Omeros 8K Prices $35.0 Million Public Offering of Common Stock | OMER 18 Mar 14

Exhibit 1.1

EXECUTION COPY

3,043,479

OMEROS CORPORATION

Common Stock

UNDERWRITING AGREEMENT

March 14, 2014

COWENAND COMPANY, LLC

As Representative of the several Underwriters

c/o Cowen and Company, LLC

599 Lexington Avenue

New York, New York 10022

Dear Sirs:

1.INTRODUCTORY. Omeros Corporation, a Washington corporation (the “Company”), proposes to sell, pursuant to the terms of this Agreement, to the several underwriters named inSchedule A hereto (the “Underwriters,” or, each, an “Underwriter”), an aggregate of 3,043,479 shares of common stock, $0.01 par value (the “Common Stock”) of the Company. The aggregate of 3,043,479 shares so proposed to be sold is hereinafter referred to as the “Firm Stock.” The Company also proposes to sell to the Underwriters, upon the terms and conditions set forth in Section 3 hereof, up to an additional 456,521 shares of Common Stock (the “Optional Stock”). The Firm Stock and the Optional Stock are hereinafter collectively referred to as the “Stock.” Cowen and Company, LLC is acting as representative of the several Underwriters and in such capacity is hereinafter referred to as the “Representative.”

2.REPRESENTATIONSAND WARRANTIESOFTHE COMPANY. The Company represents and warrants to the several Underwriters, as of the date hereof and as of each Closing Date (as defined below), and agrees with the several Underwriters, that:

(a) A registration statement of the Company on FormS-3 (FileNo. 333-169856) (including all pre-effective amendments thereto and all post-effective amendments thereto filed before execution of this Agreement, the “Initial Registration Statement”) in respect of the Stock has been filed with the Securities and Exchange Commission (the “Commission”) pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”). The Company meets the requirements for use of FormS-3 under the Securities Act, and the rules and regulations of the Commission thereunder (the “Rules and Regulations”). The Initial Registration Statement and any post-effective amendment thereto, each in the form heretofore delivered to you, and, excluding exhibits thereto, for each of the other Underwriters, have been declared effective by the Commission in such form and meet the requirements of the Securities Act, and the Rules and Regulations in all material respects. The aggregate market value of the Company’s voting and non-voting common equity held by non-affiliates of the Company was at least $75 million within 60 days prior to the date of filing the Company’s most recent Annual Report on Form 10-K. Other than (i) the Initial Registration Statement, (ii) a registration statement, if any, increasing the size of the offering filed pursuant to Rule 462(b) of the Rules and Regulations (a “Rule 462(b) Registration Statement”), (iii) the Prospectus (as defined below) contemplated by this Agreement to be filed pursuant to Rule 424(b) of the Rules and Regulations in accordance with Section 4(a) hereof and (iv) any Issuer Free Writing Prospectus (as defined below), no other document with respect to the offer and sale of the Stock has heretofore been filed with the Commission. No stop order suspending the effectiveness of the Initial Registration Statement, any post-effective amendment thereto or the Rule 462(b) Registration Statement, if any, has been issued and no proceeding for that purpose or pursuant to Section 8A of the Securities Act has been initiated or threatened by the Commission (the Base Prospectus (as defined below), as supplemented by a preliminary prospectus relating to the offer and sale of the Stock, is hereinafter called a “Preliminary Prospectus”). The various parts of the Initial Registration Statement and the Rule 462(b) Registration Statement, if any, in each case including all exhibits thereto and including (i) the information contained in the Prospectus filed with the

Commission pursuant to Rule 424(b) of the Rules and Regulations and deemed by virtue of Rule 430A, 430B or 430C of the Rules and Regulations to be part of the Initial Registration Statement at the time specified in the applicable Rule and (ii) the documents incorporated by reference in the Rule 462(b) Registration Statement at the time the Rule 462(b) Registration Statement became effective, are hereinafter collectively called the “Registration Statements.” The base prospectus included in the Initial Registration Statement at the time of effectiveness thereof (the “Base Prospectus”), as supplemented by the final prospectus supplement relating to the offer and sale of the Stock, in the form filed pursuant to and within the time limits described in Rule 424(b) of the Rules and Regulations, is hereinafter called the “Prospectus.”

Any reference herein to any Registration Statement, Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein, to the extent such information has not been superseded or modified in accordance with Rule 412 of the Rules and Regulations. Any reference to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents filed after the date of such Preliminary Prospectus or the Prospectus under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and deemed incorporated by reference in such Preliminary Prospectus or Prospectus, as the case may be. Any reference to (i) any Registration Statement shall be deemed to refer to and include any document filed under the Exchange Act that is deemed incorporated by reference in such Registration Statement, including the annual report of the last completed fiscal year of the Company on Form 10-K filed under Section 13(a) or 15(d) of the Exchange Act on or prior to the date hereof and (ii) the effective date of such Registration Statement shall be deemed to refer to and include the date such Registration Statement became effective and, if later, the date such Form 10-K was so filed. Any reference to any amendment to the Registration Statements shall be deemed to refer to and include any document filed under the Exchange Act that is deemed incorporated by reference in such Registration Statement, including any annual report of the Company filed pursuant to Section 13(a) or 15(d) of the Exchange Act after the date of this Agreement that is incorporated by reference in the Registration Statement.

(b) As of the Applicable Time (as defined below) and as of the Closing Date or the Option Closing Date (as defined below), as the case may be, neither (i) the General Use Free Writing Prospectus(es) (as defined below) issued at or prior to the Applicable Time, the Pricing Prospectus (as defined below) and the information included onSchedule B hereto, all considered together (collectively, the “General Disclosure Package”), (ii) any individual Limited Use Free Writing Prospectus (as defined below), nor (iii) any “bona fide electronic road show” (as defined in Rule 433(h)(5) of the Rules and Regulations), when considered together with the General Disclosure Package, included or will include any untrue statement of a material fact or omitted or will 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 representations or warranties as to information contained in or omitted from the Pricing Prospectus, in reliance upon, and in conformity with, written information furnished to the Company through any Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriter’s Information as defined in Section 17. As used in this paragraph (b) and elsewhere in this Agreement:

“Applicable Time” means 8:30 A.M., New York time, on the date of this Agreement or such other time as agreed to by the Company and the Representative.

“Pricing Prospectus” means the Preliminary Prospectus, as amended and supplemented, relating to the Stock that is included in the Registration Statement immediately prior to the Applicable Time, including any document incorporated by reference therein and any prospectus supplement deemed to be a part thereof.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the Rules and Regulations relating to the Stock in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g) of the Rules and Regulations.

“General Use Free Writing Prospectus” means any Issuer Free Writing Prospectus that is identified onSchedule C to this Agreement.

“Limited Use Free Writing Prospectuses” means any Issuer Free Writing Prospectus that is not a General Use Free Writing Prospectus.

(c) No order preventing or suspending the use of any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus relating to the proposed offering of the Stock has been issued by the Commission, and no proceeding for that purpose or pursuant to Section 8A of the Securities Act has been instituted or, to the Company’s knowledge, threatened by the Commission, and each Preliminary Prospectus, at the time of filing thereof, conformed in all material respects to the requirements of the Securities Act and the Rules and Regulations, and did 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, in the light of the circumstances under which they were made, not misleading;provided, however, that the Company makes no representations or warranties as to information contained in or omitted from any Preliminary Prospectus, an Issuer Free Writing Prospectus or a Prospectus, in reliance upon, and in conformity with, written information furnished to the Company through the Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriter’s Information as defined in Section 17.

(d) At the respective times the Registration Statements and any amendments thereto became or become effective, at the date of this Agreement and at each Closing Date, each Registration Statement and any amendments thereto conformed and will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations and did not and will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading; and the Prospectus and any amendments or supplements thereto, at the time the Prospectus or any amendment or supplement thereto was filed with the Commission and at each Closing Date, conformed and will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations and did not and will not contain an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading; provided,however, that the foregoing representations and warranties in this paragraph (d) shall not apply to information contained in or omitted from the Registration Statements or the Prospectus, or any amendment or supplement thereto, in reliance upon, and in conformity with, written information furnished to the Company through any Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriter’s Information (as defined in Section 17).

(e) Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Stock or until any earlier date that the Company notified or notifies the Representative as described in Section 4(f), did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, Pricing Prospectus or the Prospectus, including any document incorporated by reference therein and any prospectus supplement deemed to be a part thereof, or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(f) The documents incorporated by reference in the Prospectus, when they were filed with the Commission, conformed in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder and none of such documents when filed contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Prospectus, when such documents are filed with Commission will conform in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder and will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading.

(g) The Company has not, directly or indirectly, distributed and will not distribute any offering material in connection with the offering and sale of the Stock other than any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus and other materials, if any, permitted under the Securities Act and consistent with Section 4(b) below. The Company will file with the Commission all Issuer Free Writing Prospectuses (other than a “bona fide electronic road show” as defined in Rule 433(h)(5) of the Rules and Regulations) in the time and manner required under Rules 163(b)(2) and 433(d) of the Rules and Regulations.

(h) (A) At the time of filing the Initial Registration Statement, any 462(b) Registration Statement and any post-effective amendments thereto, and at the date hereof, the Company was not, and the Company currently is not, an “ineligible issuer,” as defined in Rule 405 of the Rules and Regulations.

(i) The Company and each of its Subsidiaries (as defined in Section 15) have been duly organized and are validly existing as corporations or other legal entities in good standing (or the foreign equivalent thereof) under the laws of their respective jurisdictions of organization. The Company and each of its Subsidiaries are duly qualified to do business and are in good standing as foreign corporations or other legal entities in each jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such qualification and have all power and authority (corporate or other) necessary to own or hold their respective properties and to conduct the businesses in which they are engaged, except where the failure to so qualify or have such power or authority would not (i) have, singularly or in the aggregate, a material adverse effect on the condition (financial or otherwise), results of operations, assets, business or prospects of the Company and its Subsidiaries taken as a whole, or (ii) impair in any material respect the ability of the Company to perform its obligations under this Agreement or to consummate any transactions contemplated by this Agreement, the General Disclosure Package or the Prospectus (any such effect as described in clauses (i) or (ii), a “Material Adverse Effect”). The Company owns or controls, directly or indirectly, only the following corporations, partnerships, limited liability partnerships, limited liability companies, associations or other entities: nura, inc. and the Foreign Subsidiaries (as hereinafter defined).

(j) This Agreement has been duly authorized, executed and delivered by the Company.

(k) The Stock to be issued and sold by the Company to the Underwriters hereunder has been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued, fully paid and nonassessable and free of any preemptive or similar rights and will conform to the description thereof contained in the General Disclosure Package and the Prospectus.

(l) The Company has an authorized capitalization as set forth under the heading “Capitalization” in the Pricing Prospectus, and all of the issued shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and non-assessable, have been issued in compliance with federal and state securities laws, and conform to the description thereof contained in the General Disclosure Package and the Prospectus. As of March 12, 2014, there were 30,397,366 shares of Common Stock issued and outstanding and no shares of preferred stock, par value $0.01 of the Company, issued and outstanding and 7,514,096 shares of Common Stock were issuable upon the exercise of all options, warrants and convertible securities outstanding as of such date. Since such date, the Company has not issued any securities (other than options to purchase common stock pursuant to the Company’s stock option plan or securities issued upon the exercise of stock options or warrants in the ordinary course of business). All of the Company’s options, warrants and other rights to purchase or exchange any securities for shares of the Company’s capital stock have been duly authorized and validly issued and were issued in compliance with federal and state securities laws. None of the outstanding shares of Common Stock was issued in violation of any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. There are no authorized or outstanding shares of capital stock, options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or debt securities convertible into or exchangeable or exercisable for, any capital stock of the Company or any of its Subsidiaries other than those described above or accurately described in the General Disclosure Package. The description of the

Company’s stock option plans and the options or other rights granted thereunder, as described in the General Disclosure Package and the Prospectus, accurately and fairly present the information required to be shown with respect to such plans, arrangements, options and rights.

(m) All the outstanding shares of capital stock (if any) of each Subsidiary of the Company have been duly authorized and validly issued, are fully paid and nonassessable and, except to the extent set forth in the General Disclosure Package or the Prospectus, are owned by the Company directly or indirectly through one or more wholly owned Subsidiaries, free and clear of any claim, lien, encumbrance, security interest, restriction upon voting or transfer or any other claim of any third party.

(n) The execution, delivery and performance of this Agreement by the Company, the issue and sale of the Stock by the Company and the consummation of the transactions contemplated hereby will not (with or without notice or lapse of time or both) (i) conflict with or result in a breach or violation of any of the terms or provisions of, constitute a default or a Debt Repayment Triggering Event (as defined below) under, give rise to any right of termination or other right or the cancellation or acceleration of any right or obligation or loss of a benefit under, or give rise to the creation or imposition of any lien, encumbrance, security interest, claim or charge upon any property or assets of the Company or any Subsidiary pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its Subsidiaries is a party or by which the Company or any of its Subsidiaries is bound or to which any of the property or assets of the Company or any of its Subsidiaries is subject, (ii) result in any violation of the provisions of the charter or by-laws (or analogous governing instruments, as applicable) of the Company or any of its Subsidiaries or (iii) result in a violation of any law, statute, rule, regulation, judgment, order or decree of any court or governmental agency or body, domestic or foreign, having jurisdiction over the Company or any of its Subsidiaries or any of their properties or assets. A “Debt Repayment Triggering Event” means any event or condition that gives, or with the giving of notice or lapse of time would give the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company of any of its Subsidiaries.

(o) Except for the registration of the Stock under the Securities Act and applicable state or foreign securities laws and the listing of the Stock on the Nasdaq Global Market (the “Exchange”), no consent, approval, authorization or order of, or filing, qualification or registration (each an “Authorization”) with, any court, governmental or non-governmental agency or body, foreign or domestic, which has not been made, obtained or taken and is not in full force and effect, is required for the execution, delivery and performance of this Agreement by the Company, the offer or sale of the Stock or the consummation of the transactions contemplated hereby; and no event has occurred that allows or results in, or after notice or lapse of time or both would allow or result in, revocation, suspension, termination or invalidation of any such Authorization or any other impairment of the rights of the holder or maker of any such Authorization. All corporate approvals (including those of shareholders) necessary for the Company to consummate the transactions contemplated by this Agreement have been obtained and are in effect.

(p) Ernst & Young LLP, which has certified certain financial statements included or incorporated by reference in the Registration Statements, the General Disclosure Package and the Prospectus, and has audited the Company’s internal control over financial reporting and management’s assessment thereof, is an independent registered public accounting firm within the meaning of Article 2-01 of Regulation S-X and the Public Company Accounting Oversight Board (the “PCAOB”).

