Asenapine in the treatment of acute mania in bipolar I disorder: a randomized, double-blind, placebo-controlled trial.

Background: Asenapine is indicated in adults for acute treatment of manic or mixed episodes associated with bipolar I disorder with or without psychotic features. This randomized, double-blind, placebo-controlled trial assessed the efficacy, safety, and tolerability of asenapine in bipolar I disorder.

Methods: Adults experiencing manic or mixed episodes were randomized to 3 weeks of flexible-dose treatment with sublingual asenapine (day 1: 10mg BID, 5 or 10mg BID thereafter; n=185), placebo (n=98), or oral olanzapine (day 1: 15 mg QD, 5-20mg QD thereafter; n=205). Primary efficacy, YMRS total score change from baseline to day 21, was assessed using ANCOVA with last observation carried forward.

Results: Mean daily doses were 18.4 mg asenapine and 15.9mg olanzapine. Least squares mean changes in YMRS total score on day 21 were significantly greater with asenapine than placebo (-11.5 vs -7.8; P<0.007), with advantage seen as early as day 2 (-3.2 vs -1.7; P=0.022). Changes with olanzapine on days 2 and 21 also exceeded placebo (both P<0.0001). YMRS response and remission rates with olanzapine, but not asenapine, exceeded those of placebo. Incidence of EPS-related adverse events was 10.3%, 3.1%, and 6.8% with asenapine, placebo, and olanzapine, respectively; incidence of clinically significant weight gain (7.2%; 1.2%; 19.0%). Mean weight change (baseline to endpoint) was 0.9, 0.1, and 2.6 kg with asenapine, placebo, and olanzapine, respectively.

Conclusions: As this short-term study was designed for comparisons with placebo, any comparisons between asenapine and olanzapine should be interpreted cautiously. Conclusions: Asenapine was superior to placebo in reducing YMRS total score and was well tolerated.