UNDERWRITING AGREEMENT1

EXHIBIT 1.1

ProQR Therapeutics B.V.

[—] Ordinary Shares

UNDERWRITING AGREEMENT

Dated: [—], 2014

ProQR Therapeutics B.V.

[—] Ordinary Shares

UNDERWRITING AGREEMENT¹

[—], 2014

Leerink Partners LLC

Deutsche Bank Securities Inc.

As Representatives of the several Underwriters

c/o Leerink Partners LLC

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▇▇▇

c/o Deutsche Bank Securities Inc.

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Ladies and Gentlemen:

ProQR Therapeutics B.V., a Dutch private company with limited liability (the “Company”), confirms its agreement with Leerink Partners LLC (“Leerink”), Deutsche Bank Securities Inc. (“DB”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters,” which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom Leerink and DB are acting as representatives (the “Representatives”), with respect to (i) the sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective numbers of ordinary shares, nominal value €[—] per ordinary share, of the Company (“Ordinary Shares”) set forth in Schedule A hereto and (ii) the grant by the Company to the Underwriters, acting severally and not jointly, of the option described in Section 2(b) hereof to purchase all or any part of [—] additional Ordinary Shares. The aforesaid [—] Ordinary Shares (the “Initial Securities”) to be purchased by the Underwriters and all or any part of the [—] Ordinary Shares subject to the option described in Section 2(b) hereof (the “Option Securities”) are herein called, collectively, the “Securities.”

References in this Agreement to Securities being sold by the Company or purchased from the Company (and the corollary uses of those concepts) should be understood to refer to those Securities being issued or granted by the Company and subscribed for from the Company, respectively. Similarly, references in this Agreement to Securities being delivered should be understood to refer to those Securities being issued by the Company.

The Company understands that the Underwriters propose to make a public offering of the Securities (the “Offering”) as soon as the Representatives deem advisable after this Agreement has been executed and delivered in accordance with the Registration Statement (as defined below).

Prior to the delivery of the Securities under this Agreement, the conversion of ProQR Therapeutics B.V. into a Dutch public company with limited liability, whereby the Company will be renamed ProQR Therapeutics N.V., will be effected by execution of one or more notarial deeds.

The Company and the Underwriters agree that up to [—] shares of the Initial Securities to be purchased by the Underwriters (the “Reserved Securities”) shall be reserved for sale by the Underwriters to certain persons designated by the Company (the “Invitees”), as part of the distribution of the Securities by the Underwriters, subject to the terms of this Agreement, the applicable rules, regulations and interpretations of the Financial Industry Regulatory Authority, Inc. (“FINRA”) and all other applicable laws, rules and regulations. The Company solely determined, without any direct or indirect participation by the Underwriters, the Invitees who will purchase Reserved Securities (including the amount to be purchased by such persons) sold by the Underwriters. To the extent that such Reserved Securities are not orally confirmed to the Underwriters for purchase by Invitees by 8:00 A.M. (New York City time) on the first business day after the date of this Agreement, such Reserved Securities may be offered to the public as part of the Offering contemplated hereby.

The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form F-1 (No. 333- 198151), including the related preliminary prospectus or prospectuses, covering the registration of the sale of the Securities under the Securities Act of 1933, as amended (the “1933 Act”). Promptly after execution and delivery of this Agreement, the Company will prepare and file a prospectus in accordance with the provisions of Rule 430A (“Rule 430A”) of the rules and regulations of the Commission under the 1933 Act (the “1933 Act Regulations”) and Rule 424(b) (“Rule 424(b)”) of the 1933 Act Regulations. The information included in such prospectus that was omitted from such registration statement at the time it became effective but that is deemed to be part of such registration statement at the time it became effective pursuant to Rule 430A(b) is herein called the “Rule 430A Information.” Such registration statement, including the amendments thereto, the exhibits thereto and any schedules thereto at the time it became effective, and including the Rule 430A Information, is herein called the “Registration Statement.” Any registration statement filed pursuant to Rule 462(b) of the 1933 Act Regulations is herein called the “Rule 462(b) Registration Statement” and, after such filing, the term “Registration Statement” shall include the Rule 462(b) Registration Statement.

Each prospectus used prior to the effectiveness of the Registration Statement, and each prospectus that omitted the Rule 430A Information that was used after such effectiveness and prior to the execution and delivery of this Agreement is herein called a “preliminary prospectus.” The final prospectus, in the form first furnished to the Underwriters for use in connection with the Offering is herein called the “Prospectus.” For purposes of this Agreement, all references to the Registration Statement, any preliminary prospectus, the Prospectus or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the

Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system or any successor system (“▇▇▇▇▇”).

As used in this Agreement:

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

“Applicable Time” means [ :00 P.M./A.M.], New York City time, on September 17, 2014 or such other time as agreed by the Company and the Representatives.

“General Disclosure Package” means any Issuer General Use Free Writing Prospectuses issued at or prior to the Applicable Time, the preliminary prospectus that is distributed to investors prior to the Applicable Time and the information included on Schedule B-1 hereto, all considered together.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the 1933 Act Regulations (“Rule 433”), including without limitation any “free writing prospectus” (as defined in Rule 405 of the 1933 Act Regulations (“Rule 405”)) relating to the Securities 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) exempt from filing with the Commission pursuant to Rule 433(d)(5)(i) because it contains a description of the Securities 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).

“Issuer General Use Free Writing Prospectus” means any Issuer Free Writing Prospectus that is intended for general distribution to prospective investors (other than a “bona fide electronic road show,” as defined in Rule 433 (the “Bona Fide Electronic Road Show”)), as evidenced by its being specified in Schedule B-2 hereto.

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

“Testing-the-Waters Communication” means any oral or written communication with potential investors undertaken in reliance on Section 5(d) of the 1933 Act.

“Written Testing-the-Waters Communication” means any Testing-the-Waters Communication that is a written communication within the meaning of Rule 405 of the 1933 Act Regulations.

SECTION 1. Representations and Warranties

(a) Representations and Warranties by the Company. The Company represents and warrants to each Underwriter as of the date hereof, the Applicable Time, the Closing Time (as defined below) and any Date of Delivery (as defined below), and agrees with each Underwriter, as follows:

(i) Registration Statement and Prospectuses. Each of the Registration Statement and any amendment thereto has become effective under the 1933 Act. No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto has been issued under the 1933 Act, no order preventing or suspending the use of any preliminary prospectus or the Prospectus has been issued and no proceedings for any of those purposes have been instituted or are pending or, to the Company’s knowledge, threatened. The Company has complied in all material respects with each request (if any) from the Commission for additional information.

Each of the Registration Statement and any post-effective amendment thereto, at the time it became effective, complied in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations. Each preliminary prospectus, the Prospectus and any amendment or supplement thereto, at the time each was filed with the Commission, complied in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations. Each preliminary prospectus delivered to the Underwriters for use in connection with this Offering and the Prospectus was or will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

The Company is a “foreign private issuer” within the meaning of Rule 405 under the 1933 Act.

(ii) Accurate Disclosure. Neither the Registration Statement nor any post-effective amendment thereto, at its effective time, at the Closing Time or at any Date of Delivery, contained, contains or will contain an untrue statement of a material fact or omitted, omits or will omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. As of the Applicable Time, none of (A) the General Disclosure Package, (B) any individual Issuer Limited Use Free Writing Prospectus, when considered together with the General Disclosure Package, nor (C) any individual Written Testing-the-Waters Communication, when considered together with the General Disclosure Package, included, includes or will include an untrue statement of a material fact or omitted, omits 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. Neither the Prospectus nor any amendment or supplement thereto (including any prospectus wrapper), as of its issue date, at the time of any filing with the Commission pursuant to Rule 424(b), at the Closing Time or at any Date of Delivery, included, includes or will include an untrue statement of a material fact or omitted, omits 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.

The representations and warranties in this subsection shall not apply to statements in or omissions from the Registration Statement (or any amendment thereto), the General Disclosure Package or the Prospectus (or any amendment or supplement thereto, including any prospectus wrapper) made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use therein. For purposes of this Agreement, the only information so

furnished shall be the information in the first paragraph under the heading “Underwriting–Commissions and Discounts,” the information in the second, third and fourth paragraphs under the heading “Underwriting–Price Stabilization, Short Positions and Penalty Bids” and the information under the heading “Underwriting–Electronic Distribution,” in each case contained in the Prospectus (collectively, the “Underwriter Information”).

(iii) Issuer Free Writing Prospectuses. 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 Securities.

(iv) Testing-the-Waters Materials. The Company (A) has not engaged in any Testing-the-Waters Communication other than Testing-the-Waters Communications with the consent of the Representatives with entities that are qualified institutional buyers within the meaning of Rule 144A of the 1933 Act Regulations or institutions that are accredited investors within the meaning of Rule 501 of the 1933 Act Regulations and (B) has not authorized anyone other than the Representatives to engage in Testing-the-Waters Communications. The Company reconfirms that the Representatives have been authorized to act on its behalf in undertaking Testing-the-Waters Communications. The Company has not distributed any Written Testing-the-Waters Communications other than those listed on Schedule B-3 hereto.

(v) Company Not Ineligible Issuer. At the time of filing the Registration Statement and any post-effective amendment thereto, at the earliest time thereafter that the Company made a bona fide offer (within the meaning of Rule 164(h)(2) of the 1933 Act Regulations) of the Securities and at the date hereof, the Company was not and is not an “ineligible issuer,” as defined in Rule 405, without taking account of any determination by the Commission pursuant to Rule 405 that it is not necessary that the Company be considered an ineligible issuer.

(vi) Emerging Growth Company Status. From the time of the initial confidential submission of the Registration Statement to the Commission (or, if earlier, the first date on which the Company engaged directly or through any person authorized to act on its behalf in any Testing-the-Waters Communication) through the date hereof, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the 1933 Act (an “Emerging Growth Company”).