(q) The financial statements, together with the related notes, included or incorporated by reference in the General Disclosure Package, the Prospectus and in each Registration Statement fairly present in all material respects the financial position and the results of operations and changes in financial position of the Company and its consolidated Subsidiaries at the respective dates or for the respective periods therein specified. Such statements and related notes have been prepared in accordance with the generally accepted accounting principles in the United States (“GAAP”) applied on a consistent basis throughout the periods involved except as may be set forth in the related notes included or incorporated by reference in the General Disclosure Package. The financial statements, together with the related notes, included or incorporated by reference in the General Disclosure Package and the Prospectus comply in all material respects with Regulation S-X. No other financial statements or supporting schedules or exhibits are

required by Regulation S-X to be described, included or incorporated by reference in the Registration Statements, the General Disclosure Package or the Prospectus. The summary and selected financial data included or incorporated by reference in the General Disclosure Package, the Prospectus and each Registration Statement fairly present in all material respects the information shown therein as at the respective dates and for the respective periods specified and are derived from the consolidated financial statements set forth or incorporated by reference in the Registration Statement, the Pricing Prospectus and the Prospectus and other financial information. All information contained in the Registration Statement, the General Disclosure Package and the Prospectus regarding “non-GAAP financial measures” (as defined in Regulation G) complies with Regulation G and Item 10 of Regulation S-K, to the extent applicable.

(r) The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the each Registration Statement fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto.

(s) Neither the Company nor any of its Subsidiaries has sustained, since the date of the latest audited financial statements included or incorporated by reference in the General Disclosure Package, any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the General Disclosure Package; and, since such date, there has not been any material change in the capital stock or long-term debt of the Company or any of its Subsidiaries (other than stock option and warrant exercises and stock repurchases in the ordinary course of business or the repayment of long-term debt as described in the General Disclosure Package), or any material adverse changes, or any development that reasonably would have a Material Adverse Effect, in or affecting the business, assets, general affairs, management, financial position, prospects, shareholders’ equity or results of operations of the Company and its Subsidiaries taken as a whole, otherwise than as set forth or contemplated in the General Disclosure Package.

(t) Except as set forth in the General Disclosure Package, there is no legal or governmental 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, including any proceeding before the United States Food and Drug Administration of the U.S. Department of Health and Human Services (“FDA”) or comparable federal, state, local or foreign governmental bodies (it being understood that the interaction between the Company and the FDA and such comparable governmental bodies relating to the clinical development and product approval process shall not be deemed proceedings for purposes of this representation), which is required to be described in the Registration Statement, the General Disclosure Package or the Prospectus or a document incorporated by reference therein and is not described therein, or which, singularly or in the aggregate, if determined adversely to the Company or any of its Subsidiaries, could reasonably be expected to have a Material Adverse Effect; and except as set forth in the General Disclosure Package, to the best of the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities. The Company is in compliance with all applicable federal, state, local and foreign laws, regulations, orders and decrees governing its business as prescribed by the FDA, or any other federal, state or foreign agencies or bodies engaged in the regulation of pharmaceuticals or biohazardous substances or materials, except where noncompliance would not, singly or in the aggregate, have a Material Adverse Effect. All preclinical and clinical studies conducted by or on behalf of the Company that the Company reasonably expects will be used to support approval for commercialization of the Company’s products have been conducted by the Company, or to the Company’s knowledge by third parties, in compliance with all applicable federal, state or foreign laws, rules, orders and regulations, except for such failure or failures to be in compliance as could not reasonably be expected to have, singly or in the aggregate, a Material Adverse Effect.

(u) Neither the Company nor any of its Subsidiaries (i) is in violation of its respective charter or by-laws (or analogous governing instrument, as applicable), (ii) is in default in any respect, and no event has occurred which, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which it is a party or by which it is bound or to which any of its property or assets is subject or (iii) is in violation in any respect of any law,

ordinance, governmental rule, regulation or court order, decree or judgment to which it or its property or assets may be subject (including, without limitation, those administered by the FDA or by any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) except, in the case of clauses (ii) and (iii) of this paragraph (u), as disclosed in the General Disclosure Package and the Prospectus and for any violations or defaults which, singularly or in the aggregate, would not have a Material Adverse Effect.

(v) The Company and each of its Subsidiaries possess all licenses, certificates, authorizations and permits issued by, and have made all declarations and filings with, the appropriate local, state, federal or foreign regulatory agencies or bodies (including, without limitation, those administered by the FDA or by any foreign, federal, state or local governmental or regulatory authority performing functions similar to those performed by the FDA) which are necessary for the ownership of their respective properties or the conduct of their respective businesses as currently conducted and as described in the General Disclosure Package and the Prospectus (collectively, the “Governmental Permits”) except (a) where any failures to possess or make the same, singularly or in the aggregate, would not have a Material Adverse Effect and (b) as disclosed in the General Disclosure Package, Registration Statement and Prospectus. The Company and its Subsidiaries are in compliance with all such Governmental Permits; all such Governmental Permits are valid and in full force and effect, except where the validity or failure to be in full force and effect would not, singularly or in the aggregate, have a Material Adverse Effect. All such Governmental Permits are free and clear of any restriction or condition that are in addition to, or materially different from those normally applicable to similar licenses, certificates, authorizations and permits. Neither the Company nor any Subsidiary has received notification of any revocation, modification, suspension, termination or invalidation (or proceedings related thereto) of any such Governmental Permit and to the knowledge of the Company, no event has occurred that allows or results in, or after notice or lapse of time or both would allow or result in, revocation, modification, suspension, termination or invalidation (or proceedings related thereto ) of any such Governmental Permit and the Company has no reason to believe that any such Governmental Permit will not be renewed. The studies, tests and preclinical or clinical trials conducted by or on behalf of the Company that are described in the General Disclosure Package and the Prospectus (the “Company Studies and Trials”) were and, if still pending, are being, conducted in all material respects in accordance with experimental protocols, procedures and controls pursuant to, where applicable, accepted professional scientific standards, except where noncompliance with such protocols, procedures and controls would not, singularly or in the aggregate, have a Material Adverse Effect; the descriptions of the results of the Company Studies and Trials contained in the General Disclosure Package and Prospectus are accurate in all material respects; and except as set forth in the General Disclosure Package and the Prospectus, the Company has not received any notices or correspondence with the FDA or any foreign, state or local governmental body exercising comparable authority requiring the termination, suspension or material modification of any Company Studies or Trials that termination, suspension or material modification would reasonably be expected to have a Material Adverse Effect.

(w) Neither the Company nor any of its Subsidiaries is or, after giving effect to the offering of the Stock and the application of the proceeds thereof as described in the General Disclosure Package and the Prospectus, will become required to register as an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(x) Neither the Company nor any of its officers, directors or affiliates has taken or will take, directly or indirectly, any action designed or intended to stabilize or manipulate the price of any security of the Company, or which caused or resulted in, or which might in the future reasonably be expected to cause or result in, stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Stock in violation of the Exchange Act.

(y) The Company and its Subsidiaries own or possess the valid right to use all (i) valid and enforceable patents, patent applications, trademarks, trademark registrations, service marks, service mark registrations, Internet domain name registrations, copyrights, copyright registrations, licenses, trade secret rights necessary to conduct their respective businesses as currently conducted, and as currently proposed to be conducted and described in the General Disclosure Package and the Prospectus (“Intellectual Property Rights”) and (ii) inventions, software, works of authorships, trade marks, service marks, trade names,

databases, formulae, know how, Internet domain names and other intellectual property (including trade secrets and other unpatented and/or unpatentable proprietary confidential information, systems, or procedures) necessary to conduct their respective businesses as currently conducted, and as currently proposed to be conducted and described in the General Disclosure Package and the Prospectus (collectively, “Intellectual Property Assets”). The Company and its Subsidiaries have not received written notice of any challenge by any person to the rights of the Company and its Subsidiaries with respect to any Intellectual Property Rights or Intellectual Property Assets owned or used by the Company or its Subsidiaries. To the knowledge of the Company, the Company and its Subsidiaries’ respective businesses as now conducted and as currently proposed to be conducted and described in the General Disclosure Package and the Prospectus do not give rise to any infringement of, any misappropriation of, or other violation of, any valid and enforceable Intellectual Property Rights of any other person that could reasonably be expected to have a Material Adverse Effect. All licenses for the use of the Intellectual Property Rights described in the General Disclosure Package and the Prospectus are valid, binding upon, and enforceable by or against the parties thereto in accordance to its terms. The Company has complied in all material respects with, and is not in breach nor has received any asserted or threatened claim of breach of any Intellectual Property license, and the Company has no knowledge of any breach by any other person to any Intellectual Property license that could reasonably be expected to have a Material Adverse Effect. No claim has been made against the Company alleging the infringement by the Company of any patent, trademark, service mark, trade name, copyright, trade secret, license in or other intellectual property right or franchise right of any person nor to the Company’s knowledge is there any reasonable basis for such a claim that could reasonably be expected to have a Material Adverse Effect. The Company has taken reasonable steps to protect, maintain and safeguard its Intellectual Property Rights, including the execution of appropriate nondisclosure and confidentiality agreements, proprietary information and invention agreements, consulting agreements and services agreements by relevant contractors, consultants and employees. The consummation of the transactions contemplated by this Agreement will not result in the loss or impairment of or payment of any additional amounts with respect to, nor require the consent of any other person in respect of, the Company’s right to own, use, or hold for use any of the Intellectual Property Rights as owned, used or held for use in the conduct of the business as currently conducted. The Company has at all times complied in all material respects with all applicable laws relating to privacy, data protection, and the collection and use of personal information collected, used, or held for use by the Company in the conduct of the Company’s business. No claims have been asserted or, to the knowledge of the Company, threatened against the Company alleging a violation of any person’s privacy or personal information or data rights and the consummation of the transactions contemplated hereby will not breach or otherwise cause any violation of any law related to privacy, data protection, or the collection and use of personal information collected, used, or held for use by the Company in the conduct of the Company’s business. The Company takes reasonable measures to ensure that such information is protected against unauthorized access, use, or modification. The Company has taken all necessary actions to obtain ownership of all works of authorship and inventions made by its employees, consultants and contractors during the time they were employed by or under contract with the Company and which relate to the Company’s business. All scientific founders and key employees have signed confidentiality, invention assignment or proprietary information and invention agreements with the Company.

(z) The Company and each of its Subsidiaries have valid title to, or have valid rights to lease or otherwise use, all items of real or personal property which are material to the business of the Company and its Subsidiaries taken as a whole, in each case and except as described in the Registration Statement, Disclosure Package and Prospectus, free and clear of all liens, encumbrances, security interests, claims and defects that do not, singularly or in the aggregate, materially affect the value of such property and do not interfere with the use made and proposed to be made of such property by the Company or any of its Subsidiaries; and all of the leases and subleases material to the business of the Company and its Subsidiaries, considered as one enterprise, and under which the Company or any of its Subsidiaries holds properties described in the General Disclosure Package and the Prospectus, are in full force and effect, and neither the Company nor any Subsidiary has any notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company or any Subsidiary under any of the leases or subleases mentioned above, or affecting or questioning the rights of the Company or such Subsidiary to the continued possession of the leased or subleased premises under any such lease or sublease.

(aa) There is (A) no material unfair labor practice complaint pending against the Company, or any of its Subsidiaries, nor to the knowledge of the Company, threatened against it or any of its Subsidiaries, before the National Labor Relations Board, any state or local labor relation board or any foreign labor relations board, and no material grievance or significant arbitration proceeding arising out of or under any collective bargaining agreement is so pending against the Company or any of its Subsidiaries, or, to the knowledge of the Company, threatened against it and (B) no labor disturbance by the employees of the Company or any of its Subsidiaries exists or, to the Company’s knowledge, is imminent, and the Company is not aware of any existing or imminent labor disturbance by the employees of any of its or its Subsidiaries principal suppliers, manufacturers, customers or contractors, that could reasonably be expected, singularly or in the aggregate, to have a Material Adverse Effect. The Company is not aware that any key employee or significant group of employees of the Company or any Subsidiary plans to terminate employment with the Company or any such Subsidiary.

(bb) No “prohibited transaction” (as defined in Section 406 of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder (“ERISA”), or Section 4975 of the Internal Revenue Code of 1986, as amended from time to time (the “Code”)) or “accumulated funding deficiency” (as defined in Section 302 of ERISA) or any of the events set forth in Section 4043(b) of ERISA (other than events with respect to which the thirty (30)-day notice requirement under Section 4043 of ERISA has been waived) has occurred or could reasonably be expected to occur with respect to any employee benefit plan of the Company or any of its Subsidiaries which could, singularly or in the aggregate, have a Material Adverse Effect. Each employee benefit plan of the Company or any of its Subsidiaries is in compliance in all material respects with applicable law, including ERISA and the Code. The Company and its Subsidiaries have not incurred and could not reasonably be expected to incur liability under Title IV of ERISA with respect to the termination of, or withdrawal from, any pension plan (as defined in ERISA). Each pension plan for which the Company or any of its Subsidiaries would have any liability that is intended to be qualified under Section 401(a) of the Code is so qualified, and nothing has occurred, whether by action or by failure to act, which could, singularly or in the aggregate, cause the loss of such qualification.

(cc) The Company and its Subsidiaries are in compliance with all foreign, federal, state and local rules, laws and regulations relating to the use, treatment, storage and disposal of hazardous or toxic substances or waste and protection of health and safety or the environment which are applicable to their businesses (“Environmental Laws”) except where such noncompliance with Environmental Laws would not, individually or in the aggregate, have a Material Adverse Effect. There has been no storage, generation, transportation, handling, treatment, disposal, discharge, emission, or other release of any kind of toxic or other wastes or other hazardous substances by, due to, or caused by the Company or any of its Subsidiaries (or, to the Company’s knowledge, any other entity for whose acts or omissions the Company or any of its Subsidiaries is or may otherwise be liable) upon any of the property now or previously owned or leased by the Company or any of its Subsidiaries, or upon any other property, in violation of any law, statute, ordinance, rule, regulation, order, judgment, decree or permit or which would, under any law, statute, ordinance, rule (including rule of common law), regulation, order, judgment, decree or permit, give rise to any material liability; and there has been no disposal, discharge, emission or other release of any kind onto such property or into the environment surrounding such property of any toxic or other wastes or other hazardous substances with respect to which the Company or any of its Subsidiaries has knowledge. In the ordinary course of business, the Company and its Subsidiaries conduct periodic reviews of the effect of Environmental Laws on their business and assets, in the course of which they identify and evaluate associated costs and liabilities (including, without limitation, any material capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or Governmental Permits issued thereunder, any related material constraints on operating activities and any potential material liabilities to third parties). On the basis of such reviews, the Company has reasonably concluded that such associated costs and liabilities would not have, singularly or in the aggregate, a Material Adverse Effect.

(dd) The Company and its Subsidiaries each (i) have timely filed all federal, state, local and foreign tax returns (or timely filed applicable extensions therefor) that have been required to be filed, and all such returns were true, complete and correct, (ii) have paid all federal, state, local and foreign taxes, assessments, governmental or other charges due and payable for which it is liable, including, without limitation, all sales and use taxes and all taxes which the Company or any of its Subsidiaries is obligated to

withhold from amounts owing to employees, creditors and third parties, and (iii) do not have any tax deficiency or claims outstanding or assessed or, to its knowledge, proposed against any of them, except those, in each of the cases described in clauses (i), (ii) and (iii) of this paragraph (dd), that would not, singularly or in the aggregate, have a Material Adverse Effect. The Company and its Subsidiaries have not engaged in any transaction which is a corporate tax shelter or which could be characterized as such by the Internal Revenue Service or any other taxing authority. The accruals and reserves on the books and records of the Company and its Subsidiaries in respect of tax liabilities for any taxable period not yet finally determined are adequate to meet any assessments and related liabilities for any such period, and since December 31, 2013 the Company and its Subsidiaries have not incurred any liability for taxes other than in the ordinary course.

