Asenapine: Efficacy and safety of 5 and 10mg bid in a 3-week, randomized, double-blind, placebo-controlled trial in adults with a manic or mixed episode associated with bipolar I disorder.

BACKGROUND: Asenapine is an atypical antipsychotic for acute treatment of manic or mixed episodes associated with bipolar I disorder in adults. The recommended asenapine starting dose is 10mg bid with the option to reduce the dose to 5mg bid if needed due to adverse effects/tolerability.

METHODS: Phase IIIb, international, double-blind, fixed-dose, parallel-group, 3-week placebo-controlled trial of asenapine 5 and 10mg bid in adults with an acute bipolar I disorder manic or mixed episode. Primary outcome was difference in asenapine versus placebo in mean change from baseline to day 21 in the Young-Mania Rating Scale (YMRS) total score. Others included difference in asenapine versus placebo in the Clinical Global Impression Scale for Bipolar Severity (CGI-BP-S) and rate of YMRS responders.

RESULTS: Both asenapine doses were statistically superior to placebo in mean change from baseline to day 21 in YMRS total score (-10.9, -14.4, and -14.9 for placebo, asenapine 5mg bid, 10mg bid, respectively). Both asenapine doses had statistically superior improvement in mean change in CGI-BP-S score at day 21. Neither asenapine dose had significantly more YMRS responders at day 21 than placebo.

LIMITATIONS: Results may not be generalizable to the entire population with bipolar I disorder owing to strict inclusion criteria.

CONCLUSIONS: This study evaluated, by a fixed-dose design, the efficacy and safety of asenapine versus placebo in patients with bipolar I disorder. Both asenapine 5 and 10mg bid were efficacious in treating mania associated with bipolar I disorder and were generally well tolerated.