Pfizer Reports Top Line Results from a Phase III Study Evaluating Desvenlafaxine Succinate Sustained-Release Formulation

Pfizer has announced the top line results from a Phase III study which evaluated the efficacy, safety, and tolerability of Pristiq (desvenlafaxine succinate sustained-release formulation) in pediatric patients ages 7 to 17 with Major Depressive Disorder (MDD).

The study did not meet its primary objective to demonstrate superior efficacy of desvenlafaxine succinate sustained-release formulation compared to placebo.

This is the first completed study of four Phase III pediatric trials being conducted as part of an FDA post-marketing commitment under the Pediatric Research Equity Act (PREA).

About the Study

The study was a randomized, double-blind, placebo-controlled, fluoxetine-referenced study designed to evaluate the efficacy, safety, and tolerability of desvenlafaxine succinate sustained-release formulation in pediatric outpatients ages 7–17 with MDD. A total of 340 subjects were randomized. The patient population was comprised of 38.3C% children (7–11 years of age) and 61.7% adolescents (12–17 years of age). This study included three treatment arms: desvenlafaxine succinate sustained-release formulation (weight-based dosing to achieve pediatric exposures approximating exposures in adults receiving 35 mg/day), fluoxetine (20 mg/day), and placebo.

Efficacy results indicate that both desvenlafaxine succinate sustained-release formulation and the positive control, fluoxetine, were not statistically significantly different from placebo.

There were no new safety signals identified. Adverse events occurring after the start of treatment in the desvenlafaxine succinate sustained-release formulation group were generally consistent with those observed in both the Phase IIa pediatric MDD safety studies and the studies of desvenlafaxine succinate sustained-release formulation-treated adults with MDD.

Full results from the study will be submitted for publication.