Exhibit 10.36

SECURITIES PURCHASE AGREEMENT

This SECURITIES PURCHASE AGREEMENT (this “Agreement”), dated as of October 17, 2005 is made by and among Sonus Pharmaceuticals, Inc., a Delaware corporation, with headquarters located at 22026 20th Avenue S.E., Bothell, Washington 98021 (the “Company”), and Schering AG, a German corporation (“Schering AG”), and Schering Berlin Venture Corporation, a Delaware corporation (“SBVC”, and collectively with Schering AG, the “Investor”).

RECITALS:

A.            The Company and Investor are executing and delivering this Agreement in reliance upon the exemption from securities registration afforded by Section 4(2) of the Securities Act and Rule 506 under Regulation D.

B.            The Investor desires, upon the terms and conditions stated in this Agreement, to purchase 3,900,000 shares of the Company’s Common Stock (the “Common Shares”) and a warrant in the form of Exhibit A hereto, to purchase 975,000 shares of the Company’s Common Stock (the “Warrant” and collectively with the Common Shares, the “Securities”) for an aggregate purchase price of Fifteen Million Seven Hundred Ninety Nine Thousand Eight Hundred Seventy-Five Dollars ($15,799,875).  The purchase price per share of the Common Shares is $4.02, which is equal to the per share closing sale price as reported on Nasdaq for the trading day immediately preceding the date of this Agreement, or, if this Agreement is entered into after 4:00 p.m. Eastern Standard Time, the day of this Agreement.  The purchase price for the Warrant is $.125 multiplied by the number of shares of Common Stock exercisable under the Warrant (the “Warrant Shares”).

C.            Contemporaneously with the execution and delivery of this Agreement, the parties hereto are executing and delivering a Registration Rights Agreement under which the Company has agreed to provide certain registration rights under the Securities Act, the rules and regulations promulgated thereunder and applicable state securities laws.

D.            The capitalized terms used herein and not otherwise defined have the meanings given them in Article IX hereof.

In consideration of the premises and the mutual covenants contained herein and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Company and Investor hereby agrees as follows:

ARTICLE I
PURCHASE AND SALE OF SECURITIES

1.1           Purchase and Sale of Securities.  On the Closing Date, subject to the terms of this Agreement and the satisfaction or waiver of the conditions set forth in Articles VI and VII hereof, the Company will issue and sell to (A) SBVC, and SBVC will purchase directly from the Company, 3,900,000 Common Shares, to be registered in the name of SBVC, and (B) Schering AG, and Schering AG will purchase directly from the Company, the Warrant, to be registered in the name of Schering AG.

1.2           Payment.  At the Closing, Investor will pay the purchase price for the Securities, by wire transfer of immediately available funds in accordance with the wire instructions set forth on

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Exhibit B hereto.  The Company shall deliver to Investor a certificate representing the Common Shares and a certificate representing the Warrant so purchased by Investor on the Closing Date against delivery of the purchase price as described above.

1.3           Closing Date.  Subject to the satisfaction or waiver of the conditions set forth in Articles VI and VII hereof, the Closing will take place at 8 a.m. Pacific Standard Time on October 17, 2005, or at such other date or time agreed upon by the parties to this Agreement (the “Closing Date”).  The Closing will be held at the offices of Stradling Yocca Carlson & Rauth or at such other place as the parties agree.

ARTICLE II
INVESTOR’S REPRESENTATIONS AND WARRANTIES

Investor represents and warrants to the Company that:

2.1           Investment Purpose.  Investor is purchasing Securities for its own account and not with a present view toward the public sale or distribution thereof, except pursuant to sales registered or exempted from registration under the Securities Act, provided, however, that by making the representation herein, the Investor does not agree to hold any of the Securities for any minimum or other specific term and reserves the right to dispose of the Securities at any time in accordance with or pursuant to a registration statement or an exemption from registration under the Securities Act, subject to the restrictions on transfer set forth in the Registration Rights Agreement.

2.2           Accredited Investor.  Investor is an “accredited investor” as such term is defined in Regulation D promulgated under the Securities Act.

2.3           Reliance on Exemptions.  Investor understands that the Securities are being offered and sold to it in reliance upon specific exemptions from the registration requirements of United States federal and state securities laws and that the Company is relying upon the truth and accuracy of, and Investor’s compliance with, the representations, warranties, agreements, acknowledgments and understandings of Investor set forth herein in order to determine the availability of such exemptions and the eligibility of Investor to acquire the Securities.

2.4           Information.  Investor has received and read the SEC Documents.  Investor and its advisors, if any, have been furnished with all materials relating to the business, finances and operations of the Company, and materials relating to the offer and sale of the Securities, that have been requested by Investor or its advisors, if any.  Investor and its advisors, if any, have been afforded the opportunity to ask questions of the Company.  Neither such inquiries nor any other due diligence investigation conducted by Investor or any of its advisors or representatives modify, amend or affect Investor’s right to rely on the Company’s representations and warranties contained in Article III below.  Investor acknowledges and understands that its investment in the Securities involves a significant degree of risk, including the risks reflected in the SEC Documents.

2.5           Governmental Review.  Investor understands that no United States federal or state agency or any other government or governmental agency has passed upon or made any recommendation or endorsement of the Securities or an investment therein.

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2.6           Transfer or Resale.  Investor understands that:

(a)           except as provided in the Registration Rights Agreement, the Securities have not been and are not being registered under the Securities Act or any applicable state securities laws and, consequently, Investor will not be afforded the protection of Section 11 of the Securities Act, and Investor may have to bear the risk of owning the Securities for an indefinite period of time because the Securities may not be transferred unless (i) the resale of the Securities is registered pursuant to an effective registration statement under the Securities Act; (ii) Investor has delivered to the Company an opinion of counsel (in form, substance and scope customary for opinions of counsel in comparable transactions) to the effect that the Securities to be sold or transferred may be sold or transferred pursuant to an exemption from such registration; (iii) the Securities are sold or transferred pursuant to Rule 144; or (iv) the Securities are sold or transferred to an affiliate (as defined in Rule 144) of Investor;

(b)           any sale of the Securities made in reliance on Rule 144 may be made only in accordance with the terms of Rule 144 and, if Rule 144 is not applicable, any resale of the Securities under circumstances in which the seller (or the person through whom the sale is made) may be deemed to be an underwriter (as that term is defined in the Securities Act) may require compliance with some other exemption under the Securities Act or the rules and regulations of the SEC thereunder; and

(c)           except as set forth in the Registration Rights Agreement, neither the Company nor any other person is under any obligation to register the Securities under the Securities Act or any state securities laws or to comply with the terms and conditions of any exemption thereunder.

2.7           Legends.  Investor understands that until (a) the Securities may be sold by Investor under Rule 144(k) or (b) such time as the resale of the Securities has been registered under the Securities Act as contemplated by the Registration Rights Agreement, the certificates representing the Securities will bear a restrictive legend in substantially the following form (and a stop-transfer order may be placed against transfer of the certificates for such Securities):

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES.  THE SECURITIES MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER APPLICABLE SECURITIES LAWS, OR UNLESS OFFERED, SOLD OR TRANSFERRED PURSUANT TO AN AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THOSE LAWS.

