Exhibit 1.1

14,300,000 Common Shares

AC IMMUNE SA

UNDERWRITING AGREEMENT

December 15, 2023

c/o Jefferies LLC 

520 Madison Avenue 

New York, New York 10022

c/o Leerink Partners LLC 

1301 Avenue of the Americas, 12^th Floor 

New York, New York 10019

As Representatives of the several Underwriters

Ladies and Gentlemen:

Introductory. AC Immune SA, a company established in Ecublens, Canton of Vaud, Switzerland (the “Company”), proposes to sell to the several underwriters named in Schedule A (the “Underwriters”) an aggregate of 14,300,000 shares of its registered shares, nominal value CHF 0.02 per share (the “Shares”). The 14,300,000 Shares to be sold by the Company are called the “Offered Shares” and shall comprise 14,300,000 newly issued Shares. Jefferies LLC (“Jefferies”) and Leerink Partners LLC (“Leerink Partners”) have agreed to act as representatives of the several Underwriters (in such capacity, the “Representatives”) in connection with the offering and sale of the Offered Shares. To the extent there are no additional underwriters listed on Schedule A, the term “Representatives” as used herein shall mean you, as Underwriters, and the term “Underwriters” shall mean either the singular or the plural, as the context requires.

The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a shelf registration statement on Form F-3, File No. 333-255576, including a base prospectus (the “Base Prospectus”) to be used in connection with the public offering and sale of the Offered Shares. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, in the form in which it became effective under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “Securities Act”), including all documents incorporated or deemed to be incorporated by reference therein and any information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430B under the Securities Act, is called the “Registration Statement.” Any registration statement filed by the Company pursuant to Rule 462(b) under the Securities Act in connection with the offer and sale of the Offered Shares is called the “Rule 462(b) Registration Statement,” and from and after the date and time of filing of any such Rule 462(b) Registration Statement the term “Registration Statement” shall include the Rule 462(b) Registration Statement. As used herein, the term “Prospectus” shall mean the final prospectus supplement to the Base Prospectus that describes the Offered Shares and the offering thereof (the “Final Prospectus Supplement”), together with the Base Prospectus, in the form first used by the Underwriters to confirm sales of the Offered Shares or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act. As used herein, “Applicable Time” is 7:30 a.m. (New York City time) on December 15, 2023. As used herein, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, and “Time of Sale Prospectus” means the Base Prospectus, as amended or supplemented immediately prior to the Applicable Time, together with the free writing prospectuses, if any, identified in Schedule B-1 hereto and the pricing information identified

in Schedule B-2 hereto. As used herein, “Road Show” means a “road show” (as defined in Rule 433 under the Securities Act) relating to the offering of the Offered Shares contemplated hereby that is a “written communication” (as defined in Rule 405 under the Securities Act).

All references in this Agreement to the Registration Statement, any preliminary prospectus, the Base Prospectus and the Prospectus shall include the documents incorporated or deemed to be incorporated by reference therein. All references in this Agreement to financial statements and schedules and other information which are “contained,” “included” or “stated” in, or “part of” the Registration Statement, the Rule 462(b) Registration Statement, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus, and all other references of like import, shall be deemed to mean and include all such financial statements and schedules and other information which is or is deemed to be incorporated by reference in the Registration Statement, the Rule 462(b) Registration Statement, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus, as the case may be. All references in this Agreement to amendments or supplements to the Registration Statement, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus shall be deemed to mean and include the filing of any document under the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “Exchange Act”) that is or is deemed to be incorporated by reference in the Registration Statement, any preliminary prospectus, the Base Prospectus, or the Prospectus, as the case may be. All references in this Agreement to (i) the Registration Statement, any preliminary prospectus, the Base Prospectus or the Prospectus, any amendments or supplements to any of the foregoing, or any free writing prospectus, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“EDGAR”) and (ii) the Prospectus shall be deemed to include any “electronic Prospectus” provided for use in connection with the offering of the Offered Shares as contemplated by Section 5(n) of this Agreement.

The Company hereby confirms its agreements with the Underwriters as follows:

Section 1.Representations and Warranties of the Company. The Company hereby represents, warrants and covenants to each Underwriter, as of the date of this Agreement, and as of the Closing Date (as hereinafter defined), if any, as follows:

(i)Compliance with Registration Requirements. The Registration Statement has become effective under the Securities Act. The Company has complied, to the Commission’s satisfaction, with all requests of the Commission for additional or supplemental information, if any. No stop order suspending the effectiveness of the Registration Statement is in effect and no proceedings for such purpose have been instituted or are pending or, to the best knowledge of the Company, are contemplated or threatened by the Commission. At the time the Company’s Annual Report on Form 20-F for the year ended December 31, 2022 (the “Annual Report”) was filed with the Commission, or, if later, at the time the Registration Statement was originally filed with the Commission, the Company met the then-applicable requirements for use of Form F-3 under the Securities Act. The Company meets the requirements for use of Form F-3 under the Securities Act pursuant to General Instruction I.A. The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the Time of Sale Prospectus and the Prospectus, at the time they were or hereafter are filed with the Commission, or became effective under the Exchange Act, as the case may be, complied and will comply in all material respects with the requirements of the Exchange Act.

(ii)Disclosure. Any preliminary prospectus and the Prospectus when filed complied in all material respects with the applicable provisions of the Securities Act and, if filed by electronic transmission pursuant to EDGAR, was identical (except as may be permitted by Regulation S-T under the Securities Act) to the copy thereof delivered to the Underwriters for use in connection with the offer and sale of the Offered Shares. Each of the Registration Statement and any post-effective amendment thereto,

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at the time it became or becomes effective, complied and will comply in all material respects with the applicable provisions of the Securities Act and did not and will not contain any 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. As of the Applicable Time, the Time of Sale Prospectus did not, and at the Closing Date (as defined in Section 2), will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. The Prospectus, as of its date, did not, and at the Closing Date, will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties set forth in the three immediately preceding sentences do not apply to statements in or omissions from the Registration Statement or any post-effective amendment thereto, or the Prospectus or the Time of Sale Prospectus, or any amendments or supplements thereto, made in reliance upon and in conformity with written information relating to any Underwriter furnished to the Company in writing by the Representatives expressly for use therein, it being understood and agreed that such information only consists of the information described in Section 11(b) below. There are no contracts or other documents required to be described in the Time of Sale Prospectus or the Prospectus or to be filed as an exhibit to the Registration Statement which have not been described or filed as required.

(iii)Free Writing Prospectuses; Road Show. As of the determination date referenced in Rule 164(h) under the Securities Act, the Company was not, is not or will not be (as applicable) an “ineligible issuer” in connection with the offering of the Offered Shares pursuant to Rules 164, 405 and 433 under the Securities Act. Each free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of Rule 433 under the Securities Act, including timely filing with the Commission or retention where required and legending, and each such free writing prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Offered Shares did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, the Prospectus or any preliminary prospectus and not superseded or modified. Except for the free writing prospectuses, if any, identified in Schedule B-1, and electronic road shows, if any, furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior written consent (which consent shall not be unreasonably withheld), prepare, use or refer to, any free writing prospectus. Each Road Show, when considered together with the Time of Sale Prospectus, did not, as of the Applicable Time, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(iv)Distribution of Offering Material by the Company. Prior to the completion of the Underwriters’ distribution of the Offered Shares, the Company has not distributed, and will not distribute, any offering material in connection with the offering and sale of the Offered Shares other than the Registration Statement, the Time of Sale Prospectus, the Prospectus or any free writing prospectus reviewed and consented to by the Representatives (which consent shall not be unreasonably withheld), and the free writing prospectuses, if any, identified on Schedule B hereto.

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

(vi)Authorization of the Offered Shares. The Offered Shares, when registered with the Commercial Register of the Canton of Vaud and issued and delivered by the Company against payment

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therefor pursuant to this Agreement, will be duly authorized for issuance and sale pursuant to this Agreement, validly issued, fully paid-in and nonassessable, and, other than as expressly set forth in this Agreement or the Time of Sale Prospectus or the Prospectus, the issuance and sale of the Offered Shares is not subject to any pre-emptive rights, rights of first refusal or other similar rights to subscribe for or purchase the Offered Shares.

(vii)No Applicable Registration or Other Similar Rights. Except as disclosed in the Time of Sale Prospectus and the Prospectus, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to a Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Securities Act (collectively, “registration rights”), and any person to whom the Company has granted registration rights has agreed not to exercise such rights until after the expiration of the Lock-Up Period referred to in Section 5(p) hereof.

(viii)No Material Adverse Change in Business. Except as disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus, since the end of the period covered by the latest audited financial statements included in the Registration Statement, the Time of Sale Prospectus and the Prospectus, (i) there has been no change in the condition (financial or otherwise), results of operations, business, properties or prospects of the Company that is material and adverse, (ii) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock and (iii) there has been no material adverse change in the capital stock, short-term indebtedness, long-term indebtedness, net current assets or net assets of the Company (any such change being referred to herein as a “Material Adverse Change”).

(ix)Independent Accountants. PricewaterhouseCoopers SA, which has expressed its opinion with respect to the financial statements (which term as used in this Agreement includes the related notes thereto) filed with the Commission as a part of the Registration Statement, the Time of Sale Prospectus and the Prospectus, was, at the time of expressing such opinion, (i) an independent registered public accounting firm as required by the Securities Act, the Exchange Act, and the rules of the Public Company Accounting Oversight Board (“PCAOB”), (ii) in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X under the Securities Act, (iii) a registered public accounting firm as defined by the PCAOB whose registration has not been suspended or revoked and who has not requested such registration to be withdrawn and (iv) an independent qualified public accountant qualified under the applicable provisions of the CO, the Swiss Audit Supervision Act (Revisionsaufsichtsgesetz) and any ordinances promulgated thereunder.

(x)Financial Statements. The consolidated financial statements included or incorporated by reference in each Registration Statement, the Time of Sale Prospectus and the Prospectus present fairly in all material respects the consolidated financial position of the Company and its subsidiaries as of the dates shown and consolidated results of operations and cash flows for the periods shown, and such consolidated financial statements have been prepared in conformity with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (the “IASB”) applied on a consistent basis.

(xi)Internal Controls and Compliance with Sarbanes-Oxley. The Company and the Company’s Board of Directors (the “Board”) are in compliance with the applicable provisions of Sarbanes-Oxley Act of 2002 (“Sarbanes-Oxley”) and the Exchange Act. The Company maintains a system of internal controls, including, but not limited to, disclosure controls and procedures, internal controls over accounting matters and financial reporting, an internal audit function and legal and

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regulatory compliance controls (collectively, “Internal Controls”) that are designed to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorization, (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with IFRS as issued by the ISAB and to maintain accountability for assets, (iii) access to assets is permitted only in accordance with management’s general or specific authorization, (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences and (v) the interactive data in the eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the Time of Sale Prospectus and the Prospectus fairly presents the information called for in all material respects and is prepared in accordance with the Commission’s rules and guidelines thereto. The Internal Controls are overseen by the Audit & Finance Committee (the “Audit & Finance Committee”) of the Board in accordance with Exchange Act. Except as disclosed in the Time of Sale Prospectus and the Prospectus, the Company has not publicly disclosed or reported to the Audit & Finance Committee or the Board, and within the next 135 days the Company does not reasonably expect to publicly disclose or report to the Audit & Finance Committee or the Board, a significant deficiency, material weakness, adverse change in Internal Controls or fraud involving management or other employees who have a significant role in Internal Controls, any violation of, or failure to comply with, Sarbanes-Oxley, the Exchange Act and the rules of The Nasdaq Global Market (“Nasdaq”), or any matter which, if determined adversely, would have a Material Adverse Change.

