Exhibit 1.1

8,333,334 Shares

KEMPHARM, INC.

Common Stock

UNDERWRITING AGREEMENT

October 5, 2018

pursuant to Rule 424(b) of the Rules and Regulations in accordance with Section 4(a) hereof and (v) 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, to the Company’s Knowledge, threatened by the Commission (any preliminary prospectus included in the Initial Registration Statement or filed with the Commission pursuant to Rule 424(a) of the Rules and Regulations 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 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 and 430C under the Securities Act to be part of the Initial Registration Statement at the time it 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) under the Rules and Regulations, is hereinafter called the “ Prospectus .”

Any reference herein to the Registration Statement, Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein. 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 incorporated by reference in such Preliminary Prospectus or Prospectus, as the case may be. Any reference to (i) the Registration Statement shall be deemed to refer to and include 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 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 Statement shall be deemed to refer to and include 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 on Schedule B hereto, all considered together (collectively, the “ General Disclosure Package ”), (ii) any individual Limited Use Free Writing Prospectus (as defined below), nor (iii) the bona fide electronic road show (as defined in Rule 433(h)(5) of the Rules and Regulations that has been made available without restriction to any person), if any, 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

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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 (as defined below) or any Issuer Free Writing Prospectus (as defined below), 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 Underwriters’ Information (as defined in Section 17). As used in this paragraph (b) and elsewhere in this Agreement:

“ Applicable Time ” means 8:05 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 Base Prospectus, as amended and supplemented immediately prior to the Applicable Time, including any document incorporated by reference therein and any prospectus supplement with respect to the offer of the Stock 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 on Schedule 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, 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 Underwriters’ Information (as defined in Section 17).

(d) At the respective times the Registration Statements and any amendments thereto became or become effective 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

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amendment or supplement thereto was issued and at the 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 the Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriters’ 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(h), 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 that has not been 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; provided , however , that the foregoing representations and warranties in this paragraph (e) shall not apply to information contained in or omitted from an Issuer Free Writing 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 Underwriters’ Information (as defined in Section 17).

(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 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 the 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 the 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 and other materials, if any, permitted under the Securities Act and consistent with Section 4(d) below. The Company will file with the Commission all Issuer Free Writing Prospectuses required to be filed in the time and manner required under Rules 163(b)(2) and 433(d) of the Rules and Regulations.

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(h) From the time of the initial filing of the Registration Statement with the Commission through the date hereof, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the Securities Act (an “ Emerging Growth Company ”).

(i) The Company currently is not an “ineligible issuer,” as defined in Rule 405 of the Rules and Regulations.

(j) The Company has not engaged in any Testing-the-Waters Communications and has not authorized anyone to engage in Testing-the-Waters Communications. The Company has not distributed any written Testing-the-Waters Communications. “ Testing-the Waters Communications ” means any oral or written communication with potential investors undertaken in reliance on Section 5(d) of the Securities Act.

(k) The Company has been duly organized and is validly existing as a corporation in good standing (or the foreign equivalent thereof) under the laws of the State of Delaware. The Company is duly qualified to do business and is in good standing as a foreign corporation or in each jurisdiction in which its respective ownership or lease of property or the conduct of its business requires such qualification and has all power and authority (corporate or other) necessary to own or hold its properties and to conduct the business in which it is 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, liabilities, earnings, business or prospects of the Company, 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 has no subsidiaries.

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

(m) 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 will conform to the description thereof contained in the General Disclosure Package and the Prospectus, and the issuance of the Stock is not subject to any preemptive or similar rights.

(n) 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 in all material respects to the description thereof contained in the General Disclosure Package and the Prospectus under the heading “Description of Capital Stock.” 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. As of June 30, 2018 there were no authorized or outstanding shares of capital stock, options, warrants, preemptive rights, rights of first refusal or other rights to purchase, or equity or

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debt securities convertible into or exchangeable or exercisable for, any capital stock of the Company other than those described above or accurately described in the General Disclosure Package. Since such date, the Company has not issued any securities other than (i) as described in the General Disclosure Package, (ii) Common Stock issued pursuant to the exercise of warrants or conversion of convertible securities or upon the exercise or vesting of stock options or other awards outstanding under the Company’s equity compensation or other plans, (iii) options, Common Stock or other securities granted or issued pursuant to the Company’s equity compensation or other plans, (iv) Common Stock issued pursuant to the terms of that certain Common Stock Sales Agreement by and between the Company and RBC Capital Markets, LLC, dated as of September 4, 2018 (the “ Sales Agreement ”), and (v) the Stock. The description of the Company’s stock option, stock bonus and other stock plans or arrangements, and the options or other rights granted thereunder, as described in the General Disclosure Package and the Prospectus, accurately and fairly present in all material respects the information required to be shown with respect to such plans, arrangements, options and rights.

(o) [Reserved.]

(p) 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 pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company is a party or by which the Company is bound or to which any of the property or assets of the Company is subject, (ii) result in any violation of the provisions of the certificate of incorporation or by-laws of the Company or (iii) result in any 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 properties or assets; except in the cases of clauses (i) and (iii), to the extent that any such conflict, breach, violation or default would not, individually or in the aggregate, have a Material Adverse Effect. 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.

(q) Except for the registration of the Stock under the Securities Act and applicable state securities laws, and such consents, approvals, authorizations, orders and registrations or qualifications that may be required by the Financial Industry Regulatory Authority (“ FINRA ”) and the Nasdaq Global Market (the “ Exchange ”) in connection with the purchase and distribution of the Stock by the Underwriters and the listing of the Stock on the Exchange, no consent, approval, authorization or order of, or filing, qualification or registration (each an “ Authorization ”) with, any court, governmental or

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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, issuance and sale of the Stock by the Company 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 stockholders) necessary for the Company to consummate the transactions contemplated by this Agreement have been obtained and are in effect.

(r) Each of RSM US LLP and Ernst & Young LLP, who have certified certain financial statements included, or incorporated by reference, in the Registration Statements, the General Disclosure Package and the Prospectus, is an independent registered public accounting firm with respect to the Company within the meaning of Article 2-01 of Regulation S-X and the Public Company Accounting Oversight Board (United States) (the “ PCAOB ”).

(s) 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 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; and provided that the unaudited interim financial statements, which are subject to normal year-end adjustments, may not contain certain footnotes, as permitted by the applicable rules of the Commission. 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 (if any) 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 in the Registration Statement, the Pricing Prospectus and the Prospectus and other financial information. All information contained or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus regarding “non-GAAP financial measures” (as defined in Regulation G) complies in all material respects with Regulation G and Item 10 of Regulation S-K, to the extent applicable.

