Publication of Prospectus

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY IN OR INTO ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION

This announcement is an advertisement and not a prospectus. Neither this announcement nor anything contained herein shall form the basis of, or be relied upon in connection with, any offer or commitment whatsoever in any jurisdiction. Investors should not purchase any transferable securities referred to in this announcement except on the basis of information contained in the prospectus (the "Prospectus") in its final form that is published by Hemogenyx Pharmaceuticals plc in connection with the admission of new ordinary shares in the capital of the Company (the "New Ordinary Shares") to listing in equity shares (transition) category of the Official List of the Financial Conduct Authority (the "FCA") and to trading on the main market for listed securities (the "Main Market") of London Stock Exchange plc (the "London Stock Exchange") following conversion of certain convertible loan notes and exercise of certain warrants.

19 November 2025

Hemogenyx Pharmaceuticals plc

("Hemogenyx Pharmaceuticals" or the "Company")

Publication of Prospectus

The Company is pleased to announce today the publication of a Prospectus in relation to the admission of 116,982 new ordinary shares of 0.01 pence each to be issued upon conversion of convertible loan notes issued by the Company on 31 August 2025 (the "Convertible Loan Notes Shares") and 439,629 new ordinary shares of 0.01 pence each to be issued following the exercise of certain of the warrants issued by the Company during 2025 (the "Warrant Shares") (together the "New Ordinary Shares") to listing in the equity shares (transition) category of the Official List of the FCA and to trading on the Main Market of the London Stock Exchange (together, "Admission").

It is expected that Admission will become effective, and unconditional dealings in the New Ordinary Shares will commence on 24 November 2025.

The Prospectus will be available from the Company's registered office at 6 Heddon Street, London W1B 4BT, United Kingdom and online at https://hemogenyx.com (subject to applicable securities laws).

An electronic copy of the Prospectus will also be submitted to the National Storage Mechanism and should be available shortly for inspection at https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

Enquiries:

About Hemogenyx Pharmaceuticals plc

Hemogenyx Pharmaceuticals is a publicly traded company (LSE: HEMO) headquartered in London, with its US operating subsidiaries, Hemogenyx LLC and Immugenyx LLC, located in New York City.

The Company is a clinical stage biopharmaceutical group developing new medicines and treatments to treat blood and autoimmune diseases. Hemogenyx Pharmaceuticals is developing several distinct and complementary product candidates, as well as a platform technology that it uses as engines for novel product development.

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