A placebo-controlled study of three agomelatine dose regimens (10 mg, 25 mg, 25-50 mg) in patients with major depressive disorder.

A randomised placebo-controlled "dose relation study" was conducted in 549 patients who met the criteria for major depressive disorder, to evaluate the efficacy and safety of three doses regimens of agomelatine during 6 weeks: low fixed dosage (10 mg/day, n=133), fixed dosage (25 mg/day, n=138) and a flexible dosage with up-titration in case of insufficient improvement at week 2 (25-50 mg/day, n=137). At last post-baseline assessment, there were significant and incremental placebo-agomelatine differences on mean HAM-D17 total scores in favour of each agomelatine dose regimen (2.46 ± 0.76 points, p=0.001 at 10 mg; 4.71+0.75 points, p<0.0001 at 25 mg and 4.92 ± 0.76 points, p<0.0001 at 25-50 mg) with statistically significant differences between 25 mg and 25-50 mg dose regimens compared to the 10 mg dose. The response rate according to HAM-D17 was significantly higher in patients taking agomelatine than those taking placebo (difference of 16.1% at 10 mg p=0.005; 25.9% and 27.4% respectively at 25 mg and 25-50 mg, p<0.0001). The benefit of agomelatine was demonstrated in the subgroup of severely depressed patients in the 25 mg and 25-50 mg/day regimens. Consistent clinical response according to CGI variables and better social functioning were found in patients receiving agomelatine. All dose regimens of agomelatine were well tolerated and no unexpected adverse event was reported. This study provides evidence of a dose effect for agomelatine between 10 mg and the therapeutic dose regimen of agomelatine 25-50 mg: the efficacy of the higher dose regimens being more efficacious than the lowest (10 mg) daily dose. The data support a definitive statement regarding the utility of 25 mg as the threshold dose for initiating agomelatine in depressed patients.

The efficacy of agomelatine in elderly patients with recurrent major depressive disorder: a placebo-controlled study.

OBJECTIVE: The present placebo-controlled study evaluated the efficacy, tolerability, and safety of 8-week treatment with agomelatine (25-50 mg/d by mouth) in elderly patients with major depressive disorder (MDD). METHOD: Elderly outpatients aged ≥ 65 years with a primary diagnosis of moderate to severe episode of recurrent MDD (DSM-IV-TR) were recruited in 27 clinical centers in Argentina, Finland, Mexico, Portugal, and Romania from November 2009 to October 2011. The primary outcome measure was the 17-item Hamilton Depression Rating Scale (HDRS17) total score. RESULTS: A total of 222 elderly patients entered the study (151 in the agomelatine group, 71 in the placebo group), including 69 patients aged 75 years and older. Agomelatine improved depressive symptoms in the elderly population, as evaluated by the HDRS17 total score, in terms of last postbaseline value (agomelatine-placebo difference: mean estimate [standard error] = 2.67 [1.06] points; P = .013) and response to treatment (agomelatine, 59.5%; placebo, 38.6%; P = .004). The agomelatine-placebo difference according to the Clinical Global Impressions-Severity of Illness scale (CGI-S) score was 0.48 (0.19). The agomelatine-placebo difference (estimate [standard error]) for remission on the HDRS17 was 6.9% (4.7%) and did not achieve statistical significance (P = .179, post hoc analysis). Clinically relevant effects of agomelatine were confirmed on all end points in the subset of severely depressed patients (HDRS17 total score ≥ 25 and CGI-S score ≥ 5 at baseline). Agomelatine was well tolerated by patients, with only minimal distinctions from placebo. CONCLUSIONS: The present study provides the first evidence that an 8-week treatment with agomelatine 25-50 mg/d efficiently relieves depressive symptoms and is well tolerated in elderly depressed patients older than 65 years. TRIAL REGISTRATION: Controlled-Trials.com identifier: ISRCTN57507360.