(t) Other than as set forth or contemplated in the General Disclosure Package: (i) the Company has not sustained, since the date of the latest audited financial statements included or incorporated by reference in the General Disclosure Package, any material loss or material 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

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governmental action, order or decree; and (ii) since the date of the latest audited financial statements included in the General Disclosure Package, there has not been any material change in the capital stock (other than (1) Common Stock issued pursuant to the exercise of warrants or conversion of convertible securities or upon the exercise or vesting of stock options or other awards outstanding under the Company’s equity compensation or other plans, (2) options, Common Stock or other securities granted or issued pursuant to the Company’s equity compensation or other plans, (3) Common Stock issued pursuant to the Sales Agreement, (4) the issuance of the Stock and (5) stock repurchases required to be made by the Company pursuant to the terms of existing agreements) or long-term debt of the Company, or any material adverse changes, or any development involving a prospective material adverse change, in or affecting the business, assets, general affairs, management, financial position, prospects, stockholders’ equity or results of operations of the Company.

(u) Except as set forth in the General Disclosure Package, there is no legal or governmental proceeding to which the Company is a party or of which any property or assets of the Company 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, would have a Material Adverse Effect; and to the Company’s knowledge after reasonable investigation and due diligence inquiry (“ Knowledge ”), no such proceedings are threatened by governmental authorities or by others. 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, singularly or in the aggregate, have a Material Adverse Effect. All preclinical studies and clinical trials conducted by or on behalf of the Company 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 would not, singularly or in the aggregate, have a Material Adverse Effect.

(v) Except as described in the General Disclosure Package, the Company (i) is not in violation of its charter or by-laws, (ii) is not 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 (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) and (iii) is not 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 except, in the case of clauses (ii) and (iii) of this paragraph (v), for any violations or defaults which, singularly or in the aggregate, would not have a Material Adverse Effect.

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(w) The Company possesses all licenses, certificates, authorizations and permits issued by, and has 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 conduct of its business as described in the General Disclosure Package and the Prospectus (collectively, the “ Governmental Permits ”) except where any failures to possess or make the same, singularly or in the aggregate, would not have a Material Adverse Effect. The Company is in compliance with all such Governmental Permits, except where the failure to be in compliance would not, singularly or in the aggregate, have a Material Adverse Effect; all such Governmental Permits are valid and in full force and effect, except where the invalidity 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 material restriction or material condition. The Company has not received notification of any material 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 Knowledge that any such Governmental Permit will not be renewed. The studies, tests and preclinical studies 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; 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 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.

(x) The Company is not and, 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 not become an “investment company” or an entity “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(y) Neither the Company nor any of its officers, directors or, to the Company’s Knowledge, 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.

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(z) The Company owns or possesses 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 (“ Intellectual Property Rights ”) and (ii) inventions, software, works of authorships, trademarks, 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) (collectively, “ Intellectual Property Assets ”) necessary to conduct its business as currently conducted, and as currently proposed to be conducted and described in the General Disclosure Package and the Prospectus; provided that the foregoing representation is made only to the Company’s Knowledge as it concerns third-party rights and trademarks. The Company has not received any opinion from its legal counsel concluding that any activities of its business as currently conducted infringes, misappropriates, or otherwise violates, valid and enforceable Intellectual Property Rights of any other person, and has not received written notice of any challenge, which is to the Company’s Knowledge still pending, by any other person to the rights of the Company with respect to any Intellectual Property Rights or Intellectual Property Assets owned or used by the Company. To the Knowledge of the Company, the Company’s business as currently conducted does not infringe, misappropriate or otherwise violate any valid and enforceable Intellectual Property Rights of any other person. 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 Company and, to the Company’s Knowledge, the parties thereto in accordance to its terms, except (i) as limited by laws of general application relating to bankruptcy, insolvency and other relief of debtors, and (ii) as limited by rules of law governing specific performance, injunctive relief or other equitable remedies and by general principals of equity. The Company has complied in all material respects with, and is not in breach in any material respect nor has received any asserted or threatened claim of breach of any intellectual property license, and the Company has no Knowledge of any breach or anticipated breach by any other person to any intellectual property license to which the Company is a party. Except as described in the General Disclosure Package, 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. The Company has taken reasonable steps to protect, maintain and safeguard its Intellectual Property Rights, including the execution of appropriate nondisclosure and confidentiality agreements. 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 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 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

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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, modification, or other misuse. The Company has taken commercially reasonable measures 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 that are material to the Company’s business. All founders and key employees have signed confidentiality and invention assignment agreements with the Company.

(aa) The Company has valid title to, or has valid rights to lease or otherwise use, all items of real or personal property (provided, that for the sake of clarity, rights to Intellectual Property Assets are addressed exclusively in Section 2(z) above) which are material to the business of the Company, in each case free and clear of all liens, encumbrances, security interests, claims and defects other than those described in the General Disclosure Package and the Prospectus and those 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; and all of the leases and subleases material to the business of the Company and under which the Company holds properties described in the General Disclosure Package and the Prospectus, are in full force and effect, and the Company does not have any notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company under any of the leases or subleases mentioned above, or affecting or questioning the rights of the Company to the continued possession of the leased or subleased premises under any such lease or sublease.

(bb) There is (i) no significant unfair labor practice complaint pending against the Company, nor to the Knowledge of the Company, threatened against it, before the National Labor Relations Board, any state or local labor relation board or any foreign labor relations board, and no significant grievance or significant arbitration proceeding arising out of or under any collective bargaining agreement is so pending against the Company, or, to the Knowledge of the Company, threatened against it and (ii) no labor disturbance by the employees of the Company 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 principal suppliers, manufacturers, customers or contractors, that would 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 plans to terminate employment with the Company.

(cc) 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 would reasonably be expected to occur with respect to any employee benefit plan of the Company which would, singularly or in the aggregate, have a Material Adverse Effect. Each employee benefit plan of the Company is in compliance in all material respects with applicable law, including ERISA and the Code. The Company has not incurred and

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would not reasonably be expected to incur material 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 would have any liability that is intended to be qualified under Section 401(a) of the Code is so qualified, and to the Company’s Knowledge, nothing has occurred, whether by action or by failure to act, which would, singularly or in the aggregate, cause the loss of such qualification.

(dd) The Company is in compliance in all material respects 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 ”). 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, to the Company’s Knowledge, any other entity for whose acts or omissions the Company is or may reasonably be expected to otherwise be liable) upon any of the property now or previously owned or leased by the Company, 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 liability other than any such violation or liability as would not have, singularly or in the aggregate, a Material Adverse Effect; 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 has Knowledge and which would have, singularly or in the aggregate, a Material Adverse Effect.

(ee) The Company (i) has timely filed all necessary federal, state, local and foreign tax returns (or timely filed extensions with respect to such returns), and all such returns were true, complete and correct in all material respects, (ii) has 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 is obligated to withhold from amounts owing to employees, creditors and third parties (other than such amounts being disputed in good faith and by appropriate proceedings and for which appropriate reserves, if required, have been established), and (iii) does 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 (ee), that would not, singularly or in the aggregate, have a Material Adverse Effect. The Company has not engaged in any transaction which is a corporate tax shelter or which would 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 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, 2016 the Company has not incurred any liability for taxes other than in the ordinary course of business, except as described in the General Disclosure Package and the Prospectus.