(xii)Incorporation of the Company. The Company has been duly incorporated and is duly organized and validly existing under the laws of Switzerland, with full power and authority (corporate and other) to own its properties and conduct its business as described in the Registration Statement, the Time of Sale Prospectus and the Prospectus.

(xiii)Subsidiaries. The Company’s only subsidiary (as defined in Rule 405 under the Securities Act) is AC Immune USA, Inc.

(xiv)Capitalization and Other Capital Stock Matters. As of September 30, 2023, the issued and outstanding share capital and the authorized share capital as well as the conditional share capital of the Company are as set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus under the caption “Capitalization” (other than for subsequent issuances, if any, pursuant to employee benefit plans, pursuant to the Company’s existing “at the market” program or upon the exercise of outstanding options or warrants, in each case described in the Registration Statement, the Time of Sale Prospectus and the Prospectus). The Shares (including the Offered Shares) conform in all material respects to the description thereof contained in the Time of Sale Prospectus. All of the issued and outstanding Shares have been duly authorized and validly issued, are fully paid and nonassessable and have been issued in compliance with all federal and state securities laws and the Federal Act on the Amendment of the Swiss Civil Code Part Five: The Code of Obligations (the “CO”). None of the outstanding Shares was issued in violation of any pre-emptive rights, rights of first refusal or other similar rights to subscribe for or purchase securities of the Company. There are no authorized or outstanding options, warrants, pre-emptive rights, rights of first refusal or other rights to purchase, or equity or debt securities or other rights convertible into or exchangeable or exercisable for, any capital stock of the Company other than those described in the Registration Statement, the Time of Sale Prospectus and the Prospectus. The descriptions of the Company’s stock option, stock bonus and other stock plans or similar arrangements, and the options or other rights granted thereunder, set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus accurately and fairly presents the information required to be shown with respect to such plans, arrangements, options and rights.

(xv)Stock Exchange Listing. The Shares are registered pursuant to Section 12(b) or 12(g) of the Exchange Act and are listed on Nasdaq, and the Company has taken no action designed to, or likely to

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have the effect of, terminating the registration of the Shares under the Exchange Act or delisting the Shares from Nasdaq, nor has the Company received any notification that the Commission or Nasdaq is contemplating terminating such registration or listing. To the Company’s knowledge, it is in compliance with all applicable listing requirements of Nasdaq.

(xvi)Absence of Further Requirements. No consent, approval, authorization, or order of, or filing or registration with, any person (including any governmental agency or body or any court) is required for the consummation of the transactions contemplated by this Agreement in connection with the offering, the issuance and sale of the Offered Shares by the Company, except such as have been obtained or made and such as may be required under state securities laws or except such as would not reasonably be expected to result in a material adverse effect on the condition (financial or otherwise), results of operations, business, properties or prospects of the Company (a “Material Adverse Effect”).

(xvii)Absence of Defaults and Conflicts Resulting from Transaction. The execution, delivery and performance of this Agreement, and the issuance and sale of the Offered Shares will not result in a breach or violation of any of the terms and provisions of, or constitute a default or a Debt Repayment Triggering Event (as defined below) under, or result in the, imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to, (i) the articles of association or other similar organizational documents of the Company, (ii) any statute, rule, regulation or order of any governmental agency or body or any court, domestic or foreign, having jurisdiction over the Company or any of its properties, or (iii) any agreement or instrument to which the Company is a party or by which the Company is bound or to which any of the properties of the Company is subject except for purposes of clauses (ii) and (iii) where any such breach, violation, default, lien, charge or encumbrance would not reasonably be expected to have a Material Adverse Effect. As used herein, “Debt Repayment Triggering Event” means any event or condition that gives, or with the giving of notice or lapse of time would give, the holder of any note, debenture, or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company.

(xviii)Absence of Existing Defaults and Conflicts. The Company is not in violation of its articles of association or similar organizational documents or in default (or with the giving of notice or lapse of time would be in default) under any existing obligation, agreement, covenant or condition contained in any indenture, loan agreement, mortgage, lease or other agreement or instrument to which it is a party or by it is bound or to which any its properties is subject, except such defaults that would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(xix)Compliance with Laws. The Company has been and is in compliance with all applicable laws, rules and regulations, except where failure to be so in compliance could not be expected, individually or in the aggregate, to have a Material Adverse Effect.

(xx)Litigation. Except as disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus, there are no pending actions, suits or proceedings (including any inquiries made to the Company or, to the Company’s knowledge, investigations by any court or governmental agency or body, domestic or foreign) against or affecting the Company or any of its properties that, if determined adversely to the Company, would individually or in the aggregate have a Material Adverse Effect, or would materially and adversely affect the ability of the Company to perform its obligations under this Agreement, or which are otherwise material in the context of the sale of the Offered Shares; and no such actions, suits or proceedings (including any inquiries or investigations by any court or governmental agency or body, domestic or foreign) are, to the Company’s knowledge, threatened or contemplated.

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(xxi)Absence of Labor Dispute. No labor dispute with the employees of the Company exists or, to the knowledge of the Company, is imminent that would reasonably be expected to have a Material Adverse Effect.

(xxii)Intellectual Property Rights. The Company owns, possesses or can acquire on reasonable terms all trademarks, trade names, patent rights, copyrights, domain names, licenses, trade secrets, inventions, technology, know-how and other intellectual property and similar proprietary rights, including registrations and applications for registration thereof (collectively, “Intellectual Property Rights”) described in the Time of Sale Prospectus and, to the knowledge of the Company and except as disclosed in the Time of Sale Prospectus and the Prospectus, owns all Intellectual Property Rights necessary or material to the conduct of the business now conducted or proposed in the Time of Sale Prospectus to be conducted by it. Except in the case of clauses (i)–(iv) below as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, (i) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by any third party against the Company challenging the Company’s rights in or to any of the Company’s Intellectual Property Rights, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (ii) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others against the Company challenging the validity, enforceability or scope of any Intellectual Property Rights owned by the Company, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (iii) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim against the Company by any third party that the Company infringes, misappropriates or otherwise violates any Intellectual Property Rights or other proprietary rights of such third party and the Company is unaware of any other fact which would form a reasonable basis for any such claim; and (iv) all assignments of intellectual property from the Company’s employees and consultants to the Company are valid, binding and enforceable and, to the Company’s knowledge, have appropriately vested ownership in the Company of any work product, developments or the like that is subject to such assignments.

(xxiii)Possession of Licenses and Permits. The Company possesses, and is in compliance with the terms of, all adequate certificates, authorizations, franchises, licenses and permits, including, without limitation, from the U.S. Food and Drug Administration (“FDA”) and equivalent foreign regulatory authorities (“Licenses”) necessary or material to the conduct of the business now conducted or proposed in the Registration Statement, the Time of Sale Prospectus or the Prospectus to be conducted by it and has not received any notice of proceedings or other correspondence relating to the revocation or modification of any Licenses that, if determined adversely to the Company, would individually or in the aggregate reasonably be expected to have a Material Adverse Effect.

(xxiv)Title to Property. The Company does not own any real property. Except as disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus, the Company has good and marketable title to all other material properties and assets owned by it, in each case free from liens, charges, encumbrances and defects that would reasonably be expected to have a Material Adverse Effect and, except as disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus, the Company holds any leased real or personal property under valid and enforceable leases with no terms or provisions that would reasonably be expected to have a Material Adverse Effect.

(xxv)Tax Law Compliance. The Company has filed all federal, state, local and non-U.S. tax returns that are required to be filed by it or has requested extensions thereof (except in any case in which the failure so to file would not have a Material Adverse Effect); and except as disclosed in the Time of Sale Prospectus and the Prospectus, the Company has paid all taxes (including any assessments, fines or penalties) shown as due thereon, except for any such taxes, assessments, fines or penalties currently being contested in good faith or as would not, individually or in the aggregate, have a Material Adverse Effect.

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(xxvi)Insurance. The Company is insured by insurers with appropriately rated claims paying abilities against such losses and risks and in such amounts as the Company reasonably considers prudent and customary for the businesses in which it is engaged; all material policies of insurance and fidelity or surety bonds insuring the Company or its business, asset, employees, officers and directors are in full force and effect; the Company is in compliance with the terms of such policies and instruments in all material respects; and there are no claims by the Company under any such policy or instrument as to which any insurance company is denying liability or defending under a reservation of rights clause; the Company has not been refused any material insurance coverage sought or applied for; and the Company has no reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not reasonably be expected to have a Material Adverse Effect.

(xxvii) Compliance with Environmental Laws. The Company is not in violation of any statute, any rule, regulation, decision or order of any governmental agency or body or any court, domestic or foreign, relating to the use, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “environmental laws”), owns or operates any real property contaminated with any substance that is subject to any environmental laws, is liable for any off-site disposal or contamination pursuant to any environmental laws, or is subject to any claim relating to any environmental laws, which violation, contamination, liability or claim would individually or in the aggregate reasonably be expected to have a Material Adverse Effect; and the Company is not aware of any pending investigation which might lead to such a claim.

(xxviii)    Investment Company Act. The Company is not and, after giving effect to the offering and sale of the Offered Shares and the application of the proceeds thereof as described in the Registration Statement, the Time of Sale Prospectus or the Prospectus, will not be an “investment company” as defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(xxix)Absence of Manipulation. The Company has not taken, directly or indirectly, any action that is designed to or that has constituted or that would reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Offered Shares.

(xxx)Absence of Market Abuse. The Company has not taken, directly or indirectly, in relation to the offering of the Offered Shares or otherwise, any action or engaged in any course of conduct in breach of, and has taken adequate measures and has adequate procedures in place in order to ensure compliance with, and none of the issue and sale of the Offered Shares and the consummation of the transactions contemplated by this Agreement will constitute a violation by the Company of, any applicable European Union, Swiss, United States or any other relevant jurisdiction “insider dealing,” “insider trading” or similar legislation and, so far as the Company is aware, no person acting on its behalf has breached or is in breach of any relevant market abuse or insider trading law or regulation, including any reporting obligations to the Commission or any other authority. Neither the Company nor any person acting on its or their behalf (which, for the avoidance of doubt, shall not include the Underwriters or their affiliates or persons acting on their behalf, as to whom no representation, warranty or undertaking is given), has taken or omitted to take any action nor will take any action or omit to take any action which may result in the loss by any of the Underwriters of the ability to rely on any stabilization safe harbor.

(xxxi)Related-Party Transactions. There are no business relationships or related-party transactions involving the Company or any other person required to be described in the Registration Statement, the Time of Sale Prospectus or the Prospectus that have not been described as required.

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(xxxii)FINRA Matters. All of the information provided to the Underwriters or to counsel for the Underwriters by the Company and, to the Company’s knowledge, its officers and directors and the holders of any securities (debt or equity) of the Company or options to acquire any securities of the Company in connection with the offering of the Offered Shares is true, complete, correct and compliant with the Financial Industry Regulatory Authority, Inc.’s (“FINRA”) rules and any letters, filings or other supplemental information provided to FINRA pursuant to FINRA Rules or NASD Conduct Rules is true, complete and correct.

(xxxiii)Statistical and Market-Related Data. Any third-party statistical and market-related data included in the Registration Statement, the Time of Sale Prospectus or the Prospectus or any written testing-the-waters communication are based on or derived from sources that the Company believes to be reliable and accurate.

