NOTICE OF 2022 ANNUAL GENERAL MEETING NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 NOTICE OF 2022 ANNUAL GENERAL MEETING NOTICE is hereby given that the 2022 annual general meeting o

NOTICE OF 2022 ANNUAL GENERAL MEETING

77-78 Cannon Street, London, England, EC4N 6AF

Company number: 03308778

NOTICE OF 2022 ANNUAL

NOTICE is hereby given that the 2022 annual general meeting of NuCana plc (the Company ) will be held on

23 June 2022 at 11.00am at Lochside House, 3 Lochside Way, Edinburgh EH12 9DT, UK for transaction of the following business:

Ordinary Resolutions

To consider and, if thought fit, pass the following resolutions (1 to 8 inclusive), which will be proposed as ordinary resolutions:

To consider and, if thought fit, pass the following resolutions 9 and 10, which will be proposed as special resolutions:

NOTICE OF 2022 ANNUAL GENERAL MEETING

The directors of the Company consider that all the proposals to be considered at the AGM are in the best interests of the Company and its shareholders as a

whole and are most likely to promote the success of the Company. The directors unanimously recommend that you vote in favour of all the proposed resolutions as they intend to do in respect of their own beneficial holdings.

YOUR VOTE IS IMPORTANT. At the time of

print, it s our intention that members will be able to attend the AGM in person however you are strongly encouraged to vote on all resolutions in advance of the AGM by appointing the Chair of the meeting as your proxy. Further details on how

shareholders can appoint the Chair of the meeting as their proxy are set out in this document. For our members and colleagues safety, we ll be following the latest government guidance on Covid-19 at the

time of the event. We ask any members attending the AGM to arrive and depart promptly.

NOTICE OF 2022 ANNUAL GENERAL MEETING

The following notes explain your general rights as a member and your right to attend and vote at the annual general meeting or to appoint someone else to vote

The Company may treat as invalid a CREST proxy instruction in the circumstances set out in Regulation 35(5)(a)

of the Uncertificated Securities Regulations 2001.

NOTICE OF 2022 ANNUAL GENERAL MEETING

audit of the Company s accounts (including the auditor s report and the conduct of the audit) that are to be laid before the annual general meeting; or (b) any circumstance

connected with an auditor of the Company ceasing to hold office since the previous meeting at which annual accounts and reports were laid in accordance with Section 437 of the Act. The Company may not require the members requesting any such

website publication to pay its expenses in complying with Sections 527 or 528 of the Act. Where the Company is required to place a statement on a website under Section 527 of the Act, it must forward the statement to the Company s auditors

not later than the time when it makes the statement available on the website. The business which may be dealt with at the annual general meeting includes any statement that the Company has been required, under Section 527 of the Act, to publish

NOTICE OF 2022 ANNUAL GENERAL MEETING

EXPLANATORY NOTES TO THE RESOLUTIONS PROPOSED AT THE ANNUAL GENERAL MEETING

The resolutions to be proposed at the AGM of the Company to be held on 23 June 2022 at 11.00am are set out in this Notice of AGM. The following notes

provide an explanation to the resolutions being put to shareholders.

Ordinary Resolutions

Resolutions 1 to 8 are proposed as ordinary resolutions. Assuming that a quorum is present, 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 and entitled to vote. On a poll, 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.

Resolution 1- 2 Re-election and Election of a director

Articles of Association there are three classes of board members (Class I, Class II and Class III) with each class having a specified term of office. The Company s Articles of Association require the Class II directors to retire

from office this year and for any directors who were appointed by the directors since the 2021 AGM to stand for election. Dr. Cyrille Leperlier currently serves as a Class II director. Dr. Cyrille Leperlier is retiring and (being

eligible) is standing for re-election as a Class II director at the AGM. Dr. Elliott Levy currently serves as a Class II director, and (being eligible) is standing for election as a

Class II director at the annual general meeting. Biographical information for each director standing for re-election and election is included on page 10 of this Notice.

THE BOARD RECOMMENDS A VOTE FOR THE RE-ELECTION OF DR. CYRILLE LEPERLIER TO THE BOARD OF DIRECTORS AND

FOR THE ELECTION OF DR. ELLIOTT LEVY TO THE BOARD OF DIRECTORS.

Resolution 3 Re-appointment of

The Act requires that auditors be appointed at each general meeting, at which accounts are laid, to hold office until the next AGM. The

appointment of Ernst & Young LLP as auditors of the Company terminates at the conclusion of the AGM. They have indicated their willingness to stand for reappointment as auditors of the Company until the conclusion of the AGM in 2023.

The Audit Committee has assessed the effectiveness, independence and objectivity of the auditors, Ernst & Young LLP, and concluded that the

auditors were in all respects effective.

THE BOARD RECOMMENDS A VOTE FOR THE RE-APPOINTMENT OF

ERNST & YOUNG LLP AS AUDITORS.

Resolution 4 Authorising and fixing the remuneration of the auditors

This resolution gives authority to the directors to determine the auditors remuneration.

It is normal practice for shareholders to resolve at the AGM that the directors shall decide on the level of remuneration of the auditors for the audit work

to be carried out by them in the next financial year. The amount of the remuneration paid to the auditors for the next financial year will be disclosed in the next audited accounts of the Company.

THE BOARD RECOMMENDS A VOTE FOR THE AUTHORISATION OF THE DIRECTORS TO DETERMINE THE AUDITORS

Resolution 5 Laying of accounts

The directors are required to present to shareholders at the AGM, the annual accounts of the Company for the year ended 31 December 2021,

the Strategic Report, the Directors Report and the Auditors Report on the accounts.

