AGREEMENT
Exhibit 99.1
Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the
undersigned hereby agree that only one statement containing the information required by Schedule
13G need be filed with respect to the ownership by each of the undersigned of the shares of Common
Stock of Somaxon Pharmaceuticals, Inc.
Dated: July 16, 2009
| PROSPECT VENTURE PARTNERS III, L.P. |
||||
| By: | Prospect Management Co. III, L.L.C. | |||
| Its: | General Partner | |||
| /s/ Xxxx Xxxxxxxx | ||||
| Xxxx Xxxxxxxx | ||||
| Attorney-in-Fact | ||||
| PROSPECT MANAGEMENT CO. III, L.L.C. |
||||
| /s/ Xxxx Xxxxxxxx | ||||
| Xxxx Xxxxxxxx | ||||
| Attorney-in-Fact | ||||
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