Catalyst Pharmaceutical Updates on its Development Activities for Firdapse

Catalyst Pharmaceutical Updates on its Development Activities for Firdapse

CORAL GABLES, FL, October 29, 2013 Catalyst Pharmaceutical Partners, Inc. (Nasdaq: CPRX), a specialty pharmaceutical company focused on

developing safe and effective approved medicines targeting orphan neuromuscular and neurological diseases, provided an update on the status of its development activities for its lead product candidate, Firdapse , which is being evaluated in a

pivotal Phase 3 clinical trial for the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS).

The Phase 3 trial is designed as a randomized,

double-blind, placebo-controlled discontinuation study followed by an open-label extension period in approximately 36-patients across 19 sites in the United States and Europe. Catalyst also expects to add approximately six sites in the United States

(US), Canada, South America and Europe in the near future. Firdapse for the treatment of LEMS has recently been granted Breakthrough Therapy designation by the U.S. Food & Drug Administration (FDA).

Catalyst expects that it will report top-line results from the double-blind portion of this Phase 3 trial during the second quarter of 2014 and, if the trial

results are successful, Catalyst expects to submit a new drug application (NDA) with the FDA in the first half of 2015. Further, as previously reported, an interim safety analysis was recently performed by the independent Data Safety Monitoring

Committee that is part of the routine oversight of the Phase 3 trial. Following this meeting, the Committee recommended that Catalyst continue the trial as planned. This recommendation is based on the Committee s review of unblinded safety and

clinical data available from the on-going trial.

Patrick McEnany, Catalyst s Chairman and CEO, commented, Catalyst is dedicated to advancing

important life-altering therapies targeting rare neuromuscular diseases. We are committed to combatting LEMS as our first orphan disease priority, followed by infantile spasms and Tourette Syndrome. If we are successful in bringing Firdapse to

market, it will be the first ever FDA approved product, demonstrating safety and efficacy for the treatment of LEMS. We expect that Catalyst and Firdapse will provide LEMS patients and their physicians with an alternative therapeutic option

and easier access to on-going support.

The Company also commented on the following matters relating to the development of Firdapse :

Catalyst also reported that it has seen press releases disseminated by several law firms announcing that they have filed class action lawsuits against the

company and one or more of its officers and directors alleging violations of federal securities laws. Catalyst believes such suits to be without merit and such suits will be vigorously defended.

About Catalyst Pharmaceutical Partners

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 3 trial and recently received

Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA). In 2012, Catalyst licensed Firdapse from BioMarin and Catalyst assumed management of the Phase 3 pivotal trial, initiated by BioMarin.

Firdapse is the first and only European approved drug for symptomatic treatment in adults with LEMS.

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 and Tourette Syndrome.

CPP-115 has been granted US orphan drug designation for the treatment of infantile spasms by the FDA and has been granted EU orphan medicinal product designation for the treatment of West Syndrome by the European Commission.

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 the timing of completion of Catalyst s currently ongoing Phase 3 trial of Firdapse , whether the Phase 3 trial

will be successful, 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, whether

an NDA for Firdapse will ever be accepted for filing by the FDA, the timing of any such NDA filing or acceptance, whether Catalyst will be the first company to receive an approval for 3,4-DAP, giving it 7-year marketing exclusivity for its

product, 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 2012 and 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.