(vii) Independent Accountants. The accountants who certified the financial statements and supporting schedules, if any, included in the Registration Statement, the General Disclosure Package and the Prospectus are independent public accountants as required by the 1933 Act, the 1933 Act Regulations and the Public Company Accounting Oversight Board.

(viii) Financial Statements. The financial statements included in the Registration Statement, the General Disclosure Package and the Prospectus, together with the related schedules and notes, present fairly, the financial position of the Company at the dates indicated and the statement of operations, shareholders’ equity (eigen vermogen) and cash flows of the Company for the periods specified; said financial statements have been prepared in conformity with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”) applied on a consistent basis throughout the periods involved, except in the case of unaudited, interim financial statements, subject to normal year-end audit adjustments and the exclusion of certain footnotes. The supporting schedules, if any, present fairly in accordance with IFRS the information required to be stated therein. The selected financial data and the summary financial information included in the Registration Statement, the General Disclosure Package and the Prospectus present fairly, the information shown therein and have been compiled on a basis consistent with that of the audited financial statements included therein. Except as included therein, no historical or pro forma financial statements or supporting schedules are required to be included or incorporated by reference in the Registration Statement, the General Disclosure Package or the Prospectus under the 1933 Act or the 1933 Act Regulations.

(ix) No Material Adverse Change in Business. Except as otherwise stated therein, since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, (A) there has been no material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or prospects of the Company, whether or not arising in the ordinary course of business (a “Material Adverse Effect”), (B) there have been no transactions entered into by the Company, other than those in the ordinary course of business, which are material with respect to the Company, and (C) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its share capital.

(x) Good Standing of the Company. The Company has been duly incorporated and is validly existing as a private company with limited liability (besloten vennootschap met beperkte aansprakelijkheid) under the laws of The Netherlands and has the power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the General Disclosure Package and the Prospectus and to enter into and perform its obligations under this Agreement; and the Company is duly qualified to transact business and is in good standing (where such concept exists) in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not reasonably be expected to result in a Material Adverse Effect.

(xi) Capitalization. The authorized and issued share capital and outstanding shares in the capital of the Company are as set forth in the Registration Statement, the General Disclosure Package and the Prospectus in the column entitled “Actual” under the caption “Capitalization” (except for subsequent issuances, if any, pursuant to this Agreement, pursuant to reservations, agreements or employee benefit plans referred to in

the Registration Statement, the General Disclosure Package and the Prospectus or pursuant to the exercise of convertible securities or options referred to in the Registration Statement, the General Disclosure Package and the Prospectus). All of the ordinary shares in the capital of the Company existing as of the date of this Agreement have been duly authorized and validly issued and are fully paid. None of the outstanding shares in the capital of the Company were issued in violation of the preemptive or other similar rights of any shareholder of the Company. The Company has no subsidiaries.

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

(xiii) Authorization and Description of Securities. The Securities to be purchased by the Underwriters from the Company have been duly authorized for issuance and sale to the Underwriters pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued and fully paid; and the issuance of the Securities is not subject to the preemptive or other similar rights of any shareholder of the Company. The Ordinary Shares conform, in all material respects, to all statements relating thereto contained in the Registration Statement, the General Disclosure Package and the Prospectus and such description conforms, in all material respects, to the rights set forth in the instruments defining the same. No holder of Securities will be subject to personal liability by reason of being such a holder, except for being subject to pay up the Securities acquired by them in full.

(xiv) Registration Rights. There are no persons with registration rights or other similar rights to have any securities registered for sale pursuant to the Registration Statement or otherwise registered for sale or sold by the Company under the 1933 Act pursuant to this Agreement, other than those rights that have been disclosed in the Registration Statement, the General Disclosure Package and the Prospectus.

(xv) Absence of Violations, Defaults and Conflicts. The Company is not (A) in violation of its articles of association, (B) in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or other agreement or instrument to which the Company is a party or by which it may be bound or to which any of the properties or assets of the Company is subject (collectively, “Agreements and Instruments”), except, in the case of (B), for such defaults as would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect, or (C) in violation of any law, statute, rule, regulation, judgment, order, writ or decree of any arbitrator, court, governmental body, regulatory body, administrative agency or other authority, body or agency having jurisdiction over the Company or any of its respective properties, assets or operations (each, a “Governmental Entity”), except, in the case of (C), for such violations as would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect. The execution, delivery and performance of this Agreement and the consummation of the transactions contemplated herein and in the Registration Statement, the General Disclosure Package and the Prospectus (including the issuance and sale of the Securities and the use of the proceeds from the sale of the

Securities as described therein under the caption “Use of Proceeds”) and compliance by the Company with its obligations hereunder have been duly authorized by all necessary corporate action and do not and will not, whether with or without the giving of notice or passage of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any properties or assets of the Company pursuant to, the Agreements and Instruments (except for such conflicts, breaches, defaults or Repayment Events or liens, charges or encumbrances as would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect), nor will such action result in any violation of the provisions of the articles of association of the Company or any law, statute, rule, regulation, judgment, order, writ or decree of any Governmental Entity, except for such violations as would not, singly or in the aggregate, result in a Material Adverse Effect. As used herein, a “Repayment Event” means any event or condition which gives the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company.

(xvi) Absence of Labor Dispute. No material labor dispute with the employees of the Company exists or, to the knowledge of the Company, is imminent, and the Company is not aware of any material existing or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers, customers or contractors.

(xvii) Absence of Proceedings. Except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, there is no action, suit, proceeding, inquiry or investigation before or brought by any Governmental Entity now pending or, to the knowledge of the Company, threatened, against or affecting the Company, which would reasonably be expected to result in a Material Adverse Effect, or which would reasonably be expected to materially and adversely affect its respective properties or assets or the consummation of the transactions contemplated in this Agreement or the performance by the Company of its obligations hereunder; and the aggregate of all pending legal or governmental proceedings to which the Company is a party or of which its properties or assets are the subject which are not described in the Registration Statement, the General Disclosure Package and the Prospectus, including ordinary routine litigation incidental to the business, if determined adversely to the Company, would not reasonably be expected to result in a Material Adverse Effect.

(xviii) Accuracy of Exhibits. There are no contracts or documents which are required to be described in the Registration Statement, the General Disclosure Package or the Prospectus or to be filed as exhibits to the Registration Statement which have not been so described and filed as required.

(xix) Absence of Further Requirements. No filing with, or authorization, approval, consent, license, order, registration, qualification or decree of, any Governmental Entity is necessary or required for the performance by the Company of its obligations hereunder, in connection with the Offering, issuance or sale of the Securities hereunder or the consummation of the transactions contemplated by this Agreement, except (A) such as have been already obtained or as may be required under the 1933 Act,

the 1933 Act Regulations, the rules of the NASDAQ Stock Market LLC, U.S. state securities laws or the rules of the Financial Industry Regulatory Authority, Inc. (“FINRA”) and (B) such as have been obtained under the laws and regulations of jurisdictions outside the United States in which the Reserved Securities were offered.

(xx) Possession of Licenses and Permits. The Company possesses such permits, licenses, approvals, consents and other authorizations (collectively, “Governmental Licenses”) issued by the appropriate Governmental Entities necessary to conduct the business now operated by it, including without limitation, all such permits, licenses, approvals, consents and other authorizations required by the United States Food and Drug Administration (the “FDA”), the United States Drug Enforcement Administration or any other federal, state, local or foreign agencies or bodies engaged in the regulation of clinical trials, pharmaceuticals, biologics or biohazardous substances or materials, except where the failure so to possess such Governmental Licenses would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect. The Company is in compliance with the terms and conditions of all Governmental Licenses, except where the failure so to comply would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect. All of the Governmental Licenses are valid and in full force and effect, except where the invalidity of such Governmental Licenses or the failure of such Governmental Licenses to be in full force and effect would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect. The Company has not received any notice of proceedings relating to the revocation or modification of any Governmental Licenses which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Effect. To the extent required by applicable laws and regulations of the FDA, the Company has submitted to the FDA an Investigational New Drug Application or amendment or supplement thereto for each clinical trial it has conducted or sponsored or is conducting or sponsoring; all such submissions, if any, were in material compliance with applicable laws and rules and regulations when submitted and no material deficiencies have been asserted by the FDA with respect to any such submissions.

(xxi) Title to Property. The Company does not own real property. The Company has good and marketable title to all personal and other properties owned by it (excluding for the purpose of this Section (1)(a)(xxi), Intellectual Property (as defined below)), in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind except such as (A) are described in the Registration Statement, the General Disclosure Package and the Prospectus or (B) do not, singly or in the aggregate, materially affect the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Company; and all of the leases and subleases material to the business of the Company and under which the Company holds properties described in the Registration Statement, the General Disclosure Package or the Prospectus, are in full force and effect, and the Company has no notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company under any of the leases or subleases mentioned above, or affecting or questioning the rights of the Company to the continued possession of the leased or subleased premises under any such lease or sublease.

(xxii) Intellectual Property. The Company owns, or has obtained valid, binding and enforceable licenses for the right to use, patents, patent applications, inventions, copyrights, know how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks, trade names or other intellectual property (collectively, “Intellectual Property”) necessary to carry on the business of the Company, in each case as described in the Registration Statement, the General Disclosure Package and the Prospectus (collectively, the “Company Intellectual Property”), except where failure to own, license or have such rights would not individually or in the aggregate, have a Material Adverse Effect; and to the knowledge of the Company, the patents, trademarks, and copyrights, if any, included within the Company Intellectual Property are valid, enforceable, and subsisting. Other than as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, (A) the Company is not obligated to pay a material royalty, grant a license, or provide other material consideration to any third party in connection with the Company Intellectual Property, (B) the Company has not received any notice of any claim of infringement, misappropriation or conflict with any Intellectual Property rights of others with respect to any of the Company’s product candidates or processes or the Company Intellectual Property, (C) to the knowledge of the Company, neither the manufacture nor the sale or use of any of the discoveries, inventions, product candidates or processes of the Company referred to in the Registration Statement, the General Disclosure Package or the Prospectus do or will infringe, misappropriate or violate any existing, non-patent Intellectual Property right or any existing valid, granted patent claim of any third party, and (D) to the knowledge of the Company, no third party has any ownership right in or to any Intellectual Property that is owned by the Company and, to the knowledge of the Company, no third party has any ownership right in or to any Intellectual Property that is exclusively licensed to the Company in any field of use, other than any licensor to the Company of such Intellectual Property.

