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06/08/2024 - ADC Therapeutics SA: Registration Statement Specified Transactions Form S 3

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Registration statement specified transactions form s 3

As filed with the Securities and Exchange Commission on August 6, 2024.

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

ADC THERAPEUTICS SA

(Exact name of Registrant as specified in its charter)

Switzerland Not Applicable
(State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.)

Biopôle

Route de la Corniche 3B

1066 Epalinges

Switzerland

+41 21 653 02 00

(Address, including zip code, and telephone number, including area code, of Registrant's principal executive offices)

ADC Therapeutics America, Inc.

430 Mountain Avenue, 4th Floor

Murray Hill, NJ 07974

(908) 546-5556

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Deanna L. Kirkpatrick
Yasin Keshvargar
Davis Polk & Wardwell LLP
450 Lexington Avenue
New York, NY 10017
(212) 450-4000
Dieter Gericke
Daniel Häusermann
Homburger AG
Hardstrasse 201
CH-8005 Zurich, Switzerland
+41 43 222 10 00

Approximate date of commencement of proposed sale to the public: From time to time after the effectiveness of this registration statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☐ Accelerated filer ☒
Non-accelerated filer ☐ Smaller reporting company ☒
Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

The registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act or until this registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

ADC Therapeutics SA (the "Company") is registering under this registration statement an aggregate of $300,000,000 of securities, including, in accordance with Rule 415(a)(6) under the Securities Act of 1933, as amended (the "Securities Act"), $194,281,632 of unsold securities previously registered under the Company's registration statement on Form S-3 (File No. 333-270570).

This registration statement contains two prospectuses:

· a base prospectus that covers the offering and sale of up to $300,000,000 of the Company's common shares, debt securities, warrants, subscription rights, purchase contracts and units; and
· a sales agreement prospectus supplement that covers the offering and sale of up to $100,000,000 of the Company's common shares that may be offered and sold under the Open Market Sale AgreementSM (the "sales agreement") between the Company and Jefferies LLC dated August 6, 2024.

The base prospectus immediately follows this explanatory note. The sales agreement prospectus supplement immediately follows the base prospectus. The common shares that may be offered and sold pursuant to the sales agreement prospectus supplement are included in the $300,000,000 of securities that may be offered and sold pursuant to the base prospectus. Any portion of the $100,000,000 included in the sales agreement prospectus supplement that remains unsold pursuant to the sales agreement will be available for sale in other offerings pursuant to the base prospectus and a corresponding prospectus supplement.

The information in this prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 6, 2024

PROSPECTUS

ADC THERAPEUTICS SA

$300,000,000

Common Shares
Debt Securities
Warrants
Subscription Rights
Purchase Contracts
Units

We may offer and sell from time to time, in one or more offerings, up to $300,000,000 of any combination of the following securities: common shares, debt securities, warrants, subscription rights, purchase contracts and units (collectively, the "securities"). The securities may be offered and sold in different series, at times, in amounts, at prices and on terms to be determined at or prior to the time of each offering. This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. We will provide the specific terms of these securities and the specific manner in which these securities will be offered and sold in supplements to this prospectus. The prospectus supplements may also supplement, update or amend information contained in this prospectus. You should read this prospectus and any applicable prospectus supplement before you invest.

The securities covered by this prospectus may be offered through one or more underwriters, dealers and agents, or directly to purchasers. The applicable prospectus supplement will set forth the names of the underwriters, dealers or agents, if any, any applicable commissions or discounts payable to them and the specific terms of the plan of distribution. For general information about the distribution of these securities, see "Plan of Distribution" beginning on page 39 of this prospectus.

Our common shares are listed on the New York Stock Exchange ("NYSE") under the symbol "ADCT."

Investing in our securities involves a high degree of risk. See the "Risk Factors" section beginning on page 4 of this prospectus and, if applicable, any risk factors described in any applicable prospectus supplement and in our Securities and Exchange Commission ("SEC") filings that are incorporated by reference in this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Prospectus dated , 2024.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS 1
OUR COMPANY 3
RISK FACTORS 4
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS 5
USE OF PROCEEDS 7
DIVIDEND POLICY 8
DESCRIPTION OF SHARE CAPITAL AND ARTICLES OF ASSOCIATION 9
DESCRIPTION OF DEBT SECURITIES 31
DESCRIPTION OF WARRANTS 33
DESCRIPTION OF SUBSCRIPTION RIGHTS 34
DESCRIPTION OF PURCHASE CONTRACTS 35
DESCRIPTION OF UNITS 36
FORMS OF SECURITIES 37
PLAN OF DISTRIBUTION 39
LEGAL MATTERS 41
EXPERTS 41
ENFORCEMENT OF JUDGMENTS 41
WHERE YOU CAN FIND MORE INFORMATION 42
INFORMATION INCORPORATED BY REFERENCE 43

ABOUT THIS PROSPECTUS

This prospectus is a part of a registration statement that we filed with the SEC using a "shelf" registration process. Under this shelf registration process, we may offer and sell, from time to time, in one or more offerings, up to $300,000,000 of any combination of the securities described in this prospectus. This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. Each time we offer or sell securities, we will provide the specific terms of these securities and the specific manner in which these securities will be offered and sold in supplements to this prospectus. The prospectus supplements may also supplement, update or amend information contained in this prospectus.

Before buying any of the securities that we are offering, you should carefully read both this prospectus and any prospectus supplement with all of the information incorporated by reference in this prospectus, as well as the additional information described under the heading "Where You Can Find More Information" and "Information Incorporated by Reference." These documents contain important information that you should consider when making your investment decision. We have filed or incorporated by reference exhibits to the registration statement of which this prospectus forms a part. You should read the exhibits carefully for provisions that may be important to you.

To the extent there is a conflict between the information contained in this prospectus, on the one hand, and the information contained in any prospectus supplement or in any document incorporated by reference in this prospectus, on the other hand, you should rely on the information in this prospectus, provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date-for example, a prospectus supplement or a document incorporated by reference in this prospectus-the statement in the document having the later date modifies or supersedes the earlier statement.

The information contained in this prospectus, any applicable prospectus supplement or any document incorporated by reference in this prospectus is accurate only as of their respective dates, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or the documents incorporated by reference in this prospectus or the sale of any securities. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

Neither we nor any underwriters, dealers or agents have authorized anyone to provide you with information that is different from that contained in this prospectus, any amendment or supplement to this prospectus, or any free writing prospectus we may authorize to be delivered or made available to you. Neither we nor any underwriters, dealers or agents take responsibility for, or provide assurance as to the reliability of, any other information that others may give you. This prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful.

For investors outside the United States: Neither we nor any underwriters, dealers or agents have taken any action that would permit the offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the securities described herein and the distribution of this prospectus outside the United States.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus to "ADC Therapeutics," "ADCT," the "Company," "we," "our," "ours," "us" or similar terms refer to ADC Therapeutics SA and its consolidated subsidiaries.

Trademarks

We own various trademark registrations and applications, and unregistered trademarks, including ADC Therapeutics, ADCT, ZYNLONTA and our corporate logo. All other trade names, trademarks and service

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marks of other companies appearing in this prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus may be referred to without the ® and ™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend to use or display other companies' trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

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OUR COMPANY

Overview

ADC Therapeutics is a leading, commercial-stage global pioneer in the field of antibody drug conjugates ("ADCs") with a validated and differentiated technology platform with multiple payloads and targets, a robust next-generation research and development toolbox, and specialized end-to-end capabilities. We are advancing our proprietary ADC technology to transform the treatment paradigm for patients with hematologic malignancies and solid tumors.

Company and Corporate Information

We are a Swiss stock corporation (société anonyme) organized under the laws of Switzerland. We were incorporated ‎as a Swiss limited liability company (société à responsabilité limitée) on June 6, 2011 and converted into a Swiss ‎stock corporation (société anonyme) under the laws of Switzerland on October 13, 2015. We have three ‎subsidiaries: ADC Therapeutics (UK) Limited, ADC Therapeutics America, Inc. and ADC Therapeutics (NL) BV. ‎Our principal executive office is located at Biopôle, Route de la Corniche 3B, 1066 Epalinges, Switzerland and our ‎telephone number is +41 21 653 02 00. Our website is adctherapeutics.com. The reference to our website is an inactive textual reference only, and information contained therein or connected thereto is not incorporated into this prospectus or the registration statement of which it forms a part.

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RISK FACTORS

Investing in our securities involves risk. Before making a decision to invest in our securities, you should carefully consider the risks described under "Risk Factors" in the applicable prospectus supplement and in our then-most recent Annual Report on Form 10-K, and any updates to those risk factors in our subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K incorporated by reference in this prospectus, together with all of the other information appearing or incorporated by reference in this prospectus and any applicable prospectus supplement, in light of your particular investment objectives and financial circumstances. These risks and uncertainties are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently believe to be immaterial may also adversely affect our business. If any of the events or developments were to occur, our business, results of operations, financial condition and prospects could suffer materially.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference in this prospectus contain statements that constitute ‎forward-looking statements within the meaning of Section 21E of the Exchange Act and Section 27A of the ‎Securities Act of 1933, as amended (the "Securities Act"). All statements other than statements of historical facts, ‎including statements regarding our future catalysts, results of operations and financial position, business and commercial ‎strategy, market opportunities, products and product candidates, research pipeline, ongoing and planned ‎preclinical studies and clinical trials, regulatory submissions and approvals, research and development costs, projected revenues and expenses and ‎the timing of revenues and expenses, timing and likelihood of success, as well as plans and objectives of ‎management for future operations are forward-looking statements. Many of the forward-looking statements ‎contained in this prospectus can be identified by the use of forward-looking words such as "anticipate," "believe," "could," "expect," "should," "plan," "intend," "estimate," "will" and "potential," among others.

Forward-looking statements are based on our management's beliefs and assumptions and on information available ‎to our management at the time such statements are made. Such statements are subject to known and unknown risks and uncertainties, and actual results may differ materially from those expressed or implied in the forward-looking statements due to various factors, including, but not limited to: the substantial net losses that we have incurred since our inception, our expectation to continue to incur losses for the foreseeable future and our need to raise additional capital to fund our operations and execute our business plan; our indebtedness under the loan agreement and guaranty (the "Loan Agreement") with certain affiliates and/or funds managed by each of Oaktree Capital Management, L.P. and Owl Rock Capital Advisors LLC, as lenders, and Blue Owl Opportunistic Master Fund I, L.P., as administrative agent, and the associated restrictive covenants thereunder; the purchase and sale agreement with certain entities managed by HealthCare Royalty Management, LLC and its negative effect on the amount of cash that we are able to generate from sales of, and licensing agreements involving, ZYNLONTA and on our attractiveness as an acquisition target; our ability to complete clinical trials on expected timelines, if at all; the timing, outcome and results of ongoing or planned clinical trials, whether the Company sponsored trials or through investigator initiated trials, and the sufficiency of such results; undesirable side effects or adverse events of our products and product candidates; our and our partners' ability to obtain and maintain regulatory approval for our product and product candidates; our and our partners' ability to successfully commercialize our products; the availability and scope of coverage and reimbursement for our products; the complexity and difficulty of manufacturing our products and product candidates; the substantial competition in our industry, including new technologies and therapies; the timing and results of any early research projects and future clinical outcomes; our reliance on third parties for preclinical studies and clinical trials and for the manufacture, production, storage and distribution of our products and product candidates and certain commercialization activities for our products; our ability to obtain, maintain and protect our intellectual property rights and our ability to operate our business without infringing on the intellectual property rights of others; our estimates regarding future revenue, expenses and needs for additional financing; the size and growth potential of the markets for our products and product candidates; potential product liability lawsuits and product recalls; and those identified in the "Risk Factors" section of this prospectus and the documents incorporated by reference in this prospectus.

Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements, whether as a result of any new information, future events, changed circumstances or otherwise. You should read this prospectus, the documents incorporated by reference in this prospectus and the documents that we have filed as exhibits to the registration statement of which this prospectus is a part completely and with the understanding that our actual future results may be materially different from what we expect.

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In addition, statements that "we believe" and similar statements reflect our beliefs and opinions on the relevant ‎subject. These statements are based upon information available to us as of the date of such statements, and while ‎we believe such information forms a reasonable basis for such statements, such information may be limited or ‎incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, ‎or review of, all potentially available relevant information. These statements are inherently uncertain and investors ‎are cautioned not to unduly rely upon these statements.‎

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USE OF PROCEEDS

Unless otherwise indicated in a prospectus supplement, the principal purpose of an offering would be to increase our capitalization and financial flexibility, and the net proceeds from our sale of the securities will be used for general corporate purposes and other business opportunities.

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DIVIDEND POLICY

We have never declared or paid cash dividends on our share capital. We intend to retain all available funds and any future earnings, if any, to fund the development and expansion of our business, and we do not anticipate paying any cash dividends in the foreseeable future. In addition, agreements governing our indebtedness, including the Loan Agreement, limit our ability to pay dividends. Any future determination related to dividend policy will be made at the discretion of our board of directors and will depend upon, among other factors, our results of operations, financial condition, capital requirements, contractual restrictions, business prospects and other factors our board of directors may deem relevant.

Under Swiss law, any dividend must be approved by our shareholders. In addition, our auditors must confirm that the dividend proposal of our board of directors to the shareholders conforms to Swiss statutory law and our articles of association. A Swiss corporation may pay dividends only if it has sufficient distributable profits from the previous or current business year (bénéfice résultant du bilan) or brought forward from previous business years (report des bénéfices) or if it has distributable reserves (réserves à libre disposition), each as evidenced by its audited stand-alone statutory balance sheet prepared pursuant to Swiss law and after allocations to reserves required by Swiss law and its articles of association have been deducted. Distributable reserves are generally booked either as free reserves (réserves libres) or as reserves from capital contributions (apports de capital). Distributions out of share capital, which is the aggregate par value of a corporation's issued shares, may be made only by way of a share capital reduction. See "Description of Share Capital and Articles of Association."

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DESCRIPTION OF SHARE CAPITAL AND ARTICLES OF ASSOCIATION

The Company

We are a Swiss stock corporation (société anonyme) organized under the laws of Switzerland. We were incorporated ‎as a Swiss limited liability company (société à responsabilité limitée) on June 6, 2011 with our registered office and ‎domicile in Epalinges, Canton of Vaud, Switzerland. We converted to a Swiss stock corporation under the laws of ‎Switzerland on October 13, 2015. Our domicile is in Epalinges, Canton of Vaud, Switzerland. Our registered office ‎and head office is currently located at Biopôle, Route de la Corniche 3B, 1066 Epalinges, Switzerland.‎

Articles of Association

Ordinary Capital Increase, Capital Range and Conditional Share Capital

Under Swiss law, we may increase our share capital (capital-actions) with a resolution of the general meeting of ‎shareholders (ordinary capital increase) that must be carried out by the board of directors within six months of ‎the respective general meeting in order to become effective. Under our articles of association and Swiss law, in the ‎case of subscription and increase against payment of contributions in cash, a resolution passed by a ‎majority of the shares represented at the general meeting of shareholders is required. In the case of subscription and ‎increase against contributions in kind or to fund acquisitions in kind, when shareholders' statutory pre-emptive ‎subscription rights or advance subscription rights are limited or withdrawn or where transformation of freely ‎disposable equity into share capital is involved, a resolution passed by two-thirds of the shares represented at a ‎general meeting of shareholders and the majority of the par value of the shares represented is required.‎

Under the Swiss Code of Obligations (Code des obligations) (the "CO"), our shareholders, by a ‎resolution passed by two-thirds of the shares represented at a general meeting of shareholders and the ‎majority of the par value of the shares represented, can:

· adopt conditional share capital (capital-actions conditionnel) in the aggregate amount of up to 50% of the share capital for the purpose of issuing shares in connection ‎with, among other things, option and conversion rights granted to shareholders, the creditors of bonds and similar debt instruments, employees, members ‎of the board of directors of the Company or of any group company, or to any third parties; and
· in the form of capital range (marge de fluctuation du capital), empower our board of directors to increase and/or decrease our share capital by up to 50% of the share capital, by issuing or canceling shares, or by increasing or decreasing the par value of shares, including through the creation of conditional share capital; such capital range is to be utilized by the board of directors within a period ‎determined by the shareholders but not exceeding five years from the date of the shareholder approval.‎

Pre-Emptive and Advance Subscription Rights

Pursuant to the CO, shareholders have pre-emptive subscription rights (droits de souscription préférentiels) to ‎subscribe for new issuances of shares. With respect to conditional capital, shareholders have (i) pre-emptive subscription rights for the subscription of option rights and (ii) advance subscription rights ‎‎(droit de souscription préalable) for the subscription of bonds and similar debt ‎instruments to which option or conversion rights are attached.‎

A resolution passed at a general meeting of shareholders by two-thirds of the shares represented and the ‎majority of the par value of the shares represented may authorize our board of directors to withdraw or limit pre-‎emptive subscription rights or advance subscription rights in certain circumstances.‎

If pre-emptive subscription rights are granted, but not exercised, the board of directors may allocate the unexercised ‎pre-emptive subscription rights at its discretion.‎

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Our Capital Range

Under our articles of association, we have a capital range ranging from CHF 7,123,355.68 (lower limit) to CHF 10,685,033.52 (upper limit). Our board of directors is authorized within the capital range to increase or decrease our share capital once or several times and in any amounts and to acquire or dispose of shares, directly or indirectly, until June 14, 2028, or until an earlier expiry of the capital range. The capital increase or reduction may be effected by issuing up to 44,520,973 common shares and canceling up to 44,520,973 common shares, as applicable, or by increasing or reducing the par value of the existing shares within the limits of the capital range, or by simultaneous reduction and re-increase of the share capital. If our share capital increases as a result of a share issue from conditional capital (see next subsection), the upper and lower limits of the capital range will increase in an amount corresponding to such increase.

