Shares Rib-X Pharmaceuticals, Inc. Common Stock ($0.001 Par Value) EQUITY UNDERWRITING AGREEMENT

EX-1.1 2 d255425dex11.htm FORM OF UNDERWRITING AGREEMENT Form of Underwriting Agreement

Exhibit 1.1

— Shares

Rib-X Pharmaceuticals, Inc.

Common Stock

($0.001 Par Value)

EQUITY UNDERWRITING AGREEMENT

—, 2012

Deutsche Bank Securities Inc.

As Representative of the

Several Underwriters

c/o Deutsche Bank Securities Inc.

60 Wall Street, 4^th Floor

New York, New York 10005

Ladies and Gentlemen:

Rib-X Pharmaceuticals, Inc., a Delaware corporation (the “Company”), proposes to sell to the several underwriters (the “Underwriters”) named on Schedule I hereto for whom you are acting as representative (the “Representative”) an aggregate of — shares (the “Firm Shares”) of the Company’s common stock, $0.001 par value (the “Common Stock”). The respective amounts of the Firm Shares to be so purchased by the several Underwriters are set forth opposite their names on Schedule I hereto. The Company also proposes to sell at the Underwriters’ option an aggregate of up to — additional shares of the Company’s Common Stock (the “Option Shares”) to cover over-allotments in the sale of the Firm Shares as set forth below.

As the Representative, you have advised the Company (a) that you are authorized to enter into this Agreement on behalf of the several Underwriters, and (b) that the several Underwriters are willing, acting severally and not jointly, to purchase the numbers of Firm Shares set forth opposite their respective names on Schedule I hereto, plus their pro rata portion of the Option Shares if you elect to exercise the over-allotment option in whole or in part for the accounts of the several Underwriters. The Firm Shares and the Option Shares (to the extent the aforementioned option is exercised) are herein collectively called the “Shares.”

In consideration of the mutual agreements contained herein and of the interests of the parties in the transactions contemplated hereby, the parties hereto agree as follows:

1. REPRESENTATIONS AND WARRANTIES OF THE COMPANY.

The Company represents and warrants to each of the Underwriters as follows:

(a) A registration statement on Form S-1 (File No. 333-178188) with respect to the Shares has been prepared by the Company in conformity with the requirements of the Securities Act of 1933, as amended (the “Act”), and the rules and regulations (the “Rules and Regulations”) of the Securities and Exchange Commission (the “Commission”) thereunder and has been filed with the Commission. Copies of such registration statement, including any amendments thereto, the preliminary prospectuses (meeting the requirements of the Rules and Regulations) contained therein and the exhibits, financial statements and schedules, as finally amended and revised, have heretofore been delivered by the Company to you. Such registration statement, together with any registration statement filed by the Company pursuant to Rule 462(b) under the Act, is herein referred to as the “Registration Statement,” which shall be deemed to include all information omitted therefrom in reliance upon Rules 430A, 430B or 430C under the Act and contained in the Prospectus referred to below, has become effective under the Act and no post-effective amendment to the Registration Statement has been filed as of the date of this equity underwriting agreement (this “Agreement”). “Prospectus” means the form of prospectus first filed with the Commission pursuant to and within the time limits described in Rule 424(b) under the Act. The preliminary prospectus included in the Registration Statement immediately prior to the time the Registration Statement becomes effective is herein referred to as a “Preliminary Prospectus.”

(b) As of the Applicable Time (as defined below) and as of the Closing Date or the Option Closing Date, 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 Preliminary Prospectus and the information included on Schedule II hereto, all considered together (collectively, the “General Disclosure Package”), nor (ii) any individual Limited Use Free Writing Prospectus (as defined below), when considered together with the General Disclosure Package, included or will include any untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company makes no representations or warranties as to information contained in or omitted from the General Disclosure Package or any Issuer Free Writing Prospectus, in reliance upon, and in conformity with, written information furnished to the Company by or on behalf of any Underwriter through the Representative, specifically for use therein, it being understood and agreed that the only such information is that described in Section 12 hereof.

As used in this subsection and elsewhere in this Agreement:

“Applicable Time” means — [a/p]m (New York time) on the date of this Agreement or such other time as agreed to by the Company and the Representative.

“General Use Free Writing Prospectus” means any Issuer Free Writing Prospectus (other than a “bona fide electronic road show,” as defined in Rule 433 (the “Bona Fide Electronic Road Show”) that is identified on Schedule III hereto.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 under the Act, including without limitation any “free writing prospectus” (as defined in Rule 405 of the Rules and Regulations of the Act (“Rule 405”)) relating to the Shares that is (i) required to be filed with the Commission by the Company, (ii) a “road show that is a written communication” within the meaning of Rule 433(d)(8)(i), whether or not required to be filed with the Commission or (iii) excepted from filing with the Commission pursuant to Rule 433(d)(5)(i) because it contains a description of the Shares or of the offering that does not reflect the final terms, in each case 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).

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

(c) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Delaware, with requisite power and authority to own or lease its properties and conduct its business as described in the Registration Statement, the General Disclosure Package and the Prospectus. Each of the subsidiaries of the Company as listed in Exhibit A hereto (collectively, the “Subsidiaries”) has been duly organized and is validly existing as a corporation, limited liability company or similar entity in good standing under the laws of the jurisdiction of its organization with requisite power and authority to own or lease its properties and conduct its business as described in the Registration Statement, the General Disclosure Package and the Prospectus. The Subsidiaries are the only subsidiaries, direct or indirect, of the Company. The Company and each of the Subsidiaries are duly qualified to transact business in all jurisdictions in which the conduct of their business requires such qualification except where the failure to be so qualified would not (i) have, individually or in the aggregate, a material adverse effect on the earnings, business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company and of the Subsidiaries taken as a whole or (ii) prevent the consummation of the transactions contemplated hereby (the occurrence of any such effect or any such prevention described in the foregoing clauses (i) and (ii) being referred to as a “Material Adverse Effect”). The outstanding shares of capital stock of each of the Subsidiaries have been duly authorized and validly issued, are fully paid and non-assessable and to the extent shown in Exhibit A hereto are owned by the Company or another Subsidiary free and clear of all liens, encumbrances and equities and claims; and no options, warrants or other rights to purchase, agreements or other obligations to issue or other rights to convert any obligations into shares of capital stock or ownership interests in the Subsidiaries are outstanding.

(d) The outstanding shares of Common Stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable; the Shares to be issued and sold by the Company in the public offering contemplated herein have been duly authorized and when

issued and paid for as contemplated herein will be validly issued, fully paid and non-assessable; and no preemptive or similar rights of stockholders exist with respect to any of the Shares or the issue and sale thereof. Neither the filing of the Registration Statement nor the offering or sale of the Shares as contemplated by this Agreement gives rise to any rights, other than those which have been waived or satisfied, for or relating to the registration of any shares of Common Stock.

(e) The information set forth under the caption “Capitalization” in the Registration Statement and the Prospectus (and any similar section or information contained in the General Disclosure Package) is true and correct in all material respects. All of the Shares conform to the description thereof contained in the Registration Statement, the General Disclosure Package and the Prospectus. The form of certificates for the Shares conforms to the corporate law of the jurisdiction of the Company’s incorporation and to any requirements of the Company’s organizational documents. Subsequent to the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, except as otherwise described therein or in this Agreement, the Company has not: (i) issued any securities; (ii) incurred any material liability or obligation, direct or contingent, for borrowed money; or (iii) declared or paid any dividend or made any other distribution on or in respect to its capital stock.

(f) The Commission has not issued an order preventing or suspending the use of the Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus relating to the proposed offering of the Shares, and no proceeding for that purpose or pursuant to Section 8A of the Act has been instituted or, to the Company’s knowledge, threatened by the Commission. The Registration Statement, as of its effective date, contained and as of the date hereof contains, and the Prospectus and any amendments or supplements thereto will contain, all statements which are required to be stated therein by, and will conform in all material respects to, the requirements of the Act and the Rules and Regulations. The Registration Statement and any amendments thereto, as of its effective date, the date hereof and the Closing Date and the Option Closing Date, as the case may be, did not contain, do not contain, and will not contain, any untrue statement of a material fact and do not omit, and will not omit, to state a material fact required to be stated therein or necessary to make the statements therein not misleading. The Prospectus and any amendments and supplements thereto, as of its date, the date hereof and the Closing Date and any Option Closing Date, as the case may be, did not contain, do not contain, and will not contain, any untrue statement of a material fact; and did not omit, do not omit, and will not omit, to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company makes no representations or warranties as to information contained in or omitted from the Registration Statement or the Prospectus, or any such amendment or supplement, in reliance upon, and in conformity with, written information furnished to the Company by or on behalf of any Underwriter through the Representative, specifically for use therein, it being understood and agreed that the only such information is that described in Section 12 hereof.

(g) No Issuer Free Writing Prospectus conflicts or will conflict with the information contained in the Registration Statement or the Prospectus, and any preliminary or

other prospectus deemed to be a part thereof that has not been superseded or modified. The Company has made available a Bona Fide Electronic Road Show in compliance with Rule 433(d)(8)(ii) such that no filing of any “road show” (as defined in Rule 433(h)) is required in connection with the offering of the Shares.

(h) The Company has not, directly or indirectly, distributed and will not distribute any offering material in connection with the offering and sale of the Shares other than the Preliminary Prospectus, the Prospectus, any Permitted Free Writing Prospectus (defined below) and other materials, if any, permitted under the Act and consistent with Section 4(b) hereof. The Company will file with the Commission all Issuer Free Writing Prospectuses in the time required under Rule 433(d) under the Act; provided that the Company has satisfied or will satisfy the conditions in Rule 433 under the Act to avoid a requirement to file with the Commission any electronic road show.

