NCNA / NuCana plc - Depositary Receipt (Common Stock) - Arquivamentos da SEC, Relatório Anual, Declaração de Procuração

NuCana Appoints Ian Webster as Chief Financial Officer

EX-99.1 Exhibit 99.1 NuCana Appoints Ian Webster as Chief Financial Officer Edinburgh, United Kingdom, June 1, 2026 (GLOBE NEWSWIRE)—NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”), a clinical-stage biopharmaceutical company focused on significantly improving treatment outcomes for patients with cancer, announced the appointment of Ian Webster as Chief Financial Officer, effective today. Ian

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 (Commission File No. 001-38215) NUCA

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 (Commission File No. 001-38215) NUCANA PLC (T

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2026 2025 (in thousands, except per share data) £ £ Research and development expenses (3,213 ) (1,725 ) Administrative expenses (1,568 ) (

EX-99.1 Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2026 2025 (in thousands, except per share data) £ £ Research and development expenses (3,213 ) (1,725 ) Administrative expenses (1,568 ) (1,067 ) Net foreign exchange gains (losses) 363 (59 ) Operating loss (4,418 ) (2,851 ) Finance income 143 25 Loss before tax (4,2

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NuCana Reports First Quarter 2026 Financial Results and Provides Business Update Final Data from Phase 2 Expansion Study of NUC-7738 Expected in 2026 NUC-7738 Receives FDA IND Clearance: Planned Initial Studies to Focus on Melanoma Advancing Addition

EX-99.3 Exhibit 99.3 NuCana Reports First Quarter 2026 Financial Results and Provides Business Update Final Data from Phase 2 Expansion Study of NUC-7738 Expected in 2026 NUC-7738 Receives FDA IND Clearance: Planned Initial Studies to Focus on Melanoma Advancing Additional Indications and Combination Strategies Cash Runway Expected to Extend into 2029 Edinburgh, United Kingdom, May 14, 2026 (GLOBE

NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778

EX-99.1 Exhibit 99.1 A New Era in Oncology Notice of 2026 Annual General Meeting Monday, 8th June 2026 at 11.00am Venue: Lochside House 3 Lochside Way Edinburgh EH12 9DT U.K. NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 2 NOTICE OF 2026 ANNUAL GENERAL MEETING NOTICE OF 2026 ANNUAL GENERAL MEETING NOTICE is hereby given that the 2026 annual general meeting of N

Nucana A New Era in Oncology For the year ended 31 December 2025 ANNUAL REPORT

EX-99.2 Exhibit 99.2 Nucana A New Era in Oncology For the year ended 31 December 2025 ANNUAL REPORT Nucana A New Era in OncologyDirectorsRegistered OfficeHugh Griffith77-78 Cannon StreetAndrew KayLondonMartin MellishEC4N 6AFCyrille LeperlierU.K.Elliott LevyAdam George (retired 21 March 2025)Global HeadquartersBali Muralidhar (retired 21 October 2025)Lochside House3 Lochside WaySecretaryEdinburghMa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 (Commission File No. 001-38215) NUCAN

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executiv

Consent of Independent Registered Public Accounting Firm

Exhibit 15.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3/A No. 333-281576) of NuCana plc and in the related Prospectus, (2) Registration Statement (Form S-8 No. 333-223476) pertaining to both NuCana BioMed Limited Option Share Schemes (Including Management Enterp

EX-4.5

Exhibit 4.5 NuCana plc Company Number 03308778 2020 LONG-TERM INCENTIVE PLAN Approved by shareholders on 25 June 2020 Adopted by the board of directors on 25 June 2020 and altered by the board of directors on 9 January 2026 CONTENTS Rule Page 1. INTRODUCTION 2 2. DEFINITIONS AND INTERPRETATION 2 3. PROVISIONS RELATING TO A GRANT OF AN AWARD 5 4. GRANT OF AWARDS 6 5. ISO LIMITS 8 6. VESTING OF AWAR

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.2 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Ian Webster, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fa

Table 1: Newly Registered Securities

Calculation of Filing Fee Tables S-8 NuCana plc Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Ordinary Shares, nominal value 0.

I. The Need for an Insider Trading Policy II. What is Material Non-Public Information? III. The Consequences of Insider Trading IV. Our Policy V. Individual Responsibility VI. Additional Prohibited Transactions VII. Summary of Insider Dealing provisi

Exhibit 19.1 NUCANA PLC INSIDER TRADING POLICY TABLE OF CONTENTS Page I. The Need for an Insider Trading Policy 2 II. What is Material Non-Public Information? 2 III. The Consequences of Insider Trading 4 IV. Our Policy 5 General Prohibition on Trading 5 Transactions by Family Members, Others in Your Household and Entities You Control 5 Other Companies’ Non-public Information 5 Personal or Independ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 (Commission File No. 001-38215) NUC

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal execut

1. INTERPRETATION 2. PROVISIONS RELATING TO THE GRANT OF OPTIONS 3. LIMITS AND OTHER RESTRICTIONS OF THE SCHEME RULES 4. NON-ASSIGNABILITY OF OPTIONS 5. EXERCISE CONDITIONS 6. EXERCISE OF OPTION 7. CESSATION OF EMPLOYMENT 8. CHANGE OF CONTROL AND SAL

Exhibit 4.4 RULES OF THE NuCana BioMed Limited 2016 SHARE OPTION SCHEME (INCLUDING ENTERPRISE MANAGEMENT INCENTIVES & INCENTIVE STOCK OPTIONS) Approved and Adopted by the Board of NuCana BioMed Ltd on 14 January 2016, as amended on 14 September 2017 and on 2 October 2017 CONTENTS 1. INTERPRETATION 1 2. PROVISIONS RELATING TO THE GRANT OF OPTIONS 7 3. LIMITS AND OTHER RESTRICTIONS OF THE SCHEME RUL

ARTICLE I DEFINITIONS ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT ARTICLE III AMENDMENTS TO THE FORM OF ADR, AND ISSUED AND OUTSTANDING ADRs ARTICLE IV REPRESENTATIONS AND WARRANTIES ARTICLE V MISCELLANEOUS

Exhibit 2.2 AMENDMENT NO. 1 TO AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of August 11, 2025 15815758v.2 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions 1 Section 1.2 Effective Date 1 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Hugh S. Griffith, Chief Executive Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company

NuCana Reports Fourth Quarter and Year-End 2025 Financial Results and Provides Business Update NUC-7738 Demonstrates Clinical Activity and Favorable Safety in Patients with PD-1 Inhibitor-Resistant Melanoma Final Data from Phase 2 Expansion Study of

EX-99.1 Exhibit 99.1 NuCana Reports Fourth Quarter and Year-End 2025 Financial Results and Provides Business Update NUC-7738 Demonstrates Clinical Activity and Favorable Safety in Patients with PD-1 Inhibitor-Resistant Melanoma Final Data from Phase 2 Expansion Study of NUC-7738 Expected in 2026 Advancing Additional Indications and Combination Strategies Cash Runway Expected to Extend into 2029 Ed

PART 2

Exhibit 4.17 MINUTE OF VARIATION between CUSTODIAN PROPERTY INCOME REIT PLC and NUCANA PLC Property: 2nd Floor East Suite, Lochside House, 3 Lochside Way, Edinburgh, EH12 9DT Brodies LLP Capital Square 58 Morrison Street Edinburgh EH3 8BP T: 0131 228 3777 F: 0131 228 3878 DX.ED10 Ref: RWW/GRMI/MDO/CUS0011.00093 FAS 0468/1468 2025 TABLE OF CONTENTS 1 Definitions and interpretation 3 2 Variation of

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.1 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Hugh S. Griffith, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a materi

As filed with the Securities and Exchange Commission on March 19, 2026

S-8 As filed with the Securities and Exchange Commission on March 19, 2026 Registration No.

