Somaxon's Silenor Phase 3 clinical data accepted for publication in Sleep, Sleep Medicine journals

Somaxon Pharmaceuticals, Inc. (Nasdaq: SOMX), a specialty pharmaceutical company focused on the in-licensing, development and commercialization of proprietary branded pharmaceutical products and late-stage product candidates for the treatment of diseases and disorders in the central nervous system therapeutic area, today announced that detailed results from two Phase 3 clinical trials of the company's product Silenor® (doxepin) have been accepted for publication in peer-reviewed scientific journals.

“These articles detail Phase 3 clinical data demonstrating that doxepin showed significant improvements compared to placebo on multiple efficacy endpoints relating to insomnia, with a favorable safety and tolerability profile”

The article entitled "Efficacy and Safety of Doxepin 1 mg and 3 mg in a 12-week Sleep Laboratory and Outpatient Trial of Elderly Subjects with Chronic Primary Insomnia," is currently available on-line and is expected to be published in Sleep in the next two months.

This Phase 3 clinical trial enrolled 240 elderly subjects, and efficacy assessments evaluated both objective polysomnography (PSG) and subjective measures of sleep. Subjective efficacy assessments were made both in the sleep laboratory and on an outpatient basis. Safety and efficacy were evaluated over a twelve week period, which the company believes represents the longest clinical trial reported to date for insomnia that evaluated efficacy in both the sleep laboratory and outpatient settings.

Both doses of Silenor achieved statistical significance for objective measures of sleep maintenance in the sleep laboratory setting, including the primary endpoint of Wake After Sleep Onset (WASO), and for subjective measures of sleep maintenance and sleep onset in the outpatient setting. Effects at week twelve were generally statistically significant and similar to or improved from those observed at week one.

With respect to safety, the incidence of adverse events in this trial was comparable to placebo. There were no statistically significant differences relative to placebo in next day residual effects, no amnesia or memory impairment was reported in the Silenor treated group, and there were no differences compared to placebo in weight gain.

Somaxon's other article that has been accepted for publication, entitled "Efficacy and Safety of Doxepin 6 mg in a Model of Transient Insomnia," is expected to be published in Sleep Medicine in the next three months.

This Phase 3 clinical trial enrolled 565 adults in a sleep laboratory setting using a phase-advance, first night assessment model of induced transient insomnia. Efficacy assessments evaluated both objective PSG and subjective measures of sleep. The results demonstrated that Silenor achieved statistical significance for objective and subjective measures of sleep onset, including for the primary endpoint of Latency to Persistent Sleep (LPS), and sleep maintenance.

The incidence of adverse events was comparable to placebo. There were no reports of amnesia, memory impairment or anticholinergic effects, and there were no clinically meaningful effects on measures of next day impairment.

The articles represent a subset of the data from Somaxon's completed clinical development program underlying the approved New Drug Application (NDA) for Silenor for the treatment of insomnia characterized by difficulties with sleep maintenance.

"These articles detail Phase 3 clinical data demonstrating that doxepin showed significant improvements compared to placebo on multiple efficacy endpoints relating to insomnia, with a favorable safety and tolerability profile," said Thomas Roth, Ph.D., chief, division head, Sleep Disorders & Research Center, Henry Ford Hospital and an author on both articles. "This data, together with the remainder of the data from Somaxon's clinical program, suggests that Silenor is an important option available for the management of insomnia patients."

"The acceptance of these articles for publication is another milestone in our commercialization plan for Silenor as we look forward to an October launch," said Richard W. Pascoe, Somaxon's president and chief executive officer. "The articles, which describe Silenor's safety and efficacy in the elderly and adult insomnia populations, together with others that we hope to have published in the future, will serve to educate healthcare providers on the comprehensive data that resulted from our Silenor clinical program."