(i) At the time of filing the Registration Statement and (ii) as of the date hereof (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an “ineligible issuer” (as defined in Rule 405 under the Act, without taking into account any determination by the Commission pursuant to Rule 405 under the Act that it is not necessary that the Company be considered an ineligible issuer), including, without limitation, for purposes of Rules 164 and 433 under the Act with respect to the offering of the Shares as contemplated by the Registration Statement.

(j) The consolidated financial statements of the Company and its consolidated subsidiaries, together with related notes and schedules as set forth in the Registration Statement, the General Disclosure Package and the Prospectus, comply in all material respects with the applicable requirements of the Act and present fairly the financial position and the results of operations and cash flows of the Company and the consolidated Subsidiaries, at the indicated dates and for the indicated periods. Such financial statements and related schedules have been prepared in accordance with United States generally accepted principles of accounting (“GAAP”), consistently applied throughout the periods involved, except as disclosed therein, and all adjustments necessary for a fair presentation of results for such periods have been made. The summary and selected consolidated financial and statistical data included in the Registration Statement, the General Disclosure Package and the Prospectus present fairly the information shown therein and such data has been compiled on a basis consistent with the financial statements presented therein and the books and records of the Company. The pro forma financial statements and other pro forma financial information included in the Registration Statement, the General Disclosure Package and the Prospectus present fairly the information shown therein, have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements, have been properly compiled on the pro forma bases described therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions or circumstances referred to therein. All disclosures contained in the Registration Statement, the General Disclosure Package and the Prospectus regarding “non-GAAP financial measures” (as such term is defined by the Rules and Regulations) comply with Regulation G of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Item 10 of Regulation S-K

under the Act, to the extent applicable. The Company and the Subsidiaries do not have any material liabilities or obligations, direct or contingent (including any off-balance sheet obligations or any “variable interest entities” within the meaning of Financial Accounting Standards Board Interpretation No. 46), not disclosed in the Registration Statement, the General Disclosure Package and the Prospectus. There are no financial statements (historical or pro forma) that are required to be included in the Registration Statement, the General Disclosure Package or the Prospectus that are not included as required.

(k) PricewaterhouseCoopers LLP, who have certified certain of the financial statements filed with the Commission as part of the Registration Statement, the General Disclosure Package and the Prospectus, is an independent registered public accounting firm with respect to the Company and the Subsidiaries within the meaning of the Act and the applicable Rules and Regulations and the Public Company Accounting Oversight Board (United States) (the “PCAOB”).

(l) No labor disturbance by or dispute with employees of the Company or any of the Subsidiaries exists or, to the knowledge of the Company, is contemplated or threatened.

(m) Solely to the extent that the Sarbanes-Oxley Act of 2002, as amended, and the rules and regulations promulgated by the Commission and the NASDAQ Global Market thereunder (collectively, the “Sarbanes-Oxley Act”) have been applicable to the Company, there is and has been no failure on the part of the Company to comply in all material respects with any provision of the Sarbanes-Oxley Act. The Company has taken all necessary actions to ensure that it is in compliance with all provisions of the Sarbanes-Oxley Act that are in effect and with which the Company is required to comply (including Section 402 related to loans) and is actively taking steps to ensure that it will be in compliance with other provisions of the Sarbanes-Oxley Act not currently in effect or which will become applicable to the Company. As of the date of the initial filing of the registration statement referred to in Section 1(a)(i) hereof, there were no outstanding personal loans made, directly or indirectly, by the Company to any director or executive officer of the Company.

(n) There is no legal, governmental, administrative or regulatory investigation, action, suit, claim or proceeding pending or, to the knowledge of the Company, threatened against the Company or any of the Subsidiaries, or to which any property of the Company or the Subsidiaries is, or to the knowledge of the Company, would reasonably be expected to be, subject, before any court or regulatory or administrative agency or otherwise which if determined adversely to the Company or any of the Subsidiaries would, individually or in the aggregate, have a Material Adverse Effect. There are no current or pending legal, governmental, administrative or regulatory investigations, actions, suits, claims or proceedings that are required under the Act to be described in the Registration Statement, the General Disclosure Package or the Prospectus that are not so described in the Registration Statement, the General Disclosure Package or the Prospectus. There are no statutes, regulations or contracts or other documents that are required under the Act to be filed as exhibits to the Registration Statement or described in the Registration Statement, the General Disclosure Package or the Prospectus that are not so filed as exhibits to the Registration Statement or described in the Registration Statement, the General Disclosure Package or the Prospectus.

(o) The Company and the Subsidiaries have good and marketable title to all of the material properties and assets reflected in the consolidated financial statements hereinabove described or described in the Registration Statement, the General Disclosure Package and the Prospectus, subject to no lien, mortgage, pledge, charge or encumbrance of any kind except those reflected in such financial statements or described in the Registration Statement, the General Disclosure Package and the Prospectus or which (i) do not materially interfere with the use made and proposed to be made of such property by the Company and the Subsidiaries or (ii) would, individually or in the aggregate, not have a Material Adverse Effect. The Company and the Subsidiaries occupy their leased properties under valid and binding leases conforming in all material respects to the description thereof set forth in the Registration Statement, the General Disclosure Package and the Prospectus.

(p) The Company and the Subsidiaries have filed all U.S. federal, state, local and foreign tax returns which have been required to be filed and have paid all taxes indicated by such returns and all assessments received by them or any of them to the extent that such taxes have become due and are not being contested in good faith and for which an adequate reserve or accrual has been established in accordance with GAAP. All tax liabilities have been adequately provided for in the financial statements of the Company, and the Company does not know of any actual or proposed additional material tax assessments.

(q) Since the date of the most recent financial statements included in the Registration Statement, the General Disclosure Package and the Prospectus, (i) there has not been any material adverse change or any development involving a prospective material adverse change in or affecting the earnings, business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company and the Subsidiaries taken as a whole, whether or not occurring in the ordinary course of business, (ii) there has not been any material transaction entered into or any material transaction that is probable of being entered into by the Company or the Subsidiaries, other than transactions in the ordinary course of business and changes and transactions described in the Registration Statement, the General Disclosure Package and the Prospectus, as each may be amended or supplemented, and (iii) neither the Company nor any of its subsidiaries has sustained any loss or interference with its business that is material to the Company and the Subsidiaries taken as a whole and that is either from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in the Registration Statement, the General Disclosure Package and the Prospectus.

(r) Neither the Company nor any of the Subsidiaries is or with the giving of notice or lapse of time or both, will be, (i) in violation of its certificate or articles of incorporation, charter, by-laws, certificate of formation, limited liability company agreement, partnership agreement or other organizational documents, as applicable, (ii) in violation of or in default under any agreement,

lease, contract, indenture or other instrument or obligation to which it is a party or by which it, or any of its properties, is bound or (iii) in violation of any law, order, rule or regulation judgment, order, writ or decree applicable to the Company or any subsidiary of any court or of any government, regulatory body or administrative agency or other governmental body having jurisdiction over the Company or any Subsidiary, or any of their properties or assets, except in the case of clauses (ii) and (iii) above, for such violations or defaults as would not, individually or in the aggregate, have a Material Adverse Effect. The execution and delivery of this Agreement and the consummation of the transactions herein contemplated and the fulfillment of the terms hereof do not and will not conflict with or result in a breach of any of the terms or provisions of, or constitute a default under, (i) any indenture, mortgage, deed of trust or other agreement or instrument to which the Company or any Subsidiary is a party or by which the Company or any Subsidiary or any of their respective properties is bound, (ii) the certificate of incorporation or formation, articles of incorporation or association, charter, by-laws or other organizational documents, as applicable, of the Company, or (iii) any law, order, rule or regulation judgment, order, writ or decree applicable to the Company or any Subsidiary of any court or of any government, regulatory body or administrative agency or other governmental body having jurisdiction over the Company or any subsidiary, or any of their properties or assets.

(s) The execution and delivery of, and the performance by the Company of its obligations under, this Agreement has been duly and validly authorized by all necessary corporate, limited liability company or similar applicable action on the part of the Company, and this Agreement has been duly executed and delivered by the Company.

(t) Each approval, consent, order, authorization, designation, declaration or filing by or with any regulatory, administrative or other governmental body necessary in connection with the execution and delivery by the Company of this Agreement and the consummation of the transactions herein contemplated has been obtained or made and is in full force and effect (except such additional steps as may be required by the Commission, the Financial Industry Regulatory Authority, Inc. (“FINRA”), the NASDAQ Global Market, or such additional steps as may be necessary to qualify the Shares for public offering by the Underwriters under state or foreign securities or Blue Sky laws).

(u) Except as would not, individually or in the aggregate, have a Material Adverse Effect, (i) the Company and each of the Subsidiaries hold all licenses, registrations, certificates and permits from governmental authorities (collectively, “Governmental Licenses”) which are necessary to the conduct of their business, (ii) are in compliance with the terms and conditions of all Governmental Licenses, and all Governmental Licenses are valid and in full force and effect, and (iii) have not received any written notice of proceedings relating to the revocation or modification of any Governmental License.

(v) The Company and the Subsidiaries own or possess the right to use all patents, inventions, trademarks and copyrights, and registrations and applications for registration of any of the foregoing (collectively, “Intellectual Property”) necessary to conduct their business as presently conducted and currently contemplated to be conducted in the future as set forth in the

Registration Statement, the General Disclosure Package or the Prospectus. To the knowledge of the Company, neither the Company nor any of the Subsidiaries, whether through their respective products and services or the conduct of their respective businesses, has infringed, misappropriated, conflicted with or otherwise violated, or is currently infringing, misappropriating, conflicting with or otherwise violating, and none of the Company or the Subsidiaries have received any communication or notice of infringement of, misappropriation of, conflict with or violation of, any Intellectual Property of any other person or entity. Neither the Company nor any of the Subsidiaries has received any communication or notice alleging that by conducting their business as set forth in the Registration Statement, the General Disclosure Package or the Prospectus, such parties would infringe, misappropriate, conflict with, or violate, any of the Intellectual Property of any other person or entity. The Company knows of no infringement, misappropriation or violation by others of Intellectual Property owned by or licensed to the Company or the Subsidiaries. The Company and its Subsidiaries have taken all reasonable steps necessary to secure their interests in such Intellectual Property from their employees and contractors and to protect the confidentiality of all of their confidential information and trade secrets.

