Efficacy and tolerability of extended release quetiapine fumarate (quetiapine XR) monotherapy in major depressive disorder: A placebo-controlled, randomized study

BackgroundEvaluate the efficacy and tolerability of extended release quetiapine fumarate (quetiapine XR) once-daily monotherapy for patients with major depressive disorder (MDD).MethodsIn this 10-week, (8-week active treatment phase and 2-week drug-discontinuation/tapering phase), multicenter, parallel-group, placebo-controlled, double-blind, randomized, Phase III study (D1448C00003: Opal), patients initially received quetiapine XR 150 mg/day or placebo. At Week 2, inadequate responders (< 20% reduction in MADRS total score) were up-titrated to 300 mg/day quetiapine XR or matching placebo for the final 6 weeks. Primary endpoint: change from randomization to Week 8 in MADRS total score. Secondary endpoints included: MADRS response (≥ 50% reduction in total score from randomization) and changes from randomization to Week 8 in HAM-D and CGI-S.Results310 patients were randomized. At Week 8, quetiapine XR significantly reduced mean MADRS total score versus placebo (−16.49 vs −13.10, respectively; p < 0.01). Mean MADRS score was significantly reduced by quetiapine XR versus placebo at Week 1 (p < 0.05). MADRS response rates were significantly greater at Week 8 for quetiapine XR versus placebo (61.9% vs 48.0%, respectively; p < 0.05). Significant changes in HAM-D total score and CGI-S were seen at Week 8 for quetiapine XR versus placebo. Withdrawal rates due to AEs were 9.9% and 2.6% for quetiapine XR and placebo, respectively. Common AEs (> 10% any group during the randomized phase) for quetiapine XR and placebo, respectively were dry mouth (32.9% and 6.5%), sedation (21.7% and 1.9%), somnolence (20.4% and 5.2%), and headache (10.5% and 10.3%).LimitationsThe study was not designed to compare quetiapine XR 150 mg/day and 300 mg/day; it was intended to reflect dose titration that might occur in clinical practice.ConclusionsQuetiapine XR monotherapy is effective in patients with MDD, with symptom improvement seen as early as Week 1, and tolerability results consistent with the known profile of quetiapine.