(ee) The Company and each of its Subsidiaries carry, or are covered by, insurance in such amounts and covering such risks as is adequate for the conduct of their respective businesses and the value of their respective properties and as is customary for companies engaged in similar businesses in similar industries. Neither the Company nor any of its Subsidiaries has any 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 from similar insurers as may be necessary to continue its business at a cost that would not have a Material Adverse Effect. All policies of insurance owned by the Company or any of its Subsidiaries are, to the Company’s knowledge, in full force and effect and the Company and its Subsidiaries are in compliance with the terms of such policies. Neither the Company nor any of its Subsidiaries has received written notice from any insurer, agent of such insurer or the broker of the Company or any of its Subsidiaries that any material capital improvements or any other material expenditures (other than premium payments) are required or necessary to be made in order to continue such insurance. None of the Company or any of its Subsidiaries insures risk of loss through any captive insurance, risk retention group, reciprocal group or by means of any fund or pool of assets specifically set aside for contingent liabilities other than as described in the General Disclosure Package.

(ff) The Company maintains a system of internal control over financial reporting (as such term is defined in Rule 13a-15(f) of the General Rules and Regulations under the Exchange Act (the “Exchange Act Rules”)) that complies with the requirements of the Exchange Act and has been designed by the Company’s principal executive officer and principal financial officer, or under their supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP. The Company’s internal control over financial reporting, as evaluated pursuant to Rule 13a-15 under the Exchange Act Rules, is effective. Except as described in the General Disclosure Package, since the end of the Company’s most recent audited fiscal year, there has been (A) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (B) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting. The Company’s internal control over financial reporting is overseen by the Audit Committee of the Board of Directors of the Company (the “Audit Committee”) in accordance with the Exchange Act Rules. The Company has not publicly disclosed or reported to the Audit Committee or to the Board, and within the next 90 days the Company does not reasonably expect to publicly disclose or report to the Audit Committee or the Board, a significant deficiency, material weakness, change in internal control over financial reporting or fraud involving management or other employees who have a significant role in the internal control over financial reporting (each an “Internal Control Event”), any violation of, or failure to comply with, the federal securities laws, or any matter which if determined adversely, would have a Material Adverse Effect.

(gg) The Company and each of its Subsidiaries have made and keep books, records and accounts, which, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the Company and its Subsidiaries in all material respects.

(hh) The Company maintains disclosure controls and procedures (as such is defined in Rule 13a-15(e) of the Exchange Act Rules) that comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that information required to be disclosed by the Company is accumulated and communicated to the Company’s management, including the Company’s principal executive officer and principal financial officer by others within the Company and is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms, and as of December 31, 2013, such disclosure controls and procedures were effective.

(ii) The minute books of the Company have been made available to the Underwriters and counsel for the Underwriters, and such books contain a complete summary of all meetings and actions of the board of directors (including each board committee) and shareholders of the Company (or analogous governing bodies and interest holders, as applicable), from January 1, 2009 through the date of this Agreement.

(jj) There is no franchise agreement, lease, contract, or other agreement or document required by the Securities Act or by the Rules and Regulations to be described in the General Disclosure Package and in the Prospectus or a document incorporated by reference therein or to be filed as an exhibit to the Registration Statements or a document incorporated by reference therein which is not so described or filed therein as required; and all descriptions of any such franchise agreements, leases, contracts, or other agreements or documents contained in the General Disclosure Package and in the Prospectus or in a document incorporated by reference therein are accurate and complete descriptions of such documents in all material respects. Other than as described in the General Disclosure Package, no such franchise agreement, lease, contract or other agreement has been suspended or terminated for convenience or default by the Company or any of the other parties thereto, and neither the Company nor any of its Subsidiaries has received notice of and the Company does not have knowledge of any such pending or threatened suspension or termination.

(kk) No relationship, direct or indirect, exists between or among the Company on the one hand, and the directors, officers, shareholders (or analogous interest holders), customers or suppliers of the Company or any of its affiliates on the other hand, which is required to be described in the General Disclosure Package and the Prospectus or a document incorporated by reference therein and which is not so described.

(ll) No person or entity has the right to require registration of shares of Common Stock or other securities of the Company or any of its Subsidiaries because of the filing or effectiveness of the Registration Statements or otherwise, except for persons and entities who have expressly waived such right in writing or who have been given timely and proper written notice and have failed to exercise such right within the time or times required under the terms and conditions of such right. Except as described in the General Disclosure Package, there are no persons with registration rights or similar rights to have any securities registered by the Company or any of its Subsidiaries under the Securities Act.

(mm) Neither the Company nor any of its Subsidiaries own any “margin securities” as that term is defined in Regulation U of the Board of Governors of the Federal Reserve System (the “Federal Reserve Board”), and none of the proceeds of the sale of the Stock will be used, directly or indirectly, for the purpose of purchasing or carrying any margin security, for the purpose of reducing or retiring any indebtedness which was originally incurred to purchase or carry any margin security or for any other purpose which might cause any of the Stock to be considered a “purpose credit” within the meanings of Regulation T, U or X of the Federal Reserve Board.

(nn) Neither the Company nor any of its Subsidiaries is a party to any contract, agreement or understanding with any person that would give rise to a valid claim against the Company or the Underwriters for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Stock or any transaction contemplated by this Agreement, the Registration Statements, the General Disclosure Package or the Prospectus.

(oo) The exercise price of each option issued under the Company’s stock option or other employee benefit plans has been no less than the fair market value of a share of common stock as determined on the date of grant of such option. All grants of options were validly issued and properly approved by the board of directors of the Company (or a duly authorized committee thereof) in material compliance with all applicable laws and regulations and recorded in the Company’s financial statements in accordance with GAAP and, to the Company’s knowledge, no such grants involved “back dating,” “forward dating” or similar practice with respect to the effective date of grant.

(pp) Except as described in the General Disclosure Package and the Prospectus, no Subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, 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 properties or assets to the Company or any other Subsidiary of the Company.

(qq) Since the date as of which information is given in the General Disclosure Package and the Prospectus through the date hereof, and except as set forth in the Pricing Prospectus, neither the Company nor any of its Subsidiaries has (i) issued or granted any securities other than options to purchase common stock pursuant to the Company’s stock option plan or securities issued upon the exercise of stock options or warrants in the ordinary course of business, (ii) incurred any material liability or obligation, direct or contingent, other than liabilities and obligations which were incurred in the ordinary course of business, (iii) entered into any material transaction other than in the ordinary course of business or (iv) declared or paid any dividend on its capital stock.

(rr) If applicable, all of the information provided to the Underwriters or to counsel for the Underwriters by the Company and its officers and directors in connection with letters, filings or other supplemental information provided to FINRA pursuant to NASD Conduct rule 2710 or 2720 is true, correct and complete.

(ss) The Company (i) has a non-affiliate, public common equity float of at least $150 million or a non-affiliate, public common equity float of at least $100 million and annual trading volume of at least three million shares and (ii) has been subject to the Exchange Act reporting requirements for a period of 36 months.

(tt) No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in either the General Disclosure Package or the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(uu) None of the Company or any of its Subsidiaries does business with the government of Cuba or with any person or affiliate located in Cuba within the meaning of Florida Statutes Section 517.075.

(vv) The Company is subject to and in compliance in all material respects with the reporting requirements of Section 13 or Section 15(d) of the Exchange Act. The Common Stock is registered pursuant to Section 12(b) or 12(g) of the Exchange Act and is listed on the Exchange, and the Company has taken no action designed to, or reasonably likely to have the effect of, terminating the registration of the Common Stock under the Exchange Act or delisting the Common Stock from the Exchange, nor has the Company received any notification that the Commission or FINRA is contemplating terminating such registration or listing.

(ww) The Company is in compliance in all material respects with all applicable provisions of the Sarbanes-Oxley Act of 2002 and all rules and regulations promulgated thereunder or implementing the provisions thereof (the “Sarbanes-Oxley Act”) that are in effect.

(xx) The Company is in compliance with all applicable corporate governance requirements set forth in the rules of the Exchange that are in effect.

(yy) Neither the Company nor any of its Subsidiaries nor, to the Company’s knowledge, any employee, or agent while acting on behalf of the Company or any Subsidiary, has (i) used any corporate funds for unlawful contributions, gifts, entertainment or other unlawful expenses relating to political activity, (ii) made any unlawful payment to foreign or domestic government officials or employees or to foreign or domestic political parties or campaigns from corporate funds, (iii) violated any provision of the Foreign Corrupt Practices Act of 1977, as amended or (iv) made any other unlawful payment.

(zz) There are no transactions, arrangements or other relationships between and/or among the Company, any of its affiliates (as such term is defined in Rule 405 of the Rules and Regulations) and any

unconsolidated entity, including, but not limited to, any structured finance, special purpose or limited purpose entity that could reasonably be expected to materially affect the Company’s liquidity or the availability of or requirements for its capital resources required to be described in the General Disclosure Package and the Prospectus or a document incorporated by reference therein which have not been described as required.

(aaa) There are no outstanding loans, advances (except normal advances for business expenses in the ordinary course of business) or guarantees of indebtedness by the Company or any of its Subsidiaries to or for the benefit of any of the officers or directors of the Company, any of its Subsidiaries or any of their respective family members, except as disclosed in the Registration Statements, the General Disclosure Package and the Prospectus. All transactions by the Company with office holders or control persons of the Company have been duly approved by the board of directors of the Company, or duly appointed committees or officers thereof, if and to the extent required under U.S. law.

(bbb) The statistical and market related data included in the Registration Statement, the General Disclosure Package and the Prospectus are based on or derived from sources that the Company believes to be reliable and accurate, and such data are consistent with the sources from which they are derived.

(ccc) The operations of the Company and its Subsidiaries are and have been conducted at all times in compliance in all material respects with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, applicable money laundering statutes and applicable rules and regulations thereunder (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 involving the Company or any of its Subsidiaries with respect to the Money Laundering Laws is pending, or to the Company’s knowledge, threatened.

(ddd) Neither the Company nor any of its Subsidiaries nor, to the Company’s knowledge, any director, officer, agent, employee or affiliate of the Company or any of its Subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); provided, however, that for purposes of this Section (ddd), no person shall be an affiliate of the Company solely by reason of owning less than a majority of any class of voting securities of the Company. The Company will not directly or indirectly use the proceeds of the offering, 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 currently subject to any U.S. sanctions administered by OFAC.

(eee) The Company and its Subsidiaries, individually and on a consolidated basis, are not as of the date hereof, and after giving effect to the transactions contemplated hereby to occur on the Closing Date, will not be Insolvent (as defined below). For purposes of this Section 3(eee), “Insolvent” means, with respect to any Person, (i) the present fair saleable value of such Person’s assets is less than the amount required to pay such Person’s total Indebtedness, (ii) such Person is unable to pay its debts and liabilities, subordinated, contingent or otherwise, as such debts and liabilities become absolute and matured, (iii) such Person intends to incur or believes that it will incur debts that would be beyond its ability to pay as such debts mature or (iv) such Person has unreasonably small capital with which to conduct the business in which it is engaged as such business is now conducted.

(fff) Neither the Company nor, to the Company’s knowledge, any of its affiliates (within the meaning of NASD Conduct Rule 2720(b)(1)(a)) directly or indirectly controls, is controlled by, or is under common control with, or is an associated person (within the meaning of Article I, Section 1(ee) of the By-laws of FINRA) of, any member firm of FINRA.

(ggg) None of Omeros Poland sp. z.o.o., Artemeros sp. z.o.o., or Omeros London Limited (collectively, the “Foreign Subsidiaries”) have any material assets or any liabilities, contingent or otherwise, other than any such liabilities that could not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

Any certificate signed by or on behalf of the Company and delivered to the Representative or to counsel for the Underwriters shall be deemed to be a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

3.PURCHASE, SALEAND DELIVERYOF OFFERED SECURITIES. On the basis of the representations, warranties and agreements herein contained, but subject to the terms and conditions herein set forth, the Company agrees to sell to the Underwriters, and the Underwriters agree, severally and not jointly, to purchase from the Company the respective numbers of shares of Firm Stock set forth opposite the names of the Underwriters inSchedule A hereto.

The purchase price per share to be paid by the Underwriters to the Company for the Stock will be $10.8675 per share (the “Purchase Price”).

The Company will deliver the Firm Stock to the Representative for the respective accounts of the several Underwriters, through the facilities of The Depository Trust Company, in each such case, issued in such names and in such denominations as the Representative may direct by notice in writing to the Company given at or prior to 12:00 Noon, New York time, on the second (2^nd) full business day preceding the Closing Date against payment of the aggregate Purchase Price therefor by wire transfer in federal (same day) funds to an account at a bank acceptable to the Representative payable to the order of the Company at the offices of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., One Financial Center, Boston, Masachusetts 02111. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligations of each Underwriter hereunder. The time and date of the delivery and closing shall be at 10:00 A.M., New York time, on March 19, 2014, in accordance with Rule15c6-1 of the Exchange Act. The time and date of such payment and delivery are herein referred to as the “Closing Date.” The Closing Date and the location of delivery of, and the form of payment for, the Firm Stock may be varied by agreement between the Company and the Representative.

For the purpose of covering anyover-allotments in connection with the distribution and sale of the Firm Stock as contemplated by the Prospectus, the Underwriters may purchase all or less than all of the Optional Stock. The price per share to be paid for the Optional Stock shall be the Purchase Price. The Company agrees to sell to the Underwriters the number of shares of Optional Stock specified in the written notice delivered by the Representative to the Company described below and the Underwriters agree, severally and not jointly, to purchase such shares of Optional Stock. The option granted hereby may be exercised as to all or any part of the Optional Stock at any time, and from time to time, not more than thirty (30) days subsequent to the date of this Agreement. No Optional Stock shall be sold and delivered unless the Firm Stock previously has been, or simultaneously is, sold and delivered. The right to purchase the Optional Stock or any portion thereof may be surrendered and terminated at any time upon notice by the Representative to the Company.

The option granted hereby may be exercised by written notice being given to the Company by the Representative setting forth the number of shares of the Optional Stock to be purchased by the Underwriters and the date and time for delivery of and payment for the Optional Stock. Each date and time for delivery of and payment for the Optional Stock (which may be the Closing Date, but not earlier) is herein called the “Option Closing Date” and shall in no event be earlier than two (2) business days nor later than five (5) business days after written notice is given. The Option Closing Date and the Closing Date are herein called the “Closing Dates.”