(w) None of the Intellectual Property employed by the Company or the Subsidiaries has been obtained or is being used by the Company or the Subsidiaries in violation of any contractual obligation binding on the Company or any of the Subsidiaries or, to the knowledge of the Company, any of their respective officers, directors or employees or otherwise in violation of the rights of any persons.

(x) The Company and the Subsidiaries own or have a valid right to access and use all computer systems, networks, hardware, software, databases, websites, and equipment used to process, store, maintain and operate data, information, and functions used in connection with the business of the Company and the Subsidiaries (the “Company IT Systems”), except as would not, individually or in the aggregate, have a Material Adverse Effect. The Company IT Systems are adequate for, and operate and perform in all material respects as required in connection with, the operation of the business of the Company and the Subsidiaries as currently conducted, except as would not, individually or in the aggregate, have a Material Adverse Effect. The Company and the Subsidiaries have implemented commercially reasonable backup, security and disaster recovery technology consistent in all material respects with applicable regulatory standards and customary industry practices.

(y) Neither the Company nor, to the Company’s knowledge, any of its affiliates, has taken or may take, directly or indirectly, any action designed to cause or result in, or which has constituted or which might reasonably be expected to constitute, the stabilization or manipulation of the price of the shares of Common Stock to facilitate the sale or resale of the Shares.

(z) Neither the Company nor any Subsidiary is or, after giving effect to the offering and sale of the Shares contemplated hereunder and the application of the net proceeds from such sale as described in the Registration Statement, the General Disclosure Package and the Prospectus, will be required to register as 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 (collectively, the “1940 Act”).

(aa) The Company and the Subsidiaries maintain systems of “internal control over financial reporting” (as defined in Rule 13a-15(f) of the Exchange Act) that comply with the requirements of the Exchange Act and have been designed by, or under the supervision of, their respective principal executive and principal financial officers, or persons performing similar functions, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP, including, but not limited to, internal accounting controls sufficient to provide reasonable assurance that: (i) transactions are executed in accordance with management’s general or specific authorization; (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; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences. There are no material weaknesses in the Company’s internal control over financial reporting, and there has been no change in internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus. The Company’s auditors and the Audit Committee of the Board of Directors of the Company have been advised of: (i) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which have adversely affected or are reasonably likely to adversely affect the Company’s ability to record, process, summarize and report financial information; and (ii) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal controls over financial reporting.

(bb) The Company has established and maintains “disclosure controls and procedures” (as defined in Rules 13a-14(c) and 15d-14(c) under the Exchange Act); the Company’s “disclosure controls and procedures” are reasonably designed to ensure that all information (both financial and non-financial) required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the rules and regulations under the Exchange Act, and that all such information is accumulated and communicated to the Company’s management as appropriate to allow timely decisions regarding required disclosure and to make the certifications of the Chief Executive Officer and Chief Financial Officer of the Company required under the Exchange Act with respect to such reports.

(cc) The statistical, industry-related and market-related data included in the Registration Statement, the General Disclosure Package and the Prospectus are based on or derived from sources which the Company reasonably and in good faith believes are reliable and accurate, and such data agree with the sources from which they are derived.

(dd) The operations of the Company and the Subsidiaries are and have been conducted at all times in compliance with the applicable financial record-keeping and reporting requirements of the Bank Secrecy Act, as amended by Title III of the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (USA PATRIOT Act), the Currency and Foreign Transactions Reporting Act of 1970, as amended, and the applicable money laundering statutes of jurisdictions where the Company and the Subsidiaries conduct business, the applicable rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”), and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any or the Subsidiaries with respect to the Money Laundering Laws is pending or, to the Company’s knowledge, threatened.

(ee) Neither the Company nor, to the Company’s knowledge, any director, officer, agent, employee or affiliate of the Company or any of the Subsidiaries is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of the offering, 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.

(ff) Neither the Company nor any of the Subsidiaries nor, to the knowledge of the Company, any director, officer, agent, employee or affiliate of the Company or any of the Subsidiaries: (i) has used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity: (ii) has made any direct or indirect unlawful contribution or payment to any official of, or candidate for, or any employee of, any federal, state or foreign office from corporate funds; (iii) has made any bribe, unlawful rebate, payoff, influence payment, kickback or other unlawful payment; or (iv) is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (collectively, the “FCPA”), including, without limitation, the FCPA prohibition against taking corrupt actions in furtherance of an offer, payment, promise to pay, or authorization of the payment of anything of value, to any “foreign official” (as such term is defined in the FCPA) or any candidate for foreign political office (a “Foreign Official”), or to any other person while knowing that all or some portion of the consideration remitted to that person will benefit or be offered, given, or promised to a Foreign Official for the purpose of (a) influencing any act, decision, or failure to act by a Foreign Official in his or her official capacity; or (b) inducing such Foreign Official to use his or her influence with any Governmental Authority (as defined below) to affect any act or decision of the Governmental Authority, in order to obtain, retain, or direct business or secure an improper advantage, in contravention of the FCPA. The Company, the Subsidiaries and, to the knowledge of the Company, their affiliates have each conducted their businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(gg) The Company and each of the Subsidiaries carry, or are covered by, insurance, from insurers of recognized financial responsibility, in such amounts and covering such risks as is adequate for the conduct of their respective businesses and the value of their respective properties and as is prudent and customary for companies engaged in similar businesses; neither the Company nor any of the Subsidiaries have been refused any coverage under insurance policies sought or applied for; and the Company and the Subsidiaries have no reason to believe that they will not be able to renew their existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue their respective businesses at a cost that would not, individually or in the aggregate, have a Material Adverse Effect.

(hh) Each “employee benefit plan” (within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder (“ERISA”)) for which the Company or any member of its “Controlled Group” (defined as any organization that is a member of a controlled group of corporations within the meaning of Section 414 of the Internal Revenue Code of 1986, as amended (the “Code”)) would have liability (each a “Plan”) is in compliance in all material respects with all presently applicable statutes, rules and regulations, including ERISA and the Code; (ii) with respect to each Plan subject to Title IV of ERISA, (a) no “reportable event” (as defined in Section 4043 of ERISA) has occurred for which the Company or any member of its Controlled Group would have any liability and (b) neither the Company nor any member of its Controlled Group has incurred or expects to incur any material liability under Title IV of ERISA (other than for contributions to the Plan or premiums payable to the Pension Benefit Guaranty Corporation, in each case in the ordinary course and without default); (iii) no Plan which is subject to Section 412 of the Code or Section 302 of ERISA has failed to satisfy the minimum funding standard within the meaning of such sections of the Code or ERISA; and (iv) each Plan that is intended to be qualified under Section 401(a) of the Code is so qualified in all material respects and nothing has occurred, whether by action or by failure to act, which would cause the loss of such qualification.

(ii) To the knowledge of the Company, there are no affiliations or associations between any member of FINRA and any of the Company’s officers, directors or 5% or greater securityholders, except as set forth in the Registration Statement.

(jj) The Company and each Subsidiary (i) is in compliance with any and all applicable foreign, federal, state and local laws, statutes, rules, regulations and judgments or orders of any governmental agency or body or any court, domestic or foreign, relating to the protection of the environment or human health or safety, or to the manufacture, use, generation, treatment, storage, disposal, release or threatened release of hazardous or toxic substances, pollutants, contaminants or wastes, or the arrangement of such activities (“Environmental Laws”), (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses, and (iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in

the aggregate, have a Material Adverse Effect. There are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, singly or in the aggregate, have a Material Adverse Effect.

(kk) The Shares have been approved for listing subject to notice of issuance on the NASDAQ Global Market.

(ll) There are no relationships, direct or indirect, or related-party transactions involving the Company or any of the Subsidiaries or any other person required to be described in the Registration Statement and the Prospectus which have not been described in such documents and the General Disclosure Package as required.

(mm) No Subsidiary of the Company is currently prohibited, directly or indirectly, from paying any dividends to the Company, from making any other distribution on such Subsidiary’s capital stock, from repaying to the Company any loans or advances to such Subsidiary from the Company or from transferring any of such Subsidiary’s property or assets to the Company or any other Subsidiary of the Company.

(nn) Neither the Company nor any of the Subsidiaries is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against the Company or any of the Subsidiaries or any Underwriter for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Shares.

(oo) Except as described in the Registration Statement, the General Disclosure Package and the Prospectus, and except as would not, singly or in the aggregate, result in a Material Adverse Effect: (i) neither the Company nor any of the Subsidiaries has received any FDA Form 483, notice of adverse filing, warning letter or other written notice from the U.S. Food and Drug Administration (“FDA”) or any other federal, state or foreign governmental authority (collectively, “Governmental Authority”) alleging or asserting noncompliance with any Applicable Laws (as defined in clause (ii) below) or Authorizations (as defined in clause (iii) below); (ii) the Company and each of the Subsidiaries is and has been in compliance with statutes, rules, regulations, policies and administrative guidance applicable to the Company and its Subsidiaries for the ownership, testing, development, manufacture, packaging, processing, use, distribution, marketing, labeling, promotion, sale, offer for sale, storage, import, export or disposal of any product manufactured or distributed by the Company, including without limitation, the Federal Food, Drug, and Cosmetic Act, and the regulations promulgated pursuant to such laws (collectively, “Applicable Laws”); (iii) the Company and each of the Subsidiaries possesses all licenses, certificates, approvals, clearances, authorizations, permits and supplements or amendments thereto required by any such Applicable Laws to carry on its businesses as now conducted and, to the extent obtainable as of the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, as proposed to be conducted as described in the Registration Statement, the General Disclosure Package and the Prospectus (“Authorizations”) and such

Authorizations are valid and in full force and effect and the Company is not in violation of any term of any such Authorizations; (iv) neither the Company nor any of the Subsidiaries has received written notice of any ongoing claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any Governmental Authority or third party alleging that any product operation or activity is in violation of any Applicable Laws or Authorizations or has any knowledge that any such Governmental Authority or third party is considering any such claim, litigation, arbitration, action, suit, investigation or proceeding; (v) neither the Company nor any of the Subsidiaries has received written notice that any Governmental Authority has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations or has any knowledge that any such Governmental Authority is considering such action; and (vi) the Company and each of the Subsidiaries has filed, obtained, maintained or submitted all reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments as required by any Applicable Laws or Authorizations and, to the knowledge of the Company, all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments were complete, correct and not misleading on the date filed (or were corrected or supplemented by a subsequent submission).