(xxxiv)No Unlawful Contributions or Other Payments. Neither the Company nor, to the best of the Company’s knowledge, any employee or agent of the Company, has made any contribution or other payment to any official of, or candidate for, any federal, state or foreign office in violation of any law or of the character required to be disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus.

(xxxv)Foreign Corrupt Practices Act. Neither the Company nor, to the knowledge of the Company, any director, officer, agent, employee, affiliate or other person acting on behalf of the Company has, in the course of its actions for, or on behalf of, the Company (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expenses relating to political activity; (ii) made any direct or indirect unlawful payment to any domestic government official, “foreign official” (as defined in the U.S. Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (collectively, the “FCPA”) or employee from corporate funds; (iii) violated or is in violation of any provision of the FCPA or any applicable non-U.S. anti-bribery statute or regulation; or (iv) made any unlawful bribe, rebate, payoff, influence payment, kickback or other unlawful payment to any domestic government official, such foreign official or employee; and the Company and, to the knowledge of the Company, the Company’s affiliates have conducted their respective businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith.

(xxxvi)      Money Laundering Laws. The operations of the Company are, and have been conducted at all times, in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar applicable rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company, threatened.

(xxxvii)    Sanctions. Neither the Company nor, to the knowledge of the Company, after due inquiry, any director, officer, agent, employee, affiliate or person acting on behalf of the Company is currently subject to any sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”) or the U.S. Department of State, the United Nations Security Council, the European Union, His Majesty’s Treasury of the United Kingdom, the State Secretariat for Economic Affairs of Switzerland or other relevant sanctions authority (collectively, “Sanctions”); and the Company will not directly or indirectly use the proceeds of this offering, or lend, contribute or otherwise make available such proceeds to any joint venture partner or other person or entity, for the purpose of financing the activities of or business with any person, or in any country or territory, that currently is the subject to

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any 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.

(xxxviii)       No Finder’s Fee. Except as disclosed in the Registration Statement, the Time of Sale Prospectus or the Prospectus, there are no contracts, agreements or understandings between the Company and any person that would give rise to a valid claim against the Company or any Underwriter for a brokerage commission, finder’s fee or other like payment in connection with this offering.

(xxxix)        [Reserved].

(xl)[Reserved].

(xli)Clinical Trials. The preclinical and clinical studies conducted by the Company, and to the knowledge of the Company, the preclinical and clinical studies conducted on behalf of, or sponsored by, the Company, that are described in, or the results of which are referred to in, the Time of Sale Prospectus and the Prospectus were and, if still pending, are being conducted in all material respects in accordance with protocols, procedures and controls filed with the appropriate regulatory authorities for each such test or study, as the case may be, and with standard medical and scientific research procedures, except in each case where failure to so conduct would not reasonably be expected to have a Material Adverse Effect; each description of the results of such studies contained in the Time of Sale Prospectus and the Prospectus 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 or tests the results of which are inconsistent with, or otherwise call into question, the results described or referred to in the Time of Sale Prospectus and the Prospectus; the Company has not received any notices or other correspondence from the FDA or any committee thereof or from any other U.S. or foreign government or regulatory authority (collectively, the “Regulatory Authorities”) requiring the termination, suspension or material modification of any preclinical or clinical studies that are described or referred to in the Time of Sale Prospectus or the Prospectus, other than ordinary course communications with respect to modifications in connection with the design and implementation of such studies; and the Company has operated and currently is in compliance in all respects with all applicable rules, regulations and policies of the Regulatory Authorities except as would not reasonably be expected to have a Material Adverse Effect.

(xlii)Healthcare Regulatory Compliance. Except as would not reasonably be expected to have a Material Adverse Effect, the Company has operated and is currently in compliance with all applicable Health Care Laws (defined herein), and has not engaged in activities which are, as applicable, cause for false claims liability, civil penalties, or mandatory or permissive exclusion from Medicare, Medicaid, or any other state or federal health care program. For purposes of this Agreement, “Health Care Laws” shall mean the Federal Food, Drug, and Cosmetic Act (21 U.S.C. §§ 301 et seq.); the federal Anti-Kickback Statute (42 U.S.C. § 1320a-7b(b)); the civil False Claims Act (31 U.S.C. §§ 3729 et seq.); the criminal False Claims Act (42 U.S.C. § 1320a-7b(a)); all criminal laws relating to health care fraud and abuse, including but not limited to 18 U.S.C. Sections 286, 287, 1035, 1347 and 1349, and the health care fraud criminal provisions under the Health Insurance Portability and Accountability Act of 1996 (42 U.S.C. § 1320d et seq.) (“HIPAA”); the exclusion laws (42 U.S.C. § 1320a-7); the civil monetary penalties law (42 U.S.C. § 1320a-7a); the Physician Payment Sunshine Act (42 U.S.C. § 1320a-7h); HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act (42 U.S.C. §§ 17921 et seq.); the Medicare statute (Title XVIII of the Social Security Act); the Medicaid statute (Title XIX of the Social Security Act); the regulations promulgated pursuant to such laws and any other similar local, state or federal law and regulations. The Company has not received any U.S. Food and Drug Administration (“FDA”) Form 483, notice of adverse finding, warning letter, untitled letter or other correspondence, communication or notice from the U.S. Food and Drug Administration or any other governmental or regulatory authority alleging or asserting material noncompliance with any Health Care Laws, and, to the

10 

Company’s knowledge, no claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action is threatened. The Company is not a party to nor does it have any ongoing reporting obligations pursuant to any corporate integrity agreements, deferred prosecution agreements, monitoring agreements, consent decrees, settlement orders, plans of correction or similar agreements with or imposed by any governmental or regulatory authority. The Company, or any of its employees, officers, directors or agents has not been excluded, suspended or debarred from participation in any U.S. federal health care program or human clinical research, or, to the Company’s knowledge, is subject to a governmental inquiry, investigation, proceeding, or other similar action that would reasonably be expected to result in debarment, suspension or exclusion.

(xliii)Healthcare Product Manufacturing. The manufacture of the Company’s clinical products and product candidates by or on behalf of the Company is being conducted in compliance in all material respects with all applicable Good Manufacturing Practices standards, and to the extent of any US clinical trials on Company products, with all applicable Health Care Laws, including, without limitation, the FDA’s current good manufacturing practice regulations at 21 CFR Part 820, and, to the extent applicable to clinical trials on Company products outside of the United States, the respective counterparts thereof promulgated by governmental authorities in countries outside the United States. The Company has not had any manufacturing site (whether Company-owned or, to the Company’s knowledge, that of a third party manufacturer for the Company’s product candidates) subject to a governmental authority (including FDA or the European Medicines Agency “EMA”) shutdown or import or export prohibition, nor received any FDA, EMA or other governmental authority “warning letters,” or “untitled letters” alleging or asserting material noncompliance with any applicable Health Care Laws, requests to make material changes to the Company’s product candidates, processes or operations, or similar correspondence or notice from the FDA, EMA or other governmental authority alleging or asserting material noncompliance with any applicable Health Care Laws, other than those that have been satisfactorily addressed and/or closed with the FDA, EMA or other governmental authority. To the knowledge of the Company, neither the FDA, EMA or any other governmental authority is considering such action.

(xliv)No Imminent Insolvency, Overindebtedness or Capital Loss. The Company is not subject to imminent insolvency within the meaning of article 725 CO and is not overindebted within the meaning of article 725b CO. The Company is not suffering from capital loss within the meaning of article 725a CO.

(xlv)Cybersecurity. Except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect: (i) the Company’s information technology assets and equipment, computers, systems, networks, hardware, software, websites, applications, and databases (collectively, “IT Systems”) are adequate for, and operate and perform in all respects as required in connection with, the operation of the business of the Company as currently conducted, to the Company’s knowledge, free and clear of all bugs, errors, defects, Trojan horses, time bombs, malware and other corruptants; (ii) the Company has implemented and maintained commercially reasonable physical, technical and administrative controls, policies, procedures, and safeguards to maintain and protect their confidential information and the integrity, continuous operation, redundancy and security of all IT Systems and data, including Personal Data (as defined hereinafter) used in connection with their businesses (“Personal Data” means (A) a natural person’s name, street address, telephone number, e-mail address, photograph, social security number or tax identification number, driver’s license number, passport number, credit card number, bank information, or customer or account number; (B) any information which would qualify as “personally identifying information” under the Federal Trade Commission Act, as amended; (C) “personal data” as defined by the European Union General Data Protection Regulation 2016/679; or (D) any information which would qualify as “protected health information” under the Health Insurance Portability and Accountability Act of 1996, as amended by the Health Information Technology for Economic and Clinical Health Act); (iii) to the Company’s knowledge, there have been no breaches, violations, outages or unauthorized uses of or accesses to same, except for those that have been remedied

11 

without cost or liability or the duty to notify any other person, nor any incidents under internal review or investigations relating to the same; and (iv) the Company is presently in compliance with all applicable laws or statutes, including all applicable state and federal data privacy and security laws and regulations, and all judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, internal policies and contractual obligations relating to the privacy and security of IT Systems and Personal Data and to the protection of such IT Systems and Personal Data from unauthorized use, access, misappropriation or modification.

(xlvi)No Actions. On the date hereof, the Commercial Register has not been blocked and no challenge of the resolutions of the Company's Board of Directors and no other action, complaint or dispute (each, an “Action”) is pending and, to the best of the Company's knowledge, no Action has been publicly announced or credibly threatened, in each case against or in connection with the transactions contemplated under this Agreement or their consummation; and no laws or regulations and no decision, order, injunction or decree of any court, arbitral tribunal, authority or administrative or regulatory body or commission or exchange exists that has or may have the effect of making illegal or otherwise preventing or prohibiting, or that seeks to enjoin, restrain, impede or levy a substantial difficulty on the transactions contemplated under this Agreement or their consummation.

Any certificate signed by any officer of the Company and delivered to any Underwriter or to counsel for the Underwriters in connection with the offering, or the purchase and sale, of the Offered Shares shall be deemed a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

The Company has a reasonable basis for making each of the representations set forth in this Section 1. The Company acknowledges that the Underwriters and, for purposes of the opinions to be delivered pursuant to Section 8 hereof, counsel to the Company and counsel to the Underwriters, will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

Section 2.Purchase, Sale and Delivery of the Offered Shares.

(a)The Offered Shares. Upon the terms herein set forth, the Company agrees to issue and sell to the several Underwriters an aggregate of 14,300,000 Offered Shares. On the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Underwriters agree, severally and not jointly, to purchase from the Company on the Closing Date (as defined below) the respective number of Offered Shares set forth opposite their names on Schedule A. The purchase price per Offered Share to be paid by the several Underwriters to the Company shall be $3.29 per share.

(b)The Closing Date. Delivery of the Offered Shares to the Underwriters and payment for the Offered Shares shall be made at the offices of Paul Hastings LLP (or such other place as may be agreed to by the Company and the Representatives) at 9:00 a.m. New York City time, on December 19, 2023, or such other time and date as the Representatives shall designate by notice to the Company (the time and date of such closing is called the “Closing Date”), and otherwise in accordance with Section 2(d) and Section 2(e). The Company hereby acknowledges that circumstances under which the Representatives may provide notice to postpone the Closing Date as originally scheduled include, but are not limited to, any determination by the Company or the Representatives to recirculate to the public copies of an amended or supplemented Prospectus or a delay as contemplated by the provisions of Section 11(d).

(c)Public Offering of the Offered Shares. The Representatives hereby advise the Company that the Underwriters intend to offer for sale to the public in the United States, initially on the terms set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus, their respective

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portions of the Offered Shares as soon after this Agreement has been executed as the Representatives, in their sole judgment, have determined is advisable and practicable.

