Adjunctive brexpiprazole 1mg and 2mg daily for Japanese patients with major depressive disorder following inadequate response to antidepressants: a phase 2/3, randomized, double‐blind (BLESS) study

AimsInadequate antidepressant response interrupts effective treatment of major depressive disorder (MDD). The BLESS study evaluates the dosage, efficacy, and safety of brexpiprazole adjunctive therapy in Japanese patients with inadequate antidepressant therapy (ADT) response.MethodsThis placebo‐controlled, randomized, multicenter, parallel‐group phase 2/3 study randomized Japanese MDD patients (Hamilton Rating Scale for Depression 17‐item total score ≥ 14; historical inadequate response to 1–3 ADTs) with inadequate response to 8‐week single‐blind, prospective SSRI/SNRI treatment to 6‐week adjunctive treatment with brexpiprazole 1 mg, 2 mg, or placebo. The primary endpoint was change in Montgomery‐Åsberg Depression Rating Scale (MADRS) total score from baseline. Secondary endpoints included MADRS response, remission rate, and Clinical Global Impression‐Improvement score. Safety was comprehensively evaluated, especially regarding antipsychotic adverse events (AEs).ResultsOf 1194 screened patients, 740 were randomized and 736 (1 mg, n = 248; 2 mg, n = 245; placebo, n = 243) had ≥1 baseline/post‐baseline MADRS total score. The LSM (SE) change from baseline in MADRS total score at Week 6 by MMRM analysis was −8.5 (0.47) with brexpiprazole 1 mg, −8.2 (0.47) with brexpiprazole 2 mg, and −6.7 (0.47) with placebo (placebo‐adjusted LSM difference [95% CI]: 1 mg, −1.7 [−3.0, −0.4]; P = 0.0089; 2 mg, −1.4 [−2.7, −0.1]; P = 0.0312). Secondary efficacy results supported the primary endpoint. Brexpiprazole was generally well tolerated.ConclusionBrexpiprazole 1 mg daily was an appropriate starting dose and both 1 mg and 2 mg daily were effective and well tolerated as adjunctive therapy for Japanese MDD patients not adequately responsive to ADT.