In the event of a capital increase within the capital range, the board of directors has to determine the type of ‎contributions, the issue price and the date on which the dividend entitlement starts.‎ In the event of a capital reduction within the capital range, the board of directors has to determine the use of the reduction amount, to the extent necessary.

In a capital increase within the capital range, the board of directors is authorized by our articles of association to ‎withdraw or to limit the pre-emptive subscription rights of shareholders, and to allocate them to third parties or to us, ‎in the event that the newly issued shares are issued under the following circumstances:

· if the issue price of the new registered shares is determined by reference to the market price;‎
· for raising of equity capital (including private placements) in a fast and flexible manner, which would not be ‎possible, or might only be possible with great difficulty or delays or at significantly less favorable ‎conditions, without the exclusion of the statutory pre-emptive subscription rights of the existing ‎shareholders;‎
· for the acquisition of an enterprise, parts of an enterprise or participations, for the acquisition of products, ‎intellectual property or licenses by or for investment projects of the Company or any of its group ‎companies, or for the financing or refinancing of any of such transactions through a placement of shares;‎
· for purposes of broadening the shareholder constituency of the Company in certain geographic, financial ‎or investor markets, for purposes of the participation of strategic partners, including financial investors, or in connection with the listing ‎of new shares on domestic or foreign stock exchanges;‎
· for purposes of granting an over-allotment option or an option to purchase additional shares in a ‎placement or sale of shares to the respective initial purchaser(s) or underwriter(s);‎
· for the participation of members of the board of directors, members of the executive committee, ‎employees, contractors, consultants or other persons performing services for the benefit of the Company ‎or any of its group companies;‎
· following a shareholder or a group of shareholders acting in concert having accumulated shareholdings in ‎excess of 20% of our share capital registered in the Commercial Register without having submitted to all ‎other shareholders a takeover offer recommended by the board of directors;
· for the defense of an actual, threatened or potential takeover bid, that the board of directors, upon ‎consultation with an independent financial adviser retained by it, has not recommended to the ‎shareholders acceptance on the basis that the board of directors has not found the takeover bid to be ‎financially fair to the shareholders or not to be in the Company's interest; or

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· for other valid grounds in the sense of Article 652b para. 2 of the CO.‎

This authorization to withdraw or to limit the pre-emptive subscription of shareholders is exclusively linked to our capital range. If the capital range lapses for any reasons, such as if an ordinary capital increase is completed, the authorization to withdraw or to limit the pre-emptive subscription rights lapses ‎simultaneously with the capital range.‎

We have agreed not to use the foregoing authorization to ‎withdraw or to limit the pre-emptive subscription rights of shareholders, and to allocate them to third parties or to us, in certain circumstances. Specifically, we will not restrict the preemptive rights of Redmile Group, LLC ("Redmile") or its affiliates based on Article 4a(4)(g) of the articles of association or restrict the advance subscription rights of Redmile or its affiliates based on Article 4c(3) of the articles of association as long as (i) Redmile (including its affiliates and any other person or entity forming a "group" (as defined in Rule 13d-5 under the Exchange Act)) does not directly or indirectly control, own or have the right to control or own, collectively, shares representing more than 20% of the Company's share capital or (ii) Redmile (including its affiliates and any other person or entity forming a "group" (as defined in Rule 13d-5 under the Exchange Act)) directly or indirectly controls, owns or has the right to control or own, collectively, shares representing more than 20% of the Company's share capital but the board of directors determines that Redmile does not have an intent to effect a change of control of the Company.

Our Conditional Share Capital

Conditional Share Capital for Warrants and Convertible Bonds

Our nominal share capital may be increased, including to prevent takeovers and changes in control, by a maximum ‎aggregate amount of CHF 1,432,776.24 through the issuance of not more than 17,909,703 common shares, which ‎would have to be fully paid-in, each with a par value of CHF 0.08 per share, by the exercise of option and ‎conversion rights granted in connection with warrants, convertible bonds or similar instruments of the Company or ‎one of our subsidiaries. Shareholders will not have pre-emptive subscription rights in such circumstances, but will ‎have advance subscription rights to subscribe for such warrants, convertible bonds or similar instruments. The ‎holders of warrants, convertible bonds or similar instruments are entitled to the new shares upon the occurrence of ‎the applicable conversion feature.‎

When issuing convertible bonds, warrants or similar instruments, the board of directors is authorized to withdraw or ‎to limit the advance subscription right of shareholders:‎

· for the purpose of financing or refinancing, or the payment for, the acquisition of enterprises, parts of ‎enterprises, participations, intellectual property rights, licenses or investments;‎
· if the issuance occurs in domestic or international capital markets, including private placements;‎
· following a shareholder or a group of shareholders acting in concert having accumulated shareholdings in ‎excess of 20% of the share capital registered in the Commercial Register without having submitted to all ‎other shareholders a takeover offer recommended by the board of directors;
· for the defense of an actual, threatened or potential takeover bid that the board of directors, upon ‎consultation with an independent financial adviser retained by it, has not recommended to the ‎shareholders to accept on the basis that the board of directors has not found the takeover bid to be ‎financially fair to the shareholders or not to be in the Company's interest; or
· if the convertible bonds, warrants or similar instruments are issued on appropriate terms.‎

To the extent that the advance subscription rights are withdrawn or limited, (i) the term to exercise the convertible bonds, warrants or ‎similar instruments may not exceed fifteen years from the date of issue of the respective instrument and (ii) the conversion, exchange or exercise price of ‎the convertible bonds,

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warrants or similar instruments has to be set with reference to or be subject to change based ‎upon the valuation of the Company's equity or market conditions.‎

Conditional Share Capital for Equity Incentive Plans

Our nominal share capital may, to the exclusion of the pre-emptive subscription rights and advance subscription ‎rights of shareholders, be increased by a maximum aggregate amount of CHF 936,000 through the (direct or ‎indirect) issuance of not more than 11,700,000 common shares, which would have to be fully paid-in, each with a ‎par value of CHF 0.08 per share, by the exercise or mandatory exercise of options, other rights to receive or acquire shares or conversion rights that ‎have been granted to or imposed on employees, members of the board of directors, contractors or consultants of the Company or ‎of one of our subsidiaries or other persons providing services to the Company or to a subsidiary through one or ‎more equity incentive plans created by the board of directors.‎

Uncertificated Securities

Our shares are in the form of uncertificated securities (droits-valeurs, within the meaning of Article 973c of the CO). ‎In accordance with Article 973c of the CO, we maintain a non-public register of uncertificated securities ‎‎(registre des droits-valeurs). We may at any time convert uncertificated securities into share certificates (including ‎global certificates), one kind of certificate into another, or share certificates (including global certificates) into ‎uncertificated securities. Following entry in the share register, a shareholder may at any time request from us a ‎written confirmation in respect of his or her shares. Shareholders are not entitled, however, to request the conversion ‎and/or printing and delivery of share certificates. We may print and deliver certificates for shares at any time.‎

General Meeting of Shareholders

Ordinary/Extraordinary Meetings, Powers

The general meeting of shareholders is our supreme corporate body. Under Swiss law, an annual general meeting of ‎shareholders must be held annually within six months after the end of a corporation's financial year. In our case, ‎this generally means on or before June 30. In addition, extraordinary general meetings of shareholders may be held.‎

A general meeting of shareholders may take place in or outside Switzerland and at different places simultaneously if the votes of the participants are immediately transmitted to all meeting venues (multilocal shareholders' meeting). The board of directors may allow shareholders that are not present at the meeting venue of the general meeting of shareholders to participate and exercise their rights electronically ("hybrid shareholder meeting"). Our articles of association also allow for general meetings of shareholders without a physical meeting venue but that takes place using electronic means ("virtual shareholder meeting").

According to our articles of association, the following powers are vested exclusively in the general meeting of shareholders:

· adopting and amending the articles of association, including the change of a company's purpose or domicile;
· electing the members of the board of directors, the chairperson of the board of directors, the members of the compensation committee, the auditors and the independent proxy;
· approving the business report, the annual statutory and consolidated financial statements, and deciding on the allocation of profits as shown on the balance sheet, in particular with regard to dividends;
· determining the interim dividend and approving the requisite interim financial statements;

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· resolving on the repayment of the statutory capital reserve (réserve légale issue du capital);
· approving the aggregate amount of compensation of members of the board of directors and the executive committee;
· discharging the members of the board of directors and the executive committee from liability with respect to their conduct of business;
· resolving on the delisting of the company's equity securities;
· approving the report on non-financial matters (if applicable);
· dissolving a company with or without liquidation; and
· deciding matters reserved to the general meeting of shareholders by law or the articles of association or submitted to it by the board of directors.

An extraordinary general meeting of shareholders may be called by a resolution of the board of directors or the ‎general meeting of shareholders or, under certain circumstances, by a company's auditors, liquidator or the ‎representatives of bondholders, if any. In addition, our articles of association require the board of directors to convene an extraordinary ‎general meeting of shareholders if shareholders representing at least 5% of our share capital or voting rights request such general ‎meeting of shareholders in writing. A request for an extraordinary general meeting of shareholders must set forth the items to be discussed and the proposals to be ‎acted upon. Further, the board of directors must convene an extraordinary general meeting of shareholders and propose ‎financial restructuring measures if, based on our stand-alone annual statutory balance sheet, half of our share ‎capital and statutory reserves are not covered by our assets and a contemplated restructuring measure falls within the competence of the general meeting of shareholders.‎

Voting and Quorum Requirements

Shareholder resolutions and elections (including elections of members of the board of directors) require the ‎affirmative vote of the majority of shares represented at the general meeting of shareholders, unless ‎otherwise stipulated by law or our articles of association.‎

Under our articles of association, a resolution of the general meeting of shareholders passed by ‎two-thirds of the votes and the majority of the par value of the shares, each as ‎represented at the meeting, is required for:‎

· amending the Company's corporate purpose;
· creating shares with preference rights;
· cancelling or amending the transfer restrictions of shares;
· creating conditional share capital or a capital range;
· increasing share capital out of equity, against contributions in-kind, by set-off against a claim or granting of specific benefits;
· limiting or withdrawing shareholder's pre-emptive subscription rights;
· changing the currency of the share capital;
· introducing a casting vote of the chairperson at the general meeting of shareholders;
· changing the Company's domicile;

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· delisting the company's equity securities;
· introducing an arbitration clause in the articles of association;
· resolving on the consolidation of shares (reverse split);
· amending or repealing the voting and recording restrictions, the provision setting a maximum board size, the indemnification provision for the board of directors and the executive committee or the forum selection clause set forth in our articles of association;
· converting registered shares into bearer shares;
· removing the chairperson or any member of the board of directors before the end of his or her term of office; and
· dissolving or liquidating the Company.

The same voting requirements apply to resolutions regarding transactions among corporations based on Switzerland's Federal Act on Mergers, Demergers, Transformations and the Transfer of Assets of 2003, as amended (the "Swiss Merger Act"). See "-Articles of Association-Compulsory Acquisitions; Appraisal Rights."

In accordance with Swiss law and generally accepted business practices, our articles of association do not provide for quorum requirements generally applicable to general meetings of shareholders. To this extent, our practice varies from NYSE listing standards, which require an issuer to provide in its bylaws for a generally applicable quorum and that such quorum may not be less than one-third of the outstanding voting shares.

Notice

General meetings of shareholders must be convened by the board of directors at least 20 days before the date of ‎the meeting. The general meeting of shareholders is convened by way of a notice appearing in our official ‎publication medium, currently the Swiss Official Gazette of Commerce, or by including the notice in the proxy statement. Registered shareholders may also be ‎informed in a form that allows proof by text. The notice of a general meeting of shareholders must state the date, the starting and end time, the form and location of the meeting, the items on the ‎agenda, the motions of the board of directors or of any shareholders including a short explanation, as well as the name and address of the independent representative. A ‎resolution on a matter which is not on the agenda may not be passed at a general meeting of shareholders, except ‎for motions to convene an extraordinary general meeting of shareholders or to initiate a special investigation, on ‎which the general meeting of shareholders may vote at any time. No previous notification is required for motions ‎concerning items included in the agenda or for debates that do not result in a vote.‎

All owners or representatives of our shares may, if no objection is raised, hold a general meeting of shareholders without complying with the formal requirements for convening general meetings of shareholders (a universal meeting). This universal meeting of shareholders may discuss and pass binding resolutions on all matters within the purview of the general meeting of shareholders, provided that the owners or representatives of all the shares are present at the meeting.

Agenda Requests

Pursuant to our articles of association, one or more shareholders whose combined shareholdings ‎represent at least 0.5% of the share capital or the voting rights ‎may request that an item be included in the agenda for a general meeting of shareholders or that a proposal relating to an agenda item be included in the notice convening the general meeting of shareholders.

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To be timely, the ‎shareholder's request must be received by us generally at least 90 calendar days in advance of the meeting. The ‎request must be made in writing and contain, for each of the agenda items, the following information:‎

· a brief description of the business desired to be brought before the general meeting of shareholders and the reasons for conducting such business at the general meeting of shareholders;
· the motions regarding the agenda item;
· the name and address, as they appear in the share register, of the shareholder proposing such business;
· the number of shares which are beneficially owned by such shareholder (including documentary support of such beneficial ownership);
· the dates upon which the shareholder acquired such shares;
· any material interest of the proposing shareholder in the proposed business;
· a statement in support of the matter; and
· all other information required under the applicable laws and stock exchange rules.

In addition, if the shareholder intends to solicit proxies from the shareholders of a company, such shareholder shall notify the company of this intent in accordance with applicable SEC rules.

Our business report, the compensation report and the auditor's report must be published or otherwise made accessible to our ‎shareholders no later than 20 days prior to the general meeting of shareholders. Shareholders ‎of record may be notified of this in writing.

Minutes

We are required to make available the resolutions and election results of our general meeting of shareholders electronically within 15 calendar days after the meeting. In addition, each shareholder may request that the minutes be made available to them within 30 calendar days after the meeting.

Voting Rights

Each of our common shares entitles a holder to one vote. The common shares are not divisible. The right to vote and the other rights of share ownership may only be exercised by shareholders (including any nominees) or usufructuaries who are entered in the share register at a cut-off date determined by the board of directors. Those entitled to vote in the general meeting of shareholders may be represented by the independent proxy holder (annually elected by the general meeting of shareholders), by its legal representative or by any other person with written authorization to act as proxy. The chairperson has the power to decide whether to recognize a power of attorney.

Our articles of association contain provisions that prevent investors from acquiring voting rights exceeding 15% of our issued share capital. Specifically, if an individual or legal entity acquires common shares and, as a result, directly or indirectly, has voting rights with respect to more than 15% of the registered share capital recorded in the Commercial Register, the registered shares exceeding the limit of 15% shall be entered in the share register as shares without voting rights (limitation à l'inscription). This restriction applies equally to parties acting in concert and to shares held or acquired via a nominee, including via Cede & Co., New York (or any successor), as the nominee of The Depository Trust Company ("DTC"), New York, acting in its capacity as clearing nominee. Specifically, if shares are being held by a nominee for third-party beneficiaries, which control (alone or together with third parties) voting rights with respect to more than 15% of the share capital recorded in the Commercial Register, our articles of association

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provide that the board of directors may cancel the registration of the shares with voting rights held by such nominee in excess of the limit of 15%. Furthermore, our articles of association contain provisions that allow the board of directors to make the registration with voting rights of shares held by a nominee subject to conditions, limitations and reporting requirements or to impose or adjust such conditions, limitations and requirements once registered. However, any shareholders who held more than 15% prior to our initial public offering remain registered with voting rights for such shares. Furthermore, the board of directors may in special cases approve exceptions to these restrictions.

Dividends and Other Distributions

Our board of directors may propose to shareholders that a dividend or interim dividend or other distribution be paid but cannot itself ‎authorize the distribution. Dividend and interim dividend payments require a resolution passed by a majority of the shares ‎represented at a general meeting of shareholders. In addition, our auditors must confirm that the dividend proposal ‎of our board of directors conforms to Swiss statutory law and our articles of association.‎

Under Swiss law, we may pay dividends only if we have sufficient distributable profits from the previous or current business ‎year (bénéfice résultant du bilan) or brought forward from the previous business years (report des bénéfices), or if we ‎have distributable capital reserves (réserve légale issue du capital), each as evidenced by audited stand-alone ‎statutory annual or interim financial statements prepared pursuant to Swiss law, and after allocations to reserves required by Swiss law and ‎by the articles of association have been deducted.

Under the CO, at least 5% of our annual profit must be retained as statutory profit reserve (réserve légale). If there is a loss carried forward, such loss must be eliminated before allocation to the statutory profit reserve. The statutory profit reserve shall be accumulated until it reaches, together with the statutory capital reserve, 50% of our share capital recorded in the Commercial Register. In addition, we have to allocate, among other things, the net proceeds of share issuances to the statutory capital reserve. The CO permits us to accrue ‎additional reserves. Further, a purchase of our own shares (whether by us or a subsidiary) reduces the distributable reserves in an amount corresponding to the purchase price of such own shares. Finally, the CO under ‎certain circumstances requires the creation of revaluation reserves which are not distributable.‎

Distributions out of issued share capital (i.e., the aggregate par value of our issued shares) are not allowed and may ‎be made only by way of an ordinary capital reduction or within a capital range that (also) allows for a capital reduction (see "Description of Share Capital and Articles of Association-Articles of Association-Ordinary Capital Increase, Capital Range and Conditional Share Capital"). An ordinary capital reduction requires a resolution passed by a‎ majority of the shares represented at a general meeting of shareholders. The board of directors must publish a call to creditors in the Swiss Official Gazette of Commerce in which creditors are advised that they may request, subject to certain conditions, security for their claims within ‎30 days of the publication of the creditor call. A licensed audit expert must then confirm, based on the results of the call to creditors, that the claims of the creditors remain fully ‎covered despite the reduction in our share capital recorded in the Commercial Register. If all requirements for an ordinary capital reduction have been met, the board of directors has to amend the articles of association in a public deed. Our share capital may be ‎reduced to a level below CHF 100,000 only if and to the extent that at the same time the statutory minimum share capital of ‎CHF 100,000 is reestablished by sufficient new fully paid-up capital. An ordinary capital reduction must be completed within six months after the resolution of the general meeting of shareholders.‎

Our board of directors determines the date on which the dividend entitlement starts. Dividends are usually due and ‎payable shortly after the shareholders have passed the resolution approving the payment, but shareholders may ‎also resolve at the annual general meeting of shareholders to pay dividends in quarterly or other installments.‎

Transfer of Shares

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Shares in uncertificated form (droits-valeurs) may only be transferred by way of assignment. Shares or the beneficial interest in shares, as applicable, credited in a securities account may only be transferred when a credit of the relevant intermediated securities to the acquirer's securities account is made in accordance with applicable rules. Our articles of association provide that in the case of securities held with an intermediary such as a registrar, transfer agent, trust corporation, bank or similar entity, any transfer, grant of a security interest or usufructuary right in such intermediated securities and the appurtenant rights associated therewith requires the cooperation of the intermediary in order for such transfer, grant of a security interest or usufructuary right to be valid against us.

