POSITIVE PHASE II TRIAL RESULTS FOR VIGABATRIN IN THE TREATMENT OF COCAINE ADDICTION

- Study Demonstrates Statistically Significant Efficacy vs. Placebo

- Trial Conducted Under Direction of New York University School of Medicine

NEW YORK, NY – December 7, 2007 – Catalyst Pharmaceutical Partners, Inc. today reported positive results for the first large, controlled clinical trial of a drug called vigabatrin to treat cocaine addiction. The trial was directed and initiated by Jonathan Brodie, M.D., Ph.D., the Marvin Stern Professor of Psychiatry at the New York University School of Medicine.

“These positive results demonstrate that there is hope for the millions of individuals who suffer from the life threatening consequences of this terrible illness,” said Dr. Brodie. “It also demonstrates how a dedicated team of basic scientists and clinicians who persevere in a mission can produce important medical advances by taking an idea from the bench to the community.“

This trial is the third in a series of human trials conducted in Mexico, which successfully tested the safety and efficacy of vigabatrin to treat cocaine and/or methamphetamine addiction. All three human trials were conducted under the direction of Dr. Jonathan Brodie, and Dr. Emilia Figueroa, Director of the Clinica Integral de Tratamiento Contra las Adicciones, S.A. de C.V. The trial’s protocol was approved by NYU’s Institutional Review Board in May 2006 and the Federal Commission for Sanitary Risks Protection (Mexico) in September 2006 and is registered at www.clinicaltrials.gov with the identifier NCT00527683. Catalyst provided financial support through an unrestricted gift to NYU.

Over the past decade Drs. Dewey of Brookhaven National Laboratory, and Dr. Brodie of NYU and their colleagues have studied GVG in animals, and have published numerous articles showing that the treatment in animals blocks the rise in dopamine levels produced by cocaine, nicotine and many other addicting substances. Dopamine is a brain chemical associated with the pleasurable effects of addicting drugs. Achievement of abstinence for an extended period during treatment is the critical first step for cocaine addicted patients to potentially achieve abstinence for much longer time periods. The data confirm the positive results seen in two previous open-label trials conducted in 2003 and 2004 by the same investigators.

One hundred and three community-based, non-hospitalized cocaine addicted individuals participated in this investigator-initiated, randomized, double-blind, placebo-controlled trial conducted at a single site in Mexico City. All subjects had ready access to cocaine and were self-motivated to stop their use. The trial was designed to show whether vigabatrin treatment could significantly increase abstinence compared to placebo. Subjects were randomly assigned to either a placebo or vigabatrin and were treated for a period of nine weeks. Of the 103 participants in the trial, 50 were treated with vigabatrin and 53 received placebo. Twice-weekly urine screening tests were obtained from each subject in order to objectively evaluate each subjects’ cocaine use. The primary outcome measure of the trial was negative urine tests for cocaine for the last three weeks of the nine-week trial.

A total of 18 subjects fulfilled the criteria for the primary outcome measure. Of these, 14 (28%) were treated with vigabatrin versus four (7.6%) who were treated with placebo.

There were no serious adverse events reported in this trial.

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