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(ff) The Company carries, or is covered by, insurance in such amounts and covering such risks as generally deemed adequate and customary for the conduct of its business and the value of its properties and as is customary for companies engaged in similar businesses in similar industries. The Company does not have 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 are, to the Company’s Knowledge, in full force and effect and the Company is in material compliance with the terms of such policies. The Company has not received written notice from any insurer, agent of such insurer or the broker of the Company 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. The Company does not insure 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.

(gg) 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 any applicable 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 assurances that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (v) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement is accurate. 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, U.S. federal securities laws, or any financial reporting matter which, if determined adversely to the Company, would have a Material Adverse Effect.

(hh) A member of the Audit Committee has confirmed to the Chief Executive Officer or Chief Financial Officer of the Company that, except as set forth in the General Disclosure Package, the Audit Committee is not reviewing or investigating, and neither the Company’s independent auditors nor its internal auditors is recommending that the

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Audit Committee review or investigate, (i) adding to, deleting, changing the application of or changing the Company’s disclosure with respect to, any of the Company’s material accounting policies, (ii) any matter which could result in a restatement of the Company’s financial statements for any annual or interim period during the current or prior three fiscal years, or (iii) any Internal Control Event.

(ii) The Company has made and keeps books, records and accounts, which, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the Company in all material respects.

(jj) The Company maintains disclosure controls and procedures (as such is defined in Rule 13a-15(e) of the Exchange Act Rules) that comply with any applicable requirements of the Exchange Act; such disclosure controls and procedures have been reasonably 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 such disclosure controls and procedures will be effective immediately following the completion of the offering.

(kk) The minute books of the Company have been made available to the Underwriters and counsel for the Underwriters, and such books (i) contain an accurate summary of all meetings and actions of the board of directors (including each board committee) and stockholders of the Company since the time of its incorporation through the date of the latest meeting and action (other than such meetings that have occurred subsequent to July 10, 2018, a summary of the actions taken thereat has been communicated to the Underwriters and counsel for the Underwriters), and (ii) accurately in all material respects reflect all transactions referred to in such minutes.

(ll) [Reserved.]

(mm) No relationship, direct or indirect, exists between or among the Company on the one hand, and the directors, officers, stockholders (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.

(nn) No person or entity has the right to require registration of shares of Common Stock or other securities of the Company within 90 days of the date hereof because of the filing or effectiveness of the Registration Statements or otherwise, except as described in the General Disclosure Package or 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 under the Securities Act.

(oo) The Company does not 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.

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(pp) Except as described in the Initial Registration Statement, the General Disclosure Package or the Prospectus, the Company is not a party to any contract, agreement or understanding with any person (other than this Agreement and the Sales Agreement) 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.

(qq) [Reserved.]

(rr) [Reserved.]

(ss) 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, Company has not (i) incurred any material liability or obligation, direct or contingent, other than liabilities and obligations which were incurred in the ordinary course of business, (ii) entered into any material transaction other than in the ordinary course of business or (iii) declared or paid any dividend on its capital stock.

(tt) If applicable, all of the information provided to the Underwriters or to counsel for the Underwriters by the Company, its officers and directors and the holders of any securities (debt or equity) or options to acquire any securities of the Company in connection with letters, filings or other supplemental information provided to FINRA pursuant to FINRA Rule 5110 or 5121 is, to the Company’s Knowledge with respect to all other persons except for the Company, its officers and directors, true, correct and complete in all material respects as of the date hereof.

(uu) The Company is not a Passive Foreign Investment Company (“ PFIC ”) within the meaning of Section 1296 of the Code, and the Company is not likely to become a PFIC.

(vv) 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.

(ww) 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 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 Stock under the Exchange Act or delisting the Stock from the Exchange, nor has the Company received any notification that the Commission or FINRA is contemplating terminating such registration or listing.

(xx) 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 then in effect and is taking all reasonable steps to ensure that it will be in compliance in all material respects with other applicable provisions of the Sarbanes-Oxley Act not currently in effect upon the Company at all times after the effectiveness of such provisions.

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(yy) The Company is in compliance with all applicable corporate governance requirements set forth in the rules of the Exchange that are then in effect and is taking and will take all reasonable steps to ensure that it will be in compliance with other applicable corporate governance requirements set forth in the rules of the Exchange not currently in effect upon the Company at all times after the effectiveness of such requirements.

(zz) Neither the Company nor, to the Company’s Knowledge, any director, officer, employee, agent or affiliate of the Company, 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 or is in violation any provision of the Foreign Corrupt Practices Act of 1977, as amended and the rules and regulations thereunder, or any applicable law or regulation implementing the OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions, or committed an offence under the Bribery Act of 2010 of the United Kingdom, or any other applicable anti-bribery or anti-corruption law; (iv) made, offered, agreed, requested or taken an act in furtherance of any unlawful bribe or other unlawful benefit, including, without limitation, any rebate, payoff, influence payment, kickback or other unlawful or improper payment or benefit, or (v) made any other unlawful payment.

(aaa) 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 would 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 which have not been described as required.

(bbb) 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 to or for the benefit of any of the officers or directors of the Company 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 applicable U.S. law.

(ccc) 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 is consistent with the sources from which they are derived.

(ddd) The operations of the Company are and have been conducted at all times in compliance 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,

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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 with respect to the Money Laundering Laws is pending, or to the Company’s Knowledge, threatened. The Company acknowledges that, in accordance with the requirements of the USA Patriot Act, the Representative is required to obtain, verify and record information that identifies its clients, including the Company, which information may include the name and address of its clients, as well as other information that will allow the Representative to properly identify its clients.

(eee) The Company is not Insolvent (as defined below). For purposes of this Section 6(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 and is proposed to be conducted.

(fff) None of the Company nor, to the Company’s Knowledge, any director, officer, agent, employee, affiliate or other person associated with or acting on behalf of the Company, any director, officer, agent or employee or affiliate of the Company is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. government (including, without limitation, the Office of Foreign Assets Control (“ OFAC ”) of the U.S. Department of the Treasury or the U.S. Department of State and including, without limitation, the designation as a “specially designated national” or “blocked person”), the United Nations Security Council, the European Union, Her Majesty’s Treasury, or other relevant sanctions authority, nor is the Company’s business located, organized or resident in a country or territory that is subject or target of sanctions, including, without limitation, Cuba, Iran, North Korea, Sudan and Syria; and the Company will not directly or indirectly use the proceeds of the offering of the Stock, 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.

