Result of upsized oversubscribed BookBuild Offer

Use of net proceeds from the Fundraising:

o Phase 2a clinical trial for POLB 001, targeting prevention of cancer immunotherapy-induced Cytokine Release Syndrome (CRS)

o Oral GLP-1 proof-of-concept clinical trial

o Cash runway extended through to 2027

Poolbeg Pharma plc (AIM: POLB, 'Poolbeg Pharma' or the 'Company'), a clinical-stage biopharmaceutical company focussed on the development of innovative medicines to address unmet medical needs, announces that, further to the announcements made on 20 May 2025, regarding the proposed BookBuild Offer (the "BookBuild Offer Announcement"), and on 22 May 2025, regarding the increased size of the BookBuild Offer to £150,000, and, following the closing of the BookBuild Offer on 22 May 2025, 6,000,000 BookBuild Offer Shares will be issued at 2.5 pence per BookBuild Offer Share, conditionally raising gross proceeds for the Company of £150,000.

In aggregate, following the closing of the BookBuild Offer, together with the previously announced Placing and Subscription, the Company has conditionally raised total gross proceeds of £4.865 million.

The BookBuild Offer was oversubscribed and allocations were therefore made to shareholders applying the principles of soft pre-emption. Shareholders whose orders matched or exceeded their soft pre-emptive allowance received 100 per cent of their allowance, with all orders in excess of the allowance scaled back equally.

Capitalised terms not defined in this announcement (this "Announcement") have the meanings given to them in the BookBuild Offer Announcement.

The BookBuild Offer is subject to the passing of certain resolutions at a general meeting of the Company to be held at the offices of DAC Beachcroft LLP at The Walbrook Building, 25 Walbrook, London, England, EC4N 8AF, UK at 2.00 p.m. on 23 June 2025 and conditional upon, amongst other things, the New Ordinary Shares being admitted to trading on the AIM market ("AIM") operated by London Stock Exchange plc (the "London Stock Exchange") ("Admission").

Admission, settlement and dealings

Application will be made to the London Stock Exchange for the BookBuild Offer Shares to be admitted to trading on AIM.

Admission is expected to take place at 8.00 a.m. on 25 June 2025 and dealings in the BookBuild Offer Shares are expected to commence at 8.00 a.m. on 25 June 2025 or, in each case, such later time and/or date as Shore Capital and the Company agree (being in any event no later than 8.00 a.m. on 23 July 2025).

The BookBuild Offer Shares, when issued, will be credited as fully paid and will rank pari passu in all respects with the existing Ordinary Shares, including the right to receive all dividends and other distributions declared, made or paid after the date of issue.

Total Voting Rights

Following Admission of the 197,200,000 New Ordinary Shares (being the Placing Shares, the Subscription Shares, the BookBuild Offer Shares and the Fee Shares), the total issued capital of the Company will consist of 697,200,000 Ordinary Shares with voting rights. The Company does not hold any Ordinary Shares in treasury. Therefore, the total number of voting rights in the Company following Admission will be 697,200,000 and this figure may be used by shareholders in the Company as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the share capital of the Company under the FCA's Disclosure Guidance and Transparency Rules.