(xxiii) Patents and Patent Applications. All patents and patent applications owned by or licensed to the Company or under which the Company has rights have, to the knowledge of the Company, been duly and properly filed and maintained; to the knowledge of the Company, each individual associated with the filing and prosecution of such patents and applications has complied with their duty of candor and disclosure to the U.S. Patent and Trademark Office (the “USPTO”) in connection with such patents and applications; and the Company is not aware of any information required to be disclosed to the USPTO that was not disclosed to the USPTO in connection with the prosecution of the aforementioned patents and applications.

(xxiv) Environmental Laws. Except as described in the Registration Statement, the General Disclosure Package and the Prospectus or as would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect, (A) the Company is not in violation of any applicable federal, state, local or foreign statute, law, rule, regulation, ordinance, code, policy or rule of common law or any judicial or administrative interpretation thereof, including any judicial or administrative order, consent, decree or judgment, relating to pollution or protection of human health, the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, laws and

regulations relating to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products, asbestos-containing materials or mold (collectively, “Hazardous Materials”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “Environmental Laws”), (B) the Company has all permits, authorizations and approvals required for its operations under any applicable Environmental Laws and is in compliance with its requirements, (C) there are no pending or, to the knowledge of the Company, threatened, administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings relating to any Environmental Law against the Company and (D) to the knowledge of the Company, there are no events or circumstances that would reasonably be expected to form the basis of an order for clean-up or remediation, or an action, suit or proceeding by any private party or Governmental Entity, against or affecting the Company relating to Hazardous Materials or any Environmental Laws.

(xxv) Accounting Controls. The Company maintains an effective system of “internal control over financial reporting” (as defined under Rule 13-a15(f) and 15d-15(f) under the rules and regulations of the Commission under the 1934 Act (the “1934 Act Regulations”)) that complies with the requirements of the 1934 Act and a system of internal accounting controls sufficient to provide reasonable assurances that (A) transactions are executed in accordance with management’s general or specific authorization; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with IFRS as issued by the IASB and to maintain accountability for assets; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as described in the Registration Statement, the General Disclosure Package and the Prospectus, since the end of the Company’s most recent audited fiscal year, there has been (1) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (2) no change in the Company’s internal control over financial reporting that has materially adversely affected, or is reasonably likely to materially adversely affect, the Company’s internal control over financial reporting.

(xxvi) Disclosure Controls. The Company has established “disclosure controls and procedures” (as defined in Rules 13a-15(e) and 15d-15(e) of the 1934 Act Regulations) that complies with the requirements of the 1934 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 1934 Act is recorded, processed, summarized and reported within the time periods specified in the rules and regulations under the 1934 Act, and that all such information will be 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 1934 Act with respect to such reports.

(xxvii) Preclinical and Clinical Data and Regulatory Compliance. The preclinical tests and clinical trials that are described in, or the results of which are referred to in, the Registration Statement, the General Disclosure Package or the Prospectus (collectively, “Studies”) were and, if still pending, are being conducted in all material respects in accordance with the protocols, procedures and controls designed and approved for such Studies and with standard medical and scientific research procedures; each description of the results of such Studies is accurate and complete in all material respects and fairly presents the data derived from such Studies; and the Company has no knowledge of any other Studies the results of which are inconsistent with, or otherwise call into question, the results described or referred to in the Registration Statement, the General Disclosure Package or the Prospectus. Except as described in the Registration Statement, the General Disclosure Package and the Prospectus, the Company has not received any written notice of, or correspondence from, any Governmental Authority requiring the termination, suspension or material modification of any Studies. The Company has operated and currently is in compliance with the United States Federal Food, Drug, and Cosmetic Act, all applicable rules and regulations of the FDA and other federal, state, local and foreign governmental bodies exercising comparable authority, except where the failure to so operate or be in compliance would not have a Material Adverse Effect.

(xxviii) Payment of Taxes. The Company has filed all necessary Dutch and United States federal, state and foreign income and franchise tax returns that are required to have been filed by them pursuant to applicable federal, state, local, foreign or other law except insofar as the failure to file such returns would not reasonably be expected to result in a Material Adverse Effect, and has paid all taxes due pursuant to such returns or pursuant to any assessment received by the Company, except for such taxes, if any, as are being contested in good faith and as to which adequate reserves have been established by the Company. The charges, accruals and reserves on the books of the Company in respect of any income and corporation tax liability for any years not finally determined are adequate to meet any assessments or re-assessments for additional income tax for any years not finally determined, except to the extent of any inadequacy that would not reasonably be expected to result in a Material Adverse Effect.

To the Company’s knowledge, except for any net income taxes imposed on the Underwriters by the Netherlands or any political subdivision or taxing authority thereof or therein as a result of any present or former connection between the Underwriters and the Netherlands, no transaction, stamp, capital or other issuance, registration, transaction, transfer or withholding tax or duty is payable in The Netherlands by or on behalf of the Underwriters to any taxing authority in connection with (i) the issuance, sale and delivery of the Securities by the Company in the manner contemplated herein; (ii) the purchase from the Company, and the initial sale and delivery by the Underwriters of the Securities to purchasers thereof as contemplated herein; or (iii) the execution and delivery of this Agreement or any other document to be furnished hereunder.

(xxix) Insurance. The Company carries or is entitled to the benefits of insurance, with financially sound and reputable insurers, in such amounts and covering such risks as is customary and adequate for the conduct of its business, and all such insurance is in full force and effect. The Company has not received any notice that it will not be able (A) to

renew its existing insurance coverage as and when such policies expire or (B) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not reasonably be expected to result in a Material Adverse Effect. The Company has not been denied any insurance coverage which it has sought or for which it has applied.

(xxx) Investment Company Act. The Company is not required, and upon the issuance and sale of the Securities as herein contemplated and the application of the net proceeds therefrom as described in the Registration Statement, the General Disclosure Package and the Prospectus will not be required, to register as an “investment company” under the Investment Company Act of 1940, as amended (the “1940 Act”).

(xxxi) Absence of Manipulation. Neither the Company nor, to the Company’s knowledge, any affiliate of the Company has taken, nor will the Company or any affiliate take, directly or indirectly any action which is designed, or would reasonably be expected, to cause or result in, or which constitutes, the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities or to result in a violation of Regulation M under the 1934 Act.

(xxxii) Foreign Corrupt Practices Act. None of the Company or, to the knowledge of the Company, any supervisory or management board member, agent, employee, affiliate or other person acting on behalf of the Company is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of (A) the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “FCPA”), including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA and the Company, or (B) any applicable non-United States anti-bribery statute or regulation, including, without limitation, the OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions (“OECD Convention”), and the UK ▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇ (the “UK Bribery Act”). To the knowledge of the Company, its affiliates have conducted their businesses in compliance with the FCPA, the OECD Convention and the UK Bribery Act and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(xxxiii) Money Laundering Laws. The operations of the Company are and have been conducted at all times in material compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any Governmental Entity (collectively, the “Money Laundering Laws”); and no action, suit or proceeding by or before any Governmental Entity involving the Company with respect to the Money

Laundering Laws is pending or, to the knowledge of the Company, threatened.

(xxxiv) OFAC. None of the Company or, to the knowledge of the Company, any supervisory or management board member, agent, employee, affiliate or representative of the Company is an individual or entity (“Person”) currently the subject or target of any sanctions administered or enforced by the United States Government, including, without limitation, the U.S. Department of the Treasury’s Office of Foreign Assets Control, the United Nations Security Council, the European Union, Her Majesty’s Treasury of the United Kingdom, or other relevant sanctions authority (collectively, “Sanctions”), nor is the Company located, organized or resident in a country or territory that is the subject of Sanctions; and the Company will not directly or indirectly use the proceeds of the sale of the Securities, or lend, contribute or otherwise make available such proceeds to any subsidiaries, joint venture partners or other Person, to fund any activities of or business with any Person, or in any country or territory, that, at the time of such funding, is the subject of Sanctions or in any other manner that will result in a violation by any Person (including any Person participating in the transaction, whether as underwriter, advisor, investor or otherwise) of Sanctions.

(xxxv) Lending Relationships. Except as disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, the Company (i) does not have any material lending or other relationship with any banking or lending affiliate of any Underwriter and (ii) does not intend to use any of the proceeds from the sale of the Securities to repay any outstanding debt owed to any affiliate of any Underwriter.

(xxxvi) Statistical and Market-Related Data. Any statistical and market-related data included in the Registration Statement, the General Disclosure Package or the Prospectus are based on or derived from sources that the Company believes, after reasonable inquiry, to be reliable and accurate and, to the extent required, the Company has obtained the written consent to the use of such data from such sources.

(xxxvii) Listing Approval. The Securities have been approved for listing on the NASDAQ Global Market, subject only to official notice of issuance.

(xxxviii) FINRA Matters. There are no affiliations or associations between any member of FINRA and any of the Company’s officers, directors or 5% or greater shareholders. There are no relationships, direct or indirect, or related-party transactions involving the Company 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.

