Other Events

On August 13, 2026, NuCana plc (the “Company”) issued a press release announcing its second quarter 2026 financial results. The Company’s unaudited condensed consolidated financial statements as of June 30, 2026 are attached as Exhibit 99.1 and are incorporated by reference herein. The Company’s Management’s Discussion and Analysis of Financial Condition and Results of Operations is attached as Exhibit 99.2 hereto and is incorporated by reference herein. The press release is attached as Exhibit 99.3 hereto and is incorporated by reference herein.

The information in this Report on Form 6-K and in the attached Exhibits 99.1 and 99.2 shall be deemed to be incorporated by reference into the registration statements on Form F-3, as amended (File Number 333-281576) and Form S-8 (File Number 333-223476, File Number 333-248135 and File Number 333-294466), and related prospectuses, as such registration statements and prospectuses may be amended from time to time, and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

The information in the attached Exhibit 99.3 is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as otherwise set forth herein or as shall be expressly set forth by specific reference in such a filing.

Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereto duly authorized.

Date: August 13, 2026