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As filed with the Securities and Exchange Commission on April 18, 2025

Registration No. 333-

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3
REGISTRATION STATEMENT
UNDER THE SECURITIES ACT OF 1933

ADAPTIMMUNE THERAPEUTICS PLC

(Exact name of registrant as specified in its charter)

England and Wales
(State or other jurisdiction of
incorporation or organization)

Not Applicable
(I.R.S. Employer
Identification No.)

60 Jubilee Avenue,
Milton Park Abingdon, Oxfordshire OX14 4RX
United Kingdom
(44) 1235 430000

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

ADAPTIMMUNE LLC
351 Rouse Boulevard,
The Navy Yard Philadelphia, PA 19112
United States of America
(215) 825 9260

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

Please send copies of all communications to:

David S. Bakst, Esq.
Mayer Brown LLP
1221 Avenue of the Americas
New York, New York 10020
Telephone: (212) 506-2500
Facsimile: (212) 849-5551
Facsimile: (44) 1235 430001

Adrian Rawcliffe,
Chief Executive Officer Adaptimmune Therapeutics plc
60 Jubilee Avenue,
Milton Park Abingdon,
Oxfordshire, OX14 4RX United Kingdom
Telephone: (44) 1235 430000

Approximate date of commencement of proposed sale to the public:
From time to time after the effective date 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 of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

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EXPLANATORY NOTE

The Company has an existing registration statement on Form S-3 (File No. 333- 264208) that was declared effective on April 22, 2022 (the “Prior Registration Statement”), and which expires with respect to certain securities registered thereon on April 21, 2025 pursuant to Rule 415(a)(5). In accordance with Rule 415(a)(5) and Rule 415(a)(6), by filing this registration statement on Form S-3, the Company may continue to offer and sell such securities covered by the Prior Registration Statement during the period afforded by Rule 415(a)(5).

This registration statement contains two prospectuses:

•

a base prospectus which covers the offering, issuance and sale of up to $400,000,000 of the Company’s ADSs, warrants and units; and

•

a sales agreement prospectus supplement covering the offering, issuance and sale of up to $200,000,000 of the Company’s ADSs that may be issued and sold under the Sales Agreement dated April 8, 2022 (the “Original Sales Agreement”), as amended on April 18, 2025 between the Company and TD Securities (USA) LLC (as successor to Cowen and Company, LLC) (“TD Cowen”) (the “Amended Sales Agreement”).

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The sales agreement prospectus supplement immediately follows the base prospectus. The $200,000,000 of ADSs that may be offered, issued and sold under the sales agreement prospectus supplement are included in the $400,000,000 of securities that may be offered, issued and sold by the Company under the base prospectus. Upon termination of the sales agreement, any portion of the $200,000,000 included in the sales agreement prospectus supplement that is not sold pursuant to the sales agreement will be available for sale in other offerings pursuant to the base prospectus.

On April 8, 2022, the Company filed a sales agreement prospectus supplement (the “Original Sales Agreement Prospectus”) covering the offering, issuance and sale of up to a maximum aggregate offering price of $200,000,000 of ADSs that could be issued and sold from time to time under the Original Sales Agreement. As of immediately prior to the filing of this registration statement, $154,719,192 of ADSs remained available for sale under the Original Sales Agreement Prospectus. The Amended Sales Agreement amends the Original Sales Agreement, and, upon effectiveness of this registration statement, the remaining $154,719,192 ADSs available for sale under the Original Sales Agreement Prospectus is included for sale under the sales agreement prospectus supplement forming part of this registration statement and no further sales will be made under the Original Sales Agreement Prospectus.

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The information in this prospectus is not complete and may be changed. We may not sell these securities 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 state where the offer or sale is not permitted.

PROSPECTUSSubject to completion, dated April 18, 2025

$400,000,000

American Depositary Shares representing Ordinary Shares

Warrants

Units

We may offer, from time to time, any combination of the securities described in this prospectus, up to an aggregate amount of $400,000,000.

We will provide you with the specific amount, price and terms of the applicable offered securities in one or more supplements to this prospectus. You should carefully read this prospectus and the applicable prospectus supplement, as well as the documents incorporated or deemed to be incorporated by reference in this prospectus, before you purchase any of the securities offered hereby.

We may offer and sell these securities in the same offering or in separate offerings, to or through underwriters, dealers, and agents, or directly to purchasers. The names of any underwriters, dealers, or agents involved in the sale of our securities, their compensation and any options to purchase additional securities held by them will be described in the applicable prospectus supplement. See “Plan of Distribution.”

Our American Depositary Shares, or ADSs, are listed on The Nasdaq Global Select Market under the symbol “ADAP.” On April 17, 2025, the last reported sales price per ADS on The Nasdaq Global Select Market was $0.23. We will provide information in any applicable prospectus supplement regarding any listing of securities other than our ordinary shares on any securities exchange.

Investing in our securities involves risks. See “Risk Factors” on page 6 of this prospectus and any similar section contained in the applicable prospectus supplement or any documents we incorporate by reference concerning factors you should consider before investing in our securities.

Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is , 2025.

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ABOUT THIS PROSPECTUS

This prospectus is part of a shelf registration statement that we filed with the Securities and Exchange Commission, which we refer to as the “SEC,” utilizing a “shelf” registration process. Under this shelf registration process, we may, over time, offer and sell the securities described in this prospectus in one or more offerings, up to a total dollar amount of $400,000,000, as described in this prospectus. This prospectus provides you with a general description of the securities that may be offered. Each time we offer securities under this prospectus, we will provide a prospectus supplement or other offering materials that will contain specific information about the terms of that offering. We may also add, update or change information contained in this prospectus by means of a prospectus supplement or by incorporating by reference information that we file or furnish to the SEC. The registration statement that we filed with the SEC includes exhibits that provide more detail on the matters discussed in this prospectus. If the information in this prospectus is inconsistent with a prospectus supplement, you should rely on the information in that prospectus supplement. Please carefully read this prospectus and any prospectus supplement, together with the additional information described under the headings “Where You Can Find More Information” and “Incorporation by Reference,” before purchasing any securities.

You should rely only on the information contained or incorporated by reference in this prospectus, any prospectus supplement and any issuer free writing prospectus. “Incorporated by reference” means that we can disclose important information to you by referring you to another document filed separately with the SEC. We have not authorized any other person to provide you with different information. If anyone provides you with different information, you should not rely on it. We are not making an offer of these securities in any state or jurisdiction where the offer is not permitted. You should only assume that the information in this prospectus or in any prospectus supplement or issuer free writing prospectus is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus, any applicable prospectus supplement and the information incorporated herein or therein by reference contains market data, industry statistics and other data that have been obtained or compiled from information made available by independent third parties. This prospectus, any applicable prospectus supplement and the information incorporated herein or therein by reference include trademarks, service marks and trade names owned by us or other companies. Solely for convenience, we may refer to our trademarks included or incorporated by reference in this prospectus, any applicable prospectus supplement or any free writing prospectus without the TM or ® symbols, but any such references are not intended to indicate that we will not assert, to the fullest extent permitted under applicable law, our rights to our trademarks or other intellectual property. All trademarks, service marks and trade names included or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus are the property of their respective owners.

In this prospectus, “Adaptimmune,” the “Group,” the “Company,” “we,” “us” and “our” refer to Adaptimmune Therapeutics plc and its consolidated subsidiaries, except where the context otherwise requires. “Adaptimmune®” and “SPEAR®” are registered trademarks of Adaptimmune.

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WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of a registration statement we filed with the SEC. This prospectus does not contain all of the information set forth in the registration statement and the exhibits to the registration statement. For further information with respect to us and the securities we are offering under this prospectus, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement. You should rely only on the information contained in this prospectus or incorporated by reference in this prospectus. We have not authorized anyone else to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date on the front page of this prospectus, regardless of the time of delivery of this prospectus or any sale of the securities offered by this prospectus.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the internet at the SEC’s website at http://www.sec.gov.

Copies of certain information filed by us with the SEC are also available on our website at www.adaptimmune.com. Our website and the information contained or connected to our website is not incorporated by reference in this prospectus or any prospectus supplement, and you should not consider it part of this prospectus or any prospectus supplement.

We will furnish to Citibank, N.A., as depositary bank of our ADSs, our annual reports. When the depositary bank receives these reports, it will upon our request promptly provide them to all holders of record of ADSs or otherwise make such reports available to such ADS holders in accordance with the terms of the deposit agreement. We will also furnish the depositary bank with all notices of shareholders’ meetings and other reports and communications in English that we make available to our shareholders. The depositary bank will make these notices, reports and communications available to holders of ADSs and will upon our request mail to all holders of record of ADSs the information contained in any notice of a shareholders’ meeting it receives.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference information into this document. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934 between the date of the initial registration statement and the effectiveness of the registration statement and thereafter until the termination or completion of the offering of the securities described in this prospectus (other than information in such filings that was “furnished,” under applicable SEC rules, rather than “filed”).

These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements.

We incorporate by reference the following documents or information that we have filed with the SEC:

•

our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the SEC on March 24, 2025 (the “2024 Form 10-K”);

•

our Current Reports on Form 8-K filed with the SEC on March 24, 2025 and April 14, 2025; and

•

the description of our ordinary shares and ADSs contained in our registration statement on Form 8-A, filed with the SEC under the Exchange Act on April 30, 2015, as updated by Exhibit 4.4 to our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, including the “Description of Ordinary Shares” and the “Description of American Depositary Shares” contained therein and any amendment or report filed for the purpose of updating such description.

Any statement contained in this prospectus or contained in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded to the extent that a statement contained in this prospectus or any subsequently filed supplement to this prospectus, or document deemed to be incorporated by reference into this prospectus, modifies or supersedes such statement You may request a copy of these filings at no cost, by writing or telephoning us at the following address:

Adaptimmune Therapeutics plc
Attn: Company Secretary
60 Jubilee Avenue, Milton Park
Abingdon, Oxfordshire OX14 4RX
United Kingdom
(44) 1235 430000

You should rely only on the information incorporated by reference or provided in this prospectus or in any prospectus supplement. We have not authorized anyone else to provide you with different or additional information. An offer of these securities is not being made in any jurisdiction where the offer or sale is not permitted. You should not assume that the information in this prospectus or any prospectus supplement is accurate as of any date other than the date on the front of those documents.

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THE COMPANY

We are a commercial-stage biopharmaceutical company working to redefine the treatment of solid tumor cancers with cell therapies. With the approval by the U.S. Food and Drug Administration (“FDA”) of our first biologics license application for TECELRA® (afamitresgene autoleucel) (“TECELRA”), which is the first engineered T-cell therapy for the treatment of a solid tumor cancer approved in the U.S., we are now focused on its launch and commercialization.

TECELRA is a genetically modified autologous T-cell immunotherapy indicated for the treatment of adults with unresectable or metastatic synovial sarcoma who have received prior chemotherapy, are HLA-A*02:01P, -A*02:02P, -A*02:03P, or -A*02:06P positive and whose tumor expresses the MAGE-A4 antigen as determined by FDA-approved or cleared companion diagnostic devices. This indication is approved under the FDA’s accelerated approval regulations based on overall response rate and duration of response. Continued approval for this indication is contingent upon verification and description of clinical benefits through post-marketing requirements.

We are planning initiation of a BLA submission in late 2025, and if approved by the FDA, commercial launch for our second T-cell immunotherapy, letetresgene autoleucel (“lete-cel”), for people with synovial sarcoma and myxoid liposarcoma in 2026. This product would significantly expand our treatable patient population within our commercial sarcoma franchise with up to $400 million annual peak combined US sales from TECELRA and lete-cel. We estimate that approximately 400 newly diagnosed patients per year are biomarker eligible for TECELRA, and an incremental 600 newly diagnosed synovial sarcoma and myxoid liposarcoma patients per year in the US will be biomarker eligible for lete-cel.

In addition to our commercial sarcoma franchise we remain committed to our collaboration with Galapagos NV (“Galapagos”) which uses our uzatresgene autoleucel candidate manufactured using the Galapagos manufacturing process. A clinical trial authorization to start a Phase 1 trial in head and neck cancer is planned for 2025.

All of our products and clinical candidates utilize engineered T-cells designed to find and destroy cancer cells in patients. The T-cells are engineered to recognize particular antigens expressed by the cancer cells and to activate a person’s immune system to fight the cancer they have. Our current products and clinical candidates are personalized treatment options where we take a person’s white blood cells, modify them to express the engineered T-cells and then return those engineered T-cells to the patient.

Corporate Information

Adaptimmune Therapeutics plc was incorporated on December 3, 2014 and is a public limited company incorporated under the laws of England and Wales. Our registered and principal executive offices are located at 60 Jubilee Avenue, Milton Park, Abingdon, Oxfordshire OX14 4RX, United Kingdom, our general telephone number is (+44) 1235 430000 and our corporate website address is www.adaptimmune.com. Our website and the information contained on or accessible through our website are not part of this document. We have included our website address in this prospectus solely as an inactive textual reference. Our agent for service of process in the United States is Adaptimmune LLC, located at 351 Rouse Boulevard, The Navy Yard, Philadelphia PA 19112, United States.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the financial statements and other documents incorporated by reference in this prospectus and any related prospectus supplement may contain forward-looking statements that involve risks and uncertainties, as well as assumptions that, if they never materialize or prove incorrect, could cause our results to differ materially from those expressed or implied by such forward-looking statements. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. All statements other than statements of historical facts contained in such documents are forward-looking statements. In some cases, you can identify forward-looking statements by words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect” or the negative of these words or other comparable terminology.

Any forward-looking statements in this prospectus and in the documents incorporated by reference in this prospectus and any related prospectus supplement reflect our current views with respect to future events or to our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, among other things, those listed under Part I, Item 1A. Risk Factors in our 2024 Form 10-K, which is incorporated by reference herein, as updated by our other SEC filings filed after such annual report. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Except as required by law, we assume no obligation to update or revise these forward-looking statements for any reason, even if new information becomes available in the future.

Projections, market research or similar methodologies are inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by third parties, industry, medical and general publications, government data and similar sources.

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RISK FACTORS

An investment in our securities involves risks. We urge you to carefully consider all of the information contained in or incorporated by reference in this prospectus and other information which may be incorporated by reference in this prospectus or any prospectus supplement as provided under “Incorporation of Certain Information by Reference,” including the risks described under “Risk Factors” in Item 1A of our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. This prospectus also contains forward-looking statements that involve risks and uncertainties. Please read “Special Note on Forward-Looking Statements.” Our actual results could differ materially from those anticipated in the forward-looking statements as a result of certain factors, including the risks described elsewhere in this prospectus or any prospectus supplement and in the documents incorporated by reference into this prospectus or any prospectus supplement. If any of these risks occur, our business, financial condition or results of operation could be adversely affected. As a result, you could lose all or part of your investment.

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USE OF PROCEEDS

We currently intend to use the net proceeds from the sales of securities offered hereby, if any, for general corporate purposes, which may include commercialization expenses, research and development expenses, working capital and general and administrative expenses, unless specified otherwise in the applicable prospectus supplement.

Our expected use of net proceeds from the sales of securities offered hereby, if any, represents our current intentions based upon our present plans and business conditions. As of the date of this prospectus, we cannot predict with certainty all of the particular uses for the net proceeds to be received upon the completion of any sales of securities offered hereby or the amounts that we will actually spend on the uses set forth above. The amounts and timing of our actual use of net proceeds will vary depending on numerous factors, including our ability to obtain additional financing, the relative success and cost of our commercialization of TECELRA, our ability to commercialize lete-cel, the relative success and cost of our research, preclinical and clinical development programs, including a change in our planned course of development or the termination of a clinical program necessitated by the results of data received from clinical trials or otherwise, the results of our collaboration agreement with Galapagos and whether we enter into future collaborations. As a result, management will have broad discretion in the application of the net proceeds, and investors will be relying on our judgment regarding the application of the net proceeds of this offering.

Pending their use, we plan to invest the net proceeds from this offering in short or medium-term interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.K. or U.S. governments.

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DESCRIPTION OF SHARE CAPITAL

The following summary describes our share capital, certain material provisions of our articles of association, and certain applicable provisions of the U.K. Companies Act 2006 (the “Companies Act 2006”). The following summary does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the applicable provisions of English law and our articles of association, a copy of which has been previously filed with the SEC. We encourage you to read our articles of association and the applicable provisions of English law for additional information.