(ggg) There has been no material security breach or other material compromise of or relating to any of the Company’s information technology and computer systems, networks, hardware, software, data (including the data of their respective customers, employees, suppliers, vendors and any third party data maintained by or on behalf of them), equipment or technology (collectively, “ IT Systems and Data ”) and (i) the Company has not been notified of, and has no knowledge of any event or condition that would reasonably be expected to result in, any material security breach or other material compromise to its IT Systems and Data; (ii) the Company is presently in compliance with all applicable laws or statutes and all judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, internal policies and contractual obligations relating to the privacy and security of IT Systems and Data and to the protection of such IT Systems and Data from unauthorized use, access, misappropriation or modification, except as would not, in the case of this clause (ii), individually or in the aggregate, have a Material Adverse Effect; and (iii) the Company has implemented appropriate backup technology.

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(hhh) Neither the Company nor, to the Company’s Knowledge, any of its affiliates (within the meaning of FINRA Rule 5121(f)(1)) 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.

(iii) The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the 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.

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. P URCHASE , S ALE AND D ELIVERY OF O FFERED S ECURITIES . 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 in Schedule A hereto.

The purchase price per share to be paid by the Underwriters to the Company for the Stock will be $2.82 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, 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, all at the offices of Morgan, Lewis & Bockius LLP, 101 Park Avenue, New York, NY 10178. 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 October 10, 2018, or at such other time as the Representative and the Company mutually agree, in accordance with Rule 15c6-1 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 any over-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. Such shares of Optional Stock shall be purchased from the Company for the account of each Underwriter in the same proportion as the number of shares of Firm Stock set

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forth opposite such Underwriter’s name on Schedule A bears to the total number of shares of Firm Stock (subject to adjustment by the Representative to eliminate fractions). 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 prior to the exercise of such right upon written 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, 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, all at the offices of Morgan, Lewis & Bockius LLP, 101 Park Avenue, New York, NY 10178. 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. F URTHER A GREEMENTS O F T HE C OMPANY . 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 under 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 430B 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 and by Rule 430B of the Rules and Regulations; 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 (the “ Prospectus Delivery Period ”), to notify the Representative promptly of the Company’s intention to file or prepare any supplement or amendment to any of the

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Registration Statements or to the Prospectus and to make no amendment or supplement to any of 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, to advise the Representative, promptly after it receives notice thereof, of the time when any amendment to any of the Registration Statements 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 electronic 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 with respect to the offering of the Stock, 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; 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 will promptly notify the Representative if the Company ceases to be an Emerging Growth Company at any time prior to the later of (i) the completion of the distribution of the Firm Stock within the meaning of the Securities Act and (ii) completion of the Lock-Up Period (as defined below).

(c) [Reserved.]

(d) The Company represents and agrees that, unless it obtains the prior consent of the Representative, and each Underwriter 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 any Issuer Free Writing Prospectus included in Schedule 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.

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(e) [Reserved.]

(f) If at any time prior to the expiration of the Prospectus Delivery Period 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 its 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 satisfactory to the Representative which 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 upon request electronic copies 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 during the Prospectus Delivery Period, 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.

(g) 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 then prevailing, 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 then prevailing, be misleading or conflict with the Registration Statement then on file, or so that the General Disclosure Package will comply with law.

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(h) 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 prevailing at the subsequent time, 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 the Representative by or on behalf of any Underwriter specifically for inclusion therein, which information the parties hereto agree is limited to the Underwriters’ Information (as defined in Section 17).

(i) To the extent not available on the Commission’s Electronic Data Gathering, Analysis and Retrieval System (together with any successor system maintained by or on behalf of the Commission) (“ EDGAR ”), upon reasonable request of the Representative, 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.

(j) To the extent not available on EDGAR, upon reasonable request of the Representative, 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) and (iii) of this paragraph (j) 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, and, with respect to the documents referred to in clause (iv) of this paragraph (j), as soon as practicable thereafter), (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 (the delivery of the documents referred to in clauses (v) and (vi) of this paragraph (j) 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 (j) to be made not later than 10:00 A.M., New York City time, on the business day following the date of such document).

(k) To make generally available to its stockholders 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, to the extent applicable (which need not be audited), complying with Section 11(a) of the Securities Act and the Rules and Regulations (including, at the

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option of the Company, Rule 158), and to furnish to its stockholders as soon as practicable after the end of each fiscal year an annual report (including a balance sheet and statements of income, stockholders’ equity and cash flows of the Company certified by independent public accountants) and as soon as possible after each of the first three fiscal quarters of each fiscal year (beginning with the first fiscal quarter after the effective date of such Registration Statement), consolidated summary financial information of the Company for such quarter in reasonable detail; provided , that so long as the Company is subject to the reporting requirements of Section 13 or Section 15(d) of the Exchange Act and is timely filing reports with the Commission on EDGAR, the Company shall be deemed to be in compliance with the foregoing requirements to furnish such annual reports and quarterly financial information to its stockholders.

(l) 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 shall not be obligated to qualify as a foreign corporation in any jurisdiction in which it is not so qualified or to file a general consent to service of process in any jurisdiction or to become subject to taxation in any jurisdiction.

(m) Upon request, during the period of three (3) 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 stockholders, 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 its EDGAR system, it is not required to furnish such reports or statements to the Underwriters.

(n) 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 or announce the intention to otherwise dispose of, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, other than: (i) the Company’s sale of the Stock hereunder; (ii) the issuance of Common Stock or options to acquire Common Stock or other equity awards pursuant to the Company’s equity compensation or other plans as such plans are in existence on the date hereof and described in the Prospectus; (iii) the issuance of Common Stock pursuant to the valid exercises, vesting, exchanges or conversion of options, warrants, convertible or exchangeable securities or rights outstanding on the date hereof or otherwise issued pursuant to clause (iii) or (v); (iv) the issuance of Common Stock or securities convertible into or exercisable for shares of Common Stock in connection with any acquisition, collaboration, licensing or other strategic transactions or any debt financing transaction; or (v) the issuance of securities convertible into Common Stock pursuant to that certain Exchange Agreement with certain holders of the Company’s 5.50% Senior Convertible Notes due 2021, as described in the Prospectus under the heading “Summary – Recent Developments”; provided that, in the case of clause (iv), the sum of the aggregate number of shares of Common Stock or securities

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convertible into or exercisable for shares of Common Stock so issued shall not exceed 10% of the total outstanding shares of Common Stock immediately following the completion of the offering of the Stock and recipients of such shares of Common Stock or such securities convertible into or exercisable for shares of Common Stock agree in writing with the Representative not to, or are otherwise party to agreements with the Company pursuant to which they have agreed not to, directly or indirectly offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of or announce the intention to otherwise dispose of, such shares of Common Stock or such securities convertible into or exercisable or exchangeable for Common Stock during the Lock-Up Period without the prior written consent of the Representative (which consent may be withheld in the Representative’s sole discretion). The Company will cause each of the Company’s executive officers and directors, and each person or entity set forth on Schedule D hereto, to furnish to the Representative, prior to the Closing Date, a letter, substantially in the form of Exhibit I hereto. The Company also agrees that during such 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 (x) a registration statement on Form S-8 relating to employee stock purchase and employee benefit plans, or (y) a registration statement on Form S-3 pursuant to Section 2.1 of that certain Amended and Restated Investors’ Rights Agreement by and among the Company and the “Shareholders” party thereto, dated as of February 19, 2015.

