Servier's Valdoxan is more efficacious than both conventional selective serotonin reuptake inhibitor and serotonin noradrenaline reuptake inhibitor antidepressants, according to new data.

A pooled analysis, presented at the European College of Neuropsychopharmacology congress in Amsterdam, "supports the unique clinical signature of Valdoxan (agomelatine)", the French company claims. Four major studies involving outpatients with major depressive disorder (MDD) were analysed and in each of them, the drug, which is also known as Thymanax, offered "a distinctive profile of efficacy leading to an improved treatment of depression".

Agomelatine was compared head-to-head with three SSRIs - sertraline, escitalopram and fluoxetine - and the SNRI venlafaxine after six to eight weeks of treatment. The analysis included 643 patients treated with Valdoxan and 657 randomised to SSRI/SNRI therapy.

Servier says that agomelatine showed significantly greater antidepressant efficacy than SSRI and SNRI comparators using the HAM-D17 total score scale and percentage of responders. Overall, 71.75% of patients achieved a response to Valdoxan, versus 64.52% on SSRIs/SNRI, "a statistically significant  difference", and the Servier drug also performed significantly better in patients with severe depression.

The Paris-headquartered company also flagged up "a unique adherence to treatment" seen in the meta-analysis which found that significantly less patients on agomelatine (6.3%) withdrew from trials due to adverse events, compared to SSRIs/SNRI (10.5%). Servier quoted Siegfried Kasper of the University Hospital in Vienna as saying that "this new data adds to the already compelling clinical evidence for Valdoxan’s efficacy in treating MDD, even in its severe forms". He said that its "excellent antidepressant efficacy – coupled with a unique, ‘first-of-a-kind’ mode of action – marks Valdoxan out as an exciting and innovative treatment".

Raymond Lam of the University of British Columbia in Vancouver, added that "although we have a large armoury at our disposal, gaps still exist in modern depression management”. He went on to claim that "as the first-ever antidepressant to target melatonergic MT1 and MT2 receptors and 5-HT2C receptor, with no impact on serotonin levels, Valdoxan offers a new approach to tackling this devastating disease.”

Valdoxan received European Union marketing authorisation in February 2009 and is now available for the treatment of adult patients with MDD in several countries worldwide.