The Company will deliver the Optional Stock to the Representative for the respective accounts of the several Underwriters through the facilities of The Depository Trust Company issued in such names and in such denominations as the Representative may direct by notice in writing to the Company given at or prior to 12:00 Noon, New York time, on the second (2^nd) full business day preceding the Option Closing Date against payment of the aggregate Purchase Price therefor by wire transfer in federal (same day) funds to an account at a bank acceptable to the Representative payable to the order of the Company at the offices of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., One Financial Center, Boston, Masachusetts 02111. Time shall be of the essence, and delivery at the time and place specified pursuant to this Agreement is a further condition of the obligations of each Underwriter hereunder. The Option Closing Date and the location of delivery of, and the form of payment for, the Optional Stock may be varied by agreement between the Company and the Representative.

The several Underwriters propose to offer the Stock for sale upon the terms and conditions set forth in the Prospectus.

4.FURTHER AGREEMENTS OF THE COMPANY. The Company agrees with the several Underwriters:

(a) To prepare the Rule 462(b) Registration Statement, if necessary, in a form approved by the Representative and file such Rule 462(b) Registration Statement with the Commission by 10:00 P.M., New York time, on the date hereof, and the Company shall at the time of filing either pay to the Commission the filing fee for the Rule 462(b) Registration Statement or give irrevocable instructions for the payment of such fee pursuant to Rule 111(b) of the Rules and Regulations; to prepare the Prospectus in a form approved by the Representative containing information previously omitted at the time of effectiveness of the Registration Statement in reliance on Rule 430A, 430B or 430C of the Rules and Regulations and to file such Prospectus pursuant to Rule 424(b) of the Rules and Regulations not later than the second business (2^nd) day following the execution and delivery of this Agreement or, if applicable, such earlier time as may be required by Rule 430A of the Rules and Regulations; to notify the Representative immediately of the Company’s intention to file or prepare any supplement or amendment to any Registration Statement or to the Prospectus and to make no amendment or supplement to the Registration Statements, the General Disclosure Package or to the Prospectus to which the Representative shall reasonably object by notice to the Company after a reasonable period to review prior to the expiration of the Prospectus Delivery Period (as defined below); to advise the Representative, promptly after it receives notice thereof, of the time when any amendment to any Registration Statement has been filed or becomes effective or any supplement to the General Disclosure Package or the Prospectus or any amended Prospectus has been filed and to furnish the Underwriters with copies thereof; to file promptly all material required to be filed by the Company with the Commission pursuant to Rules 433(d) or 163(b)(2) of the Rules and Regulations, as the case may be; to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) of the Rules and Regulations) is required in connection with the offering or sale of the Stock (the “Prospectus Delivery Period”); prior to the expiration of the Prospectus Delivery Period, to advise the Representative, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus, of the suspension of the qualification of the Stock for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statements, the General Disclosure Package or the Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus or suspending any such qualification, and promptly to use its best efforts to obtain the withdrawal of such order.

(b) The Company represents and agrees that, unless it obtains the prior consent of the Representative, and each of the Underwriters represents and agrees that, unless it obtains the prior consent of the Company and the Representative, it has not made and will not make any offer relating to the Stock that would constitute a “free writing prospectus” as defined in Rule 405 of the Rules and Regulations (each, a “Permitted Free Writing Prospectus”);provided that the prior written consent of the Representative hereto shall be deemed to have been given in respect of the Issuer Free Writing Prospectuses included inSchedule C hereto. The Company represents that it has treated and agrees that it will treat each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, comply with the requirements of Rules 164 and 433 of the Rules and Regulations applicable to any Issuer Free Writing Prospectus, including the requirements relating to timely filing with the Commission, legending and record keeping and will not take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) of the Rules and Regulations a free writing prospectus prepared by or on behalf of such Underwriter that such Underwriter otherwise would not have been required to file thereunder.

(c) If at any time prior to the expiration of nine (9) months after the later of (i) the latest effective date of the Registration Statement or (ii) the date of the Prospectus, when a prospectus relating to the Stock is required to be delivered (or in lieu thereof, the notice referred to in Rule 173(a) of the Rules and Regulations) any event occurs or condition exists as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact, or omit to state any material fact necessary to make the statements therein, in light of the circumstances under which they were made when the Prospectus is delivered (or in lieu thereof, the notice referred to in Rule 173(a) of the Rules and

Regulations), not misleading, or if it is necessary at any time to amend or supplement any Registration Statement or the Prospectus or to file under the Exchange Act any document incorporated by reference in the Prospectus to comply with the Securities Act or the Exchange Act, that the Company will promptly notify the Representative thereof and upon their request will prepare an appropriate amendment or supplement or upon its request make an appropriate filing pursuant to Section 13 or 14 of the Exchange Act in form and substance reasonably satisfactory to the Representative that will correct such statement or omission or effect such compliance and will use its best efforts to have any amendment to any Registration Statement declared effective as soon as possible. The Company will furnish without charge to each Underwriter and to any dealer in securities as many copies as the Representative may from time to time reasonably request of such amendment or supplement. In case any Underwriter is required to deliver a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) of the Rules and Regulations) relating to the Stock nine (9) months or more after the later of (i) the latest effective date of the Registration Statement or (ii) the date of the Prospectus, the Company upon the request of the Representative will prepare promptly an amended or supplemented Prospectus as may be necessary to permit compliance with the requirements of Section 10(a)(3) of the Securities Act and deliver to such Underwriter as many copies as such Underwriter may reasonably request of such amended or supplemented Prospectus complying with Section 10(a)(3) of the Securities Act.

(d) If the General Disclosure Package is being used to solicit offers to buy the Stock at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur as a result of which, in the judgment of the Company or in the reasonable opinion of the Underwriters, it becomes necessary to amend or supplement the General Disclosure Package in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or to make the statements therein not conflict with the information contained or incorporated by reference in the Registration Statement then on file and not superseded or modified, or if it is necessary at any time to amend or supplement the General Disclosure Package to comply with any law, the Company promptly will either (i) prepare, file with the Commission (if required) and furnish to the Underwriters and any dealers an appropriate amendment or supplement to the General Disclosure Package or (ii) prepare and file with the Commission an appropriate filing under the Exchange Act which shall be incorporated by reference in the General Disclosure Package so that the General Disclosure Package as so amended or supplemented will not, in the light of the circumstances under which they were made, be misleading or conflict with the Registration Statement then on file, or so that the General Disclosure Package will comply with law.

(e) If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or will conflict with the information contained in the Registration Statement, Pricing Prospectus or Prospectus, including any document incorporated by reference therein and any prospectus supplement deemed to be a part thereof and not superseded or modified or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, the Company has promptly notified or will promptly notify the Representative so that any use of the Issuer Free Writing Prospectus may cease until it is amended or supplemented and has promptly amended or will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission. The foregoing sentence does not apply to statements in or omissions from any Issuer Free Writing Prospectus in reliance upon, and in conformity with, written information furnished to the Company through any Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriter’s Information (as defined in Section 17).

(f) To the extent not available on the Commission’s Electronic Data Gathering, Analysis and Retrieval system (“EDGAR”), to furnish promptly to the Representative and to counsel for the Underwriters a signed copy of each of the Registration Statements as originally filed with the Commission, and of each amendment thereto filed with the Commission, including all consents and exhibits filed therewith.

(g) To deliver promptly to the Representative in New York City such number of the following documents as the Representative shall reasonably request: (i) conformed copies of the Registration

Statements as originally filed with the Commission (in each case excluding exhibits), (ii) each Preliminary Prospectus, (iii) any Issuer Free Writing Prospectus, (iv) the Prospectus (the delivery of the documents referred to in clauses (i), (ii), (iii) and (iv) of this paragraph (g) to be made not later than 10:00 A.M., New York time, on the business day following the execution and delivery of this Agreement), (v) conformed copies of any amendment to the Registration Statement (excluding exhibits), (vi) any amendment or supplement to the General Disclosure Package or the Prospectus after the date hereof (the delivery of the documents referred to in clauses (v) and (vi) of this paragraph (g) to be made not later than 10:00 A.M., New York City time, on the business day following the date of such amendment or supplement) and (vii) any document incorporated by reference in the General Disclosure Package or the Prospectus (excluding exhibits thereto) (the delivery of the documents referred to in clause (vi) of this paragraph (g) to be made not later than 10:00 A.M., New York City time, on the business day following the date of such document).

(h) To make generally available to its shareholders as soon as practicable, but in any event not later than sixteen (16) months after the effective date of each Registration Statement (as defined in Rule 158(c) of the Rules and Regulations), an earnings statement of the Company and its Subsidiaries (which need not be audited) complying with Section 11(a) of the Securities Act and the Rules and Regulations (including, at the option of the Company, Rule 158).

(i) To take promptly from time to time such actions as the Representative may reasonably request to qualify the Stock for offering and sale under the securities or Blue Sky laws of such jurisdictions (domestic or foreign) as the Representative may designate and to continue such qualifications in effect, and to comply with such laws, for so long as required to permit the offer and sale of Stock in such jurisdictions;provided that the Company and its Subsidiaries shall not be obligated to qualify as foreign corporations in any jurisdiction in which they are not so qualified or to file a general consent to service of process in any jurisdiction.

(j) Upon request, during the period of two (2) years from the date hereof, to deliver to each of the Underwriters, (i) as soon as they are available, copies of all reports or other communications furnished to shareholders generally, and (ii) as soon as they are available, copies of any reports and financial statements furnished or filed with the Commission or any national securities exchange on which the Stock is listed. However, so long as the Company is subject to the reporting requirements of either Section 13 or Section 15(d) of the Exchange Act and is timely filing reports with the Commission on EDGAR, it is not required to furnish such reports or statements to the Underwriters.

(k) That the Company will not, for a period of ninety (90) days from the date of this Agreement, (the “Lock-Up Period”) without the prior written consent of the Representative, directly or indirectly offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, other than (i) the Company’s sale of the Stock hereunder, (ii) the issuance of restricted Common Stock or options to acquire Common Stock pursuant to the Company’s employee benefit plans, qualified stock option plans or other employee compensation plans as such plans are in existence on the date hereof and described in the Prospectus and (iii) the issuance of Common Stock pursuant to the valid exercises, vesting or settlements of options, warrants or rights outstanding on the date hereof. The Company will cause each officer and director listed inSchedule D to furnish to Cowen and Company, LLC, prior to the Closing Date, a letter, substantially in the form ofExhibit I hereto. The Company also agrees that during the Lock-Up Period, other than for the sale of the Stock hereunder, the Company will not file any registration statement, preliminary prospectus or prospectus, or any amendment or supplement thereto, under the Securities Act for any such transaction or which registers, or offers for sale, Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, except for (i) a registration statement on Form S-8 relating to employee benefit plans and (ii) any pre-effective amendments to the registration statement on Form S-3 (File No. 333-191779) filed by the Company with the Commission on October 17, 2013, any final prospectuses related thereto and any amendment or supplement thereof (provided however that the restrictions imposed by this paragraph (k) shall apply to any securities subject to such registration statement). Only to the extent that the rules of the FINRA relating to such extensions (or any successor rules thereto) remain in effect, the Company hereby agrees that (i) if it issues an earnings release or material news, or if a material event relating to the Company occurs, during the last seventeen (17) days of the Lock-Up Period, or (ii) if prior to the expiration of the Lock-Up Period, the Company announces that it will release earnings results during

the sixteen (16)-day period beginning on the last day of the Lock-Up Period, the restrictions imposed by this paragraph (k) or the letter shall continue to apply until the expiration of the eighteen (18)-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event. Notwithstanding the foregoing, the Lock-Up Period shall not be extended pursuant to the preceding sentence if (i) the shares of Common Stock are “actively traded securities” as defined in Regulation M of the Exchange Act, (ii) the Company meets the applicable requirements of paragraph (a)(1) of Rule 139 of the Rules and Regulations, in the manner contemplated by FINRA Conduct Rule 2711(f)(4) and (iii) the provisions of FINRA Conduct Rule 2711(f)(4) are not applicable to any research reports relating to the Company published or distributed by any of the Underwriters during the 15 days before or after the last day of the Lock-Up Period (before giving effect to such extension). The Company will provide the Representative and any co-managers and each shareholder subject to the Lock-Up Period with prior notice (in accordance with Section 15 herein) of any such announcement that gives rise to an extension of the Lock-Up Period, subject to the Underwriter’s agreement to hold such information in confidence prior to the public disclosure of the same.

(l) To supply the Representative with copies of all correspondence to and from, and all documents issued to and by, the Commission in connection with the registration of the Stock under the Securities Act or any of the Registration Statements, any Preliminary Prospectus or the Prospectus, or any amendment or supplement thereto or document incorporated by reference therein.

(m) Until the Representative shall have notified the Company of the completion of the resale of the Stock, that the Company will not, and will cause its affiliated purchasers (as defined in Regulation M under the Exchange Act) not to, either alone or with one or more other persons, bid for or purchase, for any account in which it or any of its affiliated purchasers has a beneficial interest, any Stock, or attempt to induce any person to purchase any Stock; and not to, and to cause its affiliated purchasers not to, make bids or purchase for the purpose of creating actual, or apparent, active trading in or of raising the price of the Stock.

(n) Use its reasonable efforts not to take any action prior to latest of the Closing Dates which would require the Prospectus to be amended or supplemented pursuant to Section 4(c).

(o) To at all times comply with all applicable provisions of the Sarbanes-Oxley Act in effect from time to time.

(p) To maintain, at its expense, a registrar and transfer agent for the Stock.

(q) To apply the net proceeds from the sale of the Stock as set forth in the Registration Statement, the General Disclosure Package and the Prospectus under the heading “Use of Proceeds,” and except as disclosed in the General Disclosure Package, the Company does not intend to use any of the proceeds from the sale of the Stock hereunder to repay any outstanding debt owed to any affiliate of any Underwriter. The Company shall manage its affairs and investments in such a manner as not to be or become an “investment company” within the meaning of the Investment Company Act and the rules and regulations thereunder.

(r) To use its reasonable best efforts to list, subject to notice of issuance, and to maintain the listing of the Stock on the Exchange.

(s) To use its reasonable best efforts to do and perform all things required to be done or performed under this Agreement by the Company prior to each Closing Date and to satisfy all conditions precedent to the delivery of the Firm Stock and the Optional Stock.

(t) Upon request of any Underwriter, to furnish, or cause to be furnished, to such Underwriter an electronic version of the Company’s trademarks, servicemarks and corporate logo for use on the website, if any, operated by such Underwriter for the purpose of facilitating the on-line offering of the Stock (the “License”);provided, however that the License shall be used solely for the purpose described above, is granted without any fee and may not be assigned or transferred.

