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INDEX TO FINANCIAL STATEMENTS

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

SONUS PHARMACEUTICALS, INC.
1522 217^th Place SE, Suite 100
Bothell, Washington 98021
Telephone: (425) 487-9500

                        , 2008

Dear Fellow Stockholder:

        The Board of Directors of Sonus Pharmaceuticals, Inc., a Delaware corporation, has approved an arrangement, which we refer to as the Arrangement, with OncoGenex Technologies Inc., a corporation organized pursuant to the Canada Business Corporations Act, or CBCA, pursuant to which Sonus will issue shares of its common stock in exchange for all of the outstanding securities of OncoGenex, resulting in OncoGenex becoming a wholly owned subsidiary of Sonus. The Board believes that the Arrangement will create a biopharmaceutical company with a strong oncology pipeline for a range of oncology indications with the resources to achieve near-term milestones. Your vote is very important and we ask for your support in approving the issuance of Sonus common stock in connection with the proposed Arrangement.

        On May 27, 2008, Sonus and OncoGenex entered into an Arrangement Agreement pursuant to which Sonus agreed to issue at closing that number of shares of its common stock equal to the number of its shares outstanding immediately prior to the closing of the Arrangement in exchange for all of the outstanding securities of OncoGenex. The Arrangement would cause the OncoGenex securityholders existing immediately prior to the closing to own 50% of the outstanding shares of Sonus common stock immediately following the closing. An additional 25,000,000 shares will be held in escrow and released to OncoGenex's securityholders upon the achievement of specified milestones. In addition, the Arrangement Agreement provides for the assumption by Sonus of all of the outstanding options to purchase OncoGenex common stock. Following the closing, Sonus stockholders will continue to own their existing Sonus common stock, which will not be affected by the Arrangement. Under the terms of the Arrangement Agreement, the proposed transactions would be consummated pursuant to a Plan of Arrangement under the CBCA which requires approval by OncoGenex securityholders and the Supreme Court of British Columbia, or the Court.

        Your vote is very important.    The Arrangement cannot be completed unless Sonus stockholders approve the issuance of Sonus common stock in connection with the Arrangement. Completion of the Arrangement is also subject to other customary conditions.

        We are holding an annual and special meeting of our stockholders, which we refer to as the Meeting, to vote on the proposals necessary to complete the Arrangement and certain other matters unrelated to the Arrangement. The Meeting will be held on                        , 2008, at                         a.m./p.m., Pacific time, at                                    . Notice of the Meeting and the related proxy statement are enclosed. More information about the Meeting, the Arrangement and the other business to be considered by Sonus stockholders is contained in this proxy statement. We encourage you to read this proxy statement carefully and in its entirety before voting.

        Whether or not you plan to attend the Meeting, please complete, date, sign and return, as promptly as possible, the enclosed proxy card in the accompanying reply envelope. Stockholders who attend the Meeting may revoke their proxies and vote in person.

        Our Board of Directors unanimously recommends that you vote "FOR" the proposal to approve the issuance of Sonus common stock in connection with the Arrangement and "FOR" the other proposals described in this proxy statement.

        We enthusiastically support the issuance of shares of Sonus common stock in connection with the Arrangement and join our Board of Directors in recommending that you vote in favor of the proposals described in this proxy statement.

        Neither the Securities and Exchange Commission nor any state, provincial or territorial securities regulatory agency or authority has approved or disapproved the Arrangement, passed upon the merits or fairness of the Arrangement or passed upon the adequacy or accuracy of the disclosure in this document. Any representation to the contrary is a criminal offense.

        This proxy statement is dated                        , 2008, and is first being mailed to stockholders on or about                        , 2008.

SONUS PHARMACEUTICALS, INC.
1522 217^th Place SE, Suite 100
Bothell, Washington 98021
Telephone: (425) 487-9500

NOTICE OF ANNUAL AND SPECIAL MEETING OF STOCKHOLDERS

        An Annual and Special Meeting of Stockholders of Sonus Pharmaceuticals, Inc., will be held at                                    on                                     ,                                     ,             , 2008 at                          a.m./p.m., Pacific Time, to consider and vote on the proposals listed below and to transact such other business as may properly come before the Meeting or any adjournment or postponement of the Meeting:

1.

Approval of Arrangement.    To approve the issuance of Sonus common stock in connection with the Arrangement Agreement, dated as of May 27, 2008, by and between Sonus and OncoGenex Technologies Inc., a corporation organized pursuant to the CBCA, a copy of which is included as Annex A to the proxy statement accompanying this notice, and the Plan of Arrangement relating to the Arrangement Agreement, a copy of which is included as Annex B to the proxy statement accompanying this notice;



2.

Election of Directors.    To elect the following five members of the Board of Directors of Sonus to serve until the 2009 annual meeting of stockholders or until their successors are elected and qualified:

3.

Approval of Name Change.    To approve an amendment to Sonus' Amended and Restated Certificate of Incorporation to change Sonus' name to "OncoGenex Pharmaceuticals, Inc." effective immediately upon completion of the Arrangement;



4.

Approval of Reverse Stock Split.    To approve an amendment to Sonus' Amended and Restated Certificate of Incorporation to (i) effect a reverse stock split of the outstanding shares of Sonus' common stock within the range of 1-for-10 to 1-for-20, the final ratio to be determined by Sonus' Board of Directors immediately prior to the closing of the Arrangement, and (ii) reduce the number of authorized shares of Sonus' common stock from 75,000,000 to the number of shares which is equal to two times the number of shares of our common stock outstanding immediately following the closing of the Arrangement and the reverse stock split;



5.

Ratification of Independent Auditors.    To ratify the appointment of Ernst & Young LLP as Sonus' independent registered public accounting firm for the fiscal year ending December 31, 2008;



6.

