October 19, 2005

Sepracor has initiated a Phase I, single-blind, randomized, placebo-controlled safety, tolerability and pharmacokinetic study for SEP-225289 for the treatment of major depressive disorder (MDD).

Based on preclinical study data, SEP-225289 has the potential to be a leading drug candidate in the newly emerging field of triple reuptake inhibitors. SEP-225289 has been shown in preclinical studies to be a potent and balanced reuptake inhibitor of serotonin, norepinephrine and dopamine. Serotonin, norepinephrine and dopamine are neurotransmitters associated with depression. There are currently no marketed treatments for MDD that inhibit reuptake of all three neurotransmitters. Studies suggest that a triple mechanism of action may provide a broader spectrum of therapy than currently marketed antidepressants.

It is estimated that approximately 18 million Americans have a depressive disorder. MDD is described as when five or more symptoms of depression are present for at least two weeks. These symptoms include feeling sad, hopeless, worthless, or pessimistic. In addition, people with major depression often have behavior changes, such as new eating and sleeping patterns. Evidence suggests that between 29 and 46 percent of depressed patients fail to fully respond to antidepressant treatment with marketed drugs.