Equity fundraise of £16 million

The net proceeds of the Placing provide additional working capital to progress the Company's R&D programs into 2H 2026 including progressing the faridoxorubicin Phase 1b trial and planned initiation of the FAP-EXd Phase Ia trial. Completion of the Placing will satisfy the remaining conditions to the Amendments to the Convertible Bond terms, as announced on 29 August 2025 (as defined in RNS No. 1385X) (the "Bond Amendments RNS"). The Company therefore confirms that the quarterly repayment and interest of the Convertible Bond (as defined in the Bond Amendments RNS) due today will be paid in cash.

The following Amendments to the Convertible Bond will take effect upon completion of the Placing (with capitalised terms having the definitions given in the Bond Amendments RNS):

• Quarterly Convertible Bond repayments and interest in respect of 20 January 2026 and 20 April 2026 payment dates will be deferred until 20 October 2027 (together, the "Deferred Repayments").
• Upon the earlier of (i) the date on which the Company publishes the data readouts of its Phase 1b trials of faridoxorubicin (FAP-Dox, AVA6000) in triple negative breast cancer and (ii) 30 June 2026, the Bondholder will have the right to accelerate the satisfaction (in cash or shares) of one of both the Deferred Repayments and in addition, from 1 October 2026, at any time accelerate the satisfaction of the quarterly repayments on the Convertible Bond, subject to a maximum of one acceleration per quarter.
• The conversion price of the Convertible Bond is to be set at 75.0 pence having previously been set at 88.72 pence under the terms of the reset conversion price as announced on 22 April 2024. The relevant share settlement price in relation to the quarterly repayments and interest remains calculatable based on the then prevailing VWAP.

The Company will continue to progress faridoxorubicin (AVA6000) into 2026, and expects to progress FAP-EXd (AVA6103) into a Phase 1 trial (subject to receipt of an IND from the US Food & Drug Administration) and advance the development of the Company's Dual Payload Technology (AVA6207) with the net proceeds of the Placing extending the Company's cash runway into H2 2026.

Christina Coughlin, CEO of Avacta commented:

"We are continuing to make good progress across all our programs. Our faridoxorubicin trial is gaining momentum, with Phase 1a data presented this weekend at the European Society for Medical Oncology (ESMO) meeting demonstrating a disease control rate in patients treated of 91%.

"Meanwhile, the FAP-EXd (AVA6103) asset is advancing towards clinical development. Our recently revealed dual payload platform is also pioneering how peptide drug conjugates (PDCs) can be utilized for dual payload peptide drug delivery.

"FAP-EXd is on track to enter clinical development in Q1 2026 and is generating interest from a number of potential partners. Importantly, the funds raised allow Avacta to maintain control of this promising asset, allowing us to maximize potential value, while supporting our broader pipeline of programs.

Background to and information on the fundraise

The Placing has been conducted by Zeus Capital Limited ("Zeus") as sole bookrunner.

The Placing

The Placing comprises the issue of 25,396,806 Placing Shares at the Issue Price to conditionally raise approximately £16 million (before expenses) for the Company.

The Placing Shares will rank pari passu with the existing ordinary shares of 10 pence each in the capital of the Company (the "Ordinary Shares") in issue at the time of admission of the Placing Shares to trading on AIM ("Admission") and will represent approximately 5.8 per cent. of the issued ordinary share capital of the Company immediately following Admission.

The Company and Zeus have entered into a placing agreement (the "Placing Agreement"). Pursuant to the terms of the Placing Agreement, Zeus as agent for the Company, has conditionally agreed to use its reasonable endeavours to procure subscribers for the Placing Shares. Zeus has conditionally placed the Placing Shares with certain investors at the Issue Price.

The Placing Agreement contains certain warranties and indemnities from the Company in favour of Zeus. The Placing is not being underwritten by Zeus nor any other person.

The Placing is conditional upon, amongst other things, the Placing Agreement not having been terminated in accordance with its terms and Admission becoming effective.

Admission and total voting rights

Application will be made to the London Stock Exchange for the Admission of the Placing Shares, which is expected to occur at or around 8.00 am on 3 November 2025.

