Catalyst Pharmaceuticals Reports Strong Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update Achieved Record 2023 Total Revenues of $398.2 Million, an 85.9% Increase Compared to 2022 Achieved

Catalyst Pharmaceuticals Reports Strong Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update

Achieved Record 2023 Total Revenues of $398.2 Million, an 85.9% Increase Compared to 2022

Achieved Record Fourth Quarter 2023 Total Revenues of $110.6 Million, an 82.0% Increase Compared to Fourth Quarter 2022

Reported 2023 GAAP Net Income of $71.4 Million, $0.63 Per Share Diluted

Reported 2023 Non-GAAP Net Income of $223.2 Million, $1.96 Per Share Diluted

Bolstered Neuroscience Commercial Portfolio with the FDA Approval of AGAMREE

Commercial Launch of AGAMREE on Track for Q1 2024

Full Year 2024 Total Revenues Guidance of Between $455 Million and $475 Million

Conference Call and Webcast to be Held on February 29, 2024, at 8:30 AM ET

CORAL GABLES, Fla., February 28, 2024 - Catalyst Pharmaceuticals, Inc. ( Catalyst or Company ) (Nasdaq:

CPRX) today reported financial results for the fourth quarter and full year 2023 and provided a business update.

In 2023, Catalyst delivered

exceptional financial performance demonstrated by robust revenue growth, exceeding our full-year guidance. Our confidence for continued growth is strengthened by the outstanding execution of our strategic initiatives, expansion of our product

portfolio, and a growing commercial presence in the U.S. neuroscience market, stated Richard J. Daly, CEO of Catalyst. As we enter this year with compelling momentum, our commitment to execution and advancement of our initiatives, with a

concentration on orphan CNS and other strategic adjacencies, remains resolute. With an imminent U.S. commercial launch for AGAMREE , we are well poised to propel further growth. We eagerly

anticipate making this innovative therapy available to eligible Duchenne muscular dystrophy patients. Coupled with our accomplishments, substantial cash reserves, and prudent financial management, we aim to further fuel our growth through strategic

avenues that will deliver further value while upholding our steadfast commitment to serving our patient communities.

Financial Highlights

The non-GAAP financial measure included 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 expense, (iii) non-cash

amortization of intangible assets expense, (iv) acquired in-process research & development costs, and (v) the provision for income taxes. Non-GAAP net

income per share is calculated by dividing non-GAAP net income by the weighted average shares outstanding. See the Reconciliation of Non-GAAP Metrics table

Recent Business Highlights

Fourth Quarter 2023 and Full Year 2023 Financial Results

Total revenues: Total revenues in the fourth quarter of 2023 were $110.6 million, compared to $60.8 million for the fourth quarter

of 2022, representing an increase of approximately 82.0% quarter-over-quarter. For full-year 2023, total revenues were $398.2 million, compared to $214.2 million for the full-year 2022, representing an increase of approximately

Product revenue, net: Product revenue, net in the fourth quarter of 2023, was $109.1 million, compared to $60.7 million for

the fourth quarter of 2022, representing an increase of approximately 79.8% YoY. The full-year 2023 product revenue, net was $396.5 million, compared to $213.9 million for 2022, representing an increase of approximately 85.3% YoY.

Research and development expenses: In the fourth quarter of 2023, research and development expenses were $2.0 million, compared

to $4.1 million in the fourth quarter of 2022. Research and development expenses for the full-year 2023 were $93.2 million (including a one-time charge of in-process research and development expense related to the acquisition of the license for AGAMREE in the amount of $81.5 million), compared to $19.8 million for the full-year 2022.

Selling, general, and administrative expenses: Selling, general, and administrative expenses for the fourth quarter of 2023

were $42.0 million compared to $14.1 million in the fourth quarter of 2022. Selling, general, and administrative expenses for the full year 2023 were $133.7 million, compared to $57.1 million for 2022. Both

the QoQ and YoY increases were driven by incremental effort to support FYCOMPA and pre-launch investments in preparation for the acquisition of FYCOMPA in the first quarter of 2023 and the AGAMREE launch in

the first quarter of 2024.

Amortization of intangible Assets. Amortization of intangible assets was $9.1 million in the fourth quarter of

2023), compared to $0.6 million in the fourth quarter of 2022. Amortization of intangible assets was $32.6 million in full-year 2023, compared to $1.1 million in full year 2022. Amortization of intangible assets acquired in 2023

relate to the FYCOMPA rights acquired during the first quarter of 2023 and the milestone payment made to Santhera upon the approval of AGAMREE during the fourth quarter of 2023.

Operating income: Operating income for the fourth quarter of 2023 was $41.7 million, compared to $30.8 million in the

fourth quarter of 2022, representing an increase of approximately 35.4%. The full-year 2023 operating income was $86.8 million, compared to $101.8 million for the full year 2022, representing a decrease of approximately

14.8%, which is inclusive of the one-time AGAMREE related in-process R&D expense of $81.5 million in connection with the acquisition of the license.