(d)Payment for the Offered Shares. Payment for the Offered Shares shall be made at the Closing Date by wire transfer of immediately available funds to the order of the Company. It is understood that the Representatives have been authorized, for their own accounts and the accounts of the several Underwriters, to accept delivery of and receipt for the Offered Shares, and make payment of the purchase price for the Offered Shares the Underwriters have agreed to purchase. Jefferies individually, not as the Representative of the Underwriters, may (but shall not be obligated to) make payment for any Offered Shares to be purchased by any Underwriter whose funds shall not have been received by the Representatives by the Closing Date for the account of such Underwriter, but any such payment shall not relieve such Underwriter from any of its obligations under this Agreement.

(e)Delivery of the Offered Shares. The Company shall deliver, or cause to be delivered to the Representatives for the accounts of the several Underwriters, through the facilities of The Depositary Trust Company, the Offered Shares in uncertificated form at the Closing Date, against release of a wire transfer of immediately available funds for the amount of the purchase price for the Offered Shares, with any transfer taxes payable in connection with the delivery of the Offered Shares to the Representatives for the accounts of the several Underwriters duly paid by the Representatives. The Offered Shares shall be registered in such names and denominations as the Representatives shall have requested at least one full business day prior to the Closing Date. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriters.

(f)Board Resolutions prior to Execution of this Agreement. The Company confirms that the Board or its relevant committee has (in case of a committee, based on a valid and appropriate delegation by the Board), on or prior to the date hereof, taken appropriate resolutions to implement and complete the transactions contemplated hereunder, in particular (i) to authorize the execution of, and the performance by the Company of its obligations under, this Agreement; (ii) to authorize the issuance of the Offered Shares as contemplated by this Agreement; (iii) to determine the size of any issuance and the price per Offered Shares; and (iv) to approve the Final Prospectus Supplement.

Section 3.Capital Increase and the Delivery of Offered Shares.

(a)Capital Increase. The Company confirms that

(i)the Company’s articles of association authorize the Board to effect a share capital increase in a maximum amount of CHF 400,000.00 by issuing up to 20,000,000 Shares, whereby the statutory pre-emptive rights of the existing shareholders of the Company may be excluded, such authorization having been granted by resolution of the ordinary shareholders' meeting held on June 24, 2022 (the “Shareholders’ Resolution”); and

(ii)on December 11, 2023 the Board has resolved on an increase of the share capital of the Company (Durchführungsbeschluss) from CHF 1,794,907.30 by an amount of up to CHF 330,000 by issuing up to 16,500,000 new Shares, at an issue price of CHF 0.02 per Share, to be fully paid in in cash, from the Company’s authorized share capital, whereby all statutory pre-emptive rights to which the shareholders of the Company are entitled under Swiss law have been validly excluded.

(b)Board Resolution and Registration of Capital Increase. Before 3:00 a.m. New York City time on the last business day immediately preceding the Closing Date, or such other time and date as agreed between the Company and the Representatives, the Board (or a committee or a Board member duly authorized by the Board) will:

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(i)adopt a report (Kapitalerhöhungsbericht) on the authorized capital increase of the Company from CHF 1,794,907.30 by an amount of CHF 286,000 by issuing 14,300,000 new Shares, at an issue price of CHF 0.02 per Share (“Capital Increase”), in accordance with Swiss statutory law;

(ii)resolve in the form of a duly notarized deed on the Capital Increase and make all amendments to the articles of association of the Company necessary in connection with the Capital Increase (Feststellungs- und Statutenänderungsbeschluss); and

(iii)promptly thereafter, but no later than 3:00 a.m. New York City time on the last business day immediately preceding the Closing Date, file the documents necessary for the registration of the Capital Increase with the Commercial Register of the Canton of Vaud;

(c)Delivery of Offered Shares. As soon as practicable after the registration of the Capital Increase in the Commercial Register of the Canton of Vaud, but in no event later than 10:00 a.m. New York City time on the last business day immediately preceding the Closing Date, the Company will:

(i)deliver to the Representatives and the share registrar of the Company, (A) a copy of the certified excerpt of the journal entry (Tagesregister) or a copy of the certified excerpt from the Commercial Register of the Canton of Vaud evidencing the registration of the Capital Increase in the Commercial Register of the Canton of Vaud and the issuance of 14,300,000 Offered Shares, (B) a copy of the certified updated articles of association of the Company evidencing the issuance of 14,300,000 Offered Shares and the respective changes to the Company’s articles of association, (C) copy of an assignment declaration evidencing the assignment of 14,300,000 Offered Shares from AC Immune USA, Inc. to the Company (D) a copy of the excerpt of the Company’s duly signed book of uncertificated securities (Wertrechtebuch) evidencing the entry of the Offered Shares and the holder of the Offered Shares, and (E) a copy of the excerpts of the Company’s share register (Aktienbuch) (in the form of screenshots or account statements from Computershare Trust Company, N.A.) evidencing the Offered Shares; and

(ii)take all (other) steps necessary to ensure that the Offered Shares will be (A) duly transferred to the Underwriters, and (B) freely transferable (subject to any applicable restrictions set forth in the articles of association of the Company) on the Closing Date.

Section 4.RESERVED.

Section 5.Additional Covenants.

Covenants of the Company. The Company further covenants and agrees with each Underwriter as follows:

(a)Delivery of Registration Statement, Time of Sale Prospectus and Prospectus. The Company shall furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period when a prospectus relating to the Offered Shares is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with sales of the Offered Shares, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

(b)Representatives’ Review of Proposed Amendments and Supplements. During the period when a prospectus relating to the Offered Shares is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule), the Company (i) will furnish to the Representatives for review, a reasonable period of time prior to the

14 

proposed time of filing of any proposed amendment or supplement to the Registration Statement, a copy of each such amendment or supplement and (ii) will not amend or supplement the Registration Statement (including any amendment or supplement through incorporation of any report filed under the Exchange Act) without the Representatives’ prior written consent, which consent shall not be unreasonably withheld. Prior to amending or supplementing any preliminary prospectus, the Time of Sale Prospectus or the Prospectus (including any amendment or supplement through incorporation of any report filed under the Exchange Act), the Company shall furnish to the Representatives for review, a reasonable amount of time prior to the time of filing or use of the proposed amendment or supplement, a copy of each such proposed amendment or supplement. The Company shall not file or use any such proposed amendment or supplement without the Representatives’ prior written consent, which consent shall not be unreasonably withheld. The Company shall file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c)Free Writing Prospectuses. The Company shall furnish to the Representatives for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of each proposed free writing prospectus or any amendment or supplement thereto prepared by or on behalf of, used by, or referred to by the Company, and the Company shall not file, use or refer to any proposed free writing prospectus or any amendment or supplement thereto without the Representatives’ prior written consent, which consent shall not be unreasonably withheld. The Company shall furnish to each Underwriter, without charge, as many copies of any free writing prospectus prepared by or on behalf of, used by or referred to by the Company as such Underwriter may reasonably request. If at any time when a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with sales of the Offered Shares (but in any event if at any time through and including the Closing Date) there occurred or occurs an event or development as a result of which any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company conflicted or would conflict with the information contained in the Registration Statement 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 prevailing at such time, not misleading, the Company shall promptly amend or supplement such free writing prospectus to eliminate or correct such conflict so that the statements in such free writing prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at such time, not misleading, as the case may be; provided, however, that prior to amending or supplementing any such free writing prospectus, the Company shall furnish to the Representatives for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of such proposed amended or supplemented free writing prospectus, and the Company shall not file, use or refer to any such amended or supplemented free writing prospectus without the Representatives’ prior written consent, which consent shall not be unreasonably withheld.

(d)Filing of Underwriter Free Writing Prospectuses. The Company shall not take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of such Underwriter that such Underwriter otherwise would not have been required to file thereunder.

(e)Amendments and Supplements to Time of Sale Prospectus. If the Time of Sale Prospectus is being used to solicit offers to buy the Offered Shares at a time when the Prospectus is not yet available to prospective purchasers, and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus so that the Time of Sale Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus

15 

conflicts with the information contained in the Registration Statement, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, the Company shall (subject to Section 5(b) and Section 5(c) hereof) promptly prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the information contained in the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f)Certain Notifications and Required Actions. After the date of this Agreement, the Company shall promptly advise the Representatives in writing of: (i) the receipt of any comments of, or requests for additional or supplemental information from, the Commission; (ii) the time and date of any filing of any post-effective amendment to the Registration Statement or any amendment or supplement to any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus; (iii) the time and date that any post-effective amendment to the Registration Statement becomes effective; and (iv) the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or any amendment or supplement to any preliminary prospectus, the Time of Sale Prospectus or the Prospectus or of any order preventing or suspending the use of any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus, or of any proceedings to remove, suspend or terminate from listing or quotation the Shares from any securities exchange upon which they are listed for trading or included or designated for quotation, or of the threatening or initiation of any proceedings for any of such purposes. If the Commission shall enter any such stop order at any time, the Company will use its best efforts to obtain the lifting of such order at the earliest possible moment. Additionally, the Company agrees that it shall comply with all applicable provisions of Rule 424(b), Rule 433 and Rule 430A under the Securities Act and will use its reasonable efforts to confirm that any filings made by the Company under Rule 424(b) or Rule 433 were received in a timely manner by the Commission.

(g)Amendments and Supplements to the Prospectus and Other Securities Act Matters. If any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus so that the Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) to a purchaser, not misleading, or if in the opinion of the Representatives or counsel for the Underwriters it is otherwise necessary to amend or supplement the Prospectus to comply with applicable law, the Company agrees (subject to Section 5(b) and Section 5(c))) hereof to promptly prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) to a purchaser, not misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law. Neither the Representatives’ consent to, nor delivery of, any such amendment or supplement shall constitute a waiver of any of the Company’s obligations under Section 5(b) and Section 5(c).

(h)Blue Sky Compliance. The Company shall cooperate with the Representatives and counsel for the Underwriters to qualify or register the Offered Shares for sale under (or obtain exemptions

16 

from the application of) the state securities or blue sky laws or Canadian provincial securities laws (or other foreign laws as the Representatives shall reasonably request) of those jurisdictions reasonably designated by the Representatives, shall comply with such laws and shall continue such qualifications, registrations and exemptions in effect so long as required for the distribution of the Offered Shares. The Company shall not be required to qualify as a foreign corporation or to take any action that would subject it to general service of process in any such jurisdiction where it is not presently qualified or where it would be subject to taxation as a foreign corporation. The Company will advise the Representatives promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Offered Shares for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company shall use its best efforts to obtain the withdrawal thereof at the earliest possible moment.

(i)Use of Proceeds. The Company shall apply the net proceeds from the sale of the Offered Shares sold by it in the manner described under the caption “Use of Proceeds” in the Registration Statement, the Time of Sale Prospectus and the Prospectus.

(j)Transfer Agent. The Company shall engage and maintain, at its expense, a registrar and transfer agent for the Shares.

(k)Earnings Statement. The Company will make generally available (which may be satisfied by filing with the Commission’s EDGAR system) to its security holders and to the Representatives as soon as practicable an earnings statement (which need not be audited) covering a period of at least twelve months beginning with the first fiscal quarter of the Company commencing after the date of this Agreement that will satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

(l)Continued Compliance with Securities Laws. The Company will comply with the Securities Act and the Exchange Act so as to permit the completion of the distribution of the Offered Shares as contemplated by this Agreement, the Registration Statement, the Time of Sale Prospectus and the Prospectus. Without limiting the generality of the foregoing, the Company will, during the period when a prospectus relating to the Offered Shares is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule), file on a timely basis with the Commission and Nasdaq all reports and documents required to be filed under the Exchange Act.

