Meta-analyses of the efficacy of asenapine for acute schizophrenia: comparisons with placebo and other antipsychotics.

CONTEXT: Asenapine is an approved treatment for schizophrenia in the United States.
OBJECTIVE: Meta-analyses were conducted to evaluate the efficacy of asenapine in acute schizophrenia compared with placebo and other antipsychotics. DATA SOURCES: Four asenapine trials from the asenapine development program were pooled for the meta-analysis. To compare asenapine versus placebo treatment effect with other antipsychotics, we added integrated asenapine data to a previously published meta-analysis. For comparative efficacy of asenapine versus other second-generation antipsychotics (SGAs), data from a second published meta-analysis were combined with the 4 asenapine trials. DATA ANALYSES: To evaluate efficacy, mean change in Positive and Negative Syndrome Scale (PANSS) total score was examined in asenapine and other antipsychotics. To assess clinical relevance, PANSS response rates and associated odds ratios (ORs) for treatment response were assessed. To assess the relative efficacy of SGAs, a network meta-analysis with PANSS total score change was conducted by using data from the 2 published meta-analyses together with asenapine data.
RESULTS: Asenapine was superior to placebo with regard to mean change in PANSS total score (last observation carried forward [LOCF]: -3.6, P = .002; mixed model for repeated measures [MMRM]: -4.1, P = .001), an effect comparable to active controls from the same trials (LOCF: -4.0, P = .002; MMRM: -4.8, P = .001). PANSS responder rates were significantly better with asenapine versus placebo (OR, 1.9; P < .001) and comparable to active controls (OR, 1.7; P = .002). Effect sizes for asenapine were somewhat lower than those reported in the literature for other SGAs. Network meta-analysis also demonstrated that the efficacy of asenapine was comparable to that of other SGAs; estimated differences between asenapine and other SGAs ranged from 3.9 points (95% CI, 0.3 to 7.4) greater than ziprasidone to 2.9 points (95% CI, -0.1 to 5.9) less than olanzapine.
CONCLUSIONS: These meta-analyses indicate that the efficacy of asenapine for acute schizophrenia is superior to placebo and comparable to several other SGAs. © Copyright 2012 Physicians Postgraduate Press, Inc.