General

We may issue additional ordinary shares from time to time. Effective from May 14, 2024, our board of directors were authorized pursuant to Section 551 of the Companies Act 2006 to allot new shares or to grant rights to subscribe for or to convert any security into shares in the Company up to a maximum aggregate nominal amount of £505,881.00. This authority (unless previously renewed, varied or revoked) will expire on the earlier of the conclusion of the Company’s annual general meeting in 2025 and June 30, 2025. In addition, statutory preemption rights under Section 561(1) of the Companies Act 2006 have been disapplied in respect of new ordinary shares issued or rights to subscribe for, or convert securities into, new ordinary shares granted pursuant to such authority. This authorization and disapplication of preemption rights was utilized, inter alia, for the purposes of sales of 6,357,804 ADSs representing 38,146,824 ordinary shares in at-the-market offerings through April 17, 2025. To the extent that this authorization and disapplication do not remain unutilized in a sufficient amount for the purposes of an offering of the securities described in this prospectus, our directors will require a further authorization for the purpose of s551 of the Companies Act 2006 and disapplication of statutory preemption rights under s561(1) of the Companies Act 2006 to be granted by our shareholders in general meeting prior to proceeding with that offering.

As of April 17, 2025 the number of issued and outstanding ordinary shares of nominal value £0.001 per share, of the Registrant is 1,582,176,204. Each issued ordinary share has been fully paid. There are currently no preferred shares outstanding. All ordinary shares have the same rights and rank pari passu in all respects. Subject to the provisions of the Companies Act 2006 and any other relevant legislation, our shares may be issued with such preferred, deferred or other rights, or such restrictions, whether in relation to dividends, returns of capital, voting or otherwise, as we may determine by ordinary resolution (or, failing any such determination, as the directors may determine).

Holders of our ADSs will not be treated as shareholders and their names will therefore not be entered in our share register. The depositary, the Custodian or their nominees will be the holder of the ordinary shares underlying our ADSs. For discussion on our ADSs and ADS holder rights see “Description of American Depositary Shares” in this prospectus. Holders of our ADSs have a right to receive the ordinary shares underlying their ADSs as discussed in “Description of American Depositary Shares” in this prospectus.

Ordinary Shares

Voting Rights

Subject to any other provisions of our articles of association and without prejudice to any special rights, privileges or restrictions as to voting attached to any shares forming part of our share capital, the voting rights of shareholders are as follows. On a show of hands, each shareholder present in person, and each duly authorized representative present in person of a shareholder that is a corporation, has one vote. On a show of hands, each proxy present in person who has been duly appointed by one or more shareholders entitled to vote on the resolution has one vote, but a proxy has one vote for and one vote against a resolution if, in certain circumstances, the proxy is instructed by more than one shareholder entitled to vote on the resolution to vote in different ways on a resolution. On a poll, each shareholder present in person or by proxy or (being a corporation) by a duly authorized representative has one vote for each share held by the shareholder. We are prohibited (to the extent specified by the Companies Act 2006) from exercising any rights to attend or vote at meetings in respect of any shares held by Adaptimmune as treasury shares.

Under English law, an ordinary resolution is passed on a show of hands if it is approved by a simple majority (more than 50%) of the votes cast by shareholders present (in person or by proxy) at the meeting

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and entitled to vote on the resolution. If a poll is demanded, an ordinary resolution is passed if it is approved by holders representing a simple majority of the total voting rights of shareholders present (in person or by proxy) who (being entitled to vote) vote on the resolution. Special resolutions require the affirmative vote of not less than 75% of the votes cast by shareholders present (in person or by proxy) at the meeting.

Restrictions on Voting Where Sums Overdue on Shares

None of our shareholders (whether present in person by proxy or, in the case of a corporate member, by a duly authorized representative) shall (unless the directors otherwise determine) be entitled to vote or to exercise any other right of membership at any general meeting or at any separate class meeting in respect of any share held by him or her unless all calls or other sums payable by him or her in respect of that share have been paid.

Calls on Shares

The directors may from time to time make calls on shareholders in respect of any moneys unpaid on their shares, whether in respect of the nominal value of the shares or by way of premium. Shareholders are required to pay called amounts on shares subject to receiving at least 14 clear days’ notice specifying the time and place for payment. If a shareholder fails to pay any part of a call, the directors may serve further notice naming another day not being less than 14 clear days from the date of the further notice requiring payment and stating that in the event of non-payment the shares in respect of which the call was made will be liable to be forfeited. Subsequent forfeiture requires a resolution by the directors.

Dividend Rights

Subject to the Companies Act 2006 and the provisions of all other relevant legislation, we may by ordinary resolution declare dividends in accordance with the respective rights of shareholders but no such dividend shall exceed the amount recommended by the directors. If, in the opinion of the directors, our profits available for distribution justify such payments, the directors may pay fixed dividends payable on any of our shares with preferential rights, half-yearly or otherwise, on fixed dates and from time to time pay interim dividends to the holders of any class of shares. Subject to any special rights attaching to or terms of issue of any shares, all dividends shall be declared and paid according to the amounts paid up on the shares on which the dividend is paid. No dividend shall be payable to us in respect of any shares held by us as treasury shares (except to the extent permitted by the Companies Act 2006 and any other relevant legislation). We may, upon the recommendation of the directors, by ordinary resolution, direct payment of a dividend wholly or partly by the distribution of specific assets.

The directors may, if so authorized by ordinary resolution passed at any general meeting, offer any holders of our ordinary shares the right to elect to receive in lieu of that dividend (or part of any of that dividend) an allotment of our ordinary shares credited as fully paid.

We or the directors may by resolution specify a “record date” on which persons registered as the holders of shares shall be entitled to receipt of any dividend.

Distributions of Assets on Winding-up

Subject to any special rights attaching to or the terms of issue of any shares, on any winding-up of the Company our surplus assets remaining after satisfaction of our liabilities will be distributed among our shareholders in proportion to their respective holdings of shares and the amounts paid up on those shares.

On any winding-up of the Company (whether the liquidation is voluntary, under supervision or by the Court, the liquidator may with the authority of a special resolution of the Company and any other sanction required by any relevant legislation, divide among our shareholders (excluding the Company itself to the extent that it is a shareholder by virtue of its holding any shares or treasury shares) in specie or in kind the whole or any part of our assets (subject to any special rights attached to any shares issued by us in the future) and may for that purpose set such value as the liquidator deems fair upon any one or more class or classes of property and may determine how that division shall be carried out as between the shareholders or different

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classes of shareholders. The liquidator may, with that sanction, vest the whole or any part of the assets in trustees upon such trusts for the benefit of the shareholders as the liquidator with the relevant authority determines, and the liquidation of the Company may be closed and the Company dissolved, but so that no shareholders shall be compelled to accept any shares or other property in respect of which there is a liability.

Variation of Rights

The rights or privileges attached to any class of shares may (unless otherwise provided by the terms of the issue of the shares of that class) be varied or abrogated with the consent in writing of the holders of three-fourths in requisite amount of the issued shares of that class (excluding any shares of that class held as treasury shares) or with the sanction of a special resolution passed at a separate general meeting of the shareholders of that class, but not otherwise.

Transfer of Shares

All of our shares are in registered form and may be transferred by a transfer in any usual or common form or any form acceptable to the directors and permitted by the Companies Act 2006 and any other relevant legislation.

The directors may decline to register a transfer of a share that is:

•

not fully paid or on which we have a lien;

•

(except where uncertificated shares are transferred without a written instrument) not lodged duly stamped (if it is required to be duly stamped) at our registered office or at such other place as the directors may appoint;

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(except where a certificate has not been issued) not accompanied by the certificate of the share to which it relates or such other evidence reasonably required by the directors to show the right of the transferor to make the transfer;

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in respect of more than one class of share; or

•

in the case of a transfer to joint holders of a share, the number of joint holders to whom the share is to be transferred exceeds four.

Capital Variations

We may, by ordinary resolution, consolidate and divide all or any of our share capital into shares of a larger nominal amount than our existing shares or sub-divide our shares, or any of them, into shares of a smaller amount than our existing shares. Subject to the provisions of the Companies Act 2006 and any other relevant legislation, we may by special resolution reduce our share capital, any capital redemption reserve fund or any share premium account and may redeem or purchase any of our own shares.

Pre-emption Rights

There are no rights of pre-emption under our articles of association in respect of transfers of issued ordinary shares. In certain circumstances, our shareholders may have statutory pre-emption rights under the Companies Act 2006 in respect of the allotment of new shares in the Company for cash. These statutory pre-emption rights, when applicable, would require us to offer new shares for allotment to existing shareholders on a pro rata basis before allotting them to other persons. In such circumstances, the procedure for the exercise of such statutory pre-emption rights would be set out in the documentation by which such ordinary shares would be offered to our shareholders. These statutory pre-emption rights may be disapplied by a special resolution passed by shareholders in a general meeting in accordance with the provisions of the Companies Act 2006.

Preferred Shares

Subject to the provisions of the Companies Act 2006 and any other relevant legislation, we may issue shares with such preferred, deferred or other rights, or such restrictions, whether in relation to dividends,

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returns of capital, voting or otherwise, as we may determine by ordinary resolution (or, failing any such determination, as the directors may determine). Any or all of such rights and restrictions may be greater than the rights of the ordinary shares. Holders of preferred shares may be entitled to receive a preference payment in the event of our liquidation before any payment is made to the holders of ordinary shares. There are currently no preferred shares outstanding, and we have no present intention to issue any preferred shares.

Directors

Number

Unless and until we in a general meeting of our shareholders otherwise determine, the number of directors shall not be subject to any maximum but shall not be less than two.

Borrowing Powers

Under our directors’ general power to manage our business, our directors may exercise all the powers of the Company to borrow money and to mortgage or charge our undertaking, property and uncalled capital or parts thereof and to issue debentures and other securities, whether outright or as collateral security for any debt, liability or obligation of the Company or of any third party.

Directors’ Interests and Restrictions

(a)

The board may, in accordance with our articles of association and the requirements of the Companies Act 2006, authorize a matter proposed to us which would, if not authorized, involve a breach by a director of his or her duty under section 175 of the Companies Act 2006 to avoid a situation in which the director has, or can have, a direct or indirect interest that conflicts, or possibly may conflict, with our interests. A director is not required, by reason of being a director, to account to the Company for any remuneration or other benefit that the director derives from a relationship involving a conflict of interest or possible conflict of interest that has been authorized by the board.

(b)

Subject to the provisions of any relevant legislation and provided that he or she has disclosed to the directors the nature and extent of any material interest of his or hers, a director may be a party to, or otherwise interested in, any transaction, contract or arrangement with us and he or she may be a director or other officer of, or employed by, or a party to any transaction or arrangement with, or otherwise interested in anybody corporate promoted by the Company or in which the Company is otherwise interested and that director shall not, by reason of his or her office, be accountable to the Company for any benefit that the director derives from any such office or employment or from any such transaction or arrangement or from any interest in any such body corporate; and no such transaction or arrangement shall be liable to be voided on the ground of any such interest or benefit.

(c)

Except as provided in our articles of association, a director shall not vote at a meeting of the directors in respect of any transaction or arrangement or any other proposal whatsoever in which he or she has an interest (together with any person connected with him or her within the meaning of section 252 of the Companies Act 2006), other than (i) an interest in shares or debentures or other securities of the Company, (ii) where permitted by the terms of any authorization of a conflict of interest or by an ordinary resolution, (iii) where the interest cannot reasonably be regarded as likely to give rise to a conflict of interest, or (iv) in the circumstances set out in paragraph (d) below, and shall not be counted in the quorum at a meeting in relation to any resolution on which the director is not entitled to vote.

(d)

A director shall (in the absence of some material interest other than those indicated below) be entitled to vote (and be counted in the quorum) in respect of any resolution concerning any of the following matters:

(i)

the giving of any guarantee, security or indemnity in respect of an obligation incurred by him or her or for the benefit us or any of our subsidiaries;

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(ii)

any proposal concerning an offer of shares or debentures or other securities of or by us or any of our subsidiaries for subscription or purchase or exchange in which offer the director is or will be interested as a participant in the underwriting, sub-underwriting or guaranteeing of such offer;

(iii)

any proposal concerning any other company in which the director is interested, directly or indirectly and whether as an officer or shareholder or otherwise, provided that the director (together with persons connected with him or her) does not to his or her knowledge hold an interest in shares representing one percent or more of the issued shares of any class of such company (or of any third company through which his or her interest is derived) or of the voting rights available to shareholders of the relevant company;

(iv)

any proposal concerning arrangements pursuant to which benefits are made available to our employees and/or directors and which does not provide special benefits for directors or former directors;

(v)

any proposal under which the director may benefit concerning the giving of indemnities to our directors or other officers that the directors are empowered to give under our articles of association;

(vi)

any proposal under which the director may benefit concerning the purchase or maintenance of insurance for any of our directors or other officers; and

(vii)

any proposal under which the director may benefit concerning the provision to directors of funds to meet expenditures in defending proceedings.

(e)

Where proposals are under consideration to appoint two or more directors to offices or employments with us or with any company in which we are interested or to fix or vary the terms of such appointments, such proposals may be divided and considered in relation to each director separately and in such case each of the directors concerned (if not debarred from voting under paragraph (d)(iv) above) shall be entitled to vote (and be counted in the quorum) in respect of each resolution, except that concerning his or her own appointment.

(f)

If any question shall arise at any meeting as to the materiality of a director’s interest or as to the entitlement of any director to vote and such question is not resolved by the director agreeing voluntarily to abstain from voting, such question shall be referred to the chairman of the meeting (or where the interest concerns the chairman himself to the deputy chairman of the meeting) and his ruling in relation to any director shall be final and conclusive, except in a case where the nature or extent of the interests of the director concerned have not been fairly disclosed.

Remuneration

(a)

Each of the directors may (in addition to any amounts payable under paragraph (b) and (c) below or under any other provision of our articles of association) be paid out of the funds of the Company such sum by way of directors’ fees as the directors may from time to time determine.

(b)

Any director who is appointed to hold any employment or executive office with us or who, by our request, goes or resides abroad for any purposes of the Company or who otherwise performs services that in the opinion of the directors are outside the scope of his or her ordinary duties may be paid such additional remuneration (whether by way of salary, commission, participation in profits or otherwise) as the directors (or any duly authorized committee of the directors) may determine and either in addition to or in lieu of any remuneration provided for by or pursuant to any other Article.

(c)

Each director may be paid his or her reasonable traveling expenses (including hotel and incidental expenses) of attending and returning from meetings of the directors or committees of the directors or general meetings or any separate meeting of the holders of any class of our shares or any other meeting that as a director he or she is entitled to attend and shall be paid all expenses properly and reasonably incurred by him or her in the conduct of the Company’s business or in the discharge of his or her duties as a director.

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Pensions and Other Benefits

The directors may exercise all the powers of the Company to provide benefits, either by the payment of gratuities or pensions or by insurance or in any other manner whether similar to the foregoing or not, for any director or former director, or any person who is or was at any time employed by, or held an executive or other office or place of profit in, the Company or anybody corporate that is or has been a subsidiary of the Company or a predecessor of the business of the Company or of any such subsidiary and for the families and persons who are or was a dependent of any such persons and for the purpose of providing any such benefits contribute to any scheme trust or fund or pay any premiums.

Appointment and Retirement of Directors

(a)

The directors shall have power to appoint any person who is permitted by the Companies Act 2006 and any other relevant legislation and is willing to act to be a director, either to fill a casual vacancy or as an additional director but so that the total number of directors shall not exceed the maximum number fixed (if any) by or in accordance with our articles of association. Any director so appointed shall retire from office at our annual general meeting following such appointment. Any director so retiring shall be eligible for re-election.

(b)

Subject as provided in our articles of association, the shareholders may by ordinary resolution elect any person who is willing to act as a director either to fill a casual vacancy or as an addition to the existing directors or to replace a director removed from office under our articles of association but so that the total number of directors shall not at any one time exceed any maximum number fixed by or in accordance with our articles of association.