Voting rights may be exercised only after a shareholder has been entered in the share register (registre des actions) with his or her name and address (in the case of legal entities, the registered office) as a shareholder with voting rights. For a discussion of the restrictions applicable to the control and exercise of voting rights, see "Description of Share Capital and Articles of Association-Articles of Association-Voting Rights."

Inspection of Books and Records

Under the CO, a shareholder has a right to inspect the share register with respect to his or her own shares and ‎otherwise to the extent necessary to exercise his or her shareholder rights. No other person has a right to inspect the ‎share register. Shareholders holding in the aggregate at least 5% of our nominal share capital or of our voting rights have the right to inspect our books and correspondence, subject to the safeguarding of our business secrets and other legitimate interests. Our board of directors is required to decide on an inspection request within four months after receipt of such request. Denial of the request will need to be justified in writing. If an inspection request is denied by the board of directors, shareholders may request the order of an inspection by the court within 30 days. See "Comparison of Swiss Law and Delaware Law-Inspection of books and ‎records."‎

Special Investigation

If a shareholder has exercised its information or inspection rights, ‎such shareholder may propose to the general meeting of shareholders that specific facts be examined by a special ‎examiner in a special investigation. If the general meeting of shareholders approves the proposal, we or any ‎shareholder may, within 30 calendar days after the general meeting of shareholders, request a court at our registered ‎office (currently Epalinges, Canton of Vaud, Switzerland) to appoint a special examiner. If the general meeting of ‎shareholders rejects the request, one or more shareholders representing at least 5% of our share capital or voting rights may request that the court appoint a special ‎examiner. The court will issue such an order if the petitioners can demonstrate that ‎members of the board of directors or our executive committee infringed the law or our articles of association and that such violation is suitable to cause a damage to the Company or the shareholders. The costs of the investigation would generally be ‎allocated to us and only in exceptional cases to the petitioners.‎

Compulsory Acquisitions; Appraisal Rights

Business combinations and other transactions that are governed by the Swiss Merger Act (i.e., mergers, demergers, ‎transformations and certain asset transfers) are binding on all shareholders. A statutory merger or demerger requires ‎approval of two-thirds of the shares represented at a general meeting of shareholders and the majority of ‎the par value of the shares represented.‎

If a transaction under the Swiss Merger Act receives all of the necessary consents, all shareholders are compelled to participate in such transaction.

Swiss corporations may be acquired by an acquirer through the direct acquisition of the shares of the Swiss corporation. The Swiss Merger Act provides for the possibility of a so-called "cash-out" or "squeeze-out" merger with the approval of holders of 90% of the issued shares. In these limited circumstances, minority shareholders of the corporation being acquired may be compensated in a form other than through shares of the acquiring corporation (for instance, through cash or securities of a parent corporation of the acquiring corporation or of another corporation). For business combinations effected in

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the form of a statutory merger or demerger and subject to Swiss law, the Swiss Merger Act provides that if equity rights have not been adequately preserved or compensation payments in the transaction are unreasonable, a shareholder may request the competent court to determine a reasonable amount of compensation.

In addition, under Swiss law, the sale of "all or substantially all of our assets" by us may require the approval of ‎two-thirds of the number of shares represented at a general meeting of shareholders and the majority of ‎the par value of the shares represented. Whether a shareholder resolution is required depends on the particular ‎transaction, including whether the following test is satisfied:‎

· a core part of our business is sold without which it is economically impracticable or unreasonable to continue to operate the remaining business;
· our assets, after the divestment, are not invested in accordance with our corporate purpose as set forth in the articles of association; and
· the proceeds of the divestment are not earmarked for reinvestment in accordance with our corporate purpose but, instead, are intended for distribution to our shareholders or for financial investments unrelated to our corporate purpose.

A shareholder of a Swiss corporation participating in certain major corporate transactions may, under certain circumstances, be entitled to appraisal rights. As a result, such shareholder may, in addition to the consideration (be it in shares or in cash) receive an additional amount to ensure that the shareholder receives the fair value of the shares held by the shareholder. Following a statutory merger or demerger, pursuant to the Swiss Merger Act, shareholders can file an appraisal action against the surviving company. If the consideration is deemed inadequate, the court will determine an adequate compensation payment.

Board of Directors

Our articles of association provide that the board of directors shall consist of at least three and not more than nine ‎members.‎

The members of the board of directors and the chairperson are elected annually by the general meeting of shareholders for a period until the completion of the subsequent annual general meeting of shareholders and are eligible for re-election. Each member of the board of directors must be elected individually.

Powers

According to our articles of association, the board of directors has the following non-delegable and inalienable powers and duties:‎

· the ultimate direction of the business of the Company and issuing of the relevant directives;‎
· laying down the organization of the Company;‎
· formulating accounting procedures, financial controls and financial planning;‎
· nominating and removing persons entrusted with the management and representation of the Company ‎and regulating the power to sign for the Company;‎
· the ultimate supervision of those persons entrusted with management of the Company, with particular ‎regard to adherence to law, our articles of association, and regulations and directives of the Company;‎

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· preparing the annual report, the compensation report and, if applicable, the report on non-financial matters and other reports as required by law;
· preparing for the general meeting of ‎shareholders and carrying out its resolutions; and
· submitting a petition for debt-restructuring moratorium and informing the court in case of over-indebtedness.‎

The board of directors may, while retaining such non-delegable and inalienable powers and duties, delegate some of ‎its powers, in particular direct management, to a single or to several of its members, committees or to third parties ‎‎(such as executive officers) who need be neither members of the board of directors nor shareholders. Pursuant to ‎Swiss law and our articles of association, details of the delegation and other procedural rules such as quorum ‎requirements have been set in the organizational rules established by the board of directors.‎

Indemnification of Executive Officers and Directors

Subject to Swiss law, our articles of association provide for indemnification of the existing and former members of the board of directors and the executive committee and their heirs, executors and administrators, against liabilities arising in connection with the performance of their duties in such capacity, and permits us to advance the expenses of defending any act, suit or proceeding to our directors and executive officers to the extent not included in insurance coverage or advanced by third parties.

In addition, under general principles of Swiss employment law, an employer may be required to indemnify an employee against losses and expenses incurred by such employee in the proper execution of his or her duties under the employment agreement with the employer. See "Comparison of Swiss Law and Delaware Law-Indemnification of directors and executive officers and limitation of liability."

We have entered into indemnification agreements with each of the members of our board of directors and executive officers.

Conflicts of Interest, Management Transactions

The members of the board of directors and the executive committee are required to immediately and fully inform the board of directors about conflicts of interests concerning them. The board of directors is furthermore required to take measures in order to protect the interests of the company. More generally, the CO requires our directors and executive officers to safeguard the Company's interests and imposes a duty of ‎loyalty and duty of care on our directors and executive officers. This rule is generally understood to disqualify ‎directors and executive officers from participation in decisions that directly affect them. Our directors and ‎executive officers are personally liable to us for breaches of these obligations. In addition, Swiss law contains ‎provisions under which directors and all persons engaged in the Company's management are liable to the ‎Company, each shareholder and the Company's creditors for damages caused by an intentional or negligent ‎violation of their duties. Furthermore, Swiss law contains a provision under which payments made to any of the ‎Company's shareholders or directors or any person related to any such shareholder or director, other than payments ‎made at arm's length, must be repaid to the Company if such shareholder or director acted in bad faith.‎

Our board of directors has adopted a Code of Business Conduct and Ethics and other policies that cover a broad ‎range of matters, including the handling of conflicts of interest.‎

Principles of the Compensation of the Board of Directors and the Executive Committee

Pursuant to Swiss law, the aggregate amount of compensation of the ‎board of directors and the persons whom the board of directors has, fully or partially, entrusted with the ‎management (which we refer to as our "executive committee") of the Company has to be submitted to our shareholders for approval each

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year. Our executive committee currently comprises the Chief Executive Officer, the Chief Financial Officer, the Chief Scientific Officer and the Swiss Managing Director.‎

The board of directors must issue, on an annual basis, a written compensation report that must be reviewed by our ‎auditors. The compensation report must disclose, among other things, all compensation granted by the Company, directly or indirectly, ‎to current members of the board of directors and the executive committee and, to the extent related to their former ‎role within the Company or not on customary market terms, to former members of the board of directors and ‎former executive officers.‎ The disclosure concerning compensation, loans and other forms of indebtedness must include the aggregate amount for the board of directors and the executive committee, respectively, as well as the particular amount for each member of the board of directors and for the highest-paid executive officer, specifying the name and function of each of these persons. If variable compensation is approved prospectively, as is currently the case with the Company, our board of directors must submit the compensation report to a non-binding vote of the general meeting of shareholders.

We are prohibited from granting certain forms of compensation to members of our board of directors and executive committee, such as:

· severance payments (compensation due until the termination of a contractual relationship does not qualify as severance payment);
· advance compensation;
· incentive fees for the acquisition or transfer of companies, or parts thereof, by the Company or by companies being, directly or indirectly, controlled by us;
· loans, other forms of indebtedness, pension benefits not based on occupational pension schemes and performance-based compensation not provided for in the articles of association; and
· equity-based compensation not provided for in the articles of association.

Compensation to members of the board of directors and the executive committee for activities in entities that are, directly or indirectly, controlled by the Company is prohibited if (i) the compensation would be prohibited if it were paid directly by the Company, (ii) the articles of association do not provide for it, or (iii) the compensation has not been approved by the general meeting of shareholders.

Every year, the general meeting of shareholders has to vote on the proposals of the board of directors with respect to:

· the maximum aggregate amount of compensation of the board of directors for the term of office until the next annual general meeting of shareholders; and
· the maximum aggregate amount of fixed compensation of the executive committee for the following financial year; and
· the maximum aggregate amount of variable compensation of the executive committee for the current financial year.

The board of directors may submit for approval at the general meeting of shareholders deviating or additional proposals relating to the same or different periods.

If, at the general meeting of shareholders, the shareholders do not approve a compensation proposal of the board of directors, the board of directors must prepare a new proposal, taking into account all relevant factors, and submit the new proposal for approval by the same general meeting of shareholders, at a subsequent extraordinary general meeting of shareholders or the next annual general meeting of shareholders.

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If we appoint new members of the executive committee after the general meeting of shareholders has approved the compensation of the executive committee for the relevant period and such compensation is insufficient to also cover the new members' compensation, our articles of association allow us to pay each new member an amount not exceeding the aggregate amount of (maximum) compensation of the executive committee last approved.

In addition to fixed compensation, members of the board of directors and the executive committee may be paid variable compensation, depending on the achievement of certain performance criteria. The performance criteria may include individual targets, targets of the Company or parts thereof and targets in relation to the market, other companies or comparable benchmarks, taking into account the position and level of responsibility of the recipient of the variable compensation. The board of directors or, where delegated to it, the compensation committee shall determine the relative weight of the performance criteria and the respective target values as well as their achievement.

Compensation may be paid or granted in the form of cash, shares, financial instruments, in kind, or in the form of other types of benefits. The board of directors or, where delegated to it, the compensation committee shall determine grant, vesting, exercise and forfeiture conditions.

Borrowing Powers

Neither Swiss law nor our articles of association restricts our power to borrow and raise funds. The decision to borrow funds is made by or under the direction of our board of directors, and no approval by the shareholders is required in relation to any such borrowing.

Repurchases of Shares and Purchases of Own Shares

The CO limits our ability to repurchase and hold our own shares. We and our subsidiaries may repurchase shares only to the extent that (i) we have freely distributable reserves in the amount of the purchase price; and (ii) the aggregate par value of all shares held by us does not exceed 10% of our share capital. Pursuant to Swiss law, where shares are acquired in connection with a transfer restriction set out in the articles of association, the foregoing upper limit is 20%. If we own shares that exceed the threshold of 10% of our share capital, the excess must be sold or cancelled by means of a capital reduction within two years.

Shares held by us or our subsidiaries are not entitled to vote at the general meeting of shareholders but are entitled to the economic benefits applicable to the shares generally, including dividends and pre-emptive subscription rights in the case of share capital increases.

In addition, selective share repurchases are only permitted under certain circumstances. Within these limitations, as is customary for Swiss corporations, we may, subject to applicable law, purchase and sell our own shares from time to time in order to meet imbalances of supply and demand, to provide liquidity and to even out variances in the market price of shares.

Notification and Disclosure of Substantial Share Interests

The disclosure obligations generally applicable to shareholders of Swiss corporations under the Federal Act on Financial Market Infrastructures and Market Conduct in Securities and Derivatives Trading, or the Financial Market Infrastructure Act (the "FMIA"), do not apply to us since our shares are not listed on a Swiss exchange.

Mandatory Bid Rules

The obligation of any person or group of persons that acquires more than one-third of a company's voting rights to submit a cash offer for all the outstanding listed equity securities of the relevant company at a minimum price pursuant to the FMIA does not apply to us since our shares are not listed on a Swiss exchange.

Nonresident or Foreign Owners

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Other than limitations that apply to all holders of our common shares, there are no limitations on the right of nonresident or foreign owners of our common shares from holdings or voting such common shares imposed by Swiss law or our articles of association.

Exchange Controls

Other than sanctions against specific countries, individuals, and organizations, there are no governmental laws, decrees, regulations or other legislation in Switzerland affecting the remittance of dividends, interest and other payments to nonresident holders of our common shares.

Stock Exchange Listing

Our common shares are listed on the NYSE under the symbol "ADCT."

The Depository Trust Company

Each person owning a beneficial interest in common shares held through DTC must rely on the procedures thereof and on institutions that have accounts therewith to exercise any rights of a holder of the shares.

Transfer Agent and Registrar of Shares

Our share register is kept by Computershare Trust Company, N.A., which acts as transfer agent and registrar. The share register reflects only record owners of our shares. Swiss law does not recognize fractional share interests.

Comparison of Swiss Law and Delaware Law

The Swiss laws applicable to Swiss corporations and their shareholders differ from laws applicable to ‎U.S. corporations and their shareholders. The following table summarizes significant differences in shareholder ‎rights pursuant to the provisions of the CO, by which our Company is governed, and the Delaware General Corporation Law applicable to companies ‎incorporated in Delaware and their shareholders. Please note that this is only a general summary of certain ‎provisions applicable to companies in Delaware. Certain Delaware companies may be permitted to exclude certain ‎of the provisions summarized below in their charter documents.‎

DELAWARE CORPORATE LAW ‎ ‎SWISS CORPORATE LAW
Mergers and similar arrangements
Under the Delaware General Corporation Law, with ‎certain exceptions, a merger, consolidation, sale, lease or ‎transfer of all or substantially all of the assets of a ‎corporation must be approved by the board of directors ‎and a majority of the outstanding shares entitled to vote ‎thereon. A shareholder of a Delaware corporation ‎participating in certain major corporate transactions may, ‎under certain circumstances, be entitled to appraisal rights ‎pursuant to which such shareholder may receive cash in ‎the amount of the fair value of the shares held by such ‎shareholder (as determined by a court) in lieu of the ‎consideration such shareholder would otherwise receive in ‎the transaction. The Delaware General Corporation Law ‎also provides that a parent corporation, by resolution of ‎its board of directors, may merge with any ‎ ‎Under Swiss law, with certain exceptions, a merger or a ‎demerger of the corporation or a sale of all or ‎substantially all of the assets of a corporation must be ‎approved by two-thirds of the voting rights represented ‎at the respective general meeting of shareholders as ‎well as the majority of the par value of shares ‎represented at such general meeting of shareholders. ‎A shareholder of a Swiss corporation participating in a ‎statutory merger or demerger pursuant to the Swiss ‎Merger Act (Loi sur la fusion) can file a lawsuit against ‎the surviving company. If the consideration is deemed ‎‎"inadequate," such shareholder may, in addition to the ‎consideration (be it in shares or in cash) receive an ‎additional amount to ensure that such shareholder ‎receives the fair value of the shares held by such ‎shareholder. Swiss law also provides that if the merger ‎agreement provides only for a ‎