The legend set forth above will be removed and the Company will issue a certificate without the legend to the holder of any certificate upon which it is stamped, in accordance with the terms of Article V hereof.

2.8           Authorization; Enforcement.  This Agreement, the Registration Rights Agreement and the Warrant have been duly and validly authorized, executed and delivered on behalf of Investor and are valid and binding agreements of Investor enforceable in accordance with their terms, subject to the effect of any applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights of creditors generally and the application of general principles of equity.

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2.9           Residency.  Investor is a resident of (or, if an entity, has its principal place of business in) the jurisdiction set forth immediately below Investor’s name on the signature page hereto.

ARTICLE III
REPRESENTATIONS AND WARRANTIES OF THE COMPANY

The Company represents and warrants to Investor that:

3.1           Organization and Qualification.  The Company is duly incorporated, validly existing and in good standing under the laws of the jurisdiction in which it is incorporated, with full power and authority (corporate and other) to own, lease, use and operate its properties and to carry on its business as and where now owned, leased, used, operated and conducted.  The Company is duly qualified to do business and is in good standing in every jurisdiction in which the nature of the business conducted by it makes such qualification necessary, except where the failure to be so qualified or in good standing would not have a Material Adverse Effect.

3.2           Authorization; Enforcement.  (a) The Company has all requisite corporate power and authority to enter into and to perform its obligations under this Agreement, the Registration Rights Agreement and the Warrant, to consummate the transactions contemplated hereby and thereby and to issue the Securities in accordance with the terms hereof and thereof; (b) the execution, delivery and performance of this Agreement, the Registration Rights Agreement and the Warrant by the Company and the consummation by it of the transactions contemplated hereby and thereby (including without limitation the issuance of the Securities) have been duly authorized by the Company’s Board of Directors and no further consent or authorization of the Company, its Board or Directors, or its shareholders is required; (c) this Agreement, the Registration Rights Agreement and the Warrant have been duly executed by the Company; and (d) each of this Agreement, the Registration Rights Agreement and the Warrant constitutes a legal, valid and binding obligation of the Company enforceable against the Company in accordance with its terms, subject to the effect of any applicable bankruptcy, insolvency, reorganization, or moratorium or similar laws affecting the rights of creditors generally and the application of general principles of equity.

3.3           Capitalization.  As of the date hereof, the authorized capital stock of the Company consists of (a) 75,000,000 shares of Common Stock, par value $.001 per share, of which 26,301,142 shares are issued and outstanding, 2,916,783 shares are reserved for issuance upon exercise of stock options outstanding under the Company’s employee and director stock option plans, 1,341,677 shares are reserved for grants of rights to purchase under the Company’s employee and director stock option plans, 39,650 shares are reserved for issuance pursuant to the Company’s employee stock purchase plan and 401(k) plan and 3,929,052 shares are reserved for issuance under warrants issued by the Company on June 15, 2001, January 18, 2002, July 28, 2003, and August 15, 2005, and (b) 5,000,000 shares of preferred stock, par value $.001 per share, 500,000 of which shares are designated Series A Junior Participating Preferred Stock, par value $.001 per share, none of which is issued and outstanding.  All of such outstanding shares of capital stock are, or upon issuance will be, duly authorized, validly issued, fully paid and nonassessable.  No shares of capital stock of the Company, including the Securities issuable pursuant to this Agreement, are subject to preemptive rights or any other similar rights of the stockholders of the Company or any liens or encumbrances imposed through the actions or failure to act of the Company.  Except as disclosed in this Section 3.3 and except for the transactions contemplated hereby, (i) there are no outstanding options, warrants, scrip,

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rights to subscribe for, puts, calls, rights of first refusal or preemptive or other similar rights, agreements, understandings, claims or other commitments or rights of any character whatsoever relating to, or securities or rights directly or indirectly convertible into, exercisable for, or exchangeable for any shares of capital stock of the Company, or arrangements by which the Company is or may become bound to issue additional shares of capital stock of the Company; (ii) there are no agreements or arrangements (other than the Registration Rights Agreement, the separate Registration Rights Agreements entered into on June 15, 2001, January 18, 2002, July 28, 2003, May 7, 2004 and August 15, 2005 and the Purchase Warrants dated June 15, 2001) under which the Company is obligated to register the sale of any of its securities under the Securities Act and (iii) there are no anti-dilution or price adjustment provisions contained in any security issued by the Company (or in any agreement providing rights to security holders) that will be triggered by the issuance of the Securities (other than the exercise price adjustments pursuant to the warrants to purchase an aggregate of 385,800 shares of Common Stock, issued by the Company on January 18, 2002 and the contingent obligation to issue additional warrants to purchase an aggregate of 2,325,936 shares pursuant to the Securities Purchase Agreement dated August 15, 2005).  The Company has furnished to Investor true and correct copies of the Company’s Certificate of Incorporation, as amended, as in effect on the date hereof, the Company’s Bylaws as in effect on the date hereof and the terms of all securities convertible into or exercisable for Common Stock of the Company and the material rights of the holders thereof in respect thereto.

3.4           Issuance of Securities.  The Securities are duly authorized and, upon issuance in accordance with the terms of this Agreement, will be validly issued, fully paid and non-assessable, free from all taxes, liens, claims, encumbrances and charges with respect to the issue thereof, will not be subject to preemptive rights or other similar rights of stockholders of the Company, and will not impose personal liability on the holders thereof.  The Company has reserved a sufficient number of shares of Common Stock for issuance upon exercise of the Warrant, and upon payment of the exercise price and exercise of the Warrant in accordance with its terms, the Warrant Shares will be validly issued, fully paid and non-assessable, free from all taxes, liens, claims, encumbrances and charges with respect to the issue thereof, will not be subject to preemptive rights or other similar rights of stockholders of the Company and will not impose personal liability on the holders thereof.

3.5           No Conflicts; No Violation.

(a)           The execution, delivery and performance of this Agreement, the Registration Rights Agreement and the Warrant by the Company and the consummation by the Company of the transactions contemplated hereby and thereby (including, without limitation, the issuance of the Securities) will not (i) conflict with or result in a violation of any provision of its Certificate of Incorporation or Bylaws or (ii) violate or conflict with, or result in a breach of any provision of, or constitute a default (or an event which with notice or lapse of time or both could become a default) under, or give to others any rights of termination, amendment (including without limitation, the triggering of any anti-dilution provision), acceleration or cancellation of, any agreement, indenture, patent, patent license, or instrument to which the Company is a party, or (iii) result in a violation of any law, rule, regulation, order, judgment or decree (including U.S. federal and state securities laws and regulations and regulations of any self-regulatory organizations to which the Company or its securities are subject) applicable to the Company or by which any property or asset of the Company is bound or affected (except for such conflicts, breaches, defaults, terminations, amendments, accelerations, cancellations and violations as would not, individually or in the aggregate, have a Material Adverse Effect).