THE BOARD RECOMMENDS A VOTE FOR THE RESOLUTION TO

RECEIVE THE ANNUAL ACCOUNTS OF THE COMPANY FOR THE YEAR ENDED 31 DECEMBER 2021, THE STRATEGIC REPORT, THE DIRECTORS REPORT AND THE AUDITORS REPORT ON THE ACCOUNTS.

Resolution 6 Directors Remuneration Report

Shareholders are invited to cast their vote on the Directors Remuneration Report, in accordance with Section 439 of the Act. The Directors

Remuneration Report is set out on pages 17 to 26 of the Company s annual accounts and reports for the year ended 31 December 2021. The vote is advisory in nature and therefore no entitlement to remuneration is conditional on the

passing of this resolution.

THE BOARD RECOMMENDS A VOTE FOR THE RESOLUTION TO RECEIVE AND APPROVE THE DIRECTORS REMUNERATION

REPORT FOR THE FINANCIAL YEAR ENDED 31 DECEMBER 2021.

Background to Resolution 7 and Special Resolution 9

matter of U.K. company law, directors of a company incorporated in England must have authority from shareholders to allot or grant rights to subscribe for, or to convert any security into, the company s shares. In addition, when an allotment of

shares is for cash, the company must first offer those shares on the same terms to existing shareholders of the company on a pro-rata basis (commonly referred to as statutory

pre-emption rights) unless these statutory pre-emption rights are dis-applied, by approval of the shareholders.

Resolutions 7 and 9, which we refer to as our Share Issuance Proposals, ask our shareholders for authority for the directors to allot shares or

grant rights over shares up to an aggregate nominal amount of 1,200,000 and the power for the directors to allot shares or grant rights over shares for cash up to an aggregate nominal amount of 1,200,000 on a non-preemptive basis. This authority and power would expire on the conclusion of our AGM to be held in 2023.

NOTICE OF 2022 ANNUAL GENERAL MEETING

Many of our peer companies are listed and incorporated in the United States, and are not subject to similar

share issuance restrictions. We are asking you to approve our Share Issuance Proposals to allow us to continue to execute on our business and growth strategy in a timely and competitive manner.

We have no immediate plans, arrangements or understandings with respect to any share issuances pursuant to our Share Issuance Proposals.

Should our shareholders not approve resolutions 7 and 9, whilst we appreciate that we would still have the ability to seek shareholder approval in connection

with a specific issuance of shares on a case by case basis by convening general meetings from time to time, we do not believe that such an approach is a workable alternative to obtaining approval of resolutions 7 and 9 at the AGM as we propose. The

uncertainty as to whether we could obtain shareholder approval for a specific issuance, as well as the delays we would experience in seeking and obtaining such approval, could be harmful to the terms of such a share issuance. In addition, the case-by-case approval approach ignores market windows and other deal timing and competitive realities.

Specifically, the requirement to first offer shares that we propose to issue for cash to all of our existing shareholders in time-consuming pro-rata rights offerings would considerably reduce the speed at which we could complete capital-raising activities undertaken in furtherance of our growth strategy, would increase our costs, might otherwise make it

difficult or impossible for us to complete such transactions, and could put us at a distinct competitive disadvantage to our peer companies.

capital and the ability to raise equity capital at short notice have been important factors that have contributed to our ability to execute our long-term growth strategy. In practice, offering shares to existing shareholders in accordance with U.K.

statutory pre-emption rights can be time-consuming, so U.K. market practice for listed companies is to annually seek a shareholder resolution waiving or dis-applying

pre-emption rights over new share issuances for cash, up to an agreed limit. We fully appreciate that our proposals are in excess of the investment advisory guidance in this regard and for this reason, our

proposals may attract a negative voting recommendation from certain proxy advisory firms. However, we have established a track record since our IPO in October 2017 of having secured shareholder support for an annual resolution dis-applying pre-emption rights over amounts of share capital in excess of the investment advisory guidance.

We believe the request for authorisation and disapplication of pre-emption rights sought will provide us with the

flexibility to raise equity capital that we believe we may require at this stage of development of the Company. This recognises the fact that as a development-stage business, we have needed access to equity capital to ensure that we can maintain the

business appropriately capitalised to enable us to pursue our research and development strategy. We have publicly stated that we believe our existing cash resources will be sufficient to fund the Company into 2025. As such, we have no intent to

raise additional capital, but we believe it is in the interests of all shareholders to ensure that we retain the ability to raise equity capital on reasonably short notice if the need to do so should arise. We propose to seek an authority (to expire

at the 2023 AGM) to allot shares or grant rights over shares and under this authority to seek the power to allot shares or grant rights over shares for cash on a non-preemptive basis over the equivalent of 57%

of our current issued share capital.

The Share Issuance Proposals are consistent with U.S. capital markets practice and U.S. governance standards, and,

if approved, will keep us on an equal footing with our peer companies which are incorporated and listed in the United States. We believe that the Share Issuance Proposals are appropriate to the needs of the Company and in the interests of

shareholders. We are therefore asking you to approve the Share Issuance Proposals to allow us to continue to execute on our business and growth strategy in a timely and competitive manner.

The Share Issuance Proposals, if approved, will

allow our Board of Directors continued flexibility to issue shares subject to other requirements of Nasdaq Stock Market and the Securities and Exchange Commission. The Share Issuance Proposals, as proposed:

Resolution 7 - Authority to allot shares

may only allot shares or grant rights over shares if authorised to do so by shareholders.

Under this resolution the Board is seeking the authority to

allot shares in the Company or grant rights to subscribe for or to convert any security into shares in the Company up to an aggregate nominal amount of 1,200,000 such authority, unless previously revoked or varied by the Company, to expire at

the conclusion of the AGM of the Company to be held in 2023.

THE BOARD RECOMMENDS YOU VOTE FOR THE RESOLUTION SO AUTHORISING THE DIRECTORS.