Investigating Patient Characteristics as Predictors of Engagement Response to Adjunctive Brexpiprazole in Major Depressive Disorder

Background: Treatment with adjunctive brexpiprazole in major depressive disorder (MDD) has been shown to improve 'patient engagement', a concept related to one’s energy, interest, and outlook. The aim of this study was to examine whether specific patient characteristics were predictive of an engagement response in MDD.

Methods: Data were from three 6-week, placebo-controlled trials (Pyxis: NCT01360645, Polaris: NCT01360632, and Sirius: NCT02196506) in which patients received 2 or 3mg brexpiprazole as adjunctive antidepressant treatment. A subscale of 10 items from the IDS-SR (Inventory of Depressive Symptoms - Self Report) was used to measure patient engagement. Using Pearson correlation and logistic regression analyses, we tested for associations between change from baseline to Week 6 on the engagement subscale and patient characteristics: gender, age, BMI, duration of current episode, number of lifetime episodes, number of treatment failures, anxious distress, anxious depression, and baseline score on each item of the MADRS (Montgomery-Asberg Depression Rating Scale).

Results: For almost all the patient characteristics tested, there were no significant associations with change from baseline on the IDS-SR engagement subscale. One characteristic that did show an association for patients in the brexpiprazole treatment group was MADRS item 7-lassitude. Subjects with higher scores at baseline had greater improvement on the engagement subscale.

Conclusion: These results demonstrate how an engagement response to brexpiprazole in MDD is not specific to only certain types of patients, but rather can occur in a wide range of individuals. Notably, patients with high levels of baseline lassitude were more likely to show improved engagement.