Adjournments.    To consider and act upon a proposal to approve, if necessary, an adjournment or postponement of the Meeting to solicit additional proxies; and



7.

Other Business.    To consider and act upon such other business and matters or proposals as may properly come before the Meeting or any adjournments or postponements thereof.

        The close of business on                                    , 2008 has been fixed as the record date for determining those Sonus stockholders entitled to vote at the Meeting. Accordingly, only stockholders of record at the close of business on that date will receive this notice of, and be eligible to vote at, the Meeting or any adjournments or postponements of the Meeting. Each of the items of business listed above is more fully described in the proxy statement that accompanies this notice.

        If Sonus stockholders wish to approve the Arrangement, they must approve Proposal No. 1 relating to the issuance of Sonus common stock to be made in connection with the Arrangement. The proposals to elect directors, to amend Sonus' Amended and Restated Certificate of Incorporation to effect the name change and the reverse stock split, and to ratify the appointment of Ernst & Young LLP as Sonus' independent registered public accounting firm are not dependent upon approval of the Arrangement. However, the proposal to amend Sonus' Amended and Restated Certificate of Incorporation to effect the name change will not be implemented unless the Arrangement is completed.

        Approval of the various proposals to be voted upon at the Meeting requires different votes:

•

The issuance of Sonus common stock in connection with the Arrangement and the ratification of Ernst & Young LLP as Sonus' independent registered public accounting firm require approval by the affirmative vote of a majority of the total number of votes cast on the particular proposal;



•

The election of five directors to Sonus' Board of Directors requires the affirmative vote of a plurality of votes cast by the holders of Sonus common stock; and



•

Approval of the amendments to Sonus' Restated Certificate of Incorporation to effect the name change and the reverse stock split requires the affirmative vote of a majority of the outstanding shares of Sonus common stock.

        As of the close of business on the record date for the Meeting, the directors and executive officers of Sonus collectively beneficially owned approximately 1,847,082 shares of Sonus common stock, inclusive of shares subject to stock options that may be exercised within 60 days following that date. Such shares represented approximately 4.78% of the total Sonus voting power as of such date.

        Your vote is very important.    Please read the proxy statement and the instructions on the enclosed proxy card and then, whether or not you expect to attend the Meeting in person, and no matter how many shares you own, please vote your shares as promptly as possible in accordance with the instructions on the enclosed proxy card. Submitting a proxy now will help assure a quorum and avoid added proxy solicitation costs. It will not prevent you from voting in person at the Meeting.

        The Board of Directors of Sonus unanimously recommends that you vote "FOR" the issuance of Sonus common stock in connection with the Arrangement, "FOR" the election of each of the director nominees, "FOR" the amendments to Sonus' Amended and Restated Certificate of Incorporation to effect the name change and the reverse stock split, and "FOR" the approval of the other proposals listed above and described in this proxy statement.

IMPORTANT NOTE

        In deciding how to vote on the matters described in this proxy statement, you should rely only on the information contained in this proxy statement and the annexes attached hereto. Neither Sonus nor OncoGenex has authorized any person to provide you with any information that is different from what is contained in this proxy statement.

        The information contained in this proxy statement speaks only as of the date indicated on the cover of this proxy statement unless the information specifically indicates that another date applies.

        If you have any questions about the matters described in this proxy statement, you may contact: Sonus Pharmaceuticals, Inc., 1522 217^th Place SE, Suite 100, Bothell, Washington, 98021, Telephone: (425) 487-9500, Attn: Chief Financial Officer.

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QUESTIONS AND ANSWERS ABOUT THE MEETING AND THE ARRANGEMENT

        The following are some of the questions that you may have as a stockholder of Sonus Pharmaceuticals, Inc. and brief answers to those questions. These questions and answers are not meant to be a substitute for the information contained in the remainder of this proxy statement, and this information is qualified in its entirety by the more detailed descriptions and explanations contained elsewhere in this proxy statement and the attached annexes. You are encouraged to read this proxy statement and the attached annexes carefully and in their entirety prior to making any decision relating to the proposals to be voted on at the Annual and Special Meeting of Stockholders, which we refer to as the Meeting. Throughout this proxy statement, Sonus Pharmaceuticals, Inc. is sometimes referred to as Sonus, we or us.

The Arrangement

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The Annual and Special Meeting of Stockholders; Voting Your Shares

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Additional Questions

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Sonus Pharmaceuticals, Inc.,
1522 217^th Place SE, Suite 100
Bothell, Washington, 98021
Telephone: (425) 487-9500
Attn: Chief Financial Officer

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SUMMARY

        This summary highlights selected information contained elsewhere in this proxy statement and may not contain all the information that is important to you. Sonus urges you to carefully read the remainder of this proxy statement and the attached annexes for a more complete understanding of the Arrangement and the other matters being considered at the Meeting. For more information, see the section entitled "Where You Can Find More Information" beginning on page 146 of this proxy statement. We have included page references to direct you to a more complete description of the topics presented in this summary.

THE COMPANIES

Sonus

Overview

        We are a biopharmaceutical company developing novel small molecule drugs for the treatment of patients with cancer. Our objective is to identify opportunities where there is the possibility for major improvements in patient treatments and where we believe we can mitigate development risk. We currently have one drug in clinical development. Our plan is to focus our efforts on development of this drug product and to evaluate in-licensing and out-licensing opportunities, as a means of achieving our business strategies and enhancing stockholder value.

