FDA Extends Review of Somaxon Pharmaceuticals New Drug Application for Silenor® (Doxepin) by up to Three Months

Somaxon Pharmaceuticals, Inc. (Nasdaq: SOMX), 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, today announced that it received notification that the U.S. Food and Drug Administration (FDA) will not be able to complete its review of the company’s New Drug Application (NDA) for Silenor^® (doxepin) by the Prescription Drug User Fee Act (PDUFA) date of December 1, 2008. The FDA indicated that the review would be extended for up to three additional months, resulting in a new PDUFA date of February 28, 2009.

“We continue to believe that the NDA we have submitted is sufficient to support a determination by the FDA that Silenor is approvable for the treatment of insomnia,” said Richard W. Pascoe, Somaxon’s president and chief executive officer. “The FDA did not raise any issues with the data contained in the NDA, nor did they request that we conduct any additional studies. We have had numerous interactions with the FDA during its review of the NDA, and we have been very responsive to all questions posed during the review cycle. We will continue to work closely with the FDA toward the potential approval of Silenor.”

“We remain confident in Silenor’s potential as a highly differentiated treatment option for patients suffering from insomnia, and we believe that it would be well-received by physicians and patients, if it is approved by the FDA,” continued Pascoe. “In order to ensure that our financial position is as strong as possible during the remainder of the NDA review period, we will undertake significant cost reduction measures, while continuing to evaluate financing alternatives available to us.”

About Silenor^®

Silenor is a low-dose (1 mg, 3 mg, 6 mg) oral tablet formulation of doxepin that is patent protected for use in insomnia. Physicians have prescribed doxepin for more than 35 years for the treatment of depression and anxiety at dosages typically ranging from 75 mg to 300 mg per day. Based upon the controlled clinical trials of Silenor completed by Somaxon, the company believes that Silenor will be well tolerated by patients. In addition, the FDA has indicated that it will recommend that Silenor not be scheduled as a controlled substance.

About the Silenor NDA and Background of the Development Program

Somaxon submitted its NDA for Silenor under Section 505(b)(2) of the Federal Food, Drug, and Cosmetic Act, which allows the company to rely on published literature reports or the FDA’s findings of safety and efficacy for other formulations of doxepin that have previously been approved by the FDA. The NDA included all of the data from the company’s clinical development program, including data from each of Somaxon’s four Phase 3 clinical trials evaluating Silenor for the treatment of insomnia. The following summarizes the results from these Phase 3 clinical trials:

• In a clinical trial to evaluate Silenor in the treatment of 229 adults with chronic insomnia in a sleep laboratory setting, Silenor demonstrated a statistically significant improvement compared with placebo on the primary endpoint of Wake After Sleep Onset (WASO), as well as a range of secondary endpoints including Latency to Persistent Sleep (LPS) and Total Sleep Time (TST).
• In a clinical trial to evaluate Silenor in the treatment of 565 healthy adults experiencing transient insomnia in a sleep laboratory setting, Silenor demonstrated a statistically significant improvement compared with placebo on the primary endpoint of LPS, as well as a range of secondary endpoints including WASO, TST and Latency to Sleep Onset (LSO).
• In a clinical trial to evaluate Silenor in the treatment of 255 elderly patients with primary sleep maintenance insomnia in an outpatient setting, Silenor demonstrated a statistically significant improvement compared with placebo on the primary endpoint of subjective Total Sleep Time (sTST), as well as a range of secondary endpoints including subjective Wake After Sleep Onset and Sleep Quality.
• In a clinical trial to evaluate long-term use of Silenor in 240 elderly patients in both the sleep laboratory and outpatient settings, Silenor demonstrated a statistically significant improvement compared with placebo in the primary endpoint of WASO, as well as a range of secondary endpoints including TST, Sleep Efficiency, sTST, and LSO.
• The clinical trial results also demonstrated a favorable safety and tolerability profile for Silenor, with the overall incidence of adverse events comparable to placebo, a low discontinuation rate and no evidence of dependency, withdrawal, tolerance or amnesia. The most frequently reported adverse events across all of the Phase 3 clinical trials were somnolence, upper respiratory tract infection, sinusitis, nausea and hypertension; of these, somnolence was the only adverse event that was dose-related.

Conference Call Information and Forward-Looking Statements

On Monday, November 24, 2008, the company will host a conference call with interested parties beginning at 6:00 a.m. PT (9:00 a.m. ET). The conference call will be available to interested parties through a live audio Internet broadcast at http://investors.somaxon.com/eventdetail.cfm. The call will also be archived and accessible at this site for approximately two weeks. Alternatively, callers may participate in the conference call by dialing 800-218-8862 (domestic) or 303-262-2062 (international). A telephonic replay will be available for approximately one week following the conclusion of the call by dialing 800-405-2236 (domestic) or 303-590-3000 (international), and entering passcode 11122746.

Discussion during the conference call may include forward-looking statements regarding such topics as, but not limited to, the status of the FDA review of the NDA for Silenor, the company’s financial status and performance, and any comments the company may make about its future plans or prospects in response to questions from participants on the conference call.

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. A New Drug Application (NDA) for Silenor^® (doxepin), Somaxon’s drug candidate for insomnia, has been filed with the U.S. Food and Drug Administration and currently is under review.

For more information, please visit the company’s web site at www.somaxon.com.

Somaxon cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. For example, statements regarding the potential approval of the NDA for Silenor and the potential commercialization of Silenor 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 Silenor to receive regulatory approval for one or more indications on a timely basis or at all; the potential for the FDA to impose non-clinical, clinical or other requirements to be completed before or after regulatory approval of Silenor; Somaxon’s ability to demonstrate to the satisfaction of the FDA that potential NDA approval of Silenor is appropriate prior to the completion of standard, long-term carcinogenicity studies, given the context of completed trials and pending studies; the timing and results of non-clinical studies for Silenor, and the FDA’s agreement with Somaxon’s interpretation of such results; Somaxon’s ability to successfully commercialize Silenor, if it is approved by the FDA; Somaxon’s ability to raise sufficient capital and meet its obligations to parties with whom it contracts relating to financing activity, and the impact of any such financing activity on the level of Somaxon’s stock price; the potential to enter into and the terms of any strategic transaction relating to Silenor; the scope, validity and duration of patent protection and other intellectual property rights for Silenor; whether any approved label for Silenor is sufficiently consistent with such patent protection to provide exclusivity for Silenor; Somaxon’s ability to operate its business without infringing the intellectual property rights of others; unexpected findings relating to Silenor that could delay or prevent regulatory approval or commercialization, or that could result in recalls or product liability claims; other difficulties or delays in development, testing, manufacturing and marketing of and obtaining regulatory approval for Silenor; the market potential for insomnia treatments, and Somaxon’s ability to compete within that market; and other risks detailed in Somaxon’s prior press releases as well as in its 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 Securities Exchange Act of 1934.