(xxxix) Sales of Reserved Securities. In connection with any offer and sale of Reserved Securities outside the United States, each preliminary prospectus, the Prospectus and any amendment or supplement thereto, at the time it was distributed, complied in all material respects with any applicable laws or regulations of foreign jurisdictions in which the same is distributed. The Company has not offered, or caused the Representatives to offer, Reserved Securities to any person with the specific intent to unlawfully influence (i) a customer or supplier of the Company or any of its affiliates to alter the customer’s or

supplier’s level or type of business with any such entity or (ii) a trade journalist or publication to write or publish favorable information about the Company or any of its affiliates, or their respective businesses or products.

(b) Certificates. Any certificate signed by any management board member of the Company delivered to the Representatives or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

SECTION 2. Sale and Delivery to Underwriters; Closing.

(a) Initial Securities. On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company agrees to sell to each Underwriter, severally and not jointly, and each Underwriter, severally and not jointly, agrees to purchase from the Company, at the price per share set forth in Schedule A, that number of Initial Securities set forth in Schedule A opposite the name of such Underwriter, plus any additional number of Initial Securities which such Underwriter may become obligated to purchase pursuant to the provisions of Section 10 hereof, subject, in each case, to such adjustments among the Underwriters as the Representatives in their sole discretion shall make to eliminate any sales or purchases of fractional shares.

(b) Option Securities. 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 Underwriters, severally and not jointly, to purchase up to an additional [—] Ordinary Shares, at the price per share set forth in Schedule A, less an amount per share equal to any dividends or distributions declared by the Company and payable on the Initial Securities (on a per-share basis) but not payable on the Option Securities. The option hereby granted may be exercised for 30 days after the date hereof and may be exercised in whole or in part at any time from time to time upon notice by the Representatives to the Company setting forth the number of Option Securities as to which the several Underwriters are then exercising the option and the time and date of payment and delivery for such Option Securities. Any such time and date of delivery (a “Date of Delivery”) shall be determined by the Representatives, but any Date of Delivery occurring after the Closing Time shall not be later than seven full business days (i.e. a day on which banks are generally open for ordinary business in Amsterdam, the Netherlands, and New York, United States of America, a “Business Day”) nor earlier than two full Business Days after the exercise of said option, nor in any event prior to the Closing Time. If the option is exercised as to all or any portion of the Option Securities, each of the Underwriters, acting severally and not jointly, will purchase that proportion of the total number of Option Securities then being purchased which the number of Initial Securities set forth in Schedule A opposite the name of such Underwriter bears to the total number of Initial Securities, subject, in each case, to such adjustments as the Representatives in their sole discretion shall make to eliminate any sales or purchases of fractional shares.

(c) Payment. Payment of the purchase price for the Initial Securities shall be made at the offices of ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, ▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇ or at such other place as shall be agreed upon by the Representatives and the Company, at 9:00 A.M. (New York City time) on the third (fourth, if the pricing in connection

with the Offering occurs after 4:30 P.M. (New York City time) on any given day) Business Day after the date hereof (unless postponed in accordance with the provisions of Section 10), or such other time not later than ten Business Days after such date as shall be agreed upon by the Representatives and the Company (such time and date of payment and delivery being herein called “Closing Time”). Delivery of the Initial Securities at the Closing Time shall be made through the facilities of The Depository Trust Company unless the Representatives shall otherwise instruct.

In addition, in the event that any or all of the Option Securities are purchased by the Underwriters, payment of the purchase price for such Option Securities shall be made at the above-mentioned offices, or at such other place as shall be agreed upon by the Representatives and the Company, on each Date of Delivery as specified in the notice from the Representatives to the Company. Delivery of the Option Securities on each such Date of Delivery shall be made through the facilities of The Depository Trust Company unless the Representatives shall otherwise instruct.

Payment shall be made to the Company by wire transfer of immediately available funds to a bank account designated by the Company against delivery to the Representatives for the respective accounts of the Underwriters of the Securities to be purchased by them. It is understood that each Underwriter has authorized the Representatives, for its account, to accept delivery of, receipt for, and make payment of the purchase price for, the Initial Securities and the Option Securities, if any, which it has agreed to purchase. The Representatives, collectively and not as representatives of the Underwriters, may (but shall not be obligated to) make payment of the purchase price for the Initial Securities or the Option Securities, if any, to be purchased by any Underwriter whose funds have not been received by the Closing Time or the relevant Date of Delivery, as the case may be, but such payment shall not relieve such Underwriter from its obligations hereunder.

For purposes hereof, the difference between the initial public offering price per share for the Securities and the purchase price per share for the Securities to be paid by the several Underwriters, each set forth on Schedule A, is the fee paid by the Company to the several Underwriters in consideration of the services rendered by the Underwriters to the Company hereunder.

SECTION 3. Covenants of the Company. The Company covenants with each Underwriter as follows:

(a) Compliance with Securities Regulations and Commission Requests. The Company, subject to Section 3(b), will comply with the requirements of Rule 430A, and will notify the Representatives promptly and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement shall become effective or any amendment or supplement to the Prospectus shall have been filed, (ii) of the receipt of any comments from the Commission, (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for additional information, (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment or of any order preventing or suspending the use of any preliminary prospectus or the Prospectus, or of the suspension of the

qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes or of any examination pursuant to Section 8(d) or 8(e) of the 1933 Act concerning the Registration Statement and (v) if the Company becomes the subject of a proceeding under Section 8A of the 1933 Act in connection with the Offering of the Securities. The Company will effect all filings required under Rule 424(b), in the manner and within the time period required by Rule 424(b) (without reliance on Rule 424(b)(8)), and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort to prevent the issuance of any stop order, prevention or suspension and, if any such order is issued, to obtain the lifting thereof at the earliest possible moment.

(b) Continued Compliance with Securities Laws. The Company will comply with the 1933 Act and the 1933 Act Regulations so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Registration Statement, the General Disclosure Package and the Prospectus. If at any time when a prospectus relating to the Securities is (or, but for the exception afforded by Rule 172 of the 1933 Act Regulations (“Rule 172”), would be) required by the 1933 Act to be delivered in connection with sales of the Securities, any event shall occur or condition shall exist as a result of which it is necessary, in the reasonable opinion of counsel for the Underwriters or for the Company, to (i) amend the Registration Statement in order that the Registration Statement will not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) amend or supplement the General Disclosure Package or the Prospectus in order that the General Disclosure Package or the Prospectus, as the case may be, will not include any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in the light of the circumstances existing at the time it is delivered to a purchaser or (iii) amend the Registration Statement or amend or supplement the General Disclosure Package or the Prospectus, as the case may be, in order to comply with the requirements of the 1933 Act or the 1933 Act Regulations, the Company will promptly (A) give the Representatives notice of such event, (B) prepare any amendment or supplement as may be necessary to correct such statement or omission or to make the Registration Statement, the General Disclosure Package or the Prospectus comply with such requirements and, a reasonable amount of time prior to any proposed filing or use, furnish the Representatives with copies of any such amendment or supplement and (C) file with the Commission any such amendment or supplement; provided that the Company shall not file or use any such amendment or supplement to which the Representatives or counsel for the Underwriters shall reasonably object. The Company will furnish to the Underwriters such number of copies of such amendment or supplement as the Underwriters may reasonably request. The Company has given the Representatives notice of any filings made pursuant to the 1934 Act or the 1934 Act Regulations within 48 hours prior to the Applicable Time; the Company will give the Representatives notice of its intention to make any such filing from the Applicable Time to the Closing Time and will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing, as the case may be, and will not file or use any such document to which the Representatives or counsel for the Underwriters shall reasonably object.

(c) Delivery of Registration Statements. The Company has furnished or will deliver to the Representatives and counsel for the Underwriters, without charge, signed copies of the Registration Statement as originally filed and each amendment thereto (including exhibits filed therewith) and signed copies of all consents and certificates of experts, and will also deliver to the Representatives, without charge, a conformed copy of the Registration Statement as originally filed and each amendment thereto (without exhibits) for each of the Underwriters. The copies of the Registration Statement and each amendment thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(d) Delivery of Prospectuses. The Company has delivered to each Underwriter, without charge, as many copies of each preliminary prospectus as such Underwriter reasonably requested, and the Company hereby consents to the use of such copies for purposes permitted by the 1933 Act. The Company will furnish to each Underwriter, without charge, during the period when a prospectus relating to the Securities is (or, but for the exception afforded by Rule 172, would be) required to be delivered under the 1933 Act, such number of copies of the Prospectus (as amended or supplemented) as such Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(e) Blue Sky Qualifications. The Company will cooperate with the Underwriters and counsel for the Underwriters to qualify the Securities for offering and sale under the applicable securities laws of such states and other jurisdictions (domestic or foreign) as the Representatives may designate and to maintain such qualifications in effect so long as required to complete the distribution of the Securities; provided, however, that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject.

(f) Rule 158. The Company will timely file such reports pursuant to the 1934 Act as are necessary in order to make generally available to its securityholders as soon as practicable an earnings statement for the purposes of, and to provide to the Underwriters the benefits contemplated by, the last paragraph of Section 11(a) of the 1933 Act.

(g) Use of Proceeds. The Company will use the net proceeds received by it from the sale of the Securities in the manner specified in the Registration Statement, the General Disclosure Package and the Prospectus under “Use of Proceeds.”

(h) Listing. The Company will use its best efforts to effect the listing of the Ordinary Shares (including the Securities) on the NASDAQ Global Market, subject to notice of issuance.