Products

SN2310

        SN2310 Injectable Emulsion, or SN2310, is a novel camptothecin derivative. Camptothecins are an important class of anti-cancer drugs introduced in recent years; however, the marketed camptothecin analogs, irinotecan (Camptosar®) and topotecan (Hycamtin®), have limitations that may reduce their clinical utility. In the case of irinotecan, there is limited and variable conversion of the prodrug and unpredictable degree of toxicity whereas topotecan exhibits a short half-life. Irinotecan is used in the treatment of colorectal cancer, and topotecan is used in the treatment of lung, ovarian, and cervical cancers. SN2310 is a novel prodrug of SN-38 which is the active moiety of both SN2310 and irinotecan. Our objective with SN2310 is to provide a product that has enhanced anti-tumor activity and improved tolerability compared with the approved camptothecin-based products. An Investigational New Drug Application, or IND, was submitted to the U.S. Food and Drug Administration, or FDA, for SN2310 in June 2006 and Phase 1 clinical testing was initiated in September 2006. We expect to close enrollment in this study in 2008, and initiate a Phase 2 clinical trial in 2009.

TOCOSOL Paclitaxel

        TOCOSOL Paclitaxel is a novel formulation of paclitaxel manufactured in a ready-to-use, injectable vitamin E-based emulsion formulation. On September 24, 2007 we announced that TOCOSOL Paclitaxel failed to meet the primary endpoint in Phase 3 clinical testing. We have discontinued development of TOCOSOL Paclitaxel due to results of the Phase 3 study, and the time and cost that would be required to conduct the necessary clinical studies to continue development, which at a minimum, would include another Phase 3 pivotal trial. These closure activities were substantially complete by December 31, 2007.

Company Information

        Sonus Pharmaceuticals was incorporated in California in October 1991 and subsequently reorganized as a Delaware corporation in September 1995. Sonus' principal executive offices are located at 1522 217^th Place SE, Suite 100, Bothell, Washington 98021, and its telephone number is (425) 487-9500.

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OncoGenex

Overview

        OncoGenex is a biopharmaceutical company committed to the development and commercialization of new cancer therapies which focus on mechanisms of treatment resistance in cancer patients. OncoGenex product candidates address treatment resistance by blocking the production of specific proteins which it believes promote survival of tumor cells and are over-produced in response to a variety of cancer treatments. OncoGenex's aim in targeting these particular proteins is to disable the tumor cells' adaptive defenses and thereby render the tumor cells more susceptible to attack with a variety of cancer therapies, including chemotherapy, which OncoGenex believes will increase survival time and improve the quality of life for cancer patients.

        OncoGenex has two product candidates in clinical development and one product candidate in pre-clinical development.

Products

OGX-011 (custirsen sodium)

        OncoGenex is treating cancer patients in several clinical trials with OGX-011 to reduce clusterin production. Clusterin is a protein that is over-produced in several cancer types and in response to many cancer treatments, including hormone ablation therapy, chemotherapy and radiation therapy. Pre-clinical data suggest clusterin promotes cell survival. Increased clusterin production has been linked to faster rates of cancer progression, treatment resistance and shorter survival duration. Since increased clusterin production is observed in many human cancers, including prostate, non-small cell lung, breast, ovarian, bladder, renal, pancreatic, anaplastic large cell lymphoma, colon cancers and melanoma, OncoGenex believes that OGX-011 may have broad market potential to treat many cancer indications and disease stages.

        A broad range of pre-clinical studies conducted by the Prostate Centre at Vancouver General Hospital, which we refer to as the Prostate Centre, and others have shown that reducing clusterin production with OGX-011: (i) facilitates tumor cell death by sensitizing human prostate, non-small cell lung, breast, ovarian, bladder, renal and melanoma tumor cells to various chemotherapies; and (ii) sensitizes prostate tumor cells to hormone ablation therapy and sensitizes prostate and non-small cell lung tumor cells to radiation therapy. Pre-clinical studies conducted by the Prostate Centre also indicate that reducing clusterin production with OGX-011 re-sensitizes docetaxel-resistant prostate tumor cells to docetaxel.

        The Phase 1 clinical trials evaluated the safety, and established a recommended Phase 2 dose of OGX-011 in combination with docetaxel chemotherapy (two different schedules), gemcitabine and a platinum chemotherapy or hormone ablation therapy. In all the Phase 1 clinical trials, 640 mg, the highest dose evaluated, was well tolerated and established as the recommended Phase 2 dose.

        Five Phase 2 clinical trials have been conducted to evaluate the ability of OGX-011 to enhance the effects of therapy in prostate cancer, non-small cell lung cancer, or NSCLC, and breast cancer. Based on the Phase 2 results in over 300 patients, OncoGenex believes that both the hormone refractory prostate cancer, or HRPC, and NSCLC indications warrant development effort towards achieving marketing approval, although resources will initially be focused on the HRPC indication. Interim data are available from each of the five Phase 2 studies which demonstrate that adding OGX-011 to therapy shows potential benefits including:

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longer survival duration when adding OGX-011 to either mitoxantrone or docetaxel chemotherapy compared to survival duration observed in a 2007 clinical trial conducted by the British Columbia Cancer Agency and the TAX 327 study, a Phase 3 clinical trial evaluating

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docetaxel treatment compared to motoxantrone treatment as first-line chemotherapy in HRPC patients, in HRPC patients receiving either mitoxantrone or docetaxel as second-line chemotherapy;

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longer survival duration when adding OGX-011 to gemcitabine and a platinum-containing chemotherapy compared to the survival duration reported in prior published results from randomized clinical trials in NSCLC patients receiving gemcitabine and a platinum-containing chemotherapy;



•

early survival advantage when adding OGX-011 to first-line docetaxel chemotherapy compared to first-line docetaxel chemotherapy alone in patients with HRPC within a randomized Phase 2 trial;

        In addition to the encouraging interim survival data, HRPC patients receiving OGX-011 in combination with first-line chemotherapy had lower rates of disease progression and fewer treatment failures resulting in patients receiving an overall greater median number of chemotherapy treatment cycles and being maintained on chemotherapy longer than patients receiving chemotherapy alone. The interim data from OncoGenex's Phase 2 clinical trial in patients with HRPC receiving second-line chemotherapy showed evidence that adding OGX-011 to chemotherapy may have reversed docetaxel resistance. Reduction in pain with a median duration of 6 months was also observed in at least 46% of patients. In preliminary analyses, the average post-treatment serum clusterin levels were significantly lower compared to baseline levels before OGX-011 treatment and the average serum clusterin levels were predictive of survival with low serum clusterin levels correlating to longer survival. Low serum clusterin levels have also been shown to correlate with survival in OncoGenex's clinical trial in NSCLC.