Following Admission, the Company's enlarged issued ordinary share capital will be 436,445,681 Ordinary Shares. This figure may be used by holders of Ordinary Shares ("Shareholders") 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 Guidance and Transparency Rules.

Conditions relating to the Placing

The Placing is conditional, inter alia, upon:

• the Placing Agreement becoming unconditional in all respects (save for Admission occurring) and not having been terminated in accordance with its terms; and
• Admission becoming effective by no later than 8.00 a.m. on 3 November 2025 (or such later time and/or date as the Company and Zeus may agree (being not later than 8.00 a.m. on 10 November 2025)).

Accordingly, if such conditions are not satisfied or, if applicable, waived, the Placing will not proceed.

Issue Price

The Issue Price represents a discount of approximately 8.7 per cent. to the closing middle market price on 17 October 2025, being the last practicable date prior to the publication of this announcement.

Related Party Transaction

Richard Hughes, a director of the Company, is an associate of Zeus as defined under the AIM Rules for Companies. Zeus is therefore a related party of the Company pursuant to the AIM Rules and the payment of a 5 per cent. commission on the value of the Placing Shares placed by Zeus, being £800,000 and a corporate finance fee of £50,000 (together the "Zeus Fees") pursuant to the terms of the Placing Agreement, are deemed to be a related party transaction. The directors of the Company (other than Richard Hughes who is an associate of Zeus Capital) consider, having consulted with the Company's nominated adviser, Peel Hunt LLP, that the Zeus Fees are fair and reasonable insofar as Shareholders are concerned.

Notes:

References to times in this announcement are to London, UK time unless otherwise stated.

The times and dates mentioned throughout this announcement may be adjusted by the Company in which event the Company will make an appropriate announcement to a Regulatory Information Service giving details of any revised dates and the details of the new times and dates will be notified to the London Stock Exchange and, where appropriate, Shareholders. Shareholders may not receive any further written communication.

This announcement should be read in its entirety. In particular, the information in the "Important Notices" section of this announcement should be read and understood.

Information to Distributors

UK Product Governance Requirements

Solely for the purposes of the Product Governance requirements contained within 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 PlacingShares have been subject to a product approval process, which has determined that the Placing Shares are: (i) compatible with an end target market of investors who meet the criteria of professional clients and eligible counterparties, each as defined in the FCA Handbook Conduct of Business Sourcebook; and (ii) eligible for distribution through all distribution channels as are permitted by UK Product Governance Requirements (the "UK Target Market Assessment"). Notwithstanding the UK Target Market Assessment, distributors should note that: the price of the Placing Shares may decline and investors could lose all or part of their investment; the Placing Shares offer no guaranteed income and no capital protection; and an investment in the Placing Shares is compatible only with investors who do not need a guaranteed income or capital protection, who (either alone or in conjunction with an appropriate financial or other adviser) are capable of evaluating the merits and risks of such an investment and who have sufficient resources to be able to bear any losses that may result therefrom.

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

EU Product Governance Requirements

Solely for the purposes of the product governance requirements contained within (a) EU Directive 2014/65/EU on markets in financial instruments, as amended ("MiFID II"), (b) Articles 9 and 10 of Commission Delegated Directive (EU) 2017/593 supplementing MiFID II and (c) local implementing measures (together the "EU Product Governance Requirements") and disclaiming all and any liability, whether arising in tort, contract or otherwise, which any "manufacturer" (for the purposes of the EU Product Governance Requirements) may otherwise have with respect thereto, the Placing Shares have been subject to product approval process, which has determined that the Placing Shares are: (i) compatible with an end target market of (a) investors who meet the criteria of professional clients and (b) eligible counterparties, each as defined in MiFID II; and (ii) eligible for distribution through all distribution channels as are permitted by EU Product Governance Requirements (the "EU Target Market Assessment"). Notwithstanding the EU Target Market Assessment, distributors should note that: the price of the Placing Shares may decline and investors could lose all or part of their investment; the Placing Shares offer no guaranteed income and no capital protection; and an investment in the Placing Shares is compatible only with investors who do not need a guaranteed income or capital protection, who (either alone or in conjunction with an appropriate financial or other adviser) are capable of evaluating the merits and risks of such an investment and who have sufficient resources to be able to bear any losses that may result therefrom.

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