(i) Restriction on Sale of Securities. During a period of 180 days from the date of the Prospectus, the Company will not, without the prior written consent of the Representatives, (i) directly or indirectly, offer, pledge, sell, contract to sell (including any short sale), sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of any Ordinary Shares or any securities

convertible into or exercisable or exchangeable for Ordinary Shares (“Lock-Up Securities”) or file any registration statement under the 1933 Act with respect to any of the foregoing or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Ordinary Shares, whether any such swap or transaction described in clause (i) or (ii) above is to be settled by delivery of Ordinary Shares or such other securities, in cash or otherwise, other than (a) the Securities to be sold hereunder, (b) the grant of options or other equity-based awards pursuant to the terms of a plan disclosed in the Registration Statement, or the issuance of any Ordinary Shares upon the exercise of such options or other equity-based awards, provided that the recipient of such options or other equity-based awards (to the extent that such options or other equity-based awards shall vest within the period ending 180 days after the date of the Prospectus) or such Ordinary Shares shall execute and deliver a lock up agreement substantially in the form of Exhibit A hereto prior to receiving such options, equity-based awards or Ordinary Shares unless such recipient has previously executed such agreement, (c) the filing by the Company of a registration statement on Form S-8 or a successor form thereto solely with respect to the Company’s benefit plans disclosed in the Registration Statement, the General Disclosure Package and the Prospectus, (d) the establishment of a trading plan pursuant to Rule 10b5-1 under the 1934 Act, for the repurchase of Ordinary Shares, provided that such plan does not provide for the repurchase of Ordinary Shares during the 180-day restricted period and no public announcement or filing under the 1934 Act regarding the establishment of such plan shall be required of or voluntarily made by or on behalf of the Company or any other person, (e) the issuance of Ordinary Shares or securities exercisable for, convertible into or exchangeable for Ordinary Shares in connection with any acquisition, collaboration, licensing or other joint venture or strategic transaction or any debt financing transaction involving the Company; provided that in the case of clause (e), that such issuances shall not be greater than 10% of the Securities to be sold hereunder and the recipients of such Securities agree to be bound by a lock up agreement substantially in the form of Exhibit A hereto, (f) the transfer of Ordinary Shares to the Company by Stichting ProQR Therapeutics Participation (“ESOP Foundation”), which is the foundation holding Ordinary Shares in the capital of the Company for the purpose of the Company’s existing employee stock option plan (the “Existing ESOP”), in connection with the termination of the ESOP Foundation’s role in connection with the Existing ESOP prior to completion of the Offering, (g) an issue, repurchase, transfer or cancellation of Ordinary Shares or depositary receipts in connection with any transfer in connection with the restructuring of the issued share capital of the Company related to the rebalancing between holders of Ordinary Shares or between holders of Ordinary Shares and the Company, in connection with a reverse stock split prior to the completion of the Offering and only to realize the appropriate share capital and par value of the Ordinary Shares at the time of completion of the Offering, that has been approved by the Underwriters, which approval shall not be unreasonably withheld, (h) the granting of a call option to a protective foundation to be set up to protect the Company from possible threats to the strategy, continuity, independence and/or identity of the Company or the business connected with it (the “Protective Call Option”), or (i) the issuance of preferred shares pursuant to the exercise of the Protective Call Option in accordance with its terms.

(j) Certain Releases or Waivers. If the Representatives, in their sole discretion, agree to release or waive the restrictions set forth in a lock-up agreement described in Section 5(l) hereof for a supervisory or management board member or senior manager of the Company and provides the Company with notice of the impending release or waiver at least two

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 B hereto through a major news service or as otherwise permitted under FINRA Rule 5131 at least two Business Days before the effective date of the release or waiver. The provisions of this paragraph will not apply if (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

(k) Reporting Requirements. The Company, during the period when a Prospectus relating to the Securities is (or, but for the exception afforded by Rule 172, would be) required to be delivered under the 1933 Act, will file all documents required to be filed with the Commission pursuant to the 1934 Act within the time periods required by the 1934 Act and 1934 Act Regulations. Additionally, the Company shall report the use of proceeds from the issuance of the Securities as may be required under Rule 463 of the 1933 Act Regulations.

(l) Issuer Free Writing Prospectuses. The Company agrees that, unless it obtains the prior written consent of the Representatives, it will not make any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus,” or a portion thereof, required to be filed by the Company with the Commission or retained by the Company under Rule 433; provided that the Representatives will be deemed to have consented to the Issuer Free Writing Prospectuses listed on Schedule B-2 hereto and any “road show that is a written communication” within the meaning of Rule 433(d)(8)(i) that has been reviewed by the Representatives. The Company represents that it has treated or agrees that it will treat each such free writing prospectus consented to, or deemed consented to, by the Representatives as an “issuer free writing prospectus,” as defined in Rule 433, and that it has complied and will comply with the applicable requirements of Rule 433 with respect thereto, including timely filing with the Commission where required, legending and record keeping. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement, any preliminary prospectus or the Prospectus or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify the Representatives and will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission.

(m) Testing-the-Waters Materials. If at any time following the distribution of any Written Testing-the-Waters Communication there occurred or occurs an event or development as a result of which such Written Testing-the-Waters Communication included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify the Representatives and will promptly amend or supplement, at its own expense, such Written Testing-the-Waters Communication to eliminate or correct such untrue statement or omission.

(n) Emerging Growth Company Status. 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 (i) completion of the distribution of the Securities within the meaning of the 1933 Act and (ii) completion of the 180-day restricted period referred to in Section 3(i).

(o) Compliance with FINRA Rules. The Company hereby agrees that it will ensure that the Reserved Securities will be restricted as required by FINRA or the FINRA rules from sale, transfer, assignment, pledge or hypothecation for a period of three months following the date of this Agreement. The Underwriters will notify the Company as to which persons will need to be so restricted. At the request of the Underwriters, the Company will direct the transfer agent to place a stop transfer restriction upon such securities for such period of time. Should the Company release, or seek to release, from such restrictions any of the Reserved Securities, the Company agrees to reimburse the Underwriters for any reasonable expenses (including, without limitation, legal expenses) they incur in connection with such release.

SECTION 4. Payment of Expenses.

(a) Expenses. The Company will pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and each amendment thereto, (ii) the preparation, printing and delivery to the Underwriters of copies of each preliminary prospectus, each Issuer Free Writing Prospectus and the Prospectus and any amendments or supplements thereto and any costs associated with electronic delivery of any of the foregoing by the Underwriters to investors, (iii) the preparation, issuance and delivery of the Securities to the Underwriters, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Securities to the Underwriters, (iv) the fees and disbursements of the Company’s counsel, accountants and other advisors, (v) the qualification of the Securities under securities laws in accordance with the provisions of Section 3(e) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection therewith and in connection with the preparation of a “Blue Sky Survey” and any supplement thereto, in an amount not to exceed $5,000, (vi) the fees and expenses of any transfer agent or registrar for the Securities, (vii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the Securities, including without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged by the Company in connection with the road show presentations, travel and lodging expenses of the Company’s officers and employees and any such consultants (provided that the travel, lodging and any car travel expenses of the representatives of the Underwriters shall be paid by the Underwriters), and 50% of the cost of any aircraft and other transportation chartered in connection with the road show, (viii) the filing fees incident to, and the reasonable fees and disbursements of counsel to the Underwriters in connection with, the review by FINRA of the terms of the sale of the Securities, in an amount not to exceed $35,000, (ix) the fees and expenses incurred in connection with the listing of the Securities on the NASDAQ Global Market, (x) 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 Securities made by the Underwriters caused by a breach of the representation contained in the third sentence of Section 1(a)(ii) and (xi) the costs and expenses

of the Underwriters, including the reasonable fees and disbursements of counsel for the Underwriters, in connection with matters related to the Reserved Securities which are designated by the Company for sale to Invitees. Notwithstanding the above, except as provided in this Section 4(a), Section 4(b) below, Section 6 (Indemnification) and Section 7 (Contribution), the Underwriters will pay all of their costs and expenses, including fees and expenses of their counsel.

(b) Termination of Agreement. If this Agreement is terminated by the Representatives in accordance with the provisions of Section 5, Section 9(a)(i) or Section 9(a)(iii) hereof, the Company shall reimburse the Underwriters for all of their reasonably documented out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters.

SECTION 5. Conditions of Underwriters’ Obligations. The obligations of the several Underwriters hereunder are subject to the accuracy of the representations and warranties of the Company contained herein or in certificates of any member of the management board of the Company delivered pursuant to the provisions hereof, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions:

(a) Effectiveness of Registration Statement; Rule 430A Information. The Registration Statement, including any Rule 462(b) Registration Statement, has become effective and, at the Closing Time, no stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto has been issued under the 1933 Act or 1934 Act, no order preventing or suspending the use of any preliminary prospectus or the Prospectus has been issued and no proceedings for any of those purposes have been instituted or are pending or, to the Company’s knowledge, contemplated; and the Company has complied in all material respects with each request (if any) from the Commission for additional information. A prospectus containing the Rule 430A Information shall have been filed with the Commission in the manner and within the time frame required by Rule 424(b) without reliance on Rule 424(b)(8) or a post-effective amendment providing such information shall have been filed with, and declared effective by, the Commission in accordance with the requirements of Rule 430A.

(b) Opinions of United States Counsel for Company. At the Closing Time, the Representatives shall have received the opinions of ▇▇▇▇▇▇▇ Procter LLP, United States counsel for the Company, dated the Closing Time, including with respect to intellectual property and regulatory matters, in form and substance satisfactory to counsel for the Underwriters and agreed upon between the parties, together with signed or reproduced copies of such letter for each of the other Underwriters.

(c) Negative Assurance Letter of United States Counsel for the Company. At the Closing Time, the Representatives shall have received the negative assurance letter of ▇▇▇▇▇▇▇ Procter LLP, United Stated counsel for the Company, dated the Closing Time, in form and substance satisfactory to counsel for the Underwriters and agreed upon between the parties, together with signed or reproduced copies of such letter for each of the other Underwriters.

(d) Opinion of Dutch Counsel for the Company. At the Closing Time, the Representatives shall have received the opinion of NautaDutilh N.V., Dutch counsel for the

Company, dated the Closing Time, including with respect to certain regulatory and Dutch tax matters, in the form and substance satisfactory to counsel of the Underwriters and agreed upon between the parties, together with signed or reproduced copies of such letter for each of the other Underwriters.