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.2 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Ian Webster, Interim Chief Financial Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Compa

As filed with the Securities and Exchange Commission on March 19, 2026 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F

As filed with the Securities and Exchange Commission on March 19, 2026 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 (Commission File No. 001-38215) N

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exec

NuCana Appoints Theresa Bruce as Chief Operating Officer

EX-99.1 Exhibit 99.1 NuCana Appoints Theresa Bruce as Chief Operating Officer Edinburgh, United Kingdom, January 6, 2026 (GLOBE NEWSWIRE) -NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”), a clinical-stage biopharmaceutical company focused on improving treatment outcomes for patients with cancer, announced the appointment of Theresa Bruce as Chief Operating Officer, effective January 1, 2026.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 (Commission File No. 001-38215) NUCANA P

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

NuCana Presents Latest Data Demonstrating Clinical Activity and Favorable Safety for NUC-7738 in Patients with PD-1-Resistant Melanoma Data Presented at ESMO IO 2025 include Partial Responses, Durable Disease Control, and No New Safety Signals, Reinf

EX-99.1 Exhibit 99.1 NuCana Presents Latest Data Demonstrating Clinical Activity and Favorable Safety for NUC-7738 in Patients with PD-1-Resistant Melanoma Data Presented at ESMO IO 2025 include Partial Responses, Durable Disease Control, and No New Safety Signals, Reinforcing Earlier Findings EDINBURGH, United Kingdom, December 10, 2025 (GLOBE NEWSWIRE) - NuCana plc (NASDAQ: NCNA) (“NuCana” or th

NuCana Reports Third Quarter 2025 Financial Results and Provides Business Announced Encouraging Data on both NUC-7738 and NUC-3373 Initial Data from the Expansion Study of NUC-7738 Expected in Q4 2025 with Final Data Expected in 2026 Compliant with A

EX-99.3 Exhibit 99.3 NuCana Reports Third Quarter 2025 Financial Results and Provides Business Update Announced Encouraging Data on both NUC-7738 and NUC-3373 Initial Data from the Expansion Study of NUC-7738 Expected in Q4 2025 with Final Data Expected in 2026 Compliant with All Nasdaq Continued Listing Criteria Well Capitalized with Anticipated Cash Runway into 2029 Edinburgh, United Kingdom, No

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2025 2024 2025 2024 (in thousands, except per share data) £ £ £ £ Research and development exp

EX-99.1 Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2025 2024 2025 2024 (in thousands, except per share data) £ £ £ £ Research and development expenses (2,172 ) (3,736 ) (11,001 ) (17,288 ) Administrative expenses (1,399 ) (1,358 ) (6,989 ) (4,448 ) Other income 3 2,692 —  2

NuCana Announces Grant of Composition-of-Matter Patent for NUC-7738 in China

EX-99.1 Exhibit 99.1 NuCana Announces Grant of Composition-of-Matter Patent for NUC-7738 in China Edinburgh, United Kingdom, November 5, 2025 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”) announced that the China National Intellectual Property Administration (“CNIPA”) has granted an important patent covering the composition of matter for NUC-7738. This patent (ZL 2020107

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 (Commission File No. 001-38215) N

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exec

NuCana Presents Encouraging Data on NUC-7738 in Combination with PD-1 Inhibitors using Primary Patient-Derived Organoids and Autologous Tumor- Infiltrating Lymphocytes at the ESMO Congress 2025 NUC-7738 Synergizes with PD-1 Inhibitors to Promote Canc

EX-99.1 Exhibit 99.1 NuCana Presents Encouraging Data on NUC-7738 in Combination with PD-1 Inhibitors using Primary Patient-Derived Organoids and Autologous Tumor- Infiltrating Lymphocytes at the ESMO Congress 2025 NUC-7738 Synergizes with PD-1 Inhibitors to Promote Cancer Cell Death Data Reinforces Mechanism of Action along with Efficacy and Safety Profile of NUC-7738 BERLIN, October 18, 2025 (GL

NuCana Announces Encouraging Data for NUC-3373 in Combination with Anti-PD-1 Therapy NUC-3373 Plus Pembrolizumab Continues to Show Favorable Efficacy and Safety Profile in Heavily Pre-treated Patients Latest Data Cut-Off Shows Patient with Melanoma R

EX-99.1 Exhibit 99.1 NuCana Announces Encouraging Data for NUC-3373 in Combination with Anti-PD-1 Therapy NUC-3373 Plus Pembrolizumab Continues to Show Favorable Efficacy and Safety Profile in Heavily Pre-treated Patients Latest Data Cut-Off Shows Patient with Melanoma Remains Progression-Free at 23 Months with a Durable Partial Response Preclinical Data Corroborate Immunogenic Effects of NUC-3373

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 (Commission File No. 001-38215) N

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exec

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal ex

NuCana Compliant with All Nasdaq Continued Listing Criteria Anticipated Cash Runway into 2029

EX-99.1 Exhibit 99.1 NuCana Compliant with All Nasdaq Continued Listing Criteria Anticipated Cash Runway into 2029 EDINBURGH, United Kingdom, September 5, 2025 (GLOBE NEWSWIRE) - NuCana plc (Nasdaq: NCNA) (“NuCana” or the “Company”) announced that it has received formal notification from The Nasdaq Stock Market on September 4, 2025 confirming that the Company is in compliance with all applicable N

NuCana to Present Data on NUC-7738’s Synergy with PD-1 Inhibitors at the ESMO Congress 2025

EX-99.1 Exhibit 99.1 NuCana to Present Data on NUC-7738’s Synergy with PD-1 Inhibitors at the ESMO Congress 2025 EDINBURGH, United Kingdom, September 3, 2025 (GLOBE NEWSWIRE) - NuCana plc (Nasdaq: NCNA) (“NuCana” or the “Company”) announced a presentation at the upcoming annual European Society for Medical Oncology (“ESMO”) congress being held October 17-21, 2025 in Berlin, Germany (the “ESMO Cong

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 (Commission File No. 001-38215) NU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NuCana Reports Second Quarter 2025 Financial Results and Provides Business Update First Patients Dosed on Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma Initial Data from the Expansio

EX-99.3 Exhibit 99.3 NuCana Reports Second Quarter 2025 Financial Results and Provides Business Update First Patients Dosed on Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma Initial Data from the Expansion Study of NUC-7738 Expected in Q4 2025 with Final Data in 2026 Additional Data from the Ongoing Phase 1b/2 Study of NUC-3373 in

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended June 30, For the Six Months Ended June 30, Notes 2025 2024 2025 2024 (in thousands, except per share data) £ £ £ £ Research and development expenses (7,104 ) (6,769 ) (8,829 ) (13,552 ) Administrative expenses (4,523 ) (1,509 ) (5,590 ) (3,090 ) Net foreign exchange (losses) gains (202 ) (7

NuCana Announces ADS Ratio Change

EX-99.1 Exhibit 99.1 NuCana Announces ADS Ratio Change Edinburgh, United Kingdom, August 1, 2025 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”) announces that it will implement the Company’s previously disclosed plans to change the ratio of its American Depository Shares (“ADSs”) to its ordinary shares from one (1) ADS, representing twenty-five (25) ordinary shares, to on

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 (Commission File No. 001-38215) NUCANA PLC

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive off

NuCana Cancels All Outstanding Series A Warrants Following Strategic ATM Execution

EX-99.1 Exhibit 99.1 NuCana Cancels All Outstanding Series A Warrants Following Strategic ATM Execution Edinburgh, United Kingdom, July 21, 2025 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”) announces it has successfully canceled all remaining Series A Warrants, issued in the registered direct offering on May 7, 2025, pursuant to its letter agreements with the holders of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office) I

AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of May 7, 2025 TABLE OF CONTENTS

Exhibit (a)(ii) AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC and CITIBANK, N.

AMENDMENT NO. 1 TO AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [l], 2025 Table of Contents

Exhibit (a)(i) AMENDMENT NO. 1 TO AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [l], 2025 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions 1 Section 1.2 Effective Date 1 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2 Section 2.1 De

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 POST-EFFECTIVE AMENDMENT NO. 1 TO FORM F-6 REGISTRATION STATEMENT THE SECURITIES ACT OF 1933 FOR AMERICAN DEPOSITARY SHARES EVIDENCED BY AMERICAN DEPOSITARY RECEIPTS NUCANA PLC (Exact name of

As filed with the Securities and Exchange Commission on July 16, 2025 Registration No.

NuCana Announces Plan to Implement ADS Ratio Change

Exhibit 99.1 NuCana Announces Plan to Implement ADS Ratio Change Edinburgh, United Kingdom, July 11, 2025 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”) announced plans to change the ratio of its American Depository Shares (“ADSs”) to its ordinary shares from one (1) ADS, representing twenty-five (25) ordinary shares, to one (1) ADS representing five thousand (5,000) ordi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

NUCANA PLC AMERICAN DEPOSITARY SHARES SALES AGREEMENT

Exhibit 1.1 NUCANA PLC AMERICAN DEPOSITARY SHARES SALES AGREEMENT June 27, 2025 A.G.P./Alliance Global Partners 590 Madison Avenue New York, NY 10022 Laidlaw & Company (UK) Ltd. 521 Fifth Avenue New York, NY 10175 Ladies and Gentlemen: NuCana plc, a public limited company organized under the laws of England and Wales (the “Company”), confirms its agreement (this “Agreement”) with A.G.P./Alliance G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

[Signature Pages Follow]

EX-10.1 Exhibit 10.1 June 17, 2025 NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Attention: Hugh S. Griffith Re: Letter Agreement Ladies and Gentlemen: Reference is made to (i) that certain Securities Purchase Agreement, dated as of May 5, 2025 (the “Purchase Agreement”), by and between NuCana plc (the “Company”) and the undersigned (each, an “Investor” and collectively, the “Invest

NuCana plc American Depositary Shares representing Ordinary Shares

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-281576 PROSPECTUS SUPPLEMENT (To prospectus dated June 24, 2025) NuCana plc $100,000,000 American Depositary Shares representing Ordinary Shares We have entered into a sales agreement, or the Sales Agreement, with A.G.P./Alliance Global Partners, or A.G.P., and Laidlaw & Company (UK) Ltd., or Laidlaw, relating to the sal

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCA

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executi

NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom

CORRESP NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom June 20, 2025 VIA EDGAR U.

AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of May 7, 2025

Exhibit 4.2 AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC and CITIBANK, N.A., as Depositary, and ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of May 7, 2025 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 1 Section 1.1 “ADS Record Date” 1 Section 1.2 “Affiliate” 1 Section 1.3 “American Depositary Receipt(s)”, “ADR(s)” and “Receipt(s)” 2 Se

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (

Form 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

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

F-3/A Table of Contents As filed with the Securities and Exchange Commission on June 18, 2025 Registration No.

Calculation of Filing Fee Tables Form F-3 NuCana plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation  or Carry Forward Rule Amount Regist

Exhibit 107 Calculation of Filing Fee Tables Form F-3 NuCana plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation  or Carry Forward Rule Amount Registered  Proposed Maximum  Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration  Fee Carry Forward  Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Equity Ordinary shares, nominal value £0.

LETTER

June 13, 2025 CERTIFIED MAIL RETURN RECEIPT REQUESTED Hugh S. Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Re: NuCana plc Registration Statement on Form F-3 Filed August 15, 2024 File No. 333-281576 Dear Hugh S. Griffith: It has been more than nine months since you filed this registration statement and it is now out of date. Within 30 days from the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCA

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executi

NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778

Exhibit 99.1 Notice of 2025 Annual General Meeting Friday, 27th June 2025 at 11.00am Venue: Lochside House 3 Lochside Way Edinburgh EH12 9DT U.K. NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 2 NOTICE OF 2025 ANNUAL GENERAL MEETING NOTICE OF 2025 ANNUAL GENERAL MEETING NOTICE is hereby given that the 2025 annual general meeting of NuCana plc (the “Company”) wil

Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George (retired 21 March 2025) Cyrille Leperlier Global Headquarters Elliott Levy Lochside House 3 Lochside Way Secretar

Exhibit 99.2 Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George (retired 21 March 2025) Cyrille Leperlier Global Headquarters Elliott Levy Lochside House 3 Lochside Way Secretary Edinburgh Martin Quinn EH12 9DT U.K. Auditors E: [email protected] Ernst & Young LLP www.nucana.com 144 Morrison Street Edinburgh EH3 8EX

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2025 2024 (in thousands, except per share data) £ £ Research and development expenses (1,725 ) (6,783 ) Administrative expenses (1,067 ) (

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2025 2024 (in thousands, except per share data) £ £ Research and development expenses (1,725 ) (6,783 ) Administrative expenses (1,067 ) (1,581 ) Net foreign exchange (losses) gains (59 ) 95 Operating loss (2,851 ) (8,269 ) Finance income 25 126 Loss before tax (2,826 ) (8,1

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securities and

NuCana Reports First Quarter 2025 Financial Results and Provides Business Update Initiation of Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma Initial Data from the Expansion Study of

Exhibit 99.4 NuCana Reports First Quarter 2025 Financial Results and Provides Business Update Initiation of Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma Initial Data from the Expansion Study of NUC-7738 Expected in Q4 2025 with Final Data in 2026 Additional Data from the Ongoing Phase 1b/2 Study of NUC-3373 in Combination with Pe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

SUPPLEMENTAL RISK FACTORS

Exhibit 99.3 SUPPLEMENTAL RISK FACTORS Investing in our securities involves a high degree of risk. You should carefully consider the risks described under “Risk Factors” in our Annual Report on Form 20-F for the fiscal year ended December 31, 2024, as filed with the U.S. Securities and Exchange Commission (“SEC”), and all other information contained in, or incorporated by reference in, our filings

NuCana plc 2,452,935 American Depositary Shares Representing 61,323,375 Ordinary Shares Series A Warrants to Purchase up to 10,845,985 American Depositary Shares Representing up to 271,149,625 Ordinary Shares Series B Warrants to Purchase up to 10,84

424B4 Table of Contents Filed Pursuant to Rule 424(b)(4) Registration Number 333-286716 PROSPECTUS NuCana plc 2,452,935 American Depositary Shares Representing 61,323,375 Ordinary Shares Series A Warrants to Purchase up to 10,845,985 American Depositary Shares Representing up to 271,149,625 Ordinary Shares Series B Warrants to Purchase up to 10,845,985 American Depositary Shares Representing up to

[Signature Page to Follow]

CORRESP May 5, 2025 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: NuCana plc Registration Statement on Form F-1, as amended File No. 333-286737 Request for Acceleration of Effective Date Ladies and Gentlemen: Pursuant to Rule 461 of the General Rules and Regulations under the Securities Act of 1933, as amended (the “

NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom

CORRESP NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom May 5, 2025 VIA EDGAR U.

SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

Exhibit 4.7 SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES A ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “Initial

PLACEMENT AGENCY AGREEMENT

EX-1.1 Exhibit 1.1 PLACEMENT AGENCY AGREEMENT April [•], 2025 Hugh Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Dear Mr. Griffith: This letter agreement (the “Agreement”) constitutes the agreement between Laidlaw & Company (UK) Ltd. (“Laidlaw”), as placement agent (the “Placement Agent”) and NuCana plc, a company incorporated under the laws of Engla

SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

Exhibit 4.8 SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES B ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “Initial

SERIES B WARRANT LOCK-UP AGREEMENT

Exhibit 10.17 SERIES B WARRANT LOCK-UP AGREEMENT This Series B Warrant Lock-Up Agreement (this “Agreement”) is dated as of April [ ], 2025, between NuCana plc, a public limited company organized under the laws of the England and Wales (the “Company”), and you, as the purchaser identified on the signature page hereto (including its successors and assigns, a “Holder”. Capitalized terms used and not

SECURITIES PURCHASE AGREEMENT

Exhibit 10.16 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of April [•], 2025, between NuCana plc, a public limited company organized under the laws of the England and Wales (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHE

As filed with the Securities and Exchange Commission on May 1, 2025.

Table of Contents As filed with the Securities and Exchange Commission on May 1, 2025.

NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom

CORRESP NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom May 1, 2025 VIA EDGAR U.

[Signature Page to Follow]

CORRESP May 1, 2025 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: NuCana plc Registration Statement on Form F-1, as amended File No. 333-286737 Withdrawal of Request for Acceleration of Effective Date Ladies and Gentlemen: Reference is made to our letter, filed as correspondence via EDGAR on April 29, 2025, in which

PLACEMENT AGENCY AGREEMENT

Exhibit 1.1 PLACEMENT AGENCY AGREEMENT April [•], 2025 Hugh Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Dear Mr. Griffith: This letter agreement (the “Agreement”) constitutes the agreement between Laidlaw & Company (UK) Ltd. (“Laidlaw”), as placement agent (the “Placement Agent”) and NuCana plc, a company incorporated under the laws of England and

SERIES B WARRANT LEAK-OUT AGREEMENT

Exhibit 10.17 SERIES B WARRANT LEAK-OUT AGREEMENT This Series B Warrant Leak-Out Agreement (this “Agreement”) is dated as of April [ ], 2025, between NuCana plc, a public limited company organized under the laws of the England and Wales (the “Company”), and you, as the purchaser identified on the signature page hereto (including its successors and assigns, a “Holder”. Capitalized terms used and no

SECURITIES PURCHASE AGREEMENT

Exhibit 10.16 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of April [•], 2025, between NuCana plc, a public limited company organized under the laws of the England and Wales (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHE

PRE-FUNDED ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Initial Exercise Date: April [•], 2025

Exhibit 4.6 PRE-FUNDED ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Initial Exercise Date: April [•], 2025 THIS PRE-FUNDED ADS PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “Initial

[Signature Page to Follow]

CORRESP April 29, 2025 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: NuCana plc Registration Statement on Form F-1, as amended File No. 333-286737 Request for Acceleration of Effective Date Ladies and Gentlemen: Pursuant to Rule 461 of the General Rules and Regulations under the Securities Act of 1933, as amended (th

SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

Exhibit 4.7 SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES A ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “Initial

NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom

CORRESP NUCANA PLC 3 Lochside Way Edinburgh, EH12 9DT United Kingdom April 29, 2025 VIA EDGAR U.

SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

Exhibit 4.8 SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES B ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “Initial

BOSTON LOS ANGELES MIAMI NEW YORK SAN DIEGO SAN FRANCISCO TORONTO WASHINGTON MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C.

CORRESP1           One Financial Center Boston, MA 02111 617 542 6000 mintz.com April 29, 2025 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, N.E. Washington, D.C. 20549 Attention: Joshua Gorsky and Tim Buchmiller Re:   NuCana plc Registration Statement on Form F-1 Filed on April 24, 2025 CIK No. 0001709626 Ladies and Gentlemen: W

As filed with the Securities and Exchange Commission on April 29, 2025.

Table of Contents As filed with the Securities and Exchange Commission on April 29, 2025.