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(b)           The Company is not in violation of its Certificate of Incorporation, Bylaws or other organizational documents and the Company is not in default (and no event has occurred which with notice or lapse of time or both could put the Company in default) under any agreement, indenture or instrument to which the Company is a party or by which any property or assets of the Company is bound or affected, except for possible defaults as would not, individually or in the aggregate, have a Material Adverse Effect.

(c)           The Company is not conducting its business in violation of any law, ordinance or regulation of any governmental entity, the failure to comply with which would, individually or in the aggregate, have a Material Adverse Effect.

(d)           Except as specifically contemplated by this Agreement and as required under the Securities Act and any applicable state securities laws or any listing agreement with any securities exchange or automated quotation system, the Company is not required to obtain any consent, authorization or order of, or make any filing or registration with, any court or governmental agency or any regulatory or self regulatory agency in order for it to execute, deliver or perform any of its obligations under this Agreement, the Registration Rights Agreement or the Warrant, in each case in accordance with the terms hereof or thereof, or to issue and sell the Securities in accordance with the terms hereof.  All consents, authorizations, orders, filings and registrations which the Company is required to obtain pursuant to the preceding sentence have been obtained or effected on or prior to the date hereof.  The Company is not in violation of the listing requirements of Nasdaq.

3.6           SEC Documents, Financial Statements.  Since June 30, 2002, the Company has timely filed all reports, schedules, forms, statements and other documents required to be filed by it with the SEC pursuant to the reporting requirements of the Exchange Act (all of the foregoing filed prior to the date hereof and all exhibits included therein and financial statements and schedules thereto and documents (other than exhibits) incorporated by reference therein, being hereinafter referred to herein as the “SEC Documents”).  The Company has delivered to Investor, or Investor has had access to, true and complete copies of the SEC Documents, except for such exhibits and incorporated documents.  As of their respective dates, the SEC Documents complied in all material respects with the requirements of the Exchange Act or the Securities Act, as the case may be, and the rules and regulations of the SEC promulgated thereunder applicable to the SEC Documents, and none of the SEC Documents, at the time they were filed with the SEC, contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading.  As of their respective dates, the financial statements of the Company included in the SEC Documents complied in all material respects with applicable accounting requirements and the published rules and regulations of the SEC with respect thereto.  Such financial statements have been prepared in accordance with U.S. generally accepted accounting principles, consistently applied, during the periods involved (except (i) as may be otherwise indicated in such financial statements or the notes thereto, or (ii) in the case of unaudited interim statements, to the extent they may not include footnotes or may be condensed or summary statements) and fairly present in all material respects the financial position of the Company as of the dates thereof and the results of its operations and cash flows for the periods then ended (subject, in the case of unaudited statements, to normal year-end audit adjustments).  Except as set forth in the financial statements included in the SEC Documents, the Company has no liabilities, contingent or otherwise, other than liabilities incurred in the ordinary course of business subsequent to June 30, 2005, and liabilities of the type not required under generally accepted accounting principles to be reflected in such financial statements.  Such

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liabilities incurred subsequent to June 30, 2005, are not, in the aggregate, material to the financial condition or operating results of the Company.

3.7           Absence of Certain Changes.  Except as disclosed in the SEC Documents, since June 30, 2005, there has been no material adverse change in the assets, liabilities, business, properties, operations, financial condition, prospects or results of operations of the Company, and the Company has not (i) varied its business plan or practices, in any material respect, from past practices, (ii) entered into any material financing, joint venture, license or similar arrangements or (iii) suffered or permitted to be incurred any liability or obligation against any of its properties or assets that would limit or restrict its ability to perform its obligations hereunder.

3.8           Absence of Litigation.  Except as disclosed in the SEC Documents, there is no action, suit, claim, proceeding, inquiry or investigation before or by any court, public board, government agency, self-regulatory organization or body, (i) to the knowledge of the Company, threatened against or affecting the Company or any of its officers or directors acting as such that could, individually or in the aggregate, have a Material Adverse Effect, or (ii) pending against or affecting the Company or any of its officers or directors acting as such.

3.9           Intellectual Property Rights.  The Company owns or possesses the licenses or rights to use all patents, patent applications, patent rights, inventions, know-how, trade secrets, trademarks, trademark applications, service marks, service names, trade names and copyrights necessary to enable it to conduct its business as now operated or as currently proposed to be operated (the “Intellectual Property”).  Except as set forth in the SEC Documents, there are no material outstanding options, licenses or agreements relating to the Intellectual Property, nor is the Company bound by or a party to any material options, licenses or agreements relating to the patents, patent applications, patent rights, inventions, know-how, trade secrets, trademarks, trademark applications, service marks, service names, trade names or copyrights of any other person or entity.  Except as disclosed in the SEC Documents, there is no claim or action or proceeding pending or, to the Company’s knowledge, threatened that challenges the right of the Company with respect to any Intellectual Property.  Except as set forth in the SEC Documents, to the knowledge of the Company, the Company’s Intellectual Property does not infringe any intellectual property rights of any other person which, if the subject of an unfavorable decision, ruling or finding would have a Material Adverse Effect.

3.10         Tax Status.  The Company has timely made or filed all federal, state and foreign income and all other tax returns, reports and declarations required by any jurisdiction to which it is subject (unless and only to the extent that the Company has set aside on its books provisions reasonably adequate for the payment of all unpaid and unreported taxes) and has timely paid all taxes and other governmental assessments and charges, shown or determined to be due on such returns, reports and declarations, except those being contested in good faith, and has set aside on its books provisions reasonably adequate for the payment of all taxes for periods subsequent to the periods to which such returns, reports or declarations apply.  To the knowledge of the Company, there are no unpaid taxes claimed to be due by the taxing authority of any jurisdiction, and the officers of the Company know of no basis for any such claim.  The Company has not executed a waiver with respect to the statute of limitations relating to the assessment or collection of any foreign, federal, state or local tax.  None of the Company’s tax returns is presently being audited by any taxing authority.

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3.11         Environmental Laws.  The Company (i) is in compliance with all applicable foreign federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) has received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct its business and (iii) is in compliance with all terms and conditions of any such permit, license or approval where, in each of the three foregoing clauses, the failure to so comply would have, individually or in the aggregate, a Material Adverse Effect.

3.12         No Brokers.  The Company has taken no action which would give rise to any claim by any person for brokerage commissions, finder’s fees or similar payments relating to this Agreement or the transactions contemplated hereby.

3.13         Insurance.  The Company is insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as management of the Company believes to be prudent and customary in the businesses in which the Company is engaged.

3.14         Employment Matters.  The Company is in compliance with all federal, state, local and foreign laws and regulations respecting employment and employment practices, terms and conditions of employment and wages and hours, except where failure to be in compliance would not have a Material Adverse Effect. The Company is not bound by or subject to (and none of its assets or properties is bound by or subject to) any written or oral, express or implied, contract, commitment or arrangement with any labor union, and no labor union has requested or, to the Company’s knowledge, has sought to represent any of the employees, representatives or agents of the Company.  There is no strike or other labor dispute involving the Company pending, or to the Company’s knowledge, threatened nor is the Company aware of any labor organization activity involving its employees.  The Company is not aware that any officer or key employee, or that any group of officers or key employees, intends to terminate their employment with the Company, nor does the Company have a present intention to terminate the employment of any of the foregoing.

