Clinical Summary: Cariprazine for the Adjunctive Treatment of Major Depressive Disorder in Patients With Inadequate Response to Antidepressant Therapy: Results of a Randomized, Double-Blind, Placebo-Controlled Study
Many patients with major depressive disorder remain symptomatic despite an adequate antidepressant trial, leaving clinicians to decide whether adjunctive antipsychotic treatment is worth the tradeoff in benefit versus tolerability. This trial tests that real-world question for adjunctive cariprazine in an inadequate-response population and shows how a generally tolerable option can still fail to separate from placebo on depressive symptoms.
Key Findings
- The primary endpoint was negative at week 6: least squares mean change from baseline in MADRS total score was −13.8 for cariprazine 1.5 mg/d, −14.8 for cariprazine 3 mg/d, and −13.4 for placebo, and LS mean differences versus placebo were not statistically significant for either cariprazine dose.
- The key secondary endpoint also did not separate from placebo: at week 6, the LSMD in CGI-S score for cariprazine 3 mg/d versus placebo was −0.2 [−0.43 to 0.01], P = .0573, and CGI-S changes were not statistically significant for cariprazine versus placebo.
- Symptomatic improvement rates were numerically higher with cariprazine but not significant: MADRS response was achieved by 46% of cariprazine 1.5 mg/d patients and 48% of cariprazine 3 mg/d patients versus 41% with placebo.
- Akathisia was the main tolerability signal: scale-derived treatment-emergent akathisia was reported in 13 (5.2%) placebo-, 27 (10.8%) cariprazine 1.5 mg/d–, and 30 (12.0%) cariprazine 3 mg/d–treated patients, while scale-derived parkinsonism was 3 (1.2%), 4 (1.6%), and 4 (1.6%), respectively.
- Adverse-effect discontinuation remained low overall but was higher with the 3-mg/d dose: akathisia led to discontinuation in 2 (0.8%) patients on cariprazine 1.5 mg/d, 6 (2.4%) on cariprazine 3 mg/d, and 2 (0.8%) on placebo; mean change from baseline in weight was 0.20 kg, 0.68 kg, and 0.66 kg, respectively.
Adjunctive cariprazine 1.5 mg/d and 3 mg/d did not outperform placebo on the primary efficacy outcome over 6 weeks in adults with major depressive disorder and inadequate response to antidepressant therapy. If cariprazine is used in this setting, the clearest tradeoff is modest short-term tolerability burden from akathisia without proven week-6 efficacy in this trial.
Practice Implications
- Do not expect reliable week-6 symptom separation from placebo based on this trial alone when considering adjunctive cariprazine for major depressive disorder with inadequate antidepressant response.
- If prescribing adjunctive cariprazine, monitor early for akathisia and restlessness, since scale-derived treatment-emergent akathisia occurred in 10.8% with 1.5 mg/d and 12.0% with 3 mg/d versus 5.2% with placebo.
- Discuss dose-related tolerability with patients before uptitrating, because akathisia-related discontinuation was 0.8% with cariprazine 1.5 mg/d and 2.4% with cariprazine 3 mg/d.
- Short-term metabolic and cardiac burden appeared limited in this study, with mean weight change < 1 kg in all groups, weight increase ≥ 7% in 0.8%, 0.4%, and 2.0%, respectively, and no patient with QTcF increase > 60 msec from baseline or QTcF interval > 500 msec.