(pp) The research, studies and tests conducted by or, to the knowledge of the Company, on behalf of the Company and the Subsidiaries have been and, if still pending, are being conducted in accordance with experimental protocols and procedures pursuant to all Applicable Laws and Authorizations; the descriptions of the results of such research, studies and tests contained in the Registration Statement, the General Disclosure Package and the Prospectus are accurate and fairly present the data derived from such research, studies, and tests; except to the extent disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, the Company is not aware of any research, studies or tests, the results of which the Company believes reasonably call into question the research, study or test results described or referred to in the Registration Statement, the General Disclosure Package and the Prospectus when viewed in the context in which such results are described; and neither the Company nor any of the Subsidiaries has received any written notices from any Governmental Authority requiring the termination, suspension or material modification of any research, study or test conducted by or on behalf of the Company or the Subsidiaries, as applicable. To the knowledge of the Company, except to the extent disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, there have been no serious adverse events resulting from any research, study or test conducted by or on behalf of the Company or the Subsidiaries.

(qq) Since that date of the preliminary prospectus included in the Registration Statement filed with the Commission on April 24, 2012 (or, if earlier, the first date on which the Company engaged directly or through any Person authorized to act on its behalf in any communication in reliance on Section 5(d) of the Securities Act) 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”).

(rr) The Company (a) has not alone engaged in communications with potential investors in reliance on Section 5(d) of the Securities Act other than communications with the

consent of the Representatives with entities that are qualified institutional buyers within the meaning of Rule 144A under the Securities Act or institutions that are accredited investors within the meaning of Rule 501 under the Securities Act and (b) has not authorized anyone other than the Underwriters to engage in such communications. The Company reconfirms that the Underwriters have been authorized to act on its behalf in communicating with potential investors in reliance on Section 5(d) of the Securities Act. The Company has not distributed any Testing-the-Waters Writings. “Testing-the-Waters Writing” means any written communication within the meaning of Rule 405 under the Securities Act relating to the Securities that would, but for the provisions of Section 5(d) of the Securities Act, be a “free writing prospectus” as defined in Rule 405 under the Securities Act but without regard to whether a registration statement has been filed.

2. PURCHASE, SALE AND DELIVERY OF THE FIRM SHARES.

(a) On the basis of the representations, warranties and covenants herein contained, and subject to the conditions herein set forth, the Company agrees to sell to the Underwriters and each Underwriter agrees, severally and not jointly, to purchase, at a price of $— per share, the number of Firm Shares set forth opposite the name of each Underwriter on Schedule I hereto, subject to adjustments in accordance with Section 8 hereof.

(b) Payment for the Firm Shares to be sold hereunder is to be made in federal (same day) funds against delivery of certificates therefor to the Representative for the several accounts of the Underwriters. Such payment and delivery are to be made through the facilities of The Depository Trust Company, New York, New York, at 10:00 a.m., New York City time, on the third business day after the date of this Agreement or at such other time and date not later than five business days thereafter as you and the Company shall agree upon, such time and date being herein referred to as the “Closing Date”. As used herein, “business day” means a day on which the NASDAQ Global Market is open for trading and on which banks in New York are open for business and are not permitted by law or executive order to be closed.

(c) In addition, on the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company hereby grants an option to the several Underwriters to purchase the Option Shares at the price per share as set forth in Section 2(a) hereof. The option granted hereby may be exercised in whole or in part by giving written notice (i) at any time before the Closing Date and (ii) only once thereafter within 30 days after the date of this Agreement, by you, as Representative of the several Underwriters, to the Company setting forth the number of Option Shares as to which the several Underwriters are exercising the option and the time and date at which such certificates are to be delivered. The time and date at which certificates for Option Shares are to be delivered shall be determined by the Representative but shall not be earlier than three nor later than 10 full business days after the exercise of such option, nor in any event prior to the Closing Date (such time and date being herein referred to as the “Option Closing Date”). If the date of exercise of the option is three or more days before the Closing Date, the notice of exercise shall set the Closing Date as the Option Closing Date. The number of Option Shares to be purchased by each Underwriter shall be in the same proportion to the total number of

Option Shares being purchased as the number of Firm Shares being purchased by such Underwriter bears to the total number of Firm Shares, adjusted by you in such manner as to avoid fractional shares. The option with respect to the Option Shares granted hereunder may be exercised only to cover over-allotments in the sale of the Firm Shares by the Underwriters. You, as Representative of the several Underwriters, may cancel such option at any time prior to its expiration by giving written notice of such cancellation to the Company. To the extent, if any, that the option is exercised, payment for the Option Shares shall be made on the Option Closing Date in federal (same day funds) through the facilities of The Depository Trust Company in New York, New York drawn to the order of the Company.

3. OFFERING BY THE UNDERWRITERS.

It is understood that the several Underwriters are to make a public offering of the Firm Shares as soon as the Representative deems it advisable to do so. The Firm Shares are to be initially offered to the public at the initial public offering price set forth in the Prospectus. The Representative may from time to time thereafter change the public offering price and other selling terms.

It is further understood that you will act as the Representative for the Underwriters in the offering and sale of the Shares in accordance with a Master Agreement Among Underwriters entered into by you and the several other Underwriters.

4. COVENANTS OF THE COMPANY.

The Company covenants and agrees with the several Underwriters that:

(a) The Company will (i) prepare and timely file with the Commission under Rule 424(b) under the Act a Prospectus in a form approved by the Representative (such approval not to be unreasonably withheld) containing information previously omitted at the time of effectiveness of the Registration Statement in reliance on Rules 430A, 430B or 430C under the Act, and (ii) not file any amendment to the Registration Statement or distribute an amendment or supplement to the General Disclosure Package or the Prospectus of which the Representative shall not previously have been advised and furnished with a copy or to which the Representative shall have reasonably objected in writing or which is not in compliance with the Rules and Regulations.

(b) The Company will (i) not make any offer relating to the Shares that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405 under the Act) required to be filed by the Company with the Commission under Rule 433 under the Act unless the Representative approves its use in writing prior to first use (each, a “Permitted Free Writing Prospectus”); provided that the prior written consent of the Representative hereto shall be deemed to have been given in respect of the Issuer Free Writing Prospectus(es) included on Schedule III hereto, (ii) treat each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, (iii) comply with the requirements of Rules 164 and 433 under the Act applicable to any Issuer Free Writing Prospectus, including the requirements

relating to timely filing with the Commission, legending and record keeping and (iv) 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) under the Act a free writing prospectus prepared by or on behalf of such Underwriter that such Underwriter otherwise would not have been required to file thereunder. The Company will satisfy the conditions in Rule 433 under the Act to avoid a requirement to file with the Commission any electronic road show.

(c) The Company will advise the Representative promptly (i) when the Registration Statement or any post-effective amendment thereto shall have become effective, (ii) of receipt of any comments from the Commission, (iii) when any supplement to the Prospectus or any Issuer Free Writing Prospectus or any amendment to the Prospectus has been filed, (iv) of any request of the Commission for amendment of the Registration Statement or for supplement to the General Disclosure Package or the Prospectus or for any additional information, (v) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any order preventing or suspending the use of the Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus, or of the institution of any proceedings for that purpose or pursuant to Section 8A of the Act, (vi) of the occurrence of any event within the Prospectus Delivery Period as a result of which the Prospectus, the General Disclosure Package or any Issuer Free Writing Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus, the General Disclosure Package or any such Issuer Free Writing Prospectus is delivered to a purchaser, not misleading, and (vii) of the receipt by the Company within the Prospectus Delivery Period of any written notice with respect to any suspension of the qualification of the Shares for offer and sale in any jurisdiction or the initiation or, to the knowledge of the Company, threatening of any proceeding for such purpose. The Company will use its best efforts to prevent the issuance of any order referred to in clause (v) or (vii) of this paragraph and to obtain as soon as possible the lifting thereof, if issued.

(d) The Company will cooperate with the Representative in endeavoring to qualify the Shares for sale under the securities laws of such jurisdictions as the Representative may reasonably have designated in writing and will make such applications, file such documents, and furnish such information as may be reasonably required for that purpose; provided that the Company shall not be required to (x) qualify as a foreign corporation, (y) file a general consent to service of process in any jurisdiction where it is not now so qualified or required to file such a consent, or (z) subject itself to taxation in any such jurisdiction if it is not otherwise so subject. The Company will, from time to time, prepare and file such statements, reports, and other documents, as are or may be required to continue such qualifications in effect for so long a period as the Representative may reasonably request for distribution of the Shares.

(e) The Company will deliver to, or upon the order of, the Representative, from time to time, as many copies of the Preliminary Prospectus as the Representative may reasonably request. The Company will deliver to, or upon the order of, the Representative, from time to time, as many copies of any Issuer Free Writing Prospectus as the Representative may reasonably request. The Company will deliver to, or upon the order of, the Representative during the period when

delivery of a Prospectus (or, in lieu thereof, the notice referred to under Rule 173(a) under the Act) is required under the Act, as many copies of the Prospectus in final form, or as thereafter amended or supplemented, as the Representative may reasonably request. The Company will deliver to the Representative at or before the Closing Date, four signed copies of the Registration Statement and all amendments thereto including all exhibits filed therewith, and will deliver to the Representative such number of copies of the Registration Statement (including such number of copies of the exhibits filed therewith that may reasonably be requested), and of all amendments thereto, as the Representative may reasonably request.

