Review of the safety, efficacy, and side effect profile of asenapine in the treatment of bipolar 1 disorder

OBJECTIVE Asenapine is approved for acute manic and mixed states in bipolar disorder. The objective is to review the efficacy of asenapine in bipolar disorder, with a particular focus on acceptability and adherence to treatment. METHODS FIVE CLINICAL TRIALS WERE CONDUCTED IN BIPOLAR DISORDER MANIC OR MIXED STATES: two 3-week trials (n = 976) comparing asenapine to placebo, a 9-week extension (n = 504), and a 40-week extension (n = 107). One trial was conducted comparing asenapine to placebo (n = 326) as adjunctive therapy for subjects with an incomplete response to lithium or valproate. All trials were conducted in the USA and internationally. RESULTS Asenapine was found to be efficacious for manic and mixed states in bipolar disorder compared with placebo control, and compares equally well to olanzapine on efficacy measures after 3 weeks of treatment. Asenapine was not found to be efficacious for depression symptoms. Common asenapine side effects in the 40-week extension trial were sedation, insomnia, and dizziness, and 31% reported clinically significant weight gain, compared with 55% reporting clinically significant weight gain with olanzapine. Additionally, 18% had clinically significant changes in fasting blood glucose levels compared to 22% of those on olanzapine. In terms of patient acceptability, one concern may be sublingual administration requiring no liquids or food for 10 minutes after dosing and a twice-daily regimen. Suggestions about addressing barriers to adherence and acceptability are provided. CONCLUSION Asenapine is a promising new medication in bipolar disorder. Asenapine in the long-term has a more favorable weight gain profile compared to olanzapine. No benefit was seen for depression symptoms, a major patient-reported concern. Some side effects do not remit after the short-term trials in at least 10% of patients.