(e) Opinion of United States Counsel for Underwriters. At the Closing Time, the Representatives shall have received the opinion of ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, counsel for the Underwriters, dated the Closing Time, together with signed or reproduced copies of such letter for each of the other Underwriters with respect to such matters as the Representatives may reasonably request. In giving such opinion such counsel may rely, as to all matters governed by the laws of jurisdictions other than the law of the State of New York, the General Corporation Law of the State of Delaware and the federal securities laws of the United States, upon the opinions of counsel satisfactory to the Representatives. Such counsel may also state that, insofar as such opinion involves factual matters, they have relied, to the extent they deem proper, upon certificates of officers and other representatives of the Company and certificates of public officials.

(f) Opinion of Dutch Counsel for the Underwriters. At the Closing Time, the Representatives shall have received the opinion of ▇▇▇▇▇▇ N.V., Dutch counsel for the Underwriters in connection with the offer and sale of the Securities, dated the Closing Time, in form and substance satisfactory to the Underwriters.

(g) Certificate. At the Closing Time, there shall not have been, since the date hereof or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or prospects of the Company, whether or not arising in the ordinary course of business, and the Representatives shall have received a certificate of a management board member, dated the Closing Time, to the effect that (i) from the date of this Agreement through the Closing Time, there has been no Material Adverse Effect, (ii) the representations and warranties of the Company in this Agreement are true and correct with the same force and effect as though expressly made at and as of the Closing Time, (iii) the Company has complied in all material respects with all agreements and satisfied all conditions on its part to be performed or satisfied at or prior to the Closing Time, and (iv) no stop order suspending the effectiveness of the Registration Statement under the 1933 Act has been issued and remains outstanding, no order preventing or suspending the use of any preliminary prospectus or the Prospectus has been issued and remains outstanding and no proceedings for any of those purposes have been instituted or are pending or, to their knowledge, contemplated.

(h) Accountant’s Comfort Letter. At the time of the execution of this Agreement, the Representatives shall have received from Deloitte & Touche LLP a letter, dated such date, in form and substance satisfactory to the Representatives, together with signed or reproduced copies of such letter for each of the other Underwriters containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the General Disclosure Package and the Prospectus.

(i) Bring-down Comfort Letter. At the Closing Time, the Representatives shall have

received from Deloitte & Touche LLP a letter, dated as of the Closing Time, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (h) of this Section, except that the specified date referred to shall be a date not more than three Business Days prior to the Closing Time.

(j) Approval of Listing. At the Closing Time, the Securities shall have been approved for listing on the NASDAQ Global Market, subject only to official notice of issuance.

(k) No Objection. FINRA shall have confirmed that it has not raised any objection with respect to the fairness and reasonableness of the underwriting terms and arrangements relating to the Offering of the Securities.

(l) Lock-up Agreements. At the date of this Agreement, the Representatives shall have received an agreement substantially in the form of Exhibit A hereto signed by the persons and entities listed on Schedule C hereto.

(m) Conditions to Purchase of Option Securities. In the event that the Underwriters exercise their option provided in Section 2(b) hereof to purchase all or any portion of the Option Securities, the representations and warranties of the Company contained herein and the statements in any certificates furnished by the Company hereunder shall be true and correct as of each Date of Delivery and, at the relevant Date of Delivery, the Representatives shall have received:

(i) Certificate. A certificate, dated such Date of Delivery, of a management board member of the Company confirming that the certificate delivered at the Closing Time pursuant to Section 5(g) hereof remains true and correct as of such Date of Delivery.

(ii) Opinions of United States Counsel for Company. If requested by the Representatives, the opinions of ▇▇▇▇▇▇▇ Procter LLP, U.S. counsel for the Company, including with respect to intellectual property and regulatory matters, in form and substance satisfactory to counsel for the Underwriters and agreed upon between the parties, dated such Date of Delivery, relating to the Option Securities to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(b) hereof.

(iii) Negative Assurance Letter of United States Counsel for the Company. If requested by the Representatives, the negative assurance letter of ▇▇▇▇▇▇▇ Procter LLP, U.S. counsel for the Company, in form and substance satisfactory to counsel for the Underwriters and agreed upon between the parties, dated such Date of Delivery, relating to the Option Securities to be purchased on such Date of Delivery and otherwise to the same effect as the negative assurance letter required by Section 5(c) hereof.

(iv) Opinion of Dutch Counsel for the Company. If requested by the Representatives, the opinion of NautaDutilh N.V., Dutch counsel for the Company, including with respect to certain regulatory and Dutch tax matters, in the form and substance satisfactory to counsel of the Underwriters and agreed upon between the parties, dated such Date of Delivery, relating to the Option Securities to be purchased on

such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(d) hereof.

(v) Opinion of United States Counsel for Underwriters. If requested by the Representatives, the opinion of ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, counsel for the Underwriters, dated such Date of Delivery, relating to the Option Securities to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(e) hereof.

(vi) Opinion of Dutch Counsel for the Underwriters. If requested by the Representatives, the opinion of ▇▇▇▇▇▇ N.V., Dutch counsel for the Underwriters in connection with the offer and sale of the Securities, dated such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(f) hereof.

(vii) Bring-down Comfort Letter. If requested by the Representatives, a letter from Deloitte & Touche LLP, in form and substance satisfactory to the Representatives and dated such Date of Delivery, substantially in the same form and substance as the letter furnished to the Representatives pursuant to Section 5(h) hereof, except that the “specified date” in the letter furnished pursuant to this paragraph shall be a date not more than three Business Days prior to such Date of Delivery.

(n) Notarial Deeds. The conversion of ProQR Therapeutics B.V. into a Dutch public company with limited liability, whereby the Company will be renamed ProQR Therapeutics N.V., shall have been effected by one or more notarial deeds.

(o) Additional Documents. At the Closing Time and at each Date of Delivery (if any) counsel for the Underwriters shall have been furnished with such documents and opinions as they may reasonably require for the purpose of enabling them to pass upon the issuance and sale of the Securities as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Securities as herein contemplated shall be reasonably satisfactory in form and substance to the Representatives and counsel for the Underwriters.

(p) Termination of Agreement. If any condition specified in this Section shall not have been fulfilled when and as required to be fulfilled, this Agreement, or, in the case of any condition to the purchase of Option Securities on a Date of Delivery which is after the Closing Time, the obligations of the several Underwriters to purchase the relevant Option Securities, may be terminated by the Representatives by notice to the Company at any time at or prior to Closing Time or such Date of Delivery, as the case may be, and such termination shall be without liability of any party to any other party except as provided in Section 4 and except that Sections 1, 6, 7, 8, 14, 15 and 16 shall survive any such termination and remain in full force and effect.

SECTION 6. Indemnification.

(a) Indemnification of Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its directors and officers, its affiliates (as such term is defined in Rule 501(b) of the 1933 Act Regulations (each, an “Affiliate”)), its selling agents and each

person, if any, who controls any Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows:

(i) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including the Rule 430A Information, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact included (A) in any preliminary prospectus, any Issuer Free Writing Prospectus, any Written Testing-the-Waters Communication, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto), or (B) in any materials or information provided to investors by, or with the approval of, the Company in connection with the marketing of the Offering of the Securities (“Marketing Materials”), including any roadshow or investor presentations made to investors by the Company (whether in person or electronically), or the omission or alleged omission in any preliminary prospectus, Issuer Free Writing Prospectus, any Written Testing-the-Waters Communication, Prospectus or in any Marketing Materials of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(ii) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company;

(iii) against any and all expense whatsoever, as incurred (including the reasonable fees and disbursements of counsel chosen by the Representatives), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under (i) or (ii) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in the Registration Statement (or any amendment thereto), including the Rule 430A Information, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with the Underwriter Information.

(b) Indemnification of Company, Directors and Senior Management. Each Underwriter severally and not jointly agrees to indemnify and hold harmless the Company, its directors, and each of its senior managers who signed the Registration Statement, and each

person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act, against any and all loss, liability, claim, damage and expense described in the indemnity contained in subsection (a) of this Section, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), including the Rule 430A Information, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with the Underwriter Information.

(c) Actions against Parties; Notification. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) above, counsel to the indemnified parties shall be selected by the Representatives, and, in the case of parties indemnified pursuant to Section 6 (b) above, counsel to the indemnified parties shall be selected by the Company. An indemnifying party may participate at its own expense in the defense of any such action; provided, however, that counsel to the indemnifying party shall not (except with the consent of the indemnified party) also be counsel to the indemnified party. In no event shall the indemnifying parties be liable for the reasonable fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d) Settlement without Consent if Failure to Reimburse. If at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for reasonable fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) or settlement of any claim in connection with any violation referred to in Section 6(e) effected without its written consent if (i) such settlement is entered into more than 60 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

(e) Indemnification for Reserved Securities. In connection with the offer and sale of the Reserved Securities, the Company agrees to indemnify and hold harmless the Underwriters,

their Affiliates and selling agents and each person, if any, who controls any Underwriter within the meaning of either Section 15 of the 1933 Act or Section 20 of the 1934 Act, from and against any and all loss, liability, claim, damage and expense (including, without limitation, any legal or other expenses reasonably incurred in connection with defending, investigating or settling any such action or claim), as incurred, (i) arising out of the violation of any applicable laws or regulations of foreign jurisdictions where Reserved Securities have been offered, (ii) arising out of any untrue statement or alleged untrue statement of a material fact contained in material prepared by or with the consent of the Company for distribution to Invitees in connection with the offering of the Reserved Securities or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, (iii) caused by the failure of any Invitee to pay for and accept delivery of Reserved Securities which have been orally confirmed for purchase by such Invitee by the Closing Time or (iv) related to, or arising out of or in connection with, the offering of the Reserved Securities.