(m)Listing. The Company will use its best efforts to list, subject to notice of issuance, the Offered Shares on Nasdaq.

(n)Company to Provide Copy of the Prospectus in Form That May be Downloaded from the Internet. If requested by the Representatives, the Company shall cause to be prepared and delivered, at its expense, within one business day from the effective date of this Agreement, to the Representatives an “electronic Prospectus” to be used by the Underwriters in connection with the offering and sale of the Offered Shares. As used herein, the term “electronic Prospectus” means a form of Time of Sale Prospectus, and any amendment or supplement thereto, that meets each of the following conditions: (i) it shall be encoded in an electronic format, satisfactory to the Representatives, that may be transmitted electronically by the Representatives and the other Underwriters to offerees and purchasers of the Offered Shares; (ii) it shall disclose the same information as the paper Time of Sale Prospectus, except to the extent that graphic and image material cannot be disseminated electronically, in which case such graphic and image material shall be replaced in the electronic Prospectus with a fair and accurate narrative description or tabular representation of such material, as appropriate; and (iii) it shall be in or convertible into a paper

17 

format or an electronic format, satisfactory to the Representatives, that will allow investors to store and have continuously ready access to the Time of Sale Prospectus at any future time, without charge to investors (other than any fee charged for subscription to the Internet as a whole and for on-line time). The Company hereby confirms that it has included or will include in the Prospectus filed pursuant to EDGAR or otherwise with the Commission and in the Registration Statement at the time it was declared effective an undertaking that, upon receipt of a request by an investor or his or her representative, the Company shall transmit or cause to be transmitted promptly, without charge, a paper copy of the Time of Sale Prospectus.

(o)Reserved

(p)Restriction on Sale of Securities. For the period specified below (the “Lock-Up Period”), the Company will not, directly or indirectly, take any of the following actions with respect to its Shares or any shares convertible into or exchangeable or exercisable for any of its Shares (“Lock-Up Shares”): (i) offer, sell, issue, contract to sell, pledge or otherwise dispose of Lock-Up Shares, (ii) offer, sell, issue, contract to sell, contract to purchase or grant any option, right or warrant to purchase Lock-Up Shares, (iii) enter into any swap, hedge or any other agreement that transfers, in whole or in part, the economic consequences of ownership of Lock-Up Shares, (iv) establish or increase a put equivalent position or liquidate or decrease a call equivalent position in Lock-Up Shares within the meaning of Section 16 of the Exchange Act or (v) file with the Commission a registration statement under the Securities Act relating to Lock-Up Shares, or publicly disclose the intention to take any such action, without the prior written consent of the Representatives. The Lock-Up Period will commence on the date hereof and continue through and including the 60th day following the date of the Prospectus or such earlier date that the Representatives consent to in writing.

The restrictions contained in the preceding paragraph shall not apply to (a) the Shares to be issued or sold hereunder; (b) the issuance by the Company of Shares upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof or described in the Time of Sale Prospectus and the Prospectus; (c) the issuance by the Company of any options or warrants pursuant to any employee equity incentive plan or share ownership plan existing on the date hereof or described in the Time of Sale Prospectus and the Prospectus; (d) the filing by the Company of a registration statement with the Commission on Form S-8 in respect of any shares issued under or the grant of any award pursuant to an employee equity incentive plan or share ownership plan existing on the date hereof or described in the Time of Sale Prospectus and the Prospectus; (e) the transfer of Shares or any securities convertible into or exchangeable for Shares pursuant to a bona fide third-party tender offer, merger, consolidation or other similar transaction that is approved by the board of directors of the Company, made to all holders of Shares, involving a Change of Control (as defined below) after the completion of the offering of the Shares, provided that in the event that the tender offer, merger, consolidation or other such transaction is not completed, the Shares or any securities convertible into or exchangeable for Shares shall remain subject to the restrictions contained in the preceding paragraph; (f) the sale or issuance of or entry into an agreement to sell or issue Shares or securities convertible into or exercisable for Shares in connection with any (i) mergers, (ii) acquisition of securities, businesses, property, technologies or other assets, (iii) joint ventures, (iv) strategic alliances, commercial relationships or other collaborations, (v) the assumption of employee benefit plans in connection with mergers or acquisitions, or (vi) the filing of a Registration Statement with respect to any of the foregoing; provided that the aggregate number of Shares or securities convertible into or exercisable for Shares (on an as-converted or as-exercised basis, as the case may be) that the Company may sell or issue or agree to sell or issue pursuant to this subclause (f) shall not exceed 10% of the total number of Shares issued and outstanding immediately following the completion of the transactions contemplated by this Agreement (determined on a fully-diluted basis and as adjusted for share splits, share dividends and other similar events after the date hereof); and provided further that each recipient of Shares or securities convertible into or exercisable for Stock pursuant to this subclause (f)

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shall, on or prior to such issuance, execute a lock-up letter in substantially the form of Exhibit A hereto with respect to the remaining portion of the Lock-Up Period or (g) the sale and issuance by the Company of Shares in connection with sales under an “at-the-market” equity offering program pursuant to an Open Market Sale Agreement^SM (the “Sale Agreement”) between the Company and Jefferies LLC dated as of September 8, 2020, provided no sales shall be made under the Sale Agreement until the thirtieth day following the date of the Prospectus.

For purposes of the foregoing paragraph, “Change of Control” shall mean the transfer (whether by tender offer, merger, consolidation or other similar transaction), in one transaction or a series of related transactions, to a person or group of affiliated persons (other than an Underwriter pursuant to the public offering contemplated by this Agreement), of the Company’s voting securities if, after such transfer, such person or group of affiliated persons would hold more than 50% of the outstanding voting securities of the Company (or the surviving entity).

In addition, during the Lock-Up Period, the Company will enforce its shareholders’ obligations to comply with any and all restrictions on the sale, pledge or transfer of the Company’s Shares pursuant to any shareholders’ agreement by and among the Company and its shareholders.

(q)Future Reports to the Representatives. During the period of one (1) year hereafter, the Company will furnish to the Representatives, c/o Jefferies LLC, at 520 Madison Avenue, New York, New York 10022, Attention: Global Head of Syndicate, c/o Leerink Partners LLC, at 1301 Avenue of the Americas, 12^th Floor, New York, New York 10019, Attention: Stuart Nayman, Esq. and, upon request, to each of the other Underwriters, as soon as practicable after the end of each fiscal year, a copy of its annual report to shareholders for such year; and the Company will furnish to the Representatives (i) as soon as available, a copy of each report and any definitive proxy statement of the Company filed with the Commission under the Exchange Act or mailed to shareholders, and (ii) from time to time, such other information concerning the Company as the Representatives may reasonably request. However, so long as the Company is subject to the reporting requirements of either Section 13 or Section 15(d) of the Exchange Act and is timely filing reports with the Commission on EDGAR, it is not required to furnish such reports or statements to the Underwriters.

(r)Investment Limitation. The Company shall not invest or otherwise use the proceeds received by the Company from its sale of the Offered Shares in such a manner as would require the Company to register as an investment company under the Investment Company Act.

(s)Absence of Manipulation. The Company will not take, directly or indirectly, any action designed to or that would constitute or that might reasonably be expected to cause or result in, stabilization or manipulation of the price of any securities of the Company to facilitate the sale or resale of the Offered Shares; provided that no representation is made in this Section with respect to the Underwriters.

Section 6.Payment of Expenses. The Company will pay all expenses incident to the performance of its obligations under this Agreement, including but not limited to any filing fees and other expenses (including fees and disbursements of counsel to the Underwriters) incurred in connection with qualification of the Offered Shares for sale under the laws of such jurisdictions as the Representatives designate and the preparation and printing of memoranda relating thereto in an amount not to exceed $10,000, costs and expenses related to the review by FINRA of the Offered Shares (including filing fees and the fees and expenses of counsel for the Underwriters relating to such review in an amount not to exceed $30,000), costs and expenses relating to investor presentations or any Road Show in connection with the offering and sale of the Offered Shares including, without limitation, any travel expenses of the Company’s officers and employees and any other expenses of the Company including fees and expenses incident to listing the Offered Shares on the New York Stock Exchange, American Stock Exchange,

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Nasdaq and other national and foreign exchanges, fees and expenses in connection with the registration of the Offered Shares under the Exchange Act, and expenses incurred in distributing the Registration Statement, the Time of Sale Prospectus, the Prospectus (including any amendments and supplements thereto) to the Underwriters and for expenses incurred for preparing, printing and distributing any free writing prospectuses to investors or prospective investors. Notwithstanding the foregoing, each of the several Underwriters will pay its own costs and expenses relating to any investor presentations or Road Show.

Section 7.Covenant of the Underwriters. Each Underwriter severally and not jointly covenants with the Company not to take any action that would result in the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not, but for such actions, be required to be filed by the Company under Rule 433(d).

Section 8.Conditions of the Obligations of the Underwriters. The respective obligations of the several Underwriters hereunder to subscribe, and to purchase and pay for, the Offered Shares as provided herein shall be subject to the accuracy of the representations and warranties on the part of the Company set forth in Section 1 hereof as of the date hereof and as of the Closing Date as though then made to the timely performance by the Company of its covenants and other obligations hereunder and the delivery by the Company of documents satisfactory to the Underwriters evidencing such timely performance, including without limitation the documents mentioned in this Agreement, and to each of the following additional conditions:

(a)Comfort Letter. On the date hereof, the Representatives shall have received from PricewaterhouseCoopers SA, the Company’s independent registered public accountants, a letter dated the date hereof addressed to the Underwriters, in form and substance satisfactory to the Representatives, containing statements and information of the type ordinarily included in accountant’s “comfort letters” to underwriters, delivered according to Statement of Auditing Standards No. 72 (or any successor bulletin), with respect to the audited and unaudited consolidated financial statements and certain financial information contained in the Registration Statement, the Time of Sale Prospectus, and each free writing prospectus, if any.

(b)Compliance with Registration Requirements; No Stop Order; No Objection from FINRA.

(i)The Company shall have filed the Prospectus with the Commission (including the information previously omitted from the Registration Statement pursuant to Rule 430B under the Securities Act) in the manner and within the time period required by Rule 424(b) under the Securities Act; or the Company shall have filed a post-effective amendment to the Registration Statement containing the information previously omitted from the Registration Statement pursuant to such Rule 430B, and such post-effective amendment shall have become effective.

(ii)No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment to the Registration Statement shall be in effect, and no proceedings for such purpose shall have been instituted or threatened by the Commission.

(iii)If a filing has been made with FINRA, FINRA shall have raised no objection to the fairness and reasonableness of the underwriting terms and arrangements.

(c)No Material Adverse Change. Subsequent to the execution and delivery of this Agreement and through and including the Closing Date, there shall not have occurred (i) any change in the

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condition (financial or otherwise), results of operations, business or properties or prospects of the Company which, in the judgment of the Representatives, is material and adverse and makes it impractical or inadvisable to market the Offered Shares; (ii) any change in U.S. or international financial, political or economic conditions or currency exchange rates or exchange controls the effect of which is such as to make it, in the judgment of the Representatives, impractical to market or to enforce contracts for the sale of the Offered Shares, whether in the primary market or in respect of dealings in the secondary market; (iii) any suspension or material limitation of trading in securities generally on the New York Stock Exchange or Nasdaq, or any setting of minimum or maximum prices for trading on such exchange; (iv) any banking moratorium declared by any U.S. federal, New York or Swiss authorities; (v) any suspension of trading of any securities of the Company on any exchange or in the over-the-counter market; (vi) any major disruption of settlements of securities, payment, or clearance services in the United States or any other country where such securities are listed or (vii) any attack on, outbreak or escalation of hostilities or act of terrorism involving the United States, any declaration of war by Congress or any other national or international calamity or emergency if, in the judgment of the Representatives, the effect of any such attack, outbreak, escalation, act, declaration, calamity or emergency is such as to make it impractical or inadvisable to market the Offered Shares or to enforce contracts for the sale of the Offered Shares.