ARTICLES OF ASSOCIATION NUCANA PLC adopted by special resolution passed on 23 April 2025

EX-3.1 Exhibit 3.1 ARTICLES OF ASSOCIATION OF NUCANA PLC adopted by special resolution passed on 23 April 2025 CONTENTS Articles Page 1. EXCLUSION OF OTHER REGULATIONS 1 2. DEFINITIONS AND INTERPRETATION 1 3. LIABILITY OF MEMBERS 4 4. SHARE CAPITAL 4 5. VARIATION OF RIGHTS 6 6. ALTERATION OF CAPITAL 6 7. SHARE CERTIFICATES 7 8. CALLS ON SHARES 8 9. LIEN ON SHARES 9 10. FORFEITURE AND SURRENDER OF

SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

EX-4.7 Exhibit 4.7 SERIES A ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES A ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “

PLACEMENT AGENCY AGREEMENT

EX-1.1 Exhibit 1.1 PLACEMENT AGENCY AGREEMENT April [•], 2025 Hugh Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Dear Mr. Griffith: This letter agreement (the “Agreement”) constitutes the agreement between Laidlaw & Company (UK) Ltd. (“Laidlaw”), as placement agent (the “Placement Agent”) and NuCana plc, a company incorporated under the laws of Engla

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-6 REGISTRATION STATEMENT THE SECURITIES ACT OF 1933 FOR AMERICAN DEPOSITARY SHARES EVIDENCED BY AMERICAN DEPOSITARY RECEIPTS NUCANA PLC (Exact name of issuer of deposited securities as

As filed with the Securities and Exchange Commission on April 24, 2025 Registration No.

As filed with the Securities and Exchange Commission on April 23, 2025.

F-1 Table of Contents As filed with the Securities and Exchange Commission on April 23, 2025.

LETTER

April 24, 2025 Hugh S. Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Re: NuCana plc Registration Statement on Form F-1 Filed April 24, 2025 File No. 333-286716 Dear Hugh S. Griffith: We have reviewed your amended registration statement and have the following comments. Please respond to this letter by amending your registration statement and providing

Calculation of Filing Fee Tables FORM F-1 (Form Type) NUCANA PLC (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities  Security  Type Security Class Title Fee  Calculation  Rule Amount  Registered  Proposed  Max

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables FORM F-1 (Form Type) NUCANA PLC (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities  Security  Type Security Class Title Fee  Calculation  Rule Amount  Registered  Proposed  Maximum  Offering Price Per Share Maximum Aggregate Offering  Price (1)(2)  Fee Rate Amount of  Registration  Fee Fees to Be Paid Equity Ordinary Shares, nominal value £0.

AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [•], 2025

Exhibit 4.4 AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC and CITIBANK, N.A., as Depositary, and ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [•], 2025 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 1 Section 1.1 “ADS Record Date” 1 Section 1.2 “Affiliate” 1 Section 1.3 “American Depositary Receipt(s)”, “ADR(s)” and “Receipt(s)” 2 Sect

AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024 Table of Contents

Exhibit (a)(ii) AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions. 1 Section 1.2 Effective Date. 1 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2 Section 2.1 Deposit Agreeme

SECURITIES PURCHASE AGREEMENT

Exhibit 10.16 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of April [•], 2025, between NuCana plc, a public limited company organized under the laws of the England and Wales (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”). WHE

BOSTON LOS ANGELES MIAMI NEW YORK SAN DIEGO SAN FRANCISCO TORONTO WASHINGTON MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C.

DRSLTR           One Financial Center Boston, MA 02111 617 542 6000 mintz.com April 23, 2025 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, N.E. Washington, D.C. 20549 Attention: Joshua Gorsky and Tim Buchmiller Re:    NuCana plc Draft Registration Statement on Form F-1 Submitted on April 4, 2025 CIK No. 0001709626 Ladies and Gent

AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024

EX-4.3 Exhibit 4.3 AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions 1 Section 1.2 Effective Date 1 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2 Section 2.1 Deposit Agreem

SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025

EX-4.8 Exhibit 4.8 SERIES B ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Issuance Date: April [•], 2025 THIS SERIES B ADS PURCHASE WARRANT (“Warrant”) certifies that, for value received, [•] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the Issuance Date (such date, the “

AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [●], 2025 TABLE OF CONTENTS

Exhibit (a)(i) AMENDED AND RESTATED DEPOSIT AGREEMENT by and among NUCANA PLC and CITIBANK, N.

Exhibit (d)

Exhibit (d) April 24, 2025 Citibank, N.A. – ADR Department 388 Greenwich Street New York, New York 10013 Ladies and Gentlemen: We refer to the Registration Statement on Form F-6 (the “Registration Statement”) to be filed with the Securities and Exchange Commission (the “SEC”) by the legal entity created by the Deposit Agreement, dated as of October 2, 2017, by and among Citibank, N.A., as Deposita

PRE-FUNDED ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Initial Exercise Date: April [•], 2025

EX-4.6 Exhibit 4.6 PRE-FUNDED ADS PURCHASE WARRANT NUCANA PLC Warrant Shares: [•] Initial Exercise Date: April [•], 2025 THIS PRE-FUNDED ADS PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 (Commission File No. 001-38215) NUCANA PLC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office)

LETTER

April 17, 2025 Hugh S. Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Re: NuCana plc Draft Registration Statement on Form F-1 Submitted April 4, 2025 CIK No. 0001709626 Dear Hugh S. Griffith: We have conducted a limited review of your draft registration statement and have the following comments. Please respond to this letter by providing any requested

Confidential Treatment Requested by Nucana plc Pursuant to 17 C.F.R. Section 200.83 As confidentially submitted to the U.S. Securities and Exchange Commission on April 4, 2025. This draft registration statement has not been publicly filed with the U.

Table of Contents Confidential Treatment Requested by Nucana plc Pursuant to 17 C.

NUCANA PLC CLAWBACK POLICY

Exhibit 97.1 NUCANA PLC CLAWBACK POLICY I. Introduction The Board of Directors (the “Board”) of NuCana plc (the “Company”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company’s pay-for-performance compensation philosophy. The Board has therefore adopted this polic

Consent of Independent Registered Public Accounting Firm

Exhibit 15.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-281576) of NuCana plc and in the related Prospectus, (2) Registration Statement (Form S-8 No. 333-223476) pertaining to both NuCana BioMed Limited Option Share Schemes (Including Management Enterpri

Registers of Scotland

Exhibit 4.16 22/39203 Books of Council and Session Extract Registered 28 Oct 2022 MINUTE OF VARIATION CUSTODIAN REIT PLC NUCANA PLC BRODIES LLP DX ED 10 EDINBURGH Registers of Scotland 22/39203 AT EDINBURGH the Twenty Eighth day of October Two thousand and twenty two the Deed hereinafter reproduced was presented for registration in the Books of the Lords of Council and Session for preservation and

NuCana Reports Fourth Quarter and Year-End 2024 Financial Results and Provides Business Update Remains on Track to Initiate an Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma in 2025 D

EX-99.1 Exhibit 99.1 NuCana Reports Fourth Quarter and Year-End 2024 Financial Results and Provides Business Update Remains on Track to Initiate an Expansion Study of NUC-7738 in Combination with Pembrolizumab for Patients with PD-1 Inhibitor-Resistant Melanoma in 2025 Data from the Expansion Study to Support Interaction with FDA and Define Regulatory Strategy for NUC-7738 Data from the Ongoing Ph

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.1 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Hugh S. Griffith, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a materi

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.2 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Ian Webster, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 (Commission File No. 001-38215) NUC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Hugh S. Griffith, Chief Executive Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company

NUCANA PLC INSIDER TRADING POLICY TABLE OF CONTENTS

Exhibit 19.1 NUCANA PLC INSIDER TRADING POLICY TABLE OF CONTENTS Page I. The Need for an Insider Trading Policy 2 II. What is Material Non-Public Information? 2 III. The Consequences of Insider Trading 4 IV. Our Policy 5 General Prohibition on Trading 5 Transactions by Family Members, Others in Your Household and Entities You Control 5 Other Companies’ Non-public Information 5 Personal or Independ

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.2 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Ian Webster, Director of Finance of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company for the p

As filed with the Securities and Exchange Commission on March 20, 2025 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F

As filed with the Securities and Exchange Commission on March 20, 2025 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 (Commission File No. 001-38215) NUC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778

Exhibit 99.1 Notice of General Meeting Monday, 7th April 2025 at 11.00am Venue: Lochside House 3 Lochside Way Edinburgh EH12 9DT U.K NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 1 NOTICE OF GENERAL MEETING NOTICE is hereby given that a general meeting of NuCana plc (the “Company”) will be held on 7 April 2025 at 11.00am at Lochside House, 3 Lochside Way, Edinb

Joint Filing Agreement

EX-99.1 2 tm256670d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 Joint Filing Agreement In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the common shares of NuCana plc and further agree that this agreement be included as a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2025 (Commission File No. 001-38215)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2025 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 (Commission File No. 001-38215)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executi

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2024 2023 2024 2023 (in thousands, except per share data) £ £ £ £ Research and development exp

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2024 2023 2024 2023 (in thousands, except per share data) £ £ £ £ Research and development expenses (3,736 ) (7,439 ) (17,288 ) (18,203 ) Administrative expenses (1,358 ) (1,375 ) (4,448 ) (4,777 ) Net foreign exchange (losses) gai

