NxStage Medical, Inc. 3,200,000 Shares Common Stock ($0.001 par value) Underwriting Agreement

Exhibit 1.01

NxStage Medical, Inc.

3,200,000 Shares

Common Stock

($0.001 par value)

Underwriting Agreement

November 17, 2010

Canaccord Genuity Inc.
00 Xxxx Xxxxxx, 00xx Xxxxx
Xxxxxx, XX 00000

Ladies and Gentlemen:

NxStage Medical, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to Canaccord Genuity Inc. (the “Underwriters”) pursuant to this Underwriting Agreement (this “Agreement”) an aggregate of 3,200,000 shares (the “Firm Shares”) of common stock, $0.001 par value (the “Common Stock”), of the Company. In addition, solely for the purpose of covering over-allotments, the Company proposes to grant to the Underwriters the option to purchase from the Company up to an additional 480,000 shares of Common Stock (the “Additional Shares”). The Firm Shares and the Additional Shares are hereinafter collectively referred to as the “Shares.” The Shares are described in the Prospectus which is referred to below.

The Company has prepared and filed, in accordance with the provisions of the Securities Act of 1933, as amended, and the rules and regulations thereunder (collectively, the “Act”), with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (File No. 333-170654) under the Act (the “registration statement”), including a prospectus, which registration statement incorporates by reference documents which the Company has filed, or will file, in accordance with the provisions of the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (collectively, the “Exchange Act”). Such registration statement has become effective under the Act.

Except where the context otherwise requires, “Registration Statement,” as used herein, means the registration statement, as amended at the time of such registration statement’s effectiveness for purposes of Section 11 of the Act, as such section applies to the Underwriters (the “Effective Time”), including (i) all documents filed as a part thereof or incorporated or deemed to be incorporated by reference therein and (ii) any information contained or incorporated by reference in a prospectus filed with the Commission pursuant to Rule 424(b) under the Act, to the extent such information is deemed, pursuant to Rule 430B or Rule 430C under the Act, to be part of the registration statement at the Effective Time.

Except where the context otherwise requires, “Basic Prospectus,” as used herein, means the base prospectus included as part of the Registration Statement, in the form in which it has most recently been filed with the Commission prior to the date of this Agreement. Except where the context otherwise requires, “Prospectus Supplement,” as used herein, means the final prospectus supplement, relating to the Shares, filed by the Company with the Commission

pursuant to Rule 424(b) under the Act on or before the second business day after the date hereof (or such earlier time as may be required under the Act), in the form furnished by the Company to the Underwriters for use by the Underwriters and by dealers in connection with the offering of the Shares. Except where the context otherwise requires, “Prospectus,” as used herein, means the Basic Prospectus as supplemented by the Prospectus Supplement.

“Permitted Free Writing Prospectuses,” as used herein, means the documents listed on Schedule B attached hereto. The Underwriters have not offered or sold and will not offer or sell, without the Company’s consent, any Shares by means of any “free writing prospectus” (as defined in Rule 405 under the Act) that is required to be filed by the Underwriters with the Commission pursuant to Rule 433 under the Act, other than a Permitted Free Writing Prospectus.

“Disclosure Package,” as used herein, means the Basic Prospectus, together with the Permitted Free Writing Prospectuses, if any, and the information set forth on Schedule C attached hereto, taken as a whole.

Any reference herein to the Registration Statement, the Basic Prospectus, the Prospectus Supplement, the Prospectus or any Permitted Free Writing Prospectus shall be deemed to refer to and include the documents, if any, incorporated by reference, or deemed to be incorporated by reference, therein (each an “Incorporated Document” and collectively, the “Incorporated Documents”), including, unless the context otherwise requires, the documents, if any, filed as exhibits to such Incorporated Documents. Any reference herein to the terms “amend,” “amendment” or “supplement” with respect to the Registration Statement, the Basic Prospectus, the Prospectus Supplement, the Prospectus or any Permitted Free Writing Prospectus shall be deemed to refer to and include the filing of any document under the Exchange Act on or after the initial effective date of the Registration Statement, or the date of the Basic Prospectus, the Prospectus Supplement, the Prospectus or such Permitted Free Writing Prospectus, as the case may be, and deemed to be incorporated therein by reference.

As used in this Agreement, “business day” shall mean a day on which The NASDAQ Stock Market (“NASDAQ”) is open for trading. The terms “herein,” “hereof,” “hereto,” “hereinafter” and similar terms, as used in this Agreement, shall in each case refer to this Agreement as a whole and not to any particular section, paragraph, sentence or other subdivision of this Agreement. The term “or,” as used herein, is not exclusive.

The Company and the Underwriters agree as follows:

1. Sale and Purchase. Upon the basis of the representations and warranties and subject to the terms and conditions herein set forth, the Company agrees to issue and sell to the respective Underwriters and each of the Underwriters, severally and not jointly, agrees to purchase from the Company the number of Firm Shares set forth opposite the name of such Underwriter in Schedule A hereto, subject to adjustment in accordance herewith, in each case at a purchase price of $20.04 per Share. The Company is advised by the Underwriters that the Underwriters intend (i) to make a public offering of their respective portions of the Firm Shares as soon after the effectiveness of this Agreement as in the Underwriters’ judgment is advisable and (ii) initially to offer the Firm Shares upon the terms set forth in the Prospectus. The Underwriters may from time to time increase or decrease the public offering price after the initial public offering to such extent as the Underwriters may determine.

In addition, the Company hereby grants to the several Underwriters the option to purchase, and upon the basis of the warranties and representations and subject to the terms and conditions herein set forth, the Underwriters shall have the right to purchase, severally and not jointly, from the Company, ratably in accordance with the number of Firm Shares to be purchased by each of them, all or a portion of the Additional Shares as may be necessary to cover over-allotments made in connection with the offering of the Firm Shares, at the same purchase price per share to be paid by the Underwriters to the Company for the Firm Shares. This option may be exercised by the Underwriters at any time and from time to time on or before the thirtieth day following the date hereof, by written notice to the Company. Such notice shall set forth the aggregate number of Additional Shares as to which the option is being exercised, and the date and time when the Additional Shares are to be delivered (such date and time being herein referred to as the “Additional Time of Purchase”); provided, however, that the Additional Time of Purchase shall not be earlier than the Time of Purchase (as defined below) nor earlier than the second business day after the date on which the option shall have been exercised nor later than the tenth business day after the date on which the option shall have been exercised.

2. Payment and Delivery. Payment of the purchase price for the Firm Shares shall be made to the Company by Federal Funds wire transfer against delivery of the certificates for the Firm Shares to the Underwriters through the facilities of The Depository Trust Company (“DTC”) for the respective accounts of the Underwriters. Such payment and delivery shall be made at 10:00 a.m., Boston time, on November 23, 2010 (the “Closing Date”) (unless another time shall be agreed to by the Underwriters and the Company). The time at which such payment and delivery are to be made is hereinafter sometimes called the “Time of Purchase.” Electronic transfer of the Firm Shares shall be made to the Underwriters at the Time of Purchase in such names and in such denominations as the Underwriters shall specify.

Payment of the purchase price for the Additional Shares shall be made at the Additional Time of Purchase in the same manner and at the same office as the payment for the Firm Shares. Electronic transfer of the Firm Shares shall be made to the Underwriters at the Time of Purchase in such names and in such denominations as the Underwriters shall specify. The Time of Purchase and the Additional Time of Purchase are sometimes referred to herein as the Closing Dates.

Deliveries of the documents described in Section 6 hereof with respect to the purchase of the Shares shall be made at the offices of Xxxxxxx Procter, LLP, Xxxxxxxx Xxxxx, Xxxxxx, Xxxxxxxxxxxxx 00000, at 9:00 A.M., Boston time, on the Closing Date.

3. Representations and Warranties of the Company. The Company represents and warrants to and agrees with each of the Underwriters that:

(a) the Registration Statement has heretofore become effective under the Act; no stop order of the Commission preventing or suspending the use of the Basic Prospectus, the Prospectus Supplement, the Prospectus or any Permitted Free Writing Prospectus, or the effectiveness of the Registration Statement, has been issued, and no proceedings for such purpose have been instituted or, to the Company’s knowledge, are contemplated by the Commission;

