Notice of Interim Results and Investor Presentation

Change of Date, Time and Location of ESMO Abstract Presentation

LONDON AND PHILADELPHIA - September 15, 2025 -  Avacta Group plc (AIM: AVCT) a life sciences company developing innovative, targeted oncology drugs, confirms it will announce its unaudited interim results for the six months ended June 30, 2025 ("HY25"), on September 30, 2025.

Christina Coughlin, Chief Executive Officer and Brian Hahn, Chief Financial Officer will also deliver a live presentation via Investor Meet Company at 14:00 BST on the day.

The presentation is open to all existing and potential shareholders.

Investors can sign up to Investor Meet Company for free and add to meet AVACTA GROUP PLC via: AVCT - AVACTA GROUP PLC | Investor Meet Company

Investors who already follow Avacta on the Investor Meet Company platform will automatically be invited.

Questions can be submitted pre-event via the Investor Meet Company dashboard up until September 30 09:00 BST, or at any time during the live presentation.

The Company will also post the results presentation on its website at the following page: https://avacta.com/investors/investor-resources/.

ESMO Congress Update

The Company confirms that the date, time and location of the abstract being presented at the European Society for Medical Oncology (ESMO) Congress, taking place from October 17-21, 2025, has changed. The updated details are included below:

Title: A Phase I trial of FAP-Dox (AVA6000), a Fibroblast Activation Protein (FAP)-released and tumor microenvironment (TME)-targeted doxorubicin peptide drug conjugate in patients with FAP-positive solid tumors

Session Title: Developmental Therapeutics

Session Date and Time: 19 October, 12.00-12.45

Location: Hall 25

Abstract Presentation Number: 964P

Speaker: William D. Tap

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For further information from Avacta, please contact:

About Avacta - https://avacta.com/

Avacta Therapeutics is a clinical-stage life sciences company expanding the reach of highly potent cancer therapies with the pre|CISION^® platform. pre|CISION^® is a proprietary payload delivery system based on a tumor-specific protease (fibroblast activation protein or FAP) that is designed to concentrate highly potent payloads in the tumor microenvironment while sparing normal tissues. Our innovative pipeline consists of pre|CISION^® peptide drug conjugates (PDC) or Affimer^® drug conjugates (AffDC) that leverage the tumor-specific release mechanism, providing unique benefits over traditional antibody drug conjugates.

About the pre|CISION^® Platform

The pre|CISION^® platform comprises an anticancer payload conjugated to a proprietary peptide that is a highly specific substrate for fibroblast activation protein (FAP) which is upregulated in most solid tumors compared with healthy tissues. The pre|CISION^® platform harnesses this tumor specific protease to cleave pre|CISION^® peptide drug conjugates and pre|CISION^® antibody/Affimer^® drug conjugates in the tumor microenvironment, thus releasing active payload in the tumor and reducing systemic exposure and toxicity, allowing dosing to be optimized to deliver the best outcomes for patients.