and non-GAAP net income expected to be in the range of $100-105 million. Key guidance assumptions included in these forecasts reflect, among other risks, continued recovery

in healthcare activity throughout 2022 as it relates to the current COVID-19 environment.

The non-GAAP financial measure in this press release excludes from the calculation of net income (i) the expense associated with non-cash,

stock-based compensation, (ii) non-cash depreciation and amortization expense, and (iii) the provision for income taxes. Non-GAAP income per share is calculated by dividing non-GAAP income by the weighted average common shares outstanding.

Conference Call & Webcast Details

The Company will host a conference call and webcast on Thursday, November 10, 2022, at 8:30 AM ET to discuss the financial results and provide a business

US/Canada Dial-in Number: (866) 682-6100

International Dial-in Number: (862) 298-0702

A webcast and accompanying materials will be accessible under the investor section on the Company s website at www.catalystpharma.com. A webcast

replay will be available on the Catalyst website for 30 days following the date of the event.

About Catalyst Pharmaceuticals

Catalyst Pharmaceuticals is a commercial-stage biopharmaceutical company focused on in-licensing, developing, and

commercializing novel medicines for patients living with rare diseases. With exceptional patient focus, Catalyst is committed to developing a robust pipeline of cutting-edge,

best-in-class medicines for rare diseases. Catalyst s New Drug Application for

FIRDAPSE (amifampridine) Tablets 10 mg for the treatment of adults with Lambert-Eaton myasthenic syndrome ( LEMS ) was approved in 2018 by the U.S. Food & Drug

Administration ( FDA ) and FIRDAPSE is commercially available in the United States as a treatment for adults and children ages six to seventeen with LEMS.

Further, Canada s national healthcare regulatory agency, Health Canada, has approved the use of FIRDAPSE for the treatment of adult patients in Canada with

For additional information about the Company, please visit www.catalystpharma.com.

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) the effect of the COVID-19 pandemic on Catalyst s business and results of operations, (ii) Catalyst s ability to locate and acquire new product candidates through acquisition or in-licensing, (iii) Catalyst s ability to sell products acquired that are already approved and to successfully develop any new product candidates acquired or

in-licensed, (iv) whether Catalyst s total revenue, cash operating expense, and non-GAAP net income forecasts for 2022 will prove to be accurate,

(v) whether Catalyst s patents listed in the Orange Book will be sufficient to eliminate generic competition for FIRDAPSE after our orphan drug exclusivity for FIRDAPSE for LEMS expires in late November 2025, (vi) whether legislative changes currently being considered by Congress

that are intended to reduce the cost of prescription drug products will adversely affect Catalyst, and

(vii) those factors described in Catalyst s Annual Report on Form 10-K for the 2021 fiscal year and Catalyst s other filings with the 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.

Source: Catalyst Pharmaceuticals, Inc.

Contact information:

Catalyst Pharmaceuticals, Inc.

CATALYST PHARMACEUTICALS, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited)

(in thousands, except share data)

CATALYST PHARMACEUTICALS, INC.

RECONCILIATION OF NON-GAAP METRICS (unaudited)

(in thousands, except share data)

CATALYST PHARMACEUTICALS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS