Results of Capital Raise

The information contained within this announcement is deemed by the Group to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014 (as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018). Upon the publication of this announcement via the Regulatory Information Service, this inside information is now considered to be in the public domain.

4basebio PLC

(“4basebio” or the “Company”)

Results of Capital Raise

CAMBRIDGE, UK – 15 October 2026 - 4basebio PLC (AIM: 4BB), a specialist in synthetic DNA manufacturing for next-generation genomic medicines and advanced therapies, is pleased to announce that it has conditionally raised gross proceeds of approximately £15.0 million through (i) the placing of 2,664,080 new Ordinary Shares (the “Placing Shares”, comprising 485,436 VCT placing shares and 2,178,644 ordinary placing shares) to institutional investors including certain existing shareholders (the “Placing”), and (ii) subscriptions for 1,025,239 new Ordinary Shares (the “Subscription Shares”) by certain directors and existing shareholders including those pertaining to the Subscription & Set-Off Agreement as defined below (the “Subscription”, and, together with the Retail Offer (as defined below) the “Capital Raise”). The Capital Raise is subject to shareholder approval.

M&G Investment Management Limited (“M&G”), which currently holds 12.62 per cent. of the existing ordinary share capital of the Company, has subscribed for 465,830 Placing Shares. Elevage Medical Technologies LLC, which currently holds 17.16 per cent. of the existing ordinary share capital of the Company, has subscribed for 256,504 Placing Shares. The Participation of the Deutsche Balaton group, which currently holds 32.95 per cent. of the existing ordinary share capital of the Company, in the Capital Raise is described in further detail below under “2Invest Subscription and Set Off”.

Directors and Officers’ Subscriptions

Certain directors and officers of the Company – namely Amy Walker, Richard Bungay, Heikki Lanckriet and Hansjörg Plaggemars – have subscribed for 54,366 Subscription Shares, representing aggregate gross proceeds of £0.3 million pursuant to the Subscription.

2Invest Subscription and Set-off

The Company currently has a fully drawn €25 million loan facility with 2Invest AG, a member of the Deutsche Balaton group (the “Shareholder Loan”). Entities in the Deutsche Balaton group currently hold, in aggregate, 32.95 per cent. of the existing ordinary share capital of the Company. Concurrently with the Placing, 2Invest AG has agreed under the terms of a subscription and set-off agreement dated 15 October 2026 (the “Subscription & Set-Off Agreement”) (i) to subscribe for 194,174 Subscription Shares in cash at the Issue Price, for an aggregate amount of approximately £1 million and (ii) to subscribe for an additional 776,699 Subscription Shares at the Issue Price, for an aggregate amount of approximately £4 million, payment of which shall be satisfied through the set-off against repayment of an equivalent amount of principal and accrued interest outstanding under the Shareholder Loan, reducing the outstanding balance under the Shareholder Loan to the principal sum of €21,083,234[2] (the “2Invest Subscription & Set-Off”). The maturity date of the Shareholder Loan will also be extended by two years to 31 October 2030.

The 2Invest Subscription & Set-Off and the amendment of the Shareholder Loan are conditional upon completion of the Placing and the remainder of the Subscriptions.

Related Party Transaction

The amendment to the Shareholder Loan, pursuant to the Subscription & Set-Off Agreement to allow for the Subscription, is a related party transaction pursuant to Rule 13 of the AIM Rules for Companies (the “Related Party Transaction”).

Hansjörg Plaggemars is a director of the Company and Managing Director of 2Invest AG. As such, the Directors, with the exception of Hansjörg Plaggemars, having consulted with the Company's Nominated Adviser, Cairn Financial Advisers LLP, consider the terms of the Related Party Transaction to be fair and reasonable insofar as the Company’s AIM shareholders are concerned.

Retail Offer

Alongside the Placing and the Subscription, the Company is proposing to raise up to an additional £0.5 million (before expenses) by way of a retail offer via the Bookbuild Platform (the “Retail Offer”). A separate announcement will be made shortly regarding the Retail Offer and its terms and conditions. For the avoidance of doubt the Retail Offer forms no part of the Placing. No part of the Placing is conditional on the Retail Offer proceeding or on any minimum take-up under the Retail Offer.

General Meeting

The Capital Raise is conditional on shareholder approval. Accordingly, the Company will convene a general meeting (the “General Meeting”) at which shareholders will be asked to consider and, if thought fit, pass the required shareholder resolutions approving the grant of new authorities to the Directors to allot the Placing Shares, Subscription Shares and Retail Shares (the “New Shares”) and to disapply statutory pre-emption rights in respect of such allotments (the “Resolutions”).

It is expected that the shareholder circular and notice of General Meeting (the “Shareholder Circular”) will be posted within three Business Days and the General Meeting will be held on or around 6 November 2026. Further details will be announced in due course.

Admission and Total Voting Rights

Following the General Meeting, the Company will make applications for the admission of 2,664,080 Placing Shares, 1,025,239 Subscription Shares and the Retail Shares to trading on AIM (“Admission”).

It is expected that Admission of the VCT Placing Shares will occur at 8.00 a.m. on or around 9 November 2026 (“First Admission”). Admission of the remainder of the New Shares is expected to occur at 8.00 a.m. on or around 10 November 2026, one business day following First Admission (“Second Admission”).

Admission is conditional, inter alia, upon Admission becoming effective, the Placing Agreement not having been terminated and becoming unconditional, and upon the approval of the Resolutions by Shareholders at the General Meeting.

Expected Timetable of Principal Events

INFORMATION TO DISTRIBUTORS

Solely for the purposes of the product governance requirements of Chapter 3 of the FCA Handbook Product Intervention and Product Governance Sourcebook (the "UK Product Governance Requirements"), and disclaiming all and any liability, whether arising in tort, contract or otherwise, which any “manufacturer” (for the purposes of the UK Product Governance Requirements) may otherwise have with respect thereto, the Placing Shares have been subject to a product approval process, which has determined that the Placing Shares are: (i) compatible with an end target market of retail investors and investors who meet the criteria of professional clients and eligible counterparties, each defined in paragraph 3 of the FCA Handbook Conduct of Business Sourcebook; and (ii) eligible for distribution through all permitted distribution channels to professional clients and eligible counterparties (the "Target Market Assessment").

The Target Market Assessment is without prejudice to the requirements of any contractual, legal or regulatory selling restrictions in relation to the offering of the Placing Shares. Furthermore, it is noted that, notwithstanding the Target Market Assessment, the Banks will only procure investors who meet the criteria of professional clients and eligible counterparties.

[1] Assuming that the Retail Offer is subscribed for in full and the maximum number of Retail Shares is issued upon Second Admission.

[2] Assuming Admission occurs on 10 November 2026 and based on the EUR:GBP exchange rate of 1: 0.84514 as derived by Bloomberg on one day prior to the date of this Announcement.