A randomised, double-blind, placebo controlled, duloxetine-referenced, fixed-dose study of three dosages of Lu AA21004 in acute treatment of major depressive disorder (MDD)

The efficacy, safety, and tolerability of Lu AA21004 versus placebo, using duloxetine as active reference, in patients with DSM-IV-TR diagnosed major depressive disorder (MDD) were evaluated in this 8-week, multi-site study. Patients (n = 766) had a baseline Montgomery–Åsberg Depression Rating Scale (MADRS) total score ≥ 26 and were randomly assigned (1:1:1:1:1) to 2.5, 5 or 10 mg Lu AA21004, placebo, or 60 mg duloxetine. The 5 mg and 10 mg doses of Lu AA21004 were tested separately versus placebo at p ≤ 0.025 in a pre-specified order. In the pre-defined primary efficacy analysis [mean change from baseline in MADRS total score at Week 8, full analysis set, ANCOVA, last observation carried forward (LOCF)], the differences to placebo (n = 145) of − 1.7 (Lu AA21004 5 mg, n = 155) and − 1.5 points (Lu AA21004 10 mg, n = 151) were not statistically significant; nor were those for Lu AA21004 2.5 mg (− 1.4 points, n = 155) or duloxetine (− 2.0 points, n = 149). Using mixed model, repeated measures (MMRM) analyses of the primary endpoint and most secondary endpoints were supportive of likely efficacy for Lu AA21004 5 mg and 10 mg and duloxetine. Treatment-emergent adverse events led to the withdrawal of 72 patients: 8% (placebo), 12% (duloxetine), and 6%, 11% and 9% in the Lu AA21004 groups (2.5 mg, 5 mg and 10 mg, respectively). The most common adverse events were nausea, headache, dizziness, and dry mouth. No clinically relevant changes were seen in vital signs, weight, ECG, or laboratory results. In summary, none of the active treatment groups, including duloxetine, separated from placebo in the primary analysis in this 'failed' study. Findings on secondary outcome measures, using MMRM instead of LOCF, were supportive of likely efficacy for Lu AA21004 5 mg and 10 mg and duloxetine. Lu AA21004 (2.5, 5 and 10 mg) was well tolerated.