(d)Opinion of U.S. Counsel for the Company. On the Closing Date, the Representatives shall have received the opinion of Davis Polk & Wardwell LLP, U.S. counsel for the Company, dated as of such date, in form and substance satisfactory to the Representatives.

(e)Opinion of Swiss Counsel for the Company. On the Closing Date, the Representatives shall have received the opinion of Bär & Karrer AG, Swiss counsel for the Company, dated as of such date, in form and substance satisfactory to the Representatives.

(f)Opinions of Intellectual Property Counsel for the Company. On the Closing Date, the Representatives shall have the received opinion of each of (i) Boult Wade Tennant LLP, (ii) Ice Miller LLP, (iii) McNeill Baur PLLC and (iv) Vossius & Partner Patentanwaelte Rechtsanwaelte mbB, each intellectual property counsel for the Company, in form and substance satisfactory to the Representatives.

(g)Opinion of U.S. Counsel for the Underwriters. On the Closing Date, the Representatives shall have received such opinion or opinions of Paul Hastings LLP, U.S. counsel for the Underwriters, with respect to such matters as the Representatives may require, in form and substance satisfactory to the Underwriters and dated as of such date, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(h)Opinion of Swiss Counsel for the Underwriters. On the Closing Date, the Representatives shall have received such opinion or opinions of Homburger AG, Swiss counsel for the Underwriters, with respect to such matters as the Representatives may require, in form and substance satisfactory to the Underwriters and dated as of such date, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(i)Officers’ Certificate. The Representatives shall have received a certificate, dated the Closing Date, of an executive officer of the Company and a principal financial or accounting officer of the Company in which such officers shall state that: the representations and warranties of the Company in this Agreement are true and correct; the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date; no stop order suspending the effectiveness of any Registration Statement has been issued and no proceedings for that purpose have been instituted or, to the best of their knowledge and after reasonable investigation, are contemplated by the Commission; the Rule 462(b) Registration Statement (if any) satisfying the requirements of

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subparagraphs (1) and (3) of Rule 462(b) was timely filed pursuant to Rule 462(b), including payment of the applicable filing fee in accordance with Rule 111(a) or (b) of Regulation S-T of the Commission; and, subsequent to the date of the most recent financial statements in the Registration Statement, the Time of Sale Prospectus and the Prospectus, there has been no material adverse change in the condition (financial or otherwise), results of operations, business, properties or prospects of the Company except as set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus or as described in such certificate.

(j)[Reserved].

(k)Bring-down Comfort Letter. On the Closing Date, the Representatives shall have received PricewaterhouseCoopers SA, the Company’s current independent registered public accountants, letters dated such date, in form and substance satisfactory to the Representatives, which letter shall: (i) reaffirm the statements made in the letter furnished by each such firm pursuant to Section 8(a), except that the specified date referred to therein for the carrying out of procedures shall be no more than three business days prior to the Closing Date; and (ii) cover certain financial information contained in the Prospectus.

(l)Lock-Up Agreements. On or prior to the date hereof, the Company shall have furnished to the Representatives an agreement in the form of Exhibit A hereto from each of the persons listed on Exhibit B hereto, and each such agreement shall be in full force and effect on the Closing Date.

(m)Rule 462(b) Registration Statement. In the event that a Rule 462(b) Registration Statement is filed in connection with the offering contemplated by this Agreement, such Rule 462(b) Registration Statement shall have been filed with the Commission on the date of this Agreement and shall have become effective automatically upon such filing.

(n)Additional Documents. On or before the Closing Date, the Representatives and counsel for the Underwriters shall have received such information, documents and opinions as they may reasonably request for the purposes of enabling them to pass upon the issuance and sale of the Offered Shares as contemplated herein, or in order to evidence the accuracy of any of the representations and warranties, or the satisfaction, compliance with or performance of any of the conditions, agreements or covenants, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Offered Shares as contemplated herein and in connection with the other transactions contemplated by this Agreement shall be satisfactory in form and substance to the Representatives and counsel for the Underwriters.

(o)Registration in Commercial Register. On the Closing Date, the Capital Increase shall have been registered in the Commercial Register of the Canton of Vaud.

If any condition specified in this Section 8 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Representatives by notice from the Representatives to the Company at any time on or prior to the Closing Date, which termination shall be without liability on the part of any party to any other party, except that Section 6, Section 9, Section 11 and Section 12 (and other Sections of this Agreement as referenced in the aforementioned Sections) shall at all times be effective and shall survive such termination. The Company shall inform the Representatives immediately upon becoming aware of any fact or matter that constitutes or could reasonably be expected to constitute or result in a non-satisfaction of any of the conditions specified in this Section 8.

Section 9.Reimbursement of Underwriters’ Expenses. If this Agreement is terminated by the Representatives pursuant to Section 8, Section 11(d) or Section 14, or if the sale to the Underwriters of the Offered Shares on the Closing Date is not consummated because of any refusal,

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inability or failure on the part of the Company to perform any agreement herein or to comply with any provision hereof, the Company agrees to reimburse the Representatives and the other Underwriters (or such Underwriters as have terminated this Agreement with respect to themselves), severally, upon demand for all reasonable and documented out-of-pocket expenses that shall have been actually and reasonably incurred by the Representatives and the Underwriters in connection with the proposed purchase and the offering and sale of the Offered Shares, including, but not limited to, reasonable fees and disbursements of counsel, printing expenses, reasonable travel expenses, postage, facsimile and telephone charges.

Section 10.Effectiveness of this Agreement. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

Section 11.Indemnification.

(a)Indemnification of the Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its affiliates, directors, officers, employees and agents, and each person, if any, who controls any Underwriter within the meaning of the Securities Act or the Exchange Act against any loss, claim, damage, liability or expense, as incurred, to which such Underwriter or such affiliate, director, officer, employee, agent or controlling person may become subject, under the Securities Act, the Exchange Act, other federal or state statutory law or regulation, or the laws or regulations of Switzerland or of foreign jurisdictions where Offered Shares have been offered or sold or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of the Company), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, or the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading; (ii) any untrue statement or alleged untrue statement of a material fact included in any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act or the Prospectus (or any amendment or supplement to the foregoing), or (iii) any act or failure to act or any alleged act or failure to act by any Underwriter in connection with, or relating in any manner to, the Offered Shares or the offering contemplated hereby, and which is included as part of or referred to in any loss, claim, damage, liability or action arising out of or based upon any matter covered by clause (i), (ii) or (iii) above; or the omission or alleged omission to state therein a material fact necessary in order to make the statements, in the light of the circumstances under which they were made, not misleading; and to reimburse each Underwriter and each such affiliate, director, officer, employee, agent and controlling person for any and all reasonable expenses (including the reasonable fees and disbursements of counsel) as such expenses are incurred by such Underwriter or such affiliate, director, officer, employee, agent or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action; provided, however, that the foregoing indemnity agreement shall not apply to any loss, claim, damage, liability or expense to the extent, but only to the extent, arising out of or based upon any untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company by the Representatives in writing expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any such free writing prospectus or the Prospectus (or any amendment or supplement thereto), it being understood and agreed that the only such information consists of the information described in Section 11(b) below. The indemnity agreement and the obligations and liabilities of the Company set forth in this Section 11(a) shall be in addition to any liabilities that the Company may otherwise have.

(b)Indemnification of the Company, its Directors and Officers. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, each of its directors, each of its

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officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of the Securities Act or the Exchange Act, against any loss, claim, damage, liability or expense, as incurred, to which the Company, or any such director, officer or controlling person may become subject, under the Securities Act, the Exchange Act, or other federal or state statutory law or regulation, or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of such Underwriter), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, or 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 or (ii) any untrue statement or alleged untrue statement of a material fact included in any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433 of the Securities Act or the Prospectus (or any such amendment or supplement) or the omission or alleged omission to state therein a material fact necessary in order to make the statements, in the light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, such preliminary prospectus, the Time of Sale Prospectus, such free writing prospectus or the Prospectus (or any such amendment or supplement), in reliance upon and in conformity with information relating to such Underwriter furnished to the Company by the Representatives in writing expressly for use therein; and to reimburse the Company, or any such director, officer or controlling person for any and all reasonable expenses (including the reasonable fees and disbursements of counsel) as such expenses are incurred by the Company, or any such director, officer or controlling person in connection with investigating, defending, settling, compromising or paying any such loss, claim, damage, liability, expense or action. The Company hereby acknowledges that the only information that the Representatives have furnished to the Company expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) of the Securities Act or the Prospectus (or any amendment or supplement to the foregoing) are the concession and reallowance figures appearing in the sixth paragraph under the caption “Underwriting” and the information relating to stabilizing transactions, syndicate covering transactions and penalty bids contained in the paragraphs under the caption “Underwriting—Stabilization” in the Final Prospectus Supplement. The indemnity agreement set forth in this Section 11(b) shall be in addition to any liabilities that each Underwriter may otherwise have.

(c)Notifications and Other Indemnification Procedures. Promptly after receipt by an indemnified party under this Section 11 of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against an indemnifying party under this Section 11, notify the indemnifying party in writing of the commencement thereof, but the omission so to notify the indemnifying party will not relieve the indemnifying party from any liability which it may have to any indemnified party to the extent the indemnifying party is not materially prejudiced as a proximate result of such failure and shall not in any event relieve the indemnifying party from any liability that it may have otherwise than on account of this indemnity agreement. In case any such action is brought against any indemnified party and such indemnified party seeks or intends to seek indemnity from an indemnifying party, the indemnifying party will be entitled to participate in, and, to the extent that it shall elect, jointly with all other indemnifying parties similarly notified, by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof with counsel reasonably satisfactory to such indemnified party; provided, however, that if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that a conflict may arise between the positions of the indemnifying party and the indemnified party in conducting the defense of any such action or that there may be legal defenses available to it and/or other indemnified parties which are different from or additional to those available to the indemnifying party, the indemnified party or parties shall have the right to select separate counsel to

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assume such legal defenses and to otherwise participate in the defense of such action on behalf of such indemnified party or parties. Upon receipt of notice from the indemnifying party to such indemnified party of such indemnifying party’s election so to assume the defense of such action and approval by the indemnified party of counsel, the indemnifying party will not be liable to such indemnified party under this Section 11 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless (i) the indemnified party shall have employed separate counsel in accordance with the proviso to the preceding sentence (it being understood, however, that the indemnifying party shall not be liable for the fees and expenses of more than one separate counsel (together with local counsel), representing the indemnified parties who are parties to such action), which counsel (together with any local counsel) for the indemnified parties shall be selected by the Representatives (in the case of counsel for the indemnified parties referred to in Section 11(a) above) or by the Company (in the case of counsel for the indemnified parties referred to in Section 11(b) above)) or (ii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the action or (iii) the indemnifying party has authorized in writing the employment of counsel for the indemnified party at the expense of the indemnifying party, in each of which cases the reasonable fees and expenses of counsel shall be at the expense of the indemnifying party and shall be paid as they are incurred.