        Based on data collected to date from OncoGenex's Phase 2 clinical trials, OncoGenex initially intends to perform a randomized clinical trial in patients with HRPC that will serve as a supportive registration trial in a New Drug Application, or NDA. OncoGenex intends to initiate this study in the first half of 2009. A second larger, randomized clinical trial, OncoGenex's primary registration trial, will be initiated following agreement on a Special Protocol Assessment with the FDA and when sufficient capital is available, which may be following completion of the randomized supportive registration trial, a subsequent financing, or upon establishing a development and marketing partnership. The USAN name for the OGX-011 drug product is custirsen sodium. Thus, in OncoGenex's registration trials OGX-011 will be referred to as custirsen sodium.

OGX-427

        OncoGenex's second product candidate, OGX-427, is designed to reduce production of heat shock protein 27, or Hsp 27. Hsp27 is a protein that is over-produced in response to many cancer treatments. Pre-clinical data suggest that Hsp 27 promotes cell survival. The development program for OGX-427 is focused on enhancing treatment sensitivity and delaying tumor progression in patients who have not fully developed treatment resistance and restoring treatment sensitivity in patients who have developed treatment resistance.

        OncoGenex is initially developing OGX-427 to enhance the effects of chemotherapy in a variety of cancers. OGX-427 is being evaluated in a Phase 1 clinical trial both as monotherapy, and in combination with chemotherapy. OncoGenex began treating patients in this clinical trial in July 2007 and expects results from the monotherapy evaluation of OGX-427 by the end of 2008.

        A number of pre-clinical studies conducted by the Prostate Centre and others have shown that inhibiting the production of Hsp27 in human prostate, breast, ovarian, pancreatic and bladder tumor cells sensitizes the cells to chemotherapy. Pre-clinical studies conducted by the Prostate Centre and others have shown that reducing Hsp27 production induced tumor cell death in prostate, breast, non-small cell lung, bladder and pancreatic cancers. The Prostate Centre has also conducted pre-clinical

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studies that indicate that reducing Hsp27 production sensitizes prostate tumor cells to hormone ablation therapy.

        The Phase 1 study of OGX-427 is in the dose escalation phase. To date, there has not been dose-limiting toxicity defining the maximum tolerated dose. Once a maximum tolerated dose for OGX-427 as a monotherapy has been determined per protocol, OGX-427 in combination with docetaxel will be evaluated.

OGX-225

        OncoGenex's third product candidate, OGX-225, is designed to reduce production of both insulin-like growth factor binding protein-2, or IGFBP-2, and insulin-like growth factor binding protein-5, or IGFBP-5, with a single product. Increased IGFBP-2 or IGFBP-5 production is observed in many human cancers and is linked to faster rates of cancer progression, treatment resistance and shorter survival duration. OncoGenex believes employing OGX-225 as a single product to simultaneously inhibit the production of both IGFBP-2 and IGFBP-5 has the potential to delay disease progression in cancers dependent upon insulin-like growth factor-1, or IGF-1. OncoGenex has completed pre-clinical proof of concept studies with OGX-225.

        Since IGFBP-2 and IGFBP-5 are over-expressed in a variety of cancers, OGX-225 may have broad market potential to treat many cancer indications. OncoGenex believes that the initial opportunity for OGX-225 would be in breast and prostate cancer patients early in the course of their recurrence after failed hormone ablation therapy.

        OncoGenex has identified the lead compound and has completed numerous pre-clinical proof of concept studies with OGX-225 indicating that it delays progression to hormone independence in prostate and breast cancer model systems. OncoGenex has not defined when it will initiate the pre-clinical studies required for a regulatory submission and initiation of Phase 1 clinical trials.

Company Information

        OncoGenex Technologies Inc. was incorporated in Canada in 2000. OncoGenex's principal executive offices are located at 400 - 1001 West Broadway, Vancouver, British Columbia, V6H 4B1, and its telephone number is (604) 736-3678.

THE ARRANGEMENT

Overview of the Arrangement

        The Board has unanimously approved the terms of an Arrangement Agreement, dated as of May 27, 2008, by and between Sonus and OncoGenex, pursuant to which we will issue shares of our common stock in exchange for all of the outstanding securities of OncoGenex, including common stock, preferred stock and convertible debentures. The result of the transaction will be to cause OncoGenex to become a wholly owned subsidiary of Sonus. We will continue to exist as the parent entity of OncoGenex and will continue to be publicly traded. The Board has also unanimously approved the Plan of Arrangement relating to the Arrangement Agreement. In accordance with the CBCA, the Plan of Arrangement must be approved by OncoGenex securityholders and the Supreme Court of British Columbia, or the Court, prior to effectiveness of the transactions contemplated by the Arrangement Agreement. We have included the Arrangement Agreement as Annex A to this proxy statement, and we have included the Plan of Arrangement as Annex B to this proxy statement. We encourage you to read the entire Arrangement Agreement and Plan of Arrangement carefully as they are the legal documents governing the Arrangement.

        If our stockholders approve the issuance of our common stock in connection with the Arrangement, we expect to complete the Arrangement shortly after the Meeting. However, the

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Arrangement is also subject to the satisfaction or waiver of certain other conditions, including the approval of the OncoGenex securityholders. Accordingly, we cannot assure you when or if the Arrangement will be completed.