3.15         Employee Benefit Plans.  Except as set forth in the SEC Documents, the Company does not have any Employee Benefit Plans, as such term is defined in the Employee Retirement Security Act of 1974.

3.16         Investment Company Status.  The Company is not and upon consummation of the sale of the Securities will not be an “investment company,” a company controlled by an “investment company” or an “affiliated person” of, or “promoter” or “principal underwriter” for, an “investment company” as such terms are defined in the Investment Company Act of 1940, as amended.

3.17         No Subsidiaries.  Except for Sonus Pharma, Limited, a wholly owned subsidiary of the Company organized under the laws of the United Kingdom, the Company does not presently own or control, directly or indirectly, any interest in any other corporation, association, joint venture, partnership or other business entity and the Company is not a direct or indirect participant in any joint venture or partnership.

3.18         No Conflict of Interest.  The Company is not indebted, directly or indirectly, to any of its officers or directors or to their respective spouses or children, in any amount whatsoever other than in connection with expenses or advances of expenses incurred in the ordinary course of business or relocation expenses of employees.  None of the Company’s officers, directors or employees, or any members of their immediate families, are directly, or indirectly, indebted to the Company or, to

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the best of the Company’s knowledge, have any direct or indirect ownership interest in any entity with which the Company is affiliated or with which the Company has a business relationship, or any entity which competes with the Company, except that officers, directors, employees and/or stockholders of the Company may own stock in (but not exceeding five percent (5%) of the outstanding capital stock of) any publicly traded company that may compete with the Company.  To the best of the Company’s knowledge, none of the Company’s officers, directors or employees or any members of their immediate families are, directly or indirectly, interested in any material contract with the Company.  The Company is not a guarantor or indemnitor of any indebtedness of any other person or entity.

3.19         Nasdaq Notification.  The Company has notified Nasdaq of the issuance and listing of the Common Shares and Warrant Shares on Nasdaq and the Common Shares and Warrant Shares have been approved for quotation on Nasdaq, upon official notice of issuance.

3.20         Reporting Status; Eligibility to Use Form S-3.  The Company’s Common Stock is registered under Section 12g of the Exchange Act.  The Company currently meets the “registrant eligibility” requirements set forth in the general instructions to Form S-3 to enable the registration of the Registrable Securities, as defined in the Registration Rights Agreement.

3.21         No Manipulation of Stock.  The Company has not taken and will not, in violation of applicable law, take, any action designed to or that might reasonably be expected to cause or result in stabilization or manipulation of the price of the Common Stock to facilitate the sale or resale of the Securities.

3.22         Collaboration and License Agreement.  The representations and warranties made by the Company in Article X of that certain Collaboration and License Agreement dated as of the date hereof (the “License Agreement”), are incorporated herein by this reference and made to Investor as though fully set forth herein.

3.23         Representations Complete.  The representations and warranties made by the Company in this Agreement, the statements made in any certificates furnished by the Company pursuant to this Agreement, and the statements made by the Company in any documents mailed, delivered or furnished to Investor in connection with this Agreement, taken as a whole, do not contain and will not contain, as of their respective dates and as of the Closing Date, any untrue statement of a material fact, nor do they omit or will they omit, as of their respective dates or as of the Closing Date, to state any material fact necessary in order to make the statements contained herein or therein, in the light of the circumstances under which they were made, not misleading.

ARTICLE IV
COVENANTS

4.1           Best Efforts.  Each party will use its best efforts to satisfy in a timely fashion each of the conditions to be satisfied by it under Articles VI and VII of this Agreement.  The Company shall use its best efforts to comply with each of its covenants in this Agreement, the Registration Rights Agreement and the Warrant, unless the use of best efforts conflicts with the standard of conduct set forth in any such covenant, in which case such other standard of conduct shall control.

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4.2           Form D; Blue Sky Laws.  The Company will timely file a Notice of Sale of Securities on Form D with respect to the Securities, as required under Regulation D.  The Company will, on or before the Closing Date, take such action as it reasonably determines to be necessary to qualify the Securities for sale to Investor under this Agreement under applicable securities (or “blue sky”) laws of the states of the United States (or to obtain an exemption from such qualification).

4.3           Continued Eligibility to Use Form S-3.  Throughout the Registration Period (as defined in the Registration Rights Agreement), the Company will timely file all reports, schedules, forms, statements and other documents required to be filed by it with the SEC under the reporting requirements of the Exchange Act, and the Company will not terminate its status as an issuer required to file reports under the Exchange Act even if the Exchange Act or the rules and regulations thereunder would permit such termination.  The Company will take all reasonably necessary action to continue to meet the “registrant eligibility” requirements set forth in the general instructions to Form S-3 to enable the registration of the Registrable Securities as defined in the Registration Rights Agreement.

4.4           Expenses.  The Company and Investor are liable for, and will pay, its own expenses incurred in connection with the negotiation, preparation, execution and delivery of this Agreement and the other agreements to be executed in connection herewith, including, without limitation, attorneys’ and consultants’ fees and expenses.

4.5           Financial Information.  As long as Investor owns any of the Securities or Warrant Shares, the financial statements of the Company will be prepared in accordance with United States generally accepted accounting principles, consistently applied, and will fairly present in all material respects the consolidated financial position of the Company and results of its operations and cash flows as of, and for the periods covered by, such financial statements (subject, in the case of unaudited statements, to normal year-end audit adjustments).

4.6           Compliance with Law.  As long as Investor owns any of the Securities or Warrant Shares, the Company will conduct its business in compliance with all applicable laws, rules and regulations of the jurisdictions in which it is conducting business, including, without limitation, all applicable local, state and federal environmental laws and regulations, the failure to comply, individually or in the aggregate, with which would have a Material Adverse Effect.

4.7           Sales by Investor.  Investor will sell any Securities sold by it in compliance with applicable prospectus delivery requirements, if any, or otherwise in compliance with the requirements for an exemption from registration under the Securities Act and the rules and regulations promulgated thereunder and the restrictions on sales or transfers set forth in the Registration Rights Agreement.  Investor will not make any sale, transfer or other disposition of the Securities in violation of federal or state securities laws.

ARTICLE V
TRANSFER AGENT INSTRUCTIONS; REMOVAL OF LEGENDS

5.1           Issuance of Certificates.  The Company will, or will instruct its transfer agent to, issue certificates, registered in the name of Investor or its nominee, for the Securities and, promptly upon exercise of any portion of the Warrant Shares.  All such certificates will bear the restrictive legend described in Section 2.7, except as otherwise specified in this Article V.  The Company will

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not give to its transfer agent any instruction other than as described in this Article V and stop transfer instructions to give effect to Section 2.7 hereof (prior to registration of the Securities under the Securities Act).  Nothing in this Section will affect in any way Investor’s obligations to comply with all applicable prospectus delivery requirements, if any, upon resale of the Common Shares and/or Warrant Shares.