(o) [Reserved.]

(p) 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.

(q) [Reserved.]

(r) Prior to the latest of the Closing Dates, not to issue any press release or other public communication directly or indirectly or hold any press conference with respect to the Company, its condition, financial or otherwise, or earnings, business affairs or business prospects (except for routine oral marketing communications in the ordinary course of business and consistent with the past practices of the Company and of which the Representative are notified), without the prior written consent of the Representative, unless in the judgment of the Company and its counsel, and after notification to the Representative, such press release or communication is required by law, rule or regulation or the rules of the Exchange.

(s) 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 in violation of Regulation M under the Exchange Act; 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 in violation of Regulation M under the Exchange Act.

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(t) Not to take any action prior to the latest of the Closing Dates which would require the Prospectus to be amended or supplemented pursuant to Section 4(f).

(u) To at all times comply in all material respects with all applicable provisions of the Sarbanes-Oxley Act in effect from time to time and to file with the Commission such information on Form 10-Q or Form 10-K as may be required by Rule 463 of the Rules and Regulations.

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

(w) 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.

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

(y) To use its commercially reasonable 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.

(z) 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. P AYMENT OF E XPENSES . 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 this Agreement and any closing documents by mail, telex or other means of communications; (d) the fees and expenses (including documented related fees and expenses of counsel for the Underwriters) (i) 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 and (ii) of qualifying the Stock under the securities laws of the several jurisdictions as provided in Section 4(l)) and of preparing, printing and distributing wrappers, Blue Sky Memoranda and Legal Investment Surveys, in an amount not to exceed in

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the aggregate pursuant to the foregoing clauses (i) and (ii) $15,000; (e) any applicable listing or other fees; (f) the cost of preparing and printing stock certificates; (g) all fees and expenses of the registrar and transfer agent of the Stock; (h) 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 and 50% of the cost of any aircraft chartered in connection with the road show with the prior consent of the Company, such consent not to be unreasonably withheld; and (i) all other costs and expenses of the Company 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, 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 and travel and lodging expenses of the representatives of the Underwriters and 50% of the cost of any aircraft chartered in connection with the road show.

6. C ONDITIONS OF U NDERWRITERS ’ O BLIGATIONS . The respective obligations of the several Underwriters hereunder are subject to the accuracy, when made and as of the Applicable Time and on each 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 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 unresolved 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

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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) Cooley LLP shall have furnished to the Representative such counsel’s written opinion and negative assurance letter, as counsel to the Company, addressed to the Underwriters and dated as of such Closing Date, in form and substance reasonably satisfactory to the Representative.

(e) McAndrews, Held & Malloy, Ltd. shall have furnished to the Representative such counsel’s written opinion, as intellectual property counsel to the Company, addressed to the Underwriters and dated as of such Closing Date, in form and substance reasonably satisfactory to the Representative.

(f) [Reserved.]

(g) The Representative shall have received from Morgan, Lewis & Bockius LLP, counsel for the Underwriters, such counsel’s written opinion or opinions, dated as of 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.

(h) At the time of the execution of this Agreement, the Representative shall have received from each of RSM US LLP and Ernst & Young LLP letters, 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 within the meaning of the Securities Act and the Rules and Regulations and 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.

(i) On the effective date of any post-effective amendment to any Registration Statement and on such Closing Date, the Representative shall have received letter (the “ bring-down letters ”) from each of RSM US LLP and Ernst & Young LLP addressed to the Underwriters and dated such Closing Date confirming, as of the date of the bring-down letters (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

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three (3) business days prior to the date of the bring-down letters), 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 letters delivered to the Representative concurrently with the execution of this Agreement pursuant to paragraph (h) of this Section 6.

(j) The Company shall have furnished to the Representative a certificate, dated such Closing Date, of its Chief Executive Officer and its Chief Financial Officer, in their capacities as such, stating that (i) such officers have carefully examined the Registration Statement, the General Disclosure Package, any Permitted Free Writing Prospectus and the Prospectus and, in their opinion on behalf of the Company, the Registration Statements and each amendment thereto, as of their respective effective dates 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 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 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 in the General Disclosure Package, any material adverse change in the financial position or results of operations of the Company, or any change or development that, singularly or in the aggregate, would involve a Material Adverse Effect, except as set forth in the Prospectus.

(k) Since the date of the latest audited financial statements included in the General Disclosure Package or incorporated into the General Disclosure Package as of the date hereof, (i) the Company shall not 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 (other than (1) Common Stock issued pursuant to the exercise of warrants or conversion of convertible securities or upon the exercise or vesting of stock options or other awards outstanding under the Company’s equity compensation or other plans, (2) options, Common Stock or other securities granted or issued pursuant to the Company’s equity compensation or other plans, (3) Common Stock issued pursuant to the Sales Agreement, (4) the issuance of the Stock and (5) stock repurchases required to be made by the Company pursuant to the terms of existing agreements) or long-term debt of the Company, or any change, or any development involving a prospective change, in or affecting the business, general affairs, management, financial position, stockholders’ equity or results of operations of the Company, in each case, otherwise than as set forth in

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the General Disclosure Package, the effect of which, in any such case described in clause (i) or (ii) of this paragraph (k), 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.

(l) No action shall have been taken and no law, statute, rule, regulation or order shall have been enacted, adopted or issued, in each case, by any governmental agency or body which would prevent the issuance or sale of the Stock or materially and adversely affect or potentially 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 potentially materially and adversely affect the business or operations of the Company.

(m) 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, the Exchange or the NYSE MKT LLC 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) 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.

(n) The Company shall have submitted a listing of additional shares notification form to the Exchange with respect to the Stock.

(o) The Representative shall have received on and as of such Closing Date satisfactory evidence of the good standing of the Company in the State of Delaware and its good standing as a foreign entity in the State of Iowa, the State of Florida and the Commonwealth of Virginia, in each case in writing or any standard form of telecommunication from the appropriate Governmental Authorities of such jurisdictions.

(p) The Representative shall have received the written agreements, substantially in the form of Exhibit I hereto, from each of the Company’s executive officers and directors, and each person or entity set forth on Schedule D hereto.

(q) 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.

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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.