Reasons for the Arrangement

        The Board has unanimously approved the Arrangement because it believes that the Arrangement will result in a biopharmaceutical company with the following potential advantages:

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Pipeline.  The combined company will have a strong oncology pipeline addressing distinct unmet needs in the treatment of cancer, with three candidates in various stages of clinical development and an additional product in preclinical development;



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Markets.  The drug candidates in the combined company's pipeline address a range of oncology indications. The patient populations targeted by these clinical and preclinical stage product candidates are large, and their needs are either underserved by existing, approved products or existing, approved products do not fully meet their medical needs. The product candidates may address these unmet needs in large markets;



•

Financial Resources.  The financial resources of the combined company will position it to focus on execution of near-term milestones and further development of the combined product pipeline; and



•

Human Resources and Capabilities.  The combined company will be led by a capable management team and have the preclinical, clinical and regulatory development capabilities in place necessary to design and implement the required programs to demonstrate the benefits of the various drug candidates and progress those candidates through the various stages of regulatory development.

Opinion of Our Financial Advisor

        In connection with the Arrangement, the Board received an opinion from our financial advisor, Leerink Swann LLC, as to the fairness, from a financial point of view and as of the date of such opinion, to our stockholders of the consideration to be paid by us in connection with the Arrangement. The full text of Leerink's written opinion is attached to this proxy statement as Annex C. Holders of our common stock are encouraged to read this opinion carefully and in its entirety for a description of the assumptions made, procedures followed, matters considered and limitations on the review undertaken. Leerink's opinion was provided to the Board in its evaluation of the consideration to be paid in connection with the Arrangement from a financial point of view, does not address any other aspect of the Arrangement and does not constitute a recommendation to any our stockholder as to how to vote or act with respect to the Arrangement.

Recommendations of the Board of Directors

        After careful consideration, including the assessment of a number of strategic alternatives, the Board unanimously approved the Arrangement and the issuance of our common stock to be issued in connection with the Arrangement. The Board determined that the Arrangement and the transactions contemplated thereby are fair to, and in the best interests of, Sonus and its stockholders. Accordingly, the Board unanimously recommends that you vote "FOR" the proposal to issue our common stock in connection with the Arrangement.

Additional Interests of Sonus Directors and Executive Officers in the Arrangement

        Certain of our executive officers and directors may have interests in the completion of the Arrangement that are different from, or in addition to, their interests as our stockholders generally. In

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particular, Michael A. Martino, our President, Chief Executive Officer and a member of our Board, and Alan Fuhrman, our Senior Vice President and Chief Financial Officer, are parties to severance/change in control agreements that are triggered upon a termination of employment in specified circumstances. Mr. Martino and Mr. Fuhrman will be terminated upon completion of the Arrangement. The estimated severance payments that would be made in connection with such terminations are: Mr. Martino—$1,150,501; and Mr. Fuhrman—$273,249.

Directors and Management of Sonus Following the Arrangement

        Assuming that each of the director nominees referenced in the section entitled "Proposal No. 2—Election of Directors" beginning on page 115 of this proxy statement is approved by our stockholders at the Meeting, our Board will be comprised of the following persons immediately following the Meeting: Michael A. Martino, Michelle G. Burris, George W. Dunbar, Jr., Robert E. Ivy and Dwight Winstead. In the event the Arrangement is completed, the Board has approved modifications to the composition of the Board such that immediately upon completion of the Arrangement:

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the number of directors that shall serve on the Board shall be increased from five to seven in accordance with our bylaws;



•

two members of the Board shall resign from the Board resulting in an aggregate of four vacancies;



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three of the vacancies shall be filled by current directors of OncoGenex, or nominees of OncoGenex, who shall be selected by OncoGenex prior to completion of the Arrangement; and



•

the remaining vacancy shall be filled by an independent director to be selected by the remaining three Sonus directors and the three nominated OncoGenex directors.

        As of the date of the Meeting, we expect to have two executive officers: Michael A. Martino, our President and Chief Executive Officer, and Alan Fuhrman, our Senior Vice President and Chief Financial Officer. In the event the Arrangement is completed, Mr. Martino and Mr. Fuhrman will be terminated and will be replaced by Scott Cormack, who will serve as our President and Chief Executive Officer, and Steve Anderson, who will serve as our Chief Financial Officer.

Material United States Federal Income Tax Consequences

        Our stockholders will not exchange their Sonus common stock in the Arrangement and accordingly will not recognize any taxable gain or loss as a result of the Arrangement. However, we strongly urge you to consult with a tax advisor to determine the particular U.S. federal, state, local or foreign income or other tax consequences of the Arrangement to you.

Accounting Treatment of the Arrangement

        Upon completion of the Arrangement, OncoGenex securityholders will hold approximately 50% of the outstanding shares of the combined company (or up to 62.6% if certain milestones are reached) and both OncoGenex and Sonus will have equal representation on the Board of Directors of the combined company. Because OncoGenex senior management will comprise the majority of senior management positions of the combined company and because OncoGenex shareholders are expected to hold more than 50% of the combined company upon achievement of certain milestones, it is anticipated that the transaction will be treated as a reverse merger under the purchase method of accounting in accordance with U.S. generally accepted accounting principles, with OncoGenex being identified as the acquiring entity. This means that OncoGenex will allocate the purchase price, including the costs of the acquisition, to the fair value of our tangible and intangible assets and liabilities as of the effective date of the Arrangement. Our assets and liabilities and results of

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operations will be consolidated into the results of operations of OncoGenex as of and from the effective date of the Arrangement.

Regulatory Matters Related to the Arrangement

        Other than approval of the Arrangement by the Court and the filing of this proxy statement with the U. S. Securities and Exchange Commission, or SEC, Sonus and OncoGenex are not aware of any material governmental or regulatory requirements that must be complied with regarding the Arrangement.