(c)

At each annual general meeting a minimum number equal to one-third of the number of those directors who are not due to retire at the annual general meeting under sub-paragraph (a) above (referred to for as the purposes of this paragraph relevant directors) (or, if their number is not a multiple of three, the number nearest to but not greater than one-third) shall retire from office. Directors retiring under paragraph (e) below shall be counted as part of this minimum number.

(d)

The directors to retire by rotation pursuant to paragraph (c) above shall include (so far as necessary to obtain the minimum number required and after taking into account the directors to retire under paragraph (e) below) any relevant director who wishes to retire and not to offer himself for re-election. Any further directors to retire shall be those of the other relevant directors who have been longest in office since their last re-election or appointment and so that as between persons who became or were last re-elected directors on the same day, those to retire shall (unless they otherwise agree among themselves) be determined by lot. A retiring director shall be eligible for re-election.

(e)

In any event, each director shall retire and shall (unless his or her terms of appointment with the Company specify otherwise) be eligible for re-election at the annual general meeting held in the third calendar year (or such earlier calendar year as may be specified for this purpose in his or her terms of appointment with the Company) following his or her last appointment, election or re- election at any general meeting of the Company.

(f)

At the meeting at which a director retires under any provision of our articles of association, the shareholders may by ordinary resolution fill the vacated office by appointing a person eligible for election as a director under our articles of association to it, and in default the retiring director shall be deemed to have been re-appointed except where:

(i)

that director has given notice to us that he or she is unwilling to be elected; or

(ii)

at such meeting it is expressly resolved not to fill such vacated office or a resolution for the reappointment of such director shall have been put to the meeting and not passed.

(g)

In the event of the vacancy not being filled at such meeting, it may be filled by the directors as a casual vacancy in accordance with sub-paragraph (a) above.

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(h)

The retirement of a director pursuant to paragraphs (c), (d) and (e) shall not have effect until the conclusion of the relevant meeting except where a resolution is passed to elect some other person in the place of the retiring director or a resolution for his or her re-election is put to the meeting and not passed and accordingly a retiring director who is re-elected or deemed to have been re- elected will continue in office without break.

Company Name

The directors may resolve to change the Company’s name.

Indemnity of Officers

Subject to the provisions of any relevant legislation, each of our directors and other officers (excluding an auditor) are entitled to be indemnified by us against all liabilities incurred by him or her in the execution and discharge of his or her duties or in relation to those duties. The Companies Act 2006 renders void an indemnity for a director against any liability attaching to him or her in connection with any negligence, default, breach of duty or breach of trust in relation to the company of which he or she is a director.

General Meetings and Notices

Annual General Meetings

We shall in each year hold a general meeting of our shareholders in addition to any other meetings in that year, and shall specify the meeting as such in the notice convening it. The annual general meeting shall be held at such time and place as the directors may appoint.

Calling of General Meetings

The directors may call a general meeting of shareholders. The directors must call a general meeting if the shareholders and the Companies Act 2006 require them to do so.

Quorum of Meetings

No business shall be transacted at any general meeting unless a quorum is present when the meeting proceeds to business but the absence of a quorum shall not preclude the appointment of a chairman that shall not be treated as part of the business of a meeting. One or more qualifying persons present at a meeting and between them holding (or being the proxy or corporate representative of the holders of) at least one-third in number of the issued shares (excluding any shares held as treasury shares) entitled to vote on the business to be transacted are a quorum. A qualifying person for these purposes is an individual who is a member, a person authorized to act as the representative of a member (being a corporation) in relation to the meeting or a person appointed as proxy of a member in relation to the meeting.

Other U.K. Law Considerations

Mandatory Purchases and Acquisitions

Pursuant to sections 979 to 991 of the Companies Act 2006, where a takeover offer has been made for the Company and the offeror has acquired or unconditionally contracted to acquire not less than 90 percent in value of the shares to which the offer relates and, in a case where the shares to which the offer relates are voting shares, not less than 90 percent of the voting rights carried by those shares, the offeror may give notice, to the holder of any shares to which the offer relates which the offeror has not acquired or unconditionally contracted to acquire that he or she wishes to acquire and is entitled to so acquire, to acquire those shares of the same terms as the general offer. Where a takeover offer has been made for the Company, the holder of any voting shares to which the offer relates who has not accepted the offer may require the offeror to acquire those shares if, at any time before the end of the period within which the offer can be accepted, the offeror has acquired or unconditionally contracted to acquire some (but not all) of the shares to which the offer relates and those shares amount to not less than 90 percent in value of the voting shares to which the

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offer relates and carry not less than 90 percent of the voting rights in the company. The holder of any non-voting shares to which the offer relates who has not accepted the offer may require the offeror to acquire those shares if, at any time before the end of the period within which the offer can be accepted, the offeror has acquired or unconditionally contracted to acquire some (but not all) of the shares to which the offer relates and those shares amount to not less than 90 percent in value of all the shares in the Company.

Disclosure of Interest in Shares

Pursuant to Part 22 of the Companies Act 2006 and our articles of association, we are empowered by notice in writing to require any person whom we know to be, or have reasonable cause to believe to be, interested in our shares or, at any time during the three years immediately preceding the date on which the notice is issued has been so interested, within a reasonable time to disclose to us particulars of any interest, rights, agreements or arrangements affecting any of the shares held by that person or in which such other person as aforesaid is interested (so far as is within his or her knowledge).

Under our articles of association, if a person defaults in supplying us with the required particulars in relation to the shares in question (“default shares”), the directors may by notice direct that:

•

in respect of the default shares, the relevant member shall not be entitled to vote or exercise any other right conferred by membership in relation to general meetings; and/or

•

where the default shares represent at least 0.25 percent of their class, (a) any dividend or other money payable in respect of the default shares shall be retained by us without liability to pay interest, and/or (b) no transfers by the relevant member of shares other than certain approved transfers may be registered (unless the member himself or herself is not in default and the transfer does not relate to default shares), and/or (c) any shares held by the relevant number in uncertificated form shall be converted into certificated form.

Purchase of Own Shares

Under English law, a public limited company may only purchase its own shares out of the distributable profits of the company or the proceeds of a fresh issue of shares made for the purpose of financing the purchase. A limited company may not purchase its own shares if as a result of the purchase there would no longer be any issued shares of the company other than redeemable shares or shares held as treasury shares.

Subject to the above, we may purchase our own shares in the manner prescribed below. We may purchase on a recognized investment exchange our own fully paid shares pursuant to an ordinary resolution of the Company. The resolution authorizing the purchase must:

•

specify the maximum number of shares authorized to be acquired;

•

determine the maximum and minimum prices that may be paid for the shares; and

•

specify a date, not being later than five years after the passing of the resolution, on which the authority to purchase is to expire.

As an overseas exchange, Nasdaq is not a recognized investment exchange for these purposes.

We may purchase our own fully paid shares otherwise than on a recognized investment exchange pursuant to a purchase contract authorized by ordinary resolution of the Company before the purchase takes place. Any authority will not be effective if any shareholder from whom we propose to purchase shares votes on the resolution and the resolution would not have been passed if he or she had not done so. The resolution authorizing the purchase must specify a date, not being later than five years after the passing of the resolution, on which the authority to purchase is to expire.

Takeover Provisions

If at the time of a takeover offer on or before February 2, 2027 the U.K. Panel on Takeovers and Mergers (the “Takeover Panel”) determines that we have our place of central management and control in the United Kingdom, we would be subject to the U.K. City Code on Takeovers and Mergers (the “Takeover

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Code”), which is issued and administered by the Takeover Panel. The Takeover Code provides a framework within which takeovers of companies subject to it are conducted, including, in particular, certain rules in respect of mandatory offers.

In July 2018, the Takeover Panel confirmed that, based on our current circumstances, we are not subject to the Takeover Code. As a result, our shareholders are not entitled to the benefit of certain takeover offer protections provided under the Takeover Code. We believe that this position is unlikely to change at any time in the near future but, in accordance with good practice, we will review the situation on a regular basis and consult with the Takeover Panel if there is any change in our circumstances which may have a bearing on whether the Takeover Panel would determine our place of central management and control to be in the United Kingdom.

Exchange Controls

There are no governmental laws, decrees, regulations or other legislation in the United Kingdom that may affect the import or export of capital, including the availability of cash and cash equivalents for use by us, or that may affect the remittance of dividends, interest, or other payments by us to non-resident holders of our ordinary shares or ADSs representing our ordinary shares, other than withholding tax requirements. There is no limitation imposed by English law or our articles of association on the right of non-residents to hold or vote shares.

Market Listing

Our ADSs are listed on The Nasdaq Global Select Market under the symbol “ADAP.”

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DESCRIPTION OF AMERICAN DEPOSITARY SHARES

Citibank, N.A. (the “Depositary”) has agreed to act as the depositary bank for the American Depositary Shares. Citibank’s depositary offices are located at 388 Greenwich Street, New York, New York 10013. American Depositary Shares are frequently referred to as “ADSs” and represent ownership interests in securities that are on deposit with the depositary bank. ADSs may be represented by certificates that are commonly known as “American Depositary Receipts” or “ADRs.” The depositary bank typically appoints a Custodian to safekeep the securities on deposit. In this case, the Custodian is Citibank, N.A. London Branch, having its principal office at Citigroup Centre, Canada Square, Canary Wharf, London E14 5LB, England.

We have appointed Citibank as depositary bank pursuant to a deposit agreement. A copy of the deposit agreement is on file with the SEC under cover of a Registration Statement on Form F-6. You may obtain a copy of the deposit agreement from the SEC’s website (www.sec.gov). Please refer to Registration Number 333-203642, Registration Number 333-212714 or Registration Number 333-233560 when retrieving such copy.

We are providing you with a summary description of the material terms of the ADSs and of your material rights as an owner of ADSs. Please remember that summaries by their nature lack the precision of the information summarized and that the rights and obligations of an owner of ADSs will be determined by reference to the terms of the deposit agreement and not by this summary. We urge you to review the deposit agreement in its entirety. The portions of this summary description that are italicized describe matters that may be relevant to the ownership of ADSs but that may not be contained in the deposit agreement.

Each ADS represents the right to receive and to exercise the beneficial ownership interests in six ordinary shares, each of which is frequently referred to as a “Share” or collectively, as “Shares”, on deposit with the Custodian. An ADS also represents the right to receive and to exercise the beneficial interests in any other property received by the depositary bank or the Custodian on behalf of the owner of the ADS but that has not been distributed to the owners of ADSs because of legal restrictions or practical considerations. The Custodian, the depositary bank and their respective nominees will hold all deposited property for the benefit of the holders and beneficial owners of ADSs. The deposited property does not constitute the proprietary assets of the depositary bank, the Custodian or their nominees. Beneficial ownership in the deposited property will under the terms of the deposit agreement be vested in the beneficial owners of the ADSs. The depositary bank, the Custodian and their respective nominees will be the record holders of the deposited property represented by the ADSs for the benefit of the holders and beneficial owners of the corresponding ADSs. A Beneficial Owner of ADSs may or may not be the holder of ADSs. Beneficial Owners of ADSs will be able to exercise beneficial ownership interests in the deposited property only through the registered holders of the ADSs, by the registered holders of the ADSs (on behalf of the applicable ADS owners) only through the depositary bank, and by the depositary bank (on behalf of the owners of the corresponding ADSs) directly, or indirectly through the Custodian or their respective nominees, in each case upon the terms of the deposit agreement.

If you become an owner of ADSs, you will become a party to the deposit agreement and therefore will be bound to its terms and to the terms of any ADR that represents your ADSs. The deposit agreement and the ADR specify our rights and obligations as well as your rights and obligations as an owner of ADSs and those of the depositary bank. As an ADS holder, you appoint the depositary bank to act on your behalf in certain circumstances. The deposit agreement and the ADRs are governed by New York law. However, our obligations to the holders of ordinary shares will continue to be governed by the laws of England and Wales, which may be different from the laws in the United States.

In addition, applicable laws and regulations may require you to satisfy reporting requirements and obtain regulatory approvals in certain circumstances. You are solely responsible for complying with such reporting requirements and obtaining such approvals. Neither the depositary bank, the Custodian, us nor any of their or our respective agents or affiliates shall be required to take any actions whatsoever on your behalf to satisfy such reporting requirements or obtain such regulatory approvals under applicable laws and regulations.

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As an owner of ADSs, we will not treat you as one of our shareholders and you will not have direct shareholder rights. The depositary bank will hold on your behalf the shareholder rights attached to the ordinary shares underlying your ADSs. As an owner of ADSs you will be able to exercise the shareholders rights for the ordinary shares represented by your ADSs through the depositary bank only to the extent contemplated in the deposit agreement. To exercise any shareholder rights not contemplated in the deposit agreement you will, as an ADS owner, need to arrange for the cancellation of your ADSs and become a direct shareholder.

Dividends and Distributions

As a holder of ADSs, you generally have the right to receive the distributions we make on the securities deposited with the Custodian. Your receipt of these distributions may be limited, however, by practical considerations and legal limitations. Holders of ADSs will receive such distributions under the terms of the deposit agreement in proportion to the number of ADSs held as of the specified record date, after deduction of the applicable fees, taxes and expenses.

Distributions of Cash

Whenever we make a cash distribution for the securities on deposit with the Custodian, we will deposit the funds with the Custodian. Upon receipt of confirmation of the deposit of the requisite funds, the depositary bank will arrange for the funds to be converted into U.S. dollars and for the distribution of the U.S. dollars to the holders, subject to the laws and regulations of England and Wales.

The conversion into U.S. dollars will take place only if practicable and if the U.S. dollars are transferable to the United States. The depositary bank will apply the same method for distributing the proceeds of the sale of any property (such as undistributed rights) held by the Custodian in respect of securities on deposit.

The distribution of cash will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. The depositary bank will hold any cash amounts it is unable to distribute in a non-interest bearing account for the benefit of the applicable holders and beneficial owners of ADSs until the distribution can be effected or the funds that the depositary bank holds must be escheated as unclaimed property in accordance with the laws of the relevant states of the United States.

Distributions of Shares

Whenever we make a free distribution of ordinary shares for the securities on deposit with the Custodian, we will deposit the applicable number of ordinary shares with the Custodian. Upon receipt of confirmation of such deposit, the depositary bank will either distribute to holders new ADSs representing the ordinary shares deposited or modify the ADS-to-ordinary share ratio, in which case each ADS you hold will represent rights and interests in an integral number of the additional ordinary shares so deposited. Only whole new ADSs will be distributed. Fractional entitlements will be sold and the proceeds of such sale will be distributed as in the case of a cash distribution.

The distribution of new ADSs or the modification of the ADS-to-ordinary share ratio upon a distribution of ordinary shares will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes or governmental charges, the depositary bank may sell all or a portion of the new ordinary shares so distributed.

No such distribution of new ADSs will be made if it would violate a law (i.e., the U.S. securities laws) or if it is not practicable. If the depositary bank does not distribute new ADSs as described above, it may sell the ordinary shares received upon the terms described in the deposit agreement and will distribute the proceeds of the sale as in the case of a distribution of cash.

Distributions of Rights

Whenever we intend to distribute rights to purchase additional ordinary shares, we will give prior notice to the depositary bank and will indicate whether we wish the elective distribution to be made available to you. In such case, we will assist the depositary bank in determining whether such distribution is lawful and whether it is reasonably practicable to distribute rights to purchase additional ADSs to holders.

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The depositary bank will establish procedures to distribute rights to purchase additional ADSs to holders and to enable such holders to exercise such rights if it is lawful and reasonably practicable to make the rights available to holders of ADSs, we indicate that we wish such rights to be made available to holders of ADSs, and if we provide all of the documentation contemplated in the deposit agreement (such as opinions to address the lawfulness of the transaction). You may have to pay fees, expenses, taxes and other governmental charges to subscribe for the new ADSs upon the exercise of your rights. The depositary bank is not obligated to establish procedures to facilitate the distribution and exercise by holders of rights to purchase new ordinary shares other than in the form of ADSs.

The depositary bank will not distribute the rights to you if:

•

We do not timely request that the rights be distributed to you or we request that the rights not be distributed to you; or

•

We fail to deliver satisfactory documents to the depositary bank; or

•

It is not reasonably practicable to distribute the rights.