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subsidiary, of ‎which it owns at least 90.0% of each class of capital ‎stock without a vote by the shareholders of such ‎subsidiary. Upon any such merger, dissenting ‎shareholders of the subsidiary would have appraisal ‎rights.‎ compensation payment, ‎at least 90% of all members in the transferring legal ‎entity who are entitled to vote shall approve the ‎merger agreement.‎
Shareholders' suits
Class actions and derivative actions generally are ‎available to shareholders of a Delaware corporation for, ‎among other things, breach of fiduciary duty, corporate ‎waste and actions not taken in accordance with ‎applicable law. In such actions, the court has discretion to ‎permit the winning party to recover attorneys' fees ‎incurred in connection with such action.‎ ‎Class actions and derivative actions as such are not ‎available under Swiss law. Nevertheless, certain actions ‎may have a similar effect. A shareholder is entitled to ‎bring suit against directors, officers or liquidators for ‎breach of their duties and claim the payment of the ‎company's losses or damages to the corporation and, ‎in some cases, to the individual shareholder. Likewise, ‎an appraisal lawsuit won by a shareholder may ‎indirectly compensate all shareholders. In addition, to ‎the extent that U.S. laws and regulations provide a ‎basis for liability and U.S. courts have jurisdiction, a ‎class action may be available.‎
Under Swiss law, the winning party is generally entitled ‎to recover a limited amount of attorneys' fees incurred ‎in connection with such action. The court has discretion ‎to permit the shareholder who lost the lawsuit to ‎recover attorneys' fees incurred to the extent that he or ‎she acted in good faith.‎
Shareholder vote on board and management compensation
Under the Delaware General Corporation Law, the board ‎of directors has the authority to fix the compensation of ‎directors, unless otherwise restricted by the certificate of ‎incorporation or bylaws.‎ Pursuant to Swiss law, the general meeting of ‎shareholders has the non-transferable right, amongst ‎others, to vote separately and bindingly on the ‎aggregate amount of compensation of the members of ‎the board of directors, of the executive committee and ‎of the advisory boards.‎ If variable compensation is approved for a future period rather than for a past period, the compensation report is subject to a non-binding vote of the general meeting of shareholders.
Annual vote on board renewal

Unless directors are elected by written consent in lieu of ‎an annual meeting, directors are elected in an annual ‎meeting of shareholders on a date and at a time ‎designated by or in the manner provided in the bylaws. ‎Re-election is possible.‎ ‎

Classified boards are permitted.‎

The general meeting of shareholders elects the ‎members of the board of directors, the chairperson of ‎the board of directors and the members of the ‎compensation committee individually and annually for ‎a term of office until the end of the following general ‎meeting of shareholders. Re-election is possible.‎
Indemnification of directors and executive officers and limitation of liability
The Delaware General Corporation Law provides that a ‎certificate of incorporation may contain a Under Swiss corporate law, an indemnification by the ‎corporation of a director or member of the

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provision ‎eliminating or limiting the personal liability of directors and officers ‎‎(but not other controlling persons) of the corporation for ‎monetary damages for breach of a fiduciary duty as a ‎director, except no provision in the certificate of ‎incorporation may eliminate or limit liability of:‎

· ‎

a director or officer for any breach of the duty of loyalty to the ‎corporation or its shareholders;‎

·

a director or officer for acts or omissions not in good faith or which involve ‎intentional misconduct or a knowing violation of ‎law;‎ ‎

·

a director for statutory liability for unlawful payment of dividends ‎or unlawful share purchase or redemption;

·

a director or officer for any transaction from which the director or officer derived an ‎‎improper personal benefit; or

·

an officer in any action by or in right of the corporation.‎

A Delaware corporation may indemnify any person who ‎was or is a party or is threatened to be made a party to ‎any proceeding, other than an action by or on behalf of ‎the corporation, because the person is or was a director or ‎officer, against liability incurred in connection with the ‎proceeding if the director or officer acted in good faith ‎and in a manner reasonably believed to be in, or not ‎opposed to, the best interests of the corporation, and the ‎director or officer, with respect to any criminal action or ‎proceeding, had no reasonable cause to believe his or her ‎conduct was unlawful.‎

‎executive ‎committee in relation to potential personal liability is ‎not effective to the extent the director or member of ‎the executive committee intentionally or negligently ‎violated his or her corporate duties towards the ‎corporation (certain views advocate that at least a ‎grossly negligent violation is required to exclude the ‎indemnification). Furthermore, the general meeting of ‎shareholders may discharge (release) the directors and ‎members of the executive committee from liability for ‎their conduct to the extent the respective facts are ‎known to shareholders. Such discharge is effective only ‎with respect to claims of the company and of those ‎shareholders who approved the discharge or who have ‎since acquired their shares in full knowledge of the ‎discharge. Most violations of corporate law are ‎regarded as violations of duties towards the corporation ‎rather than towards the shareholders. In addition, ‎indemnification of other controlling persons is not ‎permitted under Swiss corporate law, including ‎shareholders of the corporation.

The articles of association of a Swiss corporation may ‎also set forth that the corporation shall indemnify and ‎hold harmless, to the extent permitted by the law, the ‎directors and executive managers out of assets of the ‎corporation against threatened, pending or completed ‎actions.‎

Also, a corporation may enter into and pay for ‎directors' and officers' liability insurance, which may ‎cover negligent acts as well.‎

Unless ordered by a court, any foregoing indemnification ‎is subject to a determination that the director or officer ‎has met the applicable standard of conduct:‎

·

by a majority vote of the directors who are not ‎parties to the proceeding, even though less than a ‎quorum;‎

·

by a committee of directors designated by a majority ‎vote of the eligible directors, even though less than a ‎quorum;‎

·

by independent legal counsel in a written opinion if ‎there are no eligible directors, or if the eligible ‎directors so direct; or

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·

by the shareholders.‎

Moreover, a Delaware corporation may not indemnify a ‎director or officer in connection with any proceeding in ‎which the director or officer has been adjudged to be ‎liable to the corporation unless and only to the extent that ‎the court determines that, despite the adjudication of ‎liability but in view of all the circumstances of the case, ‎the director or officer is fairly and reasonably entitled to ‎indemnity for those expenses which the court deems ‎proper.‎

Directors' fiduciary duties

A director of a Delaware corporation has a fiduciary duty ‎to the corporation and its shareholders. This duty has two ‎components:‎

·

the duty of care; and

·

the duty of loyalty.‎

The duty of care requires that a director act in good faith, ‎with the care that an ordinarily prudent person would ‎exercise under similar circumstances. Under this duty, a ‎director must inform himself or herself of, and disclose to ‎shareholders, all material information reasonably ‎available regarding a significant transaction.‎

The duty of loyalty requires that a director act in a ‎manner he or she reasonably believes to be in the best ‎interests of the corporation. He or she must not use his or ‎her corporate position for personal gain or advantage. ‎This duty prohibits self-dealing by a director and ‎mandates that the best interest of the corporation and its ‎shareholders take precedence over any interest possessed ‎by a director, officer or controlling shareholder and not ‎shared by the shareholders generally. In general, actions ‎of a director are presumed to have been made on an ‎informed basis, in good faith and in the honest belief that ‎the action taken was in the best interests of the ‎corporation. However, this presumption may be rebutted ‎by evidence of a breach of one of the fiduciary duties.

Should such evidence be presented concerning a ‎transaction by a director, a director must prove the ‎procedural fairness of the transaction, and that the ‎transaction was of fair value to the corporation.‎

The board of directors of a Swiss corporation manages ‎the business of the corporation, unless responsibility for ‎such management has been duly delegated to the ‎executive committee based on organizational rules. ‎However, there are several non-transferable duties of ‎the board of directors:‎

· ‎

the overall management of the corporation and ‎the issuing of all necessary directives;‎

·

determination of the corporation's organization;‎

·

the organization of the accounting, ‎financial control and financial planning systems as ‎required for management of ‎the corporation;‎

·

the appointment and dismissal of persons ‎entrusted with managing and representing the ‎corporation;‎

·

the overall supervision of the persons entrusted with ‎managing the corporation, in particular with regard ‎to compliance ‎with the law, articles of association, ‎operational regulations and directives;‎

·

the compilation of the annual report, the ‎compensation report, the report on non-financial matters and any other reports required by law, the preparation for ‎the general meeting of the shareholders ‎and implementation of its ‎resolutions; and

·

the filing of an application for a debt restructuring moratorium and notification of the court in the event that the ‎company is over-indebted.‎

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The members of the board of directors must perform ‎their duties with all due diligence and safeguard the ‎interests of the corporation in good faith. They must ‎afford the shareholders equal treatment in equal ‎circumstances.

‎The duty of care requires that a director act in good ‎faith, with the care that an ordinarily prudent director ‎would exercise under like circumstances.

The members of the board of directors and the executive committee are required to immediately and fully inform the board of directors about conflicts of interests concerning them. The board of directors is furthermore required to take measures in order to protect the interests of the company.

The duty of loyalty requires that a director safeguard ‎the interests of the corporation and requires that ‎directors act in the interest of the corporation and, if ‎necessary, put aside their own interests. If there is a risk ‎of a conflict of interest, the board of directors must ‎take appropriate measures to ensure that the interests ‎of the company are duly taken into account.‎

The burden of proof for a violation of these duties is ‎with the corporation or with the shareholder bringing a ‎suit against the director.‎

The Swiss Federal Supreme Court has established a doctrine that restricts its review of a business decision if the decision has been taken following proper preparation, on an informed basis and without conflicts of interest.

Shareholder action by written consent
A Delaware corporation may, in its certificate of ‎incorporation, eliminate the right of shareholders to act ‎by written consent. Shareholders of a Swiss corporation may exercise ‎their voting rights in a general meeting of shareholders. ‎ Shareholders can only act by written consents if no shareholder requests a general meeting of shareholders. The articles of ‎association must allow for (independent) proxies to be ‎present at a general meeting of shareholders. The ‎instruction of such (independent) proxies may occur in ‎writing or electronically.‎
Shareholder proposals
A shareholder of a Delaware corporation has the right to ‎put any proposal before the annual meeting of ‎shareholders, provided it complies with the notice ‎provisions in the governing documents. A special meeting ‎may be called by the board of ‎

At any general meeting of shareholders, any ‎shareholder may put proposals to the meeting if the ‎proposal is part of an agenda item. No resolution may ‎be taken on proposals relating to the agenda items that ‎were not duly notified.

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directors or any other ‎person authorized to do so in the governing documents, ‎but shareholders may be precluded from calling special ‎meetings.‎

Unless the articles of association ‎provide for a lower threshold or for additional ‎shareholders' rights:

· ‎‎

shareholders together representing at least 5% of ‎the share capital or voting rights may demand that a general ‎meeting of shareholders be called for specific ‎agenda items and specific proposals; and

·

shareholders together representing shares with a ‎par value of at least 0.5% of the ‎share capital or the voting rights may demand ‎that an agenda item including a specific proposal, or a proposal with respect to an existing agenda item, ‎be put on the agenda for a scheduled general ‎meeting of shareholders, provided such request is ‎made with appropriate lead time.‎

Any shareholder can propose candidates for election as ‎directors or make other proposals within the scope of ‎an agenda item without prior written notice.‎

In addition, any shareholder is entitled, at a general ‎meeting of shareholders and without advance notice, to ‎‎(i) request information from the board of directors on ‎the affairs of the company (note, however, that the ‎right to obtain such information is limited), (ii) request ‎information from the auditors on the methods and ‎results of their audit, (iii) request that the general ‎meeting of shareholders resolve to convene an ‎extraordinary general meeting, or (iv) request that the ‎general meeting of shareholders resolve to appoint an ‎examiner to carry out a special examination ("examenspécial").‎
Cumulative voting
‎Under the Delaware General Corporation Law, ‎cumulative voting for elections of directors is not ‎permitted unless the corporation's certificate of ‎incorporation provides for it.‎ Cumulative voting is not permitted under Swiss ‎corporate law. Pursuant to Swiss law, shareholders can ‎vote for each proposed candidate, but they are not ‎allowed to cumulate their votes for single candidates. ‎An annual individual election of (i) all members of the ‎board of directors, (ii) the chairperson of the board of ‎directors, (iii) the members of the compensation ‎committee, (iv) the election of the independent proxy ‎for a term of office of one year (i.e., until the following ‎annual general meeting of shareholders), as well as the ‎vote on the aggregate amount of compensation of the ‎members of the board of directors, of the executive ‎committee and of the members of any ‎

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advisory board, ‎is mandatory for listed companies. Re-election is ‎permitted.‎
Removal of directors
A Delaware corporation with a classified board may be ‎removed only for cause with the approval of a majority ‎of the outstanding shares entitled to vote, unless the ‎certificate of incorporation provides otherwise.‎ A Swiss corporation may remove, with or without ‎cause, any director at any time with a resolution passed ‎by a majority of the shares represented at a general ‎meeting of shareholders. The articles of association ‎may require the approval by a supermajority of the ‎shares represented at a meeting for the removal of a ‎director.‎
Transactions with interested shareholders
The Delaware General Corporation Law generally ‎prohibits a Delaware corporation from engaging in certain ‎business combinations with an "interested shareholder" ‎for three years following the date that such person ‎becomes an interested shareholder. An interested ‎shareholder generally is a person or group who or which ‎owns or owned 15.0% or more of the corporation's ‎outstanding voting shares within the past three years.‎ No such rule applies to a Swiss corporation.‎
Dissolution; winding up
Unless the board of directors of a Delaware corporation ‎approves the proposal to dissolve, dissolution must be ‎approved by shareholders holding 100.0% of the total ‎voting power of the corporation. Only if the dissolution is ‎initiated by the board of directors may it be approved by ‎a simple majority of the corporation's outstanding shares. ‎Delaware law allows a Delaware corporation to include in ‎its certificate of incorporation a supermajority voting ‎requirement in connection with dissolutions initiated by ‎the board. A dissolution of a Swiss corporation requires the ‎approval by two-thirds of the voting rights represented ‎at the respective general meeting of shareholders as ‎well as the majority of the par value of shares ‎represented at such general meeting of shareholders. ‎The articles of association may increase the voting ‎thresholds required for such a resolution.‎
Variation of rights of shares
A Delaware corporation may vary the rights of a class of ‎shares with the approval of a majority of the outstanding ‎shares of such class, unless the certificate of ‎incorporation provides otherwise.‎

The general meeting of shareholders of a Swiss ‎corporation may resolve that preference shares be ‎issued or that existing shares be converted into ‎preference shares with a resolution passed by a ‎majority of the shares represented at the general ‎meeting of shareholders. Where a company has issued ‎preference shares, further preference shares conferring ‎preferential rights over the existing preference shares ‎may be issued only with the consent of both a special ‎meeting of the adversely affected holders of the ‎existing preference shares and of a general meeting of ‎all shareholders, unless otherwise provided in the ‎articles of association.‎‎

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Shares with preferential voting rights are not regarded ‎as preference shares for these purposes.‎

Amendment of governing documents
A Delaware corporation's governing documents may be ‎amended with the approval of a majority of the ‎outstanding shares entitled to vote, unless the certificate ‎of incorporation provides otherwise.

The articles of association of a Swiss corporation may ‎be amended with a resolution passed by a majority of ‎the shares represented at a general meeting of ‎shareholders, unless otherwise provided in the articles ‎of association.‎

There are a number of resolutions, such as an ‎amendment of the stated purpose of the corporation, ‎the introduction of a capital range and conditional capital ‎and the introduction of shares with preferential voting ‎rights that require the approval by two-thirds of the ‎votes and a majority of the par value of the ‎shares represented at such general meeting of ‎shareholders. The articles of association may increase ‎these voting thresholds.‎

Inspection of books and records
Shareholders of a Delaware corporation, upon written ‎demand under oath stating the purpose thereof, have the ‎right during the usual hours for business to inspect for any ‎proper purpose, and to obtain copies of list(s) of ‎shareholders and other books and records of the ‎corporation and its subsidiaries, if any, to the extent the ‎books and records of such subsidiaries are available to ‎the corporation.

Shareholders of a Swiss corporation holding in the aggregate at least 5% of the nominal share capital or voting rights have the right to inspect ‎books and records, subject to the safeguarding of the company's business secrets and other interests warranting protection. A ‎shareholder is only entitled to receive information to ‎the extent required to exercise his or her rights as a ‎shareholder. The board of directors has to decide on an inspection request within four months after receipt of such request. Denial of the request will need to be justified in writing. If the board of directors denies an inspection request, shareholders may request the order of an inspection by the court within 30 days.‎

A shareholder's right to inspect the share register is ‎limited to the right to inspect his or her own entry in the ‎share register.

Payment of dividends
The board of directors may approve a dividend without ‎shareholder approval. Subject to any restrictions ‎contained in its certificate of incorporation, the board ‎may declare and pay dividends upon the shares of its ‎capital stock either:‎ ‎ Dividend (including interim dividend) payments are subject to the approval of the ‎general meeting of shareholders. The board of directors ‎may propose to shareholders that a dividend shall be ‎paid but cannot itself authorize the distribution.‎

·

out of its surplus, or

·

in case there is no such surplus, out of its net profits for ‎the fiscal year in which the

Payments out of a corporation's share capital (in other ‎words, the aggregate par value of the corporation's ‎ shares) in the form of dividends are ‎not allowed and may be made only by way of a ‎

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dividend is declared ‎and/or the preceding fiscal year.

