5 April 2023

Avacta Group plc

("Avacta" and, together with its subsidiary undertakings, the "Group")

First Patient Dosed in Fifth Cohort of AVA6000 Phase Ia Dose Escalation Study

Avacta Group plc (AIM: AVCT), a life sciences company developing innovative, targeted oncology drugs and powerful diagnostics, announces that the first patient has been dosed in the fifth cohort of the first-in-human phase I trial (ALS-6000-101) of AVA6000. This follows the approval of an amended clinical trial protocol by the Medical and Healthcare Products Regulatory Agency (MHRA) to allow for higher levels of dosing.

Avacta's Safety Data Monitoring Committee (SDMC), comprised of clinicians currently recruiting patients, has recommended that the phase Ia dose escalation clinical trial continues to a fifth dose cohort at 250mg/m², following the favourable safety profile of AVA6000 generated in the study to date. Escalation to this level of dosing falls outside of the original clinical trial protocol, and therefore the protocol required amendment and approval by the MHRA, which has now been completed. This continued dose escalation is aimed at identifying a maximum tolerated dose (MTD) necessary to inform the dosing levels for the phase 1b and future studies.

Dr Alastair Smith, Chief Executive Officer of Avacta Group, commented:

"We are very much encouraged by the positive safety and tolerability data emerging from the dose escalation phase 1a study of AVA6000. Following the recommendation from the SDMC, and approval by the MHRA, we are pleased to commence dosing in the fifth patient cohort of this trial.

The recent confirmation of release of active chemotherapy in the tumour tissue and the safety data being generated in the ALS-6000-101 study are providing detailed insights into the pre|CISION™ platform which add significant value to the technology and confirm the tumour targeting potential of the pre|CISION™ platform."

This announcement has been approved for release by Alastair Smith, Chief Executive Officer of Avacta Group plc.

-Ends-

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

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About AVA6000

AVA6000 is a novel form of doxorubicin that has been modified with Avacta's pre|CISION™ FAP-activated delivery platform to improve its safety and therapeutic index. AVA6000 has been designed to limit cell penetration of the drug, and therefore its cell killing effect, until it is specifically activated by fibroblast activation protein α (FAPα) which is in high concentration in many solid tumours compared with healthy tissues. The resulting reduced exposure of healthy tissues to active doxorubicin has the potential to significantly increase its therapeutic index by reducing the incidence of adverse effects, including cardiotoxicity and myelosuppression.

Anthracyclines such as doxorubicin, a generic chemotherapeutic agent, with a market size that is expected to grow to $1.38bn by 2024^[1], are widely used as part of standard of care in several tumour types, but its use is limited by cumulative dose toxicity associated with cardiomyopathy.

[1] https://www.prnewswire.com/news-releases/doxorubicin-market-size-is-expected-to-reach-138-billion-by-2024-grand-view-research-inc-602613665.html

About Avacta Group plc - www.avacta.com

Avacta Group plc is a life sciences company working to improve people's health and well-being through innovative oncology drugs and powerful diagnostics. Operating through two divisions, Diagnostics and Therapeutics, the Group's mission is to provide professionals and consumers with solutions that improve healthcare, fitness and well-being.

Avacta's Therapeutics Division, a clinical stage oncology drug innovator, is building a wholly owned pipeline of novel Affimer^® immunotherapies and pre|CISION™ tumour targeted chemotherapies. This approach is designed to address the lack of a durable response to current cancer immunotherapies experienced by most patients and reduce the severe systemic toxicities caused by chemotherapies. There are five programmes in the pipeline as well as several global research collaborations and licensing partnerships. Avacta's lead programme, AVA6000, is a pre|CISION™ tumour-targeted form of the established chemotherapy doxorubicin. AVA6000 is in Phase I clinical trials in patients with locally advanced or metastatic selected solid tumours.

The Affimer^® platform is an alternative to antibodies that has been designed to address many of the drawbacks of antibodies which, despite their shortcomings, currently dominate the immuno-diagnostics and immuno-therapeutics markets.

The pre|CISION™ tumour targeting platform can be used to modify a chemotherapy in order to selectively release the active drug in tumour tissue thereby reducing the systemic exposure that causes damage to healthy tissues. pre|CISION™ modified chemotherapies are designed to reduce the side effects and improve the overall safety and therapeutic potential of these powerful anti-cancer treatments.

Avacta's Diagnostics Division develops and supplies a broad range of in-vitro diagnostic (IVD) solutions. The Division is growing rapidly through an M&A strategy to deliver a global scale IVD business providing market leading solutions for healthcare professionals and consumers to inform treatment and monitor health and well-being. In October 2022, Avacta acquired Launch Diagnostics which serves the hospital pathology laboratory market in the UK and Europe. Avacta Diagnostic's research and development centre in Wetherby, UK uses its proprietary Affimer^® platform to differentiate immunodiagnostic products to provide marketing leading performance.

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