(b) the Registration Statement complied when it became effective, complies as of the date hereof and, as amended or supplemented, at the Time of Purchase and at all times during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, will comply, in all material respects, with the requirements of the Act; the conditions to the use of Form S-3 in connection with the offering and sale of the Shares as contemplated hereby have been satisfied; the Registration Statement meets, and the offering and sale of the Shares as contemplated hereby complies with, the requirements of Rule 415 under the Act; the Registration Statement did not, as of the Effective Time, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; the Basic Prospectus complied as of its date and the date it was filed with the Commission, complies as of the date hereof and, at the Time of Purchase and at all times during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, will comply, in all material respects, with the requirements of the Act; the Disclosure Package does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; each of the Prospectus Supplement and the Prospectus will comply, as of the date that it is filed with the Commission, the date of the Prospectus Supplement, the Time of Purchase and at all times during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, in all material respects, with the requirements of the Act (in the case of the Prospectus, including, without limitation, Section 10(a) of the Act); at no time during the period that begins on the earlier of the date of the Prospectus Supplement and the date the Prospectus Supplement is filed with the Commission and ends at the later of the Time of Purchase and the end of the period during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares did or will any Prospectus Supplement or the Prospectus, as then amended or supplemented, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; each Permitted Free Writing Prospectus does not conflict with the information contained in the Registration Statement, the Disclosure Package or the Prospectus, and at no time during the period that begins on the date of such Permitted Free Writing Prospectus and ends at the Time of Purchase did or will any Permitted Free Writing Prospectus include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company makes no representation or warranty in this Section 3(b) with respect to any statement contained in the Registration Statement, the Prospectus or any Permitted Free Writing Prospectus in reliance upon and in conformity with information concerning the Underwriters and furnished in writing by or on behalf of such Underwriters to the Company expressly for use in the Registration Statement, the Prospectus or such Permitted Free Writing Prospectus; each Incorporated Document, at the time such document was filed with the Commission or at the time such document became effective, as applicable, complied, in all material respects, with the requirements of the Exchange Act and did not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(c) prior to the execution of this Agreement, the Company has not, directly or indirectly, offered or sold any Shares by means of any “prospectus” (within the meaning of the Act) or used any “prospectus” (within the meaning of the Act) in connection with the offer or sale of the Shares, in each case other than the Basic Prospectus and the Permitted Free Writing Prospectuses, if any; the Company has not, directly or indirectly, prepared, used or referred to any Permitted Free Writing Prospectus except in compliance with Rules 164 and 433 under the Act; assuming that such Permitted Free Writing Prospectus is so sent or given after the Registration Statement was filed with the Commission (and after such Permitted Free Writing Prospectus was, if required pursuant to Rule 433(d) under the Act, filed with the Commission), the sending or giving, by any Underwriter, of any Permitted Free Writing Prospectus will satisfy the provisions of Rule 164 and Rule 433 (without reliance on subsections (b), (c) and (d) of Rule 164); the conditions set forth in one or more of subclauses (i) through (iv), inclusive, of Rule 433(b)(1) under the Act are satisfied, and the registration statement relating to the offering of the Shares contemplated hereby, as initially filed with the Commission, includes a prospectus that, other than by reason of Rule 433 or Rule 431 under the Act, satisfies the requirements of Section 10 of the Act; neither the Company nor the Underwriters are disqualified, by reason of subsection (f) or (g) of Rule 164 under the Act, from using, in connection with the offer and sale of the Shares, “free writing prospectuses” (as defined in Rule 405 under the Act) pursuant to Rules 164 and 433 under the Act; the Company is not an “ineligible issuer” (as defined in Rule 405 under the Act) as of the eligibility determination date for purposes of Rules 164 and 433 under the Act with respect to the offering of the Shares contemplated by the Registration Statement;

(d) the financial statements of the Company, together with the related notes, set forth or incorporated by reference, in the Registration Statement, the Disclosure Package and the Prospectus comply in all material respects with the requirements of the Act and fairly present the financial condition of the Company and its Subsidiaries (defined below) as of the dates indicated and the results of operations and changes in cash flows for the periods therein specified in conformity with generally accepted accounting principles in the United States consistently applied throughout the periods involved; and the supporting schedules included in the Registration Statement, the Disclosure Package and the Prospectus have been derived from the accounting records of the Company and its Subsidiaries and present fairly the information required to be stated therein. No schedules or other financial statements are required to be included in the Registration Statement, the Disclosure Package or the Prospectus. To the Company’s knowledge, Ernst & Young LLP, which has expressed its opinion with respect to the audited financial statements filed as a part of the Registration Statement and included in the Registration Statement, the Disclosure Package and the Prospectus, is (x) an independent public accounting firm within the meaning of the Act, (y) a registered public accounting firm (as defined in Section 2(a)(12) of the Xxxxxxxx-Xxxxx Act of 2002 (the “Xxxxxxxx-Xxxxx Act”)) and (z) in the performance of their work for the Company, not in violation of the auditor independence requirements of the Xxxxxxxx-Xxxxx Act. Except as described in the Disclosure Package and the Prospectus, there are no material off-balance sheet transactions, arrangements, obligations (including contingent obligations), or any other relationships with unconsolidated entities or other persons, that may have a material adverse current or, to the Company’s knowledge, future effect on the Company’s or its Subsidiaries’ financial condition, changes in financial condition, results of operations, liquidity, capital expenditures, capital resources or significant components of revenue or expenses;

(e) the Company has been duly organized and is validly existing as a corporation in good standing under the laws of the State of Delaware. The Company has full corporate power and authority to own its properties and conduct its business as currently being conducted and as described in the Registration Statement, the Disclosure Package and the Prospectus, and is duly qualified to do business as a foreign corporation in good standing in each jurisdiction in which it owns or leases real property or in which the conduct of its business makes such qualification necessary and in which the failure to so qualify might result in a material adverse change in the condition (financial or otherwise), business, prospects, property, operations or results of operations of the Company and its Subsidiaries, taken as a whole (“Material Adverse Change”). The Company has no subsidiaries (as defined under the Act) other than those listed on Exhibit 21.1 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2009 (collectively, the “Subsidiaries”); except as disclosed in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any, the Company owns, directly or indirectly, all of the issued and outstanding capital stock of each of the Subsidiaries; the Company does not own, directly or indirectly, any shares of stock or any other equity interests or long-term debt securities of any corporation, firm, partnership, joint venture, association or other entity; complete and correct copies of the charters and the bylaws or similar organizational documents of the Company and the Subsidiaries and all amendments thereto have been delivered to the Underwriters, and no changes therein will be made on or after the date hereof through and including the Time of Purchase; each Subsidiary has been incorporated and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, with full corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any; each Subsidiary is qualified to do business as a foreign corporation and is in good standing in each jurisdiction where the ownership or leasing of its properties or the conduct of its business requires such qualification, except where the failure to be so qualified and in good standing would not, individually or in the aggregate, result in a Material Adverse Change; all of the outstanding shares of capital stock of each of the Subsidiaries have been duly authorized and validly issued, are fully paid and non-assessable, have been issued in compliance with all applicable securities laws, were not issued in violation of any preemptive right, resale right, right of first refusal or similar right and are owned by the Company subject to no security interest, other encumbrance or adverse claims; no options, warrants or other rights to purchase, agreements or other obligations to issue or other rights to convert any obligation into shares of capital stock or ownership interests in the Subsidiaries are outstanding; the Company has no “significant subsidiary,” as that term is defined in Rule 1-02(w) of Regulation S-X under the Act, other than Medisystems Corporation, a Washington corporation;

(f) except as contemplated in the Registration Statement, the Disclosure Package and the Prospectus as of the date of effectiveness of the Registration Statement, the time of delivery of the Disclosure Package and the date of the Prospectus, respectively, subsequent to such respective dates, (a) neither the Company nor any of its Subsidiaries has incurred any material liabilities or obligations, direct or contingent, or entered into any material transactions, or declared or paid any dividends or made any distribution of any kind with respect to its capital stock; and (b) there has not been any change in the capital stock (other than a change in the number

of outstanding shares of Common Stock due to the issuance of shares upon the exercise of outstanding options, warrants or equity compensation awards), or any material change in the short term or long term debt, or any issuance of options, warrants, convertible securities or other rights to purchase the capital stock, of the Company or any of its Subsidiaries (other than issuances of options and equity compensation awards under the Company’s existing equity incentive plans), or any Material Adverse Change or any development that could reasonably be expected to result in a Material Adverse Change;

(g) except as set forth in the Disclosure Package and the Prospectus, there is not pending or, to the knowledge of the Company, threatened or contemplated, any action, suit or proceeding to which the Company or any of its Subsidiaries is a party or of which any property or assets of the Company or any of its Subsidiaries is the subject before or by any court or governmental agency, authority or body, or any arbitrator, which, individually or in the aggregate, could reasonably be expected to result in any Material Adverse Change. There are no current or pending legal, governmental or regulatory actions, suits or proceedings that are required to be described in the Registration Statement, the Disclosure Package and the Prospectus that have not been so described;

(h) there are no statutes, regulations, contracts or documents that are required to be described in the Registration Statement, the Disclosure Package and the Prospectus or to be filed as exhibits to the Registration Statement by the Act that have not been so described or filed;

(i) this Agreement has been duly authorized, executed and delivered by the Company, and constitutes a valid, legal and binding obligation of the Company, enforceable in accordance with its terms, except as rights to indemnity hereunder may be limited by federal or state securities laws and except as such enforceability may be limited by bankruptcy, insolvency, reorganization or similar laws affecting the rights of creditors generally and subject to general principles of equity. The execution, delivery and performance of this Agreement and the consummation of the transactions herein contemplated will not (A) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of the Subsidiaries pursuant to, any indenture, mortgage, deed of trust, loan agreement or other material agreement or instrument to which the Company or any of the Subsidiaries is a party or by which the Company or any of the Subsidiaries is bound or to which any of the property or assets of the Company or any of the Subsidiaries is subject except as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change, (B) result in any violation of the provisions of the charter or by-laws of the Company or any of the Subsidiaries or (C) result in the violation of any material law or statute or any material judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority. No consent, approval, authorization or order of, or filing with, any court or governmental agency or body is required for the execution, delivery and performance of this Agreement or for the consummation of the transactions contemplated hereby, including the issuance or sale of the Shares by the Company, except such as may be required under the Act or state securities or blue sky laws; and the Company has full corporate power and authority to enter into this Agreement and to consummate the transactions contemplated hereby including the authorization, issuance and sale of the Shares as contemplated by this Agreement;