‎Shareholder approval is required to authorize capital ‎stock in excess of that provided in the charter. Directors ‎may issue authorized shares without shareholder ‎approval.‎

share ‎capital reduction. Dividends may be paid only from the ‎profits of the previous or current business year or brought forward ‎from previous business years or if the corporation has ‎distributable reserves, each as evidenced by the ‎corporation's audited stand-alone statutory balance ‎sheet prepared pursuant to Swiss law and after ‎allocations to reserves required by Swiss law and the ‎articles of association have been deducted.‎
Creation and issuance of new shares
All creation of shares require the board of directors to ‎adopt a resolution or resolutions, pursuant to authority ‎expressly vested in the board of directors by the ‎provisions of the company's certificate of incorporation.‎ All creation of shares require a shareholders' resolution. ‎The creation of a capital range or conditional share capital ‎requires at least two-thirds of the voting rights ‎represented at the general meeting of shareholders and ‎a majority of the par value of shares ‎represented at such meeting. The board of directors ‎may issue or cancel shares out of the capital range ‎during a period of up to five years by a maximum amount of 50% of the current share capital. Shares are created ‎and issued out of conditional share capital through the ‎exercise of options or of conversion rights that the ‎board of directors may grant to shareholders, creditors of bonds or similar debt ‎instruments, employees, contractors or consultants, directors of the company or another group company or third parties.‎

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities, which may be secured or unsecured and may be exchangeable for and/or convertible into other securities, including our common shares. The debt securities will be issued under one or more separate indentures between us and a designated trustee. The terms of each series of debt securities being offered, including the terms, if any, on which a series of debt securities may be convertible into or exchangeable for other securities, and the material terms of the indenture will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will set forth, to the extent required, the following terms of the debt securities in respect of which the prospectus supplement is delivered:

· the title of the series;
· the aggregate principal amount;
· the issue price or prices, expressed as a percentage of the aggregate principal amount of the debt securities;
· any limit on the aggregate principal amount;
· the date or dates on which principal is payable;
· the interest rate or rates (which may be fixed or variable) or, if applicable, the method used to determine such rate or rates;
· the date or dates on which interest, if any, will be payable and any regular record date for the interest payable;
· the place or places where principal and, if applicable, premium and interest, is payable;
· the terms and conditions upon which we may, or the holders may require us to, redeem or repurchase the debt securities;
· the denominations in which such debt securities may be issuable, if other than denomination of $1,000 or any integral multiple of that number;
· whether the debt securities are to be issuable in the form of certificated debt securities or global debt securities;
· the portion of principal amount that will be payable upon declaration of acceleration of the maturity date if other than the principal amount of the debt securities;
· the currency of denomination;
· the designation of the currency, currencies or currency units in which payment of principal and, if applicable, premium and interest, will be made;
· if payments of principal and, if applicable, premium or interest, on the debt securities are to be made in one or more currencies or currency units other than the currency of denominations, the manner in which exchange rate with respect to such payments will be determined;
· if amounts of principal and, if applicable, premium and interest may be determined by reference to an index based on a currency or currencies, or by reference to a commodity, commodity index, stock exchange index, or financial index, then the manner in which such amounts will be determined;

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· the provisions, if any, relating to any collateral provided for such debt securities;
· any events of default;
· the terms and conditions, if any, for conversion into or exchange for common shares;
· any depositaries, interest rate calculation agents, exchange rate calculation agents, or other agents; and
· the terms and conditions, if any, upon which the debt securities shall be subordinated in right of payment to other indebtedness of our company.

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DESCRIPTION OF WARRANTS

We may issue warrants to purchase our debt or equity securities. The warrants may be issued independently or together with any other securities and may be attached to, or separate from, such securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a warrant agent. The terms of any warrants being offered and a description of the material provisions of the applicable warrant agreement will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will set forth, to the extent required, the following terms of the warrants in respect of which the prospectus supplement is delivered:

· the title of such warrants;
· the aggregate number of such warrants;
· the price or prices at which such warrants will be issued;
· the currency or currencies in which the price of such warrants will be payable;
· the securities or other rights, including rights to receive payment in cash or securities based on the value, rate or price of one or more specified commodities, currencies, securities or indices, or any combination of the foregoing, purchasable upon exercise of such warrants;
· the price at which and the currency or currencies in which the securities or other rights purchasable upon exercise of such warrants may be purchased;
· the date on which the right to exercise such warrants shall commence and the date on which such right shall expire;
· if applicable, the minimum or maximum amount of such warrants which may be exercised at any one time;
· if applicable, the designation and terms of the securities with which such warrants are issued and the number of such warrants issued with each such security;
· if applicable, the date on and after which such warrants and the related securities will be separately transferable;
· information with respect to book-entry procedures, if any;
· if applicable, a discussion of any material United States federal income tax considerations; and
· any other terms of such warrants, including terms, procedures and limitations relating to the exchange and exercise of such warrants.

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DESCRIPTION OF SUBSCRIPTION RIGHTS

We may issue subscription rights to purchase our securities. The subscription rights may be issued independently or together with any other securities, may be attached to, or separate from, such securities and may or may not be transferable by the shareholder receiving the subscription rights. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any unsubscribed securities after such offering. The terms of any subscription rights being offered will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will set forth, to the extent required, the following terms of the subscription rights in respect of which the prospectus supplement is delivered:

· the exercise price;
· the aggregate number of rights to be issued;
· the type and number of securities purchasable upon exercise of each right;
· the procedures and limitations relating to the exercise of the rights;
· the date upon which the exercise of rights will commence;
· the record date, if any, to determine who is entitled to the rights;
· the expiration date;
· the extent to which the rights are transferable;
· information regarding the trading of rights, including the stock exchanges, if any, on which the rights will be listed;
· the extent to which the subscription rights may include an over-subscription privilege with respect to unsubscribed securities;
· if appropriate, a discussion of material U.S. federal income tax considerations;
· if applicable, the material terms of any standby underwriting or purchase arrangement entered into by us in connection with the offering of the rights; and
· any other material terms of the rights.

If fewer than all of the subscription rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than shareholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby arrangements, as described in the applicable prospectus supplement.

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DESCRIPTION OF PURCHASE CONTRACTS

We may issue purchase contracts for the purchase or sale of debt or equity securities issued by us or securities of third parties, a basket of such securities, an index or indices of such securities or any combination of the above as specified in the applicable prospectus supplement, currencies or commodities.

Each purchase contract will entitle the holder thereof to purchase or sell, and obligate us to sell or purchase, on specified dates, such securities, currencies or commodities at a specified purchase price, which may be based on a formula, all as set forth in the applicable prospectus supplement. A purchase by us or any of our subsidiaries of common shares pursuant to any such purchase contract shall be subject to certain restrictions under Swiss law that generally apply to a repurchase of shares. We may, however, satisfy our obligations, if any, with respect to any purchase contract by delivering the cash value of such purchase contract or the cash value of the property otherwise deliverable or, in the case of purchase contracts on underlying currencies, by delivering the underlying currencies, as set forth in the applicable prospectus supplement. The applicable prospectus supplement will also specify the methods by which the holders may purchase or sell such securities, currencies or commodities and any acceleration, cancellation or termination provisions or other provisions relating to the settlement of a purchase contract.

The purchase contracts may require us to make periodic payments to the holders thereof or vice versa, which payments may be deferred to the extent set forth in the applicable prospectus supplement, and those payments may be unsecured or prefunded on some basis. The purchase contracts may require the holders thereof to secure their obligations in a specified manner to be described in the applicable prospectus supplement. Alternatively, purchase contracts may require holders to satisfy their obligations thereunder when the purchase contracts are issued. Our obligation to settle such pre-paid purchase contracts on the relevant settlement date may constitute indebtedness. Accordingly, pre-paid purchase contracts will be issued under an indenture.

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DESCRIPTION OF UNITS

As specified in the applicable prospectus supplement, we may issue units consisting of one or more purchase contracts, warrants, debt securities, common shares or any combination of such securities. The applicable supplement will describe:

· the terms of the units and of the warrants, debt securities, preferred shares and/or common shares comprising the units, including whether and under what circumstances the securities comprising the units may be traded separately;
· a description of the terms of any unit agreement governing the units; and
· a description of the provisions for the payment, settlement, transfer or exchange of the units.

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FORMS OF SECURITIES

Each debt security, warrant and unit will be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Certificated securities will be issued in definitive form and global securities will be issued in registered form. Definitive securities name you or your nominee as the owner of the security, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable. Global securities name a depositary or its nominee as the owner of the debt securities, warrants or units represented by these global securities. The depositary maintains a computerized system that will reflect each investor's beneficial ownership of the securities through an account maintained by the investor with its broker/dealer, bank, trust company or other representative, as we explain more fully below.

Registered Global Securities

We may issue registered debt securities, warrants and units in the form of one or more fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement and registered in the name of that depositary or nominee. In those cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees.

If not described below, any specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement relating to those securities. We anticipate that the following provisions will apply to all depositary arrangements.

Ownership of beneficial interests in a registered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may hold interests through participants. Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the participants' accounts with the respective principal or face amounts of the securities beneficially owned by the participants. Any dealers, underwriters or agents participating in the distribution of the securities will designate the accounts to be credited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by the depositary, with respect to interests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some states may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary, or its nominee, is the registered owner of a registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities represented by the registered global security for all purposes under the applicable indenture, warrant agreement or unit agreement. Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the applicable indenture, warrant agreement or unit agreement. Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any rights of a holder under the applicable indenture, warrant agreement or unit agreement. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the applicable indenture, warrant agreement

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or unit agreement, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Principal, premium, if any, and interest payments on debt securities, and any payments to holders with respect to warrants or units, represented by a registered global security registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of ADC Therapeutics SA, the trustees, the warrant agents, the unit agents or any other agent of ADC Therapeutics SA, agent of the trustees or agent of the warrant agents or unit agents will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests.

We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment of principal, premium, interest or other distribution of underlying securities or other property to holders on that registered global security, will immediately credit participants' accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in "street name," and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will issue securities in definitive form in exchange for the registered global security that had been held by the depositary. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or names that the depositary gives to the relevant trustee, warrant agent, unit agent or other relevant agent of ours or theirs. It is expected that the depositary's instructions will be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in the registered global security that had been held by the depositary.

38

PLAN OF DISTRIBUTION

We may sell the securities in one or more of the following ways (or in any combination) from time to time:

· through underwriters or dealers;
· directly to a limited number of purchasers or to a single purchaser;
· in "at the market offerings," within the meaning of Rule 415(a)(4) of the Securities Act, into an existing trading market on an exchange or otherwise;
· through agents; or
· through any other method permitted by applicable law and described in the applicable prospectus supplement.

The prospectus supplement will state the terms of the offering of the securities, including:

· the name or names of any underwriters, dealers or agents;
· the purchase price of such securities and the proceeds to be received by us, if any;
· any underwriting discounts or agency fees and other items constituting underwriters' or agents' compensation;
· any public offering price;
· any discounts or concessions allowed or reallowed or paid to dealers; and
· any securities exchanges on which the securities may be listed.

Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

If underwriters are used in the sale, the securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including:

· negotiated transactions;
· at a fixed public offering price or prices, which may be changed;
· at market prices prevailing at the time of sale;
· at prices related to prevailing market prices; or
· at negotiated prices.

Unless otherwise stated in a prospectus supplement, the obligations of the underwriters to purchase any securities will be conditioned on customary closing conditions and the underwriters will be obligated to purchase all of such series of securities, if any are purchased.

The securities may be sold through agents from time to time. The prospectus supplement will name any agent involved in the offer or sale of the securities and any commissions paid to them. Generally, any agent will be acting on a best efforts basis for the period of its appointment.

Sales to or through one or more underwriters or agents in at-the-market offerings will be made pursuant to the terms of a distribution agreement with the underwriters or agents. Such underwriters or agents may act on an agency basis or on a principal basis. During the term of any such agreement, shares may be

39

sold on a daily basis on any stock exchange, market or trading facility on which the common shares are traded, in privately negotiated transactions or otherwise as agreed with the underwriters or agents. The distribution agreement will provide that any common share sold will be sold at negotiated prices or at prices related to the then-prevailing market prices for our common shares. Therefore, exact figures regarding proceeds that will be raised or commissions to be paid cannot be determined at this time and will be described in a prospectus supplement. Pursuant to the terms of the distribution agreement, we may also agree to sell, and the relevant underwriters or agents may agree to solicit offers to purchase, blocks of our common shares or other securities. The terms of each such distribution agreement will be described in a prospectus supplement.

We may authorize underwriters, dealers or agents to solicit offers by certain purchasers to purchase the securities at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. The contracts will be subject only to those conditions set forth in the prospectus supplement, and the prospectus supplement will set forth any commissions paid for solicitation of these contracts.

Underwriters and agents may be entitled under agreements entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which the underwriters or agents may be required to make.

The prospectus supplement may also set forth whether or not underwriters may over-allot or effect transactions that stabilize, maintain or otherwise affect the market price of the securities at levels above those that might otherwise prevail in the open market, including, for example, by entering stabilizing bids, effecting syndicate covering transactions or imposing penalty bids.

Underwriters and agents may be customers of, engage in transactions with, or perform services for us and our affiliates in the ordinary course of business.

Each series of securities will be a new issue of securities and will have no established trading market, other than our common shares, which are listed on the NYSE. Any underwriters to whom securities are sold for public offering and sale may make a market in the securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The securities, other than our common shares, may or may not be listed on a national securities exchange.

40

LEGAL MATTERS

The validity of certain securities and certain other matters with respect to Swiss law will be passed upon for us by Homburger AG, Zurich, Switzerland. The validity of certain securities and certain matters with respect to U.S. federal and New York State law will be passed upon for us by Davis Polk & Wardwell LLP, New York, New York. Any underwriters, dealers or agents will be advised by their own legal counsel concerning issues relating to any offering.

EXPERTS

The consolidated financial statements and management's assessment of the effectiveness of internal control over ‎financial reporting (which is included in Management's Report on Internal Control over Financial Reporting) ‎incorporated in this prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, ‎‎2023 have been so incorporated in reliance on the report of PricewaterhouseCoopers SA, an independent registered ‎public accounting firm, given on the authority of said firm as experts in auditing and accounting. ‎

ENFORCEMENT OF JUDGMENTS

We are organized under the laws of Switzerland and our registered office and domicile is located in Epalinges, Switzerland. Moreover, a number of our directors and executive officers are not residents of the United States, and all or a substantial portion of the assets of such persons are located outside the United States. As a result, it may not be possible for investors to effect service of process within the United States upon us or upon such persons or to enforce against them judgments obtained in U.S. courts, including judgments in actions predicated upon the civil liability provisions of the federal securities laws of the United States. We have been advised by our Swiss counsel that there is doubt as to the enforceability in Switzerland of original actions, or in actions for enforcement of judgments of U.S. courts, of civil liabilities to the extent solely predicated upon the federal and state securities laws of the United States. Original actions against persons in Switzerland based solely upon the U.S. federal or state securities laws are governed, among other things, by the principles set forth in the Swiss Federal Act on Private International Law (the "PILA"). The PILA provides that the application of provisions of non-Swiss law by the courts in Switzerland shall be precluded if the result would be incompatible with Swiss public policy. Also, mandatory provisions of Swiss law may be applicable regardless of any other law that would otherwise apply.

Switzerland and the United States do not have a treaty providing for reciprocal recognition of and enforcement of judgments in civil and commercial matters. The recognition and enforcement of a judgment of the courts of the United States in Switzerland is governed by the principles set forth in the PILA. The PILA provides in principle that a judgment rendered by a non-Swiss court may be enforced in Switzerland only if:

· the non-Swiss court had jurisdiction pursuant to the PILA;
· the judgment of such non-Swiss court has become final and non-appealable;
· the judgment does not contravene Swiss public policy;
· the court procedures and the service of documents leading to the judgment were in accordance with the due process of law; and
· no proceeding involving the same position and the same subject matter was first brought in Switzerland, or adjudicated in Switzerland, or was earlier adjudicated in a third state and this decision is recognizable in Switzerland.

41

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational requirements of the Exchange Act. Accordingly, we are required to file reports and other information with the SEC, including annual, quarterly and current reports and proxy and information statements. The SEC maintains an internet site at sec.gov that contains reports, proxy and information statements and other information we have filed electronically with the SEC.

We have filed with the SEC a "shelf" registration statement (including amendments and exhibits to the registration statement) on Form S-3 under the Securities Act. This prospectus, which is part of the registration statement, does not contain all of the information set forth in the registration statement and the exhibits and schedules to the registration statement. We have omitted parts of the registration statement in accordance with the rules and regulations of the SEC. For more detail about us and the securities that may be offered by this prospectus, you may examine the registration statement on Form S-3 and the exhibits filed with it at the website provided in the previous paragraph.

We maintain a corporate website at adctherapeutics.com. The reference to our website is an inactive textual reference only, and information contained therein or connected thereto is not incorporated into this prospectus or the registration statement of which it forms a part.

42

INFORMATION INCORPORATED BY REFERENCE

The rules of the SEC allow us to incorporate by reference information in this prospectus, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference in this prospectus is considered to be a part of this prospectus. Any statement made in this prospectus or in a document incorporated or deemed to be incorporated by reference in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. This prospectus incorporates by reference the documents listed below:

· our Annual Report on Form 10-K for the year ended December 31, 2023;
· our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024and June 30, 2024;
· our Current Reports on Form 8-K filed with the SEC on January 4, 2024(containing Item 8.01 information), January 19, 2024, January 24, 2024, February 29, 2024, May 8, 2024and June 14, 2024; and
· our Registration Statement on Form 8-A filed with the SEC on May 11, 2020and any ‎amendment or report filed for the purpose of updating such description.‎

All subsequent documents that we file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding, in each case, any information or documents deemed to be furnished and not filed), (i) on or after the date of the initial filing of the registration statement of which this prospectus forms a part and prior to the effectiveness of such registration statement and (ii) on or after the date of this prospectus and prior to the termination or expiration of the registration statement of which this prospectus forms a part, shall be incorporated by reference.

You can obtain any of the filings incorporated by reference in this prospectus through us or from the SEC through ‎the SEC's website at sec.gov. Our filings with the SEC are also available free of charge on our website (adctherapeutics.com) as soon as reasonably practicable after they are filed with, or furnished to, the SEC. The reference to our website is an inactive textual reference only, and information contained ‎therein or connected thereto is not incorporated into this prospectus or the registration statement of which it forms a ‎part. We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, a copy of ‎any or all the reports or documents incorporated by reference in this prospectus at no cost, upon written or oral ‎request to us at the following address:‎

Investor Relations
ADC Therapeutics SA
c/o ADC Therapeutics America, Inc.
430 Mountain Avenue, 4th Floor
Murray Hill, NJ 07974
(908) 731-5556

43

ADC THERAPEUTICS SA

$300,000,000

Common Shares
Debt Securities
Warrants
Subscription Rights
Purchase Contracts
Units

PROSPECTUS

, 2024

The information in this prospectus supplement is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus supplement is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 6, 2024

PROSPECTUS SUPPLEMENT

ADC THERAPEUTICS SA

Up to $100,000,000

Common Shares

We have entered into an Open Market Sale AgreementSM with Jefferies LLC ("Jefferies" or the "sales agent"), dated August 6, 2024, relating to the sale of our common shares, par value CHF 0.08 per share, offered by this prospectus supplement and the accompanying prospectus (such agreement, the "sales agreement"). In accordance with the terms of the sales agreement, under this prospectus supplement, we may offer and sell our common shares having an aggregate offering price of up to $100,000,000 from time to time through the sales agent.