(f) The indemnity and contribution agreements contained in Section 6 and 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 Securities 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 Section 6 and Section 7.

SECTION 7. Contribution. If the indemnification provided for in Section 6 hereof is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriters, on the other hand, from the Offering of the Securities pursuant to this Agreement or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and of the Underwriters, on the other hand, in connection with the statements or omissions, or in connection with any violation of the nature referred to in Section 6(e) hereof, which resulted in such losses, liabilities, claims, damages or expenses, 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 hand, in connection with the Offering of the Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the Offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company, on the one hand, and the total underwriting discount received by the Underwriters, on the other hand, in each case as set forth on the cover of the Prospectus, bear to the aggregate initial public offering price of the Securities as set forth on the cover of the Prospectus.

The relative fault of the Company, on the one hand, and the Underwriters, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission or any violation of the nature referred to in Section 6(e) hereof.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 7 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 in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

Notwithstanding the provisions of this Section 7, no Underwriter shall be required to contribute any amount in excess of the underwriting commissions received by such Underwriter in connection with the Securities underwritten by it and distributed to the public.

No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the ▇▇▇▇ ▇▇▇) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

For purposes of this Section 7, each person, if any, who controls an Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act and each Underwriter’s Affiliates and selling agents shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company. The Underwriters’ respective obligations to contribute pursuant to this Section 7 are several in proportion to the number of Initial Securities set forth opposite their respective names in Schedule A hereto and not joint.

SECTION 8. Representations, Warranties and Agreements to Survive. All representations, warranties and agreements contained in this Agreement or in certificates of the Company submitted pursuant hereto, shall remain operative and in full force and effect regardless of (i) any investigation made by or on behalf of any Underwriter or its Affiliates or selling agents, any person controlling any Underwriter, its officers or directors or any person controlling the Company and (ii) delivery of and payment for the Securities.

SECTION 9. Termination of Agreement.

(a) Termination. The Representatives may terminate this Agreement, by notice to the Company, at any time at or prior to the Closing Time (i) if there has been, in the reasonable

judgment of the Representatives, since the time of execution of this Agreement or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or prospects of the Company, whether or not arising in the ordinary course of business, or (ii) if there has occurred any material adverse change in the financial markets in the United States or the international financial markets, any outbreak of hostilities or escalation thereof or other calamity or crisis or any change or development involving a prospective change in national or international political, financial or economic conditions, in each case the effect of which is such as to make it, in the reasonable judgment of the Representatives, impracticable or inadvisable to proceed with the completion of the Offering or to enforce contracts for the sale of the Securities, or (iii) if trading in any securities of the Company has been suspended or materially limited by the Commission or the NASDAQ Global Market, or (iv) if trading generally on the NYSE MKT or the New York Stock Exchange or in the NASDAQ Global Market has been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required by, any of said exchanges or by order of the Commission, FINRA or any other governmental authority, or (v) a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States or with respect to Clearstream or Euroclear systems in Europe, or (vi) if a banking moratorium has been declared by either Federal or New York authorities.

(b) Liabilities. If this Agreement is terminated pursuant to this Section, such termination shall be without liability of any party to any other party except as provided in Section 4 hereof, and provided further that Sections 1, 6, 7, 8, 14, 15 and 16 shall survive such termination and remain in full force and effect.

SECTION 10. Default by One or More of the Underwriters. If one or more of the Underwriters shall fail at the Closing Time or a Date of Delivery to purchase the Securities which it or they are obligated to purchase under this Agreement (the “Defaulted Securities”), the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Securities in such amounts as may be agreed upon and upon the terms herein set forth; if, however, the Representatives shall not have completed such arrangements within such 24-hour period, then:

(i) if the number of Defaulted Securities does not exceed 10% of the number of Securities to be purchased on such date, each of the non-defaulting Underwriters shall be obligated, severally and not jointly, to purchase the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of all non-defaulting Underwriters, or

(ii) if the number of Defaulted Securities exceeds 10% of the number of Securities to be purchased on such date, this Agreement or, with respect to any Date of Delivery which occurs after the Closing Time, the obligation of the Underwriters to purchase, and the Company to sell, the Option Securities to be purchased and sold on such Date of Delivery shall terminate without liability on the part of any non-defaulting Underwriter.

No action taken pursuant to this Section 10 shall relieve any defaulting Underwriter from liability in respect of its default.

In the event of any such default which does not result in a termination of this Agreement or, in the case of a Date of Delivery which is after the Closing Time, which does not result in a termination of the obligation of the Underwriters to purchase and the Company to sell the relevant Option Securities, as the case may be, either the (i) Representatives or (ii) the Company shall have the right to postpone Closing Time or the relevant Date of Delivery, as the case may be, for a period not exceeding seven days in order to effect any required changes in the Registration Statement, the General Disclosure Package or the Prospectus or in any other documents or arrangements. As used herein, the term “Underwriter” includes any person substituted for an Underwriter under this Section 10.

SECTION 11. Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriters shall be directed to (i) Leerink Partners LLC, Attention: Syndicate Department, ▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇, or by email at ▇▇▇▇▇▇▇▇▇@▇▇▇▇▇▇▇.▇▇▇, or by phone at ▇▇▇-▇▇▇-▇▇▇▇ and (ii) to Deutsche Bank Securities Inc., ▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: Equity Capital Markets – Syndicate Desk, fax: (▇▇▇) ▇▇▇-▇▇▇▇ , with a copy to Deutsche Bank Securities Inc., ▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇^▇▇ ▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: General Counsel, fax: (▇▇▇) ▇▇▇-▇▇▇▇; notices to the Company shall be directed to it at ProQR Therapeutics B.V., ▇▇▇▇▇▇▇▇▇ ▇▇, ▇▇▇▇ ▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇▇▇▇▇▇▇▇, attention of the Chief Executive Officer (telephone: + ▇▇ (▇) ▇▇ ▇ ▇▇ ▇▇ 32).

SECTION 12. No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) the purchase and sale of the Securities pursuant to this Agreement, including the determination of the initial public offering price of the Securities and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the several Underwriters, on the other hand, (b) in connection with the Offering of the Securities and the process leading thereto, each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company or its shareholders, creditors, employees or any other party, (c) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favor of the Company with respect to the Offering of the Securities or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the Offering of the Securities except the obligations expressly set forth in this Agreement, (d) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company and (e) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the Offering of the Securities and the Company has consulted its own respective legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

SECTION 13. Parties. This Agreement shall each inure to the benefit of and be binding upon the Underwriters and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Underwriters and the Company and their respective successors and

the controlling persons and officers and directors referred to in Sections 6 and 7 and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Underwriters and the Company and their respective successors, and said controlling persons and officers and directors and their heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Securities from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

SECTION 14. Trial by Jury. The Company (on its behalf and, to the extent permitted by applicable law, on behalf of its shareholders and affiliates) and each of the Underwriters hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

SECTION 15. GOVERNING LAW. THIS AGREEMENT AND ANY CLAIM, CONTROVERSY OR DISPUTE ARISING UNDER OR RELATED TO THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF, THE STATE OF NEW YORK WITHOUT REGARD TO ITS CHOICE OF LAW PROVISIONS.

SECTION 16. Consent to Jurisdiction; Waiver of Immunity. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby shall be instituted in (i) the federal courts of the United States of America located in the City and County of New York, Borough of Manhattan or (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”), 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, 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.

SECTION 17. TIME. TIME SHALL BE OF THE ESSENCE OF THIS AGREEMENT. EXCEPT AS OTHERWISE SET FORTH HEREIN, SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME.

SECTION 18. Counterparts. This Agreement may be executed in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same agreement.

SECTION 19. Effect of Headings. The Section headings herein are for convenience only and shall not affect the construction hereof.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument, along with all counterparts, will become a binding agreement among the Underwriters and the Company in accordance with its terms.


Very truly yours,

PROQR THERAPEUTICS B.V.

By
		Name:
		Title:


CONFIRMED AND ACCEPTED, as of the date first above written:

LEERINK PARTNERS LLC

By
		Name:
		Title:

CONFIRMED AND ACCEPTED, as of the date first above written:

DEUTSCHE BANK SECURITIES INC.

By
		Name:
		Title:

By
		Name:
		Title:

For themselves and as Representatives of the other Underwriters named in Schedule A hereto.

Signature Page to Underwriting Agreement

SCHEDULE A

The initial public offering price per share for the Securities shall be $[—].

The purchase price per share for the Securities to be paid by the several Underwriters shall be $[—], being an amount equal to the initial public offering price set forth above less $[—] per share, subject to adjustment in accordance with Section 2(b) for dividends or distributions declared by the Company and payable on the Initial Securities but not payable on the Option Securities.


Name of Underwriter		Number of Initial Securities
Leerink Partners LLC
Deutsche Bank Securities Inc.
JMP Securities, LLC
▇.▇. ▇▇▇▇▇▇▇▇▇▇ & Co., LLC

Total

Sch A-1

SCHEDULE B-1

Pricing Terms

1. The Company is selling [—] Ordinary Shares.

2. The Company has granted an option to the Underwriters, severally and not jointly, to purchase up to an additional [—] Ordinary Shares.

3. The initial public offering price per share for the Securities shall be $[—].

Sch B-1-1

SCHEDULE B-2

Free Writing Prospectuses

[—]

Sch B-2-1

SCHEDULE B-3

Written Testing-the-Waters Communications

Investor Presentations used in testing the waters meetings in July and September 2014.

Sch B-3-1

SCHEDULE C

List of Persons and Entities Subject to Lock-up

[—]

Sch C-1

Exhibit A

Form of Lock-Up Agreement

ProQR Therapeutics B.V.

, 2014

Leerink Partners LLC

Deutsche Bank Securities Inc.

As Representatives of the Several Underwriters

c/o Leerink Partners LLC

▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇

▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇

▇▇▇

and

c/o Deutsche Bank Securities Inc.

