Employee Long Term Incentive Plan and Issue of Equity

Cambridge, UK, 22 July 2025 - 4basebio PLC (AIM: 4BB), an innovation-led provider of novel synthetic DNA products and a non-viral, thermostable nucleic acid delivery platform announces that, pursuant to the Employees Benefit Trust (“EBT”) operated by Fiduchi Trustees (UK) Limited, the EBT has been awarded 29,125 ordinary shares of EUR€1.00 each in the Company (“EBT Shares”) at £9.85 per ordinary share, being the closing mid-market price on 7 July 2025.

As announced on 18 July 2024, the EBT was established as part of the employee long-term incentive plan and is a discretionary trust for the benefit of employees of the Company.

The Directors approved the issue of the EBT shares on 18 July 2025. The next allocation is expected to take place during July 2026 and the market will be updated at that time.

Following the settlement of the award of the EBT Shares, the EBT will hold a total of 53,643 shares in the Company, equivalent to 0.19 per cent. of the Company’s enlarged issued share capital.

Issue of Equity and Admission Total Voting Rights

The EBT Shares will be fully paid and will rank pari passu in all respects with the existing ordinary shares of the Company, including, without limitation, the right to receive all dividends and other distributions declared, made or paid after the date of issue.

Application has been made for the EBT Shares to be admitted to trading on AIM (“Admission”). Admission and settlement of the EBT Shares is expected to take place at 8.00 a.m. on 23 July 2025.

Following Admission, the total number of ordinary shares in issue will be 15,538,518. The Company does not hold any ordinary shares in treasury. Therefore, the total number of ordinary shares with voting rights will be 15,538,518. 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 Financial Conduct Authority's Disclosure and Transparency Rules.