Adjunctive Brexpiprazole 1 and 3 mg for Patients With Major Depressive Disorder Following Inadequate Response to Antidepressants: A Phase 3, Randomized, Double-Blind Study

Objective: To evaluate efficacy, safety, and tolerability of brexpiprazole adjunctive to antidepressant treatments (ADTs) in patients with major depressive disorder (as defined by DSM-IV-TR criteria) with inadequate response to ADTs. Method: Patients still depressed despite 1-3 prior ADTs followed by 8 weeks of prospective physician-determined, open-label ADT were randomized (1: 1: 1) to double-blind brexpiprazole 3 mg/d, brexpiprazole 1 mg/d, or placebo for 6 weeks. The primary efficacy end point was change in Montgomery-Asberg Depression Rating Scale (MADRS) total score from baseline to week 6. The key secondary efficacy end point was change in Sheehan Disability Scale mean score. The Hochberg procedure corrected for multiplicity. The efficacy population comprised all patients who had >= 1 dose of study drug with baseline and >= 1 postrandomization MADRS scores; the efficacy population per final protocol consisted of efficacy population patients meeting amended criteria for inadequate response throughout the 8-week prospective ADT. The study was conducted between June 2011 and September 2013. Results: In the efficacy population per final protocol, brexpiprazole 3 mg (n = 213) showed a greater improvement in MADRS total score versus placebo (n = 203; -8.29 vs -6.33; P = .0079), whereas brexpiprazole 1 mg did not (n = 211; -7.64 vs -6.33; P = .0737). The brexpiprazole groups showed comparable improvement in SDS mean score versus placebo (least squares [LS] mean difference: [1 mg] -0.49, P = .0158; [3 mg] -0.48, P = .0191). The most frequent adverse events were akathisia (4.4%, 13.5%, 2.3%), headache (9.3%, 6.1%, 7.7%), and weight increase (6.6%, 5.7%, 0.9%) in brexpiprazole 1-mg, 3-mg, and placebo groups, respectively. Mean changes from baseline in Abnormal Involuntary Movement Scale (LS mean difference = 0.08, P = .0141) and Barnes Akathisia Rating Scale (LS mean difference = 0.17, P = .0001) total scores were significantly greater with brexpiprazole 3 mg versus placebo. Conclusions: Brexpiprazole 3 mg demonstrated efficacy versus placebo in the efficacy population per final protocol. Both doses of brexpiprazole were well tolerated.