GAAP net income: GAAP net income for the fourth quarter of 2023 was $34.8 million ($0.33 per basic and $0.31 per diluted share), compared to GAAP

Net Income of $25.5 million ($0.24 per basic and $0.22 per diluted share) for the fourth quarter of 2022. GAAP net income for full year 2023 was $71.4 million ($0.67 per basic and $0.63 per diluted share), compared to the full year 2022

GAAP net income of $83.1 million ($0.80 per basic and $0.75 per diluted share).

Non-GAAP net income:

Non-GAAP net income for the fourth quarter of 2023 was $60.1 million ($ 0.56 per basic and $0.53 per diluted share), compared to non-GAAP net income of

$35.5 million ($0.34 per basic and $0.31 per diluted share) for the fourth quarter of 2022. Non-GAAP net income for full year 2023 was $223.2 million ($2.10 per basic and $1.96 per diluted share),

compared to full year 2022 non-GAAP net income of $113.9 million ($1.10 per basic and $1.02 per diluted share).

Cash and cash equivalents: Cash and cash equivalents were $137.6 million as of December 31, 2023.

More detailed financial information and analysis of our financial condition and results of operations can be found in our Annual Report on Form 10-K for fiscal year 2023, which was filed with the U.S. Securities and Exchange Commission on February 28, 2024.

Product revenue, net: Bolstered by

continued growth of FIRDAPSE and additional net product revenue from AGAMREE, which we expect to launch during the first quarter of 2024, we anticipate achieving total revenues in 2024 within the range of $455 million and $475 million,

reflecting net product revenue of approximately $295 million to $310 million for FIRDAPSE, AGAMREE net product revenue of approximately $25 million to $30 million, and FYCOMPA net product revenue of approximately

$130 million to $135 million.

Product revenue for FYCOMPA in 2024 will be affected by differences in variable consideration (gross-to-net) compared to 2023, when revenues were booked under Eisai s cost arrangements with distributors and government authorities. Starting on January 1, 2024,

all such costs are tied to arrangements between the Company and those distributors and government agencies, which costs are likely to be higher than Eisai s costs, thereby increasing the gross-to-net deductions for FYCOMPA and correspondingly decreasing FYCOMPA net product revenue.

development expenses: Due to the expected launch of the AGAMREE long-term safety and quality of life study, we anticipate research and development expenses in 2024 to approximate the amount that was incurred in 2022.

Selling, general, and administrative expenses: We anticipate a significant increase in selling, general and administrative expenses in 2024 due to the

launch of AGAMREE and the accompanying support of three commercial products, compared to two in 2023.

Tax rate: We anticipate our effective tax

rate to increase slightly for 2024.

Conference Call & Webcast Details

The Company will host a conference call and webcast on February 29, 2024, at 8:30 AM ET to discuss the financial results and provide a business update.

A webcast 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 after the event.

Pharmaceuticals, Inc.

With exceptional patient focus, Catalyst is committed to developing and commercializing innovative first-in-class medicines that address rare and difficult to treat diseases. Catalyst s flagship U.S. commercial product is FIRDAPSE (amifampridine) Tablets 10 mg, approved for the treatment of Lambert-Eaton myasthenic syndrome ( LEMS ) for adults and for children ages six to seventeen. In January 2023,

Catalyst acquired the U.S. commercial rights to FYCOMPA (perampanel) CIII, a prescription medicine approved in people with epilepsy aged four and older alone or with other

medicines to treat partial-onset seizures with or without secondarily generalized seizures and with other medicines to treat primary generalized tonic-clonic seizures for people with epilepsy aged 12 and older.

Further, Canada s national healthcare regulatory agency, Health Canada, has approved the use of FIRDAPSE for the treatment of adult patients in Canada with LEMS. Finally, on July 18, 2023, Catalyst acquired an

exclusive license for North America for AGAMREE (vamorolone) oral suspension 40 mg/mL, a novel corticosteroid treatment for Duchenne Muscular Dystrophy. AGAMREE previously

received FDA Orphan Drug and Fast Track designations and was approved by the FDA for commercialization in the U.S. on October 26, 2023.

information about Catalyst Pharmaceuticals, Inc., visit the Company s website at www.catalystpharma.com. For Full Prescribing and Safety Information for FIRDAPSE ,

visit www.firdapse.com. For Full Prescribing Information, including Boxed WARNING for FYCOMPA , please visit www.fycompa.com. For Full Prescribing Information for

AGAMREE, please visit https://www.agamree.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) whether AGAMREE can be successfully launched and whether that launch will occur in the first quarter of 2024, (ii)

whether AGAMREE s commercialization will be successful and accretive to Catalyst, (iii) Catalyst s ability to continue to sell its current products, (iv) whether Catalyst will continue to be profitable and cash flow positive,

(v) whether Catalyst s total revenues and net product revenue forecasts for 2024 will prove to be accurate, (vi) whether Catalyst will complete more acquisitions of products, and the timing of such acquisition; and (vii) those

factors described in Catalyst s Annual Report on Form 10-K for the 2023 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:

Mary Coleman, Catalyst Pharmaceuticals,

David Schull, Russo Partners

CATALYST PHARMACEUTICALS, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

(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