SCHEDULE 13D/A 0001193125-22-218663 0001527166 XXXXXXXX LIVE 2 Ordinary Shares, nominal value (pound)0.04 per share 04/18/2025 false 0001709626 67022C205 NuCana plc

3 Lochside Way Edinburgh X0 EH12 9DT

Jeffrey Ferguson (202) 729-5626 The Carlyle Group 1001 Pennsylvania Avenue, NW,Suite 220 S Washington DC 20004 0001527166 N The Carlyle Group Inc. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 CO 0001548626 N Carlyle Holdings I GP Inc. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 CO 0001548627 N Carlyle Holdings I GP Sub L.L.C. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 OO Limited Liability Company 0001548628 N Carlyle Holdings I L.P. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 PN 0001790577 N CG Subsidiary Holdings L.L.C. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 OO Limited Liability Company 0000933790 N TC Group, L.L.C. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 OO Limited Liability Company 0001354120 N Carlyle Investment Management L.L.C. OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 OO Limited Liability Company 0001941860 N Carlyle Genesis UK LLC OO N DE 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 OO Limited Liability Company 0001397144 N Abingworth LLP OO N X0 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 PN 0001688313 N Abingworth Bioventures VII LP OO N X0 0.00 3430062.00 0.00 3430062.00 3430062.00 N 2.4 PN Ordinary Shares, nominal value (pound)0.04 per share NuCana plc 3 Lochside Way Edinburgh X0 EH12 9DT This Amendment No. 2 to Schedule 13D ("Amendment No. 2") amends and supplements the Schedule 13D originally filed with the United States Securities and Exchange Commission on September 28, 2020 (as amended to date, the "Schedule 13D"), relating to the Ordinary Shares, nominal value (pound)0.04 per share (the "Ordinary Shares"), of NuCana, plc, a public limited company incorporated in England and Wales (the "Issuer"). Capitalized terms used herein without definition shall have the meanings set forth in the Schedule 13D. Item 5 of the Schedule 13D is hereby amended and restated in its entirety as follows: The information contained on the cover pages is incorporated by reference into this Item 5. The percentage of Ordinary Shares beneficially owned and reported herein is based on 142,037,199 Ordinary Shares outstanding as of December 31, 2024, as disclosed in the Issuer's annual report on Form 20-F filed on March 20, 2025. The securities reported herein include (i) 3,333,333 Ordinary Shares represented by American Depository Shares held of record by Abingworth Bioventures VII LP, (ii) 96,189 Ordinary Shares underlying stock options exercisable within 60 days as of the date hereof, and (iii) 540 Ordinary Shares represented by American Depository Shares held of record by Bali Muralidhar for the benefit of Abingworth Bioventures VII LP and which may be deemed to be beneficially owned by Abingworth Bioventures VII LP. The Carlyle Group Inc., which is a publicly traded entity listed on Nasdaq, is the sole shareholder of Carlyle Holdings I GP Inc., which is the sole member of Carlyle Holdings I GP Sub L.L.C., which is the general partner of Carlyle Holdings I L.P., which, with respect to the securities reported herein, is the managing member of CG Subsidiary Holdings L.L.C., which is the managing member of TC Group, L.L.C., which is the managing member of Carlyle Investment Management, L.L.C., which is the sole member of Carlyle Genesis UK LLC, which is the principal member of Abingworth LLP. Abingworth Bioventures VII LP has delegated to Abingworth LLP all investment and dispositive power over the securities held of record by Abingworth Bioventures VII LP. Accordingly, each of the foregoing entities may be deemed to share beneficial ownership of the securities held of record and beneficially owned by Abingworth Bioventures VII LP, but each disclaims beneficial ownership of such securities. The information contained on the cover pages is incorporated by reference into this Item 5. During the past 60 days, the Reporting Persons have not effected any transactions with respect to the Ordinary Shares. None. As of March 20, 2025, the Reporting Persons ceased to be the beneficial owners of more than five percent of the outstanding Ordinary Shares. Item 7 of the Schedule 13D is hereby amended and supplemented as follows: Exhibit 3: Power of Attorney. The Carlyle Group Inc. /s/ Anne Frederick, attorney-in-fact 04/18/2025 Carlyle Holdings I GP Inc. /s/ Anne Frederick, attorney-in-fact 04/18/2025 Carlyle Holdings I GP Sub L.L.C. By: Carlyle Holdings I GP Inc., its sole member, /s/ Anne Frederick, attorney-in-fact 04/18/2025 Carlyle Holdings I L.P. /s/ Anne Frederick, attorney-in-fact 04/18/2025 CG Subsidiary Holdings L.L.C. /s/ Anne Frederick, attorney-in-fact 04/18/2025 TC Group, L.L.C. /s/ Anne Frederick, attorney-in-fact 04/18/2025 Carlyle Investment Management L.L.C. /s/ Anne Frederick, attorney-in-fact 04/18/2025 Carlyle Genesis UK LLC By: Carlyle Investment Management L.L.C., its sole member, /s/ Anne Frederick, attorney-in-fact 04/18/2025 Abingworth LLP /s/ John Heard 04/18/2025 Abingworth Bioventures VII LP /s/ John Heard 04/18/2025