(j) all of the issued and outstanding shares of capital stock of the Company, including the outstanding shares of Common Stock, are duly authorized and validly issued, fully paid and nonassessable, have been issued in compliance with all federal and state securities laws, were not issued in violation of or subject to any preemptive rights or other rights to subscribe for or purchase securities that have not been waived in writing (a copy of which has been delivered to counsel to the Underwriters); the Shares which may be sold hereunder by the Company have been duly authorized and, when issued, delivered and paid for in accordance with the terms of this Agreement, will have been validly issued and will be fully paid and nonassessable; and the capital stock of the Company, including the Common Stock, conforms to the description thereof in the Registration Statement, the Disclosure Package and the Prospectus. Except as otherwise described in the Registration Statement, the Disclosure Package and the Prospectus, there are no preemptive rights or other rights to subscribe for or to purchase, or any restriction upon the voting or transfer of, any shares of Common Stock pursuant to the Company’s charter, by laws or any agreement or other instrument to which the Company is a party or by which the Company is bound. Neither the filing of the Registration Statement nor the offering or sale of the Shares as contemplated by this Agreement gives rise to any rights for or relating to the registration of any shares of Common Stock or other Shares of the Company that have not been fully complied with or previously waived. Except as described or contemplated in the Registration Statement, the Disclosure Package and the Prospectus, there are no options, warrants, agreements, contracts or other rights in existence to purchase or acquire from the Company any shares of the capital stock of the Company. The Company has an authorized and outstanding capitalization as set forth in the Registration Statement, the Disclosure Package and the Prospectus. The description of the Company’s stock option, stock bonus and other stock plans or arrangements, and the options or other rights granted thereunder, set forth in the Disclosure Package and the Prospectus accurately and fairly presents the information required to be shown with respect to such plans, arrangements, options and rights;

(k) except as described in the Disclosure Package and the Prospectus, the Company and each Subsidiary possesses all material licenses, certificates, permits and other authorizations issued by, and has made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of its properties or the conduct of its business, except as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change; except as described in the Disclosure Package and the Prospectus, neither the Company nor any Subsidiary has received notice of any revocation or modification of any such license, certificate, permit or authorization or has any reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course; and the Company and each Subsidiary is in compliance with applicable federal, state, local and foreign laws, regulations, orders and decrees except as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change;

(l) the Company and each Subsidiary has good and marketable title to all property (whether real or personal) described in the Registration Statement, the Disclosure Package and the Prospectus as being owned by it, in each case free and clear of all liens, claims, security interests, other encumbrances or defects except as described in the Registration Statement, the Disclosure Package and the Prospectus, and except those that could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change. The property held under lease by the Company or any Subsidiary is held by it under valid, subsisting and enforceable leases with only such exceptions with respect to any particular lease as do not interfere in any material respect with the conduct of the business of the Company or such Subsidiary;

(m) the Company and the Subsidiaries own, possess, license or can acquire or license on reasonable terms, all Intellectual Property necessary for the conduct of the Company’s and the Subsidiaries’ business as now conducted or as described in the Registration Statement, the Disclosure Package and the Prospectus as expected to be conducted, except as such failure to own, possess, or acquire such rights would not result in a Material Adverse Change, or except as described in the Registration Statement, the Disclosure Package and the Prospectus. Except as set forth in the Registration Statement, the Disclosure Package and the Prospectus, (A) to the knowledge of the Company, there is no infringement, misappropriation or violation by third parties of any such Intellectual Property, except as such infringement, misappropriation or violation would not result in a Material Adverse Change; (B) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others challenging the Company’s or any of its Subsidiaries’ rights in or to any such Intellectual Property, and the Company is unaware of any facts which would form a reasonable basis for any such claim except for any claim as would not reasonably be expected to result in a Material Adverse Change; (C) the Intellectual Property owned by the Company and its Subsidiaries and to the knowledge of the Company, the Intellectual Property licensed to the Company and its Subsidiaries have not been adjudged invalid or unenforceable, in whole or in part, in any respect that would be material to the Company and there is no pending or threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property, and the Company is unaware of any facts which would form a reasonable basis for any such claim except for any claim as would not reasonably be expected to result in a Material Adverse Change; (D) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others that the Company or any of its Subsidiaries infringes, misappropriates or otherwise violates any Intellectual Property or other proprietary rights of others, neither the Company nor any of its Subsidiaries has received any written notice of such claim and the Company is unaware of any other fact which would form a reasonable basis for any such claim except for any claim as would not reasonably be expected to result in a Material Adverse Change; and (E) to the Company’s knowledge, no employee of the Company or any of its Subsidiaries is in or has ever been in violation of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or any of its Subsidiaries or actions undertaken by the employee while employed with the Company of any of its Subsidiaries except for any violation that would not reasonably be expected to result in a Material Adverse Change. “Intellectual Property” shall mean all patents, patent applications, trade and service marks, trade and service xxxx registrations, trade names, copyrights, licenses, inventions, trade secrets, technology, know-how and other intellectual property;

(n) neither the Company nor any of its Subsidiaries is (A) in the case of the Company, in violation of its charter or bylaws; (B) in the case of any Subsidiary, in violation of its charter or bylaws or similar organizational documents; (C) in breach of or otherwise in default, and no event has occurred which, with notice or lapse of time or both, would constitute such a default in the performance or observance of any term, covenant, obligation, agreement or condition

contained in any bond, debenture, note, indenture, loan agreement, mortgage, deed of trust or any other contract, lease or other instrument to which it is subject or by which it may be bound, or to which any of the material property or assets of the Company or any of its Subsidiaries is subject; or (D) in violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except in the case of (B), (C) and (D) above, as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change;

(o) the Company and each of its Subsidiaries has timely filed all federal, state, local and foreign income and franchise tax returns required to be filed (or have timely requested and received applicable extension therefor) and is not in default in the payment of any material taxes which were payable pursuant to said returns or any assessments with respect thereto, other than any which the Company or any of its Subsidiaries is contesting in good faith. There is no pending dispute with any taxing authority relating to any of such returns and the Company has no knowledge of any material proposed liability for any tax to be imposed upon the properties or assets of the Company or any of its Subsidiaries for which there is not an adequate reserve reflected in the Company’s financial statements included in the Registration Statement;

(p) the Company has not distributed and will not distribute any prospectus or other offering material in connection with the offering and sale of the Shares other than the Disclosure Package or the Prospectus or other materials permitted by the Act to be distributed by the Company; provided, however, that, except as set forth on Schedule B, the Company has not made and will not make any offer relating to the Shares that would constitute a “free writing prospectus” as defined in Rule 405 under the Securities Act;

(q) the Common Stock of the Company is registered and listed on The NASDAQ Global Market under the ticker symbol “NXTM.” The Company has not received any notice that it is not in compliance with the listing or maintenance requirements of NASDAQ. The Company believes that it is, and has no reason to believe that it will not in the foreseeable future continue to be, in material compliance with all such listing and maintenance requirements. Except as described in the Registration Statement, the Disclosure Package or the Prospectus, there are no affiliations among the Company’s directors and officers and members of the Financial Institution Regulatory Authority (“FINRA”). A Registration Statement relating to the Common Stock on Form 8-A or other applicable form under the Exchange Act has become effective;

(r) the Company maintains a system of internal accounting controls sufficient to provide reasonable assurances that (A) transactions are executed in accordance with management’s general or specific authorization; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles in the United States and to maintain accountability for assets; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as disclosed in the Registration Statement, in the Disclosure Package and in the Prospectus, the Company’s internal control over financial reporting is effective; and since the end of the latest audited fiscal year, there has been no change in the Company’s internal control over financial reporting (whether or not remediated) that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting;

(s) the Company’s board of directors has validly appointed an audit committee whose composition satisfies the applicable requirements of Rule 5605(c)(2) of the NASDAQ Marketplace Rules (the “NASD Rules”) and the Company’s board of directors and/or the audit committee has adopted a charter that satisfies the requirements of Rule 5605(c)(1) of the NASD Rules. Neither the Company’s board of directors nor the audit committee has been informed, nor is any director of the Company aware, of (A) any significant deficiencies in the design or operation of the Company’s internal controls which could adversely affect the Company’s ability to record, process, summarize and report financial data or any material weakness in the Company’s internal controls; or (B) any fraud, whether or not material, that involves management or other employees of the Company who have a significant role in the Company’s internal controls over financial reporting;

(t) no relationship, direct or indirect, exists between or among the Company and its Subsidiaries, on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company and its Subsidiaries, on the other hand, which is required to be described in the Registration Statement, the Disclosure Package and the Prospectus which is not so described. Neither the Company nor any of its Subsidiaries has, directly or indirectly, extended or maintained credit, or arranged for the extension of credit, or renewed an extension of credit, in the form of a personal loan to or for any of its directors or executive officers in violation of applicable laws, including Section 402 of the Xxxxxxxx-Xxxxx Act;

(u) except as described in the Registration Statement, the Disclosure Package and the Prospectus, the Company and each of its Subsidiaries: (A) is and at all times has been in compliance with all statutes, rules, regulations, or guidances applicable to Company or any of its Subsidiaries and the ownership, testing, development, manufacture, packaging, processing, use, distribution, marketing, labeling, promotion, sale, offer for sale, storage, import, export or disposal of any product manufactured or distributed by the Company or any of its Subsidiaries (“Applicable Laws”), except as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change; (B) has not received any Form 483 notice of adverse finding by the U.S. Food and Drug Administration (the “FDA”), untitled letter or other correspondence or notice from the FDA any other federal, state or foreign governmental authority having authority over the Company or any of its Subsidiaries (“Governmental Authority”) alleging or asserting material noncompliance with any Applicable Laws or any licenses, certificates, approvals, clearances, authorizations, permits and supplements or amendments thereto required by any such Applicable Laws (“Authorizations”); (C) possesses all material Authorizations and such Authorizations are valid and in full force and effect and is not in violation of any term of any such Authorizations except as could not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Change; (D) has not received notice of any claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any Governmental Authority or third party alleging that any product operation or activity is in violation of any Applicable Laws or Authorizations and has no knowledge that any such Governmental Authority or third party is considering any such claim, litigation, arbitration, action, suit, investigation or proceeding; (E) has not received notice that any Governmental Authority has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations and has no knowledge that any such

Governmental Authority is considering such action; and (F) has filed, obtained, maintained or submitted all material reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments as required by any Applicable Laws or Authorizations and that all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments were complete and correct in all material respects on the date filed (or were corrected or supplemented by a subsequent submission);