5.2           Unrestricted Securities.  If, unless otherwise required by applicable state securities laws, (a) the Securities or Warrant Shares represented by a certificate have been registered under an effective registration statement filed under the Securities Act, (b) a holder of Securities or Warrant Shares provides the Company and its transfer agent with an opinion of counsel, in form, substance and scope customary for opinions of counsel in comparable transactions, to the effect that a public sale or transfer of such Securities or Warrant Shares may be made without registration under the Securities Act and such sale either has occurred or may occur without restriction on the manner of such sale or transfer, (c) such holder provides the Company and its transfer agent with reasonable assurances that such Securities or Warrant Shares can be sold under Rule 144, or (d) the Common Shares represented by a certificate can be sold without restriction as to the number of securities sold under Rule 144(k), the Company will permit the transfer of the Securities or Warrant Shares, and the Company’s transfer agent will issue one or more certificates, free from any restrictive legend, in such name and in such denominations as specified by such holder.  Notwithstanding anything herein to the contrary, the Securities or Warrant Shares may be pledged as collateral in connection with a bona fide margin account or other lending arrangement; provided, that such pledge will not alter the provisions of this Article V with respect to the removal of restrictive legends.

5.3           Enforcement of Provision.  The Company acknowledges that a breach by it of its obligations hereunder will cause irreparable harm to Investor by vitiating the intent and purpose of the transaction contemplated hereby.  Accordingly, the Company acknowledges that the remedy at law for a breach of its obligations under this Article V will be inadequate and agrees, in the event of a breach or threatened breach by the Company of the provisions of this Section, that Investor will be entitled, in addition to all other available remedies, to an injunction restraining any breach and requiring immediate transfer of the Securities and/or Warrant Shares, as applicable, without the necessity of showing economic loss and without any bond or other security being required.

ARTICLE VI
CONDITIONS TO THE COMPANY’S OBLIGATION TO SELL

The obligation of the Company to issue and sell the Securities to Investor at the Closing is subject to the satisfaction by such Investor, on or before the Closing Date, of each of the following conditions.  These conditions are for the Company’s sole benefit and may be waived by the Company at any time in its sole discretion:

6.1           Investor will have executed this Agreement, the Registration Rights Agreement, the Warrant and the License Agreement and will have delivered those agreements to the Company.

6.2           Investor will have delivered the purchase price for the Securities to the Company in accordance with this Agreement.

6.3           The representations and warranties of Investor must be true and correct in all material respects as of the Closing Date as though made at that time (except for representations and warranties

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that speak as of a specific date, which representations and warranties must be correct as of such date), and Investor will have performed and complied in all material respects with the covenants and conditions required by this Agreement to be performed or complied with by Investor at or prior to the Closing.

6.4           No statute, rule, regulation, executive order, decree, ruling or injunction will have been enacted, entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory organization having authority over the matters contemplated hereby which prohibits the consummation of any of the transactions contemplated by this Agreement, the Registration Rights Agreement or the Warrant.

ARTICLE VII
CONDITIONS TO THE INVESTOR’S OBLIGATION TO PURCHASE

The obligation of Investor hereunder to purchase the Securities from the Company at the Closing is subject to the satisfaction, on or before the Closing Date, of each of the following conditions.  These conditions are for Investor’s benefit and may be waived by Investor at any time in its sole discretion:

7.1           The Company will have executed this Agreement, the Registration Rights Agreement, the Warrant and the License Agreement and will have delivered those Agreements to Investor.

7.2           Investor shall have received an opinion of counsel from Stradling Yocca Carlson & Rauth, counsel to the Company, reasonably acceptable to Investor and its counsel.

7.3           Each of the representations and warranties of the Company qualified by materiality must be true and correct in all respects as of the Closing as though made at that time (except for representations and warranties that speak as of a specific date, which representations and warranties must be true and correct as of such date) and each of the representations and warranties of the Company not qualified by materiality must be true and correct in all material respects as of the Closing as though made at that time (except for representations and warranties that speak as of a specific date, which representations and warranties must be true and correct as of such date) and the Company must have performed and complied in all material respects with the covenants and conditions required by this Agreement to be performed or complied with by the Company at or prior to the Closing.  Investor must have received a certificate or certificates dated as of the Closing Date and executed by the Chief Executive Officer or the Chief Financial Officer of the Company certifying as to the matters in contained in this Section 7.3 and as to such other matters as may be reasonably requested by such Investor, including, but not limited to, the Company’s Certificate of Incorporation, Bylaws, Board of Directors’ resolutions relating to the transactions contemplated hereby and the incumbency and signatures of each of the officers of the Company who may execute on behalf of the Company any document delivered at the Closing.

7.4           No litigation, statute, rule, regulation, executive order, decree, ruling or injunction will have been enacted, entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory organization having authority over the matters contemplated hereby which prohibits the consummation of any of the transactions

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contemplated by this Agreement, the Registration Rights Agreement or the Warrant and which could, individually or in the aggregate, have a Material Adverse Effect.

7.5           Trading and listing of the Common Stock on Nasdaq must not have been suspended by the SEC or Nasdaq.

7.6           Investor shall have received certificates representing the Common Shares and the Warrant.

ARTICLE VIII
INDEMNIFICATION

In consideration of Investor’s execution and delivery of this Agreement and its acquisition of the Securities hereunder, and in addition to all of the Company’s other obligations under this Agreement, the Registration Rights Agreement and the Warrant, the Company will defend, protect, indemnify and hold harmless Investor and each other holder of the Securities and all of their stockholders, officers, directors, employees and direct or indirect investors and any of the foregoing person’s agents or other representatives (including, without limitation, those retained in connection with the transactions contemplated by this Agreement) (collectively, the “Indemnitees”) from and against any and all actions, causes of action, suits, claims, losses, costs, penalties, fees, liabilities and damages, and expenses in connection therewith (regardless of whether any such Indemnitee is a party to the action for which indemnification hereunder is sought), and including reasonable attorneys’ fees and disbursements (the “Indemnified Liabilities”), incurred by an Indemnitee as a result of, or arising out of, or relating to (a) any breach of any representation or warranty made by the Company herein or in any other certificate, instrument or document contemplated hereby or thereby, (b) any breach of any covenant, agreement or obligation of the Company contained herein or in any other certificate, instrument or document contemplated hereby or thereby or (c) any cause of action, suit or claim brought or made against such Indemnitee and arising out of or resulting from the execution, delivery, performance, breach or enforcement of this Agreement, the Registration Rights Agreement or the Warrant by the Company.  To the extent that the foregoing undertaking by the Company is unenforceable for any reason, the Company will make the maximum contribution to the payment and satisfaction of each of the Indemnified Liabilities that is permissible under applicable law.