(a) The Company agrees to indemnify, defend and hold harmless each Underwriter, its partners, employees, agents, members, directors and officers, any person who controls each Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act and any “affiliate” (within the meaning of Rule 405 under the Securities Act) of each Underwriter that has, or is alleged to have, participated in the distribution of Stock, and the successors and assigns of all the foregoing persons, from and against any loss, damage, expense, liability or claim (including, without limitation, the reasonable and documented cost of investigation and any reasonable and documented legal fees and other documented expenses reasonably incurred in connection with any suit, action, investigation or proceeding or any claim asserted), joint or several, which each Underwriter or any such person may incur under the Securities Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company) or arises out of or is based upon any omission or alleged omission to state a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information furnished in writing by or on behalf of the Representative to the Company expressly for use in, the Registration Statement or arises out of or is based upon any omission or alleged omission to state a material fact in the Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading or (ii) any untrue statement or alleged untrue statement of a material fact included in any Prospectus (the term Prospectus for the purpose of this Section 7 being deemed to include the Prospectus and any amendments or supplements to it), in any “issuer information” (as defined in Rule 433 under the Securities Act) of the Company, in any road show as defined under Rule 433(h) under the Securities Act (a “ road show ”) or in any free writing prospectus, or arises out of or is based upon any omission or alleged omission to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, except, with respect to such Prospectus, insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information furnished in writing by or on behalf of the Representative to the Company expressly for use in, such Prospectus or arises out of or is based upon any omission or alleged omission to state a material fact in such Prospectus in connection with such information, which material fact was not contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading.

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If any action, suit or proceeding (together, a “ Proceeding ”) is brought against any Underwriter or any such person in respect of which indemnity may be sought against the Company pursuant to the foregoing paragraph, such Underwriter or such person shall promptly notify the Company in writing of the institution of such Proceeding and the Company shall assume the defense of such Proceeding, including the employment of counsel reasonably satisfactory to such indemnified party and payment of all reasonably and documented fees and expenses; provided, however, that the omission to so notify the Company shall not relieve the Company from any liability which the Company may have to such Underwriters or any such person or otherwise except to the extent the Company was materially prejudiced by such omission, which shall include without limitation the loss of any material rights or defenses resulting therefrom. Such Underwriter or such person shall have the right to employ its or their own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of such Underwriter or of such person unless the employment of such counsel shall have been authorized in writing by the Company in connection with the defense of such Proceeding or the Company shall not have, within a reasonable period of time in light of the circumstances, employed counsel to have charge of the defense of such Proceeding or such indemnified party or parties shall have reasonably concluded that there may be defenses available to it or them which are different from, additional to or in conflict with those available to the Company (in which case the Company shall not have the right to direct the defense of such Proceeding on behalf of the indemnified party or parties), in any of which events such reasonable and documented fees and expenses shall be borne by the Company, and paid as incurred (it being understood, however, that the Company shall not be liable for the fees and expenses of more than one separate counsel (in addition to any local counsel) in any one Proceeding or series of related Proceedings in the same jurisdiction representing the indemnified parties who are parties to such Proceeding). The Company shall not be liable for any settlement of any Proceeding effected without its written consent but, if settled with the written consent of the Company, the Company agrees to indemnify and hold harmless the Underwriters and any such person from and against any loss or liability by reason of such settlement. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested the Company to reimburse the indemnified party for reasonable and documented fees and expenses of counsel as contemplated by the second sentence of this paragraph, then the Company agrees that it shall be liable for any settlement of any Proceeding effected without its written consent if (i) such settlement is entered into more than 60 business days after receipt by the Company of the aforesaid request, (ii) the Company shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement and (iii) such indemnified party shall have given the Company at least 30 days’ prior notice of its intention to settle. The Company shall not, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened Proceeding in respect of which any indemnified party is or may be a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such Proceeding and does not include any statement as to or an admission of fault, culpability or a failure to act, by or on behalf of such indemnified party.

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(b) Each Underwriter, severally and not jointly, agrees to indemnify and hold harmless each of the Company, its respective partners, employees, agents, members, directors and each officer that signed the Registration Statement, 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, and the successors and assigns of all of the foregoing persons from and against any loss, damage, expense, liability or claim (including, without limitation, the reasonable and documented cost of investigation and any reasonable and documented legal fees and other documented expenses reasonably incurred in connection with any suit, action, investigation or proceeding or any claim asserted), joint or several, which the Company or any such person may incur under the Securities Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact made in reliance upon and in conformity with any information relating to the Underwriters furnished in writing by or on behalf of the Representative to the Company expressly for use with reference to the Underwriters in the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company), or arises out of or is based upon any omission or alleged omission to state a material fact in such Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading or (ii) any untrue statement or alleged untrue statement of a material fact made in reliance upon and in conformity with any information relating to the Underwriters furnished in writing by or on behalf of the Representative to the Company expressly for use with reference to the Underwriters in the Prospectus, in any road show or in any free writing prospectus or arises out of or is based upon any omission or alleged omission to state a material fact therein in connection with such information, which material fact was not contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading.

If any Proceeding is brought against the Company or any such person in respect of which indemnity may be sought against the Underwriters pursuant to the foregoing paragraph, the Company or such person shall promptly notify the Representative in writing of the institution of such Proceeding and the Representative shall assume the defense of such Proceeding, including the employment of counsel reasonably satisfactory to such indemnified party and payment of all reasonable and documented fees and expenses; provided, however, that the omission to so notify the Representative shall not relieve the Underwriters from any liability which the Underwriters may have to the Company or any such person or otherwise. The Company or such person shall have the right to employ its own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of the Company or such person unless the employment of such counsel shall have been authorized in writing by the Representative in connection with the defense of such Proceeding or the Representative shall not have, within a reasonable period of time in light of the circumstances, employed counsel to have charge of the defense of such Proceeding or such indemnified party or parties shall have reasonably concluded that there may be defenses available to it or them which are different from or additional to or in conflict with those available to the Representative (in which case the Representative shall not have the right to direct the defense of such Proceeding on behalf of the

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indemnified party or parties, but the Representative may employ counsel and participate in the defense thereof but the fees and expenses of such counsel shall be at the expense of the Representative), in any of which events such reasonable and documented fees and expenses shall be borne by the Representative and paid as incurred (it being understood, however, that the Underwriters shall not be liable for the fees and expenses of more than one separate counsel (in addition to any local counsel) in any one Proceeding or series of related Proceedings in the same jurisdiction representing the indemnified parties who are parties to such Proceeding). The Underwriters shall not be liable for any settlement of any such Proceeding effected without the written consent of the Representative but, if settled with the written consent of the Representative or if there be a final judgment for the plaintiff, the Underwriters agree to indemnify and hold harmless the Company and any such person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested the Underwriters to reimburse the indemnified party for reasonable and documented fees and expenses of counsel as contemplated by the second sentence of this paragraph, then the Underwriters agree that they shall be liable for any settlement of any Proceeding effected without the Representative’s written consent if (i) such settlement is entered into more than 60 business days after receipt by the Representative of the aforesaid request, (ii) the Underwriters shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement and (iii) such indemnified party shall have given the Representative at least 30 days’ prior notice of its intention to settle. The Representative shall not, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened Proceeding in respect of which any indemnified party is a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such Proceeding and does not include any statement as to or an admission of fault, culpability or a failure to act, by or on behalf of such indemnified party.