(v) the Company and each of its Subsidiaries (A) is in compliance with any and all applicable federal, state, local and foreign laws, rules, regulations, decisions and orders relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (collectively, “Environmental Laws”); (B) has received and is in compliance with all permits, licenses or other approvals required of it under applicable Environmental Laws to conduct its business; and (C) has not received notice of any actual or potential liability for the investigation or remediation of any disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants; except in any such case for any such failure to comply, or failure to receive required permits, licenses or approvals, or liability as would not, individually or in the aggregate, result in a Material Adverse Change;

(w) the Company and each of its Subsidiaries (A) is in compliance, in all material respects, with any and all applicable foreign, federal, state and local laws, rules, regulations, treaties, statutes and codes promulgated by any and all governmental authorities (including pursuant to the Occupational Health and Safety Act) relating to the protection of human health and safety in the workplace (“Occupational Laws”); (B) has received all material permits, licenses or other approvals required of it under applicable Occupational Laws to conduct its business as currently conducted; and (C) is in compliance, in all material respects, with all terms and conditions of such permit, license or approval. No action, proceeding, revocation proceeding, writ, injunction or claim is pending or, to the Company’s knowledge, threatened against the Company or any of its Subsidiaries relating to Occupational Laws that if determined adversely to the Company would result in a Material Adverse Change, and the Company does not have knowledge of any facts, circumstances or developments relating to its operations that could reasonably be expected to form the basis for or give rise to such actions, suits, investigations or proceedings;

(x) each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is maintained, administered or contributed to by the Company or any of its affiliates for employees or former employees of the Company and its affiliates has been maintained in material compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to, ERISA and the Internal Revenue Code of 1986, as amended (the “Code”). No prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, has occurred with respect to any such plan excluding transactions effected pursuant to a statutory or administrative exemption; and for each such plan that is subject to the funding rules of Section 412 of the Code or Section 302 of ERISA, no “accumulated funding deficiency” as defined in Section 412 of the Code has been incurred, whether or not waived, and the fair market value of the assets of each such plan (excluding for these purposes accrued but unpaid contributions) exceeds the present value of all benefits accrued under such plan determined using reasonable actuarial assumptions;

(y) except as set forth in the Registration Statement, the Disclosure Package and the Prospectus, neither the Company nor any of its Subsidiaries has granted rights to develop, manufacture, produce, assemble, distribute, license, market or sell its products to any other person that are material to the Company nor is it bound by any agreement that affects the Company’s or any Subsidiary’s exclusive right to develop, manufacture, produce, assemble, distribute, license, market or sell its products that is material to the Company;

(z) nothing has come to the attention of the Company that has caused the Company to believe that the statistical and market-related data included in the Registration Statement, the Disclosure Package and the Prospectus is not based on or derived from sources that are reliable and accurate in all material respects and the Company has obtained the written consent for the use of such data from such sources, to the extent required under the Act;

(aa) other than as contemplated by this Agreement, neither the Company nor any Subsidiary has incurred any liability for any finder’s or broker’s fee or agent’s commission in connection with the execution and delivery of this Agreement or the consummation of the transactions contemplated hereby;

(bb) neither the Company nor any of its affiliates is presently doing business with the government of Cuba or with any person or affiliate known to the Company to be located in Cuba;

(cc) the Company and each of its Subsidiaries carries, or is covered by, insurance issued by insurers of nationally recognized financial responsibility in such amounts and covering such risks as is adequate for the conduct of its business and the value of its properties and as is customary for companies engaged in similar businesses in similar industries; and neither the Company nor any of its Subsidiaries has (A) received notice from any insurer or agent of such insurer that capital improvements or other expenditures are required or necessary to be made in order to continue such insurance or (B) reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage at reasonable cost from similar insurers as may be necessary to continue its business. All such insurance is outstanding and duly in force on the date hereof;

(dd) neither the Company nor any of its Subsidiaries nor, to the best knowledge of the Company, any director, officer, agent, employee or other person associated with or acting on behalf of the Company or any of its Subsidiaries has (A) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (B) made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; (C) violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977; or (D) made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment;

(ee) neither the Company nor any of its Subsidiaries is and, after giving effect to the offering and sale of the Shares, will not be an “investment company,” as such term is defined in the Investment Company Act of 1940, as amended;

(ff) the conditions for use of Form S-3, set forth in the General Instructions thereto, including General Instruction I.D., have been satisfied;

(gg) the Company and its Subsidiaries are in compliance with all applicable provisions of the Xxxxxxxx-Xxxxx Act and the rules and regulations of the Commission thereunder;

(hh) the Company and its Subsidiaries have established and maintain disclosure controls and procedures (as defined in Rules 13a-14 and 15d-14 under the Exchange Act) and such controls and procedures are effective in ensuring that material information relating to the Company and its Subsidiaries is made known to the principal executive officer and the principal financial officer. The Company and its Subsidiaries have utilized such controls and procedures in preparing and evaluating the disclosures in the Registration Statement, in the Disclosure Package and in the Prospectus;

(ii) the Company has obtained for the benefit of the Underwriters the agreement, in the form set forth as Exhibit A hereto, of each of its directors and “officers” (within the meaning of Rule 16a-1(f) under the Exchange Act) (each a “Lock-Up Agreement” and collectively, the “Lock-Up Agreements”);

(jj) neither the Company nor any of the Subsidiaries is engaged in any unfair labor practice; except for matters which would not, individually or in the aggregate, result in a Material Adverse Change, (i) there is (A) no unfair labor practice complaint pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries before the National Labor Relations Board, and no grievance or arbitration proceeding arising out of or under collective bargaining agreements is pending or, to the Company’s knowledge, threatened, (B) no strike, labor dispute, slowdown or stoppage pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries and (C) no union representation dispute currently existing concerning the employees of the Company or any of the Subsidiaries, (ii) to the Company’s knowledge, no union organizing activities are currently taking place concerning the employees of the Company or any of the Subsidiaries and (iii) there has been no violation of any federal, state, local or foreign law relating to discrimination in the hiring, promotion or pay of employees, any applicable wage or hour laws, any provision of the Worker Adjustment and Retraining Notification Act of 1988, as amended (“WARN Act”) or the WARN Act’s state, foreign or local equivalent, or any provision of the Employee Retirement Income Security Act of 1974 or the rules and regulations promulgated thereunder concerning the employees of the Company or any of the Subsidiaries;

(kk) each “forward-looking statement” (within the meaning of Section 27A of the Act or Section 21E of the Exchange Act) contained or incorporated by reference in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any, has been made or reaffirmed with a reasonable basis and in good faith;

(ll) the operations of the Company and the Subsidiaries are and have been conducted at all times in material compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any

governmental agency (collectively, the “Money Laundering Laws”); and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator or non-governmental authority involving the Company or any of the Subsidiaries with respect to the Money Laundering Laws is pending or, to the Company’s knowledge, threatened;

(mm) neither the Company nor any of the Subsidiaries nor, to the knowledge of the Company, any director, officer, agent, employee or affiliate of the Company or any of the Subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of the offering of the Shares contemplated hereby, or lend, contribute or otherwise make available such proceeds to any Subsidiary, joint venture partner or other person or entity for the purpose of financing the activities of any person known by the Company to be currently subject to any U.S. sanctions administered by OFAC;

(nn) no Subsidiary is currently prohibited, directly or indirectly, from paying any dividends to the Company, from making any other distribution on such Subsidiary’s capital stock, from repaying to the Company any loans or advances to such Subsidiary from the Company or from transferring any of such Subsidiary’s property or assets to the Company or any other Subsidiary of the Company, except as described in the Registration Statement (excluding the exhibits thereto) and the Prospectus;

(oo) the Company has not received any notice from NASDAQ regarding the delisting of the Common Stock from NASDAQ;

(pp) neither the Company nor any of the Subsidiaries nor any of their respective directors, officers or, to the knowledge of the Company, any of their affiliates or controlling persons has taken, directly or indirectly, any action designed, or which has constituted or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares.

(qq) In addition, any certificate signed by any officer of the Company or any of the Subsidiaries and delivered to the Underwriters or counsel for the Underwriters in connection with the offering of the Shares shall be deemed to be a representation and warranty by the Company, as to matters covered thereby, to each Underwriter.

4. Certain Covenants of the Company. The Company hereby agrees:

(a) to furnish such information as may be required and otherwise to cooperate in qualifying the Shares for offering and sale under the securities or blue sky laws of such states or other jurisdictions as the Underwriters may designate and to maintain such qualifications in effect so long as the Underwriters may request for the distribution of the Shares; provided, however, that the Company shall not be required to qualify as a foreign corporation or to consent to the service of process under the laws of any such jurisdiction (except service of process with respect to the offering and sale of the Shares); and to promptly advise the Underwriters of the receipt by the Company of any notification with respect to the suspension of the qualification of the Shares for offer or sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose;

(b) to make available to the Underwriters in Boston, as soon as practicable after this Agreement becomes effective, and thereafter from time to time to furnish to the Underwriters, as many copies of the Prospectus (or of the Prospectus as amended or supplemented if the Company shall have made any amendments or supplements thereto after the Effective Time) as the Underwriters may reasonably request for the purposes contemplated by the Act; in case any Underwriter is required to deliver (whether physically or through compliance with Rule 172 under the Act or any similar rule), in connection with the sale of the Shares, a prospectus after the nine-month period referred to in Section 10(a)(3) of the Act, or after the time a post-effective amendment to the Registration Statement is required pursuant to Item 512(a) of Regulation S-K under the Act, the Company will prepare, at its expense, promptly upon request such amendment or amendments to the Registration Statement and the Prospectus as may be necessary to permit compliance with the requirements of Section 10(a)(3) of the Act or Item 512(a) of Regulation S-K under the Act, as the case may be;

