General Information	6 Months Ended
Jun. 30, 2025
Disclosure Of General Information About Financial Statements [Abstract]
General information	1. General information NuCana plc (“NuCana” or the “Company”) is a clinical-stage biopharmaceutical company developing a portfolio of new medicines to treat patients with cancer. NuCana is harnessing the power of phosphoramidate chemistry to generate new medicines called ProTides. These compounds have the potential to improve cancer treatment by enhancing the efficacy and safety of several current standards of care. The Company has had American Depository Shares (“ADSs”) registered with the US Securities and Exchange Commission (“SEC”) and has been listed on Nasdaq since October 2, 2017. From November 9, 2023 the Company transferred its listing to The Nasdaq Capital Market. On April 16, 2024, the Company effected a ratio change of its ADSs to its ordinary shares from one ADS representing one ordinary share, to one ADS representing 25 ordinary shares. On August 11, 2025, the Company effected a ratio change of its ADSs to its ordinary shares from one ADS representing 25 ordinary shares, to one ADS representing 5,000 ordinary shares. The Company is incorporated in England and Wales and domiciled in the United Kingdom. The Company’s registered office is located at 77/78 Cannon Street, London EC4N 6AF, United Kingdom and its principal place of business is located at 3 Lochside Way, Edinburgh, EH12 9DT, United Kingdom. The Company has three wholly owned subsidiaries, NuCana, Inc., NuCana Limited and NuCana BioMed Trustee Company Limited (together referred to as the “Group”). The financial information presented in these unaudited condensed consolidated financial statements does not constitute the Group’s statutory accounts within the meaning of section 434 of the U.K. Companies Act 2006. The Group’s statutory accounts for the year ended December 31, 2024 have been reported on by the Company’s auditor, and delivered to the Registrar of Companies. The report of the auditor was (i) unqualified and (ii) did not include a reference to any matters to which the auditors drew attention by way of emphasis without qualifying their report. However, the report of the auditor did include a material uncertainty related to going concern disclosure.

NuCana plc (“NuCana” or the “Company”) is a clinical-stage biopharmaceutical company developing a portfolio of new medicines to treat patients with cancer. NuCana is harnessing the power of phosphoramidate chemistry to generate new medicines called ProTides. These compounds have the potential to improve cancer treatment by enhancing the efficacy and safety of several current standards of care.

The Company has had American Depository Shares (“ADSs”) registered with the US Securities and Exchange Commission (“SEC”) and has been listed on Nasdaq since October 2, 2017. From November 9, 2023 the Company transferred its listing to The Nasdaq Capital Market. On April 16, 2024, the Company effected a ratio change of its ADSs to its ordinary shares from one ADS representing one ordinary share, to one ADS representing 25 ordinary shares. On August 11, 2025, the Company effected a ratio change of its ADSs to its ordinary shares from one ADS representing 25 ordinary shares, to one ADS representing 5,000 ordinary shares.

The Company is incorporated in England and Wales and domiciled in the United Kingdom. The Company’s registered office is located at 77/78 Cannon Street, London EC4N 6AF, United Kingdom and its principal place of business is located at 3 Lochside Way, Edinburgh, EH12 9DT, United Kingdom.

The Company has three wholly owned subsidiaries, NuCana, Inc., NuCana Limited and NuCana BioMed Trustee Company Limited (together referred to as the “Group”).

The financial information presented in these unaudited condensed consolidated financial statements does not constitute the Group’s statutory accounts within the meaning of section 434 of the U.K. Companies Act 2006.

The Group’s statutory accounts for the year ended December 31, 2024 have been reported on by the Company’s auditor, and delivered to the Registrar of Companies. The report of the auditor was (i) unqualified and (ii) did not include a reference to any matters to which the auditors drew attention by way of emphasis without qualifying their report. However, the report of the auditor did include a material uncertainty related to going concern disclosure.