The Indemnitees shall have the right to employ separate counsel in any such proceeding and to participate in the defense thereof, but the fees and expenses of such counsel shall be at the expense of such Indemnitees unless: (i) the Company has agreed in writing to pay such fees and expenses; (ii) the Company shall have failed to promptly assume the defense of such proceeding and to employ counsel reasonably satisfactory to such Indemnitees in any such proceeding; or (iii) the named parties to any such proceeding (including any impleaded parties) include both such Indemnitees and the Company, and such Indemnitees shall have been advised by counsel that a conflict of interest is likely to exist if the same counsel were to represent such Indemnitees and the Company (in which case, if such Indemnitees notify the Company in writing that they elect to employ separate counsel at the expense of the Company, the Company shall not have the right to assume the defense thereof and such counsel shall be at the reasonable expense of the Company; provided, however, that in no event shall the Company be responsible for the fees and expenses of more than one separate counsel).  The Company shall not be liable for any settlement of any such proceeding effected without its written consent, which consent shall not be unreasonably withheld.  The Company shall not, without the prior written consent of a majority of the Indemnitees, effect any settlement of any pending

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proceeding in respect of which Indemnitees are a party, unless such settlement includes an unconditional release of such Indemnitees from all liabilities that are the subject matter of such proceeding.  Subject to the foregoing, all fees and expenses (including reasonable fees and expenses to the extent incurred in connection with investigating or preparing to defend any such proceeding in a manner inconsistent with this Article VIII) of the Indemnitees shall be paid to the Indemnitees as incurred, within ten (10) business days of written notice thereof to the Company, which notice shall be delivered no more frequently than on a monthly basis; provided, that the Indemnitees shall reimburse the Company for any and all such fees and expenses to the extent it is finally judicially determined that such Indemnitees are not entitled to indemnification hereunder.

ARTICLE IX
DEFINITIONS

9.1           “Closing” means the closing of the purchase and sale of the Securities under this Agreement.

9.2           “Closing Date” has the meaning set forth in Section 1.3.

9.3           “Common Shares” has the meaning set forth in the Recitals.

9.4           “Common Stock” means the common stock, par value $.001 per share, of the Company.

9.5           “Company” means Sonus Pharmaceuticals, Inc.

9.6           “Exchange Act” means the Securities Exchange Act of 1934, as amended.

9.7           “Indemnified Liabilities” has the meaning set forth in Article VIII.

9.8           “Indemnitees” has the meaning set forth in Article VIII.

9.9           “Investor” has the meaning set forth in the preamble of this Agreement.

9.10         “License Agreement” has the meaning set forth in Section 3.22.

9.11         “Material Adverse Effect” means a material adverse effect on (a) the business, operations, prospects, assets or financial condition of the Company or (b) the ability of the Company to perform its obligations pursuant to the transactions contemplated by this Agreement or under the agreements or instruments to be entered into or filed in connection herewith, including the Registration Rights Agreement and the Warrant.

9.12         “Nasdaq” means the Nasdaq National Market System.

9.13         “Registration Rights Agreement” means the Registration Rights Agreement, dated as of the date of this Agreement and among the parties to this Agreement, in the form attached hereto as Exhibit C.

9.14         “Regulation D” means Regulation D as promulgated under by the SEC under the Securities Act.

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9.15         “Rule 144” and “Rule 144(k)” mean Rule 144 and Rule 144(k), respectively, promulgated under the Securities Act, or any successor rule.

9.16         “SEC” means the United States Securities and Exchange Commission.

9.17         “SEC Documents” has the meaning set forth in Section 3.6.

9.18         “Securities” has the meaning set forth in the Recitals.

9.19         “Securities Act” means the Securities Act of 1933, as amended, and the rules and regulations thereunder, or any similar successor statute.

9.20         “Warrant” and “Warrant Shares” have the meanings set forth in the Recitals.

ARTICLE X
GOVERNING LAW; MISCELLANEOUS

10.1         Governing Law; Jurisdiction; Jury Trial Waiver.  This Agreement will be governed by and interpreted in accordance with the laws of the State of New York without regard to the principles of conflict of laws.  The parties hereto hereby submit to the exclusive jurisdiction of the United States federal and state courts located in the State of New York with respect to any dispute arising under this Agreement, the agreements entered into in connection herewith or the transactions contemplated hereby or thereby. EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT THAT IT MAY HAVE TO, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR WITH ANY TRANSACTION CONTEMPLATED HEREBY.

10.2         Counterparts; Signatures by Facsimile.  This Agreement may be executed in two or more counterparts, all of which are considered one and the same agreement and will become effective when counterparts have been signed by each party and delivered to the other parties.  This Agreement, once executed by a party, may be delivered to the other parties hereto by facsimile transmission of a copy of this Agreement bearing the signature of the party so delivering this Agreement.

10.3         Headings.  The headings of this Agreement are for convenience of reference only, are not part of this Agreement and do not affect its interpretation.

10.4         Severability.  If any provision of this Agreement is invalid or unenforceable under any applicable statute or rule of law, then such provision will be deemed modified in order to conform with such statute or rule of law.  Any provision hereof that may prove invalid or unenforceable under any law will not affect the validity or enforceability of any other provision hereof.

10.5         Entire Agreement; Amendments.  This Agreement, the Registration Rights Agreement and the Warrant (including all schedules and exhibits thereto) and the Warrant constitute the entire agreement among the parties hereto with respect to the subject matter hereof and thereof.  There are no restrictions, promises, warranties or undertakings, other than those set forth or referred to herein or therein.  This Agreement supersedes all prior agreements and understandings among the parties hereto with respect to the subject matter hereof.  No provision of this Agreement may be

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waived or amended other than by an instrument in writing signed by the party to be charged with enforcement.

10.6         Notices.  Any notices required or permitted to be given under the terms of this Agreement must be sent by certified or registered mail (return receipt requested) or delivered personally or by courier (including a recognized overnight delivery service) or by facsimile and will be effective three business days after being placed in the mail, if mailed by regular U.S. mail, or upon receipt, if delivered personally, by courier (including a recognized overnight delivery service) or by facsimile, in each case addressed to a party.  The addresses for such communications are:

If to Investor:  To the address set forth immediately below Investor’s name on the signature pages hereto.

Each party will provide written notice to the other parties of any change in its address in accordance with the notice provisions hereof.

10.7         Successors and Assigns.  This Agreement is binding upon and inures to the benefit of the parties and their successors and assigns.  The Company will not assign this Agreement or any rights or obligations hereunder without the prior written consent of Investor, and Investor may not assign this Agreement or any rights or obligations hereunder without the prior written consent of the Company.  Notwithstanding the foregoing, Investor may assign all or part of its rights and obligations hereunder to any of its “affiliates,” as that term is defined under the Securities Act, without the consent of the Company so long as the affiliate is an accredited investor (within the meaning of Regulation D under the Securities Act) and agrees in writing to be bound by this Agreement.  This provision does not limit Investor’s right to transfer the Securities pursuant to the terms of this Agreement or to assign Investor’s rights hereunder to any such transferee pursuant to the terms of this Agreement.

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10.8         Third Party Beneficiaries.  This Agreement is intended for the benefit of the parties hereto and their respective permitted successors and assigns, and, except as contemplated in Section 2.10, is not for the benefit of, nor may any provision hereof be enforced by, any other person.

10.9         Survival.  The representations and warranties of the Company and the agreements and covenants set forth herein will survive the Closing hereunder for a period of twelve (12) months.  The Company makes no representations or warranties in any oral or written information provided to Investor, other than the representations and warranties included herein.