(f) The Company will comply with the Act and the Rules and Regulations, and the Exchange Act and the rules and regulations of the Commission thereunder, so as to permit the completion of the distribution of the Shares as contemplated in this Agreement and the Prospectus. If during the period in which a prospectus (or, in lieu thereof, the notice referred to under Rule 173(a) under the Act) is required by law to be delivered by an Underwriter or dealer, 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 Prospectus in order to make the statements therein, in the light of the circumstances existing at the time the Prospectus is delivered to a purchaser, not misleading, or, if it is necessary at any time to amend or supplement the Prospectus to comply with any law, the Company promptly will prepare and file with the Commission an appropriate amendment to the Registration Statement or supplement to the Prospectus so that the Prospectus as so amended or supplemented will not, in the light of the circumstances when it is so delivered, be misleading, or so that the Prospectus will comply with applicable law.

(g) If the General Disclosure Package is being used to solicit offers to buy the Shares at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition shall exist as a result of which, in the judgment of the Company or in the reasonable opinion of the Representative, it becomes necessary to amend or supplement the General Disclosure Package in order to make the statements therein, in the light of the circumstances, not misleading, or to make the statements therein not conflict with the information contained in the Registration Statement then on file, 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 prepare, file with the Commission (if required) and furnish to the Underwriters an appropriate amendment or supplement to the General Disclosure Package so that the General Disclosure Package as so amended or supplemented will not, in the light of the circumstances, be misleading or conflict with the Registration Statement then on file, or so that the General Disclosure Package will comply with applicable law.

(h) The Company will make generally available to its security holders, as soon as it is practicable to do so, but in any event not later than 15 months after the effective date of the Registration Statement, an earnings statement (which need not be audited) in reasonable detail, covering a period of at least 12 consecutive months beginning after the effective date of the Registration Statement, which earnings statement shall satisfy the requirements of Section 11(a) of the Act and Rule 158 under the Act and will advise the Representative in writing when such statement has been so made available.

(i) If, prior to the Closing Date, any unaudited interim financial statements of the Company for any period subsequent to the period covered by the most recent financial statements appearing in the Registration Statement, the General Disclosure Package and the Prospectus are prepared by or are available to the Company, the Company will furnish a copy of such unaudited interim financial statements of the Company to the Representative as soon as they have been so prepared or are made available to the Company.

(j) No offering, pledge, sale, contract to sell, short sale or other disposition of any shares of Common Stock of the Company or other securities convertible into or exchangeable or exercisable for shares of Common Stock or derivative of Common Stock (or agreement for such) will be made for a period of 180 days after the date of the Prospectus, directly or indirectly, by the Company otherwise than hereunder or with the prior written consent of the Representative. Notwithstanding the foregoing, if (1) during the last 17 days of the 180-day restricted period, the Company issues an earnings release or material news or a material event relating to the Company occurs, or (2) prior to the expiration of the 180-day restricted period, the Company announces that it will release earnings results during the 16-day period following the last day of the 180-day restricted period, then in each case the restrictions imposed by this Agreement shall continue to apply until the expiration of the 18-day period beginning on the date of the release of the earnings results or the occurrence of material news or a material event relating to the Company, as the case may be, unless the Representative waives, in writing, such extension. The Company shall promptly notify the Representative of any earnings release, news or event that may give rise to an extension of the initial 180-day restricted period.

The restrictions contained in the preceding paragraph shall not apply to (a) the sale and issuance of the Shares to be sold hereunder; (b) the issuance of Common Stock upon conversion or exchange of outstanding Preferred Stock, outstanding convertible promissory notes and other outstanding securities as disclosed in the Prospectus; (c) the issuance of Shares of Common Stock upon exercise of outstanding warrants, stock options or other derivative securities disclosed in the Prospectus; (d) the issuance of shares of, or options to purchase shares of, Common Stock to employees, officers, directors, advisors or consultants of the Company pursuant to the Company’s stock option and employee benefit plans (including employee stock purchase plans) disclosed in the Prospectus; (e) the filing of a registration statement on Form S-8 for the registration of shares of Common Stock issued pursuant to the Company’s stock option and employee benefit plans (including employee stock purchase plans) disclosed in the Prospectus; or (f) the issuance of up to an aggregate of 5% of the shares of Common Stock to be outstanding immediately following the sale and issuance of the Shares pursuant to this Agreement in connection with a strategic partnership, joint venture, collaboration, debt financing or the acquisition or license of any business products or technology; provided that prior to any issuance pursuant to clauses (b), (c), (d) or (f) of this paragraph, the Company shall cause each recipient of such shares or options to execute and deliver to you a letter or letters, substantially in the form of the Lockup Agreement as defined below.

(k) The Company will use its best efforts to list the Shares for quotation on the NASDAQ Global Market.

(l) The Company has caused each officer, director and specific shareholders of the Company to execute and deliver to you, on or prior to the date of this agreement, a letter or letters, substantially in the form attached hereto as Exhibit B (the “Lockup Agreement”). If the Representative, in its sole discretion, agrees to release or waive the restrictions set forth in a Lockup Agreement for an officer or director of the Company and provides the Company with notice of the impending release or waiver, substantially in the form attached as Exhibit C hereto, at least three business days before the effective date of the release or waiver, the Company agrees to announce the impending release or waiver by a press release substantially in the form of Exhibit D hereto through a major news service at least two business days before the effective date of the release or waiver.

(m) The Company shall apply the net proceeds of its sale of the Shares as set forth in the Registration Statement, the General Disclosure Package and the Prospectus and shall file such reports with the Commission with respect to the sale of the Shares and the application of the proceeds therefrom as may be required in accordance with Rule 463 under the Act.

(n) The Company shall not invest, or otherwise use the proceeds received by the Company from its sale of the Shares in such a manner as would require the Company or any of the Subsidiaries to register as an investment company under the 1940 Act.

(o) The Company will maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar for the Common Stock.

(p) The Company will not take, directly or indirectly, any action designed to cause or result in, or that has constituted or might reasonably be expected to constitute, the stabilization or manipulation of the price of any securities of the Company.

(q) The Company will promptly notify the Representatives if the Company ceases to be an Emerging Growth Company at any time prior to the later of (a) completion of the distribution of the Securities within the meaning of the Securities Act and (b) completion of the 180-day restricted period referred to in Section 4(j) hereof.

5. COSTS AND EXPENSES.

The Company will pay all costs, expenses and fees incident to the performance of the obligations of the Company under this Agreement, including, without limiting the generality of the foregoing, the following: (i) accounting fees of the Company; (ii) the fees and disbursements of counsel for the Company; (iii) all costs and expenses related to the transfer and delivery of the Shares to the Underwriters, including any transfer or other taxes payable thereon; (iv) any road show expenses; (v) the cost of printing and delivering to, or as requested by, the Underwriters

copies of the Registration Statement, the Preliminary Prospectus, the Issuer Free Writing Prospectuses, the Prospectus, this Agreement, the listing application, any Blue Sky survey, and in each case, any supplements or amendments thereto; (vi) the filing fees of the Commission; (vii) the filing fees and expenses (including the reasonable legal fees and disbursements of counsel for the Underwriters) incident to securing any required review by FINRA of the terms of the sale of the Shares; (viii) all expenses and application fees related to the listing of the Shares on of the NASDAQ Global Market; (ix) the cost of printing certificates, if any, representing the Shares; (x) the costs and charges of any transfer agent, registrar or depositary; (xi) the costs and expenses (including without limitation any damages or other amounts payable in connection with legal or contractual liability) associated with the reforming of any contracts for sale of the Shares made by the Underwriters caused by a breach of the representation in Section 1(b) hereof); and (xii) and the expenses, including the reasonable fees and disbursements of counsel for the Underwriters, incurred in connection with the qualification of the Shares under foreign or state securities or Blue Sky laws. The Company shall not, however, be required to pay for any of the Underwriter’s expenses (other than those related to qualification under FINRA regulation and state securities or Blue Sky laws in accordance with clauses (vii) and (xii) above) except that, if this Agreement shall not be consummated because the conditions in Section 6 hereof are not satisfied, or because this Agreement is terminated by the Company pursuant to Section 8 or by the Representative pursuant to Section 10(a)(i), Section 10(a)(iv) or Section 10(a)(vi) hereof, or by reason of any failure, refusal or inability on the part of the Company to perform any undertaking or satisfy any condition of this Agreement or to comply with any of the terms hereof on its part to be performed, unless such failure, refusal or inability is due primarily to the default or omission of any Underwriter, the Company shall reimburse the several Underwriters for reasonable out-of-pocket expenses, including fees and disbursements of counsel, reasonably incurred in connection with investigating, marketing and proposing to market the Shares or in contemplation of performing their obligations hereunder; but the Company shall not in any event be liable to any of the several Underwriters for damages on account of loss of anticipated profits from the sale by them of the Shares.

6. CONDITIONS OF OBLIGATIONS OF THE UNDERWRITERS.

The several obligations of the Underwriters to purchase the Firm Shares on the Closing Date and the Option Shares, if any, on the Option Closing Date are subject to the accuracy, as of the Applicable Time, the Closing Date or the Option Closing Date, as the case may be, of the representations and warranties of the Company contained herein, and to the performance by the Company of its covenants and obligations hereunder and to the following additional conditions:

(a) The Registration Statement and all post-effective amendments thereto shall have become effective and the Prospectus and each Issuer Free Writing Prospectus required shall have been filed as required by Rules 424, 430A, 430B, 430C or 433 under the Act, as applicable, within the time period prescribed by, and in compliance with, the Rules and Regulations, and any request of the Commission for additional information (to be included in the Registration Statement or otherwise) shall have been disclosed to the Representative and complied with to its reasonable satisfaction. No stop order suspending the effectiveness of the Registration Statement, as amended from time to time, shall have been issued and no proceedings for that purpose or pursuant to

Section 8A under the Act shall have been taken or, to the knowledge of the Company, shall be contemplated or threatened by the Commission and no injunction, restraining order or order of any nature by a federal or state court of competent jurisdiction shall have been issued as of the Closing Date which would prevent the issuance of the Shares.