5.PAYMENTOF EXPENSES. The Company agrees to pay, or reimburse if paid by any Underwriter, whether or not the transactions contemplated hereby are consummated or this Agreement is terminated: (a) the costs incident to the authorization, issuance, sale, preparation and delivery of the Stock and any taxes payable in that connection; (b) the costs incident to the registration of the Stock under the Securities Act; (c) the costs incident to the preparation, printing and distribution of the Registration Statements, the Base Prospectus, any Preliminary Prospectus, any Issuer Free Writing Prospectus, the General Disclosure Package, the Prospectus, any amendments, supplements and exhibits thereto or any document incorporated by reference therein and the costs of printing, reproducing and distributing the “Agreement Among Underwriters” between the Representative and the Underwriters, the Master Selected Dealers’ Agreement, the underwriters’ questionnaire, this Agreement and any closing documents by mail, telex or other means of communications; (d) the fees and expenses (including related fees and expenses of counsel for the Underwriters) incurred in connection with securing any required review by FINRA of the terms of the sale of the Stock and any filings made with FINRA (not to exceed $5,000 in the aggregate); (e) any applicable listing or other fees; (f) the fees and expenses (including related fees and expenses of counsel to the Underwriters) of qualifying the Stock under the securities laws of the several jurisdictions as provided in Section 4(i)) and of preparing, printing and distributing wrappers, Blue Sky Memoranda and Legal Investment Surveys (not to exceed $2,000 in the aggregate); (g) the cost of preparing and printing stock certificates; (h) all fees and expenses of the registrar and transfer agent of the Stock; (i) the costs and expenses (including, without limitation, any damages or other amounts payable in connection with the legal or contractual liability) associated with the reforming of any contracts for sale of the Stock made by the Underwriters caused by a breach of the representation contained in Section 2(c); (j) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Stock, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, 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 with the prior approval of the Company, travel and lodging expenses of the officers of the Company and such consultants, including the cost of any aircraft chartered in connection with the road show; and (k) all other costs and expenses incident to the offering of the Stock or the performance of the obligations of the Company under this Agreement (including, without limitation, the fees and expenses of the Company’s counsel and the Company’s independent accountants;provided that, except to the extent otherwise provided in this Section 5 and in Sections 9 and 10 the Underwriters shall pay their own costs and expenses incurred in connection with the transactions contemplated hereby, including the fees and expenses of their counsel, any transfer taxes on the resale of any Stock by them and the expenses of advertising any offering of the Stock made by the Underwriters.

6.CONDITIONSOF UNDERWRITERS’ OBLIGATIONS. The respective obligations of the several Underwriters hereunder are subject to the accuracy, when made and as of the Applicable Time and on such Closing Date, of the representations and warranties of the Company contained herein, to the accuracy of the statements of the Company made in any certificates pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder, and to each of the following additional terms and conditions:

(a) The Registration Statements have become effective under the Securities Act, and no stop order suspending the effectiveness of any Registration Statement or any part thereof, preventing or suspending the use of any Base Prospectus, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus or any part thereof shall have been issued and no proceedings for that purpose or pursuant to Section 8A under the Securities Act shall have been initiated or threatened by the Commission, and all requests for additional information on the part of the Commission (to be included or incorporated by reference in the Registration Statements or the Prospectus or otherwise) shall have been complied with to the reasonable satisfaction of the Representative; the Rule 462(b) Registration Statement, if any, each Issuer Free Writing Prospectus and the Prospectus shall have been filed with the Commission within the applicable time period prescribed for such filing by, and in compliance with, the Rules and Regulations and in accordance with Section 4(a), and the Rule 462(b) Registration Statement, if any, shall have become effective immediately upon its filing with the Commission; and FINRA shall have raised no objection to the fairness and reasonableness of the terms of this Agreement or the transactions contemplated hereby.

(b) None of the Underwriters shall have discovered and disclosed to the Company on or prior to such Closing Date that any Registration Statement or any amendment or supplement thereto contains an untrue statement of a fact which, in the opinion of counsel for the Underwriters, is material or omits to state any fact which, in the opinion of such counsel, is material and is required to be stated therein or is necessary to make the statements therein not misleading, or that the General Disclosure Package, any Issuer Free

Writing Prospectus or the Prospectus or any amendment or supplement thereto contains an untrue statement of fact which, in the opinion of such counsel, is material or omits to state any fact which, in the opinion of such counsel, is material and is necessary in order to make the statements, in the light of the circumstances in which they were made, not misleading.

(c) All corporate proceedings and other legal matters incident to the authorization, form and validity of each of this Agreement, the Stock, the Registration Statements, the General Disclosure Package, each Issuer Free Writing Prospectus and the Prospectus and all other legal matters relating to this Agreement and the transactions contemplated hereby shall be reasonably satisfactory in all material respects to counsel for the Underwriters, and the Company shall have furnished to such counsel all documents and information that they may reasonably request to enable them to pass upon such matters.

(d) Covington & Burling LLP shall have furnished to the Representative such counsel’s written opinion, as counsel to the Company, addressed to the Underwriters and dated such Closing Date, in form and substance reasonably satisfactory to the Representative and substantially as set forth onExhibit II hereto.

(e) Marcia S. Kelbon, Vice President, Patent & General Counsel of the Company, shall have furnished to the Representative such counsel’s written opinion, as intellectual property and General Counsel to the Company, addressed to the Underwriters and dated such Closing Date, in form and substance reasonably satisfactory to the Representative and substantially as set forth onExhibit III hereto.

(f) Mark A. Metcalf, Associate General Counsel of the Company, shall have furnished to the Representative such counsel’s written opinion, as counsel to the Company, addressed to the Underwriters and dated such Closing Date, in form and substance reasonably satisfactory to the Representative and substantially as set forth onExhibit IV hereto

(g) The Company shall have furnished to the Representative a certificate, dated such Closing Date, of its Chairman and Chief Executive Officer and its Vice President, Regulatory Affairs and Quality Systems in form and substance reasonably satisfactory to the Representative and substantially as set forth onExhibit V hereto.

(h) The Representative shall have received from Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., counsel for the Underwriters, such opinion or opinions, dated such Closing Date, with respect to such matters as the Underwriters may reasonably require, and the Company shall have furnished to such counsel such documents as they request for enabling them to pass upon such matters.

(i) At the time of the execution of this Agreement, the Representative shall have received from Ernst & Young LLP a letter, addressed to the Underwriters, executed and dated such date, in form and substance satisfactory to the Representative (i) confirming that they are an independent registered accounting firm with respect to the Company and its Subsidiaries within the meaning of the Securities Act and the Rules and Regulations and rules and regulations of the PCAOB and (ii) stating the conclusions and findings of such firm, of the type ordinarily included in accountants’ “comfort letters” to underwriters, with respect to the financial statements and certain financial information contained or incorporated by reference in the Registration Statements, the General Disclosure Package and the Prospectus.

(j) On the effective date of any post-effective amendment to any Registration Statement and on such Closing Date, the Representative shall have received a letter (the “bring-down letter”) from Ernst & Young LLP addressed to the Underwriters and dated such Closing Date confirming, as of the date of the bring-down letter (or, with respect to matters involving changes or developments since the respective dates as of which specified financial information is given in the General Disclosure Package and the Prospectus, as the case may be, as of a date not more than three (3) business days prior to the date of the bring-down letter), the conclusions and findings of such firm, of the type ordinarily included in accountants’ “comfort letters” to underwriters, with respect to the financial information and other matters covered by its letter delivered to the Representative concurrently with the execution of this Agreement pursuant to paragraph (i) of this Section 6.

(k) The Company shall have furnished to the Representative a certificate, dated such Closing Date, of its Chairman of the Board and Chief Executive Officer and its Vice President, Patent & General Counsel stating that (i) such officers have examined the Registration Statement, the General Disclosure Package, any Permitted Free Writing Prospectus and the Prospectus and, in their opinion, the Registration Statements and each amendment thereto, at the Applicable Time, as of the date of this Agreement and as of such Closing Date did not include any untrue statement of a material fact and did not omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, and the General Disclosure Package, as of the Applicable Time and as of such Closing Date, any Permitted Free Writing Prospectus as of its date and as of such Closing Date, the Prospectus and each amendment or supplement thereto, as of the respective date thereof and as of such Closing Date, did not include any untrue statement of a material fact and did not omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances in which they were made, not misleading, (ii) since the effective date of the Initial Registration Statement, no event has occurred which should have been set forth in a supplement or amendment to the Registration Statements, the General Disclosure Package or the Prospectus that has not been so set forth therein, (iii) to the best of their knowledge after reasonable investigation, as of such Closing Date, the representations and warranties of the Company in this Agreement are true and correct and the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date, and (iv) there has not been, subsequent to the date of the most recent audited financial statements included or incorporated by reference in the General Disclosure Package, any material adverse change in the financial position or results of operations of the Company and its Subsidiaries, or any change or development that, singularly or in the aggregate, would involve a material adverse change or a prospective material adverse change, in or affecting the condition (financial or otherwise), results of operations, business, assets or prospects of the Company and its Subsidiaries taken as a whole, except as set forth in the Prospectus; it being understood that the certifications provided by the Vice President, Patent & General Counsel pursuant to this Section 6(k) will exclude the financial statements and the notes thereto, the financial schedules and other financial data and information included or incorporated or deemed incorporated by reference in the Registration Statement, the General Disclosure Package or the Prospectus.

(l) Since the date of the latest audited financial statements included in the General Disclosure Package or incorporated by reference in the General Disclosure Package as of the date hereof, (i) neither the Company nor any of its Subsidiaries shall have sustained any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth in the General Disclosure Package, and (ii) there shall not have been any change in the capital stock or long-term debt of the Company or any of its Subsidiaries (other than stock option and warrant exercises and stock repurchases in the ordinary course of business and repayments of existing indebtedness), or any change, or any development involving a prospective change, in or affecting the business, general affairs, management, financial position, shareholders’ equity or results of operations of the Company and its Subsidiaries, otherwise than as set forth in the General Disclosure Package, the effect of which, in any such case described in clause (i) or (ii) of this paragraph (l), is, in the judgment of the Representative, so material and adverse as to make it impracticable or inadvisable to proceed with the sale or delivery of the Stock on the terms and in the manner contemplated in the General Disclosure Package.

(m) No action shall have been taken and no law, statute, rule, regulation or order shall have been enacted, adopted or issued by any governmental agency or body which would prevent the issuance or sale of the Stock or materially and adversely affect or could be reasonably expected to materially and adversely affect the business or operations of the Company; and no injunction, restraining order or order of any other nature by any federal or state court of competent jurisdiction shall have been issued which would prevent the issuance or sale of the Stock or materially and adversely affect or could reasonably be expected to materially and adversely affect the business or operations of the Company.

(n) Subsequent to the execution and delivery of this Agreement there shall not have occurred any of the following: (i) trading in securities generally on the New York Stock Exchange, Nasdaq Global Market or the American Stock Exchange or in the over-the-counter market, or trading in any securities of the Company on any exchange or in the over-the-counter market, shall have been suspended or materially limited, or minimum or maximum prices or maximum range for prices shall have been established on any

such exchange or such market by the Commission, by such exchange or market or by any other regulatory body or governmental authority having jurisdiction, (ii) a banking moratorium shall have been declared by federal or state authorities or a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States, (iii) the United States shall have become engaged in hostilities, or the subject of an act of terrorism, or there shall have been an outbreak of or escalation in hostilities involving the United States, or there shall have been a declaration of a national emergency or war by the United States, or (iv) there shall have occurred such a material adverse change in general economic, political or financial conditions (or the effect of international conditions on the financial markets in the United States shall be such), in the case of clauses (i), (ii), (iii) and (iv) above, so as to make it, in the judgment of the Representative, impracticable or inadvisable to proceed with the sale or delivery of the Stock on the terms and in the manner contemplated in the General Disclosure Package and the Prospectus.

(o) The Exchange shall have approved the Stock for listing therein, subject only to official notice of issuance.

(p) The Representative shall have received on and as of such Closing Date satisfactory evidence of the good standing of the Company and its Subsidiaries in their respective jurisdictions of organization and their good standing as foreign entities in such other jurisdictions as the Representative may reasonably request, in each case in writing or any standard form of telecommunication from the appropriate governmental authorities of such jurisdictions.

(q) The Representative shall have received the written agreements, substantially in the form ofExhibit I hereto, of the officers and directors of the Company listed inSchedule D to this Agreement.

(r) On or prior to such Closing Date, the Company shall have furnished to the Representative such further certificates and documents as the Representative may reasonably request.

All opinions, letters, evidence and certificates mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriters.

7. INDEMNIFICATIONAND CONTRIBUTION.

(a) The Company shall indemnify and hold harmless:

each Underwriter, its directors, officers, managers, members, employees, representatives and agents and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act (collectively the “Underwriter Indemnified Parties,” and each an “Underwriter Indemnified Party”) against any loss, claim, damage, expense or liability whatsoever (or any action, investigation or proceeding in respect thereof), joint or several, to which such Underwriter Indemnified Party may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, expense, liability, action, investigation or proceeding arises out of or is based upon (A) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, any Issuer Free Writing Prospectus, any “issuer information” filed or required to be filed pursuant to Rule 433(d) of the Rules and Regulations, any Registration Statement or the Prospectus, or in any amendment or supplement thereto or document incorporated by reference therein, or (B) the omission or alleged omission to state in any Preliminary Prospectus, any Issuer Free Writing Prospectus, any “issuer information” filed or required to be filed pursuant to Rule 433(d) of the Rules and Regulations, any Registration Statement or the Prospectus, or in any amendment or supplement thereto or document incorporated by reference therein, a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they are made, not misleading, and shall reimburse each Underwriter Indemnified Party promptly upon demand for any legal fees or other expenses reasonably incurred by that Underwriter Indemnified Party in connection with investigating, or preparing to defend, or defending against, or appearing as a third party witness in respect of, or otherwise incurred in connection with, any such loss, claim, damage, expense, liability, action, investigation or proceeding, as such fees and expenses are incurred;provided,however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage, expense or liability arises out of or is based upon an untrue statement or alleged

untrue statement in, or omission or alleged omission from any Preliminary Prospectus, any Registration Statement or the Prospectus, or any such amendment or supplement thereto, or any Issuer Free Writing Prospectus made in reliance upon and in conformity with written information furnished to the Company through any Representative by or on behalf of any Underwriter specifically for use therein, which information the parties hereto agree is limited to the Underwriter’s Information (as defined in Section 17).

The indemnity agreement in this Section 7(a) is not exclusive and is in addition to each other liability which the Company might have under this Agreement or otherwise, and shall not limit any rights or remedies which may otherwise be available under this Agreement, at law or in equity to any Underwriter Indemnified Party.

