Efficacy of Adjunctive Brexpiprazole in Major Depressive Disorder: A Pooled Response Quartile Analysis

Background: We assessed varying levels of response to brexpiprazole adjunctive to standard antidepressant therapy (ADT).

Method: Post hoc analysis of 3 similarly designed randomized, double-blind, placebo-controlled Phase 3 studies investigating the efficacy and safety of adjunctive brexpiprazole to standard ADT in patients with major depressive disorder (MDD) with inadequate response to 1–3 ADTs. Quartile response categories were defined based on percent reduction in Montgomery–Åsberg Depression Rating Scale (MADRS) Total score after 6 weeks of treatment, with a < 25% decrease for minimal, ≥25 to < 50% decrease for partial, ≥50% to < 75% decrease for moderate, and ≥75% decrease for robust response to treatment. The proportion of ADT+placebo (n=583) vs. ADT+brexpiprazole (n=579) patients achieving each response category was compared using the Cochran–Mantel–Haenszel test.

Results: Compared with ADT+placebo, adjunctive brexpiprazole 2–3 mg/day treatment was associated with a greater proportion of patients achieving a partial response (30% vs. 24%, p=0.013), moderate response (17% vs. 14%, p=0.071), and robust response (11% vs. 7%, p=0.018). Furthermore, compared with ADT+placebo, adjunctive brexpiprazole treatment was associated with a lower proportion of patients achieving a minimal response (28% vs. 32%, p=0.074). Considering the time course of improvement, a greater proportion of patients receiving ADT+brexpiprazole had partial, moderate or robust response than patients receiving ADT+placebo as early as Week 1 (17% vs. 11%, p=0.0016).

Conclusion: Nearly 60% of patients treated with ADT+brexpiprazole achieved partial, moderate or robust response compared with 45% in the ADT+placebo group.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.