Evaluate the effects of once-daily extended release quetiapine fumarate (quetiapine XR) monotherapy in patients with major depressive disorder (MDD) according to disease severity.

Pooled data (quetiapine XR 50, 150 and 300mg/day doses combined) from four 6- or 8-week placebo-controlled quetiapine XR monotherapy studies (D1448C00001, D1448C00002, D1448C00003, D1448C00004) were analysed. Key inclusion criterion for all 4 studies: HAM-D total score ≥22. Primary endpoint: change from randomisation in Montgomery-Åsberg Depression Rating Scale (MADRS) total score. A post-hoc analysis assessed change from randomisation in MADRS total score and MADRS response (≥ 50% reduction in MADRS total score) at endpoint (Week 6 or Week 8) in 6 severity cohorts (defined by a MADRS total score at randomisation ≥24, ≥26, ≥28, ≥30, ≥32 or ≥34).

1752 patients (comprising the l’ all patients’ group) were evaluated (MADRS score ≥24 at randomisation, n=1601; ≥26, n=1467; ≥28, n=1269; ≥30, n=1038; ≥32, n=745; ≥34, n=500). Quetiapine XR significantly reduced mean MADRS total score at endpoint in lrsquo;all patients’ (p< 0.001 vs placebo) and in all 6 severity cohorts (≥24, ≥26, ≥28, ≥30 and ≥32, p< 0.001 vs placebo; ≥34, p< 0.01 vs placebo). MADRS response rates were significantly higher in the quetiapine XR group vs placebo in the ‘all patients’ group (p< 0.001 vs placebo) and in all 6 severity cohorts (≥24, ≥26, ≥28, ≥30 and ≥32, p< 0.001 vs placebo; ≥34, p=0.001 vs placebo).

Quetiapine XR monotherapy significantly improved depressive symptoms in patients with MDD irrespective of disease severity, including the most severe levels of depression.

AstraZeneca funded