Quetiapine immediate release (quetiapine IR) improves PANSS total, positive, negative and general psychopathology scores in schizophrenia. This study (D1444C00132) evaluated the efficacy of once-daily extended release quetiapine fumarate (quetiapine XR) in patients with acute schizophrenia.

This was a 6-week, double-blind, randomised study (n=588) comparing quetiapine XR (400, 600 or 800 mg/day) and quetiapine IR (400 mg/day) with placebo. Efficacy was assessed using ANCOVA analyses of the change from baseline to study endpoint (Day 42) for: PANSS total score; positive, negative and general psychopathology subscale scores; and aggression and depression cluster scores (modified ITT population, LOCF). Changes in individual PANSS item scores were assessed post hoc.

At Day 42, there were statistically significant reductions (ie two-sided p-value <0.05) versus placebo with all doses of quetiapine XR for the change in PANSS total, positive, general psychopathology and aggression cluster scores. Changes in negative and depression cluster scores were statistically significant versus placebo for quetiapine XR 600 mg/day and 800 mg/day. There was statistically significant separation from placebo with quetiapine XR 600 mg/day and 800 mg/day for the change in 6/7 PANSS positive items, 5/7 negative items, and 12/16 general psychopathology items. For those items with no statistically significant separation from placebo, baseline scores were generally low.

Once-daily quetiapine XR is effective across a broad range of symptoms in acute schizophrenia, including positive and negative symptoms, as well as symptoms of general psychopathology, aggression and depression.