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securities and

NuCana Reports Third Quarter 2024 Financial Results and Provides Business Update Presented Encouraging Phase 2 Data on NUC-7738 in Combination with Pembrolizumab at the European Society for Medical Oncology (ESMO) Congress 2024 Announced Promising Ph

Exhibit 99.3 NuCana Reports Third Quarter 2024 Financial Results and Provides Business Update Presented Encouraging Phase 2 Data on NUC-7738 in Combination with Pembrolizumab at the European Society for Medical Oncology (ESMO) Congress 2024 Announced Promising Phase 1b/2 Data on NUC-3373 in Combination with Pembrolizumab or Docetaxel Anticipated Cash Runway into Q2 2025 Edinburgh, United Kingdom,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

NuCana Announces Encouraging Initial Data from Phase 1b/2 Modular Study of NUC-3373 in Combination with Pembrolizumab or Docetaxel Patients with Advanced Solid Tumors who had Exhausted All Other Treatment Options and were PD-(L)1 Experienced Achieved

Exhibit 99.1 NuCana Announces Encouraging Initial Data from Phase 1b/2 Modular Study of NUC-3373 in Combination with Pembrolizumab or Docetaxel Patients with Advanced Solid Tumors who had Exhausted All Other Treatment Options and were PD-(L)1 Experienced Achieved Significant Tumor Volume Reductions and Prolonged Progression Free Survival Following Treatment with NUC-3373 plus Pembrolizumab One Pat

NCNA / NuCana plc - Depositary Receipt (Common Stock) / BAILLIE GIFFORD & CO Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 NUCANA PLC (Amendment No.4) - (Name of Issuer) Ordinary Shares - (Title of Class of Securities) 67022C205 - (CUSIP Number) 30 September 2024 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal ex

NuCana plc Up to $5,407,000 American Depositary Shares representing Ordinary Shares

424B5 Filed Pursuant to Rule 424(b)(5) Registration No. 333-258941 AMENDMENT NO. 2 DATED SEPTEMBER 30, 2024 to Prospectus Supplement dated August 27, 2021, as amended on March 27, 2024 (To Prospectus dated August 27, 2021) NuCana plc Up to $5,407,000 American Depositary Shares representing Ordinary Shares This Amendment No. 2 to Prospectus Supplement (this “Amendment”) amends our prospectus supple

NuCana Announces Grant of Composition-of-Matter Patent for NUC-7738 in the United States

Exhibit 99.1 NuCana Announces Grant of Composition-of-Matter Patent for NUC-7738 in the United States Edinburgh, United Kingdom, September 25, 2024 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced the issuance of a new patent by the United States Patent and Trademark Office (USPTO) covering NUC-7738’s composition of matter. This patent (US12,054,510) is expected to serve as a key component o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal ex

NuCana Presents Encouraging Data on NUC-7738 in Combination with Pembrolizumab in PD-1 Inhibitor Refractory and Resistant Melanoma Patients at the ESMO Congress 2024 Combination of NUC-7738 plus Pembrolizumab Resulted in Prolonged Progression Free Su

EX-99.1 Exhibit 99.1 NuCana Presents Encouraging Data on NUC-7738 in Combination with Pembrolizumab in PD-1 Inhibitor Refractory and Resistant Melanoma Patients at the ESMO Congress 2024 Combination of NUC-7738 plus Pembrolizumab Resulted in Prolonged Progression Free Survival, a Compelling Disease Control Rate including Partial Responses, and a Favorable Safety Profile Barcelona, Spain, September

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal ex

NuCana Announces Update for Phase 2 Randomized Colorectal Cancer Study NuTide:323 Study to be Discontinued Following Pre-Planned Initial Analysis and Recommendation from the Steering Committee NuTide:701 and NuTide:303 Studies Continue Unchanged with

Exhibit 99.1 NuCana Announces Update for Phase 2 Randomized Colorectal Cancer Study NuTide:323 Study to be Discontinued Following Pre-Planned Initial Analysis and Recommendation from the Steering Committee NuTide:701 and NuTide:303 Studies Continue Unchanged with Encouraging Data on NUC-7738 plus Pembrolizumab to be Presented at the ESMO Annual Conference in September Edinburgh, United Kingdom, Au

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 (Commission File No. 001-38215) NU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

LETTER

August 16, 2024 Hugh S. Griffith Chief Executive Officer NuCana plc 3 Lochside Way Edinburgh, EH12 9DT United Kingdom Re: NuCana plc Registration Statement on Form F-3 Filed August 15, 2024 File No. 333-281576 Dear Hugh S. Griffith: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 (Commission File No. 001-38215) NU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

Calculation of Filing Fee Tables Form F-3 NuCana plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registe

Exhibit 107 Calculation of Filing Fee Tables Form F-3 NuCana plc (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Equity Ordinary shares, nominal value £0.

As filed with the Securities and Exchange Commission on August 15, 2024

Table of Contents As filed with the Securities and Exchange Commission on August 15, 2024 Registration No.

NUCANA PLC [ ] Trustee Dated as of [  ] Subordinated Debt Securities

Exhibit 4.8 NUCANA PLC Issuer AND [ ] Trustee INDENTURE Dated as of [  ] Subordinated Debt Securities CROSS-REFERENCE TABLE (1) Section of Trust Indenture Act of 1939, as Amended Section of Indenture 310(a). 7.09 310(b). 7.08 7.10 310(c). Inapplicable 311(a). 7.13(a) 311(b). 7.13(b) 311(c). Inapplicable 312(a). 5.02(a) 312(b). 5.02(b) 312(c). 5.02(c) 313(a). 5.04(a) 313(b). 5.04(a) 313(c). 5.04(a)

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended June 30, For the Six Months Ended June 30, Notes 2024 2023 2024 2023 (in thousands, except per share data) £ £ £ £ Research and development expenses (6,769 ) (3,959 ) (13,552 ) (10,764 ) Administrative expenses (1,509 ) (1,754 ) (3,090 ) (3,402 ) Net foreign exchange (losses) gains (74 ) (5

AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024

Exhibit 4.3 AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of April 16, 2024 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions 1 Section 1.2 Effective Date 2 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2    Section 2.1 Deposit Agreement

NUCANA PLC Dated as of [ ] Senior Debt Securities

Exhibit 4.7 NUCANA PLC Issuer AND [ ] Trustee INDENTURE Dated as of [ ] Senior Debt Securities CROSS-REFERENCE TABLE (1) Section of Trust Indenture Act of 1939, as Amended Section of Indenture 310(a). 7.09 310(b). 7.08 7.10 310(c). Inapplicable 311(a). 7.13(a) 311(b). 7.13(b) 311(c). Inapplicable 312(a) 5.02(a) 312(b). 5.02(b) 312(c). 5.02(c) 313(a). 5.04(a) 313(b). 5.04(a) 313(c). 5.04(a) 5.04(b)

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NuCana Reports Second Quarter 2024 Financial Results and Provides Business Update Key Data Readouts on Track for All Programs in 2024 Anticipated Cash Runway into Q1 2025

Exhibit 99.3 NuCana Reports Second Quarter 2024 Financial Results and Provides Business Update Key Data Readouts on Track for All Programs in 2024 Anticipated Cash Runway into Q1 2025 Edinburgh, United Kingdom, August 15, 2024 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced financial results for the second quarter ended June 30, 2024 and provided an update on its broad clinical development

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2024 (Commission File No. 001-38215) NUCANA PLC (

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office) I

NuCana Reports First Quarter 2024 Financial Results and Provides Business Update Key Data Readouts on Track for All Programs in 2024 Randomized Phase 2 Study of 182 Second-Line Colorectal Cancer Patients Fully Enrolled NUC-7738 plus Pembrolizumab Dem

Exhibit 99.3 NuCana Reports First Quarter 2024 Financial Results and Provides Business Update Key Data Readouts on Track for All Programs in 2024 Randomized Phase 2 Study of 182 Second-Line Colorectal Cancer Patients Fully Enrolled NUC-7738 plus Pembrolizumab Demonstrated Encouraging Anti-Cancer Activity in Several Patients who were Resistant to PD-1 Inhibitors Anticipated Cash Runway into Q1 2025

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securities and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCANA PLC (T

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office) In

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2024 2023 (in thousands, except per share data) £ £ Research and development expenses (6,783 ) (6,805 ) Administrative expenses (1,581 ) (

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2024 2023 (in thousands, except per share data) £ £ Research and development expenses (6,783 ) (6,805 ) Administrative expenses (1,581 ) (1,648 ) Net foreign exchange gains (losses) 95 (695 ) Operating loss (8,269 ) (9,148 ) Finance income 126 287 Loss before tax (8,143 ) (8

Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George Cyrille Leperlier Global Headquarters Elliott Levy Lochside House 3 Lochside Way Secretary Edinburgh Martin Quinn

Exhibit 99.2 Annual Report 2023 for the year ended 31 December 2023 Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George Cyrille Leperlier Global Headquarters Elliott Levy Lochside House 3 Lochside Way Secretary Edinburgh Martin Quinn EH12 9DT U.K. Auditors E: [email protected] Ernst & Young LLP www.nucana.com 144 Mo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCAN

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executiv

NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778

EX-99.1 Exhibit 99.1 Notice f 2024 Annual General Meeting Tuesday, 18th June 2024 at 11.00am Venue: Lochside House 3 Lochside Way Edinburgh EH12 9DT U.K. NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 NOTICE OF 2024 ANNUAL GENERAL MEETING NOTICE OF 2024 ANNUAL GENERAL MEETING NOTICE is hereby given that the 2024 annual general meeting of NuCana plc (the “Company

NuCana Regains Compliance with Nasdaq Minimum Bid Price Requirement

Exhibit 99.1 NuCana Regains Compliance with Nasdaq Minimum Bid Price Requirement Edinburgh, United Kingdom, May 1, 2024 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA), (“NuCana” or the “Company”), announced that it has received a written notification (the “Notification Letter”) from the Listing Qualifications Department of the Nasdaq Stock Market, LLC (“Nasdaq”) informing the Company that it has reg

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCAN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive of

NuCana Announces Completion of ADS Ratio Change

Exhibit 99.1 NuCana Announces Completion of ADS Ratio Change Edinburgh, United Kingdom, April 16, 2024 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced that the Company’s previously disclosed plans to change the ratio of its American Depositary Shares (“ADSs”) to its ordinary shares from one (1) ADS, representing one (1) ordinary share, to one (1) ADS representing twenty-five (25) ordinary s

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 (Commission File No. 001-38215) NUCANA PLC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 (Commission File No. 001-38215) NUC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

NuCana Presents Data at the AACR 2024 Annual Meeting Highlighting the Ability of NUC-7738 to Profoundly Alter Tumor Biology in a Paired Biopsy Clinical Study NUC-7738 Reprograms Cancer Cell Lipid Metabolism to Make Tumors Less Aggressive and Promote

Exhibit 99.1 NuCana Presents Data at the AACR 2024 Annual Meeting Highlighting the Ability of NUC-7738 to Profoundly Alter Tumor Biology in a Paired Biopsy Clinical Study NUC-7738 Reprograms Cancer Cell Lipid Metabolism to Make Tumors Less Aggressive and Promote Cancer Cell Death NUC-7738 Alters Ribosome Biogenesis and the Regulation of Genes Critical for Cancer Growth and Survival San Diego, Cali

NuCana Announces Plan to Implement ADS Ratio Change

Exhibit 99.1 NuCana Announces Plan to Implement ADS Ratio Change Edinburgh, United Kingdom, March 27, 2024 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced plans to change the ratio of its American Depository Shares (“ADSs”) to its ordinary shares from one (1) ADS, representing one (1) ordinary share, to one (1) ADS representing twenty-five (25) ordinary shares (the “ADS Ratio”). The change

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2024 (Commission File No. 001-38215) NUCANA PLC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office)

AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [l], 2024 Table of Contents

Exhibit (a)(i) AMENDMENT NO. 1 TO DEPOSIT AGREEMENT by and among NUCANA PLC AND CITIBANK, N.A., as Depositary, AND ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of [l], 2024 Table of Contents Page ARTICLE I DEFINITIONS 1 Section 1.1 Definitions. 1 Section 1.2 Effective Date. 1 ARTICLE II AMENDMENTS TO DEPOSIT AGREEMENT 2 Section 2.1 Deposit Agreement Ame

NUCANA PLC

Exhibit (b)(i) NUCANA PLC April 6, 2020 Citibank, N.A. – ADR Department 388 Greenwich Street New York, NY 10013 Attn: Ryan Everett Program ADSs (CUSIP No.: 67022C106) Ladies and Gentlemen: Reference is made to the Deposit Agreement, dated as of October 2, 2017, as amended and supplemented from time to time (the “Deposit Agreement”), by and among NuCana plc, a public limited company incorporated un

DEPOSIT AGREEMENT by and among NuCana PLC CITIBANK, N.A., as Depositary, ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of October 2, 2017 TABLE OF CONTENTS

Exhibit (a)(ii) DEPOSIT AGREEMENT by and among NuCana PLC and CITIBANK, N.A., as Depositary, and ALL HOLDERS AND BENEFICIAL OWNERS OF AMERICAN DEPOSITARY SHARES ISSUED HEREUNDER Dated as of October 2, 2017 TABLE OF CONTENTS ARTICLE I DEFINITIONS 1 Section 1.1 “ADS Record Date” 1 Section 1.2 “Affiliate” 1 Section 1.3 “American Depositary Receipt(s)”, “ADR(s)” and “Receipt(s)” 1 Section 1.4 “America

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 POST-EFFECTIVE AMENDMENT NO. 1 TO FORM F-6 REGISTRATION STATEMENT THE SECURITIES ACT OF 1933 FOR AMERICAN DEPOSITARY SHARES EVIDENCED BY AMERICAN DEPOSITARY RECEIPTS NUCANA plc (Exact name of

As filed with the Securities and Exchange Commission on March 27, 2024 Registration No.

NuCana plc Up to $7,250,000 American Depositary Shares representing Ordinary Shares

Filed Pursuant to Rule 424(b)(5) Registration No. 333-258941 AMENDMENT NO. 1 DATED MARCH 27, 2024 to Prospectus Supplement dated August 27, 2021 (To Prospectus dated August 27, 2021) NuCana plc Up to $7,250,000 American Depositary Shares representing Ordinary Shares This Amendment No. 1 to Prospectus Supplement (this “Amendment”) amends our prospectus supplement dated August 27, 2021 (the “Prospec

NuCana plc

Exhibit (b)(ii) NuCana plc As of July 31, 2018 Citibank, N.A. - ADR Department 388 Greenwich Street New York, New York 10013 Restricted ADSs /Affiliate (CUSIP No.: 67022C999) Ladies and Gentlemen: Reference is made to the Deposit Agreement, dated as of October 2, 2017, as amended and supplemented from time to time (the “Deposit Agreement”), by and among NuCana plc, a public limited company incorpo

Consent of Independent Registered Public Accounting Firm

Exhibit 15.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-258941) of NuCana plc and in the related Prospectus, (2) Registration Statement (Form S-8 No. 333-223476) pertaining to both NuCana BioMed Limited Option Share Schemes (Including Management Enterpri

NuCana Reports Fourth Quarter and Year-End 2023 Financial Results and Provides Business Update Announced Encouraging Updates from NUC-3373 and NUC-7738 Demonstrating Promising Efficacy and Safety Pipeline Continues to Advance with Key Data Readouts E

Exhibit 99.1 NuCana Reports Fourth Quarter and Year-End 2023 Financial Results and Provides Business Update Announced Encouraging Updates from NUC-3373 and NUC-7738 Demonstrating Promising Efficacy and Safety Pipeline Continues to Advance with Key Data Readouts Expected for All Programs in 2024 Randomized Phase 2 Study of 171 Second-Line Colorectal Cancer Patients Fully Recruited Anticipated Cash

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.2 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Donald Munoz, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material f

NUCANA PLC CLAWBACK POLICY

Exhibit 97.1 NUCANA PLC CLAWBACK POLICY I. Introduction The Board of Directors (the “Board”) of NuCana plc (the “Company”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company’s pay-for-performance compensation philosophy. The Board has therefore adopted this polic

Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.1 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Hugh S. Griffith, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a materi

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.2 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Donald Munoz, Chief Financial Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company for

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 13.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Hugh S. Griffith, Chief Executive Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company

Registers of Scotland

Exhibit 4.16 22/39203 Books of Council and Session Extract Registered 28 Oct 2022 MINUTE OF VARIATION CUSTODIAN REIT PLC NUCANA PLC BRODIES LLP DX ED 10 EDINBURGH Registers of Scotland 22/39203 AT EDINBURGH the Twenty Eighth day of October Two thousand and twenty two the Deed hereinafter reproduced was presented for registration in the Books of the Lords of Council and Session for preservation and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2024 (Commission File No. 001-38215) NUCANA PLC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2024 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office)

As filed with the Securities and Exchange Commission on March 20, 2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F

As filed with the Securities and Exchange Commission on March 20, 2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

NCNA / NuCana plc - Depositary Receipt (Common Stock) / Sofinnova Venture Partners VIII, L.P. - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13D (RULE 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a) (Amendment No. 3)* NuCana plc (Name of Issuer) American Depositary Shares representing Ordinary Shares, nominal value £0.04 per share (Title of Class of Securities) 67022C106 (CUSIP Numb

NCNA / NuCana plc - Depositary Receipt (Common Stock) / Griffith Hugh - SC 13G/A Passive Investment

SC 13G/A 1 d778712dsc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 6)* NUCANA PLC (Name of Issuer) Ordinary Shares (Title of Class of Securities) 67022C106 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

NCNA / NuCana plc - Depositary Receipt (Common Stock) / BAILLIE GIFFORD & CO Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 NUCANA PLC (Amendment No.3) - (Name of Issuer) Ordinary Shares - (Title of Class of Securities) 67022C106 - (CUSIP Number) 29 December 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Supplemental Risk Factors