(c) If the indemnification provided for in this Section 7 is unavailable to an indemnified party under subsections (a) and (b) of this Section 7 or is insufficient to hold an indemnified party harmless in respect of any losses, damages, expenses, liabilities or claims referred to therein, then each applicable indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, damages, expenses, liabilities or claims (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriters, on the other hand, from the offering of the Stock or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and of the Underwriters, on the other, in connection with the statements or omissions which resulted in such losses, damages, expenses, liabilities or claims, as well as any other relevant equitable considerations with respect to such offering. The relative benefits received by the Company, on the one hand, and the Underwriters, on the other, shall be deemed to be in the same respective proportions as the total proceeds from the offering (net of commissions paid hereunder but before deducting expenses) received by the Company, and the total commissions received by the Underwriters hereunder, bear to the aggregate public offering price of the Stock. The relative fault of the Company, on the one hand, and of the Underwriters, on the other,

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shall be determined by reference to, among other things, whether the untrue statement or alleged untrue statement of a material fact or omission or alleged omission relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The amount paid or payable by a party as a result of the losses, damages, expenses, liabilities and claims referred to in this subsection (c) shall be deemed to include any reasonable and documented legal or other fees or expenses reasonably incurred by such party in connection with investigating, preparing to defend or defending any Proceeding.

(d) The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this Section 7 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to in subsection (c) above. Notwithstanding the provisions of this Section 7, each of the Underwriters shall not be required to contribute any amount in excess of commissions received by it under this Agreement. No person found 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.

(e) The Company and the Underwriters agree promptly to notify each other of the commencement of any Proceeding against it and, in the case of the Company, against any of the Company’s officers or directors in connection with the issuance and sale of the Stock, or in connection with the Registration Statement or the Prospectus; provided, that, the omission to so notify shall not relieve the Company or the Underwriters from any liability which such party may have to the Company or the Underwriters, as applicable, or any other person hereunder except to the extent the Company or the Underwriters, as applicable, was materially prejudiced by such omission, which shall include without limitation the loss of any material rights or defenses resulting therefrom.

8. T ERMINATION . 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(k), 6(l) or 6(m) have occurred or if the Underwriters shall decline to purchase the Stock for any reason permitted under this Agreement.

9. R EIMBURSEMENT OF U NDERWRITERS ’ E XPENSES . 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 reimburse the Underwriters for the documented fees and out-of-pocket expenses of Underwriters’ counsel and for such other documented 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, documented travel and lodging expenses of the Underwriters, and upon demand the

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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 required to reimburse any defaulting Underwriter on account of expenses to the extent incurred by such defaulting Underwriter; provided, further that the foregoing shall not limit any reimbursement obligation of the Company to any non-defaulting Underwriter under this Section 9.

10. S UBSTITUTION OF U NDERWRITERS . 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 within forty-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 any non-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 to non-defaulting Underwriters pursuant to Sections 5 and 9 and the provisions of Section 7 and Sections 11 through 21, inclusive, shall not terminate and shall remain in full force and effect.

11. A BSENCE OF F IDUCIARY R ELATIONSHIP . The Company acknowledges and agrees that:

(a) each Underwriter’s responsibility to the Company is solely contractual in nature, the Representative have been retained solely to act as underwriters 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;

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(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 have 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 stockholders, employees or creditors of the Company.

12. S UCCESSORS ; P ERSONS E NTITLED TO B ENEFIT OF A GREEMENT . 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. S URVIVAL OF I NDEMNITIES , R EPRESENTATIONS , W ARRANTIES , 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. N OTICES . 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 RBC Capital Markets, LLC, 3 World Financial Center, 200 Vesey Street, 8th Floor New York, New York 10281, Attention: DCM Transaction Management, Fax: 212-225-6550, with a copy (which shall not constitute notice) to

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Morgan, Lewis & Bockius LLP, 101 Park Avenue, New York, New York, 10178, Attention: David W. Pollak.

(b) if to the Company shall be delivered or sent by mail, telex, facsimile transmission or email to KemPharm, Inc., 1180 Celebration Boulevard, Suite 103, Celebration, Florida 34747, Attention: R. LaDuane Clifton, email: lclifton@kempharm.com, with a copy (which shall not constitute notice) to Cooley LLP, 1299 Pennsylvania Avenue, NW, Suite 700, Washington, DC 20004, Attention: Brent Siler;

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. D EFINITION OF C ERTAIN T ERMS . For purposes of this Agreement, (a) “ business day ” means any day on which the New York Stock Exchange, Inc. is open for trading and not a federal holiday and (b) “ subsidiary ” and “ affiliate ” have the respective meanings set forth in Rule 405 of the Rules and Regulations.

16. G OVERNING L AW . 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 Law. 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. U NDERWRITERS ’ I NFORMATION . 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: the second sentence of the third paragraph in the section of the Prospectus entitled “Underwriting”.

18. A UTHORITY OF THE R EPRESENTATIVE . In connection with this Agreement, the Representative 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. P ARTIAL U NENFORCEABILITY . 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. G ENERAL . 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

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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. C OUNTERPARTS . This Agreement may be signed in any number of counterparts, including by facsimile or other electronic transmission, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

[ Remainder of Page Intentionally Left Blank ]

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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.

[Signature Page to Underwriting Agreement]

SCHEDULE B

Pricing Information

Firm Stock to be Sold: 8,333,334 shares

Offering Price: $3.00 per share

Underwriting Discounts and Commissions: 6%

Gross Proceeds to the Company: $25,000,002

Estimated Net Proceeds to the Company (after underwriting discounts and commissions, but before transaction expenses): $23,500,001.88

SCHEDULE C

None.

SCHEDULE D

Travis C. Mickle, Ph.D.

Christal M.M. Mickle

Travis C. Mickle 2015 Dynasty Trust dated 7/21/2015

Christal M.M. Mickle 2015 Gift Trust dated 7/21/2015

TCM Family Trust u/d/p April 30, 2009

Mickle Family Trust u/d/p April 30, 2009

Mickle Investments LLC

Sven Guenther, Ph.D.

Richard W. Pascoe

Matthew R. Plooster

TD Ameritrade Clearing Inc. Custodian FBO Matthew Ryan Plooster Roth IRA

Bridgepoint Investment Partners I, LLLP

Joseph B. Saluri

Danny L. Thompson

Garrett Bancshares, LTD

David S. Tierney

R. LaDuane Clifton

Gordon K. Johnson

Exhibit I – Form of Lock-Up Agreement

RBC C APITAL M ARKETS , LLC

As Representative of the several Underwriters

c/o RBC Capital Markets, LLC

200 Vesey Street, 8th Floor

New York, New York 10281

Re: KemPharm, Inc. – 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 KemPharm, Inc., a Delaware corporation (the “Company”), and RBC Capital Markets, LLC (“RBC”), as representative of a group of underwriters named therein (collectively, the “Underwriters”), and the other parties thereto (if any), relating to the proposed public offering (the “Offering”) of shares of the common stock, par value $0.0001 per share (the “Common Stock”), of the Company pursuant to a registration statement (the “Registration Statement”) filed or to be filed with the Securities and Exchange Commission (the “SEC”).