(d)Settlements. The indemnifying party under this Section 11 shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party against any loss, claim, damage, liability or expense by reason of such settlement or judgment. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement, compromise or consent to the entry of judgment in any pending or threatened action, suit or proceeding in respect of which any indemnified party is or could have been a party and indemnity was or could have been sought hereunder by such indemnified party, unless such settlement, compromise or consent includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such action, suit or proceeding and does not include an admission of fault or culpability or a failure to act by or on behalf of such indemnified party.

Section 12.Contribution. If the indemnification provided for in Section 11 is for any reason held to be unavailable to or otherwise insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount paid or payable by such indemnified party, as incurred, as a result of any losses, claims, damages, liabilities or expenses referred to therein (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 Offered Shares pursuant to this Agreement or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and the Underwriters, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, liabilities 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 Offered Shares pursuant to this Agreement shall be deemed to be in the same respective proportions as the total proceeds from the offering of the Offered Shares pursuant to this Agreement (before deducting expenses) received by the Company, and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth on the front cover page of the Prospectus, bear to the aggregate public offering price of the Offered Shares as set forth on such cover. 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, on the one hand, or the Underwriters, on the

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other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in Section 11(c) any reasonable and properly documented legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any action or claim. The provisions set forth in Section 11(c) with respect to notice of commencement of any action shall apply if a claim for contribution is to be made under this Section 12; provided, however, that no additional notice shall be required with respect to any action for which notice has been given under Section 11(c) for purposes of indemnification.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 12 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 12.

Notwithstanding the provisions of this Section 12, no Underwriter shall be required to contribute any amount in excess of the underwriting discounts and commissions received by such Underwriter in connection with the Offered Shares underwritten by it and distributed to the public. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 12 are several, and not joint, in proportion to their respective underwriting commitments as set forth opposite their respective names on Schedule A. For purposes of this Section 12, each affiliate, director, officer, employee and agent of an Underwriter and each person, if any, who controls an Underwriter within the meaning of the Securities Act or the Exchange Act 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 the Securities Act and the Exchange Act shall have the same rights to contribution as the Company.

Section 13.Default of One or More of the Several Underwriters. If, on the Closing Date any one or more of the several Underwriters shall fail or refuse to purchase Offered Shares that it or they have agreed to purchase hereunder on such date, and the aggregate number of Offered Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase does not exceed 10% of the aggregate number of the Offered Shares to be purchased on such date, the Representatives may make arrangements satisfactory to the Company for the purchase of such Offered Shares by other persons, including any of the Underwriters, but if no such arrangements are made by such date, the other Underwriters shall be obligated, severally and not jointly, in the proportions that the number of Offered Shares set forth opposite their respective names on Schedule A bears to the aggregate number of Offered Shares set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as may be specified by the Representatives with the consent of the non-defaulting Underwriters, to purchase the Offered Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date. If, on the Closing Date any one or more of the Underwriters shall fail or refuse to purchase Offered Shares and the aggregate number of Offered Shares with respect to which such default occurs exceeds 10% of the aggregate number of Offered Shares to be purchased on such date, and arrangements satisfactory to the Representatives and the Company for the purchase of such Offered Shares are not made within 48 hours after such default, this Agreement shall terminate without liability of any party to any other party except that the provisions of Section 6, Section 9, Section 11 and Section 12 (and other Sections of this Agreement as referenced in the aforementioned Sections) shall at all times be effective and shall survive such termination. In any such case either the Representatives or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days in

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order that the required changes, if any, to the Registration Statement and the Prospectus or any other documents or arrangements may be effected.

As used in this Agreement, the term “Underwriter” shall be deemed to include any person substituted for a defaulting Underwriter under this Section 13. Any action taken under this Section 13 shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

Section 14.Termination of this Agreement. On or prior to the Closing Date, this Agreement may be terminated by the Representatives by notice given to the Company if at any time: (i) trading or quotation in any of the Company’s securities shall have been suspended or limited by the Commission or by Nasdaq, or trading in securities generally on either the Nasdaq or the NYSE shall have been suspended or limited, or minimum or maximum prices shall have been generally established on any of such stock exchanges; (ii) a general banking moratorium shall have been declared by any of federal, New York or Swiss authorities; (iii) there shall have occurred any outbreak or escalation of national or international hostilities or any crisis or calamity, or any change in the United States or international financial markets, or any substantial change or development involving a prospective substantial change in United States’ or international political, financial or economic conditions, as in the judgment of the Representatives is material and adverse and makes it impracticable to market the Offered Shares in the manner and on the terms described in the Time of Sale Prospectus or the Prospectus or to enforce contracts for the sale of securities; (iv) in the judgment of the Representatives, there shall have occurred any Material Adverse Change; or (v) the Company shall have sustained a loss by strike, fire, flood, earthquake, accident or other calamity of such character as in the judgment of Representatives may interfere materially with the conduct of the business and operations of the Company regardless of whether or not such loss shall have been insured. Any termination pursuant to this Section 14 shall be without liability on the part of (a) the Company to any Underwriter, except that the Company shall be obligated to reimburse the expenses of the Representatives and the Underwriters pursuant to Section 6 or Section 9 hereof or (b) any Underwriter to the Company; provided, however, that the provisions of Section 11 and Section 12 (and other Sections of this Agreement as referenced in the aforementioned Sections) shall at all times be effective and shall survive such termination.

Section 15.No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) the purchase and sale of the Offered Shares pursuant to this Agreement, including the determination of the public offering price of the Offered Shares 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 contemplated hereby and the process leading to such transaction, each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company, or its stockholders, 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 contemplated hereby 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 contemplated hereby 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 contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

Section 16.Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Company, of its officers and of the several Underwriters set forth in or made pursuant to this Agreement will remain in full force

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and effect, regardless of any investigation made by or on behalf of any Underwriter or the Company or any of its or their partners, officers or directors or any controlling person, as the case may be, and, anything herein to the contrary notwithstanding, will survive delivery of and payment for the Offered Shares sold hereunder and any termination of this Agreement.

Section 17.Notices. All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:  

If to the Representatives:
	Jefferies LLC
	520 Madison Avenue
	New York, New York 10022, USA
	Facsimile:  (646) 619-4437
	Attention:  General Counsel
	Leerink Partners LLC
	1301 Avenue of the Americas, 12th Floor
	New York, New York 10019
	Facsimile: (646) 499-7051
	Attention: Stuart R. Nayman, Esq.

with copies to:	Paul Hastings LLP
	MetLife Building
	200 Park Avenue
	New York, New York 10166, USA
	Facsimile:  (212) 319-4090
	Attention:  Siavosh Salimi and William Magioncalda
	Homburger AG
	Prime Tower
	Hardstrasse 201
	8005 Zurich, Switzerland
	Facsimile:  +41 (0)43 222 15 00
	Attention: Dr. iur. Benjamin Leisinger

If to the Company:	AC Immune SA
	EPFL Innovation Park Building B
	1050 Lausanne, Switzerland
	Facsimile:  +41 21 345 91 20
	Attention: Chief Financial Officer
with copies to:	Bär & Karrer AG
	Brandschenkestrasse 90
	8002 Zurich, Switzerland
	Facsimile:  +41 58 261 50 01
	Attention: Prof. Dr. iur. Rolf Watter

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Davis Polk & Wardwell LLP
450 Lexington Avenue
New York, NY 10017, USA 

Email: derek.dostal@davispolk.com
Facsimile: (212) 701-5322
Attention: Derek Dostal

Any party hereto may change the address for receipt of communications by giving written notice to the others.

Section 18.Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto, including any substitute Underwriters pursuant to Section 13 hereof, and to the benefit of the affiliates, directors, officers, employees, agents and controlling persons referred to in Section 11 and Section 12 , and in each case their respective successors, and no other person will have any right or obligation hereunder. The term “successors” shall not include any purchaser of the Offered Shares as such from any of the Underwriters merely by reason of such purchase.

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

Section 20.Governing Law Provisions and Jurisdiction. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York applicable to agreements made and to be performed in such state, except that Swiss law shall govern matters of corporate law to the extent Swiss law mandatorily applies to such matters. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“Related Proceedings”) may be instituted in the federal courts of the United States of America located in the Borough of Manhattan in the City of New York or the courts of the State of New York in each case located in the Borough of Manhattan in the City of New York or, if so chosen by the Representatives, acting on behalf of the several Underwriters, in the courts at the place of the registered office of the Company (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 (a “Related Judgment”), as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum. Each party not located in the United States has irrevocably appointed Cogency Global Inc., which currently maintains a New York City office at 10 E 40^th Street, 10^th Floor, New York, NY 10016, United States of America, as its agent to receive service of process or other legal summons for purposes of any such suit, action or proceeding that may be instituted in any state or federal court in the Borough of Manhattan in the City of New York.

With respect to any Related Proceeding, each party irrevocably waives, to the fullest extent permitted by applicable law, all immunity (whether on the basis of sovereignty or otherwise) from jurisdiction, service of process, attachment (both before and after judgment) and execution to which it might otherwise be entitled in the Specified Courts, and with respect to any Related Judgment, each party waives any such immunity in the Specified Courts or any other court of competent jurisdiction, and will

29 

not raise or claim or cause to be pleaded any such immunity at or in respect of any such Related Proceeding or Related Judgment, including, without limitation, any immunity pursuant to the United States Foreign Sovereign Immunities Act of 1976, as amended.

Section 21.Judgment Currency. The obligations of the Company pursuant to this Agreement in respect of any sum due to any Underwriter shall, notwithstanding any judgment in a currency other than United States dollars, not be discharged until the first business day, following receipt by such Underwriter of any sum adjudged to be so due in such other currency, on which (and only to the extent that) such Underwriter may in accordance with normal banking procedures purchase United States dollars with such other currency; if the United States dollars so purchased are less than the sum originally due to such Underwriter hereunder, the Company agrees, as a separate obligation and notwithstanding any such judgment, to indemnify such Underwriter against such loss.

Section 22.General Provisions. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. Counterparts may be delivered via facsimile, electronic mail (including any electronic signature covered by the U.S. federal ESIGN Act of 2000, Uniform Electronic Transactions Act, the Electronic Signatures and Records Act or other applicable law, e.g., www.docusign.com) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

Each of the parties hereto acknowledges that it is a sophisticated business person who was adequately represented by counsel during negotiations regarding the provisions hereof, including, without limitation, the indemnification provisions of Section 11 and the contribution provisions of Section 12, and is fully informed regarding said provisions. Each of the parties hereto further acknowledges that the provisions of Section 11 and Section 12 hereof fairly allocate the risks in light of the ability of the parties to investigate the Company, its affairs and its business in order to assure that adequate disclosure has been made in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, each free writing prospectus and the Prospectus (and any amendments and supplements to the foregoing), as contemplated by the Securities Act and the Exchange Act.

30 

If the foregoing is in accordance with your understanding of our agreement, kindly sign and return to the Company the enclosed copies hereof, whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.

Very truly yours,
AC IMMUNE SA
By:	/s/ Andrea Pfeifer
	Name:	Andrea Pfeifer
	Title:	Chief Executive Officer
By:	/s/ Christopher Roberts
	Name:	Christopher Roberts
	Title:	Vice President, Finance and Interim Chief Financial Officer

The foregoing Underwriting Agreement is hereby confirmed and accepted by the Representatives in New York, New York as of the date first above written.

JEFFERIES LLC 

LEERINK PARTNERS LLC 

Acting individually and as Representatives 

of the several Underwriters named in 

the attached Schedule A.