The depositary bank will sell the rights that are not exercised or not distributed if such sale is lawful and reasonably practicable. The proceeds of such sale will be distributed to holders as in the case of a cash distribution. If the depositary bank is unable to sell the rights, it will allow the rights to lapse.

Elective Distributions

Whenever we intend to distribute a dividend payable at the election of shareholders either in cash or in additional shares, we will give prior notice thereof to the depositary bank and will indicate whether we wish the elective distribution to be made available to you. In such case, we will assist the depositary bank in determining whether such distribution is lawful and reasonably practicable.

The depositary bank will make the election available to you only if it is lawful and reasonably practicable, we indicate that we wish such election to be made available to holders of ADSs, and if we have provided all of the documentation contemplated in the deposit agreement. In such case, the depositary bank will establish procedures to enable you to elect to receive either cash or additional ADSs, in each case as described in the deposit agreement.

If the election is not made available to you, you will receive either cash or additional ADSs, upon the terms described above for distributions of cash and ordinary shares, respectively, depending on what a shareholder in England and Wales would receive upon failing to make an election, as more fully described in the deposit agreement.

Other Distributions

Whenever we intend to distribute property other than cash, ordinary shares or rights to purchase additional ordinary shares, we will notify the depositary bank in advance and will indicate whether we wish such distribution to be made to you. If so, we will assist the depositary bank in determining whether such distribution to holders is lawful and reasonably practicable.

If it is reasonably practicable to distribute such property to you, we indicate that we wish such distribution to be made available to holders of ADSs, and if we provide all of the documentation contemplated in the deposit agreement, the depositary bank will distribute the property to the holders in a manner it deems practicable.

The distribution will be made net of fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes and governmental charges, the depositary bank may sell all or a portion of the property received.

The depositary bank will not distribute the property to you and will sell the property if:

•

We do not request that the property be distributed to you or if we ask that the property not be distributed to you; or

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•

We do not deliver satisfactory documents to the depositary bank; or

•

The depositary bank determines that all or a portion of the distribution to you is not reasonably practicable.

The proceeds of such a sale will be distributed to holders as in the case of a cash distribution.

Redemption

Whenever we decide to redeem any of the securities on deposit with the Custodian, we will notify the depositary bank in advance. If it is practicable and if we provide all of the documentation contemplated in the deposit agreement, the depositary bank will provide notice of the redemption to the holders.

The Custodian will be instructed to surrender the shares being redeemed against payment of the applicable redemption price. The depositary bank will convert the redemption funds received into U.S. dollars upon the terms of the deposit agreement and will establish procedures to enable holders to receive the net proceeds from the redemption upon surrender of their ADSs to the depositary bank.

You may have to pay fees, expenses, taxes and other governmental charges upon the redemption of your ADSs. If less than all ADSs are being redeemed, the ADSs to be retired will be selected by lot or on a pro rata basis, as the depositary bank may determine.

Changes Affecting Ordinary Shares

The ordinary shares held on deposit for your ADSs may change from time to time. For example, there may be a change in nominal or par value, a split-up, cancellation, consolidation or any other reclassification of such ordinary shares or a recapitalization, reorganization, merger, consolidation or sale of assets of the Company.

If any such change were to occur, your ADSs would, to the extent permitted by law, represent the right to receive the property received or exchanged in respect of the ordinary shares held on deposit. The depositary bank may in such circumstances deliver new ADSs to you, amend the deposit agreement, the ADRs and the applicable Registration Statement(s) on Form F-6, call for the exchange of your existing ADSs for new ADSs and take any other actions that are appropriate to reflect as to the ADSs the change affecting the Shares. If the depositary bank may not lawfully distribute such property to you, the depositary bank may sell such property and distribute the net proceeds to you as in the case of a cash distribution.

Issuance of ADSs upon Deposit of Ordinary Shares

After the completion of this offering, the ordinary shares that underlie the ADSs that are being offered for sale pursuant to this prospectus will be deposited by us with the Custodian. Upon receipt of confirmation of such deposit, the depositary bank will issue ADSs to the underwriters named in any applicable prospectus supplement.

After the closing of this offer, the depositary bank may create ADSs on your behalf if you or your broker deposit ordinary shares with the Custodian. The depositary bank will deliver these ADSs to the person you indicate only after you pay any applicable issuance fees and any charges and taxes payable for the transfer of the ordinary shares to the Custodian. Your ability to deposit ordinary shares and receive ADSs may be limited by U.S. and English legal considerations applicable at the time of deposit.

The issuance of ADSs may be delayed until the depositary bank or the Custodian receives confirmation that all required approvals have been given and that the ordinary shares have been duly transferred to the Custodian. The depositary bank will only issue ADSs in whole numbers.

When you make a deposit of ordinary shares, you will be responsible for transferring good and valid title to the depositary bank. As such, you will be deemed to represent and warrant that:

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The ordinary shares are duly authorized, validly issued, fully paid, non-assessable and legally obtained.

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All preemptive (and similar) rights, if any, with respect to such ordinary shares have been validly waived or exercised.

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You are duly authorized to deposit the ordinary shares.

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The ordinary shares presented for deposit are free and clear of any lien, encumbrance, security interest, charge, mortgage or adverse claim, and are not, and the ADSs issuable upon such deposit will not be, “restricted securities” (as defined in the deposit agreement).

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The ordinary shares presented for deposit have not been stripped of any rights or entitlements.

If any of the representations or warranties are incorrect in any way, we and the depositary bank may, at your cost and expense, take any and all actions necessary to correct the consequences of the misrepresentations.

Transfer, Combination and Split Up of ADRs

As an ADR holder, you will be entitled to transfer, combine or split up your ADRs and the ADSs evidenced thereby. For transfers of ADRs, you will have to surrender the ADRs to be transferred to the depositary bank and also must:

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ensure that the surrendered ADR is properly endorsed or otherwise in proper form for transfer;

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provide such proof of identity and genuineness of signatures as the depositary bank deems appropriate;

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provide any transfer stamps required by the State of New York or the United States; and

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pay all applicable fees, charges, expenses, taxes and other government charges payable by ADR holders pursuant to the terms of the deposit agreement, upon the transfer of ADRs.

To have your ADRs either combined or split up, you must surrender the ADRs in question to the depositary bank with your request to have them combined or split up, and you must pay all applicable fees, charges and expenses payable by ADR holders, pursuant to the terms of the deposit agreement, upon a combination or split up of ADRs.

Withdrawal of Ordinary Shares Upon Cancellation of ADSs

As a holder, you will be entitled to present your ADSs to the depositary bank for cancellation and then receive the corresponding number of underlying ordinary shares at the Custodian’s offices. Your ability to withdraw the ordinary shares held in respect of the ADSs may be limited by U.S. and English considerations applicable at the time of withdrawal. In order to withdraw the ordinary shares represented by your ADSs, you will be required to pay to the depositary bank the fees for cancellation of ADSs and any charges and taxes payable upon the transfer of the ordinary shares being withdrawn. You assume the risk for delivery of all funds and securities upon withdrawal. Once canceled, the ADSs will not have any rights under the deposit agreement.

The depositary bank may ask you to provide proof of identity and genuineness of any signature and such other documents as the depositary bank may deem appropriate before it will cancel your ADSs. The withdrawal of the ordinary shares represented by your ADSs may be delayed until the depositary bank receives satisfactory evidence of compliance with all applicable laws and regulations. Please keep in mind that the depositary bank will only accept ADSs for cancellation that represent a whole number of securities on deposit.

You will have the right to withdraw the securities represented by your ADSs at any time except for:

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Temporary delays that may arise because (i) the transfer books for the ordinary shares or ADSs are closed, or (ii) ordinary shares are immobilized on account of a shareholders’ meeting or a payment of dividends;

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Obligations to pay fees, taxes and similar charges; and

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Restrictions imposed because of laws or regulations applicable to ADSs or the withdrawal of securities on deposit.

The deposit agreement may not be modified to impair your right to withdraw the securities represented by your ADSs except to comply with mandatory provisions of law.

Voting Rights

As a holder, you generally have the right under the deposit agreement to instruct the depositary bank to exercise the voting rights for the ordinary shares represented by your ADSs. The voting rights of holders of ordinary shares are described in “Description of Share Capital — Key Provisions of Our Articles of Association — Shares and Rights Attaching to Them — Voting Rights.”

At our request, the depositary bank will distribute to you any notices of shareholders’ meetings received from us together with information explaining how to instruct the depositary bank to exercise the voting rights of the securities represented by ADSs.

If the depositary bank timely receives voting instructions from a holder of ADSs, it will endeavor to vote the securities (in person or by proxy) represented by the holder’s ADSs in accordance with the voting instructions received from such holder and as follows.

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In the event of voting by show of hands, the Depositary will vote (or cause the Custodian to vote) all Shares held on deposit at that time in accordance with the voting instructions received from a majority of holders of ADSs who provide timely voting instructions.

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In the event of voting by poll, the Depositary will vote (or cause the Custodian to vote) the Shares held on deposit in accordance with the voting instructions received from the holders of ADSs. Under certain limited circumstances described in the deposit agreement, a person designated by us shall be entitled to vote the Shares held on deposit for which voting instructions have not been timely received by the depositary from holders of ADSs.

Securities for which no voting instructions have been received will not be voted (except as otherwise contemplated herein). Please note that the ability of the depositary bank to carry out voting instructions may be limited by practical and legal limitations and the terms of the securities on deposit. We cannot assure you that you will receive voting materials in time to enable you to return voting instructions to the depositary bank in a timely manner.

Fees and Charges

As an ADS holder, you will be required to pay the following fees under the terms of the deposit agreement:

	Service			Fees
	Issuance of ADSs (excluding issuances as a result of distributions of ordinary shares)			Up to U.S. 5¢ per ADS issued
	Cancellation of ADSs			Up to U.S. 5¢ per ADS canceled
	Distribution of cash dividends or other cash distributions (i.e., sale of rights and other entitlements)			Up to U.S. 5¢ per ADS held
	Distribution of ADSs pursuant to stock dividends, free stock distributions or exercise of rights to purchase additional ADSs			Up to U.S. 5¢ per ADS held
	Distribution of securities other than ADSs or rights to purchase additional ADSs (i.e., spin-off ordinary shares)			Up to U.S. 5¢ per ADS held
	Depositary Services			Up to U.S. 5¢ per ADS held on the applicable record date(s) established by the depositary bank

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As an ADS holder you will also be responsible for paying certain fees and expenses incurred by the depositary bank and certain taxes and governmental charges such as:

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Fees for the transfer and registration of Shares or other deposited securities to or from the Custodian, the depositary bank or any nominees, including those charged by the share registrar and transfer agent for the Shares in England and Wales (i.e., upon deposit and withdrawal of Shares).

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Expenses and charges incurred by the depositary bank for converting foreign currency into U.S. dollars.

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Expenses for cable, telex and fax transmissions and for delivery of securities.

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Taxes and duties (including applicable interest and penalties) and other governmental charges, including upon the transfer of securities (i.e., when Shares are deposited or withdrawn from deposit).

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Fees and expenses as are incurred by the depositary bank in connection with compliance with exchange control regulations and other regulatory requirements applicable to Shares, deposited securities, ADSs and ADRs.

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Fees and expenses incurred by the depositary bank, the Custodian, or any nominee in connection with the delivery or servicing of Shares and other property on deposit.

Depositary fees payable upon the issuance and cancellation of ADSs are typically paid to the depositary bank by the brokers (on behalf of their clients) receiving the newly issued ADSs from the depositary bank and by the brokers (on behalf of their clients) delivering the ADSs to the depositary bank for cancellation. The brokers in turn charge these fees to their clients. Depositary fees payable in connection with distributions of cash or securities to ADS holders and the depositary services fee are charged by the depositary bank to the holders of record of ADSs as of the applicable ADS record date.

The Depositary fees payable for cash distributions are generally deducted from the cash being distributed. In the case of distributions other than cash (i.e., stock dividend, rights), the depositary bank charges the applicable fee to the ADS record date holders concurrent with the distribution or may deduct such fees and charges from distributions made to Holders. In the case of ADSs registered in the name of the investor (whether certificated or uncertificated in direct registration), the depositary bank sends invoices to the applicable record date ADS holders. In the case of ADSs held in brokerage and custodian accounts (via DTC), the depositary bank generally collects its fees through the systems provided by DTC (whose nominee is the registered holder of the ADSs held in DTC) from the brokers and custodians holding ADSs in their DTC accounts. The brokers and custodians who hold their clients’ ADSs in DTC accounts in turn charge their clients’ accounts the amount of the fees paid to the depositary bank.

In the event of a refusal to pay the depositary fees, the depositary bank may, under the terms of the deposit agreement, refuse the requested service until payment is received or may set off the amount of the depositary fees from any distribution to be made to the ADS holder. Certain ADS fees and charges such as the ADS service fee may become payable shortly after the closing of this offering.

Note that the fees and charges you may be required to pay may vary over time and may be changed by us and by the depositary bank. You will receive prior notice of such changes.

The depositary bank may reimburse us for certain expenses incurred by us in respect of the ADR program established pursuant to the deposit agreement, by making available a portion of the depositary fees charged in respect of the ADR program or otherwise, upon such terms and conditions as we and the depositary bank may agree from time to time.

Amendments and Termination

We may agree with the depositary bank to modify the deposit agreement at any time without your consent. We undertake to give holders 30 days’ prior notice of any modifications that would materially prejudice any of their substantial rights under the deposit agreement. We will not consider to be materially prejudicial to your substantial rights any modifications or supplements that are reasonably necessary for the ADSs to be registered under the Securities Act or to be eligible for book-entry settlement, in each case without imposing or increasing the fees and charges you are required to pay. In addition, we may not be

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able to provide you with prior notice of any modifications or supplements that are required to accommodate compliance with applicable provisions of law.

You will be bound by the modifications to the deposit agreement if you continue to hold your ADSs after the modifications to the deposit agreement become effective. The deposit agreement cannot be amended to prevent you from withdrawing the ordinary shares represented by your ADSs (except as permitted by law).

We have the right to direct the depositary bank to terminate the deposit agreement. Similarly, the depositary bank may in certain circumstances on its own initiative terminate the deposit agreement. In either case, the depositary bank must give notice to the holders at least 30 days before termination. Until termination, your rights under the deposit agreement will be unaffected.

After termination, the depositary bank will continue to collect distributions received (but will not distribute any such property until you request the cancellation of your ADSs) and may sell the securities held on deposit. After the sale, the depositary bank will hold the proceeds from such sale and any other funds then held for the holders of ADSs in a non-interest bearing account. At that point, the depositary bank will have no further obligations to holders other than to account for the funds then held for the holders of ADSs still outstanding (after deduction of applicable fees, taxes and expenses).

Books of Depositary

The depositary bank will maintain ADS holder records at its depositary office. You may inspect such records at such office during regular business hours but solely for the purpose of communicating with other holders in the interest of business matters relating to the ADSs and the deposit agreement.

The depositary bank will maintain in New York facilities to record and process the issuance, cancellation, combination, split-up and transfer of ADSs. These facilities may be closed from time to time, to the extent not prohibited by law.

Limitations on Obligations and Liabilities

The deposit agreement limits our obligations and the depositary bank’s obligations to you. Please note the following:

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We and the depositary bank are obligated only to take the actions specifically stated in the deposit agreement without negligence or bad faith.

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The depositary bank disclaims any liability for any failure to carry out voting instructions, for any manner in which a vote is cast or for the effect of any vote, provided it acts in good faith and in accordance with the terms of the deposit agreement.

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The depositary bank disclaims any liability for any failure to determine the lawfulness or practicality of any action, for the content of any document forwarded to you on our behalf or for the accuracy of any translation of such a document, for the investment risks associated with investing in ordinary shares, for the validity or worth of the ordinary shares, for any tax consequences that result from the ownership of ADSs, for the credit-worthiness of any third party, for allowing any rights to lapse under the terms of the deposit agreement, for the timeliness of any of our notices or for our failure to give notice.

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We and the depositary bank will not be obligated to perform any act that is inconsistent with the terms of the deposit agreement.

