Efficacy of Adjunctive Brexpiprazole in Adults With MDD: Improvement of Patient Engagement Based on Selected Items From the Inventory of Depressive Symptomatology Self-Report (IDS-SR) Scale

Objective: These post-hoc analyses used relevant items from the IDS-SR to explore whether treatment with adjunctive brexpiprazole in patients with MDD has potential to improve a new concept of patient engagement.

Methods: In three short-term studies (Pyxis [NCT01360645], Polaris [NCT01360632] and Sirius [NCT02196506]), patients with MDD and an inadequate response to ADT were randomized to ADT plus adjunctive brexpiprazole, or ADT plus adjunctive placebo for 6 weeks. The concept of engagement was hypothetically defined by IDS-SR items 8, 15, 16, 17, 19, 20, 21, 22, 23, and 29 and subsequently tested using data pooled for patients allocated to brexpiprazole 2–3 mg/day, and to placebo. Mean changes from baseline on the selected IDS-SR items were analyzed using a mixed model repeated measures approach. A principal component analysis (PCA) was performed to validate whether changes in the selected items clustered together. Standardized effect sizes were also calculated.

Results: The IDS-SR scale was completed at baseline by a total of 1,162 patients, ADT+brexpiprazole 2–3 mg/day (n=579); ADT+placebo (n=583). At Week 6, an improvement (p<0.05) was observed on 8 out of the 10 selected items from the IDS-SR scale, with LS mean differences versus placebo in the range -0.09 to -0.18. The standardized effect size for the selected items combined was -0.23 for brexpiprazole versus placebo. PCA showed that the selected items cluster together.

Conclusion: Validation that engagement items cluster supports the idea that adjunctive brexpiprazole has the potential to improve patient engagement in addition to improving depressive symptoms.

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