▇▇ ▇▇▇▇ ▇▇▇▇▇▇

▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

▇▇▇

Re: Proposed Public Offering by ProQR Therapeutics B.V.

Ladies and Gentlemen:

The undersigned is a holder of ordinary shares, a member of the supervisory board or management board, and/or a member of senior management of ProQR Therapeutics B.V., a private company with limited liability (besloten vennootschap met beperkte aansprakelijkheid) organized under the laws of the Netherlands (to be converted to and to change its name to ProQR Therapeutics N.V., a public company with limited liability (naamloze vennootschap), prior to the consummation of the Public Offering (as defined below)) (the “Company”). The undersigned understands that Leerink Partners LLC (“Leerink”) and Deutsche Bank Securities Inc. (“DB”, and together with Leerink, the “Representatives”) propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with the Company providing for the public offering (the “Public Offering”) of the ordinary shares of the Company (the “Ordinary Shares”). In recognition of the benefit that such an offering will confer upon the undersigned, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with each underwriter to be named in the Underwriting Agreement (collectively, the “Underwriters”) that, during the period beginning on the date hereof and ending on the date that is 180 days from the date of the Underwriting Agreement (the “Lock-Up Period”), the undersigned will not, without the prior written consent of the Representatives, directly or indirectly, (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of, or otherwise dispose of or transfer any Ordinary Shares or any securities convertible into or

A-1

exchangeable or exercisable for Ordinary Shares, including depository receipts of the Company, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition (collectively, the “Lock-Up Securities”), or exercise any right with respect to the registration of any of the Lock-Up Securities, or file or cause to be filed any registration statement in connection therewith, under the Securities Act of 1933, as amended, or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Lock-Up Securities, whether any such swap or transaction is to be settled by delivery of Ordinary Shares or other securities, in cash or otherwise. If the undersigned is a member of the supervisory board, management board or senior management of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any issuer directed Ordinary Shares the undersigned may purchase in the Public Offering (including pursuant to a directed share program).

If the undersigned is a member of the supervisory board, management board or senior management of the Company, (1) the Representatives agree 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 the Lock-Up Securities, the Representatives will notify the Company of the impending release or waiver, and (2) the Company will agree or has agreed in the Underwriting Agreement to announce the impending release or waiver by press release through a major news service or as otherwise permitted under FINRA Rule 5131 at least two business days before the effective date of the release or waiver. Any release or waiver granted by the Representatives hereunder to any such person shall only be effective two business days after the date of such publication. The provisions of this paragraph will not apply if (i) the release or waiver is effected solely to permit a transfer not for consideration and (ii) 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.

Notwithstanding the foregoing, and subject to the conditions below, the undersigned may transfer the Lock-Up Securities during the Lock-Up Period without the prior written consent of the Representatives, provided that (1) in the case of clauses (i), (ii), (iii), (iv), (v) and (vi) below, the Representatives receive a signed agreement for the balance of the Lock-Up Period from each donee, trustee, distributee, or transferee, as the case may be, stating that such person is receiving and holding the Lock-Up Securities subject to the provisions of this lock-up agreement, (2) in the case of clauses (i), (ii), (iii), (iv), (v) and (vi), any such transfer shall not involve a disposition for value, (3) in the case of clauses (i), (ii), (iii), (vi) and (vii) below, such transfers are not required to be reported with the U.S. Securities and Exchange Commission (“SEC”) and do not trigger any filing or reporting obligation or require any public announcement during the Lock-Up Period under any other applicable laws, and (4) in the case of clauses (i), (ii), (iii), (vi) and (vii) below, the undersigned does not otherwise voluntarily effect any public filing or report regarding such transfers during the Lock-Up Period:

(i)

as a bona fide gift or gifts; or

(ii)

to any trust or limited family partnership for the direct or indirect benefit of the undersigned or the immediate family of the undersigned or to any entity directly or indirectly wholly owned by the undersigned or the immediate family of the

A-2

undersigned (for purposes of this lock-up agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin); or

(iii)

as a distribution to partners, members, other shareholders or other equity holders of the undersigned (or their equivalents under the jurisdiction of the organization of the undersigned) or, if the undersigned is a trust, to the beneficiaries of the undersigned; or

(iv)

by will, other testamentary document or intestate succession to the legal representative, heir, beneficiary or a member of the immediate family of the undersigned upon the death of the undersigned; or

(v)

by operation of law, including domestic relations orders; or

(vi)

to the undersigned’s affiliates or to any investment fund or other entity controlled or managed by, or under common control or management by, or any investment fund or other entity that controls or manages, the undersigned; or

(vii)

in connection with the exercise, including by “net” exercise, of any options or warrants to acquire Ordinary Shares or the conversion of any convertible security into Ordinary Shares, in each case that are referred to or described in the prospectus for the Public Offering, so long as the Ordinary Shares received upon such exercise or conversion shall remain subject to the terms of this lock-up agreement; or

(viii)

in connection with a merger or sale of the Company pursuant to which the shareholders of the Company immediately prior to such transaction own less than 50% of the voting power of the resulting or acquiring corporation or entity after such transaction (it being further understood that this lock-up agreement shall not restrict the undersigned from entering into any agreement or arrangement in connection therewith, including an agreement to vote in favor of, or tender Ordinary Shares or other securities of the Company in, any such transaction or taking any other action in connection with any such transaction).

Furthermore, during the Lock-Up Period, the undersigned may (a) sell Ordinary Shares of the Company purchased by the undersigned in the Public Offering or on the open market following the Public Offering (other than any Company directed Ordinary Shares purchased in the Public Offering by any member of the supervisory board, management board or senior management of the Company), provided that (i) such sales are not required to be reported with the SEC, other than as required by Regulation 13D-G of the Securities Exchange Act of 1934, as amended, (the “Exchange Act”), and do not trigger any filing or reporting obligation or require any public announcement during the Lock-up Period under any other applicable laws and (ii) the undersigned does not otherwise voluntarily effect any public filing or report regarding such sales during the Lock-Up Period, or (b) 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 (i) such 10b5-1 Plan does not provide for the transfer of Ordinary Shares during the Lock-Up Period and (ii) no public announcement or filing under the Exchange Act, if any, is required of or is voluntarily made by or on behalf of the undersigned or the Company regarding the establishment of such 10b5-1 Plan.

A-3

In addition, the restrictions on transfer and disposition of the Lock-Up Securities during the Lock-Up Period shall not apply to the transfer or cancellation of Lock-Up Securities by or to the Stichting ProQR Therapeutics Participation (the foundation holding Ordinary Shares in the capital of the Company for the purpose of the employee stock option plan, hereinafter the “ESOP Foundation”) required for the termination of the ESOP Foundation’s role in connection with the employee stock option plan prior to completion of the Public Offering and, in connection therewith, the conversion of depositary receipts held by participants in the ESOP Foundation into Ordinary Shares, provided that in connection with such conversion the ultimate beneficial ownership of any Ordinary Shares does not change, and the Ordinary Shares received upon such conversion shall remain subject to the terms of this lock-up agreement.

In addition, upon the prior approval of the Representatives, which shall not be unreasonably withheld, the restrictions on transfer and disposition of the Lock-Up Securities during the Lock-Up Period shall not apply to any transfer in connection with the restructuring of the issued share capital of the Company related to rebalancing between holders of Ordinary Shares or between holders of Ordinary Shares and the Company, in connection with a reverse stock split prior to the completion of the Public Offering and only to realize the appropriate share capital and par value of the Ordinary Shares at the time of completion of the Public Offering.

In the event that any holder of 5% or more of the outstanding Ordinary Shares of the Company that is subject to a substantially similar letter agreement entered into by such holder (other than the Company or the undersigned) is released from the restrictions on transfer and disposition contained therein and permitted by the Representatives to sell or otherwise transfer or dispose of all or any percentage of such holder’s Ordinary Shares for value, other than as permitted by this or a substantially similar letter agreement entered into by such holder, the same percentage of Ordinary Shares held by the undersigned shall concurrently therewith be immediately and fully released on the same terms from any remaining restrictions on transfer and disposition set forth herein (the “Pro-rata Release”); provided, however, that such Pro-rata Release shall not be applied unless and until the Representatives have first released from such restrictions and permitted a holder or holders to sell or otherwise transfer or dispose all or a portion of such holders’ Ordinary Shares in an aggregate amount equal to or greater than 1% of the Company’s Ordinary Shares outstanding immediately following the closing of the Public Offering.

The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the Lock-Up Securities except in compliance with the foregoing restrictions.

This lock-up agreement shall automatically terminate, and the undersigned shall be released from its obligations hereunder, upon the earliest to occur, if any, of the following: (i) if, prior to the execution of the Underwriting Agreement, either Leerink and DB, on behalf of the Underwriters, or the Company, advises the other party in writing that it has determined not to proceed with the Public Offering, (ii) the Company files an application to withdraw the registration statement related to the Public Offering, (iii) if the Underwriting Agreement is executed but is terminated prior to the closing of the Public Offering (other than the provisions thereof which survive termination), or (iv) December 31, 2014, in the event that the Underwriting Agreement has not been executed by such date.

A-4

The undersigned hereby represents and warrants that the undersigned has full power, capacity and authority to enter into this lock-up agreement. This lock-up agreement is irrevocable and will be binding on the undersigned and the successors, heirs, personal representatives and assigns of the undersigned.

This lock-up agreement shall be governed by, and construed in accordance with, the laws of the State of New York.

Very truly yours,

Signature

Printed Name of Person Signing

(Indicate capacity of persons signing if signing as custodian or trustee, or on behalf of an entity)

A-5

Exhibit B

FORM OF PRESS RELEASE

TO BE ISSUED PURSUANT TO SECTION 3(j)

[—]

B-1

UNDERWRITING AGREEMENT1

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