Company: NCNA
Filing Date: 2025-06-02
Form Type: 6-K
Source: 0001193125-25-133350
Chunk: 1

Company: NuCana plc
Filing Date: 2025-06-02
Form: 6-K
Chunk 1
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 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

| Exhibit 
 99.1    
 99.2    |     | Description                                                                                                                              
 Unaudited Condensed Consolidated Financial Statements as of March 31, 2025 and for the Three Months Ended March 31, 2025 and 2024        
 Management’s Discussion and Analysis of Financial Condition and Results of Operations for the Three Months Ended March 31, 2025 and 2024 |
|:--------|:----|:-----------------------------------------------------------------------------------------------------------------------------------------|
| 99.3    |     | Supplemental Risk Factors                                                                                                                |
| 99.4    |     | Press Release dated June 2, 2025                                                                                                         |

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.

| NuCana plc |     |                         |
| By:        |     | /s/ Hugh S. Griffith    |
| Name:      |     | Hugh S. Griffith        |
| Title:     |     | Chief Executive Officer |

Date: June 2, 2025