Categorical Improvement in Depressive Symptom Severity: Results From a Randomized Controlled Trial of Cariprazine for Adjunctive Treatment of MDD

Abstract Background Patients with major depressive disorder (MDD) often do not respond to antidepressant (ADT) monotherapy alone and may require adjunctive treatment to provide adequate symptom relief. Cariprazine (CAR) is a dopamine D 3 -preferring D 3 /D 2 and serotonin 5-HT 1A receptor partial agonist approved to treat adults with schizophrenia and manic, mixed, or depressive episodes of bipolar I disorder. Post hoc analysis of data from a randomized controlled trial evaluated clinically relevant improvements in depressive symptom severity with adjunctive cariprazine in patients with MDD and inadequate response to ADT monotherapy. Methods Post hoc analysis evaluated data from a randomized, double-blind, placebo-controlled MDD trial (NCT03738215) in patients treated with CAR (1.5 mg/d or 3 mg/d) + ADT or placebo + ADT; the primary outcome was change from baseline to week 6 in Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Post hoc analysis evaluated category shifts from baseline to week 6 in MADRS severity (normal <6, mild 7–19, moderate 20–34, severe ≥35). MADRS severity shifts were reported as the percentage of patients with no change or worsened severity, 1 category improvement, ≥1 category improvement, and ≥2 category improvement. Examples of categorical shifts in depressive symptoms at week 6 include change from severe at baseline to moderate (1 category improvement) and change from severe at baseline to mild (2 category improvement). Results Of the 751 patients in the intent-to-treat (ITT) population (CAR: 1.5 mg/d=250, 3.0 mg/d=252; placebo=249), baseline MADRS severity was mild in 1.5%, moderate in 64%, and severe in 35%. Fewer CAR + ADT patients compared to placebo + ADT had no change or worsened MADRS severity at week 6 (CAR: 1.5 mg/d=32%, 3.0 mg/d=33%; placebo=42%). Approximately 68% of patients treated with CAR + ADT demonstrated a MADRS severity improvement of 1 category or greater by week 6 (CAR: 1.5 mg/d=68%, 3.0 mg/d=67%; placebo=58%). A greater percentage of patients in the CAR 1.5 mg/d group also had a 2 or greater category improvement versus CAR 3.0 mg/d or placebo 6 (CAR: 1.5 mg/d=28%, 3.0 mg/d=17%; placebo=19%). Conclusions In this post hoc analysis, CAR + ADT was associated with a greater proportion of patients with improvements in depressive symptom severity categories compared with placebo + ADT. These results may suggest that CAR + ADT is associated with clinically meaningful depressive symptom improvement in MDD patients. Funding AbbVie