WARRANT TO PURCHASE STOCK

Exhibit 4.6

THIS WARRANT AND THE SHARES ISSUABLE HEREUNDER HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”), OR THE SECURITIES LAWS OF ANY STATE AND, EXCEPT FOR AND PURSUANT TO THE PROVISIONS OF ARTICLE 5 BELOW, MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER SAID ACT AND APPLICABLE STATE SECURITIES LAWS OR, IN THE OPINION OF LEGAL COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR HYPOTHECATION IS EXEMPT FROM REGISTRATION.

WARRANT TO PURCHASE STOCK

Company: Somaxon Pharmaceuticals, Inc., a Delaware corporation
Number of Shares: 200,000, subject to adjustment
Class of Stock: Common Stock, $0.0001 par value per share
Warrant Price: As set forth below
Issue Date: March 11, 2009
Expiration Date: March 11, 2019

     THIS WARRANT CERTIFIES THAT, for good and valuable consideration, OXFORD FINANCE CORPORATION (together with any successor or permitted assignee or transferee of this Warrant or of any shares issued upon exercise hereof, “Holder”) is entitled to purchase the number of fully paid and non-assessable shares (the “Shares”) of the above-stated Class of Stock (the “Class”) of the above-named company (the “Company”) at the above-stated Warrant Price, all as set forth above and as adjusted pursuant to Article 2 of this Warrant, subject to the provisions and upon the terms and conditions set forth in this Warrant.

     A. (1) Warrant Issued in Lieu of Prepayment Fee . This Warrant is issued to Holder in connection with the Company’s prepayment in full of its obligations to Holder pursuant to, and in accordance with, Section 2.1.1(e) of the Loan Agreement, and in lieu of payment by the Company of the Prepayment Fee (as defined in the Loan Agreement), pursuant to the Payoff Letter among the Company, Silicon Valley Bank and Holder dated the date hereof, which Holder, by its acceptance hereof, and effective on Holder’s receipt of this executed Warrant and of payment in full of all such obligations in accordance with Section 2.1.1(e) of the Loan Agreement, hereby waives.

          (2) Warrant Price. The purchase price per Share hereunder (the “Warrant Price”) shall be equal to the closing price of a share of the Class as reported on the NASDAQ Global Market for March 11, 2009, subject to adjustment from time to time in accordance with the provisions of this Warrant.

ARTICLE 1. EXERCISE .

          1.1 Method of Exercise . Holder may exercise this Warrant by delivering the original of this Warrant together with a duly executed Notice of Exercise in substantially the form attached as Appendix 1 to the principal office of the Company. Unless Holder is exercising the conversion right set forth in Article 1.2, Holder shall also deliver to the Company a check, wire transfer (to an account designated by the Company), or other form of payment acceptable to the Company for the aggregate Warrant Price for the Shares being purchased.

          1.2 Conversion Right . In lieu of exercising this Warrant as specified in Article 1.1, Holder may from time to time convert this Warrant, in whole or in part, into a number of Shares determined by dividing (a) the aggregate fair market value of the Shares or other securities otherwise issuable upon exercise of this Warrant minus the aggregate Warrant Price of such Shares by (b) the fair market value of one Share. The fair market value of the Shares shall be determined pursuant to Article 1.3.

          1.3 Fair Market Value . If the Class is traded in a public market, the fair market value of a Share shall be the closing price of a share of common stock reported for the business day immediately before Holder delivers this Warrant together with its Notice of Exercise to the Company. If the Class is not traded in a public market, the Board of Directors of the Company shall determine fair market value in its reasonable good faith judgment.

          1.4 Delivery of Certificate and New Warrant . Promptly after Holder exercises or converts this Warrant and, if applicable, the Company receives payment of the aggregate Warrant Price, the Company shall deliver to Holder certificates for the Shares acquired and, if this Warrant has not been fully exercised or converted and has not expired, a new Warrant representing the Shares not so acquired.

          1.5 Replacement of Warrants . On receipt of evidence reasonably satisfactory to the Company of the loss, theft, destruction or mutilation of this Warrant and, in the case of loss, theft or destruction, on delivery of an indemnity agreement reasonably satisfactory in form and amount to the Company or, in the case of mutilation, on surrender and cancellation of this Warrant, the Company shall execute and deliver, in lieu of this Warrant, a new warrant of like tenor.

