Company: NCNA
Filing Date: 2025-04-24
Form Type: F-1
Source: 0001193125-25-092131
Chunk: 113

Company: NuCana plc
Filing Date: 2025-04-24
Form: F-1
Chunk 113
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 by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the
opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be
governed by the final adjudication of such issue.

(c) The undersigned registrant hereby undertakes that:

(1) That for purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part
of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4), or 497(h) under the Securities Act shall be deemed to be part of this registration statement
as of the time it was declared effective.

(2) That for the purpose of determining any liability under the Securities Act, each
post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide
offering thereof.

II-5

SIGNATURES Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form F-1and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Edinburgh, United Kingdom, on April 23, 2025.

| NUCANA, PLC |     |                                |
| By:         |     | /s/ Hugh S. Griffith           |
|             |     | Name: Hugh S. Griffith         |
|             |     | Title: Chief Executive Officer |

POWER OF ATTORNEY KNOW ALL BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Hugh S. Griffith and Ian Webster, and each of them, as his true and lawful attorneys-in-factand agents, each with the full power of substitution, for him and in his name, place or stead, in any and all capacities, to sign any and all amendments to this registration statement (including post-effective amendments), and to sign any registration statement for the same offering covered by this registration statement that is to be effective upon filing pursuant to Rule 462(b) promulgated