(c) if, at the time this Agreement is executed and delivered, it is necessary or appropriate for a post-effective amendment to the Registration Statement to be filed with the Commission and become effective before the Shares may be sold, the Company will use its best efforts to cause such post-effective amendment to be filed and become effective; and the Company will advise the Underwriters promptly and, if requested by the Underwriters, will confirm such advice in writing, (i) when such post-effective amendment has become effective, and (ii) if Rule 430A under the Act is used, when the Prospectus is filed with the Commission pursuant to Rule 424(b) under the Act (which the Company agrees to file in a timely manner in accordance with such Rules);

(d) if, at any time during the period when a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, the Registration Statement shall cease to comply with the requirements of the Act with respect to eligibility for the use of the form on which the Registration Statement was filed with the Commission, to (i) promptly notify the Underwriters, (ii) promptly file with the Commission a new registration statement under the Act, relating to the Shares, or a post-effective amendment to the Registration Statement, which new registration statement or post-effective amendment shall comply with the requirements of the Act and shall be in a form satisfactory to the Underwriters, (iii) use its best efforts to cause such new registration statement or post-effective amendment to become effective under the Act as soon as practicable, (iv) promptly notify the Underwriters of such effectiveness and (v) take all other action necessary or appropriate to permit the public offering and sale of the Shares to continue as contemplated in the Prospectus; all references herein to the Registration Statement shall be deemed to include each such new registration statement or post-effective amendment, if any;

(e) if the third anniversary of the initial effective date of the Registration Statement shall occur at any time during the period when a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, to file with the Commission, prior to such third anniversary, a new registration statement under the Act relating to the Shares, which new registration statement shall comply with the requirements of the Act and shall be in a form satisfactory to the Underwriters; the Company shall use its best efforts to cause such new registration statement to become effective under the Act as soon as practicable, but in any event

within 180 days after such third anniversary and promptly notify the Underwriters of such effectiveness; the Company shall take all other action necessary or appropriate to permit the public offering and sale of the Shares to continue as contemplated in the Prospectus; all references herein to the Registration Statement shall be deemed to include each such new registration statement, if any;

(f) to advise the Underwriters promptly, confirming such advice in writing, of any request by the Commission for amendments or supplements to the Registration Statement, the Prospectus or any Permitted Free Writing Prospectus or for additional information with respect thereto, or of notice of institution of proceedings for, or the entry of a stop order, suspending the effectiveness of the Registration Statement and, if the Commission should enter a stop order suspending the effectiveness of the Registration Statement, to use its reasonable best efforts to obtain the lifting or removal of such order as soon as possible; to advise the Underwriters promptly of any proposal to amend or supplement the Registration Statement or the Prospectus, and to provide the Underwriters and Underwriters’ counsel copies of any such documents for review and comment a reasonable amount of time prior to any proposed filing and to file no such amendment or supplement to which the Underwriters shall object in writing;

(g) subject to Section 4(e) hereof, to file promptly all reports and documents and any preliminary or definitive proxy or information statement required to be filed by the Company with the Commission in order to comply with the Exchange Act for so long as a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares; and to provide the Underwriters, for the Underwriters’ review and comment, with a copy of such reports and statements and other documents to be filed by the Company pursuant to Section 13, 14 or 15(d) of the Exchange Act during such period a reasonable amount of time prior to any proposed filing, and to file no such report, statement or document to which the Underwriters shall have objected in writing; and to promptly notify the Underwriters of such filing;

(h) to advise the Underwriters promptly of the happening of any event within the period during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, which event could require the making of any change in the Prospectus then being used so that the Prospectus would not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading, and to advise the Underwriters promptly if, during such period, it shall become necessary to amend or supplement the Prospectus to cause the Prospectus to comply with the requirements of the Act, and, in each case, during such time, subject to Section 4(e) hereof, to prepare and furnish, at the Company’s expense, to the Underwriters promptly such amendments or supplements to such Prospectus as may be necessary to reflect any such change or to effect such compliance;

(i) to make generally available to its security holders, and to deliver to the Underwriters, as soon as practicable but in no event later then 15 months after the end of the Company’s current fiscal quarter, an earnings statement of the Company which will satisfy the provisions of Section 11(a) of the Act covering a period of twelve months which will satisfy the provisions of Section 11(a) of the Act and Rule 158 under the Act;

(j) to furnish to the Underwriters two copies of the Registration Statement, as initially filed with the Commission, and of all amendments thereto (including all exhibits thereto and documents incorporated by reference therein);

(k) to furnish to the Underwriters as early as practicable prior to the Time of Purchase, but not later than one business day prior thereto, a copy of the latest available unaudited interim and monthly consolidated financial statements, if any, of the Company and the Subsidiaries which have been read by the Company’s independent registered public accountants, as stated in their letter to be furnished pursuant to Section 6(c) hereof;

(l) to pay all costs, expenses, fees and taxes in connection with (i) the preparation and filing of the Registration Statement, each Basic Prospectus, the Prospectus Supplement, the Prospectus, each Permitted Free Writing Prospectus and any amendments or supplements thereto, and the printing and furnishing of copies of each thereof to the Underwriters and to dealers (including costs of mailing and shipment), (ii) the registration, issue, sale and delivery of the Shares including any stock or transfer taxes and stamp or similar duties payable upon the sale, issuance or delivery of the Shares to the Underwriters, (iii) the producing, word processing and/or printing of this Agreement, any agreement among underwriters, any dealer agreements, any powers of attorney and any closing documents (including compilations thereof) and the reproduction and/or printing and furnishing of copies of each thereof to the Underwriters and (except closing documents) to dealers (including costs of mailing and shipment), (iv) the qualification of the Shares for offering and sale under state or foreign laws and the determination of their eligibility for investment under state or foreign law (including the legal fees and filing fees and other disbursements of counsel for the Underwriters) and the printing and furnishing of copies of any blue sky surveys or legal investment surveys to the Underwriters and to dealers, (v) any listing of the Shares on any securities exchange or qualification of the Shares for quotation on NASDAQ, (vi) any filing for review of the public offering of the Shares by FINRA, including the legal fees and filing fees and other disbursements of counsel to the Underwriters relating to FINRA matters, (vii) the fees and disbursements of any transfer agent or registrar for the Shares, (viii) the costs and expenses of the Company relating to presentations or meetings undertaken in connection with the marketing of the offering and sale of the Shares to prospective investors and the Underwriters’ sales forces, including, without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations, travel, lodging and other expenses incurred by the officers of the Company and any such consultants, and the cost of any aircraft chartered in connection with the road show, (ix) the performance of the Company’s other obligations hereunder and (x) all other costs and expenses of the Underwriters incident to the performance of their obligations hereunder not otherwise specifically provided for herein and the reasonable fees and expenses of the Underwriters’ legal counsel; provided however such costs and expenses provided for in this subsection (x) and subsection (vi) above shall not exceed $80,000;

(m) to comply with Rule 433(d) under the Act (without reliance on Rule 164(b) under the Act) and with Rule 433(g) under the Act;

(n) beginning on the date hereof and ending on, and including, the date that is 75 days after the date of the Prospectus Supplement (the “Lock-Up Period”), without the prior written consent of the Underwriters, not to directly or indirectly, offer for sale, sell, contract to sell, pledge, grant any option for the sale of, or otherwise issue or dispose of, directly or indirectly (or publicly disclose the intention to make any such offer, sale, pledge, grant, issuance or other disposition), any Common Stock or any securities convertible into or exchangeable for, or any options or rights to purchase or acquire, Common Stock, except (A) to the Underwriters pursuant to this Agreement, (B) to directors, employees or consultants of the Company pursuant to the Company’s 1999 Stock Option and Grant Plan, the Company’s 2005 Stock Incentive Plan or the Company’s 2005 Employee Stock Purchase Plan and (C) upon exercise, vesting or conversion of securities and equity awards outstanding as of the date hereof. Notwithstanding the foregoing, the Underwriters shall not unreasonably withhold their consent for the proposed issuance during the Lock-Up Period of Common Stock or any securities convertible into or exchangeable for, or any options or rights to purchase or acquire, Common Stock, if such proposed issuance is in connection with an acquisition, license, strategic collaboration or similar transaction, the purpose of which is other than raising capital for the Company. The Company agrees not to accelerate the vesting of any option or warrant or the lapse of any repurchase right prior to the expiration of the Lock-Up Period except for acceleration pursuant to change of control agreements in existence as of the date of this Agreement;

(o) prior to the Time of Purchase to issue no press release or other communication directly or indirectly and hold no press conferences with respect to the Company or any Subsidiary, the financial condition, results of operations, business, properties, assets, or liabilities of the Company or any Subsidiary, or the offering of the Shares, without the Underwriters’ prior consent except as required by law or the listing requirements of NASDAQ;

(p) not, at any time at or after the execution of this Agreement, to, directly or indirectly, offer or sell any Shares by means of any “prospectus” (within the meaning of the Act), or use any “prospectus” (within the meaning of the Act) in connection with the offer or sale of the Shares, in each case other than the Prospectus;

(q) not to, and to cause the Subsidiaries not to, take, directly or indirectly, any action designed, or which will constitute, or has constituted, or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares;

(r) to use its best efforts to cause the Shares to be listed on NASDAQ and to maintain the listing of the Common Stock for quotation on NASDAQ;

(s) to maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar for the Common Stock;

(t) to use the net proceeds received by it from the sale of the Shares pursuant to this Agreement in the manner specified in the Prospectus Supplement under the caption “Use of Proceeds”; and

(u) that, without the prior consent of the Underwriters, it has not made and will not make any offer relating to the Shares that would constitute a “free writing prospectus” (as defined in Rule 405 under the Act); the Company has complied and will comply with the requirements of Rule 433 under the Act applicable to any Permitted Free Writing Prospectus,

including timely filing with the Commission or retention where required and legending; and the Company agrees that if at any time following issuance of any Permitted Free Writing Prospectus any event occurred or occurs as a result of which such Permitted Free Writing Prospectus would conflict with the information in the Registration Statement, the Disclosure Package or the Prospectus or would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading, the Company will give prompt notice thereof to the Underwriters and, if requested by the Underwriters, will prepare and furnish without charge to the Underwriters a Permitted Free Writing Prospectus or other document which will correct such conflict, statement or omission.

