Efficacy and safety of quetiapine in adolescents with schizophrenia investigated in a 6-week, double-blind, placebo-controlled trial

Objective: The purpose of this study was to evaluate the efficacy and safety of acute quetiapine monotherapy in adolescents with schizophrenia. Methods: Patients ages 13-17 years with an American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) diagnosis of schizophrenia and a Positive and Negative Syndrome Scale (PANSS) total score ≥60 were randomized to 6 weeks of quetiapine (400 or 800mg/day) or placebo treatment. The primary efficacy measure was change in PANSS total score from baseline to day 42. Safety endpoints included adverse events and assessments of clinical chemistry values, suicidality, and extrapyramidal symptoms. Results: The intent-to-treat population included 220 patients. Least-squares mean change in PANSS total score from baseline to endpoint was -27.31 with quetiapine 400mg/day, -28.44 with quetiapine 800mg/day, and -19.15 with placebo (p=0.043 and 0.009 for quetiapine 400 and 800mg/day, respectively, vs. placebo; mixed-model, repeated-measures analysis). Several secondary efficacy outcomes, including Clinical Global Impressions-Improvement score, supported the primary outcome measure in demonstrating significantly greater improvement in quetiapine groups than in the placebo group. Mean changes in body weight at day 42 were 2.2kg and 1.8kg for quetiapine 400 and 800mg/day, respectively, and -0.4kg for placebo. Mean changes in certain clinical chemistry parameters, including total cholesterol and triglycerides, were numerically greater in the quetiapine groups than in the placebo group. Adverse events associated with quetiapine were mostly mild to moderate in intensity and were consistent with its known profile in adults with schizophrenia. Conclusions: In this 6-week study of adolescent patients, quetiapine at doses of 400 and 800mg/day provided significant improvements in symptoms associated with schizophrenia in adolescent patients, including the primary efficacy measure of PANSS total score change. Quetiapine was generally well tolerated with a profile broadly similar to that reported in adult and adolescent populations. Clinical trial registration information: Quetiapine Fumarate (SEROQUEL ^™) Compared to Placebo in the Treatment of Adolescent Patients With Schizophrenia (ANCHOR 112). Available at: http://www.clinicaltrials.gov/ ct2/show/NCT00090324?term=quetiapine+112&rank=1