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We and the depositary bank disclaim any liability if we or the depositary bank are prevented or forbidden from or subject to any civil or criminal penalty or restraint on account of, or delayed in, doing or performing any act or thing required by the terms of the deposit agreement, by reason of any provision, present or future of any law or regulation, or by reason of present or future provision of any provision of our articles of association or any provision of or governing the securities on deposit, or by reason of any act of God or war or other circumstances beyond our control.

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We and the depositary bank disclaim any liability by reason of any exercise of, or failure to exercise, any discretion provided for in the deposit agreement or in our articles of association or in any provisions of or governing the securities on deposit.

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We and the depositary bank further disclaim any liability for any action or inaction in reliance on the advice or information received from legal counsel, accountants, any person presenting Shares for deposit, any holder of ADSs or authorized representatives thereof, or any other person believed by either of us in good faith to be competent to give such advice or information.

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We and the depositary bank also disclaim liability for the inability by a holder to benefit from any distribution, offering, right or other benefit that is made available to holders of ordinary shares but is not, under the terms of the deposit agreement, made available to you.

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We and the depositary bank may rely without any liability upon any written notice, request or other document believed to be genuine and to have been signed or presented by the proper parties.

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We and the depositary bank also disclaim liability for any consequential or punitive damages for any breach of the terms of the deposit agreement.

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No disclaimer of any Securities Act liability is intended by any provision of the deposit agreement.

Taxes

A Holder will be responsible for the taxes and other governmental charges payable on the ADSs and the securities represented by the ADSs. We, the depositary bank and the Custodian may deduct from any distribution the taxes and governmental charges payable by holders and may sell any and all property on deposit to pay the taxes and governmental charges payable by holders. You will be liable for any deficiency if the sale proceeds do not cover the taxes that are due.

The depositary bank may refuse to issue ADSs, to deliver, transfer, split-up or combine ADRs or to release securities on deposit until all taxes and charges are paid by the applicable holder. The depositary bank and the Custodian may take reasonable administrative actions to obtain tax refunds and reduced tax withholding for any distributions on your behalf. However, you may be required to provide to the depositary bank and to the Custodian proof of taxpayer status and residence and such other information as the depositary bank and the Custodian may require to fulfill legal obligations. You are required to indemnify us, the depositary bank and the Custodian for any claims with respect to taxes based on any tax benefit obtained for you.

Foreign Currency Conversion

The depositary bank will arrange for the conversion of all foreign currency received into U.S. dollars if such conversion is practical, and it will distribute the U.S. dollars in accordance with the terms of the deposit agreement. You may have to pay fees and expenses incurred in converting foreign currency, such as fees and expenses incurred in complying with currency exchange controls and other governmental requirements.

If the conversion of foreign currency is not practicable or lawful, or if any required approvals are denied or not obtainable at a reasonable cost or within a reasonable period, the depositary bank may take the following actions in its discretion:

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Convert the foreign currency to the extent practical and lawful and distribute the U.S. dollars to the holders for whom the conversion and distribution is lawful and practical.

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Distribute the foreign currency to holders for whom the distribution is lawful and practical.

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Hold the foreign currency (without liability for interest) for the applicable holders.

Governing Law/Waiver of Jury Trial

The deposit agreement, the ADRs and the ADSs will be interpreted in accordance with the laws of the State of New York. The rights of holders of ordinary shares (including ordinary shares represented by ADSs) are governed by the laws of England and Wales. As an owner of ADSs, holders irrevocably agree that any legal action arising out of the Deposit Agreement, the ADSs or the ADRs, involving the Company or the Depositary, may only be instituted in a state or federal court in the city of New York.

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DESCRIPTION OF WARRANTS

We may issue, separately or together with other securities, warrants to purchase ordinary shares, including ordinary shares represented by ADSs. Each series of warrants will be issued under a separate warrant agreement, the terms of which will be described in the applicable prospectus supplement.

The following summary of the terms of the warrants does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the terms of the warrants as well as the form of warrant agreement and the terms of the applicable underlying securities. Therefore, you should carefully consider the actual provisions of those documents.

The particular terms of any issue of warrants will be described in the prospectus supplement relating to the issue. Those terms may include:

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the title of such warrants;

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the aggregate number of such warrants;

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the price or prices at which such warrants will be issued;

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the date on which the right to exercise such warrants shall commence and the date on which such right shall expire;

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if applicable, the minimum or maximum amount of such warrants which may be exercised at any one time;

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if applicable, the date on and after which such warrants and the related securities will be separately transferable;

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information with respect to book-entry procedures, if any;

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if applicable, a discussion of any material U.S. federal income tax and material U.K. tax considerations relevant to such warrants; and

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any other terms of such warrants, including terms, procedures and limitations relating to the exchange and exercise of such warrants.

We urge you to read the prospectus supplement related to any series of warrants we may offer, as well as the complete warrant agreement and warrant certificate that contain the terms of the warrants.

If we offer warrants, the forms of warrant agreements and warrant certificates relating to warrants for the purchase of such ordinary shares, including ADSs representing ordinary shares, will be incorporated by reference into the registration statement of which this prospectus is a part from reports we would subsequently file with the SEC.

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DESCRIPTION OF UNITS

We may issue units comprised of one or more of the other securities described in this prospectus or any prospectus supplement in any combination. Each unit will be issued so that the holder of the unit is also the holder, with the rights and obligations of a holder, of each security included in the unit. The units may be issued under unit agreements to be entered into between us and a unit agent, which may provide that the securities included in the unit may not be held or transferred separately, at any time or any times before a specified date or upon the occurrence of a specified event or occurrence.

The applicable prospectus supplement may describe:

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the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

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any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units;

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the terms of the unit agreement governing the units;

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United States federal income tax and material U.K. tax considerations relevant to the units; and

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whether the units will be issued in fully registered global form.

This summary of certain general terms of units and any summary description of units in the applicable prospectus supplement do not purport to be complete and are qualified in their entirety by reference to all provisions of the applicable unit agreement and, if applicable, collateral arrangements and depositary arrangements relating to such units. The forms of the unit agreements and other documents relating to a particular issue of units will be filed with the SEC each time we issue units, and you should read those documents for provisions that may be important to you.

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PLAN OF DISTRIBUTION

We may sell securities:

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through underwriters;

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through agents;

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through dealers;

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directly to purchasers; or

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through a combination of any of these methods of sale.

In addition, we may issue the securities as a dividend or distribution to our existing security holders.

This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. We will, in the prospectus supplement relating to such offering, name any agent that could be viewed as an underwriter under the Securities Act, and describe any commissions that we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis.

The distribution of the securities may be effected from time to time in one or more transactions:

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at a fixed price, or prices, which may be changed from time to time;

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at market prices prevailing at the time of sale;

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at prices relating to such market prices; or

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at negotiated prices.

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

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the name of the agent or any underwriters;

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the public offering or purchase price and the proceeds we will receive from the sale of the securities;

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any discounts and commissions to be allowed or re-allowed or paid to the agent or underwriters;

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all other items constituting underwriting compensation;

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any discounts and commissions to be allowed or re-allowed or paid to dealers; and

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any exchanges on which the securities will be listed.

If any underwriters or agents are utilized in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

If a dealer is utilized in the sale of the securities in respect of which this prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

Agents, underwriters, dealers and other persons may be entitled under agreements which they may enter into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

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In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may overallot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in one business day, unless the parties to any such trade expressly agree otherwise or the securities are sold by us to an underwriter in a firm commitment underwritten offering. The applicable prospectus supplement may provide that the original issue date for your securities may be more than one scheduled business day after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the first business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than one scheduled business day after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.

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SERVICE OF PROCESS AND ENFORCEMENT OF JUDGMENTS

We are incorporated under the laws of England and Wales. Some of our directors and officers reside outside the United States, and a substantial portion of our assets and all or a substantial portion of the assets of such persons are located outside the United States. As a result, it may be difficult for you to serve legal process on us or our directors and executive officers (as well as certain directors, managers and executive officers of our subsidiaries) or have any of them appear in a United States court.

We have appointed Adaptimmune LLC as our authorized agent upon whom process may be served in any action instituted in any U.S. federal or state court having subject matter jurisdiction in the Borough of Manhattan in New York, New York, arising out of or based upon the ADSs, the deposit agreement or the underwriting agreement related to such ADSs.

Mayer Brown International LLP, our English counsel, has advised us that there is some doubt as to the enforceability in the United Kingdom, in original actions or in actions for enforcement of judgments of U.S. courts, of civil liabilities based solely on the federal securities laws of the United States. In addition, awards for punitive damages in actions brought in the United States or elsewhere may be unenforceable in the United Kingdom. An award for monetary damages under the U.S. securities laws would be considered punitive if it does not seek to compensate the claimant for loss or damage suffered and is intended to punish the defendant. The enforceability of any judgment in the United Kingdom will depend on the particular facts of the case as well as the laws and treaties in effect at the time. The United States and the United Kingdom do not currently have a treaty providing for recognition and enforcement of judgments (other than arbitration awards) in civil and commercial matters.

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The information in this prospectus supplement is not complete and may be changed. We may not sell these securities 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 we are not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

PROSPECTUS SUPPLEMENT Subject to completion, dated April 18, 2025

$200,000,000

American Depositary Shares representing Ordinary Shares

We have entered into an amendment on April 18, 2025 to our sales agreement with TD Securities (USA) LLC (“TD Cowen”), dated April 8, 2022, relating to the sale of our American Depositary Shares (“ADSs”), offered by this prospectus supplement (the “Amended Sales Agreement”). In accordance with the terms of the Amended Sales Agreement, under this prospectus supplement we may offer and sell our ADSs, each of which represents six ordinary shares, nominal value £0.001 per share, having an aggregate offering price of up to $200,000,000 from time to time through TD Cowen, acting as our agent or principal.

The Amended Sales Agreement amends our sales agreement, dated April 8, 2022, with TD Cowen (as successor to Cowen and Company, LLC) (the “Original Sales Agreement”). On April 8, 2022, the Company filed a sales agreement prospectus supplement (the “Original Sales Agreement Prospectus”) covering the offering, issuance and sale of up to a maximum aggregate offering price of $200,000,000 of ADSs pursuant to the Original Sales Agreement. As of the date of this prospectus supplement, $154,719,192 ADSs remained available for sale under the Original Sales Agreement Prospectus. Upon effectiveness of the registration statement of which this prospectus supplement forms a part, the remaining $154,719,192 ADSs available for sale under the Original Sales Agreement Prospectus is included in the amount offered for sale under this prospectus supplement and no further sales will be made pursuant to the Original Sales Agreement Prospectus.

Our ADSs trade on The Nasdaq Global Select Market under the symbol “ADAP.” On April 17, 2025, the last sale price of our ADSs as reported on The Nasdaq Global Select Market was $0.23 per ADS.

Sales of our ADSs, if any, under this prospectus supplement will be made in negotiated transactions, including block trades or block sales, or by any method permitted that is deemed an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act including without limitation sales made through Nasdaq or on any other existing trading market for the ADSs, or by any other method permitted by law. TD Cowen 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 any escrow, trust or similar arrangement.

Under the sales agreement, we may also sell our ADSs to TD Cowen as principal for its own account, at a price to be agreed upon at the time of sale. If we sell ADSs to TD Cowen as principal, we will enter into a separate terms agreement with TD Cowen, and we will describe the agreement in a separate prospectus supplement or pricing supplement.

TD Cowen will be entitled to compensation at a commission rate of up to 3.0% of the gross sales price per ADS sold under the sales agreement. See “Plan of Distribution” beginning on page S-7 for additional information regarding the compensation to be paid to TD Cowen.

In connection with the sale of the ADSs on our behalf, TD Cowen will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of TD Cowen will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to TD Cowen with respect to certain liabilities, including liabilities under the Securities Act.

Investing in our ADSs involves risks. These risks are described under the caption “Risk Factors” beginning on page S-3 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement. Any representation to the contrary is a criminal offense.

TD Cowen

, 2025

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ABOUT THIS PROSPECTUS

This document consists of two parts. The first part is the accompanying prospectus, which is part of a registration statement that we filed with the SEC using a “shelf” registration process. The second part is this prospectus supplement, which describes the specific terms of this offering. The accompanying prospectus describes more general information, some of which may not apply to this offering. Under this shelf registration process, we may from time to time sell our ADSs having an aggregate offering price of up to $200,000,000 under this prospectus supplement at prices and on terms to be determined by market conditions at the time of the offering. Before buying any of the ADSs that we are offering, we urge you to carefully read both this prospectus supplement and the accompanying prospectus together with all of the information incorporated by reference herein, as well as the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.” These documents contain important information that you should consider when making your investment decision.

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.

You should rely only on the information contained in or incorporated by reference in this prospectus supplement and any related free writing prospectus filed by us with the SEC. We have not, and TD Cowen has not, authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. 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. You should assume that the information appearing in this prospectus supplement, the documents incorporated by reference and any related free writing prospectus is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed materially since those dates. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus supplement.

We are offering to sell, and seeking offers to buy, ADSs representing our ordinary shares only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the offering of the ADSs in certain jurisdictions may be restricted by law. 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 ADSs and the distribution of this prospectus supplement outside the United States. This prospectus supplement does not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

This prospectus supplement and the information incorporated herein or therein by reference contains market data, industry statistics and other data that have been obtained or compiled from information made available by independent third parties. This prospectus supplement and the information incorporated herein or therein by reference include trademarks, service marks and trade names owned by us or other companies. Solely for convenience, we may refer to our trademarks included or incorporated by reference in this prospectus supplement or any free writing prospectus without the TM or ® symbols, but any such references are not intended to indicate that we will not assert, to the fullest extent permitted under applicable law, our rights to our trademarks or other intellectual property. All trademarks, service marks and trade names included or incorporated by reference in this prospectus supplement or any related free writing prospectus are the property of their respective owners.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights selected information contained elsewhere in this prospectus and in the documents we incorporate by reference. This summary does not contain all of the information you should consider before making an investment decision. You should read this entire prospectus supplement carefully, especially the risks of investing in our ADSs discussed under “Risk Factors” beginning on page S-3 of this prospectus supplement, along with our consolidated financial statements and notes to those consolidated financial statements and the other information incorporated by reference in this prospectus supplement.

Overview

Corporate Information

Adaptimmune Therapeutics plc was incorporated on December 3, 2014, and is a public limited company incorporated under the laws of England and Wales. Our registered and principal executive offices are located at 60 Jubilee Avenue, Milton Park, Abingdon, Oxfordshire OX14 4RX, United Kingdom, our general telephone number is (+44) 1235 430000 and our corporate website address is www.adaptimmune.com. Our website and the information contained on or accessible through our website are not part of this document. We have included our website address in this prospectus solely as an inactive textual reference. Our agent for service of process in the United States is Adaptimmune LLC, located at 351 Rouse Boulevard, The Navy Yard, Philadelphia PA 19112, United States.

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RISK FACTORS

An investment in our securities involves risks. We urge you to carefully consider all of the information contained in or incorporated by reference in this prospectus supplement as provided under “Incorporation of Certain Information by Reference,” including the risks described under “Risk Factors” in Item 1A of our most recent Annual Report on Form 10-K and in any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. This prospectus also contains forward-looking statements that involve risks and uncertainties. Please read “Special Note on Forward-Looking Statements.” Our actual results could differ materially from those anticipated in the forward-looking statements as a result of certain factors, including the risks described elsewhere in this prospectus and in the documents incorporated by reference into this prospectus. If any of these risks occur, our business, financial condition or results of operation could be adversely affected. As a result, you could lose all or part of your investment.

Risks Related to Our ADSs and this Offering

The market price and trading volume of our ADSs has been and will likely continue to be volatile.