JEFFERIES LLC
By:	/s/ Charlie Glazer
	Name:	Charlie Glazer
	Title:	Managing Director

LEERINK PARTNERS LLC
By:	/s/ Gabriel P. Cavazos
	Name:	Gabriel P. Cavazos
	Title:	Senior Managing Director

Schedule A

Underwriters	Number of Offered Shares to be Purchased
Jefferies LLC		7,150,000
Leerink Partners LLC		6,435,000
H.C. Wainwright & Co., LLC		715,000
Total		14,300,000

Schedule B-1

Free Writing Prospectuses Included in the Time of Sale Prospectus

None.

Schedule B-2

Pricing Information

1. Public offering price per share: $3.50 per share

2. Number of Offered Shares: 14,300,000 shares

3. Underwriting discount: 6.0%

Exhibit A

Form of Lock-up Agreement

December , 2023

Jefferies LLC 

Leerink Partners LLC

c/o Jefferies LLC 

520 Madison Avenue 

New York, New York 10022

c/o Leerink Partners LLC 

1301 Avenue of the Americas, 12^th Floor 

New York, New York 10019

As Representatives of the Several Underwriters

RE: AC Immune SA (the “Company”)

Ladies & Gentlemen:

The undersigned is an owner of common shares, par value CHF 0.02 per share, of the Company (“Shares”) or of securities convertible into or exchangeable or exercisable for Shares. The Company proposes to conduct a public offering of Shares (the “Offering”) for which Jefferies LLC and Leerink Partners LLC will act as the representatives of the underwriters (the “Representatives”). The undersigned recognizes that the Offering will benefit each of the Company and the undersigned. The undersigned acknowledges that the underwriters are relying on the representations and agreements of the undersigned contained in this letter agreement (the “Lockup Agreement”) in conducting the Offering and, at a subsequent date, in entering into an underwriting agreement (the “Underwriting Agreement”) and other underwriting arrangements with the Company with respect to the Offering.

Annex A sets forth definitions for capitalized terms used in this Lockup Agreement that are not defined in the body of this Lockup Agreement. Those definitions are a part of this Lockup Agreement.

In consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees that, during the Lock-up Period, the undersigned will not (and will cause any Family Member not to), without the prior written consent of the Representatives, which may withhold its consent in its sole discretion:

· Sell or Offer to Sell any Shares or Related Securities currently or hereafter owned either of record or beneficially (as defined in Rule 13d-3 under the Exchange Act) by the undersigned or such Family Member,

· enter into any Swap,

· make any demand for, or exercise any right with respect to, the registration under the Securities Act of the offer and sale of any Shares or Related Securities, or cause to be filed a

registration statement, prospectus or prospectus supplement (or an amendment or supplement thereto) with respect to any such registration, or

· publicly announce any intention to do any of the foregoing.

The foregoing will not apply to:

(i) (a) the exercise of stock options or other similar awards granted pursuant to the Company’s equity incentive plans or the vesting or settlement of awards granted pursuant to the Company’s equity incentive plans (including the delivery and receipt of Shares or Related Securities in connection with such vesting or settlement); provided that, in the case of this clause (a), the foregoing restrictions shall apply to any of the undersigned’s Shares issued upon such exercise, vesting or settlement; or (b) the transfer of Shares or any Related Securities from the undersigned to the Company (or the purchase and cancellation of same by the Company) upon a vesting event of the Company’s securities or upon the exercise of options to purchase Shares by the undersigned, in each case on a “cashless” or “net exercise” basis, or to cover income or withholding and other tax obligations of the undersigned in connection with such vesting or exercise of options for Shares of the Company, whether by means of a “net settlement” or otherwise;

(ii) transfers of Shares or Related Securities:

A. as a bona fide gift or gifts, including as a result of the operation of law or estate or intestate succession, or pursuant to a will or other testamentary document;

B. if the undersigned is a natural person, to a member of the immediate family member of the undersigned;

C. if the undersigned is a natural person, to any trust or other like entity for the direct or indirect benefit of the undersigned or the immediate family member of the undersigned;

D. if the undersigned is a natural person, by operation of law or by order of a court of competent jurisdiction pursuant to a qualified domestic order or in connection with a divorce settlement;

E. if the undersigned is a natural person, to a corporation, partnership, limited liability company or other entity of which the undersigned and the immediate family member of the undersigned are the direct or indirect legal and beneficial owners of all the outstanding equity securities or similar interests of such corporation, partnership, limited liability company or other entity;

F. the undersigned is a corporation, partnership, limited liability company or other entity, to any trust or other like entity for the direct or indirect benefit of the undersigned or any affiliate, wholly-owned subsidiary, limited partner, member or stockholder of the undersigned;

G. if the undersigned is a corporation, partnership, limited liability company or other entity, to any affiliate thereof;

H. if the undersigned is a corporation, partnership, limited liability company or other entity, to any investment fund or other entity controlled or managed by the undersigned; or

I. as a distribution to any affiliate, wholly-owned subsidiary, limited partner, member or stockholder of the undersigned;

provided that in the case of any transfer or distribution pursuant to clause (ii) above, (i) each donee, distributee or transferee executes and delivers to the Representatives an agreement in form and substance satisfactory to the Representatives stating that such transferee is receiving and holding such Shares and/or Related Securities subject to the provisions of this Lockup Agreement, (ii) agrees not to Sell or Offer to Sell such Shares and/or Related Securities, engage in any Swap or engage in any other activities restricted under this Lockup Agreement except in accordance with this Lockup Agreement (as if such transferee had been an original signatory hereto); provided further that in the case of any transfer or distribution pursuant to clause (ii) above, no filing under the Exchange Act shall be required except in the case of transfers pursuant to subclause (A);

(iii) the establishment or modification of any contract, instruction or trading plan intended to comply with Rule 10b5-1 under the Exchange Act for the transfer of Shares (a “10b5-1 Plan”); provided that (i) such plan does not provide for the transfer of Shares during the Lock-Up Period, (ii) the establishment of such plan shall not be voluntarily publicly announced or filed under the Exchange Act and (iii) to the extent a public announcement or filing under the Exchange Act, if any, is required by or on behalf of the undersigned or the Company regarding the establishment or modification of such plan, such announcement or filing shall include a statement to the effect that no transfer of Shares may be made under such plan during the Lock-Up Period;

(iv) the sale or transfer of Shares or Related Securities in transactions pursuant to a 10b5-1 Plan, entered into prior to the date hereof; provided, however, any required filings under the Exchange Act shall disclose by footnote that such transaction was pursuant to a 10b5-1 Plan;

(v) the transfer of Shares or Related Securities to the Company, pursuant to agreements or rights in existence on the date of the Underwriting Agreement under which the Company has the option to repurchase such shares or a right of first refusal with respect to transfers of such shares or in connection with the termination of the undersigned’s employment with the Company;

(vi) the transfer of Shares or Related Securities that occurs by any order or settlement resulting from any legal proceeding;

(vii) the transfer of Shares or Related Securities pursuant to a bona fide third-party tender offer, merger, consolidation or other similar transaction made to all holders of the Shares or Related Securities involving a change of control of the Company; provided that in the event that the tender offer, merger, amalgamation, consolidation or other such transaction is not completed, the Shares owned by the undersigned shall remain subject to the restrictions contained in this Lockup Agreement;

If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any Company-directed Shares the undersigned may purchase or otherwise receive in the Offering (including pursuant to a directed share program).

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 Shares or Related Securities held by the undersigned and the undersigned's Family Members, if any, except in compliance with the foregoing restrictions.

With respect to the Offering only, the undersigned waives any registration rights relating to registration under the Securities Act of the offer and sale of any Shares and/or any Related Securities owned either of record or beneficially by the undersigned, including any rights to receive notice of the Offering.

The undersigned confirms that the undersigned has not, and has no knowledge that any Family Member has, directly or indirectly, taken any action designed to or that might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale of the Shares. The undersigned will not, and will cause any Family Member not to take, directly or indirectly, any such action.

Whether or not the Offering occurs as currently contemplated or at all depends on market conditions and other factors. The Offering will only be made pursuant to the Underwriting Agreement, the terms of which are subject to negotiation between the Company and the underwriters.

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

The undersigned acknowledges and agrees that the underwriters have not provided any recommendation or investment advice nor have the underwriters solicited any action from the undersigned with respect to the Offering of the Shares and the undersigned has consulted their own legal, accounting, financial, regulatory and tax advisors to the extent deemed appropriate. The undersigned further acknowledges and agrees that, although the underwriters may provide certain Regulation Best Interest and Form CRS disclosures or other related documentation to you in connection with the Offering, the underwriters are not making a recommendation to you to participate in the Offering or sell any Shares at the price determined in the Offering, and nothing set forth in such disclosures or documentation is intended to suggest that any underwriter is making such a recommendation.

This Lockup Agreement may be delivered via facsimile, electronic mail (including pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g. www.docusign.com or www.echosign.com) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

This Lockup Agreement shall be governed by, and construed in accordance with, the laws of the State of New York.

Signature

Printed Name of Person Signing

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

Certain Defined Terms
Used in Lock-up Agreement

For purposes of the letter agreement to which this Annex A is attached and of which it is made a part:

· “Call Equivalent Position” shall have the meaning set forth in Rule 16a-1(b) under the Exchange Act.

· “Exchange Act” shall mean the Securities Exchange Act of 1934, as amended.

· “Family Member” shall mean the spouse of the undersigned, an immediate family member of the undersigned or an immediate family member of the undersigned's spouse, in each case living in the undersigned's household or whose principal residence is the undersigned's household (regardless of whether such spouse or family member may at the time be living elsewhere due to educational activities, health care treatment, military service, temporary internship or employment or otherwise). “Immediate family member” as used above shall have the meaning set forth in Rule 16a-1(e) under the Exchange Act.

· “Lock-up Period” shall mean the period beginning on the date hereof and continuing through the close of trading on the date that is 60 days after the date of the Prospectus (as defined in the Underwriting Agreement).

· “Put Equivalent Position” shall have the meaning set forth in Rule 16a-1(h) under the Exchange Act.

· “Related Securities” shall mean any options or warrants or other rights to acquire Shares or any securities exchangeable or exercisable for or convertible into Shares, or to acquire other securities or rights ultimately exchangeable or exercisable for or convertible into Shares.

· “Securities Act” shall mean the Securities Act of 1933, as amended.

· “Sell or Offer to Sell” shall mean to:

1. – sell, offer to sell, contract to sell or lend,

2. – effect any short sale or establish or increase a Put Equivalent Position or liquidate or decrease any Call Equivalent Position

3. – pledge, hypothecate or grant any security interest in, or

4. – in any other way transfer or dispose of,

in each case whether effected directly or indirectly. 

· “Swap” shall mean any swap, hedge or similar arrangement or agreement that transfers, in whole or in part, the economic risk of ownership of Shares or Related Securities, regardless of whether any such transaction is to be settled in securities, in cash or otherwise.

Capitalized terms not defined in this Annex A shall have the meanings given to them in the body of this lock-up agreement.

Exhibit B

Directors and Executive Officers
           Signing Lock-up Agreement           

Directors:

· Roy E. Twyman

· Douglas E. Williams, Ph.D.

· Werner Lanthaler, Ph.D.

· Carl June, M.D.

· Monika Bütler, Ph.D.

· Monica Shaw, M.D.

Executive Officers:

· Andrea Pfeifer, Ph.D.

· Marie Kosco-Vilbois, Ph.D.

· Christopher Roberts

· Jean-Fabien Monin

· Nuno Mendonca, M.D.