Exhibit 99.3 Supplemental Risk Factors Our business has significant risks. You should carefully consider the following risk factors and all other information contained in our Annual Report on Form 20-F for the year ended December 31, 2022 (our “Annual Report”) and in subsequent reports filed on Form 6-K, including our consolidated financial statements and the related notes. The risks and uncertain

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2023 (Commission File No. 001-38215)

Form 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principa

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2023 2022 2023 2022 (in thousands, except per share data) £ £ £ £ Research and development exp

EX-99.1 Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2023 2022 2023 2022 (in thousands, except per share data) £ £ £ £ Research and development expenses (7,439 ) (7,386 ) (18,203 ) (23,238 ) Administrative expenses (1,375 ) (1,715 ) (4,777 ) (5,756 ) Net foreign exchange gain

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NuCana Reports Third Quarter 2023 Financial Results and Provides Business Update Announced Encouraging Updates from NUC-3373 and NUC-7738 Demonstrating Promising Efficacy and Safety Data Pipeline Continues to Advance with Data Updates Expected for al

EX-99.4 Exhibit 99.4 NuCana Reports Third Quarter 2023 Financial Results and Provides Business Update Announced Encouraging Updates from NUC-3373 and NUC-7738 Demonstrating Promising Efficacy and Safety Data Pipeline Continues to Advance with Data Updates Expected for all Programs in 2024 Well Capitalized with Anticipated Cash Runway into 2025 Edinburgh, United Kingdom, November 16, 2023 (GLOBE NE

NuCana Announces Listing Transfer to Nasdaq Capital Market

Exhibit 99.1 NuCana Announces Listing Transfer to Nasdaq Capital Market Edinburgh, United Kingdom, November 10, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) (“NuCana” or the “Company”) announced today that it has received approval from Listing Qualifications Department of the Nasdaq Stock Market (“Nasdaq”) to transfer the listing of its American Depositary Shares (“ADSs”) from the Nasdaq Glob

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2023 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2023 (Commission File No. 001-38215) N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executiv

NuCana Presents Promising Data on NUC-7738 at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 Data from the NuTide:701 Study Indicate NUC-7738 May Potentiate the Activity of Anti-PD-1 Agents in Patients w

Exhibit 99.1 NuCana Presents Promising Data on NUC-7738 at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 Data from the NuTide:701 Study Indicate NUC-7738 May Potentiate the Activity of Anti-PD-1 Agents in Patients who were Refractory to or Progressed on Prior Immunotherapy, including Anti-PD-1 Therapy Several Patients Achieved Reductions in Tumor Vol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2023 (Commission File No. 001-38215) N

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exec

NuCana Presents Encouraging Data on NUC-3373 in Colorectal Cancer at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 NUC-3373 Demonstrates Promising Anti-Tumor Activity and a Favorable Safety Profile as p

EX-99.1 Exhibit 99.1 NuCana Presents Encouraging Data on NUC-3373 in Colorectal Cancer at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 NUC-3373 Demonstrates Promising Anti-Tumor Activity and a Favorable Safety Profile as part of NUFIRI-bevacizumab and NUFOX-bevacizumab in Second-line Colorectal Cancer Patients Several Second-line Colorectal Cancer P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2023 (Commission File No. 001-38215)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal execut

NuCana Announces Presentations at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023

Exhibit 99.1 NuCana Announces Presentations at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 Edinburgh, United Kingdom, September 18, 2023 (GLOBE NEWSWIRE)—NuCana plc (NASDAQ: NCNA) announced four presentations at the upcoming AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics 2023 being held October 11-15, 2023 in B

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securities and

NuCana Reports Second Quarter 2023 Financial Results and Provides Business Update On Track to Present Data Updates from All Ongoing Clinical Studies in the Second Half of 2023 Well Capitalized with Anticipated Cash Runway into 2025

EX-99.3 Exhibit 99.3 NuCana Reports Second Quarter 2023 Financial Results and Provides Business Update On Track to Present Data Updates from All Ongoing Clinical Studies in the Second Half of 2023 Well Capitalized with Anticipated Cash Runway into 2025 Edinburgh, United Kingdom, August 16, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced financial results for the second quarter ended Ju

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended June 30, For the Six Months Ended June 30, Notes 2023 2022 2023 2022 (in thousands, except per share data) £ £ £ £ Research and development expenses (3,959 ) (6,406 ) (10,764 ) (15,852 ) Administrative expenses (1,754 ) (1,889 ) (3,402 ) (4,040 ) Net foreign exchange (losses) gains (564 ) 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2023 (Commission File No. 001-38215) NU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2023 (Commission File No. 001-38215) NUCANA PLC (

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offic

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2023 2022 (in thousands, except per share data) £ £ Research and development expenses (6,805 ) (9,446 ) Administrative expenses (1,648 ) (

Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended March 31, Notes 2023 2022 (in thousands, except per share data) £ £ Research and development expenses (6,805 ) (9,446 ) Administrative expenses (1,648 ) (2,152 ) Net foreign exchange (losses) gains (695 ) 1,131 Operating loss (9,148 ) (10,467 ) Finance income 287 31 Loss before tax (8,861 )

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

NuCana Reports First Quarter 2023 Financial Results and Provides Business Update Multiple Important Data Readouts Remain on Track for 2023 Well Capitalized with Anticipated Cash Runway into 2025

Exhibit 99.3 NuCana Reports First Quarter 2023 Financial Results and Provides Business Update Multiple Important Data Readouts Remain on Track for 2023 Well Capitalized with Anticipated Cash Runway into 2025 Edinburgh, United Kingdom, May 17, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced financial results for the first quarter ended March 31, 2023 and provided an update on its broad

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCANA PLC (T

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive office

Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George Cyrille Leperlier Global Headquarters Elliott Levy Lochside House James Healy (retired 27 April 2022) 3 Lochside

EX-99.2 Exhibit 99.2 Directors Registered Office Hugh Griffith 77-78 Cannon Street Andrew Kay London Bali Muralidhar EC4N 6AF Martin Mellish U.K. Adam George Cyrille Leperlier Global Headquarters Elliott Levy Lochside House James Healy (retired 27 April 2022) 3 Lochside Way Edinburgh Secretary EH12 9DT Martin Quinn U.K. E: [email protected] Auditors www.nucana.com Ernst & Young LLP 144 Morrison Stre

NOTICE OF 2023 ANNUAL GENERAL MEETING

EX-99.1 Exhibit 99.1 NOTICE OF 2023 ANNUAL GENERAL MEETING NuCana plc 77-78 Cannon Street, London, England, EC4N 6AF Company number: 03308778 NOTICE OF 2023 ANNUAL GENERAL MEETING NOTICE is hereby given that the 2023 annual general meeting of NuCana plc (the “Company”) will be held on 15 June 2023 at 11.00am at Lochside House, 3 Lochside Way, Edinburgh EH12 9DT, U.K. for transaction of the followi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCAN

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executiv

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCAN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive of

NuCana Announces Receipt of Nasdaq Notice

EX-99.1 Exhibit 99.1 NuCana Announces Receipt of Nasdaq Notice Edinburgh, United Kingdom, May 12, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced that it received written notification (the “Notification Letter”) from The Nasdaq Stock Market LLC (“Nasdaq”) dated May 9, 2023, indicating that, based upon a closing bid price of less than $1.00 per share for the Company’s American Depositar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2023 (Commission File No. 001-38215) NUC

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal execut

NuCana Presents Data at the AACR 2023 Annual Meeting Highlighting Novel NUC-7738 Mechanisms of Action NUC-7738 Reduces Secreted Forms of PD-L1 Indicating Potential Synergy with Checkpoint Inhibitors NUC-7738 Decreases Glutaminase in vitro and in Canc

EX-99.1 Exhibit 99.1 NuCana Presents Data at the AACR 2023 Annual Meeting Highlighting Novel NUC-7738 Mechanisms of Action NUC-7738 Reduces Secreted Forms of PD-L1 Indicating Potential Synergy with Checkpoint Inhibitors NUC-7738 Decreases Glutaminase in vitro and in Cancer Tissue Demonstrating Potential for Anti-Cancer Activity in Highly Metabolic Tumors Orlando, Florida April 14, 2023 (GLOBE NEWS

Minute of Variation between the registrant and Custodian REIT PLC, dated October 27, 2022

Exhibit 14.6 22/39203 Books of Council and Session Extract Registered 28 Oct 2022 MINUTE OF VARIATION CUSTODIAN REIT PLC NUCANA PLC BRODIES LLP DX ED 10 EDINBURGH Registers of Scotland 22/39203 AT EDINBURGH the Twenty Eighth day of October Two thousand and twenty two the Deed hereinafter reproduced was presented for registration in the Books of the Lords of Council and Session for preservation and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2023 (Commission File No. 001-38215) NUCANA PLC

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offi

Rule 13a-14(a)/15d-14(a) Certification of Chief Financial Officer, as adopted pursuant to §302 of the Sarbanes-Oxley Act of 2002.

Exhibit 12.2 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Donald Munoz, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material f

Section 1350 Certification of Chief Executive Officer, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002.