Many factors may have a material adverse effect on the market price of the ADSs, including but not limited to:

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the commencement, enrollment or results of our planned clinical trials;

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the loss of any of our key scientific or management personnel;

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announcements of the failure to obtain regulatory approvals or receipt of a complete response letter from the FDA;

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announcements of undesirable restricted labeling indications or patient populations, or changes or delays in regulatory review processes;

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announcements of therapeutic innovations or new products by us or our competitors;

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adverse actions taken by regulatory agencies with respect to our clinical trials, manufacturing supply chain or sales and marketing activities;

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changes or developments in laws or regulations applicable to T-cells;

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any adverse changes to our relationship with licensors, manufacturers or suppliers;

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the failure of our testing and clinical trials;

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unanticipated safety concerns;

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the failure to retain our existing, or obtain new, collaboration partners;

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announcements concerning our competitors or the pharmaceutical industry in general;

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the achievement of expected product sales and profitability;

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the failure to obtain reimbursements for T-cells, if approved for marketing, or price reductions;

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manufacture, supply or distribution shortages;

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acquisitions or mergers and business deals announced by us or our competitors;

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the progress of competing treatment options and products or advent of new products which could impact the uptake or commercial value of our cell therapies;

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actual or anticipated fluctuations in our operating results;

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our cash position including any increases in our costs and expenses which could have a material impact on our ability to continue as a going concern including any requirement to repay further loan amounts prior to the stated maturity under the Loan and Security Agreement dated May 14, 2024 with Hercules Capital, Inc. through breach of covenants and obligations under the agreement or otherwise;

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changes in financial estimates or recommendations by securities analysts;

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potential acquisitions;

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the trading volume of ADSs on the Nasdaq Global Select Market (“Nasdaq”);

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sales of our ADSs by us, our executive officers and directors or our shareholders in the future;

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general economic and market conditions and overall fluctuations in the U.S. equity markets including, but not limited to, as resulting from geopolitical factors and natural disasters and economic effects of such factors; and

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changes in accounting principles.

In addition, the stock market in general, and Nasdaq and biopharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our ADSs, regardless of our actual operating performance. Further, a decline in the financial markets and related factors beyond our control may cause the price of our ADSs to decline rapidly and unexpectedly. In the past, securities class action litigation has often been instituted against companies following periods of volatility in their stock price. This type of litigation could result in substantial costs and could divert our management and other resources.

We do not anticipate paying cash dividends, and accordingly, holders of our ADSs must rely on appreciation in the price of the ADSs for any return on their investment.

We currently intend to retain our future earnings, if any, to fund the development and growth of our businesses. As a result, capital appreciation, if any, of our ADSs will be your sole source of gain on your investment for the foreseeable future. Investors seeking cash dividends should not invest in our ADSs.

If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, our ADS price and trading volume could decline.

The trading market for our ADSs depends on the research and reports that securities or industry analysts publish about us or our business. We do not have any control over these analysts. We cannot assure you that analysts will cover us or provide favorable coverage. If one or more of the analysts who cover us downgrade our ADSs or change their opinion of our ADSs, our ADS price would likely decline. If one or more of these analysts cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which could cause our ADS price or trading volume to decline.

You may not have the same voting rights as the holders of our ordinary shares and may not receive voting materials in time to be able to exercise your right to vote.

Except as described in this prospectus, holders of the ADSs will not be able to exercise voting rights attaching to the ordinary shares represented by the ADSs on an individual basis. Holders of the ADSs will appoint the depositary or its nominee as their representative to exercise the voting rights attaching to the ordinary shares represented by the ADSs. You may not receive voting materials in time to instruct the depositary to vote, and it is possible that you, or persons who hold their ADSs through brokers, dealers or other third parties, will not have the opportunity to exercise a right to vote.

You may not receive distributions on our ordinary shares represented by the ADSs or any value for them if it is unlawful or impracticable to make such distributions available to holders of ADSs.

The depositary for the ADSs has agreed to pay to you the cash dividends or other distributions it or the Custodian receives on our ordinary shares or other deposited securities after deducting its fees and expenses. You will receive these distributions in proportion to the number of our ordinary shares that your ADSs represent. However, in accordance with the limitations set forth in the deposit agreement, it may be unlawful or impracticable to make a distribution available to holders of ADSs. We have no obligation to take any other action to permit distribution on the ADSs, ordinary shares, rights or anything else to holders of the ADSs. This means that you may not receive the distributions we make on our ordinary shares or any value from them if it is unlawful or impracticable to make them available to you. These restrictions may have a material adverse effect on the value of your ADSs.

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We will have broad discretion as to the use of the proceeds from this offering, and we may not use the proceeds effectively.

We have not designated the amount of net proceeds we will use for any particular purpose.

Accordingly, our management will have broad discretion as to the application of the net proceeds and could use them for purposes other than those contemplated at the time of this offering. Our shareholders may not agree with the manner in which our management chooses to allocate and spend the net proceeds. Moreover, our management may use the net proceeds for corporate purposes that may not increase our profitability or our market value. See “Use of Proceeds” for a description of our management’s intended use of the proceeds from this offering.

The actual number of ADSs we will issue under the Amended Sales Agreement, at any one time or in total, is uncertain.

Subject to certain limitations in the Amended Sales Agreement entered into by us with TD Cowen and compliance with applicable law, we have the discretion to deliver a placement notice to TD Cowen at any time throughout the term of the sales agreement. The number of ADSs that are sold by TD Cowen after delivering a placement notice will fluctuate based on the market price of our ADSs during the sales period and limits we set with TD Cowen. Because the price per ADS sold will fluctuate based on the market price of our ADSs during the sales period, it is not possible at this stage to predict the number of ADSs that will be ultimately issued or the resulting gross proceeds.

The ADSs offered hereby will be sold in “at the market offerings,” and investors who buy shares at different times will likely pay different prices.

Investors who purchase ADSs 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 ADSs sold, and there is no minimum or maximum sales price. Investors may experience a decline in the value of their shares as a result of share sales made at prices lower than the prices they paid.

You may experience future dilution as a result of future equity offerings.

In order to raise additional capital, we may in the future offer additional ADSs at prices that may not be the same as the price per ADS in this offering. We may sell ADSs in any other offering at a price per ADS that is less than the price per ADS paid by investors in this offering. The price per ADS at which we sell additional ADSs in future transactions may be higher or lower than the price per ADS paid by investors in this offering.

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USE OF PROCEEDS

We may issue and sell our ADSs having aggregate sales proceeds of up to $200,000,000 from time to time. 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 currently intend to use the net proceeds of this offering, if any, for general corporate purposes, which may include commercialization expenses, research and development expenses, working capital and general and administrative expenses.

Our expected use of net proceeds from this offering represents our current intentions based upon our present plans and business conditions. As of the date of this prospectus supplement, we cannot predict with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering or the amounts that we will actually spend on the uses set forth above. The amounts and timing of our actual use of net proceeds will vary depending on numerous factors, including our ability to obtain additional financing, the relative success and cost of our commercialization of TECELRA, our ability to commercialize lete-cel, the relative success and cost of our research, preclinical and clinical development programs, including a change in our planned course of development or the termination of a clinical program necessitated by the results of data received from clinical trials or otherwise, the results of the our collaboration agreement with Galapagos and whether we enter into future collaborations. As a result, management will have broad discretion in the application of the net proceeds, and investors will be relying on our judgment regarding the application of the net proceeds of this offering.

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PLAN OF DISTRIBUTION

We have entered into an Amended Sales Agreement with TD Cowen relating to the sale of our ADSs, each representing six ordinary shares, through TD Cowen as our sales agent or principal. In accordance with the terms of the Amended Sales Agreement, under this prospectus supplement, we may offer and sell our ADSs having an aggregate offering price of up to $200,000,000 from time to time through TD Cowen, acting as our agent or principal. Sales of our ADSs, if any, will be made in negotiated transactions, including block trades or block sales, or at market prices by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act including without limitation sales made through Nasdaq or on any other existing trading market for the ADSs, or by any other method permitted by law. Sales pursuant to the Amended Sales Agreement may be made through an affiliate of TD Cowen.

The Amended Sales Agreement amends our sales agreement, dated April 8, 2022, with TD Cowen (as successor to Cowen and Company, LLC) (the “Original Sales Agreement”). On April 8, 2022, the Company filed a sales agreement prospectus supplement (the “Original Sales Agreement Prospectus”) covering the offering, issuance and sale of up to a maximum aggregate offering price of $200,000,000 of ADSs pursuant to the Original Sales Agreement. As of the date of this prospectus supplement, $154,719,192 of ADSs remained available for sale under the Original Sales Agreement Prospectus. Upon effectiveness of the registration statement of which this prospectus supplement forms a part, the remaining $154,719,192 ADSs available for sale under the Original Sales Agreement Prospectus is included for sale under this prospectus supplement and no further sales will be made under the Original Sales Agreement Prospectus.

TD Cowen will offer our ADSs subject to the terms and conditions of the Amended Sales Agreement on a daily basis or as otherwise agreed upon by us and TD Cowen. We will designate the maximum amount of ADSs to be sold through TD Cowen on a daily basis or otherwise determine such maximum amount together with TD Cowen.

Subject to the terms and conditions of the sales agreement, TD Cowen will use its commercially reasonable efforts to sell on our behalf all of the ADSs requested to be sold by us. We may instruct TD Cowen not to sell ADSs if the sales cannot be effected at or above the price designated by us in any such instruction. TD Cowen or we may suspend the offering of our ADSs being made through TD Cowen under the Amended Sales Agreement upon proper notice to the other party. TD Cowen and we each have the right, by giving written notice as specified in the Amended Sales Agreement, to terminate the Amended Sales Agreement in each party’s sole discretion at any time.

The aggregate compensation payable to TD Cowen as sales agent equals up to 3.0% of the gross sales price of the ADSs sold through it pursuant to the Amended Sales Agreement. We have also agreed to reimburse TD Cowen up to $75,000 of TD Cowen’s actual outside legal expenses incurred by TD Cowen in connection with this offering, and for certain other expenses, including TD Cowen’s FINRA counsel fees in an amount up to $10,000. In accordance with FINRA Rule 5110 these reimbursed fees and expenses are deemed sales compensation to TD Cowen in connection with this offering. We estimate that the total expenses of the offering payable by us, excluding commissions payable to TD Cowen under the sales agreement, will be approximately $300,000.

The remaining sales proceeds, after deducting any expenses payable by us and any transaction fees imposed by any governmental, regulatory, or self-regulatory organization in connection with the sales, will equal our net proceeds for the sale of such ADSs.

TD Cowen will provide written confirmation to us following the close of trading on The Nasdaq Global Select Market on each day in which ADSs are sold through it as sales agent under the sales agreement. Each confirmation will include the number of ADSs sold through it as sales agent on that day, the volume weighted average price of the shares sold, the percentage of the daily trading volume and the net proceeds to us.

We will report at least quarterly the number of ADSs sold through TD Cowen under the Amended Sales Agreement and the net proceeds to us in connection with the sales of ADSs.

Settlement for sales of ADSs will occur, unless the parties agree otherwise, on the first business day that is also a trading day following the date on which any sales were made in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

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Under the sales agreement, we may also sell our ADSs to TD Cowen as principal for its own account, at a price to be agreed upon at the time of sale. If we sell ADSs to a TD Cowen as principal, we will enter into a separate terms agreement with TD Cowen, and we will describe the agreement in a separate prospectus supplement or pricing supplement.

In connection with the sales of our ADSs on our behalf, TD Cowen will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation paid to TD Cowen may be deemed to be underwriting commissions or discounts. We have agreed in the Amended Sales Agreement to provide indemnification and contribution to TD Cowen against certain liabilities, including liabilities under the Securities Act. As sales agent, TD Cowen will not engage in any transactions that stabilizes our ADSs.

Our ADSs are listed on The Nasdaq Global Select Market and trade under the symbol “ADAP.” The depositary bank of our ADSs is Citibank, N.A.

TD Cowen and/or its affiliates have provided, and may in the future provide, various investment banking and other financial services for us for which services they have received and, may in the future receive, customary fees.

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TAXATION

Material U.S. Federal Income Tax Consequences

The following discussion describes the material U.S. federal income tax consequences to U.S. Holders (as defined below) under present law of the purchase, ownership and disposition of the ADSs acquired pursuant to this offering. This discussion is based on the U.S. Internal Revenue Code of 1986, as amended (or the “Code”), in effect as of the date of this prospectus supplement and on U.S. Treasury regulations in effect or, in some cases, proposed, as of the date of this prospectus supplement, as well as judicial and administrative interpretations thereof available on or before such date. All of the foregoing authorities are subject to change, which change could apply retroactively and could affect the tax consequences described below.

This discussion applies only to U.S. Holders that hold the ADSs as capital assets for U.S. federal income tax purposes. It does not purport to be a comprehensive description of all tax considerations that may be relevant to a decision to purchase the ADSs by any particular investor. In particular, this discussion does not address tax considerations applicable to a U.S. Holder that may be subject to special tax rules, including, without limitation, a dealer in securities or currencies, a trader in securities that elects to use a mark-to-market method of accounting for securities holdings, banks, or other financial institutions, an insurance company, a tax exempt organization, a person that holds the ADSs as part of a hedge, straddle or conversion transaction for tax purposes, a person whose functional currency for tax purposes is not the U.S. dollar, certain former citizens or residents of the United States or a person that owns or is deemed to own 10% or more of the company’s shares by vote or value. Moreover, this description does not address the U.S. federal estate, gift, or alternative minimum tax consequences, the special tax accounting rules under Section 451(b) of the Code, any Medicare contribution tax considerations, or any state, local or non-U.S. tax consequences, of the acquisition, ownership and disposition of the ADSs. In addition, the discussion does not address tax consequences to an entity or arrangement treated as a partnership for U.S. federal income tax purposes that holds the ADSs, or a partner in such partnership. The U.S. federal income tax treatment of each partner of such partnership generally will depend upon the status of the partner and the activities of the partnership. Prospective purchasers that are partners in a partnership holding the ADSs are urged to consult their own tax advisers.

The discussion below of the U.S. federal income tax consequences to “U.S. Holders” will apply to an investor that is a beneficial owner of ADSs and that is, for U.S. federal income tax purposes,

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an individual who is a citizen or resident of the United States;

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a corporation (or other entity taxable as a corporation for U.S. federal income tax purposes) organized under the laws of the United States, any state therein or the District of Columbia;

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an estate whose income is subject to U.S. federal income taxation regardless of its source; or

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a trust that (i) is subject to the primary supervision of a court within the United States and subject to the control of one or more U.S. persons for all substantial decisions or (ii) has a valid election in effect under applicable U.S. Treasury regulations to be treated as a U.S. person.

For U.S. federal income tax purposes, a beneficial owner of ADSs generally will be treated as the owner of the underlying ordinary shares represented by such ADSs. Accordingly, an exchange by a U.S. Holder of the ADSs for the underlying shares represented by such ADSs generally will not be subject to U.S. federal income tax.

Prospective purchasers are urged to consult their tax advisors about the application of the U.S. federal income tax rules to their particular circumstances as well as the state, local, non-U.S. and other tax consequences to them of the purchase, ownership and disposition of the ADSs.

Taxation of Dividends and Other Distributions on the ADSs

Subject to the PFIC rules discussed below, the gross amount of distributions made by us to a U.S. Holder with respect to the ADSs, before reduction for any non-U.S. taxes withheld therefrom, will be includable in gross income as dividend income to the extent that such distribution is paid out of our current

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or accumulated earnings and profits (as determined under U.S. federal income tax principles). To the extent, if any, that the amount of any distribution exceeds our current and accumulated earnings and profits, it will be treated first as a tax-free return of such U.S. Holder’s tax basis in its ADSs, and to the extent the amount of the distribution exceeds such U.S. Holder’s tax basis, the excess will be taxed as capital gain. We do not intend to calculate our earnings and profits under U.S. federal income tax principles. Therefore, a U.S. Holder should expect that a distribution will generally be reported as a dividend even if that distribution would otherwise be treated as a non-taxable return of capital or as capital gain under the rules described above. A dividend in respect of the ADSs will not generally be eligible for the dividends-received deduction allowed to corporations in respect of dividends received from other U.S. corporations.

Non-corporate U.S. Holders may qualify for the lower rates of taxation with respect to dividends on ADSs applicable to long term capital gains (i.e., gains from the sale of capital assets held for more than one year), provided that certain conditions are met, including certain holding period requirements and the absence of certain risk reduction transactions. Moreover, such reduced rate will not apply if we are a PFIC for the taxable year in which we pay a dividend, or were a PFIC for the preceding taxable year.

