Avacta Group Regulatory News (AVCT)

This announcement contains inside information for the purposes of Article 7 of the UK version of Regulation (EU) No 596/2014 which is part of UK law by virtue of the European Union (Withdrawal) Act 2018, as amended ("MAR"). Upon the publication of this announcement via a Regulatory Information Service, this inside information is now considered to be in the public domain.

21 June 2023

Avacta Group plc

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

Successful Completion of Fifth Dose Escalation in AVA6000 Phase 1 Clinical Study

Very positive safety profile of AVA6000 continues to be observed in the fifth cohort

Several patients remain on trial in different dose cohorts and continue to receive AVA6000 as their disease has not progressed

Avacta Group plc (AIM: AVCT), a life sciences company developing innovative, targeted oncology drugs and powerful diagnostics, today announces that the fifth dose escalation cohort in the ALS-6000-101 dose escalation Phase 1 clinical trial to evaluate the safety and tolerability of AVA6000 has been completed successfully. The data continue to show a very favourable safety profile for the tumour targeted chemotherapy and several patients in cohort 5 and earlier cohorts remain on treatment as their disease has not progressed.

AVA6000 is a form of doxorubicin that has been chemically modified with Avacta's pre|CISIONTM platform designed to reduce systemic side effects by targeting the release of active chemotherapy in tumour tissue. Despite the high dose level in the fifth cohort which is approximately 2.25 times a typical dose of doxorubicin, AVA6000 has continued to be well tolerated by patients with a marked reduction in the incidence and severity of the typical toxicities associated with the standard doxorubicin chemotherapy administration.

The emerging positive safety and pharmacokinetic data from the study support the potential clinical differentiation of AVA6000 over doxorubicin. This includes: (i) higher dosing of AVA6000 compared to standard doxorubicin, (ii) more frequent dosing of AVA6000 compared to doxorubicin - doxorubicin is typically dosed every three weeks in order for patients to recover from the side effects of treatment, (iii) the ability to administer many more cycles of AVA6000 compared to doxorubicin.

A total of 29 patients with a range of advanced and/or metastatic solid tumours have now been dosed at the clinical trial in sites in the UK and United States. On the basis of the very favourable safety profile of AVA6000 in the study to date, the Safety Data Monitoring Committee (SDMC) has recommended continuation to the sixth dose cohort at 310 mg/m2, which is equivalent to 2.7 times the standard dose of doxorubicin. 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 of Avacta Group plc commented:

"The continued positive safety profile of AVA6000 at these dose levels compared with standard doxorubicin is remarkable. We are seeing a significant reduction in the incidence and severity of all doxorubicin side effects. Analysis of the tumour biopsies to date also confirms that enough doxorubicin is being released in the tumour to have a therapeutic effect. If even higher doses of AVA6000 are tolerated then this may make a significant difference to the outcomes for patients in the upcoming efficacy study.

"We are keen to progress onto the Phase 1b efficacy study as soon as possible following completion of the dose finding Phase 1a study. The dose expansion Phase 1b study will provide an initial evaluation of efficacy and of the relative improvement in patient outcomes and quality of life of different dosing regimens of AVA6000 compared with the standard doxorubicin regimen."

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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. In May 2023, Avacta acquired Coris Bioconcept a Belgium based lateral flow test developer and manufacturer adding a broad range of marketed professional-use rapid tests into the Diagnostics Division. 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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