(b) The Representative shall have received on the Closing Date or the Option Closing Date, as the case may be, the opinion and negative assurance letter of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., counsel for the Company, dated the Closing Date or the Option Closing Date, as the case may be, addressed to the Underwriters (and stating that it may be relied upon by counsel to the Underwriters) substantially in the form of Exhibit E hereto.

(c) The Representative shall have received on the Closing Date or the Option Closing Date, as the case may be, the opinion of Wilmer Cutler Pickering Hale and Dorr LLP, outside intellectual property counsel for the Company, dated the Closing Date or the Option Closing Date, as the case may be, in the form attached hereto as Exhibit F.

(d) The Representative shall have received from Goodwin Procter LLP, counsel for the Underwriters, an opinion and negative assurance letter, each dated the Closing Date or the Option Closing Date, as the case may be, in a form satisfactory to the Representative.

(e) The Representative shall have received, on each of the date hereof, the Closing Date and, if applicable, the Option Closing Date, a letter dated the date hereof, the Closing Date or the Option Closing Date, as the case may be, in form and substance satisfactory to the Representative, of PricewaterhouseCoopers LLP confirming that they are an independent registered public accounting firm with respect to the Company and the Subsidiaries within the meaning of the Act and the applicable Rules and Regulations and the PCAOB and stating that in their opinion the financial statements and schedules examined by them and included in the Registration Statement, the General Disclosure Package and the Prospectus comply in form in all material respects with the applicable accounting requirements of the Act and the related Rules and Regulations; and containing such other statements and information as is ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial and statistical information contained in the Registration Statement, the General Disclosure Package and the Prospectus.

(f) The Representative shall have received on the Closing Date and, if applicable, the Option Closing Date, as the case may be, a certificate or certificates of the Chief Executive Officer and the Chief Financial Officer of the Company to the effect that, as of the Closing Date or the Option Closing Date, as the case may be, each of them severally represents as follows:

(i) The Registration Statement has become effective under the Act and no stop order suspending the effectiveness of the Registration Statement or no order preventing or suspending the use of the Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus has been issued, and no proceedings for such purpose or pursuant to Section 8A of the Act have been taken or are, to his knowledge, contemplated or threatened by the Commission;

(ii) The representations and warranties of the Company contained in Section 1 hereof are true and correct as of the Closing Date or the Option Closing Date, as the case may be;

(iii) All filings required to have been made pursuant to Rules 424, 430A, 430B or 430C under the Act have been made as and when required by such rules;

(iv) He has carefully examined the General Disclosure Package and any individual Limited Use Free Writing Prospectus, if any are used in connection with the offering contemplated herein, and, in his opinion, as of the Applicable Time, the statements contained in the General Disclosure Package and any such individual Limited Use Free Writing Prospectus did not contain any untrue statement of a material fact, and such General Disclosure Package and any individual Limited Use Free Writing Prospectus, when considered together with the General Disclosure Package, did not omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that such certificate or certificates need not refer to the information provided by the Representative on behalf of the Underwriters, as described in Section 12 of this Agreement;

(v) He has carefully examined the Registration Statement and, in his opinion, as of the effective date of the Registration Statement, the Registration Statement and any amendments thereto did not contain any untrue statement of a material fact and did not omit to state a material fact necessary in order to make the statements therein not misleading, and since the effective date of the Registration Statement, no event has occurred which should have been set forth in a supplement to or an amendment of the Prospectus which has not been so set forth in such supplement or amendment; provided, however, that such certificate or certificates need not refer to the information provided by the Representative on behalf of the Underwriters, as described in Section 12 of this Agreement;

(vi) He has carefully examined the Prospectus and, in his opinion, as of its date and the Closing Date or the Option Closing Date, as the case may be, the Prospectus and any amendments and supplements thereto did not contain 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 under which they were made, not misleading; and

(vii) Since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and Prospectus, there has not been any material adverse change or any development involving a prospective material adverse change in or affecting the business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company and the Subsidiaries taken as a whole, whether or not arising in the ordinary course of business.

(g) The Company shall have furnished to the Representative such further certificates and documents confirming the representations and warranties, covenants and conditions contained herein and related matters as the Representative may reasonably have requested.

(h) The Firm Shares and Option Shares, if any, have been approved for quotation upon notice of issuance on the NASDAQ Global Market.

(i) The Lockup Agreements described in Section 4(l) hereof are in full force and effect.

The opinions and certificates mentioned in this Agreement shall be deemed to be in compliance with the provisions hereof only if, , in the exercise of their reasonable judgment, they are in all material respects satisfactory to the Representative and to Goodwin Procter LLP, counsel for the Underwriters.

If any of the conditions hereinabove provided for in this Section 6 shall not have been fulfilled when and as required by this Agreement to be fulfilled, the obligations of the Underwriters hereunder may be terminated by the Representative by notifying the Company of such termination in writing or by telegram at or prior to the Closing Date or the Option Closing Date, as the case may be.

In such event, the Company and the Underwriters shall not be under any obligation to each other (except to the extent provided in Sections 5 and 7 hereof).

Notwithstanding any of the foregoing, the obligations of the Company to sell and deliver the portion of the Shares required to be delivered as and when specified in this Agreement are subject to the conditions that at the Closing Date and any Option Closing Date, as the case may be, no stop order suspending the effectiveness of the Registration Statement shall have been issued and in effect or proceedings therefor initiated or threatened.

7. INDEMNIFICATION.

(a) The Company agrees:

(i) to indemnify and hold harmless each Underwriter, the directors and officers of each Underwriter and each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Act or Section 20 of the Exchange Act, against any losses, claims, damages or liabilities to which such Underwriter or any such controlling person may become subject under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or any amendment or supplement thereto, (ii) with respect to the Registration Statement or any amendment or supplement thereto, the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading or (iii) with respect to the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or any amendment or supplement thereto, the omission or alleged omission to state therein a material fact required to be stated therein

or necessary to make the statements therein not misleading in the light of the circumstances under which they were made; provided, however, that the Company will not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement, or omission or alleged omission made in the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus, or such amendment or supplement, in reliance upon and in conformity with written information furnished to the Company by or through the Representative specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 12 hereof; and

(ii) to reimburse each Underwriter, each Underwriters’ directors and officers, and each such controlling person upon demand for any legal or other out-of-pocket expenses reasonably incurred by such Underwriter or such controlling person in connection with investigating or defending any such loss, claim, damage or liability, action or proceeding or in responding to a subpoena or governmental inquiry related to the offering of the Shares, whether or not such Underwriter or controlling person is a party to any action or proceeding. In the event that it is finally judicially determined that the Underwriters were not entitled to receive payments for legal and other expenses pursuant to this subparagraph, the Underwriters will promptly return all sums that had been advanced pursuant hereto.

(b) Each Underwriter severally and not jointly will indemnify and hold harmless the Company, each of its directors, each of its officers who have signed the Registration Statement, and each person, if any, who controls the Company within the meaning of the Act, against any losses, claims, damages or liabilities to which the Company or any such director, officer, or controlling person may become subject under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or any amendment or supplement thereto, (ii) with respect to the Registration Statement or any amendment or supplement thereto, the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading or (iii) with respect to the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or any amendment or supplement thereto, the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances under which they were made; and will reimburse any legal or other expenses reasonably incurred by the Company or any such director, officer, or controlling person in connection with investigating or defending any such loss, claim, damage, liability, action or proceeding; provided, however, that each Underwriter will be liable in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission has been made in the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or such amendment or supplement, in reliance upon and in conformity with written information furnished to the Company by or through the Representative specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 12 hereof. This indemnity agreement will be in addition to any liability which such Underwriter may otherwise have.

(c) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to this Section 7, such person (the “indemnified party”) shall promptly notify the person against whom such indemnity may be sought (the “indemnifying party”) in writing. No indemnification provided for in Section 7(a) or (b) shall be available to any party who shall fail to give notice as provided in this Section 7(c) if the party to whom notice was not given was unaware of the proceeding to which such notice would have related and was materially prejudiced by the failure to give such notice, but the failure to give such notice shall not relieve the indemnifying party or parties from any liability which it or they may have to the indemnified party for contribution or otherwise than on account of the provisions of Section 7(a) or (b). In case any such proceeding shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel satisfactory to such indemnified party and shall pay as incurred the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel at its own expense. Notwithstanding the foregoing, the indemnifying party shall pay as incurred (or within 30 days of presentation) the fees and expenses of the counsel retained by the indemnified party in the event (i) the indemnifying party and the indemnified party shall have mutually agreed to the retention of such counsel, (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them or (iii) the indemnifying party shall have failed to assume the defense and employ counsel acceptable to the indemnified party within a reasonable period of time after notice of commencement of the action. Such firm shall be designated in writing by you in the case of parties indemnified pursuant to Section 7(a) and by the Company in the case of parties indemnified pursuant to Section 7(b) hereof. The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. In addition, the indemnifying party will not, without the prior written consent of the indemnified party, settle or compromise or consent to the entry of any judgment in any pending or threatened claim, action or proceeding of which indemnification may be sought hereunder (whether or not any indemnified party is an actual or potential party to such claim, action or proceeding) unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such claim, action or proceeding and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d) To the extent the indemnification provided for in this Section 7 is unavailable to or insufficient to hold harmless an indemnified party under Section 7(a) or (b) above in respect of any losses, claims, damages or liabilities (or actions or proceedings in respect thereof) referred to

therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (or actions or proceedings in respect thereof) 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 from the offering of the Shares. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities (or actions or proceedings in respect thereof), as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same proportion as the net proceeds from the offering (before deducting expenses) received by the Company bear to the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or the Underwriters on the other and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this Section 7(d) were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7(d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions or proceedings in respect thereof) referred to above in this Section 7(d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this subsection (d), (i) no Underwriter shall be required to contribute any amount in excess of the underwriting discounts and commissions applicable to the Shares purchased by such Underwriter, and (ii) no person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this Section 7(d) to contribute are several in proportion to their respective underwriting obligations and not joint.