Sales of our common shares, if any, under this prospectus supplement will be made by any method permitted that is deemed an "at the market offering" as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended (the "Securities Act"). The sales agent is not required to sell any specific amount, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

The sales agent will be entitled to compensation at a commission rate of up to 3.0% of the gross sales price of any common shares sold under the sales agreement. In connection with the sale of common shares on our behalf, the sales agent will be deemed to be an "underwriter" within the meaning of the Securities Act and the compensation of the sales agent will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the sales agent with respect to certain liabilities, including civil liabilities under the Securities Act. See "Plan of Distribution" beginning on page S-19 for additional information regarding the compensation to be paid to the sales agent.

Our common shares are listed on the New York Stock Exchange ("NYSE") under the symbol "ADCT." On August 2, 2024, the last reported sale price of our common shares on the NYSE was $2.88 per share.

Investing in our securities involves a high degree of risk. See the "Risk Factors" section beginning on page S-7 of this prospectus supplement and any risk factors in our Securities and Exchange Commission ("SEC") filings that are incorporated by reference in this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Jefferies

Prospectus supplement dated , 2024.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS SUPPLEMENT S-1
PROSPECTUS SUPPLEMENT SUMMARY S-3
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS S-5
RISK FACTORS S-7
USE OF PROCEEDS S-9
DILUTION S-10
TAXATION S-11
PLAN OF DISTRIBUTION S-19
LEGAL MATTERS S-21
EXPERTS S-21
WHERE YOU CAN FIND MORE INFORMATION S-22
INFORMATION INCORPORATED BY REFERENCE S-23

ABOUT THIS PROSPECTUS SUPPLEMENT

This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part is the accompanying prospectus, which is part of a registration statement that we filed with the SEC using a "shelf" registration process. The accompanying prospectus provides you with a general description of the securities that may be offered by us, some of which may not apply to this offering. This prospectus supplement and the information incorporated by reference in this prospectus supplement supplements, updates and amends information contained or incorporated by reference in the accompanying prospectus.

Before buying any of the securities that we are offering, you should carefully read both this prospectus supplement and the accompanying prospectus with all of the information incorporated by reference in this prospectus supplement, as well as the additional information described under the heading "Where You Can Find More Information" and "Information Incorporated by Reference." These documents contain important information that you should consider when making your investment decision. We have filed or incorporated by reference exhibits to the registration statement of which this prospectus supplement forms a part. You should read the exhibits carefully for provisions that may be important to you.

To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference in this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement, provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date - for example, a document incorporated by reference in this prospectus supplement - the statement in the document having the later date modifies or supersedes the earlier statement.

The information contained in this prospectus supplement, the accompanying prospectus or any document incorporated by reference in this prospectus supplement is accurate only as of their respective dates, regardless of the time of delivery of this prospectus supplement, the accompanying prospectus or the documents incorporated by reference in this prospectus supplement or in the accompanying prospectus or the sale of any securities. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

Neither we nor the sales agent have authorized anyone to provide you with information that is different from that contained or incorporated by reference in this prospectus supplement or the accompanying prospectus or any free writing prospectus we may authorize to be delivered or made available to you. Neither we nor the sales agent take responsibility for, or provide assurance as to the reliability of, any other information that others may give you. This prospectus supplement does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful.

For investors outside the United States: Neither we nor the sales agent have taken any action that would permit the offering or possession or distribution of this prospectus supplement in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the securities described herein and the distribution of this prospectus supplement outside the United States.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus to "ADC Therapeutics," "ADCT," the "Company," "we," "our," "ours," "us" or similar terms refer to ADC Therapeutics SA and its consolidated subsidiaries.

Trademarks

We own various trademark registrations and applications, and unregistered trademarks, including ADC Therapeutics, ADCT, ZYNLONTA and our corporate logo. All other trade names, trademarks and service

S-1

marks of other companies appearing in this prospectus supplement are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus supplement may be referred to without the ® and ™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend to use or display other companies' trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

S-2

PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights the information contained elsewhere in this prospectus supplement or incorporated by reference herein. Because this is only a summary, it does not contain all of the information that may be important to you. For a more complete understanding of this offering, we encourage you to read this entire prospectus supplement and the documents incorporated by reference herein as well as the accompanying prospectus. You should read the following summary together with the more detailed information and consolidated financial statements and the notes to those statements incorporated by reference into this prospectus supplement. Some of the statements in this prospectus supplement are forward-looking statements. See "Cautionary Statement Regarding Forward-Looking Statements."

Our Company

ADC Therapeutics is a leading, commercial-stage global pioneer in the field of antibody drug conjugates ("ADCs") with a validated and differentiated technology platform with multiple payloads and targets, a robust next-generation research and development toolbox, and specialized end-to-end capabilities. We are advancing our proprietary ADC technology to transform the treatment paradigm for patients with hematologic malignancies and solid tumors.

Company and Corporate Information

We are a Swiss stock corporation (société anonyme) organized under the laws of Switzerland. We were incorporated ‎as a Swiss limited liability company (société à responsabilité limitée) on June 6, 2011 and converted into a Swiss ‎stock corporation (société anonyme) under the laws of Switzerland on October 13, 2015. We have three ‎subsidiaries: ADC Therapeutics (UK) Limited, ADC Therapeutics America, Inc. and ADC Therapeutics (NL) BV. ‎Our principal executive office is located at Biopôle, Route de la Corniche 3B, 1066 Epalinges, Switzerland and our ‎telephone number is +41 21 653 02 00. Our website is adctherapeutics.com. The reference to our website is an inactive textual reference only, and information contained therein or connected thereto is not incorporated into this prospectus supplement or the registration statement of which it forms a part.

The Offering

Common shares offered by us Common shares having an aggregate offering price of up to $100,000,000.
Common shares outstanding as of June 30, 2024 96,469,641 shares.
Plan of distribution "At the market offering" that may be made from time to time through the sales agent. See "Plan of Distribution" on page S-19 of this prospectus supplement.
Use of proceeds We intend to use the net proceeds from this offering primarily to fund research and development and commercialization activities and for working capital and other general corporate purposes. See "Use of Proceeds."
Risk factors ‎Investing in our securities involves a high degree ‎of risk. See "Risk Factors" in this prospectus supplement and in our SEC filings that are incorporated by reference in this prospectus supplement and the accompanying prospectus.

S-3

Listing Our common shares are listed on the NYSE under the symbol "ADCT."‎

In this prospectus supplement, unless otherwise indicated, the number of common shares outstanding as of June 30, 2024 excludes:

· 9,958,023 aggregate common shares issuable upon the exercise of options outstanding under our 2019 Equity Incentive Plan, Conditional Share Capital Plan and Inducement Plan (collectively, our "share-based compensation plans") as of June 30, 2024, at a weighted-average exercise price of $7.77 per share;
· 5,789,876 common shares issuable upon vesting of restricted share units outstanding under our share-based compensation plans as of June 30, 2024;
· 8,328,444 additional common shares reserved for future issuance under our share-based compensation plans as of June 30, 2024;
· 2,984,217 common shares we hold in treasury as of June 30, 2024; and
· 8,163,265 common shares issuable upon the exercise of warrants with an exercise price of CHF 0.08 per share, 527,295 common shares issuable upon the exercise of warrants with an exercise price of $8.30 per share, 2,631,578 common shares issuable upon the exercise of warrants with an exercise price of $24.70 per share and 1,781,262 common shares issuable upon the exercise of warrants with an exercise price of $28.07 per share, in each case, outstanding as of June 30, 2024.

S-4

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the documents incorporated by reference in this prospectus supplement contain statements that constitute ‎forward-looking statements within the meaning of Section 21E of the Exchange Act and Section 27A of the ‎Securities Act of 1933, as amended (the "Securities Act"). All statements other than statements of historical facts,‎ ‎including statements regarding our future catalysts, results of operations and financial position, business and commercial ‎strategy, market opportunities, products and product candidates, research pipeline, ongoing and planned ‎preclinical studies and clinical trials, regulatory submissions and approvals, research and development costs, projected revenues and expenses and ‎the timing of revenues and expenses, timing and likelihood of success, as well as plans and objectives of ‎management for future operations are forward-looking statements. Many of the forward-looking statements ‎contained in this prospectus supplement can be identified by the use of forward-looking words such as "anticipate," "believe," "could," "expect," "should," "plan," "intend," "estimate," "will" and "potential," among others.‎

Forward-looking statements are based on our management's beliefs and assumptions and on information available ‎to our management at the time such statements are made. Such statements are subject to known and unknown risks and uncertainties, ‎and actual results may differ materially from those expressed or implied in the forward-looking statements due to ‎various factors, including, but not limited to: the substantial net losses that we have incurred since our inception, our expectation to continue to incur losses for the foreseeable future and our need to raise additional capital to fund our operations and execute our business plan; our indebtedness under the loan agreement and guaranty (the "Loan Agreement") with certain affiliates and/or funds managed by each of Oaktree Capital Management, L.P. and Owl Rock Capital Advisors LLC, as lenders, and Blue Owl Opportunistic Master Fund I, L.P., as administrative agent, and the associated restrictive covenants thereunder; the purchase and sale agreement with certain entities managed by HealthCare Royalty Management, LLC and its negative effect on the amount of cash that we are able to generate from sales of, and licensing agreements involving, ZYNLONTA and on our attractiveness as an acquisition target; our ability to complete clinical trials on expected timelines, if at all; the timing, outcome and results of ongoing or planned clinical trials, whether the Company sponsored trials or through investigator initiated trials, and the sufficiency of such results; undesirable side effects or adverse events of our products and product candidates; our and our partners' ability to obtain and maintain regulatory approval for our product and product candidates; our and our partners' ability to successfully commercialize our products; the availability and scope of coverage and reimbursement for our products; the complexity and difficulty of manufacturing our products and product candidates; the substantial competition in our industry, including new technologies and therapies; the timing and results of any early research projects and future clinical outcomes; our reliance on third parties for preclinical studies and clinical trials and for the manufacture, production, storage and distribution of our products and product candidates and certain commercialization activities for our products; our ability to obtain, maintain and protect our intellectual property rights and our ability to operate our business without infringing on the intellectual property rights of others; our estimates regarding future revenue, expenses and needs for additional financing; the size and growth potential of the markets for our products and product candidates; potential product liability lawsuits and product recalls; and those identified ‎in the "Risk Factors" section of this prospectus supplement and the documents incorporated by reference in this prospectus supplement.

Because forward-looking statements are inherently subject to risks and ‎uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you ‎should not rely on these forward-looking statements as predictions of future events. Moreover, we operate in an ‎evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for ‎management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to ‎publicly update or revise any forward-looking statements, whether as a result of any new information, future ‎events, changed circumstances or otherwise. You should read this prospectus supplement, the documents incorporated by ‎reference in this prospectus supplement and the documents that we have filed as exhibits to the registration statement of which ‎the accompanying prospectus is a part completely and with the understanding that our actual future results may be materially ‎different from what we expect.‎

S-5

In addition, statements that "we believe" and similar statements reflect our beliefs and opinions on the relevant ‎subject. These statements are based upon information available to us as of the date of such statements, and while ‎we believe such information forms a reasonable basis for such statements, such information may be limited or ‎incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, ‎or review of, all potentially available relevant information. These statements are inherently uncertain and investors ‎are cautioned not to unduly rely upon these statements.‎

S-6

RISK FACTORS

Investing in our securities involves risk. Before making a decision to invest in our securities, you should carefully consider the risks described below and under "Risk Factors" in our most recent Annual Report on Form 10-K, and any updates to those risk factors in our subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K incorporated by reference in this prospectus supplement, together with all of the other information appearing or incorporated by reference in this prospectus supplement, in light of your particular investment objectives and financial circumstances. These risks and uncertainties are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently believe to be immaterial may also adversely affect our business. If any of the events or developments were to occur, our business, results of operations, financial condition and prospects could suffer materially.

Risks Related to This Offering

You may experience immediate and substantial dilution in the book value of your investment.

If you purchase our common shares in this offering, you will experience immediate dilution in an amount equal to the difference between the purchase price per share and our then-net tangible book value per common share. See "Dilution."

The issuance of common shares in connection with the exercise of securities convertible into or exercisable for our common shares would dilute your ownership interest and could materially affect the market price of our common shares and our earnings per share.

To the extent that any outstanding warrants are exercised, any outstanding options under our share-based compensation plans are exercised, any outstanding RSUs under our share-based compensation plans vest, or new options or RSUs are issued under our share-based compensation plans, substantial amounts of our common shares may be issued in the future. We cannot quantify the number of common shares that will be issued in connection with such exercise and vesting. However, the issuance of common shares pursuant to such exercise and vesting would dilute your ownership interest and could materially affect the market price of our common shares and our earnings per share.

The actual number of common shares we will sell under the sales agreement and the resulting gross proceeds is uncertain.

Subject to certain limitations in the sales agreement and compliance with applicable law, we have the discretion to deliver a placement notice to the sales agent at any time throughout the term of the sales agreement. The number of common shares that are sold by the sales agent after we deliver a placement notice will fluctuate based on the market price of our common shares during the sales period and limits we set in the placement notice. Because the price per share sold will fluctuate based on the market price of our common shares during the sales period, it is not possible to predict the number of common shares that will be ultimately sold or the resulting gross proceeds.

The common shares offered in this offering will be sold in "at the market offerings." Investors who purchase our common shares in this offering at different times will likely pay different prices.

Investors who purchase our common shares in this offering at different times will likely pay different prices, and so may experience different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices and numbers of common shares sold, and subject to certain limitations in the sales agreement, there is no minimum or maximum sales price. Investors may experience a decline in the value of their common shares and dilution as a result of sales made at prices lower than the prices they paid.

We have broad discretion in the use of the net proceeds from this offering, and we may not use them effectively.

S-7

We currently intend to use the net proceeds from this offering as described in "Use of Proceeds." However, our board of directors and our management retains broad discretion in the application of the net proceeds from this offering and could spend the proceeds in ways that do not improve our results of operations or enhance the value of our common shares. Our failure to apply these funds effectively could result in financial losses, which could have a material adverse effect on our business, results of operations, financial condition and prospects.

S-8

USE OF PROCEEDS

We may offer and sell our common shares having an aggregate offering price of up to $100,000,000 from time to time through the sales agent. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time.

We intend to use the net proceeds from this offering, if any, primarily to fund research and development and commercialization activities and for working capital and other general corporate purposes.

Our expected use of the net proceeds from this offering represents our current intentions based on our present plans and business condition, which could change as our plans and business conditions evolve. The amounts and timing of our actual use of the net proceeds from this offering will vary depending on numerous factors. As a result, we cannot predict with certainty all of the particular uses for any net proceeds to be received or the amounts that we will actually spend on the uses set forth above. Our board of directors and our management retains broad discretion in the application of the net proceeds from this offering.

Pending the use of the proceeds from this offering, we intend to invest the net proceeds in a variety of capital preservation instruments, which may include all or a combination of short-term and long-term interest-bearing instruments, investment-grade securities, and direct or guaranteed obligations of the U.S. government. We cannot predict whether the proceeds invested will yield a favorable return.

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DILUTION

Net tangible book value per common share is determined by dividing our total assets, less intangible assets, less total liabilities by the number of our common shares outstanding.

Our historical net tangible book value as of June 30, 2024 was -$141.4 million, or -$1.47 per common share. After giving effect to the assumed sale by us of $100,000,000 of common shares at an assumed public offering price of $2.88 per share, which was the last reported sale price of our common shares on the NYSE on August 2, 2024, and after deducting commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of June 30, 2024 would have been -$46.5 million, or - $0.35 per common share, representing an immediate increase of $1.12 per common share and immediate dilution of $3.23 per common share.

To the extent that any outstanding warrants are exercised, any outstanding options under our share-based compensation plans are exercised, any outstanding RSUs under our share-based compensation plans vest, new options or RSUs are issued under our share-based compensation plans or we issue additional common shares in the future, there will be further dilution to investors participating in this offering.

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TAXATION

The following discussion is based on the tax laws, regulations and regulatory practices of Switzerland and the United States as in effect on the date hereof, which are subject to change (or subject to changes in interpretation), possibly with retroactive effect.

Current and prospective shareholders are advised to consult their own tax advisers in light of their particular circumstances as to the Swiss or U.S. tax laws, regulations and regulatory practices that could be relevant for them in connection with owning and selling or otherwise disposing of our common shares and receiving dividends and similar cash or in-kind distributions on our common shares (including dividends on liquidation proceeds and share dividends) or distributions on our common shares based upon a capital reduction or reserves paid out of capital contributions and the consequences thereof under the tax laws, regulations and regulatory practices of Switzerland or the United States.

Swiss Tax Considerations

Withholding Tax

Under present Swiss tax law, dividends due and similar cash or in-kind distributions made by the Company to a shareholder of common shares (including liquidation proceeds and bonus shares) are subject to Swiss federal withholding tax ("Withholding Tax"), currently at a rate of 35% (applicable to the gross amount of taxable distribution). However, the repayment of the par value of the common shares and any repayment of qualifying additional paid-in capital (capital contribution reserves), within the limitations accepted by the legislation in force when such dividend becomes due and the respective administrative practice, are not subject to the Withholding Tax. The Company is obliged to deduct any applicable Withholding Tax from the gross amount of any taxable distribution and to pay the tax to the Swiss Federal Tax Administration within 30 days of the due date of such distribution.

Swiss resident individuals who hold their common shares as private assets ("Resident Private Shareholders") are in principle eligible for a full refund or credit against income tax of the Withholding Tax if they duly report the underlying income in their income tax return. In addition, (i) corporate and individual shareholders who are resident in Switzerland for tax purposes, (ii) corporate and individual shareholders who are not resident in Switzerland, and who, in each case, hold their common shares as part of a trade or business carried on in Switzerland through a permanent establishment with fixed place of business situated in Switzerland for tax purposes and (iii) Swiss resident private individuals who, for income tax purposes, are classified as "professional securities dealers" for reasons of, inter alia, frequent dealing, or leveraged investments, in shares and other securities (collectively, "Domestic Commercial Shareholders") are in principle eligible for a full refund or credit against income tax of the Withholding Tax if they duly report the underlying income in their statements of operations or income tax return, as the case may be.

