Somaxon Pharmaceuticals, Inc. (Nasdaq: SOMX) today announced that oral nalmefene hydrochloride, an opiate antagonist under development by the company, demonstrated positive results in a pilot Phase 2 clinical trial for smoking cessation. In a single center, randomized, placebo-controlled study in which 76 smokers were enrolled, patients in the nalmefene 40mg group demonstrated numerically higher abstinence rates at all timepoints relative to placebo. Patients in the nalmefene 80mg group did not consistently achieve abstinence rates that were numerically superior to placebo. The study was not powered to demonstrate statistical significance.

Nalmefene was generally well tolerated, with an adverse event profile similar to that observed in studies previously conducted with nalmefene. The most commonly reported adverse events were insomnia and nausea. The adverse events tended to be transient in nature and largely resolved after the first week on study drug. Elevation in liver enzymes was observed with a similar frequency in all groups.

Somaxon's Chief Medical Officer Phil Jochelson, MD commented, "We are encouraged by the results of our first smoking cessation clinical study which was designed to be exploratory in nature. We are intrigued with the observation that the nalmefene 40 mg treated patients maintained higher abstinence rates relative to placebo."

Ken Cohen, Somaxon's President and Chief Executive Officer commented, "Nalmefene is a promising compound. We are currently studying this product in a large clinical trial for the treatment of pathological gambling. We intend to await the results of that trial, which we expect early next year, before we determine our further clinical development plans. The results of this pilot smoking cessation trial give us the opportunity to potentially develop nalmefene for multiple indications in large markets with unmet medical needs."

About Smoking

Cigarette smoking remains the leading preventable cause of illness and premature death in the United States. In 2005, the U.S. Centers for Disease Control and Prevention estimated that approximately 45 million, or 22%, of adults in the United States are smokers. The impact of nicotine dependence in terms of morbidity, mortality and economic costs to society is enormous. According to the Surgeon General, tobacco usage kills more than 440,000 people in the United States annually. Smoking is linked to an estimated $75 billion in medical expenditures in the United States per year. When indirect costs such as lost productivity due to smoking are considered, the costs increase significantly to approximately $158 billion. Nearly 41% of smokers attempt to quit smoking each year but only about 10% achieve and maintain abstinence.

About Nalmefene

Nalmefene, an opioid antagonist, is approved and has been used for over 10 years in the United States in an intravenous form for the reversal of opioid drug effects. Somaxon in-licensed the North American development and commercial rights to an oral form of nalmefene and patents for its use in the treatment of impulse control disorders, nicotine dependence and other conditions. The impulse control disorder category includes a number of serious conditions, including pathological gambling, kleptomania, pyromania, intermittent explosive disorder and compulsive buying. There are no FDA approved therapies for any of these disorders. The University of Chicago's 1999 Gambling Impact and Behavior Study estimates that in the United States alone, there are approximately 2.5 million pathological gamblers, 3 million problem gamblers and an additional 15 million people who are at-risk gamblers. In a multi-center Phase 2 clinical trial conducted by Somaxon's licensor, nalmefene was shown to be statistically superior to placebo in limiting gambling behavior and reducing the frequency and intensity of gambling thoughts/urges. Based on these results, Somaxon has initiated a confirmatory Phase 2/3 clinical trial for pathological gambling. The company expects results from the pathological gambling trial to be available in early 2007.

About Somaxon Pharmaceuticals, Inc.

Headquartered in San Diego, CA, Somaxon Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on the in-licensing and development of proprietary product candidates for the treatment of diseases and disorders in the fields of psychiatry and neurology. Somaxon's lead product candidate, SILENOR(TM) (doxepin HCl), is in Phase 3 clinical trials for the treatment of insomnia. Nalmefene HCl is in a Phase 2/3 clinical trial for pathological gambling and has completed a pilot Phase 2 trial for smoking cessation. Acamprosate Ca, a potential treatment for movement disorders, is currently in formulation development.

For more information, please visit the company's web site at somaxon.

Somaxon cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by Somaxon that any of its plans will be achieved. Actual results may differ materially from those set forth in this release due to the risks and uncertainties inherent in Somaxon's business, including, without limitation: the potential for nalmefene to receive regulatory approval for one or more indications on a timely basis or at all; the progress and timing of Somaxon's clinical trials, including the potential to replicate in future trials the results observed in the pilot smoking cessation trial for nalmefene and the ability to demonstrate sufficient therapeutic efficacy and safety for SILENOR(TM) and nalmefene in Somaxon's other pending trials; the market potential for smoking cessation, compulsive gambling, insomnia and other target markets, and Somaxon's ability to compete in those markets; the scope and validity of patent protection for Somaxon's product candidates; Somaxon's ability to attract and retain key personnel; and other risks detailed in Somaxon's prior press releases as well as in periodic filings with the Securities and Exchange Commission.

You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement and Somaxon undertakes no obligation to revise or update this news release to reflect events or circumstances after the date hereof.

This caution is made under the safe harbor provisions of Section 21E of the Private Securities Litigation Reform Act of 1995.

Somaxon Pharmaceuticals, Inc.
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