Adjuvant Treatment With a Glycine Uptake Inhibitor in Subjects With Chronic Schizophrenia (Study 172003)(COMPLETED)(P05695) (GIANT)
The purpose of this study is to determine whether Org 25935 is more effective
than placebo in improving negative symptoms in subjects with schizophrenia who
are concurrently treated with a stable dose of a second generation antipsychotic.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
|Official Title:||A Multi-center, Double-blind, Flexible-dose Efficacy Trial With Org 25935 Versus Placebo as add-on Therapy in Subjects With Predominant, Persistent Negative Symptoms of Schizophrenia Treated With a Stable Dose of a Second Generation Antipsychotic|
- Reduction of the total score (items 1-22) on the Scale for Assessment of Negative Symptoms (SANS) within twelve weeks treatment. [ Time Frame: 12 weeks treatment ] [ Designated as safety issue: No ]
- Reduction of composite scores on the Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia, Extrapyramidal Symptoms Rating Scale, and computerized cognitive battery within twelve weeks treatment. [ Time Frame: twelve weeks treatment ] [ Designated as safety issue: No ]
|Study Start Date:||April 2007|
|Study Completion Date:||October 2008|
|Primary Completion Date:||October 2008 (Final data collection date for primary outcome measure)|
Experimental: Arm 1
Org 25935 (8-16 mg per day)
Drug: Org 25935
After screening, eligible subjects will be maintained on a stable dose of
Second Generation Antipsychotic (SGA) and will be randomized to
double-blind add-on treatment, i.e., twice daily (morning and evening) oral
administration of 4-8 mg Org 25935. This phase will last 84 (81-87) days for all subjects.
Experimental: Arm 2
Org 25935 (24-32 mg per day)
Drug: Org 25935
After screening, eligible subjects will be maintained on a stable dose of Second Generation Antipsychotic (SGA) and will be randomized to double-blind add-on treatment, i.e., twice daily (morning and evening) oral administration of 12-16 mg Org 25935. This phase will last 84 (81-87) days for all subjects.
Placebo Comparator: Arm 3
The primary features of schizophrenia are characterized by positive (irrational
thoughts and/or behavior) and negative symptoms. Negative symptoms are the
gross absence of normal behavior and emotions, and usually include a general
lack of engagement, social withdrawal, and loss of goal-directed behavior.
Negative symptoms may strongly affect daytime activities and quality of life. The effects of currently available antipsychotics on negative symptoms are not satisfactory and leave much room for improvement. Org 25935 is an investigational drug that may help to correct the above characteristics of schizophrenia by facilitating the messenger function of an amino acid in the brain, called glutamate. Preliminary data suggest that lowered glutamate levels in schizophrenia are associated with a failure to activate relevant areas in the
forebrain and with prominent negative symptoms.