Introduction: We evaluated the efficacy and safety of brexpiprazole for the treatment of agitation in Alzheimer's dementia (AAD) in Japanese patients.

Methods: This was a phase 2/3 multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Patients with AAD were randomized to receive brexpiprazole 1 mg/day or 2 mg/day, or placebo (3:4:4) for 10 weeks.

Results: For the primary endpoint (change in Cohen-Mansfield Agitation Inventory [CMAI] total score from baseline to Week 10), both brexpiprazole 1 mg and 2 mg groups demonstrated statistically significant improvement versus placebo (2 mg: least squares [LS] mean difference -7.2 [95% confidence interval (CI): -10.0 to -4.3], p-value < 0.0001, 1 mg: LS mean difference -3.7 [95% CI: -6.8 to -0.7], p-value = 0.0175). The incidences of treatment-emergent adverse events reported in the brexpiprazole 1 mg, 2 mg, and placebo groups were 76.8%, 84.6%, and 73.8%, respectively.

Discussion: Brexpiprazole 1 mg/day and 2 mg/day for 10 weeks was efficacious and well tolerated. HIGHLIGHTS: Brexpiprazole treatment for 10 weeks improved agitation in Alzheimer's dementia. The efficacy of brexpiprazole 1 mg/day has been confirmed for the first time. The incidence of adverse events was higher compared to the previous studies. Both brexpiprazole 1 mg/day and 2 mg/day were generally well tolerated.