10.10       Further Assurances.  Each party will do and perform, or cause to be done and performed, all such further acts and things, and will execute and deliver all other agreements, certificates, instruments and documents, as another party may reasonably request in order to carry out the intent and accomplish the purposes of this Agreement and the consummation of the transactions contemplated hereby.

10.11       No Strict Construction.  The language used in this Agreement is deemed to be the language chosen by the parties to express their mutual intent, and no rules of strict construction will be applied against any party.

10.12       Equitable Relief.  The Company recognizes that, if it fails to perform or discharge any of its obligations under this Agreement, any remedy at law may prove to be inadequate relief to Investor.  The Company therefore agrees that Investor is entitled to seek temporary and permanent injunctive relief in any such case.

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IN WITNESS WHEREOF, the undersigned Investor and the Company have caused this Securities Purchase Agreement to be duly executed as of the date first above written.

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Exhibit A

Warrant

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY STATE SECURITIES LAWS AND MAY NOT BE SOLD, EXCHANGED, HYPOTHECATED OR TRANSFERRED IN ANY MANNER EXCEPT PURSUANT TO A REGISTRATION OR AN EXEMPTION FROM SUCH REGISTRATION.

PURCHASE WARRANT

Issued to:

Schering AG

Exercisable to Purchase

975,000 Shares of Common Stock

of

SONUS PHARMACEUTICALS, INC.

Void after October 17, 2010

This is to certify that, for the value described herein and subject to the terms and conditions set forth below, the Warrantholder is entitled to purchase, and the Company promises and agrees to sell and issue to the Warrantholder, at any time on or after October 17, 2005 (the “Effective Date”), pursuant to Section 3 hereof, up to 975,000 shares of the Company’s Common Stock at the Exercise Price.

This Warrant certificate is issued subject to the following terms and conditions:

1.             Definitions of Certain Terms.  Except as may be otherwise clearly required by the context, the following terms have the following meanings:

(a)           “Common Stock” means the common stock, $0.001 par value, of the Company.

(b)           “Company” means Sonus Pharmaceuticals, Inc., a Delaware corporation.

(c)           “Effective Date” has the meaning set forth in the preamble to this Agreement.

(d)           “Exercise Period” means the period of time commencing on the Effective Date and ending at 5 p.m. Pacific Standard Time on the fifth anniversary of the Effective Date.

(e)           “Exercise Price” means the price at which the Warrantholder may purchase one Share upon exercise of Warrants as determined from time to time pursuant to the provisions hereof.  The initial Exercise Price is $4.42 per Share, which is equal to 110% of the purchase price per share of Common Stock paid by Warrantholder under the Securities Purchase Agreement.

(f)            “Registration Rights Agreement” means the Registration Rights Agreement dated as of October 17, 2005 between the Company and the Investor referenced therein.

(g)           “Securities Act” means the Securities Act of 1933, as amended.

(h)           “Securities Purchase Agreement” means the Securities Purchase Agreement dated as of October 17, 2005 between the Company and the Investor referenced therein.

(i)            “Share” or “Shares” refers to one or more shares of Common Stock issuable on exercise of the Warrant.

(j)            “Warrant” means the warrant evidenced by this certificate or any certificate obtained upon transfer or partial exercise of the Warrant evidenced by any such certificate.

(k)           “Warrantholder” means a record holder of the Warrant or Shares.  The initial Warrantholder is Schering AG.

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2.             Purchase of Warrant.  Concurrently with the issuance hereof, the Warrantholder shall pay to the Company as consideration for the Warrant the sum of $0.125 per Share issuable upon exercise of the Warrant, or $121,875 in the aggregate.

3.             Exercise of Warrants.

(a)           All or any part of the Warrant may be exercised during the Exercise Period by surrendering the Warrant, together with appropriate instructions, duly executed by the Warrantholder or by its duly authorized attorney, and delivery of payment in full by the Warrantholder, in lawful money of the United States, of the Exercise Price payable with respect to the Shares being purchased at the office of the Company, 22026 20^th Avenue S.E., Bothell, Washington, 98021, Attention: President, or at such other office or agency as the Company may designate.  The date on which such instructions and the Exercise Price are received by the Company shall be the date of exercise.  Upon receipt of notice of exercise and the Exercise Price, the Company shall immediately instruct its transfer agent to prepare certificates for the Shares to be received by the Warrantholder and shall use commercially reasonable efforts to cause such certificates to be prepared and delivered to the Warrantholder in accordance with the Warrantholder’s instructions within three business days after the date of exercise.  If the Warrantholder shall provide the Company with an opinion of counsel to the effect that the legend set forth on the face of this Warrant is not required, such certificates shall not bear a legend with respect to the Securities Act.

(b)           If fewer than all the Shares purchasable under the Warrant are purchased, the Company will, upon such partial exercise, execute and deliver to the Warrantholder a new Warrant certificate (dated the date hereof), in form and tenor similar to this Warrant certificate, evidencing that portion of the Warrant not exercised.  The Shares to be obtained on exercise of the Warrant will be deemed to have been issued, and any person exercising the Warrant will be deemed to have become a holder of record of those Shares, as of the date of the payment of the Exercise Price.

4.             Adjustments in Certain Events.  The number, class, and price of the Shares for which this Warrant is exercisable are subject to adjustment from time to time upon the happening of certain events as follows:

(a)           If the outstanding shares of the Company’s Common Stock are divided into a greater number of shares or a dividend in stock is paid on the Common Stock, the number of Shares for which the Warrant is then exercisable will be proportionately increased and the Exercise Price will be proportionately reduced; and, conversely, if the outstanding shares of Common Stock are combined into a smaller number of shares of Common Stock, the number of Shares for which the Warrant is then exercisable will be proportionately reduced and the Exercise Price will be proportionately increased.  The increases and reductions provided for in this subsection 4(a) will be made with the intent and, as nearly as practicable, the effect that neither the percentage of the total equity of the Company obtainable on exercise of the Warrants nor the price payable for such percentage upon such exercise will be affected by any event described in this subsection 4(a).

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(b)           In case of any change in the Common Stock through merger, consolidation, reclassification, reorganization, partial or complete liquidation, purchase of substantially all the assets of the Company, or other change in the capital structure of the Company, then, as a condition of such change, lawful and adequate provision will be made so that the holder of this Warrant will have the right thereafter to receive upon the exercise of the Warrant the kind and amount of shares of stock or other securities or property to which he would have been entitled if, immediately prior to such event, he had held the number of Shares obtainable upon the exercise of the Warrant.  In any such case, appropriate adjustment will be made in the application of the provisions set forth herein with respect to the rights and interest thereafter of the Warrantholder, to the end that the provisions set forth herein will thereafter be applicable, as nearly as reasonably may be, in relation to any shares of stock or other property thereafter deliverable upon the exercise of the Warrant.  The Company will not permit any change in its capital structure to occur unless the issuer of the shares of stock or other securities to be received by the holder of this Warrant, if not the Company, agrees to be bound by and comply with the provisions of this Warrant.

