For Further Information Contact: Patrick J. McEnany Melody Carey Catalyst Pharmaceutical Partners Rx Communications Group Chief Executive Officer Co-President (305) 529-2522 (917) 322-2

Catalyst Pharmaceutical Partners Announces Second Quarter 2013 Financial Results

CORAL GABLES, FL, August 15, 2013 Catalyst Pharmaceutical Partners, Inc. (Nasdaq: CPRX), a specialty pharmaceutical company focused on

the development and commercialization of novel prescription drugs targeting rare (orphan) neuromuscular and neurological diseases, today announced financial results for the second quarter and six months period ended June 30, 2013.

We are pleased with the progress that we have made toward initiating new clinical trial sites and enrollment of patients in our Phase III clinical

trial for Firdapse to treat patients with Lambert-Eaton Myasthenic Syndrome (LEMS). Since assuming the management of this trial from BioMarin, we have added 8 new trial sites, and we expect to add an additional 8 trial sites by the end of

September. We continue to expect that we will report top-line data from this trial in the second quarter of 2014, said Patrick J. McEnany, Catalyst s Chairman and Chief Executive Officer. The Catalyst team is focused on all

activities necessary for a successful registration trial, and we have also begun pre-commercialization activities for Firdapse .

For the quarter ended June 30, 2013, Catalyst reported a GAAP net loss of $3,143,590, or $0.08 per basic and diluted share,

compared to a GAAP net loss of $289,080, or $0.01 per basic and diluted share, for the same period in 2012. Excluding non-cash expense of $498,587 attributable to the change in fair value of liability-classified warrants, Non-GAAP1 net loss was $2,645,003 or $0.06 per share for the second quarter of

2013. In comparison, Non-GAAP1 net loss for the second

quarter of 2012 was $1,065,999, or $0.04 per share, which excludes non-cash income of $776,919 attributable to the change in fair value of liability-classified warrants.

For the six months ended June 30, 2013, Catalyst reported a GAAP net loss of

$4,887,879, or $0.12 per basic and diluted share, compared to a GAAP net loss of $1,378,266, or $0.05 per basic and diluted share, for the same period in 2012. Excluding non-cash expense of $543,913 attributable to the change in fair value of

liability-classified warrants, Non-GAAP1 net loss was

$4,343,966 or $0.10 per share for the six months ended June 30, 2013. In comparison, Non-GAAP1 net loss for the six months ended June 30, 2012 was $2,429,392, or $0.09 per share, which excludes non-cash income of $1,051,126 attributable to the change in fair value of liability-classified

Research and development expenses for the second quarter of 2013 were $2,132,038, compared to $532,741 in the second quarter of

2012. For the six months ended June 30, 2013, research and development expenses were $3,224,339, compared to $1,260,068 in the comparable period of 2012. Research and development expenses increased when compared to the same period in 2012 as

Catalyst expanded its activities associated with the currently ongoing phase III trial evaluating Firdapse for the treatment of LEMS. Catalyst expects that research and development expenses will increase during 2013 as a result of the ongoing

development projects for Firdapse .

General and administrative expenses for the second quarter of 2013 totaled $521,491, compared to

$534,623 in the second quarter of 2012. For the six months ended June 30, 2013, general and administrative expenses totaled $1,134,620, compared to $1,172,006 in the same period in 2012.

As a development-stage specialty pharmaceutical company, Catalyst had no revenues in either the second quarter of 2013 or the first six months of 2013.

At June 30, 2013, Catalyst had cash and cash equivalents, certificates of deposit and short-term investments of $11.4 million and no debt. Catalyst

believes that its existing cash and investments will be sufficient to meet its currently anticipated working capital requirements through the first quarter of 2014.

Upcoming Investor Conferences

Catalyst s CEO, Patrick J. McEnany and COO/CSO,

Dr. Steven Miller will present at the following investor conferences:

About Catalyst Pharmaceutical Partners

Catalyst Pharmaceutical Partners, Inc. is a

specialty pharmaceutical company focused on the development and commercialization of novel prescription drugs targeting rare (orphan) neuromuscular and neurological diseases, including Lambert-Eaton Myasthenic Syndrome (LEMS), infantile spasms, and

Tourette Syndrome. Catalyst s lead candidate, Firdapse for the treatment of LEMS, is currently undergoing testing in a global, multi-center, pivotal phase III trial. Catalyst is also developing a potentially safer and more potent

vigabatrin analog (designated CPP-115) to treat infantile spasms, and epilepsy, as well as other neurological conditions associated with reduced GABAergic signaling, like post-traumatic stress disorder, Tourette Syndrome, and movement disorders.

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 whether the Phase III trial evaluating Firdapse for the treatment of LEMS will be successful, whether the Phase III trial will be completed on the expected timeline,

whether Catalyst has sufficient resources to meet its currently anticipated working capital requirements through the first quarter of 2014, as well as those factors described in Catalyst s Annual Report on Form 10-K for the fiscal year 2012 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 PHARMACEUTICAL PARTNERS, INC.

(a development stage company)

CONDENSED STATEMENTS OF OPERATIONS (unaudited)

CATALYST PHARMACEUTICAL PARTNERS, INC.

(a development stage company)

CONDENSED BALANCE SHEETS