(e) In any proceeding relating to the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, the Prospectus or any supplement or amendment thereto, each party against whom contribution may be sought under this Section 7 hereby consents to the exclusive jurisdiction of (i) the federal courts of the United States of America located in the City and County of New York, Borough of Manhattan and (ii) the courts of the State of New York located in the City and County of New York, Borough of Manhattan (collectively, the “Specified Courts”), agrees that process issuing from such courts may be served upon it by any other contributing party and consents to the service of such process and agrees that any other contributing party may join it as an additional defendant in any such proceeding in which such other contributing party is a party.

(f) Any losses, claims, damages, liabilities or expenses for which an indemnified party is entitled to indemnification or contribution under this Section 7 shall be paid by the indemnifying party to the indemnified party as such losses, claims, damages, liabilities or expenses are incurred. The indemnity and contribution agreements contained in this Section 7 and the representations and warranties of the Company set forth in this Agreement shall remain operative and in full force and effect, regardless of (i) any investigation made by or on behalf of any Underwriter, its directors or officers or any person controlling any Underwriter, the Company, its directors or officers or any persons controlling the Company, (ii) acceptance of any Shares and payment therefor hereunder, and (iii) any termination of this Agreement. A successor to any Underwriter, its directors or officers or any person controlling any Underwriter, or to the Company, its directors or officers, or any person controlling the Company, shall be entitled to the benefits of the indemnity, contribution and reimbursement agreements contained in this Section 7.

8. DEFAULT BY UNDERWRITERS.

If on the Closing Date or the Option Closing Date, as the case may be, any Underwriter shall fail to purchase and pay for the portion of the Shares which such Underwriter has agreed to purchase and pay for on such date (otherwise than by reason of any default on the part of the Company), you, as Representative of the Underwriters, shall use your reasonable efforts to procure within 36 hours thereafter one or more of the other Underwriters, or any others, to purchase from the Company such amounts as may be agreed upon and upon the terms set forth herein, the Shares which the defaulting Underwriter or Underwriters failed to purchase. If during such 36 hours you, as such Representative, shall not have procured such other Underwriters, or any others, to purchase the Shares agreed to be purchased by the defaulting Underwriter or Underwriters, then (a) if the aggregate number of shares with respect to which such default shall occur does not exceed 10% of the Shares to be purchased on the Closing Date or the Option Closing Date, as the case may be, the other Underwriters shall be obligated, severally, in proportion to the respective numbers of Shares which they are obligated to purchase hereunder, to purchase the Shares which such defaulting Underwriter or Underwriters failed to purchase, or (b) if the aggregate number of Shares with respect to which such default shall occur exceeds 10% of the Shares to be purchased on the Closing Date or the Option Closing Date, as the case may be, the Company or you as the Representative of the Underwriters will have the right, by written notice given within the next 36-hour period to the parties to this Agreement, to terminate this Agreement without liability on the part of the non-defaulting Underwriters or of the Company except to the extent provided in Sections 5 and 7 hereof. In the event of a default by any Underwriter or Underwriters, as set forth in this Section 8, the Closing Date or Option Closing Date, as the case may be, may be postponed for such period, not exceeding seven days, as you, as Representative, may determine in order that the required changes in the Registration Statement, the General Disclosure Package or in the Prospectus or in any other documents or arrangements may be effected. The term “Underwriter” includes any person substituted for a defaulting Underwriter. Any action taken under this Section 8 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

9. NOTICES.

All communications hereunder shall be in writing and, except as otherwise provided herein, will be mailed, delivered, telecopied or telegraphed and confirmed as follows:

if to the Underwriters, to Deutsche Bank Securities Inc., 60 Wall Street, 4th Floor, New York, New York 10005, Attention: Equity Capital Markets – Syndicate Desk, fax: (212) ###-###-####, with a copy to Deutsche Bank Securities Inc., 60 Wall Street, 36^th Floor, New York, New York 10005, Attention: General Counsel, fax: (212) ###-###-####; and

if to the Company, to Rib-X Pharmaceuticals, Inc., 300 George Street, Suite 301, New Haven, Connecticut 06511, Attention: Robert Conerly, Chief Financial Officer, with a copy to, Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., One Financial Center, Boston, Massachusetts 02111, Attention: Jonathan L Kravetz, Esq., fax: (617) ###-###-####.

10. TERMINATION.

This Agreement may be terminated by you by notice to the Company: (a) at any time prior to the Closing Date or any Option Closing Date (if different from the Closing Date and then only as to Option Shares) if any of the following has occurred: (i) since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, any material adverse change or any development involving a prospective material adverse change in or affecting the earnings, business, management, properties, assets, rights, operations, condition (financial or otherwise) or prospects of the Company and the Subsidiaries taken as a whole, whether or not arising in the ordinary course of business; (ii) any outbreak or escalation of hostilities or declaration of war or national emergency or other national or international calamity or crisis (including, without limitation, an act of terrorism) or change in economic or political conditions if the effect of such outbreak, escalation, declaration, emergency, calamity, crisis or change on the financial markets of the United States would, in your judgment, materially impair the investment quality of the Shares; (iii) suspension of trading in securities generally on the New York Stock Exchange, the American Stock Exchange or the NASDAQ Global Market or limitation on prices (other than limitations on hours or numbers of days of trading) for securities on any such exchange; (iv) the enactment, publication, decree or other promulgation of any statute, regulation, rule or order of any court or other governmental authority which in your opinion materially and adversely affects or may materially and adversely affect the business or operations of the Company; (v) the declaration of a banking moratorium by the United States or New York State authorities; or (vi) the suspension of trading of the Company’s common stock by the NASDAQ Global Market, the Commission or any other governmental authority; or (vii) the taking of any action by any governmental body or agency in respect of its monetary or fiscal affairs which in your opinion has a material adverse effect on the securities markets in the United States; or

(b) as provided in Sections 6 and 8 of this Agreement.

11. SUCCESSORS.

This Agreement has been and is made solely for the benefit of the Underwriters and the Company and their respective successors, executors, administrators, heirs and assigns, and the officers, directors and controlling persons referred to herein, and no other person will have any right or obligation hereunder. No purchaser of any of the Shares from any Underwriter shall be deemed a successor or assign merely because of such purchase.

12. INFORMATION PROVIDED BY UNDERWRITERS.

The Company and the Underwriters acknowledge and agree that the only information furnished or to be furnished by any Underwriter to the Company for inclusion in the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus consists of the following information: (i) the information regarding concessions and reallowances set forth in the third paragraph under the caption “Underwriting” in the Prospectus and (ii) the information set forth in the eleventh through eighteenth paragraphs under the caption “Underwriting” in the Prospectus.

13. MISCELLANEOUS.

The reimbursement, indemnification and contribution agreements contained in this Agreement and the representations, warranties and covenants in this Agreement shall remain in full force and effect regardless of (a) any termination of this Agreement, (b) any investigation made by or on behalf of any Underwriter or controlling person thereof, or by or on behalf of the Company or its directors or officers and (c) delivery of and payment for the Shares under this Agreement.

The Company acknowledges and agrees that each Underwriter in providing investment banking services to the Company in connection with the offering, including in acting pursuant to the terms of this Agreement, has acted and is acting as an independent contractor and not as a fiduciary and the Company does not intend such Underwriter to act in any capacity other than as an independent contractor, including as a fiduciary or in any other position of higher trust. Additionally, neither the Representative nor any other Underwriter is advising the Company or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company shall consult with their own advisors concerning such matters and shall be responsible for making their own independent investigation and appraisal of the transactions contemplated hereby, and the Underwriters shall have no responsibility or liability to the Company with respect thereto. Any review by the Underwriters of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company.

This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

This Agreement shall be governed by, and construed in accordance with, the law of the State of New York, including, without limitation, Section 5-1401 of the New York General Obligations Law.

Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“Related Proceedings”) shall be instituted in the Specified Courts, and each party irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any such court (a “Related Judgment”), as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum.

The Underwriters, on the one hand, and the Company (on its own behalf and, to the extent permitted by law, on behalf of its stockholders), on the other hand, waive any right to trial by jury in any action, claim, suit or proceeding with respect to your engagement as underwriter or your role in connection herewith.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to us the enclosed duplicates hereof, whereupon it will become a binding agreement among the Company and the several Underwriters in accordance with its terms.

[Remainder of Page Intentionally Left Blank]


Very truly yours,

RIB-X PHARMACEUTICALS, INC.

By
Name:
Title:

The foregoing Underwriting Agreement

is hereby confirmed and accepted as

of the date first above written.

DEUTSCHE BANK SECURITIES INC.

As Representative of the several

Underwriters listed on Schedule I hereto

By: Deutsche Bank Securities Inc.


By:
Name:
Title:

By:
Name:
Title:

SCHEDULE I

SCHEDULE OF UNDERWRITERS


Underwriter	Number of Firm Shares to be Purchased	Number of Option Shares to be Purchased
Deutsche Bank Securities Inc.
William Blair & Company, L.L.C.
Lazard Capital Markets LLC
Needham & Company, LLC

Total

SCHEDULE II

Pricing Terms

SCHEDULE III

Schedule of Issuer Free Writing Prospectuses included in the General Disclosure Package

EXHIBIT A

LIST OF SUBSIDIARIES

Rib-X Therapeutics Limited, a United Kingdom entity

EXHIBIT B

LOCK-UP AGREEMENT

, 20

Rib-X Pharmaceuticals, Inc.