In order to induce you and the other Underwriters to enter into the Underwriting Agreement, and in light of the benefits that the Offering 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 the date hereof 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 RBC, directly or indirectly, (i) lend, offer, sell, assign, transfer, pledge, contract to sell, or otherwise dispose of, directly or indirectly, 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 under the Securities Exchange Act of 1934, as the same may be amended or supplemented from time to time (the “Exchange Act”) (such shares, the “Beneficially Owned Shares”)) or securities convertible into or exercisable or exchangeable for 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 Beneficially Owned Shares or securities convertible into or exercisable or exchangeable for 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, (iii) engage in any short selling of the Common Stock, or (iv) publicly announce an intention to effect any transaction specified in clause (i), (ii) or (iii).

The restrictions set forth in the immediately preceding paragraph 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 direct or indirect beneficiaries of which are the undersigned or members of the undersigned’s immediate family, (b) by will or intestate succession upon the death of the undersigned or by operation of law, such as pursuant to a qualified domestic order or in connection with a divorce settlement, or (c) as a bona fide gift to a charity or educational institution,

(2) if the undersigned is a corporation, partnership, limited liability company or other business entity, any transfers to any stockholder, limited partner, general 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 trust, any transfers to a beneficiary of such trust or to the estate of a beneficiary of such trust if, in any such case, such transfer is not for value,

(4) exercises of (a) stock options granted pursuant to an equity incentive or other plan described in the Registration Statement, (b) warrants to purchase shares of Common Stock or other securities or (c) other securities convertible into or exercisable or exchangeable for Common Stock or other securities (including, in each such case, by cashless exercise to the extent permitted by the instruments representing such stock options, warrants or other securities), provided that in any such case the securities issued upon exercise shall be subject to the provisions of this Agreement,

(5) transfers of shares of Common Stock or other securities to the Company in connection with the vesting or exercise of any equity awards granted pursuant to an equity incentive or other plan described in the Registration Statement and held by the undersigned to the extent as may be necessary to satisfy tax withholding obligations pursuant to the Company’s equity incentive or other plans, provided, that in the case of any such transfer no filing under Section 16(a) of the Exchange Act reporting a reduction in beneficial ownership of shares of Common Stock shall be required, and no such filing shall be made voluntarily, in each case, prior to the expiration of the Lock-Up Period,

(6) the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of Common Stock, provided that such plan does not provide for the transfer of Common Stock during the Lock-Up Period, and provided further that no public announcement of the establishment or existence of such plan, and no filing with the SEC or any other regulatory authority in respect thereof, shall be required, and no such public announcement or filing shall be made voluntarily, in each case, prior to the expiration of the Lock-Up Period,

(7) (a) transactions relating to securities acquired in open market transactions after the date of the Offering or (b) if the undersigned is not an officer or director of the Company, transfers or other dispositions of shares of Common Stock purchased by the undersigned in the Offering; provided, that in the case of any such transactions, transfers or dispositions, no public announcement thereof, and no filing with the SEC or any other regulatory authority in respect thereof, shall be required, and no such public announcement or filing shall be made voluntarily, in each case, prior to the expiration of the Lock-Up Period, and

(8) any transfers to the Underwriters pursuant to the Underwriting Agreement;

provided, however, that in the case of any transfer described in clause (1), (2) and (3) above, it shall be a condition to the transfer that (A) the transferee executes and delivers to RBC, 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 RBC, 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 Beneficially Owned Shares or any securities convertible into or exercisable or exchangeable for Common Stock or Beneficially Owned Shares during the Lock-Up Period, 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, by will or intestate succession or by operation of law or, in the case of any transfer pursuant to clause (2) above, such transfer is being made to a stockholder, limited partner, general 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 to a trustee or beneficiary of such trust or to the estate of a beneficiary of such trust and such transfer is not for value. For purposes of this paragraph, “immediate family” shall mean a spouse, 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 of 1933, as amended (the “Securities Act”).

The undersigned further agrees that (i) it will not, during the Lock-Up Period, 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 other Beneficially Owned Shares or any securities convertible into or exercisable or exchangeable for Common Stock or other Beneficially Owned Shares, and (ii) the Company may, with respect to any Common Stock or other Beneficially Owned Shares or any securities convertible into or exercisable or exchangeable for Common Stock or other Beneficially Owned Shares 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. In addition, the undersigned hereby waives (on behalf of the undersigned and all other securityholders of the Company), from the date hereof until the expiration of the Lock-up Period, any and all rights, if any, to request or demand registration, including any right to participate in any Company registration (including without limitation in connection with the Offering), pursuant to the Securities Act of any shares of Common Stock or other Beneficially Owned Shares. The undersigned hereby agrees that, to the extent that the terms of this Agreement conflict with or are in any way inconsistent with any investor rights agreement, registration rights agreement, market standoff agreement or other lock-up agreement related to shares of Common Stock or other Beneficially Owned Shares or any securities convertible into or exercisable or exchangeable for Common Stock or other Beneficially Owned Shares to which the undersigned may be party, this Agreement supersedes such investor rights agreement, registration rights agreement, market standoff agreement or other lock-up agreement.

If the undersigned is an officer or director of the Company, RBC agrees that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of shares of Common Stock, RBC will notify the Company of the impending release or waiver. The provisions of this paragraph will not apply if (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

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. The undersigned understands that the Company and the Underwriters are relying on this Agreement in proceeding towards consummation of the Offering. 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.

The undersigned acknowledges and agrees that whether or not the Offering actually occurs depends on a number of factors, including market conditions.

If (i) the Underwriting Agreement terminates or is terminated (other than the provisions thereof which survive termination) prior to the payment for and delivery of the shares proposed for sale under the Registration Statement, (ii) RBC, on the one hand, or the Company, on the other hand, has advised in writing, prior to the execution of the Underwriting Agreement, that it has determined not to proceed with the Offering, (iii) the Company notifies the undersigned in writing that it does not intend to proceed with the Offering, withdraws the Registration Statement or deregisters all of the shares covered by the Registration Statement, or (iv) the Underwriting Agreement has not been executed on or before December 31, 2018, provided that the Company may by written notice to the undersigned prior to December 31, 2018 extend such date for a period of up to three additional months, then this Agreement shall terminate immediately upon such date and be of no further force or effect and the undersigned shall automatically be released from all of his, her or its obligations under this Agreement.

The undersigned hereby consents to receipt of this Agreement in electronic form and understands and agrees that execution and delivery of this Agreement by facsimile transmission, electronic mail or other electronic transmission is legal, valid and binding for all purposes. This Agreement shall be governed by and construed in accordance with the laws of the State of New York.

[signature page follows]