(b) Each Underwriter, severally and not jointly, shall indemnify and hold harmless the Company and its directors, its officers and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act (collectively the “Company Indemnified Parties” and each a “Company Indemnified Party”) against any loss, claim, damage, expense or liability whatsoever (or any action, investigation or proceeding in respect thereof), joint or several, to which such Company Indemnified Party may become subject, under the Securities Act or otherwise, insofar as such loss, claim, damage, expense, liability, action, investigation or proceeding arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, any Issuer Free Writing Prospectus, any “issuer information” filed or required to be filed pursuant to Rule 433(d) of the Rules and Regulations, any Registration Statement or the Prospectus, or in any amendment or supplement thereto or document incorporated by reference therein, or (ii) the omission or alleged omission to state in any Preliminary Prospectus, any Issuer Free Writing Prospectus, any “issuer information” filed or required to be filed pursuant to Rule 433(d) of the Rules and Regulations, any Registration Statement or the Prospectus, or in any amendment or supplement thereto or document incorporated by reference therein, a material fact required to be stated therein or necessary to make the statements therein in light of the circumstances under which they are made not misleading, but in each case only to the extent that the untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information furnished to the Company through any Representative by or on behalf of that Underwriter specifically for use therein, which information the parties hereto agree is limited to the Underwriter’s Information as defined in Section 17, and shall reimburse the Company Indemnified Parties for any legal or other expenses reasonably incurred by such party in connection with investigating or preparing to defend or defending against or appearing as third party witness in connection with any such loss, claim, damage, liability, action, investigation or proceeding, as such fees and expenses are incurred. This indemnity agreement is not exclusive and will be in addition to any liability which the Underwriters might otherwise have and shall not limit any rights or remedies which may otherwise be available under this Agreement, at law or in equity to the Company Indemnified Parties.

(c) Promptly after receipt by an indemnified party under this Section 7 of notice of the commencement of any action, the indemnified party shall, if a claim in respect thereof is to be made against an indemnifying party under this Section 7, notify such indemnifying party in writing of the commencement of that action;provided, however, that the failure to notify the indemnifying party shall not relieve it from any liability which it may have under this Section 7 except to the extent it has been materially prejudiced by such failure; and,provided, further, that the failure to notify an indemnifying party shall not relieve it from any liability which it may have to an indemnified party otherwise than under this Section 7. If any such action shall be brought against an indemnified party, and it shall notify the indemnifying party thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it wishes, jointly with any other similarly notified indemnifying party, to assume the defense of such action with counsel reasonably satisfactory to the indemnified party (which counsel shall not, except with the written consent of the indemnified party, be counsel to the indemnifying party). After notice from the indemnifying party to the indemnified party of its election to assume the defense of such action, except as provided herein, the indemnifying party shall not be liable to the indemnified party under Section 7 for any legal or other expenses subsequently incurred by the indemnified party in connection with the defense of such action other than reasonable costs of investigation;provided, however, that any indemnified party shall have the right to employ separate counsel in any such action and to participate in the defense of such action but the fees and expenses of such counsel (other than reasonable costs of investigation) shall be at the expense of such indemnified party unless (i) the employment thereof has been specifically authorized in

writing by the Company in the case of a claim for indemnification under Section 7(a) or the Representative in the case of a claim for indemnification under Section 7(b), (ii) such indemnified party shall have been advised by its counsel that there may be one or more legal defenses available to it which are different from or additional to those available to the indemnifying party, or (iii) the indemnifying party has failed to assume the defense of such action and employ counsel reasonably satisfactory to the indemnified party within a reasonable period of time after notice of the commencement of the action or the indemnifying party does not diligently defend the action after assumption of the defense, in which case, if such indemnified party notifies the indemnifying party in writing that it elects to employ separate counsel at the expense of the indemnifying party, the indemnifying party shall not have the right to assume the defense of (or, in the case of a failure to diligently defend the action after assumption of the defense, to continue to defend) such action on behalf of such indemnified party and the indemnifying party shall be responsible for legal or other expenses subsequently and reasonably incurred by such indemnified party in connection with the defense of such action;provided,however, that the indemnifying party shall not, in connection with any one such action or separate but substantially similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, be liable for the reasonable fees and expenses of more than one separate firm of attorneys at any time for all such indemnified parties (in addition to any local counsel), which firm shall be designated in writing by the Representative if the indemnified parties under this Section 7 consist of any Underwriter Indemnified Party or by the Company if the indemnified parties under this Section 7 consist of any Company Indemnified Parties. Subject to this Section 7(c), the amount payable by an indemnifying party under Section 7 shall include (x) reasonable legal fees and expenses of counsel to the indemnified party and any other expenses in investigating, or preparing to defend or defending against, or appearing as a third party witness in respect of, or otherwise incurred in connection with, any action, investigation, proceeding or claim, and (y) all amounts paid in settlement of any of the foregoing. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of judgment with respect to any pending or threatened action or any claim whatsoever, in respect of which indemnification or contribution could be sought under this Section 7 (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party in form and substance reasonably satisfactory to such indemnified party from all liability arising out of such action or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party. Subject to the provisions of the following sentence, no indemnifying party shall be liable for settlement of any pending or threatened action or any claim whatsoever that is effected without its written consent (which consent shall not be unreasonably withheld or delayed), but if settled with its written consent, if its consent has been unreasonably withheld or delayed or if there be a judgment for the plaintiff in any such matter, the indemnifying party agrees to indemnify and hold harmless any indemnified party from and against any loss or liability by reason of such settlement or judgment. In addition, if at any time an indemnified party shall have requested that an indemnifying party reimburse the indemnified party for reasonable fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 7(a) or 7(b) effected without its written consent if (i) such settlement is entered into more than forty-five (45) days after receipt by such indemnifying party of the request for reimbursement, (ii) such indemnifying party shall have received notice of the terms of such settlement at least thirty (30) days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

(d) If the indemnification provided for in this Section 7 is unavailable or insufficient to hold harmless an indemnified party under Section 7(a) or 7(b), then each indemnifying party shall, in lieu of indemnifying such indemnified party, contribute to the amount paid, payable or otherwise incurred by such indemnified party as a result of such loss, claim, damage, expense or liability (or any action, investigation or proceeding in respect thereof), as incurred, (i) in such proportion as shall be appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other from the offering of the Stock, or (ii) if the allocation provided by clause (i) of this Section 7(d) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) of this Section 7(d) but also the relative fault of the Company on the one hand and the Underwriters on the other with respect to the statements, omissions, acts or failures to act which resulted in such loss, claim, damage, expense or liability (or any action, investigation or proceeding in respect thereof) 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 with respect to such offering shall be deemed to be in the same proportion as the total net proceeds from the offering of the Stock purchased under this Agreement (before deducting expenses) received by the Company bear to the total underwriting discounts and commissions received by the Underwriters with respect to the Stock purchased under this Agreement, in each case as set forth in the table on the cover page of the Prospectus. The relative fault of the Company on the one hand and the Underwriters on the other shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or the Underwriters on the other, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such untrue statement, omission, act or failure to act; provided that the parties hereto agree that the written information furnished to the Company by any Representative by or on behalf of the Underwriters for use in the Preliminary Prospectus, any Registration Statement or the Prospectus, or in any amendment or supplement thereto, consists solely of the Underwriter’s Information as defined in Section 17.

(e) The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to Section 7(d) above were to be determined by pro rata allocation or by any other method of allocation which does not take into account the equitable considerations referred to in Section 7(d) above. The amount paid or payable by an indemnified party as a result of the loss, claim, damage, expense, liability, action, investigation or proceeding referred to in Section 7(d) above shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating, preparing to defend or defending against or appearing as a third party witness in respect of, or otherwise incurred in connection with, any such loss, claim, damage, expense, liability, action, investigation or proceeding. Notwithstanding the provisions of this Section 7, no Underwriters shall be required to contribute any amount in excess of the total underwriting discounts and commissions received by such Underwriter with respect to the offering of the Stock exceeds the amount of any damages which the Underwriter has otherwise paid or become liable to pay by reason of any untrue or alleged untrue statement, omission or alleged omission, act or alleged act or failure to act or alleged failure to act. No Person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any Person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute as provided in this Section 7 are several in proportion to their respective underwriting obligations and not joint.

8.TERMINATION. The obligations of the Underwriters hereunder may be terminated by the Representative, in its absolute discretion by notice given to the Company prior to delivery of and payment for the Firm Stock if, prior to that time, any of the events described in Sections 6(l), 6(m) or 6(n) have occurred or if the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement.

9.REIMBURSEMENTOF UNDERWRITERS’ EXPENSES. Notwithstanding anything to the contrary in this Agreement, if (a) this Agreement shall have been terminated pursuant to Section 8 or 10, (b) the Company shall fail to tender the Stock for delivery to the Underwriters for any reason not permitted under this Agreement, (c) the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement or (d) the sale of the Stock is not consummated because any condition to the obligations of the Underwriters set forth herein is not satisfied or because of the refusal, inability or failure on the part of the Company to perform any agreement herein or to satisfy any condition or to comply with the provisions hereof, then in addition to the payment of amounts in accordance with Section 5, the Company shall, pro rata based on the number of shares of Stock it agreed to sell hereunder, reimburse the Underwriters for the fees and expenses of Underwriters’ counsel and for such other out-of-pocket expenses as shall have been reasonably incurred by them in connection with this Agreement and the proposed purchase of the Stock, including, without limitation, travel and lodging expenses of the Underwriters, and upon demand the Company shall pay the full amount thereof to the Representative;provided that if this Agreement is terminated pursuant to Section 10 by reason of the default of one or more Underwriters, the Company shall not be obligated to reimburse any defaulting Underwriter on account of expenses to the extent incurred by such defaulting Underwriterprovided further that the foregoing shall not limit any reimbursement obligation of the Company to any non-defaulting Underwriter under this Section 9.

10.SUBSTITUTIONOF UNDERWRITERS. If any Underwriter or Underwriters shall default in its or their obligations to purchase shares of Stock hereunder on any Closing Date and the aggregate number of shares which such defaulting Underwriter or Underwriters agreed but failed to purchase does not exceed ten percent (10%) of the total number of

shares to be purchased by all Underwriters on such Closing Date, the other Underwriters shall be obligated severally, in proportion to their respective commitments hereunder, to purchase the shares which such defaulting Underwriter or Underwriters agreed but failed to purchase on such Closing Date. If any Underwriter or Underwriters shall so default and the aggregate number of shares with respect to which such default or defaults occur is more than ten percent (10%) of the total number of shares to be purchased by all Underwriters on such Closing Date and arrangements satisfactory to the Representative and the Company for the purchase of such shares by other persons are not made withinforty-eight (48) hours after such default, this Agreement shall terminate.

If the remaining Underwriters or substituted Underwriters are required hereby or agree to take up all or part of the shares of Stock of a defaulting Underwriter or Underwriters on such Closing Date as provided in this Section 10, (i) the Company shall have the right to postpone such Closing Date for a period of not more than five (5) full business days in order that the Company may effect whatever changes may thereby be made necessary in the Registration Statements or the Prospectus, or in any other documents or arrangements, and the Company agrees promptly to file any amendments to the Registration Statements or supplements to the Prospectus which may thereby be made necessary, and (ii) the respective numbers of shares to be purchased by the remaining Underwriters or substituted Underwriters shall be taken as the basis of their underwriting obligation for all purposes of this Agreement. Nothing herein contained shall relieve any defaulting Underwriter of its liability to the Company or the other Underwriters for damages occasioned by its default hereunder. Any termination of this Agreement pursuant to this Section 10 shall be without liability on the part of anynon-defaulting Underwriter or the Company, except that the representations, warranties, covenants, indemnities, agreements and other statements set forth in Section 2, the obligations with respect to expenses to be paid or reimbursed pursuant to Sections 5 and 9 and the provisions of Section 7 and Sections 12 through 21, inclusive, shall not terminate and shall remain in full force and effect.

11.ABSENCEOF FIDUCIARY RELATIONSHIP.The Company acknowledges and agrees that:

(a) each Underwriter’s responsibility to the Company is solely contractual in nature, the Representative has been retained solely to act as underwriter in connection with the sale of the Stock and no fiduciary, advisory or agency relationship between the Company and the Representative has been created in respect of any of the transactions contemplated by this Agreement, irrespective of whether the Representative has advised or is advising the Company on other matters;

(b) the price of the Stock set forth in this Agreement was established by the Company following discussions and arms-length negotiations with the Representative and the Company is capable of evaluating and understanding, and understands and accepts, the terms, risks and conditions of the transactions contemplated by this Agreement;

(c) it has been advised that the Representative and its affiliates are engaged in a broad range of transactions which may involve interests that differ from those of the Company and that the Representative has no obligation to disclose such interests and transactions to the Company by virtue of any fiduciary, advisory or agency relationship; and

(d) it waives, to the fullest extent permitted by law, any claims it may have against the Representative for breach of fiduciary duty or alleged breach of fiduciary duty and agrees that the Representative shall have no liability (whether direct or indirect) to the Company in respect of such a fiduciary duty claim or to any person asserting a fiduciary duty claim on behalf of or in right of the Company, including shareholders, employees or creditors of the Company.

12.SUCCESSORS; PERSONS ENTITLEDTO BENEFITOF AGREEMENT. This Agreement shall inure to the benefit of and be binding upon the several Underwriters, the Company and their respective successors and assigns. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, other than the persons mentioned in the preceding sentence, any legal or equitable right, remedy or claim under or in respect of this Agreement, or any provisions herein contained, this Agreement and all conditions and provisions hereof being intended to be and being for the sole and exclusive benefit of such persons and for the benefit of no other person; except that the representations, warranties, covenants, agreements and indemnities of the Company contained in this Agreement shall also be for the benefit of the Underwriter Indemnified Parties, and the indemnities of the several Underwriters shall be for the benefit of the Company Indemnified Parties. It is understood that each Underwriter’s responsibility to the Company is solely contractual in nature and the Underwriters do not owe the Company, or any other party, any fiduciary duty as a result of this Agreement. No purchaser of any of the Stock from any Underwriter shall be deemed to be a successor or assign by reason merely of such purchase.

13.SURVIVALOF INDEMNITIES, REPRESENTATIONS, WARRANTIES,ETC.The respective indemnities, covenants, agreements, representations, warranties and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by them respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation made by or on behalf of any Underwriter, the Company or any person controlling any of them and shall survive delivery of and payment for the Stock. Notwithstanding any termination of this Agreement, including without limitation any termination pursuant to Section 8 or Section 10, the indemnities, covenants, agreements, representations, warranties and other statements forth in Sections 2, 5, 7 and 9 and Sections 11 through 21, inclusive, of this Agreement shall not terminate and shall remain in full force and effect at all times.

14.NOTICES. All statements, requests, notices and agreements hereunder shall be in writing, and:

(a) if to the Underwriters, shall be delivered or sent by mail, telex, facsimile transmission or email to Cowen and Company, LLC, Attention: Head of Equity Capital Markets, Fax: 646-562-1249, with a copy to the General Counsel, Fax: 646-562-1124; and

(b) if to the Company shall be delivered or sent by mail, telex, facsimile transmission or email to Omeros Corporation Attention: Greg Demopulos and Marcia Kelbon, Fax: (206) 676-5005, email: gdemopulos@omeros.com; mkelbon@omeros.com;

provided, however, that any notice to an Underwriter pursuant to Section 7 shall be delivered or sent by mail, or facsimile transmission to such Underwriter at its address set forth in its acceptance telex to the Representative, which address will be supplied to any other party hereto by the Representative upon request. Any such statements, requests, notices or agreements shall take effect at the time of receipt thereof.

15.DEFINITIONOF CERTAIN TERMS. For purposes of this Agreement, (a) “business day” means any day on which the Exchange is open for trading and (b) “Subsidiary” has the meaning set forth in Rule 405 of the Rules and Regulations but in no event shall “Subsidiary” include the Foreign Subsidiaries.

