Efficacy and safety of asenapine in a placebo- and haloperidol-controlled trial in patients with acute exacerbation of schizophrenia

Abstract

Asenapine is approved by the Food and Drugs Administration in adults for acute treatment of schizophrenia or of manic or mixed episodes associated with bipolar I disorder with or without psychotic features. In a double-blind 6-week trial, 458 patients with acute schizophrenia were randomly assigned to fixed-dose treatment with asenapine at 5 mg twice daily (BID), asenapine at 10 mg BID, placebo, or haloperidol at 4 mg BID (to verify assay sensitivity). With last observations carried forward (LOCF), mean Positive and Negative Syndrome Scale total score reductions from baseline to endpoint were significantly greater with asenapine at 5 mg BID (-16.2) and haloperidol (-15.4) than placebo (-10.7; both P < 0.05); using mixed model for repeated measures (MMRM), changes at day 42 were significantly greater with asenapine at 5 and 10 mg BID (-21.3 and -19.4, respectively) and haloperidol (-20.0) than placebo (-14.6; all P < 0.05). On the Positive and Negative Syndrome Scale positive subscale, all treatments were superior to placebo with LOCF and MMRM; asenapine at 5 mg BID was superior to placebo on the negative subscale with MMRM and on the general psychopathology subscale with LOCF and MMRM. Treatment-related adverse events (AEs) occurred in 44% and 52%, 57%, and 41% of the asenapine at 5 and 10 mg BID, haloperidol, and placebo groups, respectively. Extrapyramidal symptoms reported as AEs occurred in 15% and 18%, 34%, and 10% of the asenapine at 5 and 10 mg BID, haloperidol, and placebo groups, respectively. Across all groups, no more than 5% of patients had clinically significant weight change. Post hoc analyses indicated that efficacy was similar with asenapine and haloperidol; greater contrasts were seen in AEs, especially extrapyramidal symptoms.