Shareholders who are not resident in Switzerland for tax purposes, and who, in each case and during the respective taxation year, do not hold their common shares as part of a trade or business carried on through a permanent establishment with fixed place of business situated in Switzerland for tax purposes, and who are not subject to corporate or individual income taxation in Switzerland for any other reason (collectively, "Non-Resident Shareholders") may be entitled to a total or partial refund of the Withholding Tax if the country in which such recipient resides for tax purposes maintains a bilateral treaty for the avoidance of double taxation with Switzerland and further conditions of such treaty are met. Non-Resident Shareholders should be aware that the procedures for claiming treaty benefits (and the time required for obtaining a refund) may differ from country to country. Non-Resident Shareholders should consult their own legal, financial or tax advisors regarding receipt, ownership, purchases, sale or other dispositions of common shares and the procedures for claiming a refund of the Withholding Tax.

Swiss Issuance Stamp Duty

The Company will be subject to the Swiss issuance stamp duty (droit de timbre d'émission) on the issuance of common shares of 1% of the offering price, net of certain deductions.

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Swiss Securities Transfer Stamp Duty

Any transactions in common shares in the secondary markets are subject to Swiss securities transfer stamp duty at an aggregate rate of 0.15% of the consideration paid for such common shares; however, only if a bank or other securities dealer in Switzerland, as defined in the Swiss Federal Stamp Tax Act (loi fédérale sur les droits de timbre), is a party or an intermediary to the transaction and no exemption applies.

Swiss Federal, Cantonal and Communal Individual Income Tax and Corporate Income Tax

Non-Resident Shareholders

Non-Resident Shareholders are not subject to any Swiss federal, cantonal or communal income tax on dividend payments and similar distributions because of the mere holding of common shares. The same applies for capital gains on the sale of common shares subject to certain exceptions. For Withholding Tax consequences, see "-Swiss Tax Considerations-Withholding Tax."

Resident Private Shareholders and Domestic Commercial Shareholders

Resident Private Shareholders who receive dividends and similar cash or in-kind distributions (including liquidation proceeds as well as bonus shares or taxable repurchases of common shares as described above), which are not repayments of the par value of common shares or, within the limitations accepted by the legislation in force and the respective administrative practice, qualifying additional paid-in capital (capital contribution reserves), are required to report such receipts in their individual income tax returns and are subject to Swiss federal, cantonal and communal income tax on any net taxable income for the relevant tax period. A gain or a loss by Resident Private Shareholders realized upon the sale or other disposition of common shares to a third party will generally be a tax-free private capital gain or a non-tax-deductible capital loss, as the case may be. Under exceptional circumstances, the capital gain may be re-characterized into a taxable dividend, in particular upon taxable repurchase of common shares as described above. When a capital gain is re-characterized as a dividend, the relevant income for tax purposes corresponds to the difference between the repurchase price and the sum of the par value of common shares and, within the limitations accepted by the legislation in force and the respective administrative practice, qualifying additional paid-in capital (capital contribution reserves).

Domestic Commercial Shareholders who receive dividends and similar cash or in-kind distributions (including liquidation proceeds as well as bonus shares) are required to recognize such payments in their statements of operations for the relevant tax period and are subject to Swiss federal, cantonal and communal individual or corporate income tax, as the case may be, on any net taxable earnings accumulated (including the dividends) for such period. Domestic Commercial Shareholders who are corporate taxpayers may qualify for participation relief on dividend distributions (réduction pour participations), if common shares held have an aggregate market value of at least CHF 1 million. For cantonal and communal income tax purposes, the regulations on participation relief are broadly similar, depending on the canton of residency.

Domestic Commercial Shareholders are required to recognize a gain or loss realized upon the disposal of common shares in their statement of operations for the respective taxation period and are subject to Swiss federal, cantonal and communal individual or corporate income tax, as the case may be, on any net taxable earnings (including the gain or loss realized on the sale or other disposition of common shares) for such taxation period.

Swiss Wealth Tax and Capital Tax

Non-Resident Shareholders

Non-Resident Shareholders holding common shares are not subject to cantonal and communal wealth or annual capital tax because of the mere holding of common shares.

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Resident Private Shareholders

Resident Private Shareholders are required to report their common shares as part of their private wealth and are subject to cantonal and communal wealth tax.

Domestic Commercial Shareholders

Domestic Commercial Shareholders are required to report their common shares as part of their business wealth or taxable capital, as defined, and are subject to cantonal and communal wealth or annual capital tax.

Automatic Exchange of Information in Tax Matters

On November 19, 2014, Switzerland signed the Multilateral Competent Authority Agreement. The Multilateral Competent Authority Agreement is based on Article 6 of the OECD/Council of Europe administrative assistance convention and is intended to ensure the uniform implementation of Automatic Exchange of Information (the "AEOI"). The Federal Act on the International Automatic Exchange of Information in Tax Matters (the "AEOI Act") entered into force on January 1, 2017. The AEOI Act is the legal basis for the implementation of the AEOI standard in Switzerland.

The AEOI is being introduced in Switzerland through bilateral agreements or multilateral agreements. The agreements have been, and will be, concluded on the basis of guaranteed reciprocity, compliance with the principle of speciality (i.e., the information exchanged may only be used to assess and levy taxes (and for criminal tax proceedings)) and adequate data protection.

Based on such multilateral or bilateral agreements and the implementation of Swiss law, Switzerland collects and exchanges data in respect of financial assets, including common shares, held in, and income derived thereon and credited to, accounts or deposits with a paying agent in Switzerland for the benefit of individuals resident in a European Union member state or in a treaty state.

Swiss Facilitation of the Implementation of the U.S. Foreign Account Tax Compliance Act

Switzerland has concluded an intergovernmental agreement with the United States to facilitate the implementation of U.S. Foreign Account Tax Compliance Act. The agreement ensures that the accounts held by U.S. persons with Swiss financial institutions are disclosed to the U.S. tax authorities either with the consent of the account holder or by means of group requests within the scope of administrative assistance. Information will not be transferred automatically in the absence of consent, and instead will be exchanged only within the scope of administrative assistance on the basis of the double taxation agreement between the United States and Switzerland. On June 27, 2024, Switzerland and the United States signed a new FATCA agreement. The new agreement provides for a different model for the exchange of financial account data. If the agreement is implemented, the current direct-notification-based regime shall be replaced by a regime where the relevant information is sent to the Swiss Federal Tax Administration, which in turn provides the information to the U.S. tax authorities. The exchange of information shall also be mutual and automatic. Implementation of the new FATCA agreement requires national law to be amended. According to the current schedule, Switzerland's change of model should come into force on January 1, 2027.

Material U.S. Federal Income Tax Consequences for U.S. Holders

The following is a description of the material U.S. federal income tax consequences to the U.S. Holders, as defined below, of owning and disposing of our common shares. It does not describe all tax considerations that may be relevant to a particular person's decision to acquire common shares.

This discussion applies only to a U.S. Holder that holds common shares as capital assets for U.S. federal income tax purposes (generally, property held for investment). In addition, it does not describe any tax consequences other than U.S. federal income tax consequences, including state and local tax consequences and estate tax consequences, and does not describe all of the U.S. federal income tax

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consequences that may be relevant in light of the U.S. Holder's particular circumstances, including alternative minimum tax consequences, the potential application of the provisions of the Internal Revenue Code of 1986, as amended (the "Code") known as the Medicare contribution tax and tax consequences applicable to U.S. Holders subject to special rules, such as:

certain banks, insurance companies and other financial institutions;
brokers, dealers or traders in securities who use a mark-to-market method of tax accounting;
persons holding common shares as part of a straddle, wash sale, conversion transaction or other integrated transaction or persons entering into a constructive sale with respect to the common shares;
persons whose functional currency for U.S. federal income tax purposes is not the U.S. dollar;
entities or arrangements classified as partnerships or S corporations for U.S. federal income tax purposes;
tax-exempt entities, including an "individual retirement account" or "Roth IRAs" and governmental entities;
real estate investment trusts or regulated investment companies;
former U.S. citizens or long-term residents of the United States;
persons subject to Section 451(b) of the Code;
persons that own or are deemed to own 10% or more of the voting power or value of our common shares; or
persons holding common shares in connection with a trade or business conducted outside of the United States or in connection with a permanent establishment or other fixed place of business outside of the United States.

If an entity or arrangement that is classified as a partnership for U.S. federal income tax purposes holds common shares, the U.S. federal income tax treatment of a partner will generally depend on the status of the partner and the activities of the partnership. Partnerships holding common shares and partners in such partnerships should consult their tax advisers as to the particular U.S. federal income tax consequences of owning and disposing of the common shares.

This discussion is based on the Code, administrative pronouncements, judicial decisions, final, temporary and proposed Treasury regulations, and the income tax treaty between Switzerland and the United States (the "Treaty"), all as of the date hereof, any of which is subject to change or differing interpretations, possibly with retroactive effect.

A "U.S. Holder" is a beneficial owner of our common shares who, for U.S. federal income tax purposes, is eligible for the benefits of the Treaty and who is:

a citizen or individual resident of the United States;
a corporation, or other entity taxable as a corporation, created or organized in or under the laws of the United States, any state therein or the District of Columbia; or
an estate or trust, the income of which is subject to U.S. federal income taxation regardless of its source.

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U.S. Holders should consult their tax advisers concerning the U.S. federal, state, local and non-U.S. tax consequences of owning and disposing of common shares in their particular circumstances.

Passive Foreign Investment Company Rules

Under the Code, we will be a PFIC for any taxable year in which, after the application of certain look-through rules with respect to subsidiaries, either (i) 75% or more of our gross income consists of "passive income" or (ii) 50% or more of the average quarterly value of our assets consists of assets that produce, or are held for the production of, "passive income." For purposes of the above calculations, we will be treated as if we hold our proportionate share of the assets of, and receive directly our proportionate share of the income of, any other corporation in which we directly or indirectly own at least 25%, by value, of the shares of such corporation. Passive income generally includes interest, dividends, certain non-active rents and royalties, and capital gains.

Cash is generally characterized as a passive asset for these purposes. Goodwill is generally characterized as a non-passive or passive asset based on the nature of the income produced in the activity to which the goodwill is attributable. The extent to which our goodwill should be characterized as a non-passive asset is not entirely clear. We hold a substantial amount of cash, and while this continues to be the case our PFIC status for any taxable year depends largely on the value of our goodwill and the characterization of our goodwill as passive or non-passive. The value of our goodwill for any taxable year may be determined in large part by reference to the average of our market capitalization for that year. Because our market capitalization declined substantially during 2023, we believe we were a PFIC for our 2023 taxable year. There is also a risk that we will be a PFIC for 2024 and possibly future taxable years. We have not obtained any valuation of our assets (including goodwill). U.S. Holders of our common shares should consult their tax advisers regarding the value and characterization of our assets for purposes of the PFIC rules, as they are subject to some uncertainties. In addition, our PFIC status is a factual annual determination that can be made only after the end of the relevant taxable year and will depend on the composition of our income and assets and the value of our assets from time to time. Accordingly, our PFIC status for 2024 and any future taxable year is uncertain.

If we are a PFIC for any year during which a U.S. Holder holds common shares, we will continue to be treated as a PFIC with respect to that U.S. Holder for all succeeding years during which the U.S. Holder holds common shares, even if we cease to meet the threshold requirements for PFIC status, unless the U.S. Holder elects to recognize gain, if any, as if it sold its common shares as of the last day of the last tax year in which we are a PFIC (such election, a "Purging Election"). In addition, the Company may, directly or indirectly, have held or hold equity interests in other PFICs (collectively, "Lower-tier PFICs"). Under attribution rules, if the Company is a PFIC, U.S. Holders will be deemed to own their proportionate shares of the stock of Lower-tier PFICs and will be subject to U.S. federal income tax according to the rules described in the following paragraphs on (i) certain distributions by a Lower-tier PFIC and (ii) a disposition of shares of a Lower-tier PFIC, in each case as if the U.S. Holder held such shares directly, even though holders have not received the proceeds of those distributions or dispositions directly. U.S. Holders should consult their tax advisers about the consequences to them if we own one or more Lower-tier PFICs.

If we are a PFIC for any taxable year during which a U.S. Holder holds common shares, such holder will generally be subject to adverse tax consequences. Unless a U.S. Holder makes a timely "mark-to-market" election or "qualified electing fund" ("QEF") election (each discussed below), gain recognized by the U.S. Holder on sale or other disposition (including certain pledges) of common shares (including any gain recognized as a consequence of a Purging Election) will be allocated ratably over the U.S. Holder's holding period for the common shares. The amounts allocated to the taxable year of the sale or other disposition and to any year before we became a PFIC will be taxed as ordinary income. The amount allocated to each other taxable year will be subject to tax at the highest rate in effect for individuals or corporations, as appropriate, for that taxable year, and an interest charge will be imposed on the resulting tax liability. Further, to the extent that any distribution received by a U.S. Holder on its common shares exceeds 125% of the average of the annual distributions on the common shares received during the preceding three years or the U.S. Holder's holding period, whichever is shorter, that distribution will be subject to taxation in the same manner as gain, described immediately above.

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If we are a PFIC and if our common shares are "regularly traded" on a "qualified exchange," a U.S. Holder will be eligible to make a mark-to-market election with respect to our common shares that will result in tax treatment different from the general tax treatment for PFICs described above. Our common shares will be treated as "regularly traded" if more than a de minimis amount of our common shares are traded on a qualified exchange on at least 15 days during each calendar quarter. The NYSE, on which our common shares are listed, is a qualified exchange for this purpose. Once made, the election cannot be revoked without the consent of the IRS unless the shares cease to be traded on an established market.

If a U.S. Holder makes the mark-to-market election with respect to our common shares, such holder will generally recognize as ordinary income any excess of the fair market value of such holder's common shares at the end of each taxable year over their adjusted tax basis, and will recognize an ordinary loss in respect of any excess of the adjusted tax basis of the common shares over their fair market value at the end of the taxable year (but only to the extent of the net amount of income previously included as a result of the mark-to-market election). If a U.S. Holder makes the election, such holder's tax basis in their common shares will be adjusted to reflect these income or loss amounts. Any gain recognized on the sale or other disposition of common shares in a year when we are a PFIC will be treated as ordinary income and any loss will be treated as an ordinary loss (but only to the extent of the net amount of income previously included as a result of the mark-to-market election). This election will not apply to any of our non-U.S. subsidiaries. Accordingly, a U.S. Holder may continue to be subject to tax under the PFIC excess distribution regime with respect to any Lower-tier PFICs notwithstanding a mark-to-market election for the common shares.

If a company that is a PFIC provides certain information to U.S. Holders, a U.S. Holder can then avoid certain adverse tax consequences described above by making a QEF election to be taxed currently on its proportionate share of the PFIC's ordinary income and net capital gains.

The QEF election is made on a shareholder-by-shareholder basis and, once made, can be revoked only with the consent of the IRS. A U.S. Holder generally makes a QEF election by attaching a completed IRS Form 8621, including the information provided in a PFIC Annual Information Statement, to a timely filed U.S. federal income tax return for the taxable year to which the election relates. U.S. Holders should consult their tax advisers regarding the availability and tax consequences of a retroactive QEF election under their particular circumstances. In order to comply with the requirements to make a QEF election, a U.S. Holder must receive a PFIC Annual Information Statement from us. Because we believe we were a PFIC for the 2023 taxable year, we have provided information necessary for our U.S. investors to make a QEF election with respect to us for the 2023 taxable year on our website.

In addition, if we are a PFIC (or, with respect to a particular U.S. Holder, are treated as a PFIC) for a taxable year in which we pay a dividend or for the prior taxable year, the preferential dividend rates discussed below with respect to dividends paid to certain non-corporate U.S. Holders will not apply.

The rules dealing with PFICs and with the mark-to-market and QEF elections are complex and are affected by various factors in addition to those described above. Accordingly, U.S. Holders should consult their tax advisers concerning the application of the PFIC rules to our common shares under their particular circumstances.

Information Returns

If we are a PFIC for any taxable year during which a U.S. Holder holds common shares, the U.S. Holder will generally be required to file an annual report on IRS Form 8621, containing such information as the U.S. Treasury may require, with their annual U.S. federal income tax returns. A U.S. Holder's failure to file the annual report will cause the statute of limitations for such U.S. Holder's U.S. federal income tax return to remain open with respect to the items required to be included in such report until three years after the U.S. Holder files the annual report and, unless such failure is due to reasonable cause and not willful neglect, the statute of limitations for the U.S. Holder's entire U.S. federal income tax return will remain open during such period.

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Prospective U.S. holders should consult their tax advisers regarding the potential PFIC rules to an investment in common shares.

Taxation of Distributions

The following is subject to the discussion regarding the PFIC rules described above.

Distributions paid on common shares, other than certain pro rata distributions of common shares, will generally be treated as dividends to the extent paid out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Dividends paid to certain non-corporate U.S. Holders may be eligible for taxation as "qualified dividend income" and therefore, subject to applicable limitations, may be taxable at rates not in excess of the long-term capital gain rate applicable to such U.S. Holder. However, the qualified dividend income treatment will not apply if we are treated as a PFIC with respect to the U.S. Holder or if we are a PFIC for the taxable year in which the dividend is paid or the preceding taxable year.