If dividend payments in respect of the ADSs are made in a currency other than the U.S. dollar, the amount of the dividend distribution that a U.S. Holder must include in income will be the U.S. dollar value of the payments made in such other currency, determined at the spot U.S. dollar exchange rate on the date the dividend distribution is actually or constructively received, regardless of whether the payment is in fact converted into U.S. dollars. Generally, if the foreign currency received as a dividend is not converted into U.S. dollars on the date of actual or constructive receipt, any gain or loss resulting from currency exchange fluctuations during the period from the date the dividend payment is includible in income to the date the payment is actually converted into U.S. dollars will be treated as ordinary income or loss and will not be eligible for the special tax rate applicable to qualified dividend income. The foreign currency gain or loss generally will be income or loss from sources within the United States for foreign tax credit limitation purposes.

U.S. Holders are urged to consult their tax advisors regarding the tax consequences of receiving, converting or disposing of any non-U.S. currency, received or deemed received as dividends on our ADSs or on the sale or retirement of an ADS.

Dividends generally will constitute income from sources outside the United States, which may be relevant in calculating a U.S. Holder’s foreign tax credit limitation. Subject to certain conditions and limitations, non-U.S. tax withheld, if any, on dividends may be deducted from such U.S. Holder’s taxable income or credited against such U.S. Holder’s U.S. federal income tax liability. The limitation on foreign taxes eligible for credit is calculated separately with respect to specific classes of income. For this purpose, dividends that we distribute generally should constitute “passive category income,” or, in the case of certain U.S. Holders, “general category income.” The rules relating to the determination of the foreign tax credit are complex, and U.S. Holders are urged to consult their tax advisors to determine whether and to what extent such U.S. Holder will be entitled to a foreign tax credit.

Taxation of Dispositions of ADSs

Subject to the PFIC rules discussed below, a U.S. Holder will recognize gain or loss on any sale, exchange or other taxable disposition of an ADS in an amount equal to the difference between the amount realized (in U.S. dollars) for the ADS and such U.S. Holder’s tax basis (in U.S. dollars) in the ADS.

The gain or loss will generally be capital gain or loss. A U.S. Holder’s initial tax basis in ADSs generally will equal to the cost of such ADSs. A non-corporate U.S. Holder that has held the ADS for more than one year may be eligible for preferential tax rates. The deductibility of capital losses is subject to limitations.

Any such gain or loss generally will be treated as U.S. source income or loss for U.S. foreign tax credit limitation purposes.

Passive Foreign Investment Company Considerations

Special U.S. tax rules apply to U.S. Holders of stock in companies that are considered to be PFICs. We will be classified as a PFIC in a particular taxable year if either (i) 75% or more of our gross income for the taxable year is passive income or (ii) at least 50% of the value of our gross assets (determined on the basis

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of a quarterly average) is attributable to assets that produce passive income or are held for the production of passive income (including cash). Passive income for this purpose generally includes, among other things, certain dividends, interest, royalties and rents (other than certain rents or royalties derived in the active conduct of a trade or business), and gains from commodities and securities transactions and from the sale or exchange of property that gives rise to passive income. In making this determination, we will be treated as earning our proportionate share of any income and owning our proportionate share of any assets of any corporation in which we hold a 25% or greater interest (by value).

The determination of whether we are a PFIC depends on the particular facts and circumstances (such as the valuation of our assets, including goodwill and other intangible assets) and may also be affected by the application of the PFIC rules, which are subject to differing interpretations. In addition, it is not entirely clear how to apply the income test to a company like us, which for any particular taxable year may have gross income that is either entirely passive or that significantly exceeds any active gross income, but the overall losses of which from research and development activities exceed the overall amount of its gross income for that year. Based on our estimated gross income, the average value of our assets, including goodwill, and the nature of our active business, although not free from doubt, we do not believe that we were classified as a PFIC for U.S. federal income tax purposes for our U.S. taxable year ended December 31, 2024. There can be no assurance, however, that we will not be considered to be a PFIC for this taxable year or any particular year in the future because PFIC status is factual in nature, depends upon factors not wholly within our control, generally cannot be determined until the close of the taxable year in question and is determined annually. Our status for any taxable year will depend on our income, assets and activities in that year, and because this is a factual determination made annually after the end of each taxable year, there can be no assurance that we will not be considered a PFIC for this taxable year or any future taxable year. The market value of our assets may be determined in large part by reference to the market price of the ADSs, which is likely to fluctuate (and may fluctuate considerably given that market prices of life sciences companies can be especially volatile).

Furthermore, because the value of our gross assets is likely to be determined in large part by reference to our market capitalization and the value of our goodwill, a decline in the value of our shares could affect the determination of whether we are a PFIC. Finally, as a clinical-stage biopharmaceutical company, we may have more passive income than active income in any particular taxable year, which could affect our PFIC status under the gross income test.

A U.S. Holder may be able to mitigate some of the adverse U.S. federal income tax consequences described below with respect to owning the ADSs if we are classified as a PFIC for any taxable year, provided that such U.S. Holder is eligible to make, and validly makes a “mark-to-market” election, described below. In certain circumstances a U.S. Holder can make a “qualified electing fund” election to mitigate some of the adverse tax consequences described below with respect to an ownership interest in a PFIC by including in income its share of the PFIC’s income on a current basis. However, we do not currently intend to prepare or provide the information that would enable a U.S. Holder to make a qualified electing fund election.

In the event that we are classified as a PFIC in any year in which a U.S. Holder holds the ADSs, and the “mark-to-market” election described in the following discussion is not made by a taxable U.S. Holder, a special tax regime will apply with respect to such U.S. Holder to both (a) any gain realized on the sale or other disposition of the ADSs and (b) any “excess distribution” by us to such U.S. Holder (generally, such U.S. Holder’s ratable portion of distributions received by such U.S. Holder in any year which are greater than 125% of the average annual distribution received by such U.S. Holder in the shorter of the three preceding years or such U.S. Holder’s holding period for the ADSs). Any gain recognized by such U.S. Holder on a sale or other disposition (including a pledge) of the ADSs and any excess distribution would be allocated ratably over such U.S. Holder’s holding period for the ADSs.

The amounts allocated to the taxable year of the sale or other disposition and to any year before we became a PFIC would be taxed as ordinary income. The amount allocated to each other taxable year would be subject to tax at the highest rate in effect for individuals or corporations, as appropriate, for that taxable year, and the interest charge generally applicable to underpayments of tax would be imposed on

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taxes deemed to have been payable in for the relevant taxable PFIC years. Classification as a PFIC may also have other adverse tax consequences, including the inability to obtain preferential rates of taxation on dividends, as described above.

Mark-to-Market Election

If we are a PFIC for any taxable year during which a U.S. Holder holds the ADSs, then in lieu of being subject to the special tax regime and interest charge rules discussed above, a U.S. Holder may make an election to include gain on the ADSs as ordinary income under a mark-to-market method, provided that such ADSs are treated as “regularly traded” on a “qualified exchange.” In general, the ADSs will be treated as “regularly traded” for a given calendar year if more than a de minimis quantity of the ADSs are traded on a qualified exchange on at least 15 days during each calendar quarter of such calendar year. The ADSs are listed on the Nasdaq Global Select Market, which is a qualified exchange; however, no assurance can be given that the ADSs will meet the requirements to be treated as “regularly traded” for purposes of the mark-to-market election. In addition, because a mark-to-market election cannot be made for any lower-tier PFICs that we may own, a U.S. Holder may continue to be subject to the special tax regime with respect to such holder’s indirect interest in any investments held by us that are treated as an equity interest in a PFIC for U.S. federal income tax purposes, including shares in any future subsidiary of ours that is treated as a PFIC.

If a U.S. Holder makes this mark-to-market election, such U.S. Holder will be required in any year in which we are a PFIC to include as ordinary income the excess of the fair market value of such U.S. Holder’s ADSs at year-end over its basis in those ADSs. In addition, the excess, if any, of such U.S. Holder’s basis in the ADSs over the fair market value of such U.S. Holder’s ADSs at year-end is deductible as an ordinary loss in an amount equal to the lesser of (i) the amount of the excess or (ii) the amount of the net mark-to-market gains that have been included in income in prior years by such U.S. Holder. Any gain recognized by such U.S. Holder upon the sale of such U.S. Holder’s ADSs will be taxed as ordinary income in the year of sale.

A U.S. Holder’s adjusted tax basis in the ADSs will be increased by the amount of any income inclusion and decreased by the amount of any deductions under the mark-to-market rules. If a U.S. Holder makes a mark-to-market election, it will be effective for the taxable year for which the election is made and all subsequent taxable years unless the ADSs are no longer regularly traded on a qualified exchange or the IRS consents to the revocation of the election.

U.S. Holders who hold or have held our ADSs during a period when we were or are a PFIC will be subject to the foregoing rules, even if we cease to be a PFIC in subsequent years, subject to exceptions for U.S. Holders who made a timely qualified electing fund election or mark-to-market election. A U.S. Holder of PFIC stock generally must file an annual information return on IRS Form 8621. The failure to file IRS Form 8621 could result in the imposition of penalties and the extension of the statute of limitations with respect to such U.S. Holder’s U.S. federal income tax.

The U.S. federal income tax rules relating to PFICs are complex. U.S. Holders are urged to consult their tax advisors with respect to the purchase, ownership and disposition of the ADSs, the availability of the mark-to-market election and whether making the election would be advisable in their particular circumstances, and the IRS information reporting obligations with respect to the purchase, ownership and disposition of the ADSs.

Information Reporting and Backup Withholding

Distributions with respect to ADSs and proceeds from the sale, exchange or disposition of ADSs may be subject to information reporting to the IRS, and U.S. backup withholding rules. Backup withholding will not apply to a U.S. Holder who furnishes a correct taxpayer identification number and makes any other required certification or who is otherwise exempt from backup withholding. U.S. Holders who are required to establish their exempt status generally must provide such certification on U.S. IRS Form W-9. U.S. Holders are urged to consult their tax advisors regarding the application of the U.S. information reporting and backup withholding rules.

Backup withholding is not an additional tax. Amounts withheld as backup withholding may be credited against a U.S. Holder’s U.S. federal income tax liability, and a U.S. Holder may obtain a refund of

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any excess amounts withheld under the backup withholding rules by timely filing the appropriate claim for refund with the IRS and furnishing any required information.

Foreign Financial Asset Information Reporting

U.S. Holders who are either individuals or certain domestic entities may be required to submit certain information to the IRS with respect to such holder’s beneficial ownership of the ADSs, if such ADSs are not held on such holder’s behalf by a financial institution, as our ordinary shares are considered “specified foreign financial assets.” Penalties and potential other adverse tax consequences may be imposed if a U.S. Holder is required to submit such information to the IRS and fails to do so. U.S. Holders are urged to consult their tax advisors regarding the potential information reporting obligations that may be imposed with respect to the ownership and disposition of the ADSs.

The above description is not intended to constitute a complete analysis of all tax consequences relating to acquisition, ownership and disposition of the ADSs. Prospective purchasers are urged to consult their tax advisors concerning the tax consequences related to their particular circumstances.

U.K. Tax Considerations

The following is a general summary of certain limited U.K. tax considerations relating to the ownership and disposal of the ordinary shares or the ADSs and does not address all possible tax consequences relating to an investment in the ordinary shares or the ADSs. It is based on current U.K. tax law and published HM Revenue & Customs (“HMRC”) practice as of the date hereof, both of which are subject to change, possibly with retrospective effect.

Except as provided otherwise, this summary applies only to persons who are resident (and, in the case of individuals, resident for at least the last 4 complete tax years) in the United Kingdom for tax purposes and who are not resident for tax purposes in any other jurisdiction, and do not have a permanent establishment or fixed base in any other jurisdiction with which the holding of the ordinary shares or the ADSs is connected (“U.K. Holders”). Persons (a) who are not resident (or, if resident, have been resident here for less than 4 tax years) in the United Kingdom for tax purposes, including those individuals and companies who trade in the United Kingdom through a branch, agency or permanent establishment in the United Kingdom to which the ordinary shares or the ADSs are attributable, or (b) who are resident or otherwise subject to tax in a jurisdiction outside the United Kingdom, are advised to seek the advice of professional advisors in relation to their taxation obligations.

This summary is for general information only and is not intended to be, nor should it be considered to be, legal or tax advice to any particular investor. It does not address all of the tax considerations that may be relevant to specific investors in light of their particular circumstances or to investors subject to special treatment under U.K. tax law. In particular:

•

this summary only applies to the absolute beneficial owners of the ordinary shares or the ADSs and any dividends paid in respect of the ordinary shares represented by the ADSs who do not hold the ordinary shares or ADSs through an Individual Savings Account or a Self-Invested Personal Pension, and where the dividends are regarded for U.K. tax purposes as that person’s own income (and not the income of some other person); and

•

this summary: (a) only addresses the principal U.K. tax consequences for investors who hold the ordinary shares or the ADSs as capital assets/investments, (b) does not address the tax consequences that may be relevant to certain special classes of investor such as dealers, brokers or traders in shares or securities and other persons who hold the ordinary shares or the ADSs otherwise than as an investment, (c) does not address the tax consequences for holders that are financial institutions, insurance companies, collective investment schemes, pension schemes, charities or tax-exempt organizations, (d) assumes that the holder is not an officer or employee of the Company (or of any related company) and has not (and is not deemed to have) acquired the ordinary shares or the ADSs by virtue of an office or employment, and (e) assumes that the holder does not control or hold (and is not deemed to control or hold), either alone or together with one or more associated or connected persons, directly or indirectly (including through the holding of the ordinary shares), an

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interest of 10% or more in the issued share capital (or in any class thereof), voting power, rights to profits or capital of the Company, and is not otherwise connected with the Company.

This summary further assumes that a holder of ADSs is the beneficial owner of the underlying ordinary shares for U.K. tax purposes.

POTENTIAL INVESTORS IN THE ADSs SHOULD SATISFY THEMSELVES PRIOR TO INVESTING AS TO THE OVERALL TAX CONSEQUENCES, INCLUDING, SPECIFICALLY, THE CONSEQUENCES UNDER U.K. TAX LAW AND HMRC PRACTICE OF THE ACQUISITION, OWNERSHIP AND DISPOSAL OF THE ORDINARY SHARES OR ADSs IN THEIR OWN PARTICULAR CIRCUMSTANCES BY CONSULTING THEIR OWN TAX ADVISERS.

Taxation of Dividends

Withholding Tax

Dividend payments in respect of the ordinary shares represented by the ADSs may be made without withholding or deduction for or on account of U.K. tax.

Income Tax

Dividends received by individual U.K. Holders will be subject to U.K. income tax on the amount of the dividend paid.

The first £500 of dividend income received by an individual U.K. Holder for the tax year 2025/2026 will be subject to a nil rate of tax, regardless of the amount of the individual’s other taxable income.

Income within the personal allowance (charged as a nil rate band) and including the £500 allowance itself will be taken into account in determining whether income in excess of the £500 allowance falls within the basic rate, higher rate or additional rate tax bands. Dividend income in excess of the £500 allowance will not be taxed to the extent that the dividend, when treated as the top slice of the relevant U.K. Holder’s income, does not exceed the personal allowance. It will otherwise be taxed at the rate of 8.75% to the extent that the dividend, when treated as the top slice of the relevant U.K. Holder’s income, exceeds the personal allowance but does not exceed the basic rate income tax limit; at the rate of 33.75% to the extent that the dividend, when treated as the top slice of the relevant U.K. Holder’s income, exceeds the basic rate income tax limit but does not exceed the higher rate income tax limit; and at the rate of 39.35% to the extent that the dividend, when treated as the top slice of the relevant U.K. Holder’s income, exceeds the higher rate income tax limit. Additionally, a U.K. Holder’s personal allowance will be reduced by £1 for every £2 that their adjusted net income is above £100,000.

An individual holder of ordinary shares or ADSs who is not a U.K. Holder will not be chargeable to U.K. income tax on dividends paid by the company, unless such holder carries on (whether solely or in partnership) a trade, profession or vocation in the United Kingdom through a branch or agency in the United Kingdom to which the ordinary shares or the ADSs are attributable. In these circumstances, such holder may, depending on his or her individual circumstances, be chargeable to U.K. income tax on dividends received from the company.

