Company: NCNA
Filing Date: 2025-08-20
Form Type: 6-K
Source: 0001193125-25-184104
Chunk: 0

Company: NuCana plc
Filing Date: 2025-08-20
Form: 6-K
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

#### FORM6-K

### REPORT OF FOREIGN PRIVATE ISSUER

#### PURSUANT TORULE 13a-16 OR 15d-16

#### OF THE SECURITIES EXCHANGE ACT OF 1934

#### For the month of August2025
<div align='center'>**(Commission**</div>

#### File No. 001-38215)

### NUCANA PLC
<div align='center'>**(Translation of registrant’s name into English)**</div>

#### 3 Lochside Way

#### Edinburgh EH12 9DT

#### United Kingdom
<div align='center'>**(Address of registrant’s principal executive office)**</div>

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

<div align='center'>Form 20-F ☒ Form 40-F ☐</div>

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101 (b) (1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101 (b) (7): ☐

Other Events On August 20, 2025, NuCana plc (the “Company”) issued a press release announcing its second quarter 2025 financial results. The Company’s unaudited condensed consolidated financial statements as of June 30, 2025 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 hereto as Exhibit 99.2, 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 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 333-223476and File Number 333-248135),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be amended from time to time, and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or