The amount of a dividend will include any amounts withheld by us in respect of Swiss income taxes. The amount of the dividend will be treated as foreign-source dividend income to U.S. Holders and will not be eligible for the dividends-received deduction generally available to U.S. corporations under the Code. Dividends will be included in a U.S. Holder's income on the date of the U.S. Holder's receipt of the dividend. The amount of any dividend income paid in Swiss francs will be the U.S. dollar amount calculated by reference to the exchange rate in effect on the date of actual or constructive receipt, regardless of whether the payment is in fact converted into U.S. dollars at that time. If the dividend is converted into U.S. dollars on the date of receipt, a U.S. Holder should not be required to recognize foreign currency gain or loss in respect of the dividend income. A U.S. Holder may have foreign currency gain or loss if the dividend is converted into U.S. dollars after the date of receipt.

Subject to generally applicable limitations and conditions, some of which vary depending upon the U.S. Holder's particular circumstances, Swiss income taxes withheld from dividends on common shares (at a rate not exceeding the rate provided by the Treaty, in the case of a U.S. Holder eligible for a reduced rate under the Treaty) will be creditable against the U.S. Holder's U.S. federal income tax liability. These generally applicable limitations and conditions include new requirements adopted by the IRS in regulations promulgated in December 2021 (the "Foreign Tax Credit Regulations") and any Swiss tax will need to satisfy these requirements in order to be eligible to be a creditable tax to a U.S. Holder. However, the IRS released guidance in the form of a notice which provides temporary relief from the requirements of these new regulations for taxable years ending before the date that a notice or other guidance withdrawing or modifying the temporary relief is issued (or any later date specified in such notice or other guidance). In the case of a U.S. Holder that either (i) is eligible for, and properly elects, the benefits of the Treaty, or (ii) consistently elects to apply a modified version of these rules under the recently issued temporary guidance and complies with specific requirements set forth in such guidance, the Swiss tax on interest generally will be treated as a creditable tax (for taxable years for which such temporary relief applies, in the case of U.S. Holders relying on the temporary relief). In the case of all other U.S. Holders, the application of these requirements to the Swiss tax is uncertain and we have not determined whether these requirements have been met. If the Swiss tax is not a creditable tax for a U.S. Holder or such holder does not elect to claim a foreign tax credit for any foreign income taxes paid or accrued in the same taxable year, such U.S. Holder may be eligible to deduct the Swiss tax in computing its taxable income for U.S. federal income tax purposes, subject to generally applicable limitations under U.S. law. An election to deduct foreign taxes instead of claiming foreign tax credits applies to all foreign taxes paid or accrued in the taxable year. Dividend distributions will constitute income from sources without the United States and, for U.S. Holders that elect to claim foreign tax credits, generally will constitute "passive category income" for foreign tax credit purposes.

The availability and calculation of foreign tax credits and deductions for foreign taxes depend on a U.S. Holder's particular circumstances and involve the application of complex rules to those circumstances. The temporary guidance discussed above also indicates that the U.S. Treasury and the IRS are considering proposing amendments to the December 2021 regulations and that the temporary guidance can be relied upon until additional guidance is issued that withdraws or modifies the temporary guidance.

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U.S. Holders should consult their tax advisers regarding the application of these rules to their particular circumstances.

Sale or Other Disposition of Common Shares

The following is subject to the discussion regarding the PFIC rules described above.

Gain or loss realized by a U.S. Holder on the sale or other disposition of common shares will be capital gain or loss, and will be long-term capital gain or loss if the U.S. Holder's holding period for such common shares was more than one year as of the date of the sale or other disposition. The amount of the gain or loss will equal the difference between the U.S. Holder's tax basis in the common shares disposed of and the amount realized on the disposition, in each case as determined in U.S. dollars. Long-term capital gain recognized by a non-corporate U.S. Holder is subject to U.S. federal income tax at rates lower than the rates applicable to ordinary income and short-term capital gains, while short-term capital gains are subject to U.S. federal income tax at the rates applicable to ordinary income. This gain or loss will generally be U.S.-source gain or loss for foreign tax credit purposes. However, U.S. Holders that are eligible for benefits under the Treaty may be able to elect to treat the gain as foreign-source income under the Treaty and claim a foreign tax credit in respect of Swiss taxes on disposition gains. The Foreign Tax Credit Regulations generally preclude a U.S. Holder from claiming a foreign tax credit with respect to Swiss income taxes on gains from dispositions of common shares if the U.S. Holder does not elect to apply the benefits of the Treaty. However, in that case, it is possible that any Swiss taxes on disposition gains may either be deductible or reduce the amount realized on the disposition. The rules governing foreign tax credits and deductibility of foreign taxes are complex. U.S. Holders should consult their tax advisers regarding their eligibility for benefits under the Treaty and the consequences of the imposition of any Swiss tax on disposition gains. The deductibility of capital losses is subject to various limitations.

Information Reporting and Backup Withholding

Payments of dividends on our common shares and sales proceeds that are made within the United States or through certain U.S.-related financial intermediaries generally are subject to information reporting, and may be subject to backup withholding, unless (i) the U.S. Holder is a corporation or other exempt recipient or (ii) in the case of backup withholding, the U.S. Holder provides a correct taxpayer identification number and certifies that it is not subject to backup withholding.

The amount of any backup withholding from a payment to a U.S. Holder will be allowed as a credit against the U.S. Holder's U.S. federal income tax liability and may entitle it to a refund, provided that the required information is timely furnished to the IRS.

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PLAN OF DISTRIBUTION

We have entered into a sales agreement with Jefferies, under which we may offer and sell up to $100,000,000 of our common shares from time to time through Jefferies, acting as agent. Sales of our common shares, if any, under this prospectus supplement and the accompanying prospectus will be made by any method that is deemed to be an "at the market offering" as defined in Rule 415(a)(4) under the Securities Act.

Each time we wish to issue and sell common shares under the sales agreement, we will notify Jefferies of the number of common shares to be sold, the dates on which such sales are anticipated to be made, any limitation on the number of common shares to be sold in any one day and any minimum price below which sales may not be made. Once we have so instructed Jefferies, unless Jefferies declines to accept the terms of such notice, Jefferies has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such common shares up to the amount specified on such terms. The obligations of Jefferies under the sales agreement to sell our common shares are subject to a number of conditions that we must meet.

The settlement of sales of our common shares between us and Jefferies is generally anticipated to occur on the first trading day following the date on which the sale was made. Sales of our common shares as contemplated in this prospectus supplement will be settled through the facilities of The Depository Trust Company or by such other means as we and Jefferies may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

We will pay Jefferies a commission up to 3.0% of the aggregate gross proceeds we receive from each sale of our common shares. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. Except as we and Jefferies otherwise agree, we will reimburse Jefferies for the fees and disbursements of its counsel, payable upon execution of the sales agreement, in an amount not to exceed $100,000, in addition to certain ongoing disbursements of its legal counsel. We estimate that the total expenses for the offering, excluding any commissions payable to Jefferies under the terms of the sales agreement, will be approximately $2.6 million. The remaining proceeds, after deducting any other transaction fees, will equal our net proceeds from the sale of our common shares in this offering.

Jefferies will provide written confirmation to us by 5:30 pm New York City time on the day on which common shares are sold under the sales agreement. Each confirmation will include the number of common shares sold on that day, the aggregate gross proceeds of such sales and the proceeds to us.

In connection with the sale of common shares on our behalf, Jefferies will be deemed to be an "underwriter" within the meaning of the Securities Act, and the compensation of Jefferies will be deemed to be underwriting commissions or discounts. We have agreed to indemnify Jefferies against certain liabilities, including civil liabilities under the Securities Act. We have also agreed to contribute to payments Jefferies may be required to make in respect of such liabilities.

The offering of our common shares pursuant to the sales agreement will terminate as permitted therein.

This summary of the material provisions of the sales agreement does not purport to be a complete statement of its terms and conditions. A copy of the sales agreement is filed as an exhibit to the registration statement of which this prospectus supplement forms a part.

Jefferies and its affiliates may in the future provide various investment banking, commercial banking, financial advisory and other financial services for us and our affiliates, for which services they may in the future receive customary fees. In the course of its business, Jefferies may actively trade our securities for its own account or for the accounts of customers, and, accordingly, Jefferies may at any time hold long or short positions in such securities.

S-19

A prospectus supplement and the accompanying prospectus in electronic format may be made available on a website maintained by Jefferies, and Jefferies may distribute the prospectus supplement and the accompanying prospectus electronically.

S-20

LEGAL MATTERS

The validity of the common shares offered and certain other matters with respect to Swiss law will be passed upon for us by Homburger AG, Zurich, Switzerland. Certain matters with respect to U.S. federal and New York State law will be passed upon for us by Davis Polk & Wardwell LLP, New York, New York. Jefferies LLC is represented in connection with this offering by Cooley LLP, New York, New York with respect to matters of U.S. federal law and by Lenz & Staehelin, Geneva, Switzerland, with respect to matters of Swiss law.

EXPERTS

The consolidated financial statements and management's assessment of the effectiveness of internal control over ‎financial reporting (which is included in Management's Report on Internal Control over Financial Reporting) ‎incorporated in this prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, ‎‎2023 have been so incorporated in reliance on the report of PricewaterhouseCoopers SA, an independent registered ‎public accounting firm, given on the authority of said firm as experts in auditing and accounting. ‎

S-21

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational requirements of the Exchange Act. Accordingly, we are required to file reports and other information with the SEC, including annual, quarterly and current reports and proxy and information statements. The SEC maintains an internet site at sec.gov that contains reports, proxy and information statements and other information we have filed electronically with the SEC.

We have filed with the SEC a "shelf" registration statement (including amendments and exhibits to the registration statement) on Form S-3 under the Securities Act. This prospectus supplement, which is part of the registration statement, does not contain all of the information set forth in the registration statement and the exhibits and schedules to the registration statement. We have omitted parts of the registration statement in accordance with the rules and regulations of the SEC. For more detail about us and the common shares offered by this prospectus supplement, you may examine the registration statement on Form S-3 and the exhibits filed with it at the website provided in the previous paragraph.

We maintain a corporate website at adctherapeutics.com. The reference to our website is an inactive textual ‎reference only, and information contained therein or connected thereto is not incorporated into this prospectus supplement or ‎the registration statement of which it forms a part.

S-22

INFORMATION INCORPORATED BY REFERENCE

The rules of the SEC allow us to incorporate by reference information in this prospectus, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference in this prospectus supplement is considered to be a part of this prospectus supplement. Any statement made in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference in this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement. This prospectus supplement incorporates by reference the documents listed below:

· our Annual Report on Form 10-K for the year ended December 31, 2023;
· our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024and June 30, 2024;
· our Current Reports on Form 8-K filed with the SEC on January 4, 2024(containing Item 8.01 information), January 19, 2024, January 24, 2024, February 29, 2024, May 8, 2024and June 14, 2024; and
· our Registration Statement on Form 8-A filed with the SEC on May 11, 2020and any ‎amendment or report filed for the purpose of updating such description.‎

All subsequent documents that we file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding, in each case, any information or documents deemed to be furnished and not filed), (i) on or after the date of the initial filing of the registration statement of which this prospectus supplement forms a part and prior to the effectiveness of such registration statement and (ii) on or after the date of this prospectus supplement and prior to the completion or termination of this offering, shall be incorporated by reference.

You can obtain any of the filings incorporated by reference in this prospectus supplement through us or from the SEC through ‎the SEC's website at sec.gov. Our filings with the SEC are also available free of charge on our website (adctherapeutics.com) as soon as reasonably practicable after they are filed with, or furnished to, the SEC. The reference to our website is an inactive textual reference only, and information contained ‎therein or connected thereto is not incorporated into this prospectus supplement or the registration statement of which it forms a ‎part. We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, a copy of ‎any or all the reports or documents incorporated by reference in this prospectus supplement at no cost, upon written or oral ‎request to us at the following address:‎

Investor Relations
ADC Therapeutics SA
c/o ADC Therapeutics America, Inc.
430 Mountain Avenue, 4th Floor
Murray Hill, NJ 07974
(908) 731-5556

S-23

ADC THERAPEUTICS SA

Up to $100,000,000

Common Shares

PROSPECTUS SUPPLEMENT

Jefferies

, 2024

PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The following table sets forth the expenses (other than underwriting discounts and commissions or agency fees and other items constituting underwriters' or agents' compensation, if any) expected to be incurred by us in connection with a possible offering of securities registered under this registration statement:

Expenses Amount
SEC registration fee $ 15,604.03
Transfer agent's and trustee's fees and expenses (1 )
Printing expenses (1 )
Legal fees and expenses (1 )
Accounting fees and expenses (1 )
Miscellaneous costs (1 )
Total $ (1 )
(1) These fees and expenses depend on the securities offered and the number of offerings, and accordingly cannot be estimated at this time and will be reflected in the applicable prospectus supplement.

Item 15. Indemnification of Directors and Officers

Under Swiss law, a corporation may indemnify its directors or officers against losses and expenses (except for such losses and expenses arising from willful misconduct or negligence, although legal scholars advocate that at least gross negligence be required), including attorney's fees, judgments, fines and settlement amounts actually and reasonably incurred in a civil or criminal action, suit or proceeding by reason of having been the representative of, or serving at the request of, the corporation.

Subject to Swiss law, our articles of association provide for indemnification of the existing and former members of our board of directors and our executive committee as well as their heirs, executors and administrators, against liabilities arising in connection with the performance of their duties in such capacity, and our articles of association require us to advance the expenses of defending any action, suit or proceeding to existing and former members of our board of directors and our executive committee to the extent not included in insurance coverage or advanced by third parties.

In addition, under general principles of Swiss employment law, an employer may be required to indemnify an employee against losses and expenses incurred by such employee in the proper execution of their duties under the employment agreement with the company.

We have entered into indemnification agreements with each of the members of our board of directors and executive officers.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended (the "Securities Act") may be permitted to directors, officers and controlling persons of the Company, the Company has been advised that, in the opinion of the U.S. Securities and Exchange Commission (the "SEC"), such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

Item 16. Exhibits

The following documents are filed as part of this registration statement:

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Incorporation by Reference
Exhibit No. Description Form File No. Exhibit
No.
Filing Date
1.1* Form of Underwriting Agreement
1.2 Open Market Sale AgreementSM, dated August 6, 2024, between ADC Therapeutics SA and Jefferies LLC
4.1 Articles of Association of ADC Therapeutics SA 8-K 001-39071 3.1 June 14, 2024
4.1.1 Letter Agreement, dated January 18, 2024, between ADC Therapeutics SA and Redmile LLC 8-K 001-39071 10.1 January 24, 2024
4.2 Form of Indenture F-3 333-270570 4.2 March 15, 2023
4.3* Form of Note
4.4* Form of Warrant Agreement
4.5* Form of Subscription Rights Agreement
4.6* Form of Purchase Contract
4.7* Form of Unit Agreement
5.1 Opinion of Homburger AG, Swiss counsel of ADC Therapeutics SA
5.2 Opinion of Davis Polk & Wardwell LLP, U.S. counsel of ADC Therapeutics SA
23.1 Consent of PricewaterhouseCoopers SA, independent registered public accounting firm
23.2 Consent of Homburger AG (included in Exhibit 5.1)
23.3 Consent of Davis Polk & Wardwell LLP (included in Exhibit 5.2)
24.1 Powers of attorney (included on signature page to the registration statement)
25.1† Statement of Eligibility on Form T-1
107 Filing fee table
* To be filed by amendment or as an exhibit to a document to be incorporated by reference herein in connection with an offering of securities.
To be filed in accordance with the requirements of Section 305(b)(2) of the Trust Indenture Act.

Item 17. Undertakings

The undersigned registrant hereby undertakes:

(a) to file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(1) to include any prospectus required by Section 10(a)(3) of the Securities Act;

(2) to reflect in the prospectus any facts or events arising after the effective date of this registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the "Calculation of Filing Fee Tables" or "Calculation of Registration Fee" table, as applicable, in the effective registration statement; and

II-2

(3) to include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1), (a)(2) and (a)(3) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(b) that, for purposes of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof;
(c) to remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering;
(d) that, for the purpose of determining liability under the Securities Act to any purchaser:

(1) each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(2) each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date; and

(e) that, for the purpose of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(1) any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(2) any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

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(3) the portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(4) any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fideoffering thereof.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer, or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless, in the opinion of its counsel, the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question of whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under Section 310(a) of the Trust Indenture Act ("Trust Indenture Act") in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended (the "Securities Act"), the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the municipality of Epalinges, Switzerland on August 6, 2024.

ADC THERAPEUTICS SA
By: /s/ Ameet Mallik
Name: Ameet Mallik
Title: Chief Executive Officer

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Ameet Mallik, Jose "Pepe" Carmona and Peter J. Graham and each of them, individually, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead in any and all capacities, in connection with this registration statement, including to sign in the name and on behalf of the undersigned, this registration statement and any and all amendments thereto, including post-effective amendments and registrations filed pursuant to Rule 462 under the Securities Act, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the U.S. Securities and Exchange Commission, granting unto such attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or his substitute, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons on August 6, 2024 in the capacities indicated:

Name Title
/s/ Ameet Mallik

Chief Executive Officer and Director

(principal executive officer)

Ameet Mallik
/s/ Jose "Pepe" Carmona

Chief Financial Officer

(principal financial officer)

Jose "Pepe" Carmona
/s/ Lisa Kallebo

Corporate Controller and Chief Accounting Officer

(principal accounting officer)

Lisa Kallebo
/s/ Ron Squarer Chairperson of the Board of Directors
Ron Squarer
/s/ Robert Azelby Director
Robert Azelby
/s/ Jean-Pierre Bizzari Director
Jean-Pierre Bizzari
/s/ Peter Hug Director
Peter Hug
/s/ Viviane Monges Director
Viviane Monges
/s/ Thomas Pfisterer Director
Thomas Pfisterer
/s/ Tyrell J. Rivers Director
Tyrell J. Rivers
/s/ Victor Sandor Director
Victor Sandor
/s/ Jose "Pepe" Carmona Authorized Representative in the United States
Jose "Pepe" Carmona
ADC Therapeutics America, Inc.

Disclaimer

ADC Therapeutics SA published this content on 06 August 2024 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 06 August 2024 20:39:43 UTC.

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