Early Improvement with Vortioxetine Predicts Response and Remission: A Post Hoc Analysis of Data from a Clinical Trial Conducted in Japan

Several weeks of treatment with an antidepressive agent may be required before efficacy is demonstrated in patients with major depressive disorder. This study investigated the predictive value of early partial improvement with vortioxetine for treatment response and remission. This was a post hoc analysis of an 8-week, randomized, double-blind, placebo-controlled, Phase 3 study of vortioxetine (10 mg or 20 mg) in Japanese patients aged 20-75 years with recurrent major depressive disorder and a Montgomery-Åsberg Depression Rating Scale (MADRS) score of at least 26. The key outcomes were the predictive value of early partial improvement (reduction in MADRS total score of ≥20% from baseline to week 2) with vortioxetine for MADRS response (≥50% decrease in score from baseline) and remission (decrease in score to ≤10) at week 8. Relevant data were available for 478 patients; 62/158 patients receiving placebo, 71/162 receiving vortioxetine 10 mg, and 66/158 receiving vortioxetine 20 mg were early improvers. Early improvers receiving vortioxetine (10 mg or 20 mg) were more likely than non-early improvers to achieve a week 8 response (71.2-73.2% vs 29.7-38.0%) or remission (50.7-51.5% vs 17.4-18.7%). Positive predictive values for response and remission with vortioxetine were ~70% and ~50%, respectively; negative predictive values were ~70% and ~80%, respectively. Improvement with vortioxetine may be predicted by early partial improvement in MADRS score. Some patients may benefit from longer-term treatment even without early improvement, another finding that may aid clinical decision-making. ClinicalTrials.gov registration for primary study: NCT02389816.