          1.6 Treatment of Warrant Upon Acquisition of Company .

               1.6.1 “ Acquisition ”. For the purpose of this Warrant, “Acquisition” means any sale, exclusive license, or other disposition of all or substantially all of the assets of the Company, or any reorganization, consolidation, merger or sale of outstanding capital stock of the Company where the holders of the Company’s outstanding voting securities before the transaction beneficially own less than a majority of the outstanding voting securities of the surviving entity or, if applicable, its parent entity, after the transaction.

               1.6.2 Treatment of Warrant at Acquisition .

A) Upon the written request of the Company, Holder agrees that, in the event of an Acquisition that is not a True Asset Sale (as defined below) in which the sole

consideration is cash, either (a) Holder shall exercise its conversion or purchase right under this Warrant and such exercise will be deemed effective immediately prior to the consummation of such Acquisition or (b) if Holder elects not to exercise the Warrant, this Warrant will expire upon the consummation of such Acquisition. The Company shall provide the Holder with written notice of its request relating to the foregoing (together with such reasonable information as the Holder may request in connection with such contemplated Acquisition giving rise to such notice), which is to be delivered to Holder not less than ten (10) days prior to the closing of the proposed Acquisition.

B) Upon the written request of the Company, Holder agrees that, in the event of an Acquisition that is an “arms length” sale of all or substantially all of the Company’s assets (and only its assets) to a third party that is not an Affiliate (as defined below) of the Company (a “True Asset Sale”), either (a) Holder shall exercise its conversion or purchase right under this Warrant and such exercise will be deemed effective immediately prior to the consummation of such Acquisition or (b) if Holder elects not to exercise the Warrant, this Warrant will continue until the Expiration Date if the Company continues as a going concern following the closing of any such True Asset Sale. The Company shall provide the Holder with written notice of its request relating to the foregoing (together with such reasonable information as the Holder may request in connection with such contemplated Acquisition giving rise to such notice), which is to be delivered to Holder not less than ten (10) days prior to the closing of the proposed Acquisition.

C) Upon the closing of any Acquisition other than those particularly described in subsections (A) and (B) above, the successor entity shall assume the obligations of this Warrant, and this Warrant shall be exercisable for the same securities, cash, and property as would be payable for the Shares issuable upon exercise of the unexercised portion of this Warrant as if such Shares were outstanding on the record date for the Acquisition and subsequent closing. The Warrant Price and/or number of Shares shall be adjusted accordingly.

D) Notwithstanding the foregoing provisions of this Section 1.6.2., in the event that the acquiror in an Acquisition does not agree to assume this Warrant at and as of the closing thereof, this Warrant, to the extent not exercised or converted on or prior to such closing, shall terminate and be of no further force or effect as of immediately following such closing if all of the following conditions are met: (i) the acquiror is subject to the reporting requirements of Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended, (ii) the class of stock or other security of the acquiror that would be received by Holder in connection with such Acquisition were Holder to exercise or convert this Warrant on or prior to the closing thereof is listed for trading on a national securities exchange or approved for quotation on an automated inter-dealer quotation system, and (iii) the value (determined as of the closing of such Acquisition in accordance with the definitive agreements therefor) of the acquiror stock and/or other securities that would be received by Holder in respect of each Share were Holder to exercise or convert this Warrant on or prior to the closing of such Acquisition is equal to or greater than three (3) times the then-effective Warrant Price.

As used in this Section 1.6, “ Affiliate ” shall mean any person or entity that owns or controls directly or indirectly ten percent (10%) or more of the stock of Company, any person or entity that controls or is controlled by or is under common control with such

persons or entities, and each of such person’s or entity’s officers, directors, joint venturers or partners, as applicable.

ARTICLE 2. ADJUSTMENTS TO THE SHARES .

          2.1 Stock Dividends, Splits, Etc . If the Company declares or pays a dividend on the outstanding shares of the Class payable in common stock or other securities, then upon exercise of this Warran