Avacta Group plc announced the successful completion of the first cohort and dosing of 3 patients in the second cohort in the dose escalation study of Arm 2 of its Phase 1 trial for AVA6000, a peptide drug conjugate form of doxorubicin chemotherapy. In addition, a sub-study utilizing FAPI-PET scanning at baseline has also commenced to further characterize the full burden of FAP-positive disease in patients. The Phase 1 trial is evaluating the safety and tolerability of AVA6000, Avacta's lead programme, leveraging its proprietary pre|CISION??

technology. FAPI-74 PET is currently in clinical development and for investigational use only. Avacta is on track for stated goals in the second half of 2024, including the commencement of the dose expansion Phase 1b efficacy study and presenting further data from the AVA6000 trial.

The data from this expansion study will be used to inform the optimal choice of a single indication for a Phase 2 efficacy study which will follow the expansions. Phase 1a Arm 1: Seven dose cohorts (n=42) were completed in the Phase 1a Arm 1 of the trial with a dosing schedule of every three weeks ("Q3W"). Data from Arm 1 of the trial, presented at the American Association for Cancer Research (AACR) meeting in April, demonstrated that AVA6000 delivers high concentrations of doxorubic in the tumor microenvironment ("TME") relative to plasma, resulting in significant antitumor activity in patients whose tumors have over-expression of FAP.

A significant reduction in the frequency and severity of the known doxorubicin toxicities was observed across the dosing range in Arm 1. A maximum tolerated dose has not been reached in the three-weekly dose escalation study despite dosing approximately 3.5x the normal level of doxorubic In the highest and final dose cohort in Arm 1 of the Phase 1a study. The pre|CISION?? platform is a highly specific substrate for fibroblast activation protein (FAP) which is upregulated in most solid tumor compared with healthy tissues.

The pre|CISIONtm platform harnesses this tumor specific protease to activate pre|CISION?? peptide drug conjugates and pre|CISION?? antibody/Affimer®?

drug conjugates in the tumor microenvironment, reducing systemic exposure and toxicity, allowing dosing to be optimised to deliver the best outcomes for patients. The lead pre|CISION?? programme AVA6000, a peptides drug conjugate form of doesxorubicin, is in Phase 1 studies.

It has shown a dramatic improvement in safety and tolerability in clinical trials to date compared with standard doxorubicin and preliminary signs of clinical activity in patients.