Placebo-controlled evaluation of four novel compounds for the treatment of schizophrenia and schizoaffective disorder.

Objective: Four studies using identical protocols evaluated the safety and efficacy of four novel, evidence-based targets for antipsychotic agents: a neurokinin (NK(3)) antagonist (SR142801), a serotonin 2A/2C (5-HT(2A/2C)) antagonist (SR46349B), a central cannabinoid (CB(1)) antagonist (SR141716), and a neurotensin (NTS(1)) antagonist (SR48692).

Method: Adults with schizophrenia or schizoaffective disorder (N=481) were randomly assigned in a 3:1:1 ratio to receive fixed doses of investigational drug, placebo, or haloperidol for 6 weeks. Primary efficacy variables included changes from baseline in total score on the Positive and Negative Syndrome Scale, severity of illness score on the Clinical Global Impression (CGI), and total score and psychosis cluster score on the Brief Psychiatric Rating Scale (BPRS).