5. Reimbursement of the Underwriter’s Expenses. If the Shares are not delivered to the Underwriters for any reason other than the default of the Underwriters in its or their respective obligations hereunder, the Company shall, in addition to paying the amounts described in Section 4(l) hereof, reimburse the Underwriters for all of their reasonable out-of-pocket expenses, including the reasonable fees and disbursements of their counsel.

6. Conditions of the Underwriters’ Obligations. The several obligations of the Underwriters hereunder are subject to the accuracy of the representations and warranties on the part of the Company on the date hereof, at the Time of Purchase, the performance by the Company of its obligations hereunder and to the following additional conditions precedent:

(a) The Company shall furnish to the Underwriters at the Time of Purchase an opinion and negative assurance statement of Xxxxx Lovells US LLP, counsel for the Company, addressed to the Underwriters, and dated the Time of Purchase, in form and substance satisfactory to the Underwriters, as to the matters set forth in Exhibit B hereto.

(b) The Company shall furnish to the Underwriters at the Time of Purchase an opinion of Miles & Stockbridge, P.C., special intellectual property counsel for the Company, addressed to the Underwriters, and dated the Time of Purchase, in form and substance satisfactory to the Underwriters, as to the matters set forth in Exhibit C hereto.

(c) The Underwriters shall have received from Ernst & Young LLP letters dated, respectively, the date of this Agreement and the Time of Purchase and addressed to the Underwriters in the forms satisfactory to the Underwriters, which letters shall cover the various financial disclosures contained in the Registration Statement and the Prospectus.

(d) The Underwriters shall have received at the Time of Purchase, the favorable opinion of Xxxxxxx Procter LLP, counsel for the Underwriters, dated the Time of Purchase, in form and substance reasonably satisfactory to the Underwriters.

(e) No Prospectus or amendment or supplement to the Registration Statement or the Prospectus shall have been filed to which the Underwriters shall have objected in writing.

(f) The Prospectus Supplement shall have been filed with the Commission pursuant to Rule 424(b) under the Act at or before 5:30 P.M., Boston time, on the second full business day after the date of this Agreement (or such earlier time as may be required under the Act).

(g) Prior to and at the Time of Purchase, (i) no stop order with respect to the effectiveness of the Registration Statement shall have been issued under the Act or proceedings initiated under Section 8(d) or 8(e) of the Act; (ii) the Registration Statement and all amendments thereto shall not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; (iii) neither the Prospectus nor amendment or supplement thereto shall include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading; (iv) neither the Disclosure Package, nor any amendment or supplement thereto, shall include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading; and (v) none of the Permitted Free Writing Prospectuses, if any, shall include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading.

(h) The Company will, at the Time of Purchase deliver to the Underwriters a certificate of its Chief Executive Officer and its Chief Financial Officer, dated the Time of Purchase, in a form satisfactory to the Underwriters.

(i) The Underwriters shall have received each of the signed Lock-Up Agreements referred to in Section 3(jj) hereof, and each such Lock-Up Agreement shall be in full force and effect at the Time of Purchase.

(j) The Company shall have furnished to the Underwriters such other documents and certificates as to the accuracy and completeness of any statement in the Registration Statement, the Prospectus or any Permitted Free Writing Prospectus as of the Time of Purchase as the Underwriters may reasonably request.

(k) The Shares shall have been approved for listing on NASDAQ, subject only to notice of issuance at or prior to the Time of Purchase.

(l) FINRA shall not have raised any objection with respect to the fairness or reasonableness of the underwriting, or other arrangements of the transactions, contemplated hereby.

7. Effective Date of Agreement; Termination. This Agreement shall become effective when the parties hereto have executed and delivered this Agreement.

The obligations of the several Underwriters hereunder shall be subject to termination in the absolute discretion of Canaccord Genuity Inc., if (1) since the time of execution of this Agreement or the earlier respective dates as of which information is given in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any, there has been any change or any development involving a prospective change in the business, properties, management, financial condition or results of operations of the Company and the Subsidiaries taken as a whole, the effect of which change or development is, in the sole judgment of Canaccord Genuity Inc., so material and adverse as to make it impractical or inadvisable to proceed with the public offering or the delivery of the Shares on the terms and in the manner

contemplated in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any, or (2) since the time of execution of this Agreement, there shall have occurred: (A) a suspension or material limitation in trading in securities generally on NASDAQ or the New York Stock Exchange; (B) a suspension or material limitation in trading in the Company’s securities on NASDAQ; (C) a general moratorium on commercial banking activities declared by either federal or New York State authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States; (D) an outbreak or escalation of hostilities or acts of terrorism involving the United States or a declaration by the United States of a national emergency or war; or (E) any other calamity or crisis or any change in financial, political or economic conditions in the United States or elsewhere, if the effect of any such event specified in clause (D) or (E), in the sole judgment of Canaccord Genuity Inc., makes it impractical or inadvisable to proceed with the public offering or the delivery of the Shares on the terms and in the manner contemplated in the Registration Statement, the Prospectus and the Permitted Free Writing Prospectuses, if any.

If Canaccord Genuity Inc. elects to terminate this Agreement as provided in this Section 7, the Company shall be notified promptly in writing.

If the sale to the Underwriters of the Shares, as contemplated by this Agreement, is not carried out by the Underwriters for any reason permitted under this Agreement, or if such sale is not carried out because the Company shall be unable to comply with any of the terms of this Agreement, the Company shall not be under any obligation or liability under this Agreement (except to the extent provided in Sections 4(l), 5 and 9 hereof), and the Underwriters shall be under no obligation or liability to the Company under this Agreement (except to the extent provided in Section 9 hereof) or to one another hereunder.

8. Indemnity and Contribution.

(a) The Company agrees to indemnify, defend and hold harmless the Underwriters, its partners, directors and officers, any person who controls the Underwriters within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons, from and against any loss, damage, expense, liability or claim (including the reasonable cost of investigation) which, jointly or severally, the Underwriters or any such person may incur under the Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company) or arises out of or is based upon any omission or alleged omission to state a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning the Underwriters furnished in writing by or on behalf of the Underwriters through the Underwriters to the Company expressly for use in, the Registration Statement or arises out of or is based upon any omission or alleged omission to state a material fact in the Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading or (ii) any

untrue statement or alleged untrue statement of a material fact included in any Prospectus (the term Prospectus for the purpose of this Section 9 being deemed to include any Basic Prospectus, the Prospectus Supplement, the Prospectus and any amendments or supplements to the foregoing), in any Permitted Free Writing Prospectus, in any “issuer information” (as defined in Rule 433 under the Act) of the Company or in any Prospectus together with any combination of one or more of the Permitted Free Writing Prospectuses, if any, or arises out of or is based upon any omission or alleged omission to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, except, with respect to such Prospectus or Permitted Free Writing Prospectus, insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning the Underwriters furnished in writing by or on behalf of the Underwriters through the Underwriters to the Company expressly for use in, such Prospectus or Permitted Free Writing Prospectus or arises out of or is based upon any omission or alleged omission to state a material fact in such Prospectus or Permitted Free Writing Prospectus in connection with such information, which material fact was not contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading.

(b) The Underwriters agree to indemnify, defend and hold harmless the Company, its directors and officers, and any person who controls the Company within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons, from and against any loss, damage, expense, liability or claim (including the reasonable cost of investigation) which, jointly or severally, the Company or any such person may incur under the Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning the Underwriters furnished in writing by or on behalf of the Underwriters to the Company expressly for use in, the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company), or arises out of or is based upon any omission or alleged omission to state a material fact in such Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading or (ii) any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning the Underwriters furnished in writing by or on behalf of the Underwriters through the Underwriters to the Company expressly for use in, a Prospectus or a Permitted Free Writing Prospectus, or arises out of or is based upon any omission or alleged omission to state a material fact in such Prospectus or Permitted Free Writing Prospectus in connection with such information, which material fact was not contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading.

(c) If any action, suit or proceeding (each, a “Proceeding”) is brought against a person (an “indemnified party”) in respect of which indemnity may be sought against the Company or the Underwriters (as applicable, the “indemnifying party”) pursuant to subsection (a) or (b), respectively, of this Section 9, such indemnified party shall promptly notify such

indemnifying party in writing of the institution of such Proceeding and such indemnifying party shall assume the defense of such Proceeding, including the employment of counsel reasonably satisfactory to such indemnified party and payment of all fees and expenses; provided, however, that the omission to so notify such indemnifying party shall not relieve such indemnifying party from any liability which such indemnifying party may have to any indemnified party or otherwise. The indemnified party or parties shall have the right to employ its or their own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of such indemnified party or parties unless the employment of such counsel shall have been authorized in writing by the indemnifying party in connection with the defense of such Proceeding or the indemnifying party shall not have, within a reasonable period of time in light of the circumstances, employed counsel to defend such Proceeding or such indemnified party or parties shall have reasonably concluded that there may be defenses available to it or them which are different from, additional to or in conflict with those available to such indemnifying party (in which case such indemnifying party shall not have the right to direct the defense of such Proceeding on behalf of the indemnified party or parties), in any of which events such fees and expenses shall be borne by such indemnifying party and paid as incurred (it being understood, however, that such indemnifying party shall not be liable for the expenses of more than one separate counsel (in addition to any local counsel) in any one Proceeding or series of related Proceedings in the same jurisdiction representing the indemnified parties who are parties to such Proceeding). The indemnifying party shall not be liable for any settlement of any Proceeding effected without its written consent, such consent not to be unreasonably withheld, but, if settled with its written consent, such indemnifying party agrees to indemnify and hold harmless the indemnified party or parties from and against any loss or liability by reason of such settlement. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by the second sentence of this Section 9(c), then the indemnifying party agrees that it shall be liable for any settlement of any Proceeding effected without its written consent if (i) such settlement is entered into more than 60 business days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall not have fully reimbursed the indemnified party in accordance with such request prior to the date of such settlement and (iii) such indemnified party shall have given the indemnifying party at least 30 days’ prior notice of its intention to settle. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened Proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such Proceeding and does not include an admission of fault or culpability or a failure to act by or on behalf of such indemnified party.

