Catalyst Announces Top-Line Results In Proof-of-Concept Trial Of Vigabatrin

(RTTNews) - Catalyst Pharmaceuticals Inc. (CPRX) announced top-line results in an open-label, proof-of-concept trial of CPP-109 (vigabatrin) used to treat patients suffering from Tourette's Disorder or TD that were refractory to all other previous treatments. One of four patients demonstrated a very clear, clinically significant reduction in tics, and two others showed about a 25% reduction in tics, but without subjective clinical improvement.

The trial was designed to obtain preliminary data regarding clinical effect, dosage, and tolerability of vigabatrin in subjects at least 18 years of age with a DSM-IV-TR diagnosis of Tourette's Disorder, who exhibited unsatisfactory response to all prior treatments.

The 8-week clinical trial was designed as an open label trial to evaluate the potential effect of GABA-aminotransferase inhibition as a mechanism for reducing tics in patients with treatment-refractory Tourette's Disorder. Vigabatrin was used as a "research surrogate" to demonstrate the utility of GABA-aminotransferase (GABA-AT) blockade, with the expectation that upon successfully demonstrating the utility of this mechanism, further development activities would focus on the potentially safer, more potent GABA-AT inhibitor, CPP-115.

During the trial, each subject's Yale Global Tic Severity Score (YGTSS), Clinical Global impression for Tics (CGI-Tics: the doctor's assessment of motor and vocal tic symptom severity), and Global Assessment of Functioning score (GAF: an assessment of psychological, social, and occupational impairment) were collected at baseline (prior to treatment) and at various points during treatment.

There was a statistically significant change between baseline and week six of treatment (the last point at which subjects were on the maximum dose) for all the tic assessments, and a clinically significant change for all of the assessments in one of the four subjects.

This subject was featured as a treatment success on Mount Sinai Hospital's Patient Stories for the Tics and Tourette's Program web page. Two other subjects also showed a measurable change in tic assessments, but without subjective improvement. Visual field testing was conducted before and after treatment, and no significant alterations to vision were detected. One of the subjects has remained on vigabatrin for two years, and periodic visual field testing has shown no alteration in the subject's field of vision.