16.GOVERNING LAWAND JURISDICTION. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, including without limitation Section 5-1401 of the New York General Obligations.The Company irrevocably (a) submits to the non-exclusive jurisdiction of the federal and state courts in the Borough of Manhattan in The City of New York for the purpose of any suit, action or other proceeding arising out of this Agreement or the transactions contemplated by this Agreement, the Registration Statements and any Preliminary Prospectus or the Prospectus, (b) agrees that all claims in respect of any such suit, action or proceeding may be heard and determined by any such court, (c) waives to the fullest extent permitted by applicable law, any immunity from the jurisdiction of any such court or from any legal process, (d) agrees not to commence any such suit, action or proceeding other than in such courts, and (e) waives, to the fullest extent permitted by applicable law, any claim that any such suit, action or proceeding is brought in an inconvenient forum.

17.UNDERWRITERS’ INFORMATION. The parties hereto acknowledge and agree that, for all purposes of this Agreement, the Underwriters’ Information consists solely of the following information in the Prospectus: (i) the last paragraph on the front cover page concerning the terms of the offering by the Underwriters; and (ii) the statements concerning the Underwriters contained in the ninth through twelfth paragraphs under the heading “Underwriting.”

18.AUTHORITYOFTHE REPRESENTATIVE. In connection with this Agreement, you will act for and on behalf of the several Underwriters, and any action taken under this Agreement by the Representative, will be binding on all the Underwriters.

19.PARTIAL UNENFORCEABILITY. The invalidity or unenforceability of any section, paragraph, clause or provision of this Agreement shall not affect the validity or enforceability of any other section, paragraph, clause or provision hereof. If any section, paragraph, clause or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

20.GENERAL. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. In this Agreement, the masculine, feminine and neuter genders and the singular and the plural include one another. The section headings in this Agreement are for the convenience of the parties only and will not affect the construction or interpretation of this Agreement. This Agreement may be amended or modified, and the observance of any term of this Agreement may be waived, only by a writing signed by the Company and the Representative.

21.COUNTERPARTS. This Agreement may be signed in any number of counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

If the foregoing is in accordance with your understanding of the agreement between the Company and the several Underwriters, kindly indicate your acceptance in the space provided for that purpose below.


Very truly yours,

OMEROS CORPORATION

By:		/s/ Gregory A. Demopolus, M.D.
		Name:
		Title:

Accepted as of

the date first above written:

COWENAND COMPANY, LLC

Acting on its own behalf

and as Representative of the several

Underwriters referred to in the

foregoing Agreement.

By: COWENAND COMPANY, LLC



By:		/s/ Jason Fenton
Name:		Jason Fenton
Title:		Managing Director

SCHEDULE A


Name	Number of Shares of Firm Stock to be Purchased		Number of Shares of Optional Stock to be Purchased
Cowen and Company, LLC		1,673,915		251,090

Wedbush Securities Inc.		760,869		114,130

Needham & Company, LLC		273,913		41,086

Maxim Group LLC		121,739		18,260

WBB Securities LLC		121,739		18,260

MLV & Co. LLC		91,304		13,695

Total		3,043,479		456,521

SCHEDULE B

Pricing Information

Number of shares of Firm Stock: 3,043,479

Number of shares of Optional Stock: 456,521

Price per share: $11.50

SCHEDULE C

General Use Free Writing Prospectuses

None.

SCHEDULE D

Gregory A. Demopulos

Michael A. Jacobsen

Marcia Kelbon

Ray Aspiri

Aspiri Enterprises LLC

Thomas J. Cable

Peter Demopulos

Arnold C. Hanish

Leroy E. Hood

The Demopulos Family Trust

Exhibit I

[Form of Lock-Up Agreement]

March , 2014

Cowen and Company, LLC

As representative of the

several Underwriters

c/o Cowen and Company, LLC

599 Lexington Avenue

New York, New York 10022

Re: Omeros Corporation – Registration Statement on Form S-3 for Shares of Common Stock

Dear Sirs:

This agreement is being delivered to you in connection with the proposed Underwriting Agreement (the “Underwriting Agreement”) between Omeros Corporation, a Washington corporation (the “Company”), and Cowen and Company, LLC (“Cowen”), as a representative of a group of underwriters (collectively, the “Underwriters”), to be named therein, relating to the proposed public offering of shares of the common stock, par value $0.01 per share (the “Common Stock”) of the Company.

In order to induce you and the other Underwriters to enter into the Underwriting Agreement, and in light of the benefits that the offering of Common Stock will confer upon the undersigned in its capacity as a securityholder and/or an officer, director or employee of the Company, and for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with each Underwriter that, during the period beginning on and including the date of the Underwriting Agreement through and including the date that is the 90^th day after the date of the Underwriting Agreement (the “Lock-Up Period”), the undersigned will not, without the prior written consent of Cowen, 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 (including, without limitation, Common Stock which may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations promulgated by the Securities and Exchange Commission, as the same may be amended or supplemented from time to time) or securities convertible into or exercisable or exchangeable in Common Stock, (ii) enter into any swap, hedge or similar agreement or arrangement that transfers in whole or in part, the economic risk of ownership of the Common Stock or securities convertible into or exercisable or exchangeable in Common Stock, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition, or (iii) engage in any short selling of Common Stock.

Only to the extent that the rules of the Financial Industry Regulatory Authority, Inc. relating to such extensions (or any successor rules thereto) remain in effect, if (i) the Company issues an earnings release or material news or a material event relating to the Company occurs during the last 17 days of the Lock-Up Period, or (ii) prior to the expiration of the Lock-Up Period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the Lock-Up Period, the Lock-Up Period shall be extended and the restrictions imposed by this agreement shall continue to apply until the expiration of the 18-day period beginning on the date of the issuance of the earnings release, the occurrence of the material news or material event or the announcement, as applicable, unless Cowen waives, in writing, such extension. Notwithstanding the foregoing, the Lock-Up Period shall not be extended pursuant to the preceding sentence if (i) the shares of Common Stock are “actively traded securities” as defined in Regulation M of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), (ii) the Company meets the applicable requirements of paragraph (a)(1) of Rule 139 under the Securities Act of 1933, as amended (the “Securities Act”), in the manner contemplated by FINRA Rule 2711(f)(4) and (iii) the provisions of FINRA Conduct Rule 2711(f)(4) are not applicable to any research reports relating to the Company published or distributed by any of the Underwriters during the 15 days before or after the last day of the Lock-Up Period (before giving effect to such extension).

The restrictions set forth in the immediately preceding two paragraphs shall not apply to:

(1) if the undersigned is a natural person, any transfers made by the undersigned (a) as a bona fide gift to any member of the immediate family (as defined below) of the undersigned or to a trust the beneficiaries of which are exclusively the undersigned or members of the undersigned’s immediate family, (b) by will or intestate succession upon the death of the undersigned or (c) as a bona fide gift to a charity, non-profit organization or educational institution,

(2) if the undersigned is a corporation, partnership, limited liability company or other business entity, any transfers to any shareholder, partner or member of, or owner of a similar equity interest in, the undersigned, as the case may be, if, in any such case, such transfer is not for value,

(3) if the undersigned is a corporation, partnership, limited liability company or other business entity, any transfer made by the undersigned (a) in connection with the sale or other bona fide transfer in a single transaction of all or substantially all of the undersigned’s capital stock, partnership interests, membership interests or other similar equity interests, as the case may be, or all or substantially all of the undersigned’s assets, in any such case not undertaken for the purpose of avoiding the restrictions imposed by this agreement or (b) to another corporation, partnership, limited liability company or other business entity so long as the transferee is an affiliate (as defined below) of the undersigned and such transfer is not for value; and

(4) the transfer or sale of any shares of Common Stock or other securities pursuant to any contract, instruction or plan meeting the requirements of Rule 10b5-1 under the Exchange Act, that has been entered into by the undersigned (or a member of the undersigned’s immediate family) prior to the date of the Underwriting Agreement;

provided, however, that in the case of any transfer described in clause (1)(a), 1(b), (2) or (3) above, it shall be a condition to the transfer that (A) the transferee executes and delivers to Cowen, acting on behalf of the Underwriters, not later than one business day prior to such transfer, a written agreement, in substantially the form of this agreement (it being understood that any references to “immediate family” in the agreement executed by such transferee shall expressly refer only to the immediate family of the undersigned and not to the immediate family of the transferee) and otherwise satisfactory in form and substance to Cowen, and (B) if the undersigned is required to file a report under Section 16(a) of the Exchange Act reporting a reduction in beneficial ownership of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock during the Lock-Up Period (as the same may be extended as described above), the undersigned shall include a statement in such report to the effect that, in the case of any transfer pursuant to clause (1) above, such transfer is being made as a gift or by will or intestate succession or, in the case of any transfer pursuant to clause (2) above, such transfer is being made to a shareholder, partner or member of, or owner of a similar equity interest in, the undersigned and is not a transfer for value or, in the case of any transfer pursuant to clause (3) above, such transfer is being made either (a) in connection with the sale or other bona fide transfer in a single transaction of all or substantially all of the undersigned’s capital stock, partnership interests, membership interests or other similar equity interests, as the case may be, or all or substantially all of the undersigned’s assets or (b) to another corporation, partnership, limited liability company or other business entity that is an affiliate of the undersigned and such transfer is not for value.

Notwithstanding the restrictions described herein, the undersigned may at any time after the date hereof (A) exercise any options or warrants to purchase shares of Common Stock (including any cashless exercise to the extent permitted by the instruments representing such options or warrants); provided that in any such case the shares of Common Stock issued upon exercise shall remain subject to the provisions of this agreement and, if the undersigned is required to file a report under Section 16(a) of the Exchange Act during the Lock-Up Period (as the same may be extended as described above) in connection with such exercise, the undersigned shall include a statement in such report to the effect that such disposition was pursuant to cashless exercise of an option or warrant, as applicable, or (B) enter into a trading plan (a “New Plan”) meeting the requirements of Rule 10b5-1 under the Exchange Act, relating to the sale of shares of Common Stock or other securities, if then permitted by the Company and applicable law; provided, that the shares of Common Stock or other securities subject to such New Plan shall not be sold during the Lock-Up Period. For purposes of this paragraph, “immediate family” shall mean a spouse, domestic partner, child, grandchild or other lineal descendant (including by adoption), father, mother, brother or sister of the undersigned; and “affiliate” shall have the meaning set forth in Rule 405 under the Securities Act.

The undersigned further agrees that (i) it will not, during the Lock-Up Period (as the same may be extended as described above), make any demand or request for or exercise any right with respect to the registration under the Securities Act, of any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, and (ii) the Company may, with respect to any Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock owned or held (of record or beneficially) by the undersigned, cause the transfer agent or other registrar to enter stop transfer instructions and implement stop transfer procedures with respect to such securities during the Lock-Up Period (as the same may be extended as described above). In addition, the undersigned hereby waives, from the date hereof until the expiration of the Lock-Up Period and any extension of such period pursuant to the terms hereof, any and all rights, if any, to request or demand registration pursuant to the Securities Act, of any shares of Common Stock that are registered in the name of the undersigned.

It is understood that, if (i) the Company notifies Cowen in writing that it does not intend to proceed with the offering of Common Stock contemplated by the Underwriting Agreement; (ii) if the Underwriting Agreement relating to the offering of Common Stock is not executed on or before April 30, 2014; or (iii) the Underwriting Agreement (other than the provisions thereof that survive termination) shall terminate or be terminated for any reason prior to payment for and delivery of the shares of Common Stock to be sold thereunder, this agreement shall immediately terminate and the undersigned shall automatically be released from all of his, her or its obligations under this agreement.

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this agreement and that this agreement has been duly authorized (if the undersigned is not a natural person), executed and delivered by the undersigned and is a valid and binding agreement of the undersigned. This agreement and all authority herein conferred are irrevocable and shall survive the death or incapacity of the undersigned (if a natural person) and shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

This agreement shall be governed by and construed in accordance with the law of the State of New York, without regard to the conflict of laws principles thereof.

The undersigned acknowledges and agrees that whether or not any public offering of Common Stock actually occurs depends on a number of factors, including market conditions.


		Very truly yours,


		(Name of Shareholder - Please Print)


		(Signature)


		(Name of Signatory if Shareholder is an entity - Please Print)


		(Title of Signatory if Shareholder is an entity - Please Print)

		Address:

Exhibit II

Opinion of Covington & Burling LLP

1. To our knowledge, the offering or sale of the Shares contemplated by the Underwriting Agreement does not give rise to any rights that entitle or will entitle any person to acquire from the Company any other shares of capital stock of the Company upon the issuance of the Shares by the Company, pursuant to any material agreement or instrument listed on Schedule A attached hereto.

2. The issuance of the Shares and the execution and delivery of the Underwriting Agreement by the Company and the consummation by the Company of the transactions contemplated thereby in accordance with the terms thereof do not (i) breach or conflict with the provisions of, or cause a default under, any material agreement or instrument listed on Schedule A attached hereto, or (ii) violate or conflict with any New York or federal statute, law, rule or regulation or any judgment or decree, known to us to which the Company or any of its properties or assets is subject.

3. No consent, approval, authorization or other action by or filing with any governmental agency or instrumentality of the United States of America is required on the part of the Company for the issuance of the Shares or the execution and delivery of the Underwriting Agreement or the consummation of the transactions contemplated thereby in accordance with the terms thereof, except those required under federal and state securities laws.

4. The statements in the Prospectus under the caption “Material U.S. Federal Income Tax Consequences to Non-U.S. Holders” constitute, in all material respects, a fair and accurate summary of the United States federal income tax consequences of the ownership and disposition of the Shares by a non-U.S. holder.

5. The Registration Statement has become effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement has been issued under the Securities Act and no proceedings for that purpose have been instituted or are pending or threatened by the Commission. The Pricing Prospectus and the Prospectus have each been filed in the manner and within the time period required by Rule 424(b) under the Securities Act.

6. The Registration Statement, on the date of its effectiveness, and the Prospectus, as of its date (excluding the financial statements, including the notes thereto, the financial schedules and the other financial and statistical data included therein, as to which we express no opinion), complied as to form in all material respects with the requirements of the Securities Act and the rules and regulations of the Commission thereunder.

7. To our knowledge, except as have been duly waived, no person has the right as a result of the filing of the Registration Statement or the offering contemplated by the Underwriting Agreement, pursuant to the terms of any contract, agreement, or other instrument described on Schedule A attached hereto, to cause the Company to register under the Securities Act any shares of Common Stock or shares of any other capital stock in the Company or to include any such shares or other securities in the Registration Statement or the offering contemplated by the Underwriting Agreement.

8. The Company is not, and after giving effect to the offering and sale of the Shares and the application of the proceeds thereof, will not be an “investment company,” as such term is defined in the Investment Company Act of 1940, as amended.