(d) If the indemnification provided for in this Section 9 is unavailable to an indemnified party under subsections (a) and (b) of this Section 9 or insufficient to hold an indemnified party harmless in respect of any losses, damages, expenses, liabilities or claims referred to therein, then each applicable indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, damages, expenses, liabilities or claims (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Shares or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above

but also the relative fault of the Company on the one hand and of the Underwriters on the other in connection with the statements or omissions which resulted in such losses, damages, expenses, liabilities or claims, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same respective proportions as the total proceeds from the offering (net of underwriting discounts and commissions but before deducting expenses) received by the Company, and the total underwriting discounts and commissions received by the Underwriters, bear to the aggregate public offering price of the Shares. The relative fault of the Company on the one hand and of the Underwriters on the other shall be determined by reference to, among other things, whether the untrue statement or alleged untrue statement of a material fact or omission or alleged omission relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The amount paid or payable by a party as a result of the losses, damages, expenses, liabilities and claims referred to in this subsection shall be deemed to include any legal or other fees or expenses reasonably incurred by such party in connection with investigating, preparing to defend or defending any Proceeding.

(e) The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 9 were determined by pro rata allocation or by any other method of allocation that does not take account of the equitable considerations referred to in subsection (d) above. Notwithstanding the provisions of this Section 9, the Underwriters shall not be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by such Underwriter and distributed to the public were offered to the public exceeds the amount of any damage which such Underwriter has otherwise been required to pay by reason of such untrue statement or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 9 are several in proportion to their respective underwriting commitments and not joint.

(f) The indemnity and contribution agreements contained in this Section 9 and the covenants, warranties and representations of the Company contained in this Agreement shall remain in full force and effect regardless of any investigation made by or on behalf of any Underwriter, its partners, directors or officers or any person (including each partner, director or officer of such person) who controls any Underwriter within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, or by or on behalf of the Company, its directors or officers or any person who controls the Company within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and shall survive any termination of this Agreement or the issuance and delivery of the Shares. The Company and each Underwriter agree promptly to notify each other of the commencement of any Proceeding against it and, in the case of the Company, against any of the Company’s officers or directors in connection with the issuance and sale of the Shares, or in connection with the Registration Statement, any Basic Prospectus, the Prospectus or any Permitted Free Writing Prospectus.

9. Notices. Except as otherwise herein provided, all statements, requests, notices and agreements shall be in writing or facsimile and, if to the Underwriters, shall be sufficient in all respects if delivered or sent to Canaccord Genuity Inc., 00 Xxxx Xxxxxx, 00xx Xxxxx, Xxxxxx, XX 00000, Attention: Syndicate Department (fax no.: 000-000-0000) with a copy (which shall not constitute notice) to Xxxxxxx Procter LLP, Exchange Place, Boston, MA 02109, Attention: Xxxxxxxx Xxxxx and Xxxx Xxxx (fax no.: 000-000-0000); and if to the Company, shall be sufficient in all respects if delivered or sent to the Company at the offices of the Company at 000 X. Xxxxx Xxxxxx, 0^xx Xxxxx, Xxxxxxxx, XX, 00000, Attention: Xxxxxx Xxxx, General Counsel (fax no.: 000-000-0000) with a copy (which shall not constitute notice) to Xxxxx Lovells US LLP, 000 Xxxxxxxxxxxxx Xxxxx, Xxxxx 0000, Xxxxxxxxx, XX, Attention: Xxxxxxx Xxxxxx (fax no.: 000-000-0000).

In accordance with the requirements of the USA Patriot Act (Title III of Pub. L. 107-56 (signed into law October 26, 2001)), the underwriters are required to obtain, verify and record information that identifies their respective clients, including the Company, which information may include the name and address of their respective clients, as well as other information that will allow the underwriters to properly identify their respective clients.

10. Governing Law; Construction. This Agreement and any claim, counterclaim or dispute of any kind or nature whatsoever arising out of or in any way relating to this Agreement (“Claim”), directly or indirectly, shall be governed by, and construed in accordance with, the laws of the State of New York. The section headings in this Agreement have been inserted as a matter of convenience of reference and are not a part of this Agreement.

11. Submission to Jurisdiction. Except as set forth below, no Claim may be commenced, prosecuted or continued in any court other than the courts of the Commonwealth of Massachusetts or in the United States District Court located in the Commonwealth of Massachusetts, which courts shall have jurisdiction over the adjudication of such matters, and the Company consents to the jurisdiction of such courts and personal service with respect thereto. The Company hereby consents to personal jurisdiction, service and venue in any court in which any Claim arising out of or in any way relating to this Agreement is brought by any third party against any Underwriter or any indemnified party. Each Underwriter and the Company (on its behalf and, to the extent permitted by applicable law, on behalf of its shareholders and affiliates) waives all right to trial by jury in any action, proceeding or counterclaim (whether based upon contract, tort or otherwise) in any way arising out of or relating to this Agreement. The Company agrees that a final judgment in any such action, proceeding or counterclaim brought in any such court shall be conclusive and binding upon the Company and may be enforced in any other courts to the jurisdiction of which the Company or is or may be subject, by suit upon such judgment.

12. Parties at Interest. The Agreement herein set forth has been and is made solely for the benefit of the Underwriters and the Company and to the extent provided in Section 9 hereof the controlling persons, partners, directors and officers referred to in such Section 9, and their respective successors, assigns, heirs, personal representatives and executors and administrators. No other person, partnership, association or corporation (including a purchaser, as such purchaser, from any of the Underwriters) shall acquire or have any right under or by virtue of this Agreement.

13. No Fiduciary Relationship. The Company hereby acknowledges that the Underwriters are acting solely as underwriters in connection with the purchase and sale of the Company’s securities. The Company further acknowledges that the Underwriters are acting pursuant to a contractual relationship created solely by this Agreement entered into on an arm’s length basis, and in no event do the parties intend that the Underwriters act or be responsible as a fiduciary to the Company, its management, shareholders or creditors or any other person in connection with any activity that the Underwriters may undertake or have undertaken in furtherance of the purchase and sale of the Company’s securities, either before or after the date hereof. The Underwriters hereby expressly disclaim any fiduciary or similar obligations to the Company, either in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions, and the Company hereby confirms its understanding and agreement to that effect. The Company and the Underwriters agree that they are each responsible for making their own independent judgments with respect to any such transactions and that any opinions or views expressed by the Underwriters to the Company regarding such transactions, including, but not limited to, any opinions or views with respect to the price or market for the Company’s securities, do not constitute advice or recommendations to the Company. The Company hereby waives and releases, to the fullest extent permitted by law, any claims that the Company may have against the Underwriters with respect to any breach or alleged breach of any fiduciary or similar duty to the Company in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions.

14. Counterparts. This Agreement may be signed by the parties in one or more counterparts which together shall constitute one and the same agreement among the parties.

15. Successors and Assigns. This Agreement shall be binding upon the Underwriters and the Company and their successors and assigns and any successor or assign of any substantial portion of the Company’s and any of the Underwriters’ respective businesses and/or assets.

[The Remainder of This Page Intentionally Left Blank; Signature Page Follows]

If the foregoing correctly sets forth the understanding among the Company and the several Underwriters, please so indicate in the space provided below for that purpose, whereupon this Agreement and the Underwriters’ acceptance shall constitute a binding agreement among the Company and the Underwriters, severally.


Very truly yours, NxStage Medical, Inc.
By:	/s/ Xxxxxx X. Xxxxx
	Name:	Xxxxxx X. Xxxxx
	Title:	Chief Financial Officer and Senior Vice President


Accepted and agreed to as of the date first above written, on behalf of itself Canaccord Genuity Inc.
By:	/s/ Xxxxxxx X. Xxxxxx
	Name:	Xxxxxxx X. Xxxxxx
	Title:	Managing Director

Schedule A

List of Underwriters


Name of Underwriters	Number of Firm Shares

Canaccord Genuity Inc.		3,200,000

Schedule B

Permitted Fee Writing Prospectuses

The NxStage Medical $66 Million Common Stock Offering Terms and Conditions, filed pursuant to Rule 433 of the Act on November 17, 2010.

Schedule C

Disclosure References

None

Exhibit A

NxStage Medical, Inc.