Corporation Tax

A U.K. Holder within the charge to U.K. corporation tax may be entitled to exemption from U.K. corporation tax in respect of dividend payments. If the conditions for the exemption are not satisfied, or such U.K. Holder elects for an otherwise exempt dividend to be taxable, U.K. corporation tax will be chargeable on the gross amount of any dividends. If potential investors are in any doubt as to their position, they should consult their own professional advisers.

A corporate holder of ordinary shares or ADSs that is not a U.K. Holder will not be subject to U.K. corporation tax on dividends received from the Company, unless it carries on a trade in the United Kingdom through a permanent establishment to which the ordinary shares or the ADSs are attributable. In these circumstances, such holder may, depending on its individual circumstances and if the exemption from U.K.

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corporation tax discussed above does not apply, be chargeable to U.K. corporation tax on dividends received from the Company (the main rate of which is 25% for the 2025/2026 financial year).

Taxation of Disposals

U.K. Holders

A disposal or deemed disposal of ordinary shares or ADSs by an individual U.K. Holder may, depending on his or her individual circumstances, give rise to a chargeable gain or to an allowable loss for the purpose of U.K. capital gains tax. The capital gains tax-free allowance (called the annual exempt amount) for the tax year 2025/2026 is £3,000. If an individual U.K. Holder who is subject to U.K. income tax at either the higher or the additional rate becomes liable to U.K. capital gains tax on the disposal of ordinary shares or ADSs, the current applicable rate would be 24%. For an individual U.K. Holder who is subject to U.K. income tax at the basic rate and liable to U.K. capital gains tax on such disposal, the current applicable rate would be 18%, save to the extent that any capital gains exceed the unused basic rate tax band. In that case, the current rate applicable to the excess would be 24%.

An individual U.K. Holder who ceases to be resident in the United Kingdom (or who fails to be regarded as resident in a territory outside the United Kingdom for the purposes of double taxation relief) for a period of less than five years and who disposes of his or her ordinary shares or ADSs during that period of temporary non-residence may be liable to U.K. capital gains tax on a chargeable gain accruing on such disposal on his or her return to the United Kingdom (or upon ceasing to be regarded as resident outside the United Kingdom for the purposes of double taxation relief) (subject to available exemptions or reliefs).

A disposal (or deemed disposal) of ordinary shares or ADSs by a corporate U.K. Holder may give rise to a chargeable gain or an allowable loss for the purpose of U.K. corporation tax (the main rate of which is 25% for the 2025/2026 financial year).

Any gains or losses in respect of currency fluctuations over the period of holding the ordinary shares or ADSs would also generally be brought into account on the disposal.

Non-U.K. Holders

An individual holder who is not a U.K. Holder will not be liable to U.K. capital gains tax on capital gains realized on the disposal of his or her ordinary shares or ADSs unless such holder carries on (whether solely or in partnership) a trade, profession or vocation in the United Kingdom through a branch or agency in the United Kingdom to which the ordinary shares or ADSs are attributable. In these circumstances, such holder may, depending on his or her individual circumstances, be chargeable to U.K. capital gains tax on chargeable gains arising from a disposal of his or her ordinary shares or ADSs.

A corporate holder of ordinary shares or ADSs that is not a U.K. Holder will not be liable for U.K. corporation tax on chargeable gains realized on the disposal of its ordinary shares or ADSs unless it carries on a trade in the United Kingdom through a permanent establishment to which the ordinary shares or ADSs are attributable. In these circumstances, a disposal (or deemed disposal) of ordinary shares or ADSs by such holder may give rise to a chargeable gain or an allowable loss for the purposes of U.K. corporation tax.

Inheritance Tax

If, for the purposes of the Taxes on Estates of Deceased Persons and on Gifts Treaty 1978 between the United States and the United Kingdom, an individual holder of ordinary shares or ADSs is domiciled in the United States and is not a national of, nor deemed domiciled in (nor resident for tax purposes for at least seven of the last ten tax years in), the United Kingdom, any ordinary shares or ADSs beneficially owned by that holder will not generally be subject to U.K. inheritance tax on that holder’s death or on a gift made by that holder during his/her lifetime, provided that any applicable U.S. federal gift or estate tax liability is paid, except where (i) the ordinary shares or ADSs are part of the business property of a U.K. permanent establishment or pertain to a U.K. fixed base used for the performance of independent personal services; or (ii) the ordinary shares or ADSs are comprised in a settlement unless, at the time the settlement was made,

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the settlor was domiciled in the United States and not a national of, nor deemed domiciled in (nor resident for tax purposes for at least seven of the last ten tax years in), the United Kingdom (in which case no charge to U.K. inheritance tax should apply).

Stamp Duty and Stamp Duty Reserve Tax

Issue and Transfer of Ordinary Shares

No U.K. stamp duty is payable on the issue of the ordinary shares.

There should be no U.K. stamp duty reserve tax (“SDRT”) payable on the issue of ordinary shares to a depositary receipt system or a clearance service (for example, The Depositary Trust Company or DTC).

Transfers of ordinary shares to, or to a nominee or agent for, a person whose business is or includes issuing depositary receipts or to, or to a nominee or agent for, a person whose business is or includes the provision of clearance services, will generally be regarded by HMRC as subject to stamp duty or SDRT at 1.5% of the amount or value of the consideration or, in certain circumstances, the value of the ordinary shares transferred. In practice, this liability for stamp duty or SDRT is in general borne by such person depositing the relevant shares in the depositary receipt system or clearance service. U.K. stamp duty and SDRT will not, however, arise on a transfer of ordinary shares to a depositary receipt issuer or to a clearance service to the extent that such transfer is an “exempt capital-raising transfer” or an “exempt listing transfer”, as defined in the Finance Act 2024. Transfers of ordinary shares between depositary receipt systems and clearance services will generally be exempt from stamp duty and SDRT.

The transfer on sale of ordinary shares by a written instrument of transfer will generally be liable to U.K. stamp duty at the rate of 0.5% of the amount or value of the consideration for the transfer. The purchaser normally pays the stamp duty.

An agreement to transfer ordinary shares outside a depositary receipt system or a clearance service will generally give rise to a liability on the purchaser to SDRT at the rate of 0.5% of the amount or value of the consideration. Such SDRT is payable on the seventh day of the month following the month in which the charge arises, but where an instrument of transfer is executed and duly stamped before the expiry of a period of six years beginning with the date of that agreement, (i) any SDRT that has not been paid ceases to be payable, and (ii) any SDRT that has been paid may be recovered from HMRC, generally with interest.

We do not expect that HMRC will consider any liability to U.K. stamp duty or SDRT to have arisen in relation to the deposit with the Custodian or the depositary of the ordinary shares underlying the ADSs offered by us pursuant to this offering. However, a liability to U.K. stamp duty or SDRT may, depending on the circumstances, arise in respect of the deposit with the Custodian or the depositary of ordinary shares where ordinary shares are transferred to the Custodian or the depositary otherwise than as an integral part of an “exempt capital-raising transfer” or an “exempt listing transfer”, as defined in the Finance Act 2024.

Transfer of ADSs

Based on current HMRC published practice, no U.K. stamp duty should be payable on a written instrument transferring an ADS or on a written agreement to transfer an ADS, as an ADS is not regarded as “stock” or a “marketable security” for U.K. stamp duty purposes.

No SDRT will be payable in respect of an agreement to transfer an ADS, as an ADS is not considered to be a “chargeable security” for the purposes of SDRT.

The statements above in relation to stamp duty and SDRT apply irrespective of whether the relevant holder of ordinary shares or ADSs is resident or domiciled in the United Kingdom.

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LEGAL MATTERS

Certain legal matters of United States federal law and New York State law will be passed upon for us by Mayer Brown LLP. The validity of the ordinary shares represented by ADSs and certain other matters as to English law will be passed upon for us Mayer Brown International LLP, our English counsel. TD Securities (USA) LLC is being represented in connection with this offering by Cooley LLP, New York, New York and Cooley (UK) LLP, London, United Kingdom.

EXPERTS

The consolidated financial statements of Adaptimmune Therapeutics plc as of December 31, 2024 and 2023, and for each of the years in the three-year period ended December 31, 2024, have been incorporated by reference herein in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

SERVICE OF PROCESS AND ENFORCEMENT OF JUDGMENTS

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the U.S. Securities and Exchange Commission a registration statement (including amendments and exhibits to the registration statement) on Form S-3 under the Securities Act. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at http://www.adaptimmune.com.

Our website is not a part of this prospectus supplement and is not incorporated by reference in this prospectus supplement. We have included our website address in this prospectus solely as an inactive textual reference.

This prospectus supplement is part of a registration statement we filed with the SEC. This prospectus supplement omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information on us and our consolidated subsidiaries and the securities we are offering. Statements in this prospectus supplement concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements.

We incorporate by reference the following documents or information that we have filed with the SEC:

•

our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the SEC on March 24, 2025;

•

our Current Reports on Form 8-K filed with the SEC on March 24, 2025 and April 14, 2025; and

•

Adaptimmune Therapeutics plc
Attn: Company Secretary
60 Jubilee Avenue, Milton Park
Abingdon, Oxfordshire OX14 4RX
United Kingdom
(44) 1235 430000

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

The following is an estimate (other than the SEC registration fee) of the expenses that we may incur in connection with the securities being registered hereby. All such expenses are to be paid by the registrant.

	Amount to be paid
SEC registration fee		$	6,855.94(1)
Printing expenses			(2)
Legal fees and expenses			(2)
Accounting fees and expenses			(2)
Miscellaneous			(2)
Total		$	(2)

(1)

This amount excludes a registration fee amount of $14,699.02 associated with $355,219,192 of securities previously registered on the Registration Statement on Form S-3 (File No. 333-264208) and which remain unsold. Pursuant to Rule 415(a)(6) under the Securities Act, the amount of such registration fee associated with the offering of the unsold securities will be carried forward to be applied to the unsold securities registered under this registration statement and no additional filing fee will be due with respect to the unsold securities in connection with the filing of this registration statement.

(2)

These fees are calculated based on the number of issuances and the amount of securities offered and accordingly cannot be estimated at this time.

Item 15. Indemnification of Directors and Officers.

The registrant’s articles of association provide that, subject to the provisions of any relevant legislation, each of the registrant’s directors and other officers (excluding an auditor) are entitled to be indemnified by the registrant against all liabilities incurred by him in the execution and discharge of his duties or in relation to those duties. The Companies Act 2006 renders void an indemnity for a director against any liability attaching to him in connection with any negligence, default, breach of duty or breach of trust in relation to the company of which he is a director, subject to the following exceptions: (a) a company may purchase and maintain insurance against such liability; (b) a company may provide a “qualifying third party indemnity” (being an indemnity against certain liabilities incurred by the director to a person other than the company or an associated company as long as he is successful in defending the claim or criminal proceedings); and (c) a company may provide a “qualifying pension scheme indemnity” (being an indemnity against certain liabilities incurred in connection with the company’s activities as trustee of an occupational pension plan).

In the sales agreement, TD Cowen will agree to indemnify, under certain conditions, the registrant, members of the registrant’s board of directors, certain officers and persons who control the registrant within the meaning of the Securities Act, against certain liabilities.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers or persons controlling us pursuant to the foregoing provisions, we have been informed that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

The registrant maintains directors’ and officers’ liability insurance, subject to appreciable deductibles at the corporate level, for each wrongful act where corporate reimbursement is available to any director or officer.

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Item 16. Exhibits.

EXHIBIT INDEX

	1.1+			Form of Underwriting Agreement.
	1.2*			Sales Agreement, dated as of April 8, 2022, between Adaptimmune Therapeutics plc and TD Securities (USA) LLC (as successor to Cowen and Company, LLC) (incorporated by reference to Exhibit 1.2 to the Company’s Registration Statement on Form S-3 (file no: 333-264208)).
	1.3**			Amendment No. 1 to Sales Agreement, dated as of April 18, 2025, between Adaptimmune Therapeutics plc and TD Securities (USA) LLC.
	4.1*			Form of certificate evidencing ordinary shares (incorporated by reference to Exhibit 4.1 to the Company’s Registration Statement on Form F-1 (file no: 333-203267)).
	4.2*			Form of Deposit Agreement among Adaptimmune Therapeutics plc, Citibank, N.A., as the depositary bank and Holders and Beneficial Owners of ADSs issued thereunder (incorporated by reference to Exhibit 4.2 to the Company’s Registration Statement on Form F-1 (file no: 333-203267)).
	4.3*			Form of American Depositary Receipt (included in Exhibit 4.2) (incorporated by reference to Exhibit 4.3 to the Company’s Registration Statement on Form F-1 (file no: 333-203267)).
	4.4+			Form of Warrant Agreement (including form of warrant certificate).
	5.1**			Opinion of Mayer Brown International LLP.
	5.2**			Opinion of Mayer Brown LLP.
	23.1**			Consent of KPMG LLP.
	23.2**			Consent of Mayer Brown International LLP (included as part of Exhibit 5.1).
	23.3**			Consent of Mayer Brown LLP (included as part of Exhibit 5.2).
	24.1**			Power of Attorney (included in the signature page to this registration statement).
	107**			Filing Fee Table.

Previously filed.

Filed herewith.

To the extent applicable, to be filed as an exhibit to a Current Report on Form 8-K and incorporated by reference or by post-effective amendment.

Item 17. Undertakings.

The undersigned registrant hereby undertakes:

(1)

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

(i)

To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii)

To reflect in the prospectus any facts or events arising after the effective date of the 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 this 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 Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

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(iii)

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

provided, however, that the undertaking set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above 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 Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2)

That, for the purpose of determining any liability under the Securities Act of 1933, 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.

(3)

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.

(4)

That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(A)

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

(B)

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.

(5)

That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

The undersigned Registrant undertake 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 sellers to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i)

Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii)

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;

(iii)

The portion of any other free writing prospectus relating to the offering containing material information about the undersigned Registrant or their securities provided by or on behalf of the undersigned Registrant; and

(iv)

Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

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(6)

That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) 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 fide offering thereof.

(7)

Insofar as indemnification for liabilities arising under the Securities Act of 1933 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 Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 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, that 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 whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all 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 Oxfordshire, England, on April 18, 2025.

				ADAPTIMMUNE THERAPEUTICS PLC
				By: /s/ ADRIAN RAWCLIFFE Adrian Rawcliffe Chief Executive Officer and Director

SIGNATURES AND POWER OF ATTORNEY

In accordance with the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates stated. Each person whose signature appears below constitutes and appoints Adrian Rawcliffe and Gavin Wood and each of them severally, as his or her true and lawful attorney-in-fact and agent, each acting along 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, to sign any or all amendments (including post-effective amendments) and exhibits to the Registration Statement on Form S-3, and to any registration statement filed under SEC Rule 462, and to file the same, with all exhibits thereto, and all documents in connection therewith, with the SEC, granting unto said attorney-in-fact and agent, 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 or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

Signature	Title	Date
/s/ ADRIAN RAWCLIFFE Adrian Rawcliffe	Chief Executive Officer and Director (Principal Executive Officer)	April 18, 2025
/s/ GAVIN WOOD Gavin Wood	Chief Financial Officer (Principal Accounting and Financial Officer)	April 18, 2025
/s/ DAVID M. MOTT David M. Mott	Chairman of the Board of Directors	April 18, 2025
/s/ ANDREW ALLEN Andrew Allen, MD, PhD	Director	April 18, 2025
/s/ LAWRENCE M. ALLEVA Lawrence M. Alleva	Director	April 18, 2025
/s/ ALI BEHBAHANI Ali Behbahani, MD	Director	April 18, 2025
/s/ JOHN FUREY John Furey	Director	April 18, 2025

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	Page
ABOUT THIS PROSPECTUS		1
WHERE YOU CAN FIND MORE INFORMATION		2
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		3
THE COMPANY		4
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		5
RISK FACTORS		6
USE OF PROCEEDS		7
DESCRIPTION OF SHARE CAPITAL		8
DESCRIPTION OF AMERICAN DEPOSITARY SHARES		17
DESCRIPTION OF WARRANTS		26
DESCRIPTION OF UNITS		27
PLAN OF DISTRIBUTION		28
LEGAL MATTERS		30
EXPERTS		30

				ADAPTIMMUNE LLC
				By: /s/ ADRIAN RAWCLIFFE Name: Adrian Rawcliffe Title: Chief Executive Officer and Director