NuCana (NCNA) 6-K NuCana Presents Data at AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN ISSUER

PURSUANT TO RULE13a-16 OR15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of October 2019

(Commission FileNo. 001-38215)

NUCANA PLC

(Translation of registrant’s name into English)

3 Lochside Way

Edinburgh EH12 9DT

United Kingdom

(Address of registrant’s principal executive office)

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

Form 20-F ☒                     Form40-F ☐

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

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

Other Events

On October 29, 2019, NuCana plc (the “Company”) issued a press release announcing the presentation of interim data from its Phase Ib NuTide:302 study in patients with advanced colorectal cancer and the presentation of data from non-clinical studies ofNUC-7738, which is currently being evaluated in the Phase 1 NuTide:701 study in patients with advanced solid tumors, at theAACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Boston, Massachusetts. The press release is attached as Exhibit 99.1 hereto and is incorporated by reference herein.

The information in the attached Exhibit 99.1 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

99.1 Press Release, dated October 29, 2019.

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, thereunto duly authorized.

NuCana plc
By:	/s/ Donald Munoz
Name: Title:	Donald Munoz Chief Financial Officer

Date: October 29, 2019