Deutsche Bank Securities Inc.

60 Wall Street, 4^th Floor

New York, New York 10005

As Representative of the

Several Underwriters

Ladies and Gentlemen:

The undersigned understands that Deutsche Bank Securities Inc., as representative (the “Representative”) of the several underwriters (the “Underwriters”), proposes to enter into an Underwriting Agreement (the “Underwriting Agreement”) with Rib-X Pharmaceuticals, Inc., a Delaware corporation (the “Company”), providing for the public offering by the Underwriters, including the Representative, of common stock, par value $0.001 (the “Common Stock”), of the Company (the “Public Offering”) pursuant to a registration statement on Form S-1 (the “Registration Statement”) to be filed with the Securities and Exchange Commission (the “SEC”).

To induce the Underwriters that may participate in the Public Offering to continue their efforts in connection with the Public Offering, the undersigned agrees that, without the prior written consent of the Representative on behalf of the Underwriters, the undersigned will not, directly or indirectly, offer, sell, pledge, contract to sell (including any short sale), grant any option to purchase or otherwise dispose of any shares of Common Stock (including, without limitation, shares of Common Stock of the Company which may be deemed to be beneficially owned by the undersigned on the date hereof in accordance with the rules and regulations of the SEC, shares of Common Stock which may be issued upon exercise of a stock option or warrant and any other security convertible into or exchangeable for Common Stock) or enter into any Hedging Transaction (as defined below) relating to the Common Stock (each of the foregoing referred to as a “Disposition”) during the period specified in the following paragraph (the “Lock-Up Period”). If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any Company-directed shares of Common Stock the undersigned may purchase in the Public Offering. The foregoing restriction is expressly intended to preclude the undersigned from engaging in any Hedging Transaction or other transaction which is designed to or reasonably expected to lead to or result in a Disposition during the Lock-Up Period even if the securities would be disposed of by someone other than the undersigned. “Hedging Transaction” means any short sale (whether or not against the box) or any

purchase, sale or grant of any right (including, without limitation, any put or call option) with respect to any security (other than a broad-based market basket or index) that includes, relates to or derives any significant part of its value from the Common Stock.

If the undersigned is an officer or director of the Company, (i) the Representative, on behalf of the Underwriters, 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 by the undersigned, the Representative, on behalf of the Underwriters, will notify the Company of the impending release or waiver, and (ii) the Company will agree in the Underwriting Agreement to announce the impending release or waiver of any such officer or director by press release through a major news service at least two business days before the effective date of the release or waiver. Any release or waiver granted by the Representative hereunder to any such officer or director shall only be effective two business days after the publication date of such press release. 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 initial Lock-Up Period will commence on the date hereof and continue until, and include, the date that is 180 days after the date of the final prospectus relating to the Public Offering (the “Initial Lock-Up Period”); provided, however, that if (1) during the last 17 days of the Initial Lock-Up Period, (A) the Company releases earnings results or (B) material news or a material event relating to the Company occurs, or (2) prior to the expiration of the Initial Lock-Up Period, the Company announces that it will release earnings results during the 16-day period following the last day of the Initial Lock-Up Period, then in each case the Lock-Up Period will be extended until the expiration of the 18-day period beginning on the date of the release of the earnings results or the occurrence of material news or a material event relating to the Company, as the case may be, unless the Representative waives, in writing, such extension.

Notwithstanding the foregoing, the undersigned may transfer (a) shares of Common Stock acquired in open market transactions by the undersigned after the completion of the Public Offering, (b) any or all of the shares of Common Stock or other Company securities with the prior written consent of the Representative on behalf of the Underwriters, (c) shares of Common Stock or other Company securities to the Company in a transaction exempt from Section 16(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) in connection with the payment of taxes due upon the exercise of options to purchase Common Stock or vesting of other Company securities pursuant to employee benefit plans as described in the Registration Statement, and (d) any or all of the shares of Common Stock or other Company securities if the transfer is by (i) bona fide gift or gifts, will, other testamentary document, or intestacy (ii) distribution to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned, (iii) distribution to limited partners, members, stockholders, other equity holders, or, if the undersigned is a trust, trust beneficiaries, in each case, of the undersigned, or (iv) if the undersigned is a corporation, distribution to any wholly-owned subsidiary of the undersigned; provided, however, that (A) in the case of a transfer pursuant to clause (d) above, it shall be a condition to the transfer that the transferee execute an agreement stating that the transferee is receiving and holding the

securities subject to the provisions of this Lock-Up Agreement and (B) in the case of a transfer pursuant to either clause (c) or clause (d) above, no filing under Section 16(a) of the Exchange Act reporting a reduction in beneficial ownership of shares of Common Stock shall be required or shall be voluntarily made during the Lock-Up Period. Notwithstanding anything to the contrary herein, (a) this Lock-Up Agreement shall not restrict the exercise of stock options granted pursuant to the Company’s equity incentive plans or of warrants described in the Registration Statement, provided that it shall apply to any of the undersigned’s Common Stock issued upon such exercise and (b) the undersigned shall be permitted to establish a contract, instruction or plan (a “10b5-1 Plan”) that complies with the requirements of Rule 10b5-1(c)(1) under the Exchange Act at any time during the Lock-Up Period; provided that, during the Lock-Up Period, (i) the undersigned shall not transfer any of the Common Stock or other Company securities under such 10b5-1 Plan and (ii) no public announcement or disclosure of entry into such 10b5-1 Plan is made or required to be made, including any filing with the SEC under Section 13 or Section 16 of the Exchange Act.

The undersigned agrees that the Company may, and that the undersigned will, (i) with respect to any shares of Common Stock or other Company securities for which the undersigned is the record holder, cause the transfer agent for the Company to note stop transfer instructions with respect to such securities on the transfer books and records of the Company and (ii) with respect to any shares of Common Stock or other Company securities for which the undersigned is the beneficial holder but not the record holder, cause the record holder of such securities to cause the transfer agent for the Company to note stop transfer instructions with respect to such securities on the transfer books and records of the Company.

In addition, the undersigned hereby waives any and all notice requirements and rights with respect to registration of securities pursuant to any agreement, understanding or otherwise setting forth the terms of any security of the Company held by the undersigned, including any registration rights agreement to which the undersigned and the Company may be party; provided that such waiver shall apply only to the proposed Public Offering, and any other action taken by the Company in connection with the proposed Public Offering.

The undersigned hereby agrees that, to the extent that the terms of this Lock-Up Agreement conflict with or are in any way inconsistent with any registration rights agreement to which the undersigned and the Company may be a party, this Lock-Up Agreement supersedes such registration rights agreement.

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Agreement. All authority herein conferred or agreed to be conferred shall survive the death or incapacity of the undersigned and any obligations of the undersigned shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

[SIGNATURE PAGE FOLLOWS]

The undersigned understands that the Company and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward the consummation of the Public Offering. This Lock-Up Agreement shall lapse and become null and void if (i) for any reason, the Underwriting Agreement is terminated prior to the closing of the Public Offering, (ii) the closing of the Public Offering has not occurred prior to September 30, 2012 or (iii) the date of filing by the Company with the SEC of a notice of withdrawal of the Registration Statement pursuant to Rule 477 of the Securities Act of 1933, as amended. This Lock-Up Agreement shall be governed by, and construed in accordance with, the laws of the State of New York without regard to the conflict of laws principles thereof.

If an individual, please sign here:

Signature:

Print Name:

If a corporation, a limited partnership or other legal entity, please sign here:


Legal Name:

By::
Name:
Title:

EXHIBIT C

FORM OF WAIVER

[Letterhead of DBSI]

Rib-X Pharmaceuticals, Inc.

Public Offering of Common Stock

[Date]

[Name and Address of

Officer or Director

Requesting Waiver]

Dear Mr./Ms. [Name]:

This letter is being delivered to you in connection with the offering by Rib-X Pharmaceuticals, Inc. (the “Company”) of [ ] shares of common stock, $0.001 par value (the “Common Stock”), of the Company and the lock-up letter dated [ ], 20[ ] (the “Lock-up Letter”), executed by you in connection with such offering, and your request for a [waiver] [release] dated [ ], 20[ ] , with respect to [ ] shares of Common Stock (the “Shares”).

Deutsche Bank Securities Inc. hereby agrees to [waive] [release] the transfer restrictions set forth in the Lock-up Letter, but only with respect to the Shares, effective [ ], 20[ ]; provided, however, that such [waiver] [release] is conditioned on the Company announcing the impending [waiver] [release] by press release through a major news service at least two business days before effectiveness of such [waiver] [release]. This letter will serve as notice to the Company of the impending [waiver] [release].

Except as expressly [waived] [released] hereby, the Lock-up Letter shall remain in full force and effect.


		Yours very truly,
		Deutsche Bank Securities Inc.

		By:
		Name:
		Title:

		By:
		Name:
		Title:

cc: Company

EXHIBIT D

FORM OF PRESS RELEASE

Rib-X Pharmaceuticals, Inc.

[Date]

Rib-X Pharmaceuticals, Inc. (the “Company”) announced today that Deutsche Bank Securities Inc., the lead book-running manager in the Company’s recent public sale of shares of common stock, is [waiving] [releasing] a lock-up restriction with respect to shares of the Company’s common stock held by [certain officers or directors] [an officer or director] of the Company. The [waiver] [release] will take effect on , 20 , and the shares may be sold on or after such date.

This press release is not an offer for sale of the securities in the United States or in any other jurisdiction where such offer is prohibited, and such securities may not be offered or sold in the United States absent registration or an exemption from registration under the United States Securities Act of 1933, as amended.