Pfizer’s Pristiq has failed to hit its primary target in a post-marketing trial involving paediatric patients with major depressive disorder.

Phase III data show that Pristiq (desvenlafaxine succinate sustained-release formulation) did now exhibit superior efficacy compared to placebo in MDD patients aged 7-17 years old, but neither did the positive control fluoxetine.

On the plus side, no new safety signals were reported with the antidepressant, Pfizer noted.

Pristiq is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) approved by the US Food and Drug Administration for the treatment of MDD in adults in 2008.

The study is the first of four late-stage trials - being conducted as part of an FDA post-marketing commitment under the Pediatric Research Equity Act - to be completed.