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 Provides Update on FIRDAPSETM Progress

CORAL GABLES, Fla., June 27, 2013 (GLOBE NEWSWIRE) 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 provided an update on its progress with its lead investigational product, FIRDAPSETM.

Over the past six months, we have made great strides in our advancement of Firdapse for the treatment of Lambert-Eaton Myasthenic Syndrome (LEMS). We have recently achieved several important

milestones in our development plan, and we therefore feel that this is an appropriate time to report our progress to investors and other stakeholders, said Patrick J. McEnany, Chief Executive Officer of Catalyst Pharmaceutical Partners, Inc.

Firdapse Progress Report To Date:

In October 2012, Catalyst acquired the North American rights to Firdapse, a proprietary form of amifampridine phosphate (3-4 diaminopyridine or 3,4-DAP), from BioMarin Pharmaceutical Inc.

( BioMarin ). As part of that transaction, BioMarin made a $5 million strategic investment in Catalyst to help fund the development of Firdapse. Firdapse was approved in December 2009 by the European Medicines Agency for the treatment of

Lambert-Eaton Myasthenic Syndrome (LEMS), a rare and sometimes fatal autoimmune disease characterized by muscle weakness. Firdapse has been granted orphan drug designation by the U.S. Food & Drug Administration, (FDA) for the treatment of

LEMS, making the product eligible to obtain seven-year marketing exclusivity if Catalyst is the first pharmaceutical company to obtain approval of an NDA for its formulation of amifampridine.

Catalyst has recently completed the following activities in the development of Firdapse for LEMS:

Based on this progress and its patient enrollment projections, Catalyst continues to

Assuming positive results are obtained from the Phase III trial, Catalyst expects:

Lambert-Eaton Myasthenic Syndrome, LEMS, is a rare autoimmune disease that can be severely disabling, with the primary symptom of muscle weakness. The weakness is generally more marked in the proximal

muscles, particularly of the legs and trunk. Other problems include reduced reflexes, drooping of the eyelids, facial weakness and problems with swallowing. Patients often report dry mouth, impotence, constipation and feelings of light headedness on

standing. These problems can be life threatening when the weakness involves respiratory muscles. The muscle weakness in LEMS is caused by autoantibodies to voltage gated calcium channels, which cause a reduction in the amount of acetylcholine

released from nerve terminals. The prevalence of LEMS is estimated at approximately 3,000 patients in the United States and Canada. Approximately 50 percent of LEMS patients diagnosed have small cell lung cancer. Patients with LEMS typically present

with fatigue, muscle pain and stiffness. A diagnosis of LEMS is generally made on the basis of clinical symptoms, electromyographic and compound muscle action potential (CMAP) testing and where available, the presence of autoantibodies against

voltage gated calcium channels.

About Catalyst Pharmaceutical Partners

Catalyst Pharmaceutical Partners, Inc., is a specialty pharmaceutical company focused on the development and commercialization of prescription drugs

targeting rare (orphan) neuromuscular and neurological diseases, including Lambert-Eaton Myasthenic Syndrome (LEMS), infantile spasms, and Tourette s 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 s Syndrome, and movement disorders associated with the treatment of Parkinson s Disease.

Forward-Looking Statements

press release contains forward-looking statements. Forward-looking statements involve known and unknown risks and uncertainties, which may cause the Company s actual results in future periods to differ materially from forecasted results. A

number of factors, including the timing of adding additional sites to the Phase III trial, the timing of completion of the enrollment of all trial subjects who will participate in the Phase III trial, the timing of the receipt of the top-line

results from the double-blind portion of the Phase III trial, whether any of the Company s product candidates will ever be approved for commercialization, and those factors described in the Company s filings with the U.S. Securities and

Exchange Commission (SEC), could adversely affect the Company. Copies of the Company s filings with the SEC are available from the SEC, may be found on the Company s website or may be obtained upon request from the Company. The Company

does not undertake any obligation to update the information contained herein, which speaks only as of this date.