Exhibit 13.1 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Hugh S. Griffith, Chief Executive Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company

NuCana Reports Fourth Quarter and Year-End 2022 Financial Results and Provides Business Update Multiple Important Data Readouts Expected in 2023 Well Capitalized with Anticipated Cash Runway into 2025

EX-99.1 Exhibit 99.1 NuCana Reports Fourth Quarter and Year-End 2022 Financial Results and Provides Business Update Multiple Important Data Readouts Expected in 2023 Well Capitalized with Anticipated Cash Runway into 2025 Edinburgh, United Kingdom, April 4, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced financial results for the fourth quarter and year ended December 31, 2022 and prov

Rule 13a-14(a)/15d-14(a) Certification of Chief Executive Officer, as adopted pursuant to §302 of the Sarbanes-Oxley Act of 2002.

Exhibit 12.1 Certification Required by Rule 13a-14(a) or 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Hugh S. Griffith, certify that: 1. I have reviewed this annual report on Form 20-F of NuCana plc; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a materi

As filed with the Securities and Exchange Commission on April 4, 2023 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F

As filed with the Securities and Exchange Commission on April 4, 2023 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

Consent of Ernst & Young LLP

Exhibit 15.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-258941) of NuCana plc and in the related Prospectus, (2) Registration Statement (Form S-8 No. 333-223476) pertaining to both NuCana BioMed Limited Option Share Schemes (Including Management Enterpri

Section 1350 Certification of Chief Financial Officer, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002.

Exhibit 13.2 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 I, Donald Munoz, Chief Financial Officer of NuCana plc (the “Company”), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge: 1. The Annual Report on Form 20-F of the Company for

Technical Board of Appeal of the European Patent Office Issues Oral Ruling that NuCana’s ‘190 Patent is Not Valid Ruling Has No Impact on NuCana’s Anti-Cancer ProTide Patents

EX-99.1 Exhibit 99.1 Technical Board of Appeal of the European Patent Office Issues Oral Ruling that NuCana’s ‘190 Patent is Not Valid Ruling Has No Impact on NuCana’s Anti-Cancer ProTide Patents Munich, Germany, March 24, 2023 (GLOBE NEWSWIRE) - NuCana plc (NASDAQ: NCNA) announced that, following a hearing on March 24, 2023, the Technical Board of Appeal (the “TBA”) of the European Patent Office

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2023 (Commission File No. 001-38215) NUCANA PLC

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal executive offi

NCNA / NuCana plc / Griffith Hugh - SC 13G/A Passive Investment

SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 5)* NUCANA PLC (Name of Issuer) Ordinary Shares (Title of Class of Securities) 67022C106 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which thi

NCNA / NuCana plc / Capital International Investors - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 3 )* NuCana PLC (Name of Issuer) Ordinary Shares (Title of Class of Securities) 67022C106 (CUSIP Number) December 30, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to desig

NCNA / NuCana plc / BAILLIE GIFFORD & CO Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 NUCANA PLC (Amendment No.2) - (Name of Issuer) Ordinary Shares - (Title of Class of Securities) 67022C106 - (CUSIP Number) 30 December 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2023 (Commission File No. 001-38215) N

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exec

NuCana Regains Compliance with Nasdaq Minimum Bid Price Requirement

EX-99.1 Exhibit 99.1 NuCana Regains Compliance with Nasdaq Minimum Bid Price Requirement Edinburgh, United Kingdom, January 23, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA), (“NuCana” or the “Company”), announced that it has received a written notification (the “Notification Letter”) from the Listing Qualifications Department of the Nasdaq Stock Market, LLC (“Nasdaq”) informing the Company th

NuCana Announces Receipt of NASDAQ Notice

EX-99.1 2 d420113dex991.htm EX-99.1 Exhibit 99.1 NuCana Announces Receipt of NASDAQ Notice Edinburgh, United Kingdom, January 6, 2023 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced that it received written notification (the “Notification Letter”) from The Nasdaq Stock Market LLC (“Nasdaq”) dated January 3, 2023, indicating that, based upon a closing bid price of less than $1.00 per share f

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2023 (Commission File No. 001-38215) N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2023 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant?s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant?s principal executiv

NuCana Reports Third Quarter 2022 Financial Results and Provides Business Update Multiple Data Readouts on Track for the Remainder of 2022 and the First Half of 2023 Well Capitalized with Anticipated Cash Runway into 2025

EX-99.3 Exhibit 99.3 NuCana Reports Third Quarter 2022 Financial Results and Provides Business Update Multiple Data Readouts on Track for the Remainder of 2022 and the First Half of 2023 Well Capitalized with Anticipated Cash Runway into 2025 Edinburgh, United Kingdom, November 16, 2022 (GLOBE NEWSWIRE) – NuCana plc (NASDAQ: NCNA) announced financial results for the third quarter ended September 3

NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2022 2021 2022 2021 (in thousands, except per share data) £ £ £ £ Research and development exp

EX-99.1 Exhibit 99.1 NUCANA PLC UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS For the Three Months Ended September 30, For the Nine Months Ended September 30, Notes 2022 2021 2022 2021 (in thousands, except per share data) £ £ £ £ Research and development expenses (7,386 ) (8,971 ) (23,238 ) (26,200 ) Administrative expenses (1,715 ) (2,277 ) (5,756 ) (6,456 ) Net foreign exchange gain

For the Three Months Ended September 30,

EX-99.2 Exhibit 99.2 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS You should read the following discussion and analysis of financial condition and results of operations together with the unaudited condensed consolidated financial statements and the related notes to those statements included as Exhibit 99.1 to this Report on Form 6-K submitted to the Securit

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2022 (Commission File No. 001-38215)

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2022 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant’s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant’s principal exe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2022 (Commission File No. 001-38215) N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2022 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant?s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant?s principal executiv

NuCana Presents Positive Data on NUC-3373 at the 34th EORTC-NCI-AACR Annual Meeting 2022 NUC-3373 Potentiates Immunogenic Activity in Lung Cancer Cells Pembrolizumab Activity Increased by NUC-3373 in Lung Cancer Cells NuCana has Initiated the NuTide:

Exhibit 99.1 NuCana Presents Positive Data on NUC-3373 at the 34th EORTC-NCI-AACR Annual Meeting 2022 NUC-3373 Potentiates Immunogenic Activity in Lung Cancer Cells Pembrolizumab Activity Increased by NUC-3373 in Lung Cancer Cells NuCana has Initiated the NuTide:303 Study of NUC-3373 in Combination with Pembrolizumab or Docetaxel Barcelona, Spain, October 26, 2022 (GLOBE NEWSWIRE) ? NuCana plc (NA

NuCana Presents Favorable Data on NUC-3373 at the European Society of Medical Oncology (ESMO) Annual Meeting 2022 NUC-3373 Demonstrates Promising Anti-Tumor Activity and Safety in Combination with Oxaliplatin (NUFOX) and Irinotecan (NUFIRI) in Heavil

Exhibit 99.1 NuCana Presents Favorable Data on NUC-3373 at the European Society of Medical Oncology (ESMO) Annual Meeting 2022 NUC-3373 Demonstrates Promising Anti-Tumor Activity and Safety in Combination with Oxaliplatin (NUFOX) and Irinotecan (NUFIRI) in Heavily Pre-Treated Colorectal Cancer Patients Randomized Study of NUFIRI vs. FOLFIRI in Second-Line Colorectal Cancer Patients Initiated Paris

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2022 (Commission File No. 001-38215)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2022 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant?s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant?s principal execut

NuCana Presents Promising Data on NUC-7738 at the European Society of Medical Oncology (ESMO) Annual Meeting 2022 NUC-7738 Demonstrates Encouraging Anti-Tumor Activity and a Favorable Safety Profile Across a Variety of Solid Tumors NUC-7738 Monothera

Exhibit 99.1 NuCana Presents Promising Data on NUC-7738 at the European Society of Medical Oncology (ESMO) Annual Meeting 2022 NUC-7738 Demonstrates Encouraging Anti-Tumor Activity and a Favorable Safety Profile Across a Variety of Solid Tumors NUC-7738 Monotherapy and Combination with Pembrolizumab to be Investigated in Phase 2 Paris, France, September 12, 2022 (GLOBE NEWSWIRE) - NuCana plc (NASD

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2022 (Commission File No. 001-38215)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2022 (Commission File No. 001-38215) NUCANA PLC (Translation of registrant?s name into English) 3 Lochside Way Edinburgh EH12 9DT United Kingdom (Address of registrant?s principal execut

NuCana Announces Presentations at the European Society for Medical Oncology (ESMO) Congress 2022

Exhibit 99.1 NuCana Announces Presentations at the European Society for Medical Oncology (ESMO) Congress 2022 Edinburgh, United Kingdom, September 6, 2022 (GLOBE NEWSWIRE)?NuCana plc (NASDAQ: NCNA) announced two presentations at the European Society for Medical Oncology (ESMO) Congress 2022 being held September 9-13, 2022 at the Paris Expo Porte de Versailles in Paris, France. The details of NuCan