Form of Lock-Up Agreement

November __, 2010

NxStage Medical, Inc.
000 X. Xxxxx Xx., 0^xx Xxxxx
Xxxxxxxx, XX 00000

Canaccord Genuity Inc.
00 Xxxx Xxxxxx, 00^xx Xxxxx
Xxxxxx, Xxxxxxxxxxxxx 00000

Re: NxStage Medical, Inc. — Lock-Up Agreement

Dear Sirs:

In order to induce Canaccord Genuity Inc. (“Canaccord”) to enter into a certain underwriting agreement (the “Underwriting Agreement”) with NxStage Medical, Inc., a Delaware corporation (the “Company”), with respect to the public offering (the “Offering”) of shares of the Company’s Common Stock, par value $0.001 per share (“Common Stock”), the undersigned hereby agrees that during the period from the date hereof until twenty (20) days from the date of the first filing of a final prospectus supplement for the Offering (the “lock-up period”), the undersigned will not, without the prior written consent of Canaccord, directly or indirectly, (i) offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of, or announce the intention to otherwise dispose of, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock (including, without limitation, shares of Common Stock or any such securities which may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations promulgated under the Securities Act of 1933, as the same may be amended or supplemented from time to time (such shares or securities, the “Beneficially Owned Shares”)), (ii) enter into any swap, hedge or other agreement or arrangement that transfers in whole or in part, the economic risk of ownership of any Beneficially Owned Shares, Common Stock or securities convertible into or exercisable or exchangeable for Common Stock, or (iii) engage in any short selling of any Beneficially Owned Shares, Common Stock or securities convertible into or exercisable or exchangeable for Common Stock.

Notwithstanding the foregoing, the undersigned may sell or otherwise transfer shares of Common Stock or Beneficially Owned Shares (i) as a bona fide gift or gifts or pledge, provided that the undersigned provides prior written notice of such gift or gifts or pledge to Canaccord and provided further that the gift(s) or pledge(s) constitute no more than 10% of the Beneficially Owned Shares; any gifts or pledges in excess of that amount shall require the donee or donees or pledgee or pledgees (as the case may be) thereof agree to be bound by the restrictions set forth herein, (ii) either during the undersigned’s lifetime or on death by will or intestacy to the undersigned’s immediate family or to a trust, the beneficiaries of which are exclusively the undersigned and a member or members of the undersigned’s immediate family, provided that the transferee thereof agrees to be bound by the restrictions set forth herein, (iii) pursuant to any 10b5-1 trading plans in effect as of the date of the Offering, (iv) with the prior written consent of Canaccord in its sole discretion, (v) in connection with the exercise of any equity award granted to the undersigned that expires or is otherwise required to be exercised during the lock-up period, or (vi) in connection with an election by the undersigned to have shares withheld or sold to satisfy statutory tax withholding requirements in connection with the vesting of any equity award granted to the undersigned. Notwithstanding the foregoing, and without waiving or releasing any other restrictions on the undersigned pursuant to the Company’s Xxxxxxx Xxxxxxx Policy, the undersigned may establish or modify a 10b5-1 trading plan during the lock up period for the transfer of shares of Common Stock, provided that such plan does not provide for the transfer of Common Stock during the lock-up period. In addition, if the undersigned is a partnership, limited liability company, trust, corporation or similar entity, it may distribute the Common Stock or Beneficially Owned Shares to its partners, members or stockholders; provided, however, that in each such case, prior to any such transfer, each transferee shall execute a duplicate form of this letter agreement or execute an agreement, reasonably satisfactory to Canaccord, pursuant to which each transferee shall agree to receive and hold such Common Stock or Beneficially Owned Shares subject to the provisions hereof, and there shall be no further transfer except in accordance with the provisions hereof. For the purposes of this paragraph, “immediate family” shall mean spouse, domestic partner, lineal descendant (including adopted children), father, mother, brother or sister of the transferor, as well as any non-profit organization or charitable organization.

The undersigned understands that the undersigned shall be released from all obligations under this Agreement if (i) the Company notifies Canaccord that it does not intend to proceed with the Offering, (ii) the Underwriting Agreement does not become effective, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Common Stock to be sold thereunder, or (iii) the Offering is not completed by December 15, 2010.

In addition, the undersigned hereby waives, from the date hereof until the expiration of the lock-up period, any and all rights, if any, to request or demand registration pursuant to the Securities Act of 1933, as amended, of any shares of Common Stock or securities convertible into or exercisable or exchangeable for Common Stock that are registered in the name of the undersigned or that are Beneficially Owned Shares. In order to enable the aforesaid covenants to be enforced, the undersigned hereby consents to the placing of legends and/or stop-transfer orders with the transfer agent of the Common Stock with respect to any shares of Common Stock, securities convertible into or exercisable or exchangeable for Common Stock or Beneficially Owned Shares owned by the undersigned.

[Remainder of page intentionally blank]

The undersigned understands that the Company and Canaccord are relying upon this Lock-Up Agreement in proceeding toward consummation of the offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors and assigns.


				Very truly yours,

Date:

				Signature


				Print Name


				Title

Exhibit B

Xxxxx Lovells US LLP Opinion and Negative Assurance Letter

Opinion:

(a) The Company is validly existing as a corporation and in good standing as of the date of the Good Standing Certificate under the laws of the State of Delaware. The Company has the corporate power to own, lease and operate its current properties and to conduct its business as described in the Prospectus and to execute and deliver, and to perform its obligations under, the Underwriting Agreement.

(b) Based solely on a review of the Subsidiary Good Standing Certificate, the Significant Subsidiary is in good standing as of the date of the Subsidiary Good Standing Certificate under the laws of the State of Washington.

(c) The authorized capital stock of the Company is as set forth under the caption “Capitalization” in the Prospectus. No holder of outstanding shares of common stock of the Company has any preemptive right under the Corporation Act, the Certificate of Incorporation or Bylaws or, to our knowledge, any contractual right to subscribe for any of the Shares.

(d) The Agreement has been duly authorized, executed and delivered by the Company.

(e) The Shares have been duly authorized and, when issued in accordance with the provisions of the Agreement, will be validly issued, fully paid and non-assessable.

(f) Based solely upon telephone communications between an attorney of this firm and a member of the staff of the Commission, the Registration Statement has become effective under the Securities Act, and to our knowledge, no stop order suspending the effectiveness of the Registration Statement or suspending or preventing the use of the Prospectus has been issued and no proceedings for that purpose have been instituted or are threatened by the Commission. The required filings of the Prospectus pursuant to Rule 424(b) promulgated pursuant to the Securities Act have been made in the manner and within the time period required by Rule 424(b).

(g) The Registration Statement and the Prospectus (except for the financial statements and supporting schedules included therein, as to which we express no opinion) comply as to form in all material respects with the requirements of the Securities Act and the applicable rules and regulations thereunder.

(h) The information in the Prospectus under the captions “Description of Our Common Stock” and “Material U.S. Federal Tax Considerations for Non-U.S. Holders” to the extent that such information constitutes summaries of laws, rules or regulations, and insofar as the information in the Prospectus under the caption “Description of Our Common Stock” describe the terms of the Company’s Certificate of Incorporation or Bylaws, is accurate in all material respects. The Common Stock conforms as to legal matters in all material respects to the description thereof set forth in the Prospectus under the caption “Description of Our Common Stock”.

(i) The execution, delivery and performance on the date hereof by the Company of the Agreement do not (i) violate the Corporation Act or the Certificate of Incorporation or Bylaws of the Company, (ii) violate any provision of Applicable Federal Law or any provision of Applicable State Law or (iii) breach or constitute a default under any of the Company Contracts (except that we express no opinion with respect to any matters that would require a mathematical calculation or a financial or accounting determination).

(j) No approval or consent of, or registration or filing with, any federal governmental agency or any Delaware governmental agency is required to be obtained or made by the Company under Applicable Federal Law or Applicable State Law or under the Corporation Act in connection with the execution, delivery and performance on the date hereof by the Company of the Agreement.

(k) The Company is not, and after giving effect to the issuance of the Shares and the application of the proceeds as described in the Prospectus, will not be, an “investment company” within the meaning of the Investment Company Act of 1940, as amended.

Negative Assurance:

Subject to the foregoing, we confirm to you that, on the basis of the information we gained in the course of performing the services referred to above, no facts have come to our attention that cause us to believe that:

(i) the Registration Statement, at the time it became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading;

(ii) the Prospectus, as of its date, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; or

(iii) the Pricing Disclosure Package, as of 4:15 P.M. (Boston time) on November 17, 2010 (which you have informed us is a time prior to the time of the first sale of the Shares by the Underwriter), contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

provided that in making the foregoing statements, we do not express any belief with respect to the financial statements and supporting schedules and other financial or accounting information and data derived from such financial statements and schedules or the books and records of the Company or assessments of or reports on the effectiveness of internal control over financial reporting contained or incorporated by reference in or omitted from the Registration Statement, the Pricing Disclosure Package, or the Prospectus.

Exhibit C

Miles and Stockbridge Opinion

1. To the best of our knowledge, the inventors have executed conventional assignment forms designating the Company as Assignee, and these assignments have been properly recorded in the US Patent Office.

2. To the best of our knowledge, assignments in conventional form have been obtained from the inventors assigning all rights in the Patents to the Company for all of the Patents filed in the US Patent Office (except those marked with an asterisk) and properly recorded in the US Patent Office.

3. To the best of our knowledge, each of the pending US patent applications included in the Patents is currently active and has not been abandoned by the Company.

4. To the best of our knowledge, we have complied fully with the duty to disclose material information to the US Patent Office as defined in 37 CFR 1.56, have advanced good faith arguments in prosecuting the Patents and, where required by a foreign patent authority, we have provided prior art according to the requests made by foreign agents engaged to handle the foreign Patents.

5. To the best of our knowledge, the issued Patents have been duly maintained and we are not aware that any of them has been adjudged invalid or unenforceable in whole or in part.

6. To the best of our knowledge, there is no pending or threatened action, suit, proceeding or claim by any third party that any of the Patents infringes, misappropriates or otherwise violates any intellectual property or other proprietary rights of any third party.

Document Metadata

Table of Contents

NxStage Medical, Inc. 3,200,000 Shares Common Stock ($0.001 par value) Underwriting Agreement

Document Metadata