Dissenters'/Appraisal Rights for Sonus Stockholders

        Our stockholders are not entitled to dissenters' or appraisal rights under Delaware law in connection with the Arrangement.

Listing of Sonus Common Stock

        Our common stock is currently traded on the Nasdaq Global Market under the symbol "SNUS." Pursuant to the terms of the Arrangement Agreement, we are required to use our best efforts to maintain the listing of our common stock on the Nasdaq Global Market or the Nasdaq Capital Market and to cause our common stock, including the shares of our common stock to be issued in connection with the Arrangement, to be listed and traded on the Nasdaq Global Market or the Nasdaq Capital Market. We may also apply for listing on the Toronto Stock Exchange, if requested by OncoGenex.

ARRANGEMENT AGREEMENT AND PLAN OF ARRANGEMENT

Plan of Arrangement and Court Approval

        The Arrangement of OncoGenex under the CBCA requires approval by both the Court and the OncoGenex securityholders. Prior to the mailing of this proxy statement, OncoGenex expects to obtain an interim order of the Court providing for the holding of an OncoGenex special meeting to approve the Arrangement. Subject to approval by the OncoGenex securityholders at the meeting, a hearing in respect of a final order will be scheduled. At the hearing, the Court will consider, among other things, the fairness of the Arrangement. The Arrangement will be effective upon filing the Articles of Arrangement pursuant to the provisions of the CBCA after obtaining a final order from the Court approving the Arrangement.

Arrangement Consideration

        Upon completion of the Arrangement, we will issue to the securityholders of OncoGenex a number of shares of our common stock equal to the number of shares of our common stock outstanding immediately prior to the closing, which we refer to as the non-contingent shares. Accordingly, immediately after the closing of the Arrangement, our stockholders and the former OncoGenex securityholders will each collectively own 50% of the outstanding shares of our common stock. The non-contingent shares will be allocated among the OncoGenex securityholders outstanding as of the date of closing, including holders of common stock, preferred stock and convertible debentures. The formula for determining the allocation of our common stock as between the various OncoGenex securityholders is set forth in the Arrangement Agreement.

        In addition to the non-contingent shares, the holders of OncoGenex capital stock are also entitled to receive up to an aggregate of 25,000,000 additional shares of our common stock upon the achievement of specified milestones relating to OncoGenex product candidates and the future price of Sonus' common stock, which we refer to as milestone shares. Assuming these milestone shares are earned in full and no other shares of our common stock are issued after completion of the

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Arrangement, the OncoGenex securityholders existing immediately prior to closing would own 62.6% of the outstanding shares of our common stock following the release of the milestone shares. Until such time as the milestone shares are earned, they will be deposited into an escrow account and will be voted in proportion to all other votes cast at a stockholder meeting, such that the milestone shares will not affect the outcome of a vote on any matter submitted to stockholders while they are held in escrow. The details surrounding the milestone shares are set forth in the escrow agreements to be executed prior to the closing of the Arrangement, a form of which is included as Annex E to this proxy statement.

        In the event we effect the reverse stock split as described in Proposal No. 4, the number of shares of our common stock issued pursuant to the Arrangement, including the milestone shares, will be reduced in proportion to the ratio of the reverse stock split on the same basis as any other outstanding shares of our common stock.

Stock Options

        Options to purchase shares of our common stock under the Sonus 2007 Stock Performance Incentive Plan will be subject to accelerated vesting in accordance with the terms of such plan and will remain outstanding. Options to purchase shares of our common stock under the 1991 Incentive Stock Option, Nonqualified Stock Option and Restricted Stock Purchase Plan will also remain outstanding, but will not be subject to accelerated vesting. All other outstanding options to purchase our common stock will terminate.

        Each option to purchase shares of OncoGenex common stock will be assumed by us and will be exercisable by its holder for shares of our common stock, as adjusted to reflect the terms of the Arrangement.

Other Material Provisions of the Arrangement Agreement

Representations and Warranties (Page 76)

        Each of OncoGenex and Sonus made customary representations and warranties in the Arrangement Agreement. These representations and warranties relate to, among other things:

•

corporate organization, qualification to do business and good standing;



•

capital structure;



•

corporate authority to enter into the Arrangement Agreement and to consummate the transactions contemplated thereby;



•

accuracy of financial statements;



•

absence of undisclosed liabilities;



•

absence of any litigation, claims, investigations or other actions against OncoGenex;



•

compliance with applicable laws; and



•

approval of the Arrangement Agreement and the transactions contemplated thereby.

Covenants and Agreements (Page 78)

        Each of OncoGenex and Sonus agreed through the Arrangement Agreement that they will, among other things:

•

carry on their business in the ordinary course consistent with past practice, including not making any substantial or unusual capital expenditures or expansion of its business facilities;

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•

not amend or change their articles or by-laws, except as contemplated by the Arrangement Agreement;



•

not reorganize or merge with any other person or entity, nor acquire or agree to acquire the business of any other person or entity, except as contemplated by the Arrangement Agreement;



•

use all reasonable efforts to obtain the required approvals of their respective securityholders for the transactions contemplated by the Arrangement Agreement; and



•

use all reasonable efforts to ensure that the representations and warranties given by it in connection with the Arrangement Agreement are true and correct in all material respects on and as of the effective date of the Arrangement.

        In addition, OncoGenex and Sonus have each agreed that, except as contemplated by the Arrangement Agreement, they shall not solicit, participate in discussions regarding, or enter into any agreement regarding, any acquisition proposal, as such term is defined in the Arrangement Agreement.

Conditions to Completion of the Arrangement (Page 81)

        The respective obligations of Sonus and OncoGenex to complete the transactions contemplated by the Arrangement Agreement shall be subject to, among others things, the satisfaction of the following conditions:

•

the Arrangement shall have been approved at the meeting of the OncoGenex securityholders by the requisite number of votes of each class and series of outstanding security;



•

the issuance of shares of our common stock in connection with the Arrangement shall have been approved at the Meeting in accordance with Delaware law and Sonus' Amended and Restated Certificate of Incorporation and bylaws;



•

the shares of our common stock issuable in connection with the Arrangement shall have been authorized for listing on any stock exchange or trading market on which shares of Sonus common stock are then listed for trading;



•

this proxy statement shall have been approved by the SEC under the Securities Exchange Act prior to mailing;



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the amendment to our Amended and Restated Certificate of Incorporation to change our name shall have been effected, unless waived by OncoGenex securityholders in accordance with the Arrangement Agreement;



•

the amendment to our Amended and Restated Certificate of Incorporation to effect the reverse stock split of the authorized and outstanding shares of our common stock shall have been effected, unless waived by OncoGenex securityholders in accordance with the Arrangement Agreement;



•

the issuance of our common stock in connection with the Arrangement shall be exempt from registration pursuant to Section 3(a)(10) of the Securities Act;



•

we shall have taken steps to ensure that the our common stock to be issued in connection with the Arrangement may be resold under applicable Canadian securities laws;



•

between the execution date of the Arrangement Agreement and the completion date of the Arrangement, there shall not have occurred a material adverse change (as defined in the Arrangement Agreement) to OncoGenex or us, as applicable;



•

holders of more than 2% of the issued and outstanding shares of OncoGenex capital stock shall not have exercised dissenters' rights in respect of the Arrangement;

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•

each of the voting agreements executed by certain officers, directors and principal stockholders of Sonus and OncoGenex shall be and remain in full force and effect; and



•

the receipt by us of written resignations of our directors such that three (3) of our directors remain and the Board shall have appointed specified directors to fill the vacancies.

Termination of the Arrangement (Page 83)

        The Arrangement Agreement may be terminated and the Arrangement abandoned at any time prior to the closing of the Arrangement:

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by the mutual written consent of OncoGenex and Sonus;



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by either OncoGenex or Sonus;



•

if there is any injunction or other court order issued that would prevent completion of the Arrangement,



•

if the Arrangement is not completed by September 30, 2008, except as set forth in the Arrangement Agreement;



•

if the approval of Sonus stockholders is not obtained at the our stockholder meeting, except as set forth in the Arrangement Agreement; or



•

if the approval of OncoGenex securityholders is not obtained at the OncoGenex securityholders' meetings, except as set forth in the Arrangement Agreement.



•

by Sonus:



•

upon a breach of any covenant, agreement, representation or warranty by OncoGenex, if such breach would result in a failure to satisfy any condition to Sonus' obligation to closing;



•

if the Sonus Board recommends an alternative acquisition proposal after determining that such alternative acquisition proposal constitutes a superior proposal;



•

if there shall have occurred one or more events which have caused a material adverse effect, as defined in the Arrangement Agreement, on OncoGenex; or



•

if the working capital of OncoGenex on the day immediately prior to the proposed closing date is negative.



•

by OncoGenex:



•

upon a breach of any covenant, agreement, representation or warranty by Sonus, if such breach would result in a failure to satisfy any condition to OncoGenex's obligation to closing;



•

if the Sonus Board withdraws or modifies its recommendation to approve the issuance of shares in connection with the Arrangement, recommends an alternative acquisition proposal, or fails to recommend against accepting any tender offer made for 20% or more of the outstanding shares of Sonus common stock;



•

if there shall have occurred one or more events which have caused a material adverse effect (as defined in the Arrangement Agreement) on Sonus; or



•

if the working capital of Sonus on the day immediately prior to the proposed closing date is below a specified amount as set forth in the Arrangement Agreement.

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Termination Fees and Expenses (Page 84)

        We will be required to pay OncoGenex a termination fee in the amount of $500,000, and will be required to reimburse OncoGenex for out-of-pocket expenses not to exceed $350,000, if the Arrangement Agreement is terminated for either of the following reasons:

•

if OncoGenex terminates the Arrangement Agreement because our Board withdraws or modifies its recommendation to approve the issuance of shares in connection with the Arrangement, recommends an alternative acquisition proposal, or fails to recommend against accepting any tender offer made for 20% or more of the outstanding shares of our common stock; or



•

if we terminate the Arrangement Agreement because our Board recommends an alternative acquisition proposal after determining that such alternative acquisition proposal constitutes a superior proposal.

        Except as stated above, all costs and expenses incurred be each party will be the responsibility of the party incurring such expenses.

RELATED AGREEMENTS

OncoGenex Voting Agreements

        We have entered into voting agreements with certain OncoGenex securityholders in connection with the proposed Arrangement. Such voting agreements represent approximately 82% of the outstanding shares of common stock of OncoGenex, at least 67% of each series of the outstanding shares of preferred stock of OncoGenex, and approximately 96% of the outstanding principal amount of convertible debentures of OncoGenex. Pursuant to and during the terms of the voting agreements, each OncoGenex securityholder that has entered into a voting agreement with us has agreed to vote, or cause to be voted, all of the OncoGenex securities owned by such securityholder in favor of, among other things, the approval of the Arrangement and the transactions contemplated thereby.

Sonus Voting Agreements

        OncoGenex has entered into voting agreements with our executive officers and directors in connection with the proposed Arrangement. Pursuant to and during the terms of the voting agreements, each Sonus executive officer and director that has entered into a voting agreement with OncoGenex has agreed to vote, or cause to be voted, all of the Sonus common stock owned by such executive officer and director in favor of, among other things, the approval of the issuance of our common stock to be issued in connection with the Arrangement.

Escrow Agreement

        Under the terms of escrow agreements to be executed upon the closing of the Arrangement, the holders of OncoGenex capital stock will be entitled to receive up to an aggregate of 25,000,000 shares of our common stock in addition to the non-contingent shares issued at closing. The additional shares, or milestone shares, will be deposited by us into escrow accounts and will be released upon achievement of various milestones relating to OncoGenex product candidates and the future price of our common stock, as detailed in the escrow agreements. If the milestone shares are not earned within 6 years after the closing of the Arrangement, they will be returned to us for cancellation.

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THE ANNUAL AND SPECIAL MEETING

The Sonus Annual and Special Meeting

        The Meeting will be held on                        , 2008, at                         a.m./p.m., Pacific time, at                                    . At the Meeting, our stockholders will be asked:

1.

To approve the issuance of our common stock proposed to be made in connection with the Arrangement;

2.

To elect the following five members of the Board to serve until our 2009 annual meeting of stockholders or until their successors are elected and qualified;

3.

To approve an amendment to our Amended and Restated Certificate of Incorporation to change our name to "OncoGenex Pharmaceuticals, Inc." effective immediately following completion of the Arrangement;

4.

To approve an amendment to our Amended and Restated Certificate of Incorporation to: (i) effect a reverse stock split of the outstanding shares of our common stock within the range of 1-for-10 and 1-for-20, the final ratio to be determined by the Board immediately prior to completion of the Arrangement and (ii) reduce the number of authorized shares of our common stock from 75,000,000 to the number of shares which is equal to two times the number of shares of our common stock outstanding immediately following closing of the Arrangement and the reverse stock split;

5.

To ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2008;

6.

To consider and act upon a proposal to approve, if necessary, an adjournment or postponement of the Meeting to solicit additional proxies; and

7.

To consider and act upon such other business and matters or proposals as may properly come before the Meeting or any adjournments or postponements thereof.

        The approval of the issuance of our common stock in connection with the Arrangement is a condition to the completion of the Arrangement. Accordingly, if our stockholders wish to approve the Arrangement, they must approve this proposal.

        The close of business on                        , 2008 has been fixed as the record date for determining those Sonus stockholders entitled to vote at the Meeting. Accordingly, only stockholders of record at the close of business on that date will receive this notice of, and be eligible to vote at, the Meeting or any adjournments or postponements of the Meeting. Each of the items of business listed above is more fully described in this proxy statement.

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SELECTED HISTORICAL CONDENSED FINANCIAL DATA OF SONUS

        The following information is being provided to aid in your analysis of the financial aspects of the Arrangement. We derived our financial information from audited financial statements for fiscal years 2003 through 2007, and from unaudited financial statements for the three months ended March 31, 2008 and 2007.

        In the opinion of our management, the unaudited interim period information reflects all adjustments, consisting only of normal and recurring adjustments, necessary for a fair presentation of the results of operations and financial condition for the three months ended March 31, 2008 and 2007. Results for interim periods should not be considered indicative of results for any other period or for the year. The following information is only a summary. You should read it along with our historical audited financial statements for the period ended December 31, 2007 and the unaudited financial statements for the three months ended March 31, 2008 and 2007 and related notes attached to this proxy statement and the section entitled "Management's Discussion and Analysis of Financial Condition and Results of Operations of Sonus" beginning on page 32 of this proxy statement.

Statements of Operations

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SELECTED HISTORICAL CONDENSED CONSOLIDATED FINANCIAL DATA OF ONCOGENEX

        The following information is being provided to aid in your analysis of the financial aspects of the Arrangement. OncoGenex derived its financial information from audited financial statements for fiscal years 2003 through 2007 and from unaudited financial statements for the three months ended March 31, 2008 and 2007.

        In the opinion of our management, this unaudited interim period information reflects all adjustments, consisting only of normal and recurring adjustments, necessary for a fair presentation of the results of operations and financial condition for the three months ended March 31, 2008 and 2007. Results for interim periods should not be considered indicative of results for any other period or for the year. The following information is only a summary. You should read it along with our historical audited financial statements for the period ended December 31, 2007 and the unaudited financial statements for the three months ended March 31, 2008 and 2007 and related notes attached to this proxy statement and the section entitled "OncoGenex Management's Discussion and Analysis of Financial Condition and Results of Operations of OncoGenex" beginning on page 39 of this proxy statement.

Consolidated Statement of Operations

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UNAUDITED PRO FORMA COMBINED CONDENSED CONSOLIDATED FINANCIAL INFORMATION

        The accompanying unaudited pro forma combined condensed consolidated financial statements present financial information from Sonus and OncoGenex unaudited pro forma combined condensed consolidated statements of operations for the three months ended March 31, 2008 and for the twelve months ended December 31, 2007, and the unaudited pro forma combined condensed consolidated balance sheet as of March 31, 2008 based on the unaudited historical balance sheets of Sonus and OncoGenex as of that date. The unaudited pro forma combined condensed consolidated statement of operations is presented as if the Arrangement had occurred on the first day of the period (i.e., January 1, 2007). The unaudited pro forma combined condensed consolidated balance sheet gives effect to the transaction as if it occurred on March 31, 2008. The unaudited pro forma combined condensed consolidated financial data are based on estimates and assumptions, which are preliminary and subject to change, as set forth in the notes to such statements and which are provided for informational purposes only. The unaudited pro forma combined condensed consolidated financial data are not necessarily indicative of the financial position or operating results that would have been achieved had the Arrangement been consummated as of the dates indicated, nor are they necessarily indicative of future financial position or operating results. This information should be read in conjunction with the historical financial statements and related notes of Sonus and OncoGenex included in this proxy statement.

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UNAUDITED PRO FORMA COMBINED CONDENSED CONSOLIDATED BALANCE SHEET

(Amounts in thousands)