SILENOR for Insomnia. According to the American Psychiatric Association, approximately one-third of adult Americans (approximately 73 million people) are affected by insomnia. One study has found that fewer than 15% of those who suffer from insomnia are treated with prescription medications. We are developing SILENORtm for the treatment of insomnia and believe that SILENORtm will offer significant benefits over currently available therapies in the insomnia market. We in-licensed the patents and the development and commercial rights to SILENORtm and intend to develop the product for the U.S. market. SILENORtm is an oral formulation of doxepin at strengths of 1 mg to 6 mg. Doxepin has been marketed and used for over 35 years at dosages from 75 mg to 300 mg per day for the treatment of depression and anxiety. Doxepin has a well-established safety profile and we expect that our targeted dosages will be well tolerated and provide a wide margin of safety. SILENORtm is a potent blocker of a set of brain receptors known as H1 receptors, which are believed to play an important role in the regulation of sleep. The leading approved insomnia medications, Ambien, Sonata and Lunestatm, work by binding and activating a different set of brain receptors known as GABA receptors. Many of the GABA receptor-activating drugs are deemed to have the potential for abuse and are therefore designated by the U.S. Drug Enforcement Agency, or DEA, as Schedule IV controlled substances, which require additional registration and administrative controls. We have completed two placebo-controlled Phase II clinical trials, one in adults and one in elderly patients with chronic primary sleep maintenance insomnia, and we are currently enrolling patients in Phase III clinical trials. Based on our analysis of the results of our prior clinical trials, we believe that SILENORtm will induce and maintain sleep throughout the night, without next-day residual effects, in both adult and elderly patients. We expect initial data from our Phase III clinical trials to be available in mid-2006

EX-4.1 4 a12564a4exv4w1.txt EXHIBIT 4.1 Exhibit 4.1 [FACE OF CERTIFICATE] Number SP COMMON STOCK [LOGO] SOMAXON PHARMACEUTICALS, INC. INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE Shares SEE REVERSE FOR STATEMENTS RELATING TO RIGHTS, PREFERENCES, PRIVILEGES AND RESTRICTIONS, IF ANY CUSIP 834453 10 2 THIS CERTIFIES THAT is the record holder of FULLY PAID AND NONASSESSABLE SHARES OF THE COMMON STOCK, $.0001 PAR VALUE PER SHARE, OF SOMAXON PHARMACEUTICALS, INC. transferable on the books of the Corporation by the holder hereof in person or by duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate is not valid unless countersigned and registered by the Transfer Agent and Registrar. WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers. Dated: /sig/ VICE PRESIDENT & CFO [SEAL] /sig/ PRESIDENT & CEO COUNTERSIGNED AND REGISTERED: AMERICAN STOCK TRANSFER & TRUST COMPANY TRANSFER AGENT AND REGISTRAR BY AUTHORIZED SIGNATURE [REVERSE OF CERTIFICATE] The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN COM - as tenants in common TEN ENT - as tenants by the entireties JT TEN - as joint tenants with right of survivorship and not as tenants in common UNIF GIFT MIN ACT - .....(Cust)..... Custodian .....(Minor)..... under Uniform Gifts to Minors Act .....(State)..... UNIF TRF MIN ACT - .....(Cust)..... Custodian (until age .....) ......(Minor)..... under Uniform Transfers to Minors Act .....(State)..... Additional abbreviations may also be used though not in the above list. FOR VALUE RECEIVED, hereby sell, assign and transfer unto PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) Shares of the capital stock represented by the within Certificate, and do hereby irrevocably constitute and appoint Attorney to transfer the said stock on the books of the within named Corporation with full power of substitution in the premises. Dated X X NOTICE: THE SIGNATURE(S) TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME(S) AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER. Signature(s) Guaranteed By THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.