In addition, as special counsel to the Company, we reviewed the Registration Statement, the Disclosure Package and the Prospectus and participated in discussions with your representatives and those of the Company, your counsel and the Company’s accountants. On the basis of the information which was reviewed by us in the course of the performance of the services referred to above, considered in the light of our understanding of the applicable law and the experience we have gained through our practice under the federal securities laws, we confirm to you that nothing which came to our attention in the course of such review has caused us to believe that (a) the Registration Statement on the date of the effectiveness of the Registration Statement 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, (b) the Disclosure Package as of [TIME] A.M. on March [ • ], 2014 contained an untrue

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

Exhibit III

Opinion of General Counsel to the Company

(i) The statements in the Registration Statement, the General Disclosure Package and the Prospectus relating to the Intellectual Property Rights and Intellectual Property Assets (as defined in the Underwriting Agreement) (the “Intellectual Property Information”) are accurate and complete in all material respects and present fairly the information purported to be shown.

(ii) To my knowledge and except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, there is no material action, suit, claim or proceeding relating to the patents, patent applications, patent rights or licenses, trademarks or trademark rights, copyrights, collaborative research, licenses or royalty arrangements or agreements or trade secrets, know-how or proprietary techniques, indulging processes and substances, owned by or affecting the business or operations of the Company that are pending or threatened against the Company or any of its officers or directors. I am not aware of any pending or threatened claim, suit, judicial or governmental proceedings relating to the patents or the patent applications or the subject matter therein.

(iii) The Company and/or the Company’s licensors are listed in the records of the United States Patent and Trademark Office (USPTO) as the holder of record of the patent and patent applications listed onSchedule I (the “U.S. Patents” and the “U.S. Patent Applications”, respectively), except for those U.S. Patent Applications listed onSchedule I that are identified as having been recently filed for which assignments for the benefit of the Company or its licensors are in process. To my knowledge, and except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, there are no claims of third parties to any ownership interest or lien with respect to any of the U.S. Patents or U.S. Patent Applications. I am not aware of any material defect in form in the preparation or filing of the U.S. Patent Applications on behalf of the Company. Nothing has come to my attention that leads me to believe that any of the U.S. Patent Applications will not, for lack of novelty or due to a statutory bar, eventuate in issued patents, or that any of the patents issued in respect of any such U.S. Patent Applications will not be valid for lack of novelty or due to a statutory bar or will not afford the Company the patent protection described by the claims that may ultimately issue therein. I reasonably believe that each of the U.S. Patents and U.S. Patent Applications discloses patentable subject matter. To the best of my knowledge, all art references material to patentability as defined in 37 CFR § 1.56 known to the Company or me during the prosecution of the U.S. Patents and U.S. Patent Applications were disclosed to the USPTO (or will be disclosed in those U.S. Patent Applications just recently filed within the statutory period available for such disclosure) and, to the best of my knowledge, neither I nor the Company made any material misrepresentation to, or concealed any material fact from, the USPTO during such prosecution. To my knowledge, the U.S. Patent Applications have been reasonably prepared and filed, and are being reasonably pursued by the Company, and except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, the inventions described in the U.S. Patents and U.S. Patent Applications are owned by, assigned, or subject to an enforceable agreement to assign to the Company and/or its licensors. To my knowledge, the Company and/or the Company’s licensors own as their respective sole or joint property the U.S. Patents and pending U.S. Patent Applications.

(iv) To my knowledge and in reliance on communications from relevant foreign patent counsel, the Company and/or its licensors are listed in the records of the appropriate foreign offices as the sole and/or joint holders of record of the foreign patents and foreign patent applications listed onSchedule I (the “Foreign Patents” and “Foreign Patent Applications”, respectively). I do not know of any claims of third parties to any ownership interest or lien with respect to the Foreign Patents or Foreign Patent Applications. To my knowledge and in reliance on communications from relevant foreign patent counsel, I am not aware of any material defect of form in the preparation or filing of the Foreign Patent Applications on behalf of the Company. To my knowledge, the Foreign Patent Applications are reasonably being pursued by the Company. To my knowledge, the Company and/or its licensors own as their sole or joint property the Foreign Patents and pending Foreign Patent Applications.

(v) I know of no reason why the U.S. Patents are not valid and enforceable as issued, have not been notified of the invalidity of the Foreign Patents and know of no reason that would result in a third party other than the Company’s licensors having any rights in any patents issuing from such patent applications. I am not aware of any facts that would clearly and convincingly establish an irrebuttable basis for a finding of unenforceability or invalidity of any of the U.S. Patents or Foreign Patents of the Company except as described in the Registration Statement, the General Disclosure Package and the Prospectus.

(vi) The Company is the exclusive licensee of the U.S. Patents, Foreign Patents, U.S. Patent Applications and Foreign Patent Applications listed onSchedule I as having been in-licensed, except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus. All licenses of the Company to patents and patent applications, whether United States or foreign, are duly executed, validly binding and enforceable under U.S. law in accordance with their terms and, to my knowledge, the Company is not in default (declared or undeclared) of any material provision of such licenses.

(vii) I know of no contracts or other documents relating to the Company’s owned or licensed patents or patent applications, or to inventions, industrial property, trademarks (both registered and unregistered), trade names, service marks (both registered and unregistered), service names, copyrights, trade secrets, research results, know-how or other proprietary rights and information or materials of the Company that relate to the Company’s owned or licensed patents or patent applications, that is, based on the description of the Company’s business described in the Registration Statement, the General Disclosure Package or the Prospectus, of a character required to be described in the Registration Statement, the General Disclosure Package or the Prospectus that have not been so described.

(viii) To my knowledge and limited to the laws of the United States and the State of Washington, except as described in the Registration Statement, the General Disclosure Package or the Prospectus, and except for third party rights already licensed or otherwise obtained by the Company, and except for any non-target specific patents related to the engineering, expression and purification of biologics that may need to be licensed and are generally available for license, as is standard in the industry for the manufacture of biologics, in connection with the potential manufacture of commercial biologics for the Company’s MASP-2 and plasmin programs, and without having performed freedom to operate searches of any third party patents or other third party intellectual property rights, I am not aware of any third party patents or other third party intellectual property rights that, in my opinion, are valid and enforceable and are necessary for the manufacture, use, sale or offer for sale of the Company’s current configuration of its product candidates based on business now conducted or specifically proposed to be conducted as described in the Registration Statement, the General Disclosure Package or the Prospectus. To my knowledge and limited to the laws of the United States, except as described in the in the Registration Statement, the General Disclosure Package or the Prospectus, and without having performed any searches for and analyses of potentially infringing activities by any third party, I am not aware of facts that in the aggregate have led me to conclude that any third party is infringing or misappropriating the Company’s patents and patent applications.

(ix) Except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, I have no knowledge that (i) the Company is infringing or otherwise violating, and, upon the commercialization and sale of the product candidates of the Company described in the Registration Statement, the General Disclosure Package or the Prospectus would infringe or otherwise violate, any valid and enforceable patents, trade secrets, trademarks, service marks, copyrights or other proprietary information or materials of others, and I am unaware of any facts that would form a reasonable basis for a claim of any such infringement, that could reasonably be expected to result in a Material Adverse Effect and (ii) there are any infringements by others of any of the patents of the Company, and I am not aware of any facts that would form a reasonable basis for a claim of any such infringement.

(x) Except as disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, I have no knowledge that the Company lacks or will be unable to obtain any rights or licenses to use patents that are, or would be, reasonably necessary to conduct the business now conducted or proposed to be conducted by the Company as described in the Registration Statement, the General Disclosure Package or the Prospectus.

(xi) Except as disclosed in the General Disclosure Package and the Prospectus, there is not pending or, to my knowledge, threatened, any action, suit, proceeding, inquiry or investigation, to which the Company or any of its subsidiaries is a party, or to which the property of the Company or any of its subsidiaries is subject, before or brought by any court or governmental agency or body, domestic or foreign, which could reasonably be expected to result in a Material Adverse Effect, or which could reasonably be expected to materially and adversely affect the consummation of the transactions contemplated in the Underwriting Agreement or the performance by the Company of its obligations thereunder.

(xii) There are no legal or governmental proceedings pending or, to my knowledge, threatened in writing against the Company, or to which the Company or any of its property is subject, that are required to be described in the Registration Statement, the Disclosure Package and the Prospectus that are not described as required. For purposes of the opinions set forth in this paragraph, I have not searched any court or other docket or conducted any similar searches.

(xiii) The statements under the heading “Part II, Item 1. Legal Proceedings” in the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2013, as incorporated by reference into the Registration Statement and the Prospectus and as updated in Risk Factors set forth in the Prospectus, to the extent that such statements constitute matters of law or regulation, or legal conclusions, have been reviewed by me and are accurate and complete in all material respects.

Nothing has come to my attention that leads me to believe that (i) the Intellectual Property Information included in the Registration Statement, at the time it became effective under the Act (including the information incorporated by reference therein or deemed to be a part of the Registration Statement at the time it became effective pursuant to Rules 430A, 430B or 430C under the Act) and as of the date hereof and at each Closing Date, as the case may be, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) any statement or information corresponding to the Intellectual Property Information contained in the General Disclosure Package, as of the Applicable Time, 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 and (iii) the Intellectual Property Information included in the Prospectus, or any supplement thereto, on the date it was filed pursuant to the Rules and Regulations and as of the date hereof contained or contains an untrue statement of a material fact or omitted or omits 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 that I express no view as to financial statements and schedules and other financial data therein or any statements or information therein other than the Intellectual Property Information).

Exhibit IV

Opinion of Associate General Counsel to the Company

1. The Company has been duly incorporated and is validly existing as a corporation under the laws of the State of Washington and has the corporate power and authority to execute and deliver the Underwriting Agreement and to issue, sell and deliver the Shares to the Underwriters as provided therein, and to own and lease its properties and conduct its business as described in the Prospectus.

2. The Subsidiary has been duly incorporated, and is validly existing and in good standing under the laws of the State of Delaware and has the corporate power and authority to own and lease its properties and conduct its business as described in the Prospectus. The Subsidiary is duly qualified as a foreign corporation authorized to transact business in the State of Washington.

3. All of the issued and outstanding capital stock of the Subsidiary has been duly authorized and validly issued and is fully paid and nonassessable; the capital stock of the Subsidiary is owned free from any liens or encumbrances.

4. The Company has duly authorized, executed and delivered the Underwriting Agreement.

5. The authorized capital stock of the Company conforms in all material respects as to legal matters to the description thereof contained or incorporated by reference in the Prospectus under the caption “Description of Our Capital Stock.”

6. The authorized capital stock of the Company is as set forth under the caption “Description of Our Capital Stock” in the Prospectus. All of the issued and outstanding shares of Common Stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable. None of the outstanding shares of Common Stock were issued in violation of the preemptive or other similar rights of any shareholder of the Company.

7. The Shares have been duly authorized by the Company and, when issued and delivered by the Company pursuant to the Underwriting Agreement against payment of the consideration set forth in the Underwriting Agreement, will be validly issued and fully paid and non-assessable. The offer and sale of the Shares contemplated by the Underwriting Agreement does not give rise to any rights under the Articles of Incorporation, the Bylaws or the laws of the State of Washington, that entitle or will entitle any person to acquire from the Company any other shares of capital stock of the Company upon the issuance of the Shares by the Company.

8. The statements under the heading “Description of Our Capital Stock” in the Registration Statement, to the extent that such statements constitute matters of law or regulation, summaries of the Company’s Articles of Incorporation or Bylaws or legal conclusions, have been reviewed by me and are accurate and complete in all material respects.

9. To my knowledge, there are no agreements, contracts, indentures, leases or other instruments that are required to be described in the Registration Statement, the Disclosure Package and the Prospectus or to be filed as an exhibit to the Registration Statement or a document incorporated by reference therein that are not described or filed as required, as the case may be.

10. The issuance of the Shares and the execution and delivery of the Underwriting Agreement by the Company and the consummation by the Company of the transactions contemplated thereby in accordance with the terms thereof do not (i) violate or conflict with the provisions of the Company’s Articles of Incorporation or Bylaws or the provisions of the Subsidiary’s Certificate of Incorporation or Bylaws or (ii) violate or conflict with any (a) State of Washington statute, law, rule or regulation known to me to be customarily applicable to transactions of the type contemplated by the Underwriting Agreement, or (b) judgment, or decree, known to me to which the Company or any of its properties or assets is subject.

Exhibit V

Company Regulatory Affairs Certificate

This certification is being furnished pursuant to Section 6(f) of the Underwriting Agreement dated March , 2014 between Omeros Corporation, a Washington corporation (the “Company”) and Cowen and Company, LLC, as representative (the “Representative”) of the several Underwriters named inSchedule A thereto, in connection with the Underwriters’ purchase of [ ] shares of the Company’s Common Stock (the “Underwriting Agreement”). Capitalized terms used herein but not defined herein shall have the meanings ascribed to them in the Underwriting Agreement.

We, the undersigned, are the Chairman and Chief Executive Officer and the Vice President, Regulatory Affairs and Quality Systems, of the Company. In our respective capacities as Chairman and Chief Executive Officer and Vice President, Regulatory Affairs and Quality Systems, of the Company, we have reviewed at the Representative’s request the statements in the Registration Statement, the General Disclosure Package and the Prospectus, including, without limitation, in the documents incorporated by reference therein, under the headings “Business” and “Risk Factors” (collectively, the “Regulatory Disclosure”).

We have examined originals, or copies that are identified as being true copies of originals, of submissions made by the Company and any of its subsidiaries to the U.S. Food and Drug Administration (the “FDA”) and the European Medicines Agency or any of its member states (collectively the “EMA”) pertaining to the Company’s or any of its subsidiaries’ product candidates identified in the Registration Statement, the General Disclosure Package and the Prospectus and related correspondence between the FDA and the Company, the EMA and the Company, and representative files pertaining to such product candidates.

Based on our review of the above referenced documents, we hereby confirm that:

(i) The statements in the Regulatory Disclosure, insofar as such statements (a) purport to describe or summarize applicable provisions of the Federal Food, Drug, and Cosmetic Act, the regulations promulgated thereunder, and the applicable requirements of the EMA, or (b) describe the Company’s product candidates, are accurate and complete in all material respects and fairly present the information set forth therein;

(ii) the Company and each of its subsidiaries have obtained such licenses, permits, approvals, and authorizations required by the FDA and the EMA that are necessary for the conduct of the business of the Company and any of its subsidiaries as they are currently conducted and described in the Registration Statement, the General Disclosure Package and the Prospectus and, to our knowledge, such authorizations are in effect.

(iii) We are not aware of any lawsuit or regulatory proceeding, pending or threatened, brought by or before the FDA or the EMA in which the Company or any of its subsidiaries is or would be the defendant or respondent, nor are we aware of any adverse judgment, decree, or order currently in effect that has been issued by the FDA or the EMA against the Company or any of its subsidiaries.

(iv) With regard to regulatory matters, we (a) have no reason to believe that the Registration Statement and the Prospectus included therein as of the time the Registration Statement became effective, the date hereof and each Closing Date contained any 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 and (b) have no reason to believe that the Prospectus as of its date and as of the date hereof contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading.

Omeros (OMER) 8-KOmeros Prices $35.0 Million Public Offering of Common Stock