(c)           When any adjustment is required to be made in the number of Shares or other securities or property purchasable upon exercise of the Warrant, the Company will promptly determine the new number of such Shares or other securities or property purchasable upon exercise of the Warrant and (i) prepare and retain on file a statement describing in reasonable detail the method used in arriving at the new number of such Shares or other securities or property purchasable upon exercise of the Warrant and (ii) cause a copy of such statement to be mailed to the Warrantholder within thirty (30) days after the date of the event giving rise to the adjustment.

(d)           No fractional shares of Common Stock or other securities will be issued in connection with the exercise of the Warrant, but the Company will pay, in lieu of fractional shares, a cash payment therefor on the basis of the mean between the bid and asked prices of the Common Stock in the over-the-counter market or the closing price on a national securities exchange on the day immediately prior to exercise.

(e)           If securities of the Company or securities of any subsidiary of the Company are distributed pro rata to holders of Common Stock, such number of such securities will be distributed to the Warrantholder or his assignee upon exercise of this Warrant as the Warrantholder or assignee would have been entitled to if the portion of the Warrant evidenced by this Warrant certificate had been exercised prior to the record date for such distribution.  The provisions with respect to adjustment of the Common Stock provided in this Section 4 will also apply to the securities to which the Warrantholder or his assignee is entitled under this subsection 4(e).

(f)            In the event (i) the Company establishes a record date to determine the holders of any class of securities who are entitled to receive any dividend or other distribution or (ii) there occurs any change in the Common Stock through merger, consolidation, reclassification, reorganization, partial or complete liquidation, purchase of substantially all of the assets of the Company or other change in the capital structure of the Company, the Company shall give to the holder hereof a notice specifying (a) the date of such record date for the purpose of such dividend or distribution and a description of such dividend or distribution, (b) the date on which any such merger, consolidation,

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reclassification, reorganization, sale, liquidation or other change in the capital structure of the Company is expected to become effective, and (c) the time, if any, that is to be fixed, as to when the holders of record of Common Stock (or other securities) shall be entitled to exchange their shares of Common Stock (or other securities) for securities or other property deliverable upon such merger, consolidation, reclassification, reorganization, sale, liquidation or other change in the capital structure of the Company.  Such written notice shall be given to the holder of this Warrant at least twenty (20) days prior to the date specified in such notice on which any such action is to be taken.

5.             Reservation of Shares.  The Company agrees that the number of shares of Common Stock or other securities sufficient to provide for the exercise of the Warrant upon the basis set forth above will at all times during the term of the Warrant be reserved for exercise.  If at any time the Company does not have a sufficient number of shares of Common Stock or other securities authorized to provide for the exercise of the Warrant, the Company shall take such actions as may be reasonably necessary to increase the number of authorized shares of Common Stock or other securities to provide for exercise of the Warrant.

6.             Validity of Shares.  All Shares or other securities delivered upon the exercise of the Warrant will be duly and validly issued in accordance with their terms, and, in the case of capital stock, will, when issued and delivered in accordance with their terms against payment therefor as provided in the Warrant, be fully paid and nonassessable, and the Company will pay all documentary and transfer taxes, if any, in respect of the original issuance thereof upon exercise of the Warrant.

7.             Restrictions on Transfer. This Warrant and the Shares may not be sold, transferred, assigned or hypothecated except as permitted pursuant to Section 2.6 of the Securities Purchase Agreement and subject to the restrictions on transfer in the Registration Rights Agreement.  The Warrant may be divided or combined, upon request to the Company by the Warrantholder, into a certificate or certificates evidencing the same aggregate number of Warrants.

8.             No Rights as a Stockholder.  Except as otherwise provided herein, the Warrantholder will not, by virtue of ownership of the Warrant, be entitled to any rights of a stockholder of the Company but will, upon written request to the Company, be entitled to receive such quarterly or annual reports as the Company distributes to its stockholders.

9.             Notice.  Any notices required or permitted to be given under the terms of this Warrant must be sent by certified or registered mail (return receipt requested) or delivered personally or by courier (including a recognized overnight delivery service) or by facsimile and will be effective five (5) days after being placed in the mail, if mailed by regular U.S. mail, or upon receipt, if delivered personally, by courier (including a recognized overnight delivery service) or by facsimile, in each case addressed to a party.  The addresses for such communications are:

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If to the Company:

Chief Financial Officer

Sonus Pharmaceuticals, Inc.

22026 20th Avenue S.E.

Bothell, Washington 98021

fax:          (425) 489-0626

If to a Warrantholder:  to the address set forth immediately below the Warrantholder’s name on the signature pages hereto.

With copies to:

Schering AG

Legal Department

170-178 Muellerstrasse

D-13342 Berlin, Germany

Fax:         +49-(0)30-468-14086

Each party will provide written notice to the other parties of any change in its address.

10.           Applicable Law.  This Warrant will be governed by and construed in accordance with the laws of the State of New York, without reference to conflict of laws principles thereunder.

11.           Entire Agreement.  This Warrant, the exhibits and schedules hereto, and the documents referred to herein, constitute the entire agreement and understanding of the parties hereto with respect to the subject matter hereof, and supersede all prior and contemporaneous agreements and understandings, whether oral or written, between the parties hereto with respect to the subject matter hereof.

12.           Waiver; Consent.  This Warrant may not be changed, amended, terminated, augmented, rescinded or discharged (other than by performance), in whole or in part, except by a writing executed by the parties hereto, and no waiver of any of the provisions or conditions of this Warrant or any of the rights of a party hereto shall be effective or binding unless such waiver shall be in writing and signed by the party claimed to have given or consented thereto.

13.           No Impairment.  The Company will not, by amendment of its Charter or by any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the Warrantholder of this Warrant against impairment.

14.           Remedies.  The Company stipulates that the remedies at law of the Warrantholder of this Warrant in the event of any default or threatened default by the Company in the performance of or compliance with any of the terms of this Warrant are not adequate and may be enforced by a decree for the specific performance of any agreement

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contained herein or by an injunction against a violation of any of the terms hereof or otherwise.

15.           Severability.  If one or more provisions of this Warrant are held to be unenforceable under applicable law, such provision shall be excluded from this Warrant and the balance of the Warrant shall be interpreted as if such provision were so excluded and the balance shall be enforceable in accordance with its terms.

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IN WITNESS WHEREOF, the parties hereto have executed this Warrant effective as of the date set forth below.

NOTICE OF EXERCISE

To:          SONUS PHARMACEUTICALS, INC.

The undersigned hereby elects to purchase            shares of Common Stock (the “Shares”) of Sonus Pharmaceuticals, Inc., a Delaware corporation (the “Company”) pursuant to the terms of the attached Warrant, and tenders herewith payment of the purchase price pursuant to the terms of the Warrant.

Please issue certificates representing the Common Stock purchased hereunder in the names and in the denominations indicated below.

Please issue a new Warrant for the unexercised portion of the attached Warrant, if any, in the name of the undersigned.

Exhibit B

Wire Transfer Instructions

Exhibit C

Registration Rights Agreement