6 April 2023

Avacta Group plc

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

Avacta Opens First Two US Clinical Investigator Sites for AVA6000 Phase 1 Clinical Study

Memorial Sloan Kettering Cancer Center and Fred Hutch Cancer Center now open for patient enrolment to pre|CISION™ lead programme, AVA6000

Avacta Group plc (AIM: AVCT), a life sciences company developing innovative, targeted oncology drugs and powerful diagnostics, announces the opening on 5 April 2023 of the first two clinical investigator sites for the phase 1 clinical trial of AVA6000 under its US Investigational New Drug (IND) Application. The two sites, Memorial Sloan Kettering Cancer Center (MSK) in New York and Fred Hutch Cancer Center in Seattle, are now open for patient enrolment to ALS-6000-101. This is the first-in-human trial of AVA6000, Avacta's lead pre|CISION™ drug candidate for the treatment of soft tissue sarcoma.

Active enrolment has now begun for soft tissue sarcoma patients to the phase 1 clinical trial in the US, led by Dr William D. Tap, Chief of the Sarcoma Medical Oncology Service at MSK, and Dr Lee D. Cranmer, Professor at the Clinical Research Division of Fred Hutch Cancer Center.

The opening of the US phase 1 trial sites for recruitment marks a significant milestone in Avacta's plan to expand AVA6000 clinical studies. A phase 1a dose escalation study is currently underway in the UK and recently begun dosing patients in the fifth cohort at 250 mg/m² as announced on 5 April 2023, following the favourable safety profile of AVA6000 generated in the study to date. The US trial sites will initially contribute patients to the dose escalation phase, while being uniquely positioned to lead the enrolment of soft tissue sarcoma patients in the phase 1b dose expansion stage of the AVA6000 study when this begins. Patients will receive the same doses at each stage of the trial as in the UK.

The Company will provide further updates in respect of the progress of the US phase 1 trial as appropriate.

Neil Bell, Chief Development Officer for Avacta Therapeutics, commented:

"This timely opening of these two key US sites, under the expert direction of Dr Tap and Professor Cranmer, is a major milestone in Avacta's entry strategy into the US with our promising AVA6000 pre|CISION™ lead programme. We share with our US colleagues a clear vision to transform treatment outcomes for patients, and we look forward to working together as we continue to build